Warning! Contract bytecode has been changed and doesn't match the verified one. Therefore, interaction with this smart contract may be risky.
- Contract name:
- BasicLens
- Optimization enabled
- true
- Compiler version
- v0.8.10+commit.fc410830
- Optimization runs
- 200
- Verified at
- 2023-07-19T16:24:37.386670Z
contracts/Lens/BasicLens.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "../EIP20Interface.sol"; import "../PriceOracle.sol"; import "../RewardDistributor.sol"; interface ComptrollerLensInterface { function claimComp(address) external; function rewardDistributor() external view returns (address); } contract BasicLens { function rewardsAccrued( ComptrollerLensInterface comptroller, address account ) external returns (address[] memory rewardTokens, uint256[] memory accrued) { address externalRewardDistributor = comptroller.rewardDistributor(); rewardTokens = RewardDistributor(externalRewardDistributor) .getRewardTokens(); uint256[] memory beforeBalances = getBalancesInternal( rewardTokens, account ); comptroller.claimComp(account); uint256[] memory afterBalances = getBalancesInternal( rewardTokens, account ); accrued = new uint256[](rewardTokens.length); for (uint256 i = 0; i < rewardTokens.length; i++) { accrued[i] = afterBalances[i] - beforeBalances[i]; } } function getBalancesInternal( address[] memory tokens, address account ) internal view returns (uint256[] memory balances) { balances = new uint256[](tokens.length); for (uint256 i = 0; i < tokens.length; i++) { balances[i] = EIP20Interface(tokens[i]).balanceOf(account); } } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol) pragma solidity ^0.8.0; import "../utils/ContextUpgradeable.sol"; import "../proxy/utils/Initializable.sol"; /** * @dev Contract module which provides a basic access control mechanism, where * there is an account (an owner) that can be granted exclusive access to * specific functions. * * By default, the owner account will be the one that deploys the contract. This * can later be changed with {transferOwnership}. * * This module is used through inheritance. It will make available the modifier * `onlyOwner`, which can be applied to your functions to restrict their use to * the owner. */ abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ function __Ownable_init() internal onlyInitializing { __Ownable_init_unchained(); } function __Ownable_init_unchained() internal onlyInitializing { _transferOwnership(_msgSender()); } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { _checkOwner(); _; } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if the sender is not the owner. */ function _checkOwner() internal view virtual { require(owner() == _msgSender(), "Ownable: caller is not the owner"); } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { _transferOwnership(address(0)); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); _transferOwnership(newOwner); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Internal function without access restriction. */ function _transferOwnership(address newOwner) internal virtual { address oldOwner = _owner; _owner = newOwner; emit OwnershipTransferred(oldOwner, newOwner); } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[49] private __gap; }
@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.1) (proxy/utils/Initializable.sol) pragma solidity ^0.8.2; import "../../utils/AddressUpgradeable.sol"; /** * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect. * * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in * case an upgrade adds a module that needs to be initialized. * * For example: * * [.hljs-theme-light.nopadding] * ``` * contract MyToken is ERC20Upgradeable { * function initialize() initializer public { * __ERC20_init("MyToken", "MTK"); * } * } * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable { * function initializeV2() reinitializer(2) public { * __ERC20Permit_init("MyToken"); * } * } * ``` * * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}. * * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity. * * [CAUTION] * ==== * Avoid leaving a contract uninitialized. * * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed: * * [.hljs-theme-light.nopadding] * ``` * /// @custom:oz-upgrades-unsafe-allow constructor * constructor() { * _disableInitializers(); * } * ``` * ==== */ abstract contract Initializable { /** * @dev Indicates that the contract has been initialized. * @custom:oz-retyped-from bool */ uint8 private _initialized; /** * @dev Indicates that the contract is in the process of being initialized. */ bool private _initializing; /** * @dev Triggered when the contract has been initialized or reinitialized. */ event Initialized(uint8 version); /** * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope, * `onlyInitializing` functions can be used to initialize parent contracts. * * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a * constructor. * * Emits an {Initialized} event. */ modifier initializer() { bool isTopLevelCall = !_initializing; require( (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1), "Initializable: contract is already initialized" ); _initialized = 1; if (isTopLevelCall) { _initializing = true; } _; if (isTopLevelCall) { _initializing = false; emit Initialized(1); } } /** * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be * used to initialize parent contracts. * * A reinitializer may be used after the original initialization step. This is essential to configure modules that * are added through upgrades and that require initialization. * * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer` * cannot be nested. If one is invoked in the context of another, execution will revert. * * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in * a contract, executing them in the right order is up to the developer or operator. * * WARNING: setting the version to 255 will prevent any future reinitialization. * * Emits an {Initialized} event. */ modifier reinitializer(uint8 version) { require( !_initializing && _initialized < version, "Initializable: contract is already initialized" ); _initialized = version; _initializing = true; _; _initializing = false; emit Initialized(version); } /** * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the * {initializer} and {reinitializer} modifiers, directly or indirectly. */ modifier onlyInitializing() { require(_initializing, "Initializable: contract is not initializing"); _; } /** * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call. * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized * to any version. It is recommended to use this to lock implementation contracts that are designed to be called * through proxies. * * Emits an {Initialized} event the first time it is successfully executed. */ function _disableInitializers() internal virtual { require(!_initializing, "Initializable: contract is initializing"); if (_initialized < type(uint8).max) { _initialized = type(uint8).max; emit Initialized(type(uint8).max); } } /** * @dev Returns the highest version that has been initialized. See {reinitializer}. */ function _getInitializedVersion() internal view returns (uint8) { return _initialized; } /** * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}. */ function _isInitializing() internal view returns (bool) { return _initializing; } }
@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol) pragma solidity ^0.8.1; /** * @dev Collection of functions related to the address type */ library AddressUpgradeable { /** * @dev Returns true if `account` is a contract. * * [IMPORTANT] * ==== * It is unsafe to assume that an address for which this function returns * false is an externally-owned account (EOA) and not a contract. * * Among others, `isContract` will return false for the following * types of addresses: * * - an externally-owned account * - a contract in construction * - an address where a contract will be created * - an address where a contract lived, but was destroyed * ==== * * [IMPORTANT] * ==== * You shouldn't rely on `isContract` to protect against flash loan attacks! * * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract * constructor. * ==== */ function isContract(address account) internal view returns (bool) { // This method relies on extcodesize/address.code.length, which returns 0 // for contracts in construction, since the code is only stored at the end // of the constructor execution. return account.code.length > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); (bool success, ) = recipient.call{value: amount}(""); require(success, "Address: unable to send value, recipient may have reverted"); } /** * @dev Performs a Solidity function call using a low level `call`. A * plain `call` is an unsafe replacement for a function call: use this * function instead. * * If `target` reverts with a revert reason, it is bubbled up by this * function (like regular Solidity function calls). * * Returns the raw returned data. To convert to the expected return value, * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. * * Requirements: * * - `target` must be a contract. * - calling `target` with `data` must not revert. * * _Available since v3.1._ */ function functionCall(address target, bytes memory data) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, "Address: low-level call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with * `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCall( address target, bytes memory data, string memory errorMessage ) internal returns (bytes memory) { return functionCallWithValue(target, data, 0, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but also transferring `value` wei to `target`. * * Requirements: * * - the calling contract must have an ETH balance of at least `value`. * - the called Solidity function must be `payable`. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value ) internal returns (bytes memory) { return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); } /** * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but * with `errorMessage` as a fallback revert reason when `target` reverts. * * _Available since v3.1._ */ function functionCallWithValue( address target, bytes memory data, uint256 value, string memory errorMessage ) internal returns (bytes memory) { require(address(this).balance >= value, "Address: insufficient balance for call"); (bool success, bytes memory returndata) = target.call{value: value}(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { return functionStaticCall(target, data, "Address: low-level static call failed"); } /** * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], * but performing a static call. * * _Available since v3.3._ */ function functionStaticCall( address target, bytes memory data, string memory errorMessage ) internal view returns (bytes memory) { (bool success, bytes memory returndata) = target.staticcall(data); return verifyCallResultFromTarget(target, success, returndata, errorMessage); } /** * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract. * * _Available since v4.8._ */ function verifyCallResultFromTarget( address target, bool success, bytes memory returndata, string memory errorMessage ) internal view returns (bytes memory) { if (success) { if (returndata.length == 0) { // only check isContract if the call was successful and the return data is empty // otherwise we already know that it was a contract require(isContract(target), "Address: call to non-contract"); } return returndata; } else { _revert(returndata, errorMessage); } } /** * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the * revert reason or using the provided one. * * _Available since v4.3._ */ function verifyCallResult( bool success, bytes memory returndata, string memory errorMessage ) internal pure returns (bytes memory) { if (success) { return returndata; } else { _revert(returndata, errorMessage); } } function _revert(bytes memory returndata, string memory errorMessage) private pure { // Look for revert reason and bubble it up if present if (returndata.length > 0) { // The easiest way to bubble the revert reason is using memory via assembly /// @solidity memory-safe-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } }
@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol
// SPDX-License-Identifier: MIT // OpenZeppelin Contracts v4.4.1 (utils/Context.sol) pragma solidity ^0.8.0; import "../proxy/utils/Initializable.sol"; /** * @dev Provides information about the current execution context, including the * sender of the transaction and its data. While these are generally available * via msg.sender and msg.data, they should not be accessed in such a direct * manner, since when dealing with meta-transactions the account sending and * paying for execution may not be the actual sender (as far as an application * is concerned). * * This contract is only required for intermediate, library-like contracts. */ abstract contract ContextUpgradeable is Initializable { function __Context_init() internal onlyInitializing { } function __Context_init_unchained() internal onlyInitializing { } function _msgSender() internal view virtual returns (address) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } /** * @dev This empty reserved space is put in place to allow future versions to add new * variables without shifting down storage in the inheritance chain. * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps */ uint256[50] private __gap; }
contracts/CToken.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./CTokenInterfaces.sol"; import "./ErrorReporter.sol"; import "./EIP20Interface.sol"; import "./InterestRateModel.sol"; import "./ExponentialNoError.sol"; /** * @title Compound's CToken Contract * @notice Abstract base for CTokens * @author Compound */ abstract contract CToken is CTokenInterface, ExponentialNoError, TokenErrorReporter { /** * @notice Initialize the money market * @param comptroller_ The address of the Comptroller * @param interestRateModel_ The address of the interest rate model * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18 * @param name_ EIP-20 name of this token * @param symbol_ EIP-20 symbol of this token * @param decimals_ EIP-20 decimal precision of this token */ function initialize( ComptrollerInterface comptroller_, InterestRateModel interestRateModel_, uint256 initialExchangeRateMantissa_, string memory name_, string memory symbol_, uint8 decimals_ ) public { require(msg.sender == admin, "only admin may initialize the market"); require( accrualBlockNumber == 0 && borrowIndex == 0, "market may only be initialized once" ); // Set initial exchange rate initialExchangeRateMantissa = initialExchangeRateMantissa_; require( initialExchangeRateMantissa > 0, "initial exchange rate must be greater than zero." ); // Set the comptroller uint256 err = _setComptroller(comptroller_); require(err == NO_ERROR, "setting comptroller failed"); // Initialize block number and borrow index (block number mocks depend on comptroller being set) accrualBlockNumber = getBlockNumber(); borrowIndex = mantissaOne; // Set the interest rate model (depends on block number / borrow index) err = _setInterestRateModelFresh(interestRateModel_); require(err == NO_ERROR, "setting interest rate model failed"); name = name_; symbol = symbol_; decimals = decimals_; // The counter starts true to prevent changing it from zero to non-zero (i.e. smaller cost/refund) _notEntered = true; } /** * @notice Transfer `tokens` tokens from `src` to `dst` by `spender` * @dev Called by both `transfer` and `transferFrom` internally * @param spender The address of the account performing the transfer * @param src The address of the source account * @param dst The address of the destination account * @param tokens The number of tokens to transfer * @return 0 if the transfer succeeded, else revert */ function transferTokens( address spender, address src, address dst, uint256 tokens ) internal returns (uint256) { /* Fail if transfer not allowed */ uint256 allowed = comptroller.transferAllowed( address(this), src, dst, tokens ); if (allowed != 0) { revert TransferComptrollerRejection(allowed); } /* Do not allow self-transfers */ if (src == dst) { revert TransferNotAllowed(); } /* Get the allowance, infinite for the account owner */ uint256 startingAllowance = 0; if (spender == src) { startingAllowance = type(uint256).max; } else { startingAllowance = transferAllowances[src][spender]; } /* Do the calculations, checking for {under,over}flow */ uint256 allowanceNew = startingAllowance - tokens; uint256 srcTokensNew = accountTokens[src] - tokens; uint256 dstTokensNew = accountTokens[dst] + tokens; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) accountTokens[src] = srcTokensNew; accountTokens[dst] = dstTokensNew; /* Eat some of the allowance (if necessary) */ if (startingAllowance != type(uint256).max) { transferAllowances[src][spender] = allowanceNew; } /* We emit a Transfer event */ emit Transfer(src, dst, tokens); // unused function // comptroller.transferVerify(address(this), src, dst, tokens); return NO_ERROR; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, msg.sender, dst, amount) == NO_ERROR; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external override nonReentrant returns (bool) { return transferTokens(msg.sender, src, dst, amount) == NO_ERROR; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (uint256.max means infinite) * @return Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external override returns (bool) { address src = msg.sender; transferAllowances[src][spender] = amount; emit Approval(src, spender, amount); return true; } /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view override returns (uint256) { return transferAllowances[owner][spender]; } /** * @notice Get the token balance of the `owner` * @param owner The address of the account to query * @return The number of tokens owned by `owner` */ function balanceOf(address owner) external view override returns (uint256) { return accountTokens[owner]; } /** * @notice Get the underlying balance of the `owner` * @dev This also accrues interest in a transaction * @param owner The address of the account to query * @return The amount of underlying owned by `owner` */ function balanceOfUnderlying( address owner ) external override returns (uint256) { Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()}); return mul_ScalarTruncate(exchangeRate, accountTokens[owner]); } /** * @notice Get a snapshot of the account's balances, and the cached exchange rate * @dev This is used by comptroller to more efficiently perform liquidity checks. * @param account Address of the account to snapshot * @return (possible error, token balance, borrow balance, exchange rate mantissa) */ function getAccountSnapshot( address account ) external view override returns (uint256, uint256, uint256, uint256) { return ( NO_ERROR, accountTokens[account], borrowBalanceStoredInternal(account), exchangeRateStoredInternal() ); } /** * @dev Function to simply retrieve block number * This exists mainly for inheriting test contracts to stub this result. */ function getBlockNumber() internal view virtual returns (uint256) { return block.timestamp; } /** * @notice Returns the current per-block borrow interest rate for this cToken * @return The borrow interest rate per block, scaled by 1e18 */ function borrowRatePerBlock() external view override returns (uint256) { return interestRateModel.getBorrowRate( getCashPrior(), totalBorrows, totalReserves ); } /** * @notice Returns the current per-block supply interest rate for this cToken * @return The supply interest rate per block, scaled by 1e18 */ function supplyRatePerBlock() external view override returns (uint256) { return interestRateModel.getSupplyRate( getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa ); } /** * @notice Returns the current total borrows plus accrued interest * @return The total borrows with interest */ function totalBorrowsCurrent() external override nonReentrant returns (uint256) { accrueInterest(); return totalBorrows; } /** * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex * @param account The address whose balance should be calculated after updating borrowIndex * @return The calculated balance */ function borrowBalanceCurrent( address account ) external override nonReentrant returns (uint256) { accrueInterest(); return borrowBalanceStored(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return The calculated balance */ function borrowBalanceStored( address account ) public view override returns (uint256) { return borrowBalanceStoredInternal(account); } /** * @notice Return the borrow balance of account based on stored data * @param account The address whose balance should be calculated * @return (error code, the calculated balance or 0 if error code is non-zero) */ function borrowBalanceStoredInternal( address account ) internal view returns (uint256) { /* Get borrowBalance and borrowIndex */ BorrowSnapshot storage borrowSnapshot = accountBorrows[account]; /* If borrowBalance = 0 then borrowIndex is likely also 0. * Rather than failing the calculation with a division by 0, we immediately return 0 in this case. */ if (borrowSnapshot.principal == 0) { return 0; } /* Calculate new borrow balance using the interest index: * recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex */ uint256 principalTimesIndex = borrowSnapshot.principal * borrowIndex; return principalTimesIndex / borrowSnapshot.interestIndex; } /** * @notice Accrue interest then return the up-to-date exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateCurrent() public override nonReentrant returns (uint256) { accrueInterest(); return exchangeRateStored(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return Calculated exchange rate scaled by 1e18 */ function exchangeRateStored() public view override returns (uint256) { return exchangeRateStoredInternal(); } /** * @notice Calculates the exchange rate from the underlying to the CToken * @dev This function does not accrue interest before calculating the exchange rate * @return calculated exchange rate scaled by 1e18 */ function exchangeRateStoredInternal() internal view virtual returns (uint256) { uint256 _totalSupply = totalSupply; if (_totalSupply == 0) { /* * If there are no tokens minted: * exchangeRate = initialExchangeRate */ return initialExchangeRateMantissa; } else { /* * Otherwise: * exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply */ uint256 totalCash = getCashPrior(); uint256 cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves; uint256 exchangeRate = (cashPlusBorrowsMinusReserves * expScale) / _totalSupply; return exchangeRate; } } /** * @notice Get cash balance of this cToken in the underlying asset * @return The quantity of underlying asset owned by this contract */ function getCash() external view override returns (uint256) { return getCashPrior(); } /** * @notice Applies accrued interest to total borrows and reserves * @dev This calculates interest accrued from the last checkpointed block * up to the current block and writes new checkpoint to storage. */ function accrueInterest() public virtual override returns (uint256) { /* Remember the initial block number */ uint256 currentBlockNumber = getBlockNumber(); uint256 accrualBlockNumberPrior = accrualBlockNumber; /* Short-circuit accumulating 0 interest */ if (accrualBlockNumberPrior == currentBlockNumber) { return NO_ERROR; } /* Read the previous values out of storage */ uint256 cashPrior = getCashPrior(); uint256 borrowsPrior = totalBorrows; uint256 reservesPrior = totalReserves; uint256 borrowIndexPrior = borrowIndex; /* Calculate the current borrow interest rate */ uint256 borrowRateMantissa = interestRateModel.getBorrowRate( cashPrior, borrowsPrior, reservesPrior ); require( borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high" ); /* Calculate the number of blocks elapsed since the last accrual */ uint256 blockDelta = currentBlockNumber - accrualBlockNumberPrior; /* * Calculate the interest accumulated into borrows and reserves and the new index: * simpleInterestFactor = borrowRate * blockDelta * interestAccumulated = simpleInterestFactor * totalBorrows * totalBorrowsNew = interestAccumulated + totalBorrows * totalReservesNew = interestAccumulated * reserveFactor + totalReserves * borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex */ Exp memory simpleInterestFactor = mul_( Exp({mantissa: borrowRateMantissa}), blockDelta ); uint256 interestAccumulated = mul_ScalarTruncate( simpleInterestFactor, borrowsPrior ); uint256 totalBorrowsNew = interestAccumulated + borrowsPrior; uint256 totalReservesNew = mul_ScalarTruncateAddUInt( Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior ); uint256 borrowIndexNew = mul_ScalarTruncateAddUInt( simpleInterestFactor, borrowIndexPrior, borrowIndexPrior ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the previously calculated values into storage */ accrualBlockNumber = currentBlockNumber; borrowIndex = borrowIndexNew; totalBorrows = totalBorrowsNew; totalReserves = totalReservesNew; /* We emit an AccrueInterest event */ emit AccrueInterest( cashPrior, interestAccumulated, borrowIndexNew, totalBorrowsNew ); return NO_ERROR; } /** * @notice Sender supplies assets into the market and receives cTokens in exchange * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param mintAmount The amount of the underlying asset to supply */ function mintInternal(uint256 mintAmount) internal nonReentrant { accrueInterest(); // mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to mintFresh(msg.sender, mintAmount); } /** * @notice User supplies assets into the market and receives cTokens in exchange * @dev Assumes interest has already been accrued up to the current block * @param minter The address of the account which is supplying the assets * @param mintAmount The amount of the underlying asset to supply */ function mintFresh(address minter, uint256 mintAmount) internal { /* Fail if mint not allowed */ uint256 allowed = comptroller.mintAllowed( address(this), minter, mintAmount ); if (allowed != 0) { revert MintComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert MintFreshnessCheck(); } Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call `doTransferIn` for the minter and the mintAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * `doTransferIn` reverts if anything goes wrong, since we can't be sure if * side-effects occurred. The function returns the amount actually transferred, * in case of a fee. On success, the cToken holds an additional `actualMintAmount` * of cash. */ uint256 actualMintAmount = doTransferIn(minter, mintAmount); /* * We get the current exchange rate and calculate the number of cTokens to be minted: * mintTokens = actualMintAmount / exchangeRate */ uint256 mintTokens = div_(actualMintAmount, exchangeRate); /* * We calculate the new total supply of cTokens and minter token balance, checking for overflow: * totalSupplyNew = totalSupply + mintTokens * accountTokensNew = accountTokens[minter] + mintTokens * And write them into storage */ totalSupply = totalSupply + mintTokens; accountTokens[minter] = accountTokens[minter] + mintTokens; /* We emit a Mint event, and a Transfer event */ emit Mint(minter, actualMintAmount, mintTokens); emit Transfer(address(this), minter, mintTokens); /* We call the defense hook */ comptroller.mintVerify( address(this), minter, actualMintAmount, mintTokens ); } /** * @notice Sender redeems cTokens in exchange for the underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemTokens The number of cTokens to redeem into underlying */ function redeemInternal(uint256 redeemTokens) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), redeemTokens, 0); } /** * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset * @dev Accrues interest whether or not the operation succeeds, unless reverted * @param redeemAmount The amount of underlying to receive from redeeming cTokens */ function redeemUnderlyingInternal( uint256 redeemAmount ) internal nonReentrant { accrueInterest(); // redeemFresh emits redeem-specific logs on errors, so we don't need to redeemFresh(payable(msg.sender), 0, redeemAmount); } /** * @notice User redeems cTokens in exchange for the underlying asset * @dev Assumes interest has already been accrued up to the current block * @param redeemer The address of the account which is redeeming the tokens * @param redeemTokensIn The number of cTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be non-zero) * @param redeemAmountIn The number of underlying tokens to receive from redeeming cTokens (only one of redeemTokensIn or redeemAmountIn may be non-zero) */ function redeemFresh( address payable redeemer, uint256 redeemTokensIn, uint256 redeemAmountIn ) internal { require( redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero" ); /* exchangeRate = invoke Exchange Rate Stored() */ Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 redeemTokens; uint256 redeemAmount; /* If redeemTokensIn > 0: */ if (redeemTokensIn > 0) { /* * We calculate the exchange rate and the amount of underlying to be redeemed: * redeemTokens = redeemTokensIn * redeemAmount = redeemTokensIn x exchangeRateCurrent */ redeemTokens = redeemTokensIn; redeemAmount = mul_ScalarTruncate(exchangeRate, redeemTokensIn); } else { /* * We get the current exchange rate and calculate the amount to be redeemed: * redeemTokens = redeemAmountIn / exchangeRate * redeemAmount = redeemAmountIn */ redeemTokens = div_(redeemAmountIn, exchangeRate); redeemAmount = redeemAmountIn; } /* Fail if redeem not allowed */ uint256 allowed = comptroller.redeemAllowed( address(this), redeemer, redeemTokens ); if (allowed != 0) { revert RedeemComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RedeemFreshnessCheck(); } /* Fail gracefully if protocol has insufficient cash */ if (getCashPrior() < redeemAmount) { revert RedeemTransferOutNotPossible(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing reduced supply before external transfer. */ totalSupply = totalSupply - redeemTokens; accountTokens[redeemer] = accountTokens[redeemer] - redeemTokens; /* * We invoke doTransferOut for the redeemer and the redeemAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken has redeemAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(redeemer, redeemAmount); /* We emit a Transfer event, and a Redeem event */ emit Transfer(redeemer, address(this), redeemTokens); emit Redeem(redeemer, redeemAmount, redeemTokens); /* We call the defense hook */ comptroller.redeemVerify( address(this), redeemer, redeemAmount, redeemTokens ); } /** * @notice Sender borrows assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowInternal(uint256 borrowAmount) internal nonReentrant { accrueInterest(); // borrowFresh emits borrow-specific logs on errors, so we don't need to borrowFresh(payable(msg.sender), borrowAmount); } /** * @notice Users borrow assets from the protocol to their own address * @param borrowAmount The amount of the underlying asset to borrow */ function borrowFresh( address payable borrower, uint256 borrowAmount ) internal { /* Fail if borrow not allowed */ uint256 allowed = comptroller.borrowAllowed( address(this), borrower, borrowAmount ); if (allowed != 0) { revert BorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert BorrowFreshnessCheck(); } /* Fail gracefully if protocol has insufficient underlying cash */ if (getCashPrior() < borrowAmount) { revert BorrowCashNotAvailable(); } /* * We calculate the new borrower and total borrow balances, failing on overflow: * accountBorrowNew = accountBorrow + borrowAmount * totalBorrowsNew = totalBorrows + borrowAmount */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); uint256 accountBorrowsNew = accountBorrowsPrev + borrowAmount; uint256 totalBorrowsNew = totalBorrows + borrowAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We write the previously calculated values into storage. * Note: Avoid token reentrancy attacks by writing increased borrow before external transfer. `*/ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* * We invoke doTransferOut for the borrower and the borrowAmount. * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken borrowAmount less of cash. * doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. */ doTransferOut(borrower, borrowAmount); /* We emit a Borrow event */ emit Borrow(borrower, borrowAmount, accountBorrowsNew, totalBorrowsNew); } /** * @notice Sender repays their own borrow * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowInternal(uint256 repayAmount) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, msg.sender, repayAmount); } /** * @notice Sender repays a borrow belonging to borrower * @param borrower the account with the debt being payed off * @param repayAmount The amount to repay, or -1 for the full outstanding amount */ function repayBorrowBehalfInternal( address borrower, uint256 repayAmount ) internal nonReentrant { accrueInterest(); // repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to repayBorrowFresh(msg.sender, borrower, repayAmount); } /** * @notice Borrows are repaid by another user (possibly the borrower). * @param payer the account paying off the borrow * @param borrower the account with the debt being payed off * @param repayAmount the amount of underlying tokens being returned, or -1 for the full outstanding amount * @return (uint) the actual repayment amount. */ function repayBorrowFresh( address payer, address borrower, uint256 repayAmount ) internal returns (uint256) { /* Fail if repayBorrow not allowed */ uint256 allowed = comptroller.repayBorrowAllowed( address(this), payer, borrower, repayAmount ); if (allowed != 0) { revert RepayBorrowComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert RepayBorrowFreshnessCheck(); } /* We fetch the amount the borrower owes, with accumulated interest */ uint256 accountBorrowsPrev = borrowBalanceStoredInternal(borrower); /* If repayAmount == -1, repayAmount = accountBorrows */ uint256 repayAmountFinal = repayAmount == type(uint256).max ? accountBorrowsPrev : repayAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the payer and the repayAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional repayAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ uint256 actualRepayAmount = doTransferIn(payer, repayAmountFinal); /* * We calculate the new borrower and total borrow balances, failing on underflow: * accountBorrowsNew = accountBorrows - actualRepayAmount * totalBorrowsNew = totalBorrows - actualRepayAmount */ uint256 accountBorrowsNew = accountBorrowsPrev - actualRepayAmount; uint256 totalBorrowsNew = totalBorrows - actualRepayAmount; /* We write the previously calculated values into storage */ accountBorrows[borrower].principal = accountBorrowsNew; accountBorrows[borrower].interestIndex = borrowIndex; totalBorrows = totalBorrowsNew; /* We emit a RepayBorrow event */ emit RepayBorrow( payer, borrower, actualRepayAmount, accountBorrowsNew, totalBorrowsNew ); return actualRepayAmount; } /** * @notice The sender liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowInternal( address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal nonReentrant { accrueInterest(); uint256 error = cTokenCollateral.accrueInterest(); if (error != NO_ERROR) { // accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed revert LiquidateAccrueCollateralInterestFailed(error); } // liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to liquidateBorrowFresh( msg.sender, borrower, repayAmount, cTokenCollateral ); } /** * @notice The liquidator liquidates the borrowers collateral. * The collateral seized is transferred to the liquidator. * @param borrower The borrower of this cToken to be liquidated * @param liquidator The address repaying the borrow and seizing collateral * @param cTokenCollateral The market in which to seize collateral from the borrower * @param repayAmount The amount of the underlying borrowed asset to repay */ function liquidateBorrowFresh( address liquidator, address borrower, uint256 repayAmount, CTokenInterface cTokenCollateral ) internal { /* Fail if liquidate not allowed */ uint256 allowed = comptroller.liquidateBorrowAllowed( address(this), address(cTokenCollateral), liquidator, borrower, repayAmount ); if (allowed != 0) { revert LiquidateComptrollerRejection(allowed); } /* Verify market's block number equals current block number */ if (accrualBlockNumber != getBlockNumber()) { revert LiquidateFreshnessCheck(); } /* Verify cTokenCollateral market's block number equals current block number */ if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) { revert LiquidateCollateralFreshnessCheck(); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateLiquidatorIsBorrower(); } /* Fail if repayAmount = 0 */ if (repayAmount == 0) { revert LiquidateCloseAmountIsZero(); } /* Fail if repayAmount = -1 */ if (repayAmount == type(uint256).max) { revert LiquidateCloseAmountIsUintMax(); } /* Fail if repayBorrow fails */ uint256 actualRepayAmount = repayBorrowFresh( liquidator, borrower, repayAmount ); ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We calculate the number of collateral tokens that will be seized */ (uint256 amountSeizeError, uint256 seizeTokens) = comptroller .liquidateCalculateSeizeTokens( address(this), address(cTokenCollateral), actualRepayAmount ); require( amountSeizeError == NO_ERROR, "LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED" ); /* Revert if borrower collateral token balance < seizeTokens */ require( cTokenCollateral.balanceOf(borrower) >= seizeTokens, "LIQUIDATE_SEIZE_TOO_MUCH" ); // If this is also the collateral, run seizeInternal to avoid re-entrancy, otherwise make an external call if (address(cTokenCollateral) == address(this)) { seizeInternal(address(this), liquidator, borrower, seizeTokens); } else { require( cTokenCollateral.seize(liquidator, borrower, seizeTokens) == NO_ERROR, "token seizure failed" ); } /* We emit a LiquidateBorrow event */ emit LiquidateBorrow( liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens ); } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Will fail unless called by another cToken during the process of liquidation. * Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter. * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function seize( address liquidator, address borrower, uint256 seizeTokens ) external override nonReentrant returns (uint256) { seizeInternal(msg.sender, liquidator, borrower, seizeTokens); return NO_ERROR; } /** * @notice Transfers collateral tokens (this market) to the liquidator. * @dev Called only during an in-kind liquidation, or by liquidateBorrow during the liquidation of another CToken. * Its absolutely critical to use msg.sender as the seizer cToken and not a parameter. * @param seizerToken The contract seizing the collateral (i.e. borrowed cToken) * @param liquidator The account receiving seized collateral * @param borrower The account having collateral seized * @param seizeTokens The number of cTokens to seize */ function seizeInternal( address seizerToken, address liquidator, address borrower, uint256 seizeTokens ) internal { /* Fail if seize not allowed */ uint256 allowed = comptroller.seizeAllowed( address(this), seizerToken, liquidator, borrower, seizeTokens ); if (allowed != 0) { revert LiquidateSeizeComptrollerRejection(allowed); } /* Fail if borrower = liquidator */ if (borrower == liquidator) { revert LiquidateSeizeLiquidatorIsBorrower(); } /* * We calculate the new borrower and liquidator token balances, failing on underflow/overflow: * borrowerTokensNew = accountTokens[borrower] - seizeTokens * liquidatorTokensNew = accountTokens[liquidator] + seizeTokens */ uint256 protocolSeizeTokens = mul_( seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}) ); uint256 liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens; Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()}); uint256 protocolSeizeAmount = mul_ScalarTruncate( exchangeRate, protocolSeizeTokens ); uint256 totalReservesNew = totalReserves + protocolSeizeAmount; ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* We write the calculated values into storage */ totalReserves = totalReservesNew; totalSupply = totalSupply - protocolSeizeTokens; accountTokens[borrower] = accountTokens[borrower] - seizeTokens; accountTokens[liquidator] = accountTokens[liquidator] + liquidatorSeizeTokens; /* Emit a Transfer event */ emit Transfer(borrower, liquidator, liquidatorSeizeTokens); emit Transfer(borrower, address(this), protocolSeizeTokens); emit ReservesAdded( address(this), protocolSeizeAmount, totalReservesNew ); } /*** Admin Functions ***/ /** * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer. * @param newPendingAdmin New pending admin. * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setPendingAdmin( address payable newPendingAdmin ) external override returns (uint256) { // Check caller = admin if (msg.sender != admin) { revert SetPendingAdminOwnerCheck(); } // Save current value, if any, for inclusion in log address oldPendingAdmin = pendingAdmin; // Store pendingAdmin with value newPendingAdmin pendingAdmin = newPendingAdmin; // Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin) emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin); return NO_ERROR; } /** * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin * @dev Admin function for pending admin to accept role and update admin * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _acceptAdmin() external override returns (uint256) { // Check caller is pendingAdmin and pendingAdmin ≠ address(0) if (msg.sender != pendingAdmin || msg.sender == address(0)) { revert AcceptAdminPendingAdminCheck(); } // Save current values for inclusion in log address oldAdmin = admin; address oldPendingAdmin = pendingAdmin; // Store admin with value pendingAdmin admin = pendingAdmin; // Clear the pending value pendingAdmin = payable(address(0)); emit NewAdmin(oldAdmin, admin); emit NewPendingAdmin(oldPendingAdmin, pendingAdmin); return NO_ERROR; } /** * @notice Sets a new comptroller for the market * @dev Admin function to set a new comptroller * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setComptroller( ComptrollerInterface newComptroller ) public override returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetComptrollerOwnerCheck(); } ComptrollerInterface oldComptroller = comptroller; // Ensure invoke comptroller.isComptroller() returns true require(newComptroller.isComptroller(), "marker method returned false"); // Set market's comptroller to newComptroller comptroller = newComptroller; // Emit NewComptroller(oldComptroller, newComptroller) emit NewComptroller(oldComptroller, newComptroller); return NO_ERROR; } /** * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh * @dev Admin function to accrue interest and set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactor( uint256 newReserveFactorMantissa ) external override nonReentrant returns (uint256) { accrueInterest(); // _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to. return _setReserveFactorFresh(newReserveFactorMantissa); } /** * @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual) * @dev Admin function to set a new reserve factor * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveFactorFresh( uint256 newReserveFactorMantissa ) internal returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveFactorAdminCheck(); } // Verify market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetReserveFactorFreshCheck(); } // Check newReserveFactor ≤ maxReserveFactor if (newReserveFactorMantissa > reserveFactorMaxMantissa) { revert SetReserveFactorBoundsCheck(); } uint256 oldReserveFactorMantissa = reserveFactorMantissa; reserveFactorMantissa = newReserveFactorMantissa; emit NewReserveFactor( oldReserveFactorMantissa, newReserveFactorMantissa ); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring from msg.sender * @param addAmount Amount of addition to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _addReservesInternal( uint256 addAmount ) internal nonReentrant returns (uint256) { accrueInterest(); // _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to. _addReservesFresh(addAmount); return NO_ERROR; } /** * @notice Add reserves by transferring from caller * @dev Requires fresh interest accrual * @param addAmount Amount of addition to reserves * @return (uint, uint) An error code (0=success, otherwise a failure (see ErrorReporter.sol for details)) and the actual amount added, net token fees */ function _addReservesFresh( uint256 addAmount ) internal returns (uint256, uint256) { // totalReserves + actualAddAmount uint256 totalReservesNew; uint256 actualAddAmount; // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert AddReservesFactorFreshCheck(actualAddAmount); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) /* * We call doTransferIn for the caller and the addAmount * Note: The cToken must handle variations between ERC-20 and ETH underlying. * On success, the cToken holds an additional addAmount of cash. * doTransferIn reverts if anything goes wrong, since we can't be sure if side effects occurred. * it returns the amount actually transferred, in case of a fee. */ actualAddAmount = doTransferIn(msg.sender, addAmount); totalReservesNew = totalReserves + actualAddAmount; // Store reserves[n+1] = reserves[n] + actualAddAmount totalReserves = totalReservesNew; /* Emit NewReserves(admin, actualAddAmount, reserves[n+1]) */ emit ReservesAdded(msg.sender, actualAddAmount, totalReservesNew); /* Return (NO_ERROR, actualAddAmount) */ return (NO_ERROR, actualAddAmount); } /** * @notice Admin function to set new reserve guardian * @param newReserveGuardian New reserve guardian address * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setReserveGuardian( address payable newReserveGuardian ) external returns (uint256) { // Check caller is admin if (msg.sender != admin) { revert SetReserveGuardianOwnerCheck(); } // Save current value, if any, for inclusion in log address oldReserveGuardian = reserveGuardian; // Set market's reserveGuardian to newReserveGuardian reserveGuardian = newReserveGuardian; emit NewReserveGuardian(oldReserveGuardian, newReserveGuardian); return NO_ERROR; } /** * @notice Accrues interest and reduces reserves by transferring to admin * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReserves( uint256 reduceAmount ) external override nonReentrant returns (uint256) { accrueInterest(); // _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to. return _reduceReservesFresh(reduceAmount); } /** * @notice Reduces reserves by transferring to admin * @dev Requires fresh interest accrual * @param reduceAmount Amount of reduction to reserves * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _reduceReservesFresh( uint256 reduceAmount ) internal returns (uint256) { // totalReserves - reduceAmount uint256 totalReservesNew; // Check caller is admin if (msg.sender != admin || msg.sender != reserveGuardian) { revert ReduceReservesAdminCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert ReduceReservesFreshCheck(); } // Fail gracefully if protocol has insufficient underlying cash if (getCashPrior() < reduceAmount) { revert ReduceReservesCashNotAvailable(); } // Check reduceAmount ≤ reserves[n] (totalReserves) if (reduceAmount > totalReserves) { revert ReduceReservesCashValidation(); } ///////////////////////// // EFFECTS & INTERACTIONS // (No safe failures beyond this point) totalReservesNew = totalReserves - reduceAmount; // Store reserves[n+1] = reserves[n] - reduceAmount totalReserves = totalReservesNew; // doTransferOut reverts if anything goes wrong, since we can't be sure if side effects occurred. doTransferOut(payable(msg.sender), reduceAmount); emit ReservesReduced(admin, reduceAmount, totalReservesNew); return NO_ERROR; } /** * @notice accrues interest and updates the interest rate model using _setInterestRateModelFresh * @dev Admin function to accrue interest and update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModel( InterestRateModel newInterestRateModel ) public override returns (uint256) { accrueInterest(); // _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to. return _setInterestRateModelFresh(newInterestRateModel); } /** * @notice updates the interest rate model (*requires fresh interest accrual) * @dev Admin function to update the interest rate model * @param newInterestRateModel the new interest rate model to use * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details) */ function _setInterestRateModelFresh( InterestRateModel newInterestRateModel ) internal returns (uint256) { // Used to store old model for use in the event that is emitted on success InterestRateModel oldInterestRateModel; // Check caller is admin if (msg.sender != admin) { revert SetInterestRateModelOwnerCheck(); } // We fail gracefully unless market's block number equals current block number if (accrualBlockNumber != getBlockNumber()) { revert SetInterestRateModelFreshCheck(); } // Track the market's current interest rate model oldInterestRateModel = interestRateModel; // Ensure invoke newInterestRateModel.isInterestRateModel() returns true require( newInterestRateModel.isInterestRateModel(), "marker method returned false" ); // Set the interest rate model to newInterestRateModel interestRateModel = newInterestRateModel; // Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel) emit NewMarketInterestRateModel( oldInterestRateModel, newInterestRateModel ); return NO_ERROR; } /*** Safe Token ***/ /** * @notice Gets balance of this contract in terms of the underlying * @dev This excludes the value of the current message, if any * @return The quantity of underlying owned by this contract */ function getCashPrior() internal view virtual returns (uint256); /** * @dev Performs a transfer in, reverting upon failure. Returns the amount actually transferred to the protocol, in case of a fee. * This may revert due to insufficient balance or insufficient allowance. */ function doTransferIn( address from, uint256 amount ) internal virtual returns (uint256); /** * @dev Performs a transfer out, ideally returning an explanatory error code upon failure rather than reverting. * If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract. * If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions. */ function doTransferOut(address payable to, uint256 amount) internal virtual; /*** Reentrancy Guard ***/ /** * @dev Prevents a contract from calling itself, directly or indirectly. */ modifier nonReentrant() { require(_notEntered, "re-entered"); _notEntered = false; _; _notEntered = true; // get a gas-refund post-Istanbul } }
contracts/CTokenInterfaces.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./ComptrollerInterface.sol"; import "./InterestRateModel.sol"; import "./EIP20NonStandardInterface.sol"; import "./ErrorReporter.sol"; contract CTokenStorage { /** * @dev Guard variable for re-entrancy checks */ bool internal _notEntered; /** * @notice EIP-20 token name for this token */ string public name; /** * @notice EIP-20 token symbol for this token */ string public symbol; /** * @notice EIP-20 token decimals for this token */ uint8 public decimals; // Maximum borrow rate that can ever be applied (.0005% / block) uint internal constant borrowRateMaxMantissa = 0.00004e16; // Maximum fraction of interest that can be set aside for reserves uint internal constant reserveFactorMaxMantissa = 1e18; /** * @notice Administrator for this contract */ address payable public admin; /** * @notice Pending administrator for this contract */ address payable public pendingAdmin; /** * @notice Contract which oversees inter-cToken operations */ ComptrollerInterface public comptroller; /** * @notice Model which tells what the current interest rate should be */ InterestRateModel public interestRateModel; // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0) uint internal initialExchangeRateMantissa; /** * @notice Fraction of interest currently set aside for reserves */ uint public reserveFactorMantissa; /** * @notice Block number that interest was last accrued at */ uint public accrualBlockNumber; /** * @notice Accumulator of the total earned interest rate since the opening of the market */ uint public borrowIndex; /** * @notice Total amount of outstanding borrows of the underlying in this market */ uint public totalBorrows; /** * @notice Total amount of reserves of the underlying held in this market */ uint public totalReserves; /** * @notice Total number of tokens in circulation */ uint public totalSupply; // Official record of token balances for each account mapping(address => uint) internal accountTokens; // Approved token transfer amounts on behalf of others mapping(address => mapping(address => uint)) internal transferAllowances; /** * @notice Container for borrow balance information * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action * @member interestIndex Global borrowIndex as of the most recent balance-changing action */ struct BorrowSnapshot { uint principal; uint interestIndex; } // Mapping of account addresses to outstanding borrow balances mapping(address => BorrowSnapshot) internal accountBorrows; /** * @notice Share of seized collateral that is added to reserves */ uint public constant protocolSeizeShareMantissa = 2.8e16; //2.8% /** * @notice The reserve guardian can reduce the reserves of the market */ address payable public reserveGuardian; } abstract contract CTokenInterface is CTokenStorage { /** * @notice Indicator that this is a CToken contract (for inspection) */ bool public constant isCToken = true; /*** Market Events ***/ /** * @notice Event emitted when interest is accrued */ event AccrueInterest( uint cashPrior, uint interestAccumulated, uint borrowIndex, uint totalBorrows ); /** * @notice Event emitted when tokens are minted */ event Mint(address minter, uint mintAmount, uint mintTokens); /** * @notice Event emitted when tokens are redeemed */ event Redeem(address redeemer, uint redeemAmount, uint redeemTokens); /** * @notice Event emitted when underlying is borrowed */ event Borrow( address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is repaid */ event RepayBorrow( address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows ); /** * @notice Event emitted when a borrow is liquidated */ event LiquidateBorrow( address liquidator, address borrower, uint repayAmount, address cTokenCollateral, uint seizeTokens ); /*** Admin Events ***/ /** * @notice Event emitted when pendingAdmin is changed */ event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin); /** * @notice Event emitted when pendingAdmin is accepted, which means admin is updated */ event NewAdmin(address oldAdmin, address newAdmin); /** * @notice Event emitted when comptroller is changed */ event NewComptroller( ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller ); /** * @notice Event emitted when reserve guardian is changed */ event NewReserveGuardian( address oldReserveGuardian, address newReserveGuardian ); /** * @notice Event emitted when interestRateModel is changed */ event NewMarketInterestRateModel( InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel ); /** * @notice Event emitted when the reserve factor is changed */ event NewReserveFactor( uint oldReserveFactorMantissa, uint newReserveFactorMantissa ); /** * @notice Event emitted when the reserves are added */ event ReservesAdded( address benefactor, uint addAmount, uint newTotalReserves ); /** * @notice Event emitted when the reserves are reduced */ event ReservesReduced( address admin, uint reduceAmount, uint newTotalReserves ); /** * @notice EIP20 Transfer event */ event Transfer(address indexed from, address indexed to, uint amount); /** * @notice EIP20 Approval event */ event Approval(address indexed owner, address indexed spender, uint amount); /*** User Interface ***/ function transfer(address dst, uint amount) external virtual returns (bool); function transferFrom( address src, address dst, uint amount ) external virtual returns (bool); function approve( address spender, uint amount ) external virtual returns (bool); function allowance( address owner, address spender ) external view virtual returns (uint); function balanceOf(address owner) external view virtual returns (uint); function balanceOfUnderlying(address owner) external virtual returns (uint); function getAccountSnapshot( address account ) external view virtual returns (uint, uint, uint, uint); function borrowRatePerBlock() external view virtual returns (uint); function supplyRatePerBlock() external view virtual returns (uint); function totalBorrowsCurrent() external virtual returns (uint); function borrowBalanceCurrent( address account ) external virtual returns (uint); function borrowBalanceStored( address account ) external view virtual returns (uint); function exchangeRateCurrent() external virtual returns (uint); function exchangeRateStored() external view virtual returns (uint); function getCash() external view virtual returns (uint); function accrueInterest() external virtual returns (uint); function seize( address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); /*** Admin Functions ***/ function _setPendingAdmin( address payable newPendingAdmin ) external virtual returns (uint); function _acceptAdmin() external virtual returns (uint); function _setComptroller( ComptrollerInterface newComptroller ) external virtual returns (uint); function _setReserveFactor( uint newReserveFactorMantissa ) external virtual returns (uint); function _reduceReserves(uint reduceAmount) external virtual returns (uint); function _setInterestRateModel( InterestRateModel newInterestRateModel ) external virtual returns (uint); } contract CErc20Storage { /** * @notice Underlying asset for this CToken */ address public underlying; } abstract contract CErc20Interface is CErc20Storage { /*** User Interface ***/ function mint(uint mintAmount) external virtual returns (uint); function redeem(uint redeemTokens) external virtual returns (uint); function redeemUnderlying( uint redeemAmount ) external virtual returns (uint); function borrow(uint borrowAmount) external virtual returns (uint); function repayBorrow(uint repayAmount) external virtual returns (uint); function repayBorrowBehalf( address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrow( address borrower, uint repayAmount, CTokenInterface cTokenCollateral ) external virtual returns (uint); function sweepToken(EIP20NonStandardInterface token) external virtual; /*** Admin Functions ***/ function _addReserves(uint addAmount) external virtual returns (uint); } contract CDelegationStorage { /** * @notice Implementation address for this contract */ address public implementation; } abstract contract CDelegatorInterface is CDelegationStorage { /** * @notice Emitted when implementation is changed */ event NewImplementation( address oldImplementation, address newImplementation ); /** * @notice Called by the admin to update the implementation of the delegator * @param implementation_ The address of the new implementation for delegation * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation */ function _setImplementation( address implementation_, bool allowResign, bytes memory becomeImplementationData ) external virtual; } abstract contract CDelegateInterface is CDelegationStorage { /** * @notice Called by the delegator on a delegate to initialize it for duty * @dev Should revert if any issues arise which make it unfit for delegation * @param data The encoded bytes data for any initialization */ function _becomeImplementation(bytes memory data) external virtual; /** * @notice Called by the delegator on a delegate to forfeit its responsibility */ function _resignImplementation() external virtual; }
contracts/ComptrollerInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; abstract contract ComptrollerInterface { /// @notice Indicator that this is a Comptroller contract (for inspection) bool public constant isComptroller = true; /*** Assets You Are In ***/ function enterMarkets( address[] calldata cTokens ) external virtual returns (uint[] memory); function exitMarket(address cToken) external virtual returns (uint); /*** Policy Hooks ***/ function mintAllowed( address cToken, address minter, uint mintAmount ) external virtual returns (uint); function mintVerify( address cToken, address minter, uint mintAmount, uint mintTokens ) external virtual; function redeemAllowed( address cToken, address redeemer, uint redeemTokens ) external virtual returns (uint); function redeemVerify( address cToken, address redeemer, uint redeemAmount, uint redeemTokens ) external virtual; function borrowAllowed( address cToken, address borrower, uint borrowAmount ) external virtual returns (uint); function borrowVerify( address cToken, address borrower, uint borrowAmount ) external virtual; function repayBorrowAllowed( address cToken, address payer, address borrower, uint repayAmount ) external virtual returns (uint); function repayBorrowVerify( address cToken, address payer, address borrower, uint repayAmount, uint borrowerIndex ) external virtual; function liquidateBorrowAllowed( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount ) external virtual returns (uint); function liquidateBorrowVerify( address cTokenBorrowed, address cTokenCollateral, address liquidator, address borrower, uint repayAmount, uint seizeTokens ) external virtual; function seizeAllowed( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual returns (uint); function seizeVerify( address cTokenCollateral, address cTokenBorrowed, address liquidator, address borrower, uint seizeTokens ) external virtual; function transferAllowed( address cToken, address src, address dst, uint transferTokens ) external virtual returns (uint); function transferVerify( address cToken, address src, address dst, uint transferTokens ) external virtual; /*** Liquidity/Liquidation Calculations ***/ function liquidateCalculateSeizeTokens( address cTokenBorrowed, address cTokenCollateral, uint repayAmount ) external view virtual returns (uint, uint); }
contracts/EIP20Interface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title ERC 20 Token Standard Interface * https://eips.ethereum.org/EIPS/eip-20 */ interface EIP20Interface { function name() external view returns (string memory); function symbol() external view returns (string memory); function decimals() external view returns (uint8); /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transfer( address dst, uint256 amount ) external returns (bool success); /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer * @return success Whether or not the transfer succeeded */ function transferFrom( address src, address dst, uint256 amount ) external returns (bool success); /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved (-1 means infinite) * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent (-1 means infinite) */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/EIP20NonStandardInterface.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title EIP20NonStandardInterface * @dev Version of ERC20 with no return values for `transfer` and `transferFrom` * See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca */ interface EIP20NonStandardInterface { /** * @notice Get the total number of tokens in circulation * @return The supply of tokens */ function totalSupply() external view returns (uint256); /** * @notice Gets the balance of the specified address * @param owner The address from which the balance will be retrieved * @return balance The balance */ function balanceOf(address owner) external view returns (uint256 balance); /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transfer(address dst, uint256 amount) external; /// /// !!!!!!!!!!!!!! /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification /// !!!!!!!!!!!!!! /// /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param amount The number of tokens to transfer */ function transferFrom(address src, address dst, uint256 amount) external; /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param amount The number of tokens that are approved * @return success Whether or not the approval succeeded */ function approve( address spender, uint256 amount ) external returns (bool success); /** * @notice Get the current allowance from `owner` for `spender` * @param owner The address of the account which owns the tokens to be spent * @param spender The address of the account which may transfer tokens * @return remaining The number of tokens allowed to be spent */ function allowance( address owner, address spender ) external view returns (uint256 remaining); event Transfer(address indexed from, address indexed to, uint256 amount); event Approval( address indexed owner, address indexed spender, uint256 amount ); }
contracts/ErrorReporter.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; contract ComptrollerErrorReporter { enum Error { NO_ERROR, UNAUTHORIZED, COMPTROLLER_MISMATCH, INSUFFICIENT_SHORTFALL, INSUFFICIENT_LIQUIDITY, INVALID_CLOSE_FACTOR, INVALID_COLLATERAL_FACTOR, INVALID_LIQUIDATION_INCENTIVE, MARKET_NOT_ENTERED, // no longer possible MARKET_NOT_LISTED, MARKET_ALREADY_LISTED, MATH_ERROR, NONZERO_BORROW_BALANCE, PRICE_ERROR, REJECTION, SNAPSHOT_ERROR, TOO_MANY_ASSETS, TOO_MUCH_REPAY } enum FailureInfo { ACCEPT_ADMIN_PENDING_ADMIN_CHECK, ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK, EXIT_MARKET_BALANCE_OWED, EXIT_MARKET_REJECTION, SET_CLOSE_FACTOR_OWNER_CHECK, SET_CLOSE_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_OWNER_CHECK, SET_COLLATERAL_FACTOR_NO_EXISTS, SET_COLLATERAL_FACTOR_VALIDATION, SET_COLLATERAL_FACTOR_WITHOUT_PRICE, SET_IMPLEMENTATION_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_OWNER_CHECK, SET_LIQUIDATION_INCENTIVE_VALIDATION, SET_MAX_ASSETS_OWNER_CHECK, SET_PENDING_ADMIN_OWNER_CHECK, SET_PENDING_IMPLEMENTATION_OWNER_CHECK, SET_PRICE_ORACLE_OWNER_CHECK, SUPPORT_MARKET_EXISTS, SUPPORT_MARKET_OWNER_CHECK, SET_PAUSE_GUARDIAN_OWNER_CHECK } /** * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary * contract-specific code that enables us to report opaque error codes from upgradeable contracts. **/ event Failure(uint error, uint info, uint detail); /** * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator */ function fail(Error err, FailureInfo info) internal returns (uint) { emit Failure(uint(err), uint(info), 0); return uint(err); } /** * @dev use this when reporting an opaque error from an upgradeable collaborator contract */ function failOpaque( Error err, FailureInfo info, uint opaqueError ) internal returns (uint) { emit Failure(uint(err), uint(info), opaqueError); return uint(err); } } contract TokenErrorReporter { uint public constant NO_ERROR = 0; // support legacy return codes error TransferComptrollerRejection(uint256 errorCode); error TransferNotAllowed(); error TransferNotEnough(); error TransferTooMuch(); error MintComptrollerRejection(uint256 errorCode); error MintFreshnessCheck(); error RedeemComptrollerRejection(uint256 errorCode); error RedeemFreshnessCheck(); error RedeemTransferOutNotPossible(); error BorrowComptrollerRejection(uint256 errorCode); error BorrowFreshnessCheck(); error BorrowCashNotAvailable(); error RepayBorrowComptrollerRejection(uint256 errorCode); error RepayBorrowFreshnessCheck(); error LiquidateComptrollerRejection(uint256 errorCode); error LiquidateFreshnessCheck(); error LiquidateCollateralFreshnessCheck(); error LiquidateAccrueBorrowInterestFailed(uint256 errorCode); error LiquidateAccrueCollateralInterestFailed(uint256 errorCode); error LiquidateLiquidatorIsBorrower(); error LiquidateCloseAmountIsZero(); error LiquidateCloseAmountIsUintMax(); error LiquidateRepayBorrowFreshFailed(uint256 errorCode); error LiquidateSeizeComptrollerRejection(uint256 errorCode); error LiquidateSeizeLiquidatorIsBorrower(); error AcceptAdminPendingAdminCheck(); error SetComptrollerOwnerCheck(); error SetPendingAdminOwnerCheck(); error SetReserveFactorAdminCheck(); error SetReserveFactorFreshCheck(); error SetReserveFactorBoundsCheck(); error AddReservesFactorFreshCheck(uint256 actualAddAmount); error SetReserveGuardianOwnerCheck(); error ReduceReservesAdminCheck(); error ReduceReservesFreshCheck(); error ReduceReservesCashNotAvailable(); error ReduceReservesCashValidation(); error SetInterestRateModelOwnerCheck(); error SetInterestRateModelFreshCheck(); }
contracts/ExponentialNoError.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Exponential module for storing fixed-precision decimals * @author Compound * @notice Exp is a struct which stores decimals with a fixed precision of 18 decimal places. * Thus, if we wanted to store the 5.1, mantissa would store 5.1e18. That is: * `Exp({mantissa: 5100000000000000000})`. */ contract ExponentialNoError { uint constant expScale = 1e18; uint constant doubleScale = 1e36; uint constant halfExpScale = expScale / 2; uint constant mantissaOne = expScale; struct Exp { uint mantissa; } struct Double { uint mantissa; } /** * @dev Truncates the given exp to a whole number value. * For example, truncate(Exp{mantissa: 15 * expScale}) = 15 */ function truncate(Exp memory exp) internal pure returns (uint) { // Note: We are not using careful math here as we're performing a division that cannot fail return exp.mantissa / expScale; } /** * @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer. */ function mul_ScalarTruncate( Exp memory a, uint scalar ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return truncate(product); } /** * @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer. */ function mul_ScalarTruncateAddUInt( Exp memory a, uint scalar, uint addend ) internal pure returns (uint) { Exp memory product = mul_(a, scalar); return add_(truncate(product), addend); } /** * @dev Checks if first Exp is less than second Exp. */ function lessThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa < right.mantissa; } /** * @dev Checks if left Exp <= right Exp. */ function lessThanOrEqualExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa <= right.mantissa; } /** * @dev Checks if left Exp > right Exp. */ function greaterThanExp( Exp memory left, Exp memory right ) internal pure returns (bool) { return left.mantissa > right.mantissa; } /** * @dev returns true if Exp is exactly zero */ function isZeroExp(Exp memory value) internal pure returns (bool) { return value.mantissa == 0; } function safe224( uint n, string memory errorMessage ) internal pure returns (uint224) { require(n < 2 ** 224, errorMessage); return uint224(n); } function safe32( uint n, string memory errorMessage ) internal pure returns (uint32) { require(n < 2 ** 32, errorMessage); return uint32(n); } function add_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: add_(a.mantissa, b.mantissa)}); } function add_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: add_(a.mantissa, b.mantissa)}); } function add_(uint a, uint b) internal pure returns (uint) { return a + b; } function sub_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: sub_(a.mantissa, b.mantissa)}); } function sub_(uint a, uint b) internal pure returns (uint) { return a - b; } function mul_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale}); } function mul_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Exp memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / expScale; } function mul_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale}); } function mul_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: mul_(a.mantissa, b)}); } function mul_(uint a, Double memory b) internal pure returns (uint) { return mul_(a, b.mantissa) / doubleScale; } function mul_(uint a, uint b) internal pure returns (uint) { return a * b; } function div_( Exp memory a, Exp memory b ) internal pure returns (Exp memory) { return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)}); } function div_(Exp memory a, uint b) internal pure returns (Exp memory) { return Exp({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Exp memory b) internal pure returns (uint) { return div_(mul_(a, expScale), b.mantissa); } function div_( Double memory a, Double memory b ) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)}); } function div_( Double memory a, uint b ) internal pure returns (Double memory) { return Double({mantissa: div_(a.mantissa, b)}); } function div_(uint a, Double memory b) internal pure returns (uint) { return div_(mul_(a, doubleScale), b.mantissa); } function div_(uint a, uint b) internal pure returns (uint) { return a / b; } function fraction(uint a, uint b) internal pure returns (Double memory) { return Double({mantissa: div_(mul_(a, doubleScale), b)}); } }
contracts/InterestRateModel.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; /** * @title Compound's InterestRateModel Interface * @author Compound */ abstract contract InterestRateModel { /// @notice Indicator that this is an InterestRateModel contract (for inspection) bool public constant isInterestRateModel = true; /** * @notice Calculates the current borrow interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @return The borrow rate per block (as a percentage, and scaled by 1e18) */ function getBorrowRate( uint cash, uint borrows, uint reserves ) external view virtual returns (uint); /** * @notice Calculates the current supply interest rate per block * @param cash The total amount of cash the market has * @param borrows The total amount of borrows the market has outstanding * @param reserves The total amount of reserves the market has * @param reserveFactorMantissa The current reserve factor the market has * @return The supply rate per block (as a percentage, and scaled by 1e18) */ function getSupplyRate( uint cash, uint borrows, uint reserves, uint reserveFactorMantissa ) external view virtual returns (uint); }
contracts/PriceOracle.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "./CToken.sol"; abstract contract PriceOracle { /// @notice Indicator that this is a PriceOracle contract (for inspection) bool public constant isPriceOracle = true; /** * @notice Get the underlying price of a cToken asset * @param cToken The cToken to get the underlying price of * @return The underlying asset price mantissa (scaled by 1e18). * Zero means the price is unavailable. */ function getUnderlyingPrice( CToken cToken ) external view virtual returns (uint); }
contracts/RewardDistributor.sol
// SPDX-License-Identifier: BSD-3-Clause pragma solidity ^0.8.10; import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol"; import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import "./CTokenInterfaces.sol"; import "./EIP20Interface.sol"; import "./ExponentialNoError.sol"; struct RewardMarketState { /// @notice The supply speed for each market uint256 supplySpeed; /// @notice The supply index for each market uint256 supplyIndex; /// @notice The last tick that Reward accrued for supply uint256 supplyTick; /// @notice The borrow speed for each market uint256 borrowSpeed; /// @notice The borrow index for each market uint256 borrowIndex; /// @notice The last tick that Reward accrued for borrow uint256 borrowTick; } struct RewardAccountState { /// @notice The supply index for each market as of the last time the account accrued Reward mapping(address => uint256) supplierIndex; /// @notice The borrow index for each market as of the last time the account accrued Reward mapping(address => uint256) borrowerIndex; /// @notice Accrued Reward but not yet transferred uint256 rewardAccrued; } /** * @title Reward Distributor (version 1) * @author Sonne Finance * @notice This contract is used to distribute rewards to users for supplying and borrowing assets. * Each supply and borrow changing action from comptroller will trigger index update for each reward token. */ contract RewardDistributor is Initializable, OwnableUpgradeable, ExponentialNoError { event RewardAccrued( address indexed rewardToken, address indexed user, uint256 amount ); event RewardDistributed( address indexed rewardToken, address indexed user, uint256 amount ); event SupplySpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 supplySpeed ); event BorrowSpeedUpdated( address indexed rewardToken, address indexed cToken, uint256 borrowSpeed ); /// @notice The initial reward index for a market uint256 public constant rewardInitialIndex = 1e36; /// @notice The comptroller that rewards are distributed to address public comptroller; /// @notice The Reward state for each reward token for each market mapping(address => mapping(address => RewardMarketState)) public rewardMarketState; /// @notice The Reward state for each reward token for each account mapping(address => mapping(address => RewardAccountState)) public rewardAccountState; /// @notice Added reward tokens address[] public rewardTokens; /// @notice Flag to check if reward token added before mapping(address => bool) public rewardTokenExists; modifier onlyComptroller() { require( msg.sender == comptroller, "RewardDistributor: only comptroller can call this function" ); _; } function initialize(address comptroller_) public initializer { __Ownable_init(); comptroller = comptroller_; } function _whitelistToken(address rewardToken_) public onlyOwner { require( rewardToken_ != address(0), "RewardDistributor: reward token cannot be zero address" ); require( !rewardTokenExists[rewardToken_], "RewardDistributor: reward token already exists" ); rewardTokens.push(rewardToken_); rewardTokenExists[rewardToken_] = true; } function _updateRewardSpeeds( address rewardToken_, address[] memory cTokens, uint256[] memory supplySpeeds, uint256[] memory borrowSpeeds ) public onlyOwner { require( rewardTokenExists[rewardToken_], "RewardDistributor: reward token does not exist" ); require( cTokens.length == supplySpeeds.length, "RewardDistributor: supply speed array length mismatch" ); require( cTokens.length == borrowSpeeds.length, "RewardDistributor: borrow speed array length mismatch" ); for (uint256 i = 0; i < cTokens.length; i++) { updateRewardSpeedInternal( rewardToken_, cTokens[i], supplySpeeds[i], borrowSpeeds[i] ); } } function updateRewardSpeedInternal( address rewardToken, address cToken, uint256 supplySpeed, uint256 borrowSpeed ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; if (marketState.supplySpeed != supplySpeed) { if (marketState.supplyIndex == 0) { marketState.supplyIndex = rewardInitialIndex; } notifySupplyIndexInternal(rewardToken, cToken); marketState.supplySpeed = supplySpeed; emit SupplySpeedUpdated(rewardToken, cToken, supplySpeed); } if (marketState.borrowSpeed != borrowSpeed) { if (marketState.borrowIndex == 0) { marketState.borrowIndex = rewardInitialIndex; } notifyBorrowIndexInternal(rewardToken, cToken); marketState.borrowSpeed = borrowSpeed; emit BorrowSpeedUpdated(rewardToken, cToken, borrowSpeed); } } function notifySupplyIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplyIndexInternal(rewardTokens[i], cToken); } } function notifySupplyIndexInternal( address rewardToken, address cToken ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.supplyTick) { if (marketState.supplySpeed > 0) { uint256 deltaTick = tick - marketState.supplyTick; uint256 supplyTokens = CTokenInterface(cToken).totalSupply(); uint256 accrued = mul_(deltaTick, marketState.supplySpeed); Double memory ratio = supplyTokens > 0 ? fraction(accrued, supplyTokens) : Double({mantissa: 0}); marketState.supplyIndex = add_( Double({mantissa: marketState.supplyIndex}), ratio ).mantissa; } marketState.supplyTick = tick; } } function notifyBorrowIndex(address cToken) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowIndexInternal(rewardTokens[i], cToken); } } function notifyBorrowIndexInternal( address rewardToken, address cToken ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; uint256 tick = getTick(); if (tick > marketState.borrowTick) { if (marketState.borrowSpeed > 0) { uint256 deltaTick = tick - marketState.borrowTick; uint256 borrowAmount = div_( CTokenInterface(cToken).totalBorrows(), marketBorrowIndex ); uint256 accrued = mul_(deltaTick, marketState.borrowSpeed); Double memory ratio = borrowAmount > 0 ? fraction(accrued, borrowAmount) : Double({mantissa: 0}); marketState.borrowIndex = add_( Double({mantissa: marketState.borrowIndex}), ratio ).mantissa; } marketState.borrowTick = tick; } } function notifySupplier( address cToken, address supplier ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifySupplierInternal(rewardTokens[i], cToken, supplier); } } function notifySupplierInternal( address rewardToken, address cToken, address supplier ) internal { RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][supplier]; uint256 supplyIndex = marketState.supplyIndex; uint256 supplierIndex = accountState.supplierIndex[cToken]; // Update supplier's index to the current index since we are distributing accrued Reward accountState.supplierIndex[cToken] = supplyIndex; if (supplierIndex == 0 && supplyIndex >= rewardInitialIndex) { supplierIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per cToken accrued Double memory deltaIndex = Double({ mantissa: sub_(supplyIndex, supplierIndex) }); uint256 supplierTokens = CTokenInterface(cToken).balanceOf(supplier); // Calculate Reward accrued: cTokenAmount * accruedPerCToken uint256 supplierDelta = mul_(supplierTokens, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, supplierDelta ); } function notifyBorrower( address cToken, address borrower ) external onlyComptroller { for (uint256 i = 0; i < rewardTokens.length; i++) { notifyBorrowerInternal(rewardTokens[i], cToken, borrower); } } function notifyBorrowerInternal( address rewardToken, address cToken, address borrower ) internal { Exp memory marketBorrowIndex = Exp({ mantissa: CTokenInterface(cToken).borrowIndex() }); RewardMarketState storage marketState = rewardMarketState[rewardToken][ cToken ]; RewardAccountState storage accountState = rewardAccountState[ rewardToken ][borrower]; uint256 borrowIndex = marketState.borrowIndex; uint256 borrowerIndex = accountState.borrowerIndex[cToken]; // Update borrowers's index to the current index since we are distributing accrued Reward accountState.borrowerIndex[cToken] = borrowIndex; if (borrowerIndex == 0 && borrowIndex >= rewardInitialIndex) { // Covers the case where users borrowed tokens before the market's borrow state index was set. // Rewards the user with Reward accrued from the start of when borrower rewards were first // set for the market. borrowerIndex = rewardInitialIndex; } // Calculate change in the cumulative sum of the Reward per borrowed unit accrued Double memory deltaIndex = Double({ mantissa: sub_(borrowIndex, borrowerIndex) }); uint256 borrowerAmount = div_( CTokenInterface(cToken).borrowBalanceStored(borrower), marketBorrowIndex ); // Calculate Reward accrued: cTokenAmount * accruedPerBorrowedUnit uint256 borrowerDelta = mul_(borrowerAmount, deltaIndex); accountState.rewardAccrued = add_( accountState.rewardAccrued, borrowerDelta ); } function claim(address[] memory holders) public { for (uint256 i = 0; i < rewardTokens.length; i++) { claimInternal(rewardTokens[i], holders); } } function claimInternal( address rewardToken, address[] memory holders ) internal { for (uint256 j = 0; j < holders.length; j++) { RewardAccountState storage accountState = rewardAccountState[ rewardToken ][holders[j]]; accountState.rewardAccrued = grantRewardInternal( rewardToken, holders[j], accountState.rewardAccrued ); } } function getTick() public view returns (uint256) { return block.timestamp; } function _grantReward( address token, address user, uint256 amount ) public onlyOwner { require( rewardTokenExists[token], "RewardDistributor: grant reward token does not exist" ); grantRewardInternal(token, user, amount); } /** * @notice Transfer Reward to the user * @dev Note: If there is not enough Reward, we do not perform the transfer all. * @param user The address of the user to transfer Reward to * @param amount The amount of Reward to (possibly) transfer * @return The amount of Reward which was NOT transferred to the user */ function grantRewardInternal( address token, address user, uint256 amount ) internal returns (uint256) { uint256 remaining = EIP20Interface(token).balanceOf(address(this)); if (amount > 0 && amount <= remaining) { EIP20Interface(token).transfer(user, amount); return 0; } return amount; } /** Getters */ function getRewardTokens() public view returns (address[] memory) { return rewardTokens; } }
Contract ABI
[{"type":"function","stateMutability":"nonpayable","outputs":[{"type":"address[]","name":"rewardTokens","internalType":"address[]"},{"type":"uint256[]","name":"accrued","internalType":"uint256[]"}],"name":"rewardsAccrued","inputs":[{"type":"address","name":"comptroller","internalType":"contract ComptrollerLensInterface"},{"type":"address","name":"account","internalType":"address"}]}]
Contract Creation Code
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Deployed ByteCode
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