Contract Source Code:
// 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_,
uint 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
uint 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, uint tokens) internal returns (uint) {
/* Fail if transfer not allowed */
uint 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 */
uint startingAllowance = 0;
if (spender == src) {
startingAllowance = type(uint).max;
} else {
startingAllowance = transferAllowances[src][spender];
}
/* Do the calculations, checking for {under,over}flow */
uint allowanceNew = startingAllowance - tokens;
uint srcTokensNew = accountTokens[src] - tokens;
uint 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(uint).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) override external 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) override external 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) override external 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) override external view 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) override external view 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) override external returns (uint) {
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) override external view returns (uint, uint, uint, uint) {
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() virtual internal view returns (uint) {
return block.number;
}
/**
* @notice Returns the current per-block borrow interest rate for this cToken
* @return The borrow interest rate per block, scaled by 1e18
*/
function borrowRatePerBlock() override external view returns (uint) {
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() override external view returns (uint) {
return interestRateModel.getSupplyRate(getCashPrior(), totalBorrows, totalReserves, reserveFactorMantissa);
}
/**
* @notice Returns the current total borrows plus accrued interest
* @return The total borrows with interest
*/
function totalBorrowsCurrent() override external nonReentrant returns (uint) {
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) override external nonReentrant returns (uint) {
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) override public view returns (uint) {
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 (uint) {
/* 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
*/
uint 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() override public nonReentrant returns (uint) {
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() override public view returns (uint) {
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() virtual internal view returns (uint) {
uint _totalSupply = totalSupply;
if (_totalSupply == 0) {
/*
* If there are no tokens minted:
* exchangeRate = initialExchangeRate
*/
return initialExchangeRateMantissa;
} else {
/*
* Otherwise:
* exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply
*/
uint totalCash = getCashPrior();
uint cashPlusBorrowsMinusReserves = totalCash + totalBorrows - totalReserves;
uint 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() override external view returns (uint) {
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() virtual override public returns (uint) {
/* Remember the initial block number */
uint currentBlockNumber = getBlockNumber();
uint accrualBlockNumberPrior = accrualBlockNumber;
/* Short-circuit accumulating 0 interest */
if (accrualBlockNumberPrior == currentBlockNumber) {
return NO_ERROR;
}
/* Read the previous values out of storage */
uint cashPrior = getCashPrior();
uint borrowsPrior = totalBorrows;
uint reservesPrior = totalReserves;
uint borrowIndexPrior = borrowIndex;
/* Calculate the current borrow interest rate */
uint borrowRateMantissa = interestRateModel.getBorrowRate(cashPrior, borrowsPrior, reservesPrior);
require(borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high");
/* Calculate the number of blocks elapsed since the last accrual */
uint 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);
uint interestAccumulated = mul_ScalarTruncate(simpleInterestFactor, borrowsPrior);
uint totalBorrowsNew = interestAccumulated + borrowsPrior;
uint totalReservesNew = mul_ScalarTruncateAddUInt(Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior);
uint 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(uint 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, uint mintAmount) internal {
/* Fail if mint not allowed */
uint 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.
*/
uint actualMintAmount = doTransferIn(minter, mintAmount);
/*
* We get the current exchange rate and calculate the number of cTokens to be minted:
* mintTokens = actualMintAmount / exchangeRate
*/
uint 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 */
// unused function
// 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(uint 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(uint 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, uint redeemTokensIn, uint 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() });
uint redeemTokens;
uint 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 */
uint 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(uint 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, uint borrowAmount) internal {
/* Fail if borrow not allowed */
uint 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
*/
uint accountBorrowsPrev = borrowBalanceStoredInternal(borrower);
uint accountBorrowsNew = accountBorrowsPrev + borrowAmount;
uint 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(uint 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, uint 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, uint repayAmount) internal returns (uint) {
/* Fail if repayBorrow not allowed */
uint 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 */
uint accountBorrowsPrev = borrowBalanceStoredInternal(borrower);
/* If repayAmount == -1, repayAmount = accountBorrows */
uint repayAmountFinal = repayAmount == type(uint).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.
*/
uint actualRepayAmount = doTransferIn(payer, repayAmountFinal);
/*
* We calculate the new borrower and total borrow balances, failing on underflow:
* accountBorrowsNew = accountBorrows - actualRepayAmount
* totalBorrowsNew = totalBorrows - actualRepayAmount
*/
uint accountBorrowsNew = accountBorrowsPrev - actualRepayAmount;
uint 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, uint repayAmount, CTokenInterface cTokenCollateral) internal nonReentrant {
accrueInterest();
uint 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, uint repayAmount, CTokenInterface cTokenCollateral) internal {
/* Fail if liquidate not allowed */
uint 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(uint).max) {
revert LiquidateCloseAmountIsUintMax();
}
/* Fail if repayBorrow fails */
uint actualRepayAmount = repayBorrowFresh(liquidator, borrower, repayAmount);
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/* We calculate the number of collateral tokens that will be seized */
(uint amountSeizeError, uint 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, uint seizeTokens) override external nonReentrant returns (uint) {
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, uint seizeTokens) internal {
/* Fail if seize not allowed */
uint 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
*/
uint protocolSeizeTokens = mul_(seizeTokens, Exp({mantissa: protocolSeizeShareMantissa}));
uint liquidatorSeizeTokens = seizeTokens - protocolSeizeTokens;
Exp memory exchangeRate = Exp({mantissa: exchangeRateStoredInternal()});
uint protocolSeizeAmount = mul_ScalarTruncate(exchangeRate, protocolSeizeTokens);
uint 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) override external returns (uint) {
// 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() override external returns (uint) {
// 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) override public returns (uint) {
// 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(uint newReserveFactorMantissa) override external nonReentrant returns (uint) {
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(uint newReserveFactorMantissa) internal returns (uint) {
// 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();
}
uint 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(uint addAmount) internal nonReentrant returns (uint) {
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(uint addAmount) internal returns (uint, uint) {
// totalReserves + actualAddAmount
uint totalReservesNew;
uint 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 Accrues interest and reduces all reserves by transferring to treasury
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _reduceReserves() override external nonReentrant returns (uint) {
accrueInterest();
// _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to.
uint reduceAmount = totalReserves;
return _reduceReservesFresh(reduceAmount);
}
/**
* @notice Reduces reserves by transferring to treasury
* @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(uint reduceAmount) internal returns (uint) {
// totalReserves - reduceAmount
uint totalReservesNew;
// Check caller is treasury
if (msg.sender != IComptroller(address(comptroller)).treasury()) {
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(IComptroller(address(comptroller)).treasury()), 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) override public returns (uint) {
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 (uint) {
// 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() virtual internal view returns (uint);
/**
* @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, uint amount) virtual internal returns (uint);
/**
* @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, uint amount) virtual internal;
/*** 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
}
}
// 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 = 0.0005e16;
// 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%
}
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 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) virtual external returns (bool);
function transferFrom(address src, address dst, uint amount) virtual external returns (bool);
function approve(address spender, uint amount) virtual external returns (bool);
function allowance(address owner, address spender) virtual external view returns (uint);
function balanceOf(address owner) virtual external view returns (uint);
function balanceOfUnderlying(address owner) virtual external returns (uint);
function getAccountSnapshot(address account) virtual external view returns (uint, uint, uint, uint);
function borrowRatePerBlock() virtual external view returns (uint);
function supplyRatePerBlock() virtual external view returns (uint);
function totalBorrowsCurrent() virtual external returns (uint);
function borrowBalanceCurrent(address account) virtual external returns (uint);
function borrowBalanceStored(address account) virtual external view returns (uint);
function exchangeRateCurrent() virtual external returns (uint);
function exchangeRateStored() virtual external view returns (uint);
function getCash() virtual external view returns (uint);
function accrueInterest() virtual external returns (uint);
function seize(address liquidator, address borrower, uint seizeTokens) virtual external returns (uint);
/*** Admin Functions ***/
function _setPendingAdmin(address payable newPendingAdmin) virtual external returns (uint);
function _acceptAdmin() virtual external returns (uint);
function _setComptroller(ComptrollerInterface newComptroller) virtual external returns (uint);
function _setReserveFactor(uint newReserveFactorMantissa) virtual external returns (uint);
function _reduceReserves() virtual external returns (uint);
function _setInterestRateModel(InterestRateModel newInterestRateModel) virtual external returns (uint);
}
contract CErc20Storage {
/**
* @notice Underlying asset for this CToken
*/
address public underlying;
}
abstract contract CErc20Interface is CErc20Storage {
/*** User Interface ***/
function mint(uint mintAmount) virtual external returns (uint);
function redeem(uint redeemTokens) virtual external returns (uint);
function redeemUnderlying(uint redeemAmount) virtual external returns (uint);
function borrow(uint borrowAmount) virtual external returns (uint);
function repayBorrow(uint repayAmount) virtual external returns (uint);
function repayBorrowBehalf(address borrower, uint repayAmount) virtual external returns (uint);
function liquidateBorrow(address borrower, uint repayAmount, CTokenInterface cTokenCollateral) virtual external returns (uint);
function sweepToken(EIP20NonStandardInterface token) virtual external;
/*** Admin Functions ***/
function _addReserves(uint addAmount) virtual external 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) virtual external;
}
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) virtual external;
/**
* @notice Called by the delegator on a delegate to forfeit its responsibility
*/
function _resignImplementation() virtual external;
}
// 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) virtual external returns (uint[] memory);
function exitMarket(address cToken) virtual external returns (uint);
/*** Policy Hooks ***/
function mintAllowed(address cToken, address minter, uint mintAmount) virtual external returns (uint);
function mintVerify(address cToken, address minter, uint mintAmount, uint mintTokens) virtual external;
function redeemAllowed(address cToken, address redeemer, uint redeemTokens) virtual external returns (uint);
function redeemVerify(address cToken, address redeemer, uint redeemAmount, uint redeemTokens) virtual external;
function borrowAllowed(address cToken, address borrower, uint borrowAmount) virtual external returns (uint);
function borrowVerify(address cToken, address borrower, uint borrowAmount) virtual external;
function repayBorrowAllowed(
address cToken,
address payer,
address borrower,
uint repayAmount) virtual external returns (uint);
function repayBorrowVerify(
address cToken,
address payer,
address borrower,
uint repayAmount,
uint borrowerIndex) virtual external;
function liquidateBorrowAllowed(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint repayAmount) virtual external returns (uint);
function liquidateBorrowVerify(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint repayAmount,
uint seizeTokens) virtual external;
function seizeAllowed(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) virtual external returns (uint);
function seizeVerify(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) virtual external;
function transferAllowed(address cToken, address src, address dst, uint transferTokens) virtual external returns (uint);
function transferVerify(address cToken, address src, address dst, uint transferTokens) virtual external;
/*** Liquidity/Liquidation Calculations ***/
function liquidateCalculateSeizeTokens(
address cTokenBorrowed,
address cTokenCollateral,
uint repayAmount) virtual external view returns (uint, uint);
}
interface IComptroller {
// function liquidationIncentiveMantissa() external view returns (uint);
/*** Treasury ***/
function treasury() external view returns (address);
function gNFT() external view returns (address);
}
// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;
import "./CToken.sol";
import "./PriceOracle.sol";
contract UnitrollerAdminStorage {
/**
* @notice Administrator for this contract
*/
address public admin;
/**
* @notice Pending administrator for this contract
*/
address public pendingAdmin;
/**
* @notice Active brains of Unitroller
*/
address public comptrollerImplementation;
/**
* @notice Pending brains of Unitroller
*/
address public pendingComptrollerImplementation;
}
contract ComptrollerV1Storage is UnitrollerAdminStorage {
/**
* @notice Oracle which gives the price of any given asset
*/
PriceOracle public oracle;
/**
* @notice Multiplier used to calculate the maximum repayAmount when liquidating a borrow
*/
uint public closeFactorMantissa;
/**
* @notice Multiplier representing the discount on collateral that a liquidator receives
*/
uint public liquidationIncentiveMantissa;
/**
* @notice Max number of assets a single account can participate in (borrow or use as collateral)
*/
uint public maxAssets;
/**
* @notice Per-account mapping of "assets you are in", capped by maxAssets
*/
mapping(address => CToken[]) public accountAssets;
}
contract ComptrollerV2Storage is ComptrollerV1Storage {
struct Market {
// Whether or not this market is listed
bool isListed;
// Multiplier representing the most one can borrow against their collateral in this market.
// For instance, 0.9 to allow borrowing 90% of collateral value.
// Must be between 0 and 1, and stored as a mantissa.
uint collateralFactorMantissa;
// Per-market mapping of "accounts in this asset"
mapping(address => bool) accountMembership;
// Whether or not this market receives COMP
bool isComped;
}
/**
* @notice Official mapping of cTokens -> Market metadata
* @dev Used e.g. to determine if a market is supported
*/
mapping(address => Market) public markets;
/**
* @notice The Pause Guardian can pause certain actions as a safety mechanism.
* Actions which allow users to remove their own assets cannot be paused.
* Liquidation / seizing / transfer can only be paused globally, not by market.
*/
address public pauseGuardian;
bool public _mintGuardianPaused;
bool public _borrowGuardianPaused;
bool public transferGuardianPaused;
bool public seizeGuardianPaused;
mapping(address => bool) public mintGuardianPaused;
mapping(address => bool) public borrowGuardianPaused;
}
contract ComptrollerV3Storage is ComptrollerV2Storage {
struct CompMarketState {
// The market's last updated compBorrowIndex or compSupplyIndex
uint224 index;
// The block number the index was last updated at
uint32 block;
}
/// @notice A list of all markets
CToken[] public allMarkets;
/// @notice The rate at which the flywheel distributes COMP, per block
uint public compRate;
/// @notice The portion of compRate that each market currently receives
mapping(address => uint) public compSpeeds;
/// @notice The COMP market supply state for each market
mapping(address => CompMarketState) public compSupplyState;
/// @notice The COMP market borrow state for each market
mapping(address => CompMarketState) public compBorrowState;
/// @notice The COMP borrow index for each market for each supplier as of the last time they accrued COMP
mapping(address => mapping(address => uint)) public compSupplierIndex;
/// @notice The COMP borrow index for each market for each borrower as of the last time they accrued COMP
mapping(address => mapping(address => uint)) public compBorrowerIndex;
/// @notice The COMP accrued but not yet transferred to each user
mapping(address => uint) public compAccrued;
}
contract ComptrollerV4Storage is ComptrollerV3Storage {
// @notice The borrowCapGuardian can set borrowCaps to any number for any market. Lowering the borrow cap could disable borrowing on the given market.
address public borrowCapGuardian;
// @notice Borrow caps enforced by borrowAllowed for each cToken address. Defaults to zero which corresponds to unlimited borrowing.
mapping(address => uint) public borrowCaps;
}
contract ComptrollerV5Storage is ComptrollerV4Storage {
/// @notice The portion of COMP that each contributor receives per block
mapping(address => uint) public compContributorSpeeds;
/// @notice Last block at which a contributor's COMP rewards have been allocated
mapping(address => uint) public lastContributorBlock;
}
contract ComptrollerV6Storage is ComptrollerV5Storage {
/// @notice The rate at which comp is distributed to the corresponding borrow market (per block)
mapping(address => uint) public compBorrowSpeeds;
/// @notice The rate at which comp is distributed to the corresponding supply market (per block)
mapping(address => uint) public compSupplySpeeds;
}
contract ComptrollerV7Storage is ComptrollerV6Storage {
/// @notice Accounting storage mapping account addresses to how much COMP they owe the protocol.
mapping(address => uint) public compReceivable;
/// @notice The address of the treasury which collects and distributes reserves
address public treasury;
/// @notice The address of the governance gNFT token
address public gNFT;
/// @notice The address of the Tonpound Participation Index token
address public compAddress;
}
// 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);
}
// 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);
}
// 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 ReduceReservesAdminCheck();
error ReduceReservesFreshCheck();
error ReduceReservesCashNotAvailable();
error ReduceReservesCashValidation();
error SetInterestRateModelOwnerCheck();
error SetInterestRateModelFreshCheck();
}
// 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) pure internal 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) pure internal 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) pure internal 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) pure internal returns (bool) {
return left.mantissa < right.mantissa;
}
/**
* @dev Checks if left Exp <= right Exp.
*/
function lessThanOrEqualExp(Exp memory left, Exp memory right) pure internal returns (bool) {
return left.mantissa <= right.mantissa;
}
/**
* @dev Checks if left Exp > right Exp.
*/
function greaterThanExp(Exp memory left, Exp memory right) pure internal returns (bool) {
return left.mantissa > right.mantissa;
}
/**
* @dev returns true if Exp is exactly zero
*/
function isZeroExp(Exp memory value) pure internal returns (bool) {
return value.mantissa == 0;
}
function safe224(uint n, string memory errorMessage) pure internal returns (uint224) {
require(n < 2**224, errorMessage);
return uint224(n);
}
function safe32(uint n, string memory errorMessage) pure internal returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
function add_(Exp memory a, Exp memory b) pure internal returns (Exp memory) {
return Exp({mantissa: add_(a.mantissa, b.mantissa)});
}
function add_(Double memory a, Double memory b) pure internal returns (Double memory) {
return Double({mantissa: add_(a.mantissa, b.mantissa)});
}
function add_(uint a, uint b) pure internal returns (uint) {
return a + b;
}
function sub_(Exp memory a, Exp memory b) pure internal returns (Exp memory) {
return Exp({mantissa: sub_(a.mantissa, b.mantissa)});
}
function sub_(Double memory a, Double memory b) pure internal returns (Double memory) {
return Double({mantissa: sub_(a.mantissa, b.mantissa)});
}
function sub_(uint a, uint b) pure internal returns (uint) {
return a - b;
}
function mul_(Exp memory a, Exp memory b) pure internal returns (Exp memory) {
return Exp({mantissa: mul_(a.mantissa, b.mantissa) / expScale});
}
function mul_(Exp memory a, uint b) pure internal returns (Exp memory) {
return Exp({mantissa: mul_(a.mantissa, b)});
}
function mul_(uint a, Exp memory b) pure internal returns (uint) {
return mul_(a, b.mantissa) / expScale;
}
function mul_(Double memory a, Double memory b) pure internal returns (Double memory) {
return Double({mantissa: mul_(a.mantissa, b.mantissa) / doubleScale});
}
function mul_(Double memory a, uint b) pure internal returns (Double memory) {
return Double({mantissa: mul_(a.mantissa, b)});
}
function mul_(uint a, Double memory b) pure internal returns (uint) {
return mul_(a, b.mantissa) / doubleScale;
}
function mul_(uint a, uint b) pure internal returns (uint) {
return a * b;
}
function div_(Exp memory a, Exp memory b) pure internal returns (Exp memory) {
return Exp({mantissa: div_(mul_(a.mantissa, expScale), b.mantissa)});
}
function div_(Exp memory a, uint b) pure internal returns (Exp memory) {
return Exp({mantissa: div_(a.mantissa, b)});
}
function div_(uint a, Exp memory b) pure internal returns (uint) {
return div_(mul_(a, expScale), b.mantissa);
}
function div_(Double memory a, Double memory b) pure internal returns (Double memory) {
return Double({mantissa: div_(mul_(a.mantissa, doubleScale), b.mantissa)});
}
function div_(Double memory a, uint b) pure internal returns (Double memory) {
return Double({mantissa: div_(a.mantissa, b)});
}
function div_(uint a, Double memory b) pure internal returns (uint) {
return div_(mul_(a, doubleScale), b.mantissa);
}
function div_(uint a, uint b) pure internal returns (uint) {
return a / b;
}
function fraction(uint a, uint b) pure internal returns (Double memory) {
return Double({mantissa: div_(mul_(a, doubleScale), b)});
}
}
// 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) virtual external view 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) virtual external view returns (uint);
}
// 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) virtual external view returns (uint);
}
// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;
import "./ErrorReporter.sol";
import "./ComptrollerStorage.sol";
/**
* @title ComptrollerCore
* @dev Storage for the comptroller is at this address, while execution is delegated to the `comptrollerImplementation`.
* CTokens should reference this contract as their comptroller.
*/
contract Unitroller is UnitrollerAdminStorage, ComptrollerErrorReporter {
/**
* @notice Emitted when pendingComptrollerImplementation is changed
*/
event NewPendingImplementation(address oldPendingImplementation, address newPendingImplementation);
/**
* @notice Emitted when pendingComptrollerImplementation is accepted, which means comptroller implementation is updated
*/
event NewImplementation(address oldImplementation, address newImplementation);
/**
* @notice Emitted when pendingAdmin is changed
*/
event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);
/**
* @notice Emitted when pendingAdmin is accepted, which means admin is updated
*/
event NewAdmin(address oldAdmin, address newAdmin);
constructor() public {
// Set admin to caller
admin = msg.sender;
}
/*** Admin Functions ***/
function _setPendingImplementation(address newPendingImplementation) public returns (uint) {
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_PENDING_IMPLEMENTATION_OWNER_CHECK);
}
address oldPendingImplementation = pendingComptrollerImplementation;
pendingComptrollerImplementation = newPendingImplementation;
emit NewPendingImplementation(oldPendingImplementation, pendingComptrollerImplementation);
return uint(Error.NO_ERROR);
}
/**
* @notice Accepts new implementation of comptroller. msg.sender must be pendingImplementation
* @dev Admin function for new implementation to accept it's role as implementation
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _acceptImplementation() public returns (uint) {
// Check caller is pendingImplementation and pendingImplementation ≠ address(0)
if (msg.sender != pendingComptrollerImplementation || pendingComptrollerImplementation == address(0)) {
return fail(Error.UNAUTHORIZED, FailureInfo.ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK);
}
// Save current values for inclusion in log
address oldImplementation = comptrollerImplementation;
address oldPendingImplementation = pendingComptrollerImplementation;
comptrollerImplementation = pendingComptrollerImplementation;
pendingComptrollerImplementation = address(0);
emit NewImplementation(oldImplementation, comptrollerImplementation);
emit NewPendingImplementation(oldPendingImplementation, pendingComptrollerImplementation);
return uint(Error.NO_ERROR);
}
/**
* @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 newPendingAdmin) public returns (uint) {
// Check caller = admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_PENDING_ADMIN_OWNER_CHECK);
}
// 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 uint(Error.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() public returns (uint) {
// Check caller is pendingAdmin and pendingAdmin ≠ address(0)
if (msg.sender != pendingAdmin || msg.sender == address(0)) {
return fail(Error.UNAUTHORIZED, FailureInfo.ACCEPT_ADMIN_PENDING_ADMIN_CHECK);
}
// 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 = address(0);
emit NewAdmin(oldAdmin, admin);
emit NewPendingAdmin(oldPendingAdmin, pendingAdmin);
return uint(Error.NO_ERROR);
}
/**
* @dev Delegates execution to an implementation contract.
* It returns to the external caller whatever the implementation returns
* or forwards reverts.
*/
fallback() payable external {
// delegate all other functions to current implementation
(bool success, ) = comptrollerImplementation.delegatecall(msg.data);
assembly {
let free_mem_ptr := mload(0x40)
returndatacopy(free_mem_ptr, 0, returndatasize())
switch success
case 0 { revert(free_mem_ptr, returndatasize()) }
default { return(free_mem_ptr, returndatasize()) }
}
}
}