Contract Name:
Comptroller
Contract Source Code:
pragma solidity ^0.5.16;
/**
* @title Careful Math
* @author Compound
* @notice Derived from OpenZeppelin's SafeMath library
* https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/math/SafeMath.sol
*/
contract CarefulMath {
/**
* @dev Possible error codes that we can return
*/
enum MathError {
NO_ERROR,
DIVISION_BY_ZERO,
INTEGER_OVERFLOW,
INTEGER_UNDERFLOW
}
/**
* @dev Multiplies two numbers, returns an error on overflow.
*/
function mulUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (a == 0) {
return (MathError.NO_ERROR, 0);
}
uint c = a * b;
if (c / a != b) {
return (MathError.INTEGER_OVERFLOW, 0);
} else {
return (MathError.NO_ERROR, c);
}
}
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function divUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (b == 0) {
return (MathError.DIVISION_BY_ZERO, 0);
}
return (MathError.NO_ERROR, a / b);
}
/**
* @dev Subtracts two numbers, returns an error on overflow (i.e. if subtrahend is greater than minuend).
*/
function subUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (b <= a) {
return (MathError.NO_ERROR, a - b);
} else {
return (MathError.INTEGER_UNDERFLOW, 0);
}
}
/**
* @dev Adds two numbers, returns an error on overflow.
*/
function addUInt(uint a, uint b) internal pure returns (MathError, uint) {
uint c = a + b;
if (c >= a) {
return (MathError.NO_ERROR, c);
} else {
return (MathError.INTEGER_OVERFLOW, 0);
}
}
/**
* @dev add a and b and then subtract c
*/
function addThenSubUInt(uint a, uint b, uint c) internal pure returns (MathError, uint) {
(MathError err0, uint sum) = addUInt(a, b);
if (err0 != MathError.NO_ERROR) {
return (err0, 0);
}
return subUInt(sum, c);
}
}
pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;
contract Comp {
/// @notice EIP-20 token name for this token
string public constant name = "Cream";
/// @notice EIP-20 token symbol for this token
string public constant symbol = "CREAM";
/// @notice EIP-20 token decimals for this token
uint8 public constant decimals = 18;
/// @notice Total number of tokens in circulation
uint public constant totalSupply = 9000000e18; // 9 million Comp
/// @notice Allowance amounts on behalf of others
mapping (address => mapping (address => uint96)) internal allowances;
/// @notice Official record of token balances for each account
mapping (address => uint96) internal balances;
/// @notice A record of each accounts delegate
mapping (address => address) public delegates;
/// @notice A checkpoint for marking number of votes from a given block
struct Checkpoint {
uint32 fromBlock;
uint96 votes;
}
/// @notice A record of votes checkpoints for each account, by index
mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;
/// @notice The number of checkpoints for each account
mapping (address => uint32) public numCheckpoints;
/// @notice The EIP-712 typehash for the contract's domain
bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
/// @notice The EIP-712 typehash for the delegation struct used by the contract
bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");
/// @notice A record of states for signing / validating signatures
mapping (address => uint) public nonces;
/// @notice An event thats emitted when an account changes its delegate
event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
/// @notice An event thats emitted when a delegate account's vote balance changes
event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);
/// @notice The standard EIP-20 transfer event
event Transfer(address indexed from, address indexed to, uint256 amount);
/// @notice The standard EIP-20 approval event
event Approval(address indexed owner, address indexed spender, uint256 amount);
/**
* @notice Construct a new Comp token
* @param account The initial account to grant all the tokens
*/
constructor(address account) public {
balances[account] = uint96(totalSupply);
emit Transfer(address(0), account, totalSupply);
}
/**
* @notice Get the number of tokens `spender` is approved to spend on behalf of `account`
* @param account The address of the account holding the funds
* @param spender The address of the account spending the funds
* @return The number of tokens approved
*/
function allowance(address account, address spender) external view returns (uint) {
return allowances[account][spender];
}
/**
* @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 rawAmount The number of tokens that are approved (2^256-1 means infinite)
* @return Whether or not the approval succeeded
*/
function approve(address spender, uint rawAmount) external returns (bool) {
uint96 amount;
if (rawAmount == uint(-1)) {
amount = uint96(-1);
} else {
amount = safe96(rawAmount, "Comp::approve: amount exceeds 96 bits");
}
allowances[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}
/**
* @notice Get the number of tokens held by the `account`
* @param account The address of the account to get the balance of
* @return The number of tokens held
*/
function balanceOf(address account) external view returns (uint) {
return balances[account];
}
/**
* @notice Transfer `amount` tokens from `msg.sender` to `dst`
* @param dst The address of the destination account
* @param rawAmount The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transfer(address dst, uint rawAmount) external returns (bool) {
uint96 amount = safe96(rawAmount, "Comp::transfer: amount exceeds 96 bits");
_transferTokens(msg.sender, dst, amount);
return true;
}
/**
* @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 rawAmount The number of tokens to transfer
* @return Whether or not the transfer succeeded
*/
function transferFrom(address src, address dst, uint rawAmount) external returns (bool) {
address spender = msg.sender;
uint96 spenderAllowance = allowances[src][spender];
uint96 amount = safe96(rawAmount, "Comp::approve: amount exceeds 96 bits");
if (spender != src && spenderAllowance != uint96(-1)) {
uint96 newAllowance = sub96(spenderAllowance, amount, "Comp::transferFrom: transfer amount exceeds spender allowance");
allowances[src][spender] = newAllowance;
emit Approval(src, spender, newAllowance);
}
_transferTokens(src, dst, amount);
return true;
}
/**
* @notice Delegate votes from `msg.sender` to `delegatee`
* @param delegatee The address to delegate votes to
*/
function delegate(address delegatee) public {
return _delegate(msg.sender, delegatee);
}
/**
* @notice Delegates votes from signatory to `delegatee`
* @param delegatee The address to delegate votes to
* @param nonce The contract state required to match the signature
* @param expiry The time at which to expire the signature
* @param v The recovery byte of the signature
* @param r Half of the ECDSA signature pair
* @param s Half of the ECDSA signature pair
*/
function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) public {
bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this)));
bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
address signatory = ecrecover(digest, v, r, s);
require(signatory != address(0), "Comp::delegateBySig: invalid signature");
require(nonce == nonces[signatory]++, "Comp::delegateBySig: invalid nonce");
require(now <= expiry, "Comp::delegateBySig: signature expired");
return _delegate(signatory, delegatee);
}
/**
* @notice Gets the current votes balance for `account`
* @param account The address to get votes balance
* @return The number of current votes for `account`
*/
function getCurrentVotes(address account) external view returns (uint96) {
uint32 nCheckpoints = numCheckpoints[account];
return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
}
/**
* @notice Determine the prior number of votes for an account as of a block number
* @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
* @param account The address of the account to check
* @param blockNumber The block number to get the vote balance at
* @return The number of votes the account had as of the given block
*/
function getPriorVotes(address account, uint blockNumber) public view returns (uint96) {
require(blockNumber < block.number, "Comp::getPriorVotes: not yet determined");
uint32 nCheckpoints = numCheckpoints[account];
if (nCheckpoints == 0) {
return 0;
}
// First check most recent balance
if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
return checkpoints[account][nCheckpoints - 1].votes;
}
// Next check implicit zero balance
if (checkpoints[account][0].fromBlock > blockNumber) {
return 0;
}
uint32 lower = 0;
uint32 upper = nCheckpoints - 1;
while (upper > lower) {
uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
Checkpoint memory cp = checkpoints[account][center];
if (cp.fromBlock == blockNumber) {
return cp.votes;
} else if (cp.fromBlock < blockNumber) {
lower = center;
} else {
upper = center - 1;
}
}
return checkpoints[account][lower].votes;
}
function _delegate(address delegator, address delegatee) internal {
address currentDelegate = delegates[delegator];
uint96 delegatorBalance = balances[delegator];
delegates[delegator] = delegatee;
emit DelegateChanged(delegator, currentDelegate, delegatee);
_moveDelegates(currentDelegate, delegatee, delegatorBalance);
}
function _transferTokens(address src, address dst, uint96 amount) internal {
require(src != address(0), "Comp::_transferTokens: cannot transfer from the zero address");
require(dst != address(0), "Comp::_transferTokens: cannot transfer to the zero address");
balances[src] = sub96(balances[src], amount, "Comp::_transferTokens: transfer amount exceeds balance");
balances[dst] = add96(balances[dst], amount, "Comp::_transferTokens: transfer amount overflows");
emit Transfer(src, dst, amount);
_moveDelegates(delegates[src], delegates[dst], amount);
}
function _moveDelegates(address srcRep, address dstRep, uint96 amount) internal {
if (srcRep != dstRep && amount > 0) {
if (srcRep != address(0)) {
uint32 srcRepNum = numCheckpoints[srcRep];
uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
uint96 srcRepNew = sub96(srcRepOld, amount, "Comp::_moveVotes: vote amount underflows");
_writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
}
if (dstRep != address(0)) {
uint32 dstRepNum = numCheckpoints[dstRep];
uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
uint96 dstRepNew = add96(dstRepOld, amount, "Comp::_moveVotes: vote amount overflows");
_writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
}
}
}
function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint96 oldVotes, uint96 newVotes) internal {
uint32 blockNumber = safe32(block.number, "Comp::_writeCheckpoint: block number exceeds 32 bits");
if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
} else {
checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
numCheckpoints[delegatee] = nCheckpoints + 1;
}
emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
}
function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {
require(n < 2**32, errorMessage);
return uint32(n);
}
function safe96(uint n, string memory errorMessage) internal pure returns (uint96) {
require(n < 2**96, errorMessage);
return uint96(n);
}
function add96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
uint96 c = a + b;
require(c >= a, errorMessage);
return c;
}
function sub96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
require(b <= a, errorMessage);
return a - b;
}
function getChainId() internal pure returns (uint) {
uint256 chainId;
assembly { chainId := chainid() }
return chainId;
}
}
pragma solidity ^0.5.16;
import "./CToken.sol";
import "./ErrorReporter.sol";
import "./Exponential.sol";
import "./PriceOracle.sol";
import "./ComptrollerInterface.sol";
import "./ComptrollerStorage.sol";
import "./Unitroller.sol";
import "./Comp.sol";
/**
* @title Compound's Comptroller Contract
* @author Compound
*/
contract Comptroller is ComptrollerV3Storage, ComptrollerInterface, ComptrollerErrorReporter, Exponential {
/// @notice Emitted when an admin supports a market
event MarketListed(CToken cToken);
/// @notice Emitted when an account enters a market
event MarketEntered(CToken cToken, address account);
/// @notice Emitted when an account exits a market
event MarketExited(CToken cToken, address account);
/// @notice Emitted when close factor is changed by admin
event NewCloseFactor(uint oldCloseFactorMantissa, uint newCloseFactorMantissa);
/// @notice Emitted when a collateral factor is changed by admin
event NewCollateralFactor(CToken cToken, uint oldCollateralFactorMantissa, uint newCollateralFactorMantissa);
/// @notice Emitted when liquidation incentive is changed by admin
event NewLiquidationIncentive(uint oldLiquidationIncentiveMantissa, uint newLiquidationIncentiveMantissa);
/// @notice Emitted when maxAssets is changed by admin
event NewMaxAssets(uint oldMaxAssets, uint newMaxAssets);
/// @notice Emitted when price oracle is changed
event NewPriceOracle(PriceOracle oldPriceOracle, PriceOracle newPriceOracle);
/// @notice Emitted when pause guardian is changed
event NewPauseGuardian(address oldPauseGuardian, address newPauseGuardian);
/// @notice Emitted when an action is paused globally
event ActionPaused(string action, bool pauseState);
/// @notice Emitted when an action is paused on a market
event ActionPaused(CToken cToken, string action, bool pauseState);
/// @notice Emitted when market comped status is changed
event MarketComped(CToken cToken, bool isComped);
/// @notice Emitted when COMP rate is changed
event NewCompRate(uint oldCompRate, uint newCompRate);
/// @notice Emitted when a new COMP speed is calculated for a market
event CompSpeedUpdated(CToken indexed cToken, uint newSpeed);
/// @notice Emitted when COMP is distributed to a supplier
event DistributedSupplierComp(CToken indexed cToken, address indexed supplier, uint compDelta, uint compSupplyIndex);
/// @notice Emitted when COMP is distributed to a borrower
event DistributedBorrowerComp(CToken indexed cToken, address indexed borrower, uint compDelta, uint compBorrowIndex);
/// @notice The threshold above which the flywheel transfers COMP, in wei
uint public constant compClaimThreshold = 0.001e18;
/// @notice The initial COMP index for a market
uint224 public constant compInitialIndex = 1e36;
// closeFactorMantissa must be strictly greater than this value
uint internal constant closeFactorMinMantissa = 0.05e18; // 0.05
// closeFactorMantissa must not exceed this value
uint internal constant closeFactorMaxMantissa = 0.9e18; // 0.9
// No collateralFactorMantissa may exceed this value
uint internal constant collateralFactorMaxMantissa = 0.9e18; // 0.9
// liquidationIncentiveMantissa must be no less than this value
uint internal constant liquidationIncentiveMinMantissa = 1.0e18; // 1.0
// liquidationIncentiveMantissa must be no greater than this value
uint internal constant liquidationIncentiveMaxMantissa = 1.5e18; // 1.5
constructor() public {
admin = msg.sender;
}
/*** Assets You Are In ***/
/**
* @notice Returns the assets an account has entered
* @param account The address of the account to pull assets for
* @return A dynamic list with the assets the account has entered
*/
function getAssetsIn(address account) external view returns (CToken[] memory) {
CToken[] memory assetsIn = accountAssets[account];
return assetsIn;
}
/**
* @notice Returns whether the given account is entered in the given asset
* @param account The address of the account to check
* @param cToken The cToken to check
* @return True if the account is in the asset, otherwise false.
*/
function checkMembership(address account, CToken cToken) external view returns (bool) {
return markets[address(cToken)].accountMembership[account];
}
/**
* @notice Add assets to be included in account liquidity calculation
* @param cTokens The list of addresses of the cToken markets to be enabled
* @return Success indicator for whether each corresponding market was entered
*/
function enterMarkets(address[] memory cTokens) public returns (uint[] memory) {
uint len = cTokens.length;
uint[] memory results = new uint[](len);
for (uint i = 0; i < len; i++) {
CToken cToken = CToken(cTokens[i]);
results[i] = uint(addToMarketInternal(cToken, msg.sender));
}
return results;
}
/**
* @notice Add the market to the borrower's "assets in" for liquidity calculations
* @param cToken The market to enter
* @param borrower The address of the account to modify
* @return Success indicator for whether the market was entered
*/
function addToMarketInternal(CToken cToken, address borrower) internal returns (Error) {
Market storage marketToJoin = markets[address(cToken)];
if (!marketToJoin.isListed) {
// market is not listed, cannot join
return Error.MARKET_NOT_LISTED;
}
if (marketToJoin.accountMembership[borrower] == true) {
// already joined
return Error.NO_ERROR;
}
if (accountAssets[borrower].length >= maxAssets) {
// no space, cannot join
return Error.TOO_MANY_ASSETS;
}
// survived the gauntlet, add to list
// NOTE: we store these somewhat redundantly as a significant optimization
// this avoids having to iterate through the list for the most common use cases
// that is, only when we need to perform liquidity checks
// and not whenever we want to check if an account is in a particular market
marketToJoin.accountMembership[borrower] = true;
accountAssets[borrower].push(cToken);
emit MarketEntered(cToken, borrower);
return Error.NO_ERROR;
}
/**
* @notice Removes asset from sender's account liquidity calculation
* @dev Sender must not have an outstanding borrow balance in the asset,
* or be providing necessary collateral for an outstanding borrow.
* @param cTokenAddress The address of the asset to be removed
* @return Whether or not the account successfully exited the market
*/
function exitMarket(address cTokenAddress) external returns (uint) {
CToken cToken = CToken(cTokenAddress);
/* Get sender tokensHeld and amountOwed underlying from the cToken */
(uint oErr, uint tokensHeld, uint amountOwed, ) = cToken.getAccountSnapshot(msg.sender);
require(oErr == 0, "exitMarket: getAccountSnapshot failed"); // semi-opaque error code
/* Fail if the sender has a borrow balance */
if (amountOwed != 0) {
return fail(Error.NONZERO_BORROW_BALANCE, FailureInfo.EXIT_MARKET_BALANCE_OWED);
}
/* Fail if the sender is not permitted to redeem all of their tokens */
uint allowed = redeemAllowedInternal(cTokenAddress, msg.sender, tokensHeld);
if (allowed != 0) {
return failOpaque(Error.REJECTION, FailureInfo.EXIT_MARKET_REJECTION, allowed);
}
Market storage marketToExit = markets[address(cToken)];
/* Return true if the sender is not already ‘in’ the market */
if (!marketToExit.accountMembership[msg.sender]) {
return uint(Error.NO_ERROR);
}
/* Set cToken account membership to false */
delete marketToExit.accountMembership[msg.sender];
/* Delete cToken from the account’s list of assets */
// load into memory for faster iteration
CToken[] memory userAssetList = accountAssets[msg.sender];
uint len = userAssetList.length;
uint assetIndex = len;
for (uint i = 0; i < len; i++) {
if (userAssetList[i] == cToken) {
assetIndex = i;
break;
}
}
// We *must* have found the asset in the list or our redundant data structure is broken
assert(assetIndex < len);
// copy last item in list to location of item to be removed, reduce length by 1
CToken[] storage storedList = accountAssets[msg.sender];
storedList[assetIndex] = storedList[storedList.length - 1];
storedList.length--;
emit MarketExited(cToken, msg.sender);
return uint(Error.NO_ERROR);
}
/*** Policy Hooks ***/
/**
* @notice Checks if the account should be allowed to mint tokens in the given market
* @param cToken The market to verify the mint against
* @param minter The account which would get the minted tokens
* @param mintAmount The amount of underlying being supplied to the market in exchange for tokens
* @return 0 if the mint is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
*/
function mintAllowed(address cToken, address minter, uint mintAmount) external returns (uint) {
// Pausing is a very serious situation - we revert to sound the alarms
require(!mintGuardianPaused[cToken], "mint is paused");
// Shh - currently unused
minter;
mintAmount;
if (!markets[cToken].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
// Keep the flywheel moving
updateCompSupplyIndex(cToken);
distributeSupplierComp(cToken, minter, false);
return uint(Error.NO_ERROR);
}
/**
* @notice Validates mint and reverts on rejection. May emit logs.
* @param cToken Asset being minted
* @param minter The address minting the tokens
* @param actualMintAmount The amount of the underlying asset being minted
* @param mintTokens The number of tokens being minted
*/
function mintVerify(address cToken, address minter, uint actualMintAmount, uint mintTokens) external {
// Shh - currently unused
cToken;
minter;
actualMintAmount;
mintTokens;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/**
* @notice Checks if the account should be allowed to redeem tokens in the given market
* @param cToken The market to verify the redeem against
* @param redeemer The account which would redeem the tokens
* @param redeemTokens The number of cTokens to exchange for the underlying asset in the market
* @return 0 if the redeem is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
*/
function redeemAllowed(address cToken, address redeemer, uint redeemTokens) external returns (uint) {
uint allowed = redeemAllowedInternal(cToken, redeemer, redeemTokens);
if (allowed != uint(Error.NO_ERROR)) {
return allowed;
}
// Keep the flywheel moving
updateCompSupplyIndex(cToken);
distributeSupplierComp(cToken, redeemer, false);
return uint(Error.NO_ERROR);
}
function redeemAllowedInternal(address cToken, address redeemer, uint redeemTokens) internal view returns (uint) {
if (!markets[cToken].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
/* If the redeemer is not 'in' the market, then we can bypass the liquidity check */
if (!markets[cToken].accountMembership[redeemer]) {
return uint(Error.NO_ERROR);
}
/* Otherwise, perform a hypothetical liquidity check to guard against shortfall */
(Error err, , uint shortfall) = getHypotheticalAccountLiquidityInternal(redeemer, CToken(cToken), redeemTokens, 0);
if (err != Error.NO_ERROR) {
return uint(err);
}
if (shortfall > 0) {
return uint(Error.INSUFFICIENT_LIQUIDITY);
}
return uint(Error.NO_ERROR);
}
/**
* @notice Validates redeem and reverts on rejection. May emit logs.
* @param cToken Asset being redeemed
* @param redeemer The address redeeming the tokens
* @param redeemAmount The amount of the underlying asset being redeemed
* @param redeemTokens The number of tokens being redeemed
*/
function redeemVerify(address cToken, address redeemer, uint redeemAmount, uint redeemTokens) external {
// Shh - currently unused
cToken;
redeemer;
// Require tokens is zero or amount is also zero
if (redeemTokens == 0 && redeemAmount > 0) {
revert("redeemTokens zero");
}
}
/**
* @notice Checks if the account should be allowed to borrow the underlying asset of the given market
* @param cToken The market to verify the borrow against
* @param borrower The account which would borrow the asset
* @param borrowAmount The amount of underlying the account would borrow
* @return 0 if the borrow is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
*/
function borrowAllowed(address cToken, address borrower, uint borrowAmount) external returns (uint) {
// Pausing is a very serious situation - we revert to sound the alarms
require(!borrowGuardianPaused[cToken], "borrow is paused");
if (!markets[cToken].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
if (!markets[cToken].accountMembership[borrower]) {
// only cTokens may call borrowAllowed if borrower not in market
require(msg.sender == cToken, "sender must be cToken");
// attempt to add borrower to the market
Error err = addToMarketInternal(CToken(msg.sender), borrower);
if (err != Error.NO_ERROR) {
return uint(err);
}
// it should be impossible to break the important invariant
assert(markets[cToken].accountMembership[borrower]);
}
if (oracle.getUnderlyingPrice(CToken(cToken)) == 0) {
return uint(Error.PRICE_ERROR);
}
(Error err, , uint shortfall) = getHypotheticalAccountLiquidityInternal(borrower, CToken(cToken), 0, borrowAmount);
if (err != Error.NO_ERROR) {
return uint(err);
}
if (shortfall > 0) {
return uint(Error.INSUFFICIENT_LIQUIDITY);
}
// Keep the flywheel moving
Exp memory borrowIndex = Exp({mantissa: CToken(cToken).borrowIndex()});
updateCompBorrowIndex(cToken, borrowIndex);
distributeBorrowerComp(cToken, borrower, borrowIndex, false);
return uint(Error.NO_ERROR);
}
/**
* @notice Validates borrow and reverts on rejection. May emit logs.
* @param cToken Asset whose underlying is being borrowed
* @param borrower The address borrowing the underlying
* @param borrowAmount The amount of the underlying asset requested to borrow
*/
function borrowVerify(address cToken, address borrower, uint borrowAmount) external {
// Shh - currently unused
cToken;
borrower;
borrowAmount;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/**
* @notice Checks if the account should be allowed to repay a borrow in the given market
* @param cToken The market to verify the repay against
* @param payer The account which would repay the asset
* @param borrower The account which would borrowed the asset
* @param repayAmount The amount of the underlying asset the account would repay
* @return 0 if the repay is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
*/
function repayBorrowAllowed(
address cToken,
address payer,
address borrower,
uint repayAmount) external returns (uint) {
// Shh - currently unused
payer;
borrower;
repayAmount;
if (!markets[cToken].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
// Keep the flywheel moving
Exp memory borrowIndex = Exp({mantissa: CToken(cToken).borrowIndex()});
updateCompBorrowIndex(cToken, borrowIndex);
distributeBorrowerComp(cToken, borrower, borrowIndex, false);
return uint(Error.NO_ERROR);
}
/**
* @notice Validates repayBorrow and reverts on rejection. May emit logs.
* @param cToken Asset being repaid
* @param payer The address repaying the borrow
* @param borrower The address of the borrower
* @param actualRepayAmount The amount of underlying being repaid
*/
function repayBorrowVerify(
address cToken,
address payer,
address borrower,
uint actualRepayAmount,
uint borrowerIndex) external {
// Shh - currently unused
cToken;
payer;
borrower;
actualRepayAmount;
borrowerIndex;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/**
* @notice Checks if the liquidation should be allowed to occur
* @param cTokenBorrowed Asset which was borrowed by the borrower
* @param cTokenCollateral Asset which was used as collateral and will be seized
* @param liquidator The address repaying the borrow and seizing the collateral
* @param borrower The address of the borrower
* @param repayAmount The amount of underlying being repaid
*/
function liquidateBorrowAllowed(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint repayAmount) external returns (uint) {
// Shh - currently unused
liquidator;
if (!markets[cTokenBorrowed].isListed || !markets[cTokenCollateral].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
/* The borrower must have shortfall in order to be liquidatable */
(Error err, , uint shortfall) = getAccountLiquidityInternal(borrower);
if (err != Error.NO_ERROR) {
return uint(err);
}
if (shortfall == 0) {
return uint(Error.INSUFFICIENT_SHORTFALL);
}
/* The liquidator may not repay more than what is allowed by the closeFactor */
uint borrowBalance = CToken(cTokenBorrowed).borrowBalanceStored(borrower);
(MathError mathErr, uint maxClose) = mulScalarTruncate(Exp({mantissa: closeFactorMantissa}), borrowBalance);
if (mathErr != MathError.NO_ERROR) {
return uint(Error.MATH_ERROR);
}
if (repayAmount > maxClose) {
return uint(Error.TOO_MUCH_REPAY);
}
return uint(Error.NO_ERROR);
}
/**
* @notice Validates liquidateBorrow and reverts on rejection. May emit logs.
* @param cTokenBorrowed Asset which was borrowed by the borrower
* @param cTokenCollateral Asset which was used as collateral and will be seized
* @param liquidator The address repaying the borrow and seizing the collateral
* @param borrower The address of the borrower
* @param actualRepayAmount The amount of underlying being repaid
*/
function liquidateBorrowVerify(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint actualRepayAmount,
uint seizeTokens) external {
// Shh - currently unused
cTokenBorrowed;
cTokenCollateral;
liquidator;
borrower;
actualRepayAmount;
seizeTokens;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/**
* @notice Checks if the seizing of assets should be allowed to occur
* @param cTokenCollateral Asset which was used as collateral and will be seized
* @param cTokenBorrowed Asset which was borrowed by the borrower
* @param liquidator The address repaying the borrow and seizing the collateral
* @param borrower The address of the borrower
* @param seizeTokens The number of collateral tokens to seize
*/
function seizeAllowed(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external returns (uint) {
// Pausing is a very serious situation - we revert to sound the alarms
require(!seizeGuardianPaused, "seize is paused");
// Shh - currently unused
seizeTokens;
if (!markets[cTokenCollateral].isListed || !markets[cTokenBorrowed].isListed) {
return uint(Error.MARKET_NOT_LISTED);
}
if (CToken(cTokenCollateral).comptroller() != CToken(cTokenBorrowed).comptroller()) {
return uint(Error.COMPTROLLER_MISMATCH);
}
// Keep the flywheel moving
updateCompSupplyIndex(cTokenCollateral);
distributeSupplierComp(cTokenCollateral, borrower, false);
distributeSupplierComp(cTokenCollateral, liquidator, false);
return uint(Error.NO_ERROR);
}
/**
* @notice Validates seize and reverts on rejection. May emit logs.
* @param cTokenCollateral Asset which was used as collateral and will be seized
* @param cTokenBorrowed Asset which was borrowed by the borrower
* @param liquidator The address repaying the borrow and seizing the collateral
* @param borrower The address of the borrower
* @param seizeTokens The number of collateral tokens to seize
*/
function seizeVerify(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external {
// Shh - currently unused
cTokenCollateral;
cTokenBorrowed;
liquidator;
borrower;
seizeTokens;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/**
* @notice Checks if the account should be allowed to transfer tokens in the given market
* @param cToken The market to verify the transfer against
* @param src The account which sources the tokens
* @param dst The account which receives the tokens
* @param transferTokens The number of cTokens to transfer
* @return 0 if the transfer is allowed, otherwise a semi-opaque error code (See ErrorReporter.sol)
*/
function transferAllowed(address cToken, address src, address dst, uint transferTokens) external returns (uint) {
// Pausing is a very serious situation - we revert to sound the alarms
require(!transferGuardianPaused, "transfer is paused");
// Currently the only consideration is whether or not
// the src is allowed to redeem this many tokens
uint allowed = redeemAllowedInternal(cToken, src, transferTokens);
if (allowed != uint(Error.NO_ERROR)) {
return allowed;
}
// Keep the flywheel moving
updateCompSupplyIndex(cToken);
distributeSupplierComp(cToken, src, false);
distributeSupplierComp(cToken, dst, false);
return uint(Error.NO_ERROR);
}
/**
* @notice Validates transfer and reverts on rejection. May emit logs.
* @param cToken Asset being transferred
* @param src The account which sources the tokens
* @param dst The account which receives the tokens
* @param transferTokens The number of cTokens to transfer
*/
function transferVerify(address cToken, address src, address dst, uint transferTokens) external {
// Shh - currently unused
cToken;
src;
dst;
transferTokens;
// Shh - we don't ever want this hook to be marked pure
if (false) {
maxAssets = maxAssets;
}
}
/*** Liquidity/Liquidation Calculations ***/
/**
* @dev Local vars for avoiding stack-depth limits in calculating account liquidity.
* Note that `cTokenBalance` is the number of cTokens the account owns in the market,
* whereas `borrowBalance` is the amount of underlying that the account has borrowed.
*/
struct AccountLiquidityLocalVars {
uint sumCollateral;
uint sumBorrowPlusEffects;
uint cTokenBalance;
uint borrowBalance;
uint exchangeRateMantissa;
uint oraclePriceMantissa;
Exp collateralFactor;
Exp exchangeRate;
Exp oraclePrice;
Exp tokensToDenom;
}
/**
* @notice Determine the current account liquidity wrt collateral requirements
* @return (possible error code (semi-opaque),
account liquidity in excess of collateral requirements,
* account shortfall below collateral requirements)
*/
function getAccountLiquidity(address account) public view returns (uint, uint, uint) {
(Error err, uint liquidity, uint shortfall) = getHypotheticalAccountLiquidityInternal(account, CToken(0), 0, 0);
return (uint(err), liquidity, shortfall);
}
/**
* @notice Determine the current account liquidity wrt collateral requirements
* @return (possible error code,
account liquidity in excess of collateral requirements,
* account shortfall below collateral requirements)
*/
function getAccountLiquidityInternal(address account) internal view returns (Error, uint, uint) {
return getHypotheticalAccountLiquidityInternal(account, CToken(0), 0, 0);
}
/**
* @notice Determine what the account liquidity would be if the given amounts were redeemed/borrowed
* @param cTokenModify The market to hypothetically redeem/borrow in
* @param account The account to determine liquidity for
* @param redeemTokens The number of tokens to hypothetically redeem
* @param borrowAmount The amount of underlying to hypothetically borrow
* @return (possible error code (semi-opaque),
hypothetical account liquidity in excess of collateral requirements,
* hypothetical account shortfall below collateral requirements)
*/
function getHypotheticalAccountLiquidity(
address account,
address cTokenModify,
uint redeemTokens,
uint borrowAmount) public view returns (uint, uint, uint) {
(Error err, uint liquidity, uint shortfall) = getHypotheticalAccountLiquidityInternal(account, CToken(cTokenModify), redeemTokens, borrowAmount);
return (uint(err), liquidity, shortfall);
}
/**
* @notice Determine what the account liquidity would be if the given amounts were redeemed/borrowed
* @param cTokenModify The market to hypothetically redeem/borrow in
* @param account The account to determine liquidity for
* @param redeemTokens The number of tokens to hypothetically redeem
* @param borrowAmount The amount of underlying to hypothetically borrow
* @dev Note that we calculate the exchangeRateStored for each collateral cToken using stored data,
* without calculating accumulated interest.
* @return (possible error code,
hypothetical account liquidity in excess of collateral requirements,
* hypothetical account shortfall below collateral requirements)
*/
function getHypotheticalAccountLiquidityInternal(
address account,
CToken cTokenModify,
uint redeemTokens,
uint borrowAmount) internal view returns (Error, uint, uint) {
AccountLiquidityLocalVars memory vars; // Holds all our calculation results
uint oErr;
MathError mErr;
// For each asset the account is in
CToken[] memory assets = accountAssets[account];
for (uint i = 0; i < assets.length; i++) {
CToken asset = assets[i];
// Read the balances and exchange rate from the cToken
(oErr, vars.cTokenBalance, vars.borrowBalance, vars.exchangeRateMantissa) = asset.getAccountSnapshot(account);
if (oErr != 0) { // semi-opaque error code, we assume NO_ERROR == 0 is invariant between upgrades
return (Error.SNAPSHOT_ERROR, 0, 0);
}
vars.collateralFactor = Exp({mantissa: markets[address(asset)].collateralFactorMantissa});
vars.exchangeRate = Exp({mantissa: vars.exchangeRateMantissa});
// Get the normalized price of the asset
vars.oraclePriceMantissa = oracle.getUnderlyingPrice(asset);
if (vars.oraclePriceMantissa == 0) {
return (Error.PRICE_ERROR, 0, 0);
}
vars.oraclePrice = Exp({mantissa: vars.oraclePriceMantissa});
// Pre-compute a conversion factor from tokens -> ether (normalized price value)
(mErr, vars.tokensToDenom) = mulExp3(vars.collateralFactor, vars.exchangeRate, vars.oraclePrice);
if (mErr != MathError.NO_ERROR) {
return (Error.MATH_ERROR, 0, 0);
}
// sumCollateral += tokensToDenom * cTokenBalance
(mErr, vars.sumCollateral) = mulScalarTruncateAddUInt(vars.tokensToDenom, vars.cTokenBalance, vars.sumCollateral);
if (mErr != MathError.NO_ERROR) {
return (Error.MATH_ERROR, 0, 0);
}
// sumBorrowPlusEffects += oraclePrice * borrowBalance
(mErr, vars.sumBorrowPlusEffects) = mulScalarTruncateAddUInt(vars.oraclePrice, vars.borrowBalance, vars.sumBorrowPlusEffects);
if (mErr != MathError.NO_ERROR) {
return (Error.MATH_ERROR, 0, 0);
}
// Calculate effects of interacting with cTokenModify
if (asset == cTokenModify) {
// redeem effect
// sumBorrowPlusEffects += tokensToDenom * redeemTokens
(mErr, vars.sumBorrowPlusEffects) = mulScalarTruncateAddUInt(vars.tokensToDenom, redeemTokens, vars.sumBorrowPlusEffects);
if (mErr != MathError.NO_ERROR) {
return (Error.MATH_ERROR, 0, 0);
}
// borrow effect
// sumBorrowPlusEffects += oraclePrice * borrowAmount
(mErr, vars.sumBorrowPlusEffects) = mulScalarTruncateAddUInt(vars.oraclePrice, borrowAmount, vars.sumBorrowPlusEffects);
if (mErr != MathError.NO_ERROR) {
return (Error.MATH_ERROR, 0, 0);
}
}
}
// These are safe, as the underflow condition is checked first
if (vars.sumCollateral > vars.sumBorrowPlusEffects) {
return (Error.NO_ERROR, vars.sumCollateral - vars.sumBorrowPlusEffects, 0);
} else {
return (Error.NO_ERROR, 0, vars.sumBorrowPlusEffects - vars.sumCollateral);
}
}
/**
* @notice Calculate number of tokens of collateral asset to seize given an underlying amount
* @dev Used in liquidation (called in cToken.liquidateBorrowFresh)
* @param cTokenBorrowed The address of the borrowed cToken
* @param cTokenCollateral The address of the collateral cToken
* @param actualRepayAmount The amount of cTokenBorrowed underlying to convert into cTokenCollateral tokens
* @return (errorCode, number of cTokenCollateral tokens to be seized in a liquidation)
*/
function liquidateCalculateSeizeTokens(address cTokenBorrowed, address cTokenCollateral, uint actualRepayAmount) external view returns (uint, uint) {
/* Read oracle prices for borrowed and collateral markets */
uint priceBorrowedMantissa = oracle.getUnderlyingPrice(CToken(cTokenBorrowed));
uint priceCollateralMantissa = oracle.getUnderlyingPrice(CToken(cTokenCollateral));
if (priceBorrowedMantissa == 0 || priceCollateralMantissa == 0) {
return (uint(Error.PRICE_ERROR), 0);
}
/*
* Get the exchange rate and calculate the number of collateral tokens to seize:
* seizeAmount = actualRepayAmount * liquidationIncentive * priceBorrowed / priceCollateral
* seizeTokens = seizeAmount / exchangeRate
* = actualRepayAmount * (liquidationIncentive * priceBorrowed) / (priceCollateral * exchangeRate)
*/
uint exchangeRateMantissa = CToken(cTokenCollateral).exchangeRateStored(); // Note: reverts on error
uint seizeTokens;
Exp memory numerator;
Exp memory denominator;
Exp memory ratio;
MathError mathErr;
(mathErr, numerator) = mulExp(liquidationIncentiveMantissa, priceBorrowedMantissa);
if (mathErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0);
}
(mathErr, denominator) = mulExp(priceCollateralMantissa, exchangeRateMantissa);
if (mathErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0);
}
(mathErr, ratio) = divExp(numerator, denominator);
if (mathErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0);
}
(mathErr, seizeTokens) = mulScalarTruncate(ratio, actualRepayAmount);
if (mathErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0);
}
return (uint(Error.NO_ERROR), seizeTokens);
}
/*** Admin Functions ***/
/**
* @notice Sets a new price oracle for the comptroller
* @dev Admin function to set a new price oracle
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _setPriceOracle(PriceOracle newOracle) public returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_PRICE_ORACLE_OWNER_CHECK);
}
// Track the old oracle for the comptroller
PriceOracle oldOracle = oracle;
// Set comptroller's oracle to newOracle
oracle = newOracle;
// Emit NewPriceOracle(oldOracle, newOracle)
emit NewPriceOracle(oldOracle, newOracle);
return uint(Error.NO_ERROR);
}
/**
* @notice Sets the closeFactor used when liquidating borrows
* @dev Admin function to set closeFactor
* @param newCloseFactorMantissa New close factor, scaled by 1e18
* @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
*/
function _setCloseFactor(uint newCloseFactorMantissa) external returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_CLOSE_FACTOR_OWNER_CHECK);
}
Exp memory newCloseFactorExp = Exp({mantissa: newCloseFactorMantissa});
Exp memory lowLimit = Exp({mantissa: closeFactorMinMantissa});
if (lessThanOrEqualExp(newCloseFactorExp, lowLimit)) {
return fail(Error.INVALID_CLOSE_FACTOR, FailureInfo.SET_CLOSE_FACTOR_VALIDATION);
}
Exp memory highLimit = Exp({mantissa: closeFactorMaxMantissa});
if (lessThanExp(highLimit, newCloseFactorExp)) {
return fail(Error.INVALID_CLOSE_FACTOR, FailureInfo.SET_CLOSE_FACTOR_VALIDATION);
}
uint oldCloseFactorMantissa = closeFactorMantissa;
closeFactorMantissa = newCloseFactorMantissa;
emit NewCloseFactor(oldCloseFactorMantissa, closeFactorMantissa);
return uint(Error.NO_ERROR);
}
/**
* @notice Sets the collateralFactor for a market
* @dev Admin function to set per-market collateralFactor
* @param cToken The market to set the factor on
* @param newCollateralFactorMantissa The new collateral factor, scaled by 1e18
* @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
*/
function _setCollateralFactor(CToken cToken, uint newCollateralFactorMantissa) external returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_COLLATERAL_FACTOR_OWNER_CHECK);
}
// Verify market is listed
Market storage market = markets[address(cToken)];
if (!market.isListed) {
return fail(Error.MARKET_NOT_LISTED, FailureInfo.SET_COLLATERAL_FACTOR_NO_EXISTS);
}
Exp memory newCollateralFactorExp = Exp({mantissa: newCollateralFactorMantissa});
// Check collateral factor <= 0.9
Exp memory highLimit = Exp({mantissa: collateralFactorMaxMantissa});
if (lessThanExp(highLimit, newCollateralFactorExp)) {
return fail(Error.INVALID_COLLATERAL_FACTOR, FailureInfo.SET_COLLATERAL_FACTOR_VALIDATION);
}
// If collateral factor != 0, fail if price == 0
if (newCollateralFactorMantissa != 0 && oracle.getUnderlyingPrice(cToken) == 0) {
return fail(Error.PRICE_ERROR, FailureInfo.SET_COLLATERAL_FACTOR_WITHOUT_PRICE);
}
// Set market's collateral factor to new collateral factor, remember old value
uint oldCollateralFactorMantissa = market.collateralFactorMantissa;
market.collateralFactorMantissa = newCollateralFactorMantissa;
// Emit event with asset, old collateral factor, and new collateral factor
emit NewCollateralFactor(cToken, oldCollateralFactorMantissa, newCollateralFactorMantissa);
return uint(Error.NO_ERROR);
}
/**
* @notice Sets maxAssets which controls how many markets can be entered
* @dev Admin function to set maxAssets
* @param newMaxAssets New max assets
* @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
*/
function _setMaxAssets(uint newMaxAssets) external returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_MAX_ASSETS_OWNER_CHECK);
}
uint oldMaxAssets = maxAssets;
maxAssets = newMaxAssets;
emit NewMaxAssets(oldMaxAssets, newMaxAssets);
return uint(Error.NO_ERROR);
}
/**
* @notice Sets liquidationIncentive
* @dev Admin function to set liquidationIncentive
* @param newLiquidationIncentiveMantissa New liquidationIncentive scaled by 1e18
* @return uint 0=success, otherwise a failure. (See ErrorReporter for details)
*/
function _setLiquidationIncentive(uint newLiquidationIncentiveMantissa) external returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_LIQUIDATION_INCENTIVE_OWNER_CHECK);
}
// Check de-scaled min <= newLiquidationIncentive <= max
Exp memory newLiquidationIncentive = Exp({mantissa: newLiquidationIncentiveMantissa});
Exp memory minLiquidationIncentive = Exp({mantissa: liquidationIncentiveMinMantissa});
if (lessThanExp(newLiquidationIncentive, minLiquidationIncentive)) {
return fail(Error.INVALID_LIQUIDATION_INCENTIVE, FailureInfo.SET_LIQUIDATION_INCENTIVE_VALIDATION);
}
Exp memory maxLiquidationIncentive = Exp({mantissa: liquidationIncentiveMaxMantissa});
if (lessThanExp(maxLiquidationIncentive, newLiquidationIncentive)) {
return fail(Error.INVALID_LIQUIDATION_INCENTIVE, FailureInfo.SET_LIQUIDATION_INCENTIVE_VALIDATION);
}
// Save current value for use in log
uint oldLiquidationIncentiveMantissa = liquidationIncentiveMantissa;
// Set liquidation incentive to new incentive
liquidationIncentiveMantissa = newLiquidationIncentiveMantissa;
// Emit event with old incentive, new incentive
emit NewLiquidationIncentive(oldLiquidationIncentiveMantissa, newLiquidationIncentiveMantissa);
return uint(Error.NO_ERROR);
}
/**
* @notice Add the market to the markets mapping and set it as listed
* @dev Admin function to set isListed and add support for the market
* @param cToken The address of the market (token) to list
* @return uint 0=success, otherwise a failure. (See enum Error for details)
*/
function _supportMarket(CToken cToken) external returns (uint) {
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SUPPORT_MARKET_OWNER_CHECK);
}
if (markets[address(cToken)].isListed) {
return fail(Error.MARKET_ALREADY_LISTED, FailureInfo.SUPPORT_MARKET_EXISTS);
}
cToken.isCToken(); // Sanity check to make sure its really a CToken
markets[address(cToken)] = Market({isListed: true, isComped: false, collateralFactorMantissa: 0});
_addMarketInternal(address(cToken));
emit MarketListed(cToken);
return uint(Error.NO_ERROR);
}
function _addMarketInternal(address cToken) internal {
for (uint i = 0; i < allMarkets.length; i ++) {
require(allMarkets[i] != CToken(cToken), "market already added");
}
allMarkets.push(CToken(cToken));
}
/**
* @notice Admin function to change the Pause Guardian
* @param newPauseGuardian The address of the new Pause Guardian
* @return uint 0=success, otherwise a failure. (See enum Error for details)
*/
function _setPauseGuardian(address newPauseGuardian) public returns (uint) {
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_PAUSE_GUARDIAN_OWNER_CHECK);
}
// Save current value for inclusion in log
address oldPauseGuardian = pauseGuardian;
// Store pauseGuardian with value newPauseGuardian
pauseGuardian = newPauseGuardian;
// Emit NewPauseGuardian(OldPauseGuardian, NewPauseGuardian)
emit NewPauseGuardian(oldPauseGuardian, pauseGuardian);
return uint(Error.NO_ERROR);
}
function _setMintPaused(CToken cToken, bool state) public returns (bool) {
require(markets[address(cToken)].isListed, "cannot pause a market that is not listed");
require(msg.sender == pauseGuardian || msg.sender == admin, "only pause guardian and admin can pause");
require(msg.sender == admin || state == true, "only admin can unpause");
mintGuardianPaused[address(cToken)] = state;
emit ActionPaused(cToken, "Mint", state);
return state;
}
function _setBorrowPaused(CToken cToken, bool state) public returns (bool) {
require(markets[address(cToken)].isListed, "cannot pause a market that is not listed");
require(msg.sender == pauseGuardian || msg.sender == admin, "only pause guardian and admin can pause");
require(msg.sender == admin || state == true, "only admin can unpause");
borrowGuardianPaused[address(cToken)] = state;
emit ActionPaused(cToken, "Borrow", state);
return state;
}
function _setTransferPaused(bool state) public returns (bool) {
require(msg.sender == pauseGuardian || msg.sender == admin, "only pause guardian and admin can pause");
require(msg.sender == admin || state == true, "only admin can unpause");
transferGuardianPaused = state;
emit ActionPaused("Transfer", state);
return state;
}
function _setSeizePaused(bool state) public returns (bool) {
require(msg.sender == pauseGuardian || msg.sender == admin, "only pause guardian and admin can pause");
require(msg.sender == admin || state == true, "only admin can unpause");
seizeGuardianPaused = state;
emit ActionPaused("Seize", state);
return state;
}
function _become(Unitroller unitroller) public {
require(msg.sender == unitroller.admin(), "only unitroller admin can change brains");
require(unitroller._acceptImplementation() == 0, "change not authorized");
}
/**
* @notice Checks caller is admin, or this contract is becoming the new implementation
*/
function adminOrInitializing() internal view returns (bool) {
return msg.sender == admin || msg.sender == comptrollerImplementation;
}
/*** Comp Distribution ***/
/**
* @notice Recalculate and update COMP speeds for all COMP markets
*/
function refreshCompSpeeds() public {
require(msg.sender == tx.origin, "only externally owned accounts may refresh speeds");
refreshCompSpeedsInternal();
}
function refreshCompSpeedsInternal() internal {
CToken[] memory allMarkets_ = allMarkets;
for (uint i = 0; i < allMarkets_.length; i++) {
CToken cToken = allMarkets_[i];
Exp memory borrowIndex = Exp({mantissa: cToken.borrowIndex()});
updateCompSupplyIndex(address(cToken));
updateCompBorrowIndex(address(cToken), borrowIndex);
}
Exp memory totalUtility = Exp({mantissa: 0});
Exp[] memory utilities = new Exp[](allMarkets_.length);
for (uint i = 0; i < allMarkets_.length; i++) {
CToken cToken = allMarkets_[i];
if (markets[address(cToken)].isComped) {
Exp memory assetPrice = Exp({mantissa: oracle.getUnderlyingPrice(cToken)});
Exp memory utility = mul_(assetPrice, cToken.totalBorrows());
utilities[i] = utility;
totalUtility = add_(totalUtility, utility);
}
}
for (uint i = 0; i < allMarkets_.length; i++) {
CToken cToken = allMarkets[i];
uint newSpeed = totalUtility.mantissa > 0 ? mul_(compRate, div_(utilities[i], totalUtility)) : 0;
compSpeeds[address(cToken)] = newSpeed;
emit CompSpeedUpdated(cToken, newSpeed);
}
}
/**
* @notice Accrue COMP to the market by updating the supply index
* @param cToken The market whose supply index to update
*/
function updateCompSupplyIndex(address cToken) internal {
CompMarketState storage supplyState = compSupplyState[cToken];
uint supplySpeed = compSpeeds[cToken];
uint blockNumber = getBlockNumber();
uint deltaBlocks = sub_(blockNumber, uint(supplyState.block));
if (deltaBlocks > 0 && supplySpeed > 0) {
uint supplyTokens = CToken(cToken).totalSupply();
uint compAccrued = mul_(deltaBlocks, supplySpeed);
Double memory ratio = supplyTokens > 0 ? fraction(compAccrued, supplyTokens) : Double({mantissa: 0});
Double memory index = add_(Double({mantissa: supplyState.index}), ratio);
compSupplyState[cToken] = CompMarketState({
index: safe224(index.mantissa, "new index exceeds 224 bits"),
block: safe32(blockNumber, "block number exceeds 32 bits")
});
} else if (deltaBlocks > 0) {
supplyState.block = safe32(blockNumber, "block number exceeds 32 bits");
}
}
/**
* @notice Accrue COMP to the market by updating the borrow index
* @param cToken The market whose borrow index to update
*/
function updateCompBorrowIndex(address cToken, Exp memory marketBorrowIndex) internal {
CompMarketState storage borrowState = compBorrowState[cToken];
uint borrowSpeed = compSpeeds[cToken];
uint blockNumber = getBlockNumber();
uint deltaBlocks = sub_(blockNumber, uint(borrowState.block));
if (deltaBlocks > 0 && borrowSpeed > 0) {
uint borrowAmount = div_(CToken(cToken).totalBorrows(), marketBorrowIndex);
uint compAccrued = mul_(deltaBlocks, borrowSpeed);
Double memory ratio = borrowAmount > 0 ? fraction(compAccrued, borrowAmount) : Double({mantissa: 0});
Double memory index = add_(Double({mantissa: borrowState.index}), ratio);
compBorrowState[cToken] = CompMarketState({
index: safe224(index.mantissa, "new index exceeds 224 bits"),
block: safe32(blockNumber, "block number exceeds 32 bits")
});
} else if (deltaBlocks > 0) {
borrowState.block = safe32(blockNumber, "block number exceeds 32 bits");
}
}
/**
* @notice Calculate COMP accrued by a supplier and possibly transfer it to them
* @param cToken The market in which the supplier is interacting
* @param supplier The address of the supplier to distribute COMP to
*/
function distributeSupplierComp(address cToken, address supplier, bool distributeAll) internal {
CompMarketState storage supplyState = compSupplyState[cToken];
Double memory supplyIndex = Double({mantissa: supplyState.index});
Double memory supplierIndex = Double({mantissa: compSupplierIndex[cToken][supplier]});
compSupplierIndex[cToken][supplier] = supplyIndex.mantissa;
if (supplierIndex.mantissa == 0 && supplyIndex.mantissa > 0) {
supplierIndex.mantissa = compInitialIndex;
}
Double memory deltaIndex = sub_(supplyIndex, supplierIndex);
uint supplierTokens = CToken(cToken).balanceOf(supplier);
uint supplierDelta = mul_(supplierTokens, deltaIndex);
uint supplierAccrued = add_(compAccrued[supplier], supplierDelta);
compAccrued[supplier] = transferComp(supplier, supplierAccrued, distributeAll ? 0 : compClaimThreshold);
emit DistributedSupplierComp(CToken(cToken), supplier, supplierDelta, supplyIndex.mantissa);
}
/**
* @notice Calculate COMP accrued by a borrower and possibly transfer it to them
* @dev Borrowers will not begin to accrue until after the first interaction with the protocol.
* @param cToken The market in which the borrower is interacting
* @param borrower The address of the borrower to distribute COMP to
*/
function distributeBorrowerComp(address cToken, address borrower, Exp memory marketBorrowIndex, bool distributeAll) internal {
CompMarketState storage borrowState = compBorrowState[cToken];
Double memory borrowIndex = Double({mantissa: borrowState.index});
Double memory borrowerIndex = Double({mantissa: compBorrowerIndex[cToken][borrower]});
compBorrowerIndex[cToken][borrower] = borrowIndex.mantissa;
if (borrowerIndex.mantissa > 0) {
Double memory deltaIndex = sub_(borrowIndex, borrowerIndex);
uint borrowerAmount = div_(CToken(cToken).borrowBalanceStored(borrower), marketBorrowIndex);
uint borrowerDelta = mul_(borrowerAmount, deltaIndex);
uint borrowerAccrued = add_(compAccrued[borrower], borrowerDelta);
compAccrued[borrower] = transferComp(borrower, borrowerAccrued, distributeAll ? 0 : compClaimThreshold);
emit DistributedBorrowerComp(CToken(cToken), borrower, borrowerDelta, borrowIndex.mantissa);
}
}
/**
* @notice Transfer COMP to the user, if they are above the threshold
* @dev Note: If there is not enough COMP, we do not perform the transfer all.
* @param user The address of the user to transfer COMP to
* @param userAccrued The amount of COMP to (possibly) transfer
* @return The amount of COMP which was NOT transferred to the user
*/
function transferComp(address user, uint userAccrued, uint threshold) internal returns (uint) {
if (userAccrued >= threshold && userAccrued > 0) {
Comp comp = Comp(getCompAddress());
uint compRemaining = comp.balanceOf(address(this));
if (userAccrued <= compRemaining) {
comp.transfer(user, userAccrued);
return 0;
}
}
return userAccrued;
}
/**
* @notice Claim all the comp accrued by holder in all markets
* @param holder The address to claim COMP for
*/
function claimComp(address holder) public {
return claimComp(holder, allMarkets);
}
/**
* @notice Claim all the comp accrued by holder in the specified markets
* @param holder The address to claim COMP for
* @param cTokens The list of markets to claim COMP in
*/
function claimComp(address holder, CToken[] memory cTokens) public {
address[] memory holders = new address[](1);
holders[0] = holder;
claimComp(holders, cTokens, true, true);
}
/**
* @notice Claim all comp accrued by the holders
* @param holders The addresses to claim COMP for
* @param cTokens The list of markets to claim COMP in
* @param borrowers Whether or not to claim COMP earned by borrowing
* @param suppliers Whether or not to claim COMP earned by supplying
*/
function claimComp(address[] memory holders, CToken[] memory cTokens, bool borrowers, bool suppliers) public {
for (uint i = 0; i < cTokens.length; i++) {
CToken cToken = cTokens[i];
require(markets[address(cToken)].isListed, "market must be listed");
if (borrowers == true) {
Exp memory borrowIndex = Exp({mantissa: cToken.borrowIndex()});
updateCompBorrowIndex(address(cToken), borrowIndex);
for (uint j = 0; j < holders.length; j++) {
distributeBorrowerComp(address(cToken), holders[j], borrowIndex, true);
}
}
if (suppliers == true) {
updateCompSupplyIndex(address(cToken));
for (uint j = 0; j < holders.length; j++) {
distributeSupplierComp(address(cToken), holders[j], true);
}
}
}
}
/*** Comp Distribution Admin ***/
/**
* @notice Set the amount of COMP distributed per block
* @param compRate_ The amount of COMP wei per block to distribute
*/
function _setCompRate(uint compRate_) public {
require(adminOrInitializing(), "only admin can change comp rate");
uint oldRate = compRate;
compRate = compRate_;
emit NewCompRate(oldRate, compRate_);
refreshCompSpeedsInternal();
}
/**
* @notice Add markets to compMarkets, allowing them to earn COMP in the flywheel
* @param cTokens The addresses of the markets to add
*/
function _addCompMarkets(address[] memory cTokens) public {
require(adminOrInitializing(), "only admin can add comp market");
for (uint i = 0; i < cTokens.length; i++) {
_addCompMarketInternal(cTokens[i]);
}
refreshCompSpeedsInternal();
}
function _addCompMarketInternal(address cToken) internal {
Market storage market = markets[cToken];
require(market.isListed == true, "comp market is not listed");
require(market.isComped == false, "comp market already added");
market.isComped = true;
emit MarketComped(CToken(cToken), true);
if (compSupplyState[cToken].index == 0 && compSupplyState[cToken].block == 0) {
compSupplyState[cToken] = CompMarketState({
index: compInitialIndex,
block: safe32(getBlockNumber(), "block number exceeds 32 bits")
});
}
if (compBorrowState[cToken].index == 0 && compBorrowState[cToken].block == 0) {
compBorrowState[cToken] = CompMarketState({
index: compInitialIndex,
block: safe32(getBlockNumber(), "block number exceeds 32 bits")
});
}
}
/**
* @notice Remove a market from compMarkets, preventing it from earning COMP in the flywheel
* @param cToken The address of the market to drop
*/
function _dropCompMarket(address cToken) public {
require(msg.sender == admin, "only admin can drop comp market");
Market storage market = markets[cToken];
require(market.isComped == true, "market is not a comp market");
market.isComped = false;
emit MarketComped(CToken(cToken), false);
refreshCompSpeedsInternal();
}
/**
* @notice Return all of the markets
* @dev The automatic getter may be used to access an individual market.
* @return The list of market addresses
*/
function getAllMarkets() public view returns (CToken[] memory) {
return allMarkets;
}
function getBlockNumber() public view returns (uint) {
return block.number;
}
/**
* @notice Return the address of the COMP token
* @return The address of COMP
*/
function getCompAddress() public view returns (address) {
return 0x2ba592F78dB6436527729929AAf6c908497cB200;
}
}
pragma solidity ^0.5.16;
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 returns (uint[] memory);
function exitMarket(address cToken) external returns (uint);
/*** Policy Hooks ***/
function mintAllowed(address cToken, address minter, uint mintAmount) external returns (uint);
function mintVerify(address cToken, address minter, uint mintAmount, uint mintTokens) external;
function redeemAllowed(address cToken, address redeemer, uint redeemTokens) external returns (uint);
function redeemVerify(address cToken, address redeemer, uint redeemAmount, uint redeemTokens) external;
function borrowAllowed(address cToken, address borrower, uint borrowAmount) external returns (uint);
function borrowVerify(address cToken, address borrower, uint borrowAmount) external;
function repayBorrowAllowed(
address cToken,
address payer,
address borrower,
uint repayAmount) external returns (uint);
function repayBorrowVerify(
address cToken,
address payer,
address borrower,
uint repayAmount,
uint borrowerIndex) external;
function liquidateBorrowAllowed(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint repayAmount) external returns (uint);
function liquidateBorrowVerify(
address cTokenBorrowed,
address cTokenCollateral,
address liquidator,
address borrower,
uint repayAmount,
uint seizeTokens) external;
function seizeAllowed(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external returns (uint);
function seizeVerify(
address cTokenCollateral,
address cTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external;
function transferAllowed(address cToken, address src, address dst, uint transferTokens) external returns (uint);
function transferVerify(address cToken, address src, address dst, uint transferTokens) external;
/*** Liquidity/Liquidation Calculations ***/
function liquidateCalculateSeizeTokens(
address cTokenBorrowed,
address cTokenCollateral,
uint repayAmount) external view returns (uint, uint);
}
pragma solidity ^0.5.16;
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 {
/// @notice Whether or not this market is listed
bool isListed;
/**
* @notice 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;
/// @notice Per-market mapping of "accounts in this asset"
mapping(address => bool) accountMembership;
/// @notice 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 {
/// @notice The market's last updated compBorrowIndex or compSupplyIndex
uint224 index;
/// @notice 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;
}
pragma solidity ^0.5.16;
import "./ComptrollerInterface.sol";
import "./CTokenInterfaces.sol";
import "./ErrorReporter.sol";
import "./Exponential.sol";
import "./EIP20Interface.sol";
import "./EIP20NonStandardInterface.sol";
import "./InterestRateModel.sol";
/**
* @title Compound's CToken Contract
* @notice Abstract base for CTokens
* @author Compound
*/
contract CToken is CTokenInterface, Exponential, 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 == uint(Error.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 == uint(Error.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 Whether or not the transfer succeeded
*/
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) {
return failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.TRANSFER_COMPTROLLER_REJECTION, allowed);
}
/* Do not allow self-transfers */
if (src == dst) {
return fail(Error.BAD_INPUT, FailureInfo.TRANSFER_NOT_ALLOWED);
}
/* Get the allowance, infinite for the account owner */
uint startingAllowance = 0;
if (spender == src) {
startingAllowance = uint(-1);
} else {
startingAllowance = transferAllowances[src][spender];
}
/* Do the calculations, checking for {under,over}flow */
MathError mathErr;
uint allowanceNew;
uint srcTokensNew;
uint dstTokensNew;
(mathErr, allowanceNew) = subUInt(startingAllowance, tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ALLOWED);
}
(mathErr, srcTokensNew) = subUInt(accountTokens[src], tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ENOUGH);
}
(mathErr, dstTokensNew) = addUInt(accountTokens[dst], tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_TOO_MUCH);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
accountTokens[src] = srcTokensNew;
accountTokens[dst] = dstTokensNew;
/* Eat some of the allowance (if necessary) */
if (startingAllowance != uint(-1)) {
transferAllowances[src][spender] = allowanceNew;
}
/* We emit a Transfer event */
emit Transfer(src, dst, tokens);
comptroller.transferVerify(address(this), src, dst, tokens);
return uint(Error.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 nonReentrant returns (bool) {
return transferTokens(msg.sender, msg.sender, dst, amount) == uint(Error.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 nonReentrant returns (bool) {
return transferTokens(msg.sender, src, dst, amount) == uint(Error.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 (-1 means infinite)
* @return Whether or not the approval succeeded
*/
function approve(address spender, uint256 amount) 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) 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) 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) external returns (uint) {
Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()});
(MathError mErr, uint balance) = mulScalarTruncate(exchangeRate, accountTokens[owner]);
require(mErr == MathError.NO_ERROR, "balance could not be calculated");
return balance;
}
/**
* @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 returns (uint, uint, uint, uint) {
uint cTokenBalance = accountTokens[account];
uint borrowBalance;
uint exchangeRateMantissa;
MathError mErr;
(mErr, borrowBalance) = borrowBalanceStoredInternal(account);
if (mErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0, 0, 0);
}
(mErr, exchangeRateMantissa) = exchangeRateStoredInternal();
if (mErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0, 0, 0);
}
return (uint(Error.NO_ERROR), cTokenBalance, borrowBalance, exchangeRateMantissa);
}
/**
* @dev Function to simply retrieve block number
* This exists mainly for inheriting test contracts to stub this result.
*/
function getBlockNumber() 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() 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() 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() external nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
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 nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
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 returns (uint) {
(MathError err, uint result) = borrowBalanceStoredInternal(account);
require(err == MathError.NO_ERROR, "borrowBalanceStored: borrowBalanceStoredInternal failed");
return result;
}
/**
* @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 (MathError, uint) {
/* Note: we do not assert that the market is up to date */
MathError mathErr;
uint principalTimesIndex;
uint result;
/* 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 (MathError.NO_ERROR, 0);
}
/* Calculate new borrow balance using the interest index:
* recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex
*/
(mathErr, principalTimesIndex) = mulUInt(borrowSnapshot.principal, borrowIndex);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
(mathErr, result) = divUInt(principalTimesIndex, borrowSnapshot.interestIndex);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
return (MathError.NO_ERROR, result);
}
/**
* @notice Accrue interest then return the up-to-date exchange rate
* @return Calculated exchange rate scaled by 1e18
*/
function exchangeRateCurrent() public nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
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 returns (uint) {
(MathError err, uint result) = exchangeRateStoredInternal();
require(err == MathError.NO_ERROR, "exchangeRateStored: exchangeRateStoredInternal failed");
return result;
}
/**
* @notice Calculates the exchange rate from the underlying to the CToken
* @dev This function does not accrue interest before calculating the exchange rate
* @return (error code, calculated exchange rate scaled by 1e18)
*/
function exchangeRateStoredInternal() internal view returns (MathError, uint) {
uint _totalSupply = totalSupply;
if (_totalSupply == 0) {
/*
* If there are no tokens minted:
* exchangeRate = initialExchangeRate
*/
return (MathError.NO_ERROR, initialExchangeRateMantissa);
} else {
/*
* Otherwise:
* exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply
*/
uint totalCash = getCashPrior();
uint cashPlusBorrowsMinusReserves;
Exp memory exchangeRate;
MathError mathErr;
(mathErr, cashPlusBorrowsMinusReserves) = addThenSubUInt(totalCash, totalBorrows, totalReserves);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
(mathErr, exchangeRate) = getExp(cashPlusBorrowsMinusReserves, _totalSupply);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
return (MathError.NO_ERROR, exchangeRate.mantissa);
}
}
/**
* @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 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() public returns (uint) {
/* Remember the initial block number */
uint currentBlockNumber = getBlockNumber();
uint accrualBlockNumberPrior = accrualBlockNumber;
/* Short-circuit accumulating 0 interest */
if (accrualBlockNumberPrior == currentBlockNumber) {
return uint(Error.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 */
(MathError mathErr, uint blockDelta) = subUInt(currentBlockNumber, accrualBlockNumberPrior);
require(mathErr == MathError.NO_ERROR, "could not calculate block delta");
/*
* 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;
uint interestAccumulated;
uint totalBorrowsNew;
uint totalReservesNew;
uint borrowIndexNew;
(mathErr, simpleInterestFactor) = mulScalar(Exp({mantissa: borrowRateMantissa}), blockDelta);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED, uint(mathErr));
}
(mathErr, interestAccumulated) = mulScalarTruncate(simpleInterestFactor, borrowsPrior);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED, uint(mathErr));
}
(mathErr, totalBorrowsNew) = addUInt(interestAccumulated, borrowsPrior);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED, uint(mathErr));
}
(mathErr, totalReservesNew) = mulScalarTruncateAddUInt(Exp({mantissa: reserveFactorMantissa}), interestAccumulated, reservesPrior);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED, uint(mathErr));
}
(mathErr, borrowIndexNew) = mulScalarTruncateAddUInt(simpleInterestFactor, borrowIndexPrior, borrowIndexPrior);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED, uint(mathErr));
}
/////////////////////////
// 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 uint(Error.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
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual mint amount.
*/
function mintInternal(uint mintAmount) internal nonReentrant returns (uint, uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return (fail(Error(error), FailureInfo.MINT_ACCRUE_INTEREST_FAILED), 0);
}
// mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to
return mintFresh(msg.sender, mintAmount);
}
struct MintLocalVars {
Error err;
MathError mathErr;
uint exchangeRateMantissa;
uint mintTokens;
uint totalSupplyNew;
uint accountTokensNew;
uint actualMintAmount;
}
/**
* @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
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual mint amount.
*/
function mintFresh(address minter, uint mintAmount) internal returns (uint, uint) {
/* Fail if mint not allowed */
uint allowed = comptroller.mintAllowed(address(this), minter, mintAmount);
if (allowed != 0) {
return (failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.MINT_COMPTROLLER_REJECTION, allowed), 0);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return (fail(Error.MARKET_NOT_FRESH, FailureInfo.MINT_FRESHNESS_CHECK), 0);
}
MintLocalVars memory vars;
(vars.mathErr, vars.exchangeRateMantissa) = exchangeRateStoredInternal();
if (vars.mathErr != MathError.NO_ERROR) {
return (failOpaque(Error.MATH_ERROR, FailureInfo.MINT_EXCHANGE_RATE_READ_FAILED, uint(vars.mathErr)), 0);
}
/////////////////////////
// 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.
*/
vars.actualMintAmount = doTransferIn(minter, mintAmount);
/*
* We get the current exchange rate and calculate the number of cTokens to be minted:
* mintTokens = actualMintAmount / exchangeRate
*/
(vars.mathErr, vars.mintTokens) = divScalarByExpTruncate(vars.actualMintAmount, Exp({mantissa: vars.exchangeRateMantissa}));
require(vars.mathErr == MathError.NO_ERROR, "MINT_EXCHANGE_CALCULATION_FAILED");
/*
* We calculate the new total supply of cTokens and minter token balance, checking for overflow:
* totalSupplyNew = totalSupply + mintTokens
* accountTokensNew = accountTokens[minter] + mintTokens
*/
(vars.mathErr, vars.totalSupplyNew) = addUInt(totalSupply, vars.mintTokens);
require(vars.mathErr == MathError.NO_ERROR, "MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED");
(vars.mathErr, vars.accountTokensNew) = addUInt(accountTokens[minter], vars.mintTokens);
require(vars.mathErr == MathError.NO_ERROR, "MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED");
/* We write previously calculated values into storage */
totalSupply = vars.totalSupplyNew;
accountTokens[minter] = vars.accountTokensNew;
/* We emit a Mint event, and a Transfer event */
emit Mint(minter, vars.actualMintAmount, vars.mintTokens);
emit Transfer(address(this), minter, vars.mintTokens);
/* We call the defense hook */
comptroller.mintVerify(address(this), minter, vars.actualMintAmount, vars.mintTokens);
return (uint(Error.NO_ERROR), vars.actualMintAmount);
}
/**
* @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
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeemInternal(uint redeemTokens) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
return fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
}
// redeemFresh emits redeem-specific logs on errors, so we don't need to
return redeemFresh(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
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeemUnderlyingInternal(uint redeemAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
return fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
}
// redeemFresh emits redeem-specific logs on errors, so we don't need to
return redeemFresh(msg.sender, 0, redeemAmount);
}
struct RedeemLocalVars {
Error err;
MathError mathErr;
uint exchangeRateMantissa;
uint redeemTokens;
uint redeemAmount;
uint totalSupplyNew;
uint accountTokensNew;
}
/**
* @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)
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeemFresh(address payable redeemer, uint redeemTokensIn, uint redeemAmountIn) internal returns (uint) {
require(redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero");
RedeemLocalVars memory vars;
/* exchangeRate = invoke Exchange Rate Stored() */
(vars.mathErr, vars.exchangeRateMantissa) = exchangeRateStoredInternal();
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_RATE_READ_FAILED, uint(vars.mathErr));
}
/* 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
*/
vars.redeemTokens = redeemTokensIn;
(vars.mathErr, vars.redeemAmount) = mulScalarTruncate(Exp({mantissa: vars.exchangeRateMantissa}), redeemTokensIn);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED, uint(vars.mathErr));
}
} else {
/*
* We get the current exchange rate and calculate the amount to be redeemed:
* redeemTokens = redeemAmountIn / exchangeRate
* redeemAmount = redeemAmountIn
*/
(vars.mathErr, vars.redeemTokens) = divScalarByExpTruncate(redeemAmountIn, Exp({mantissa: vars.exchangeRateMantissa}));
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED, uint(vars.mathErr));
}
vars.redeemAmount = redeemAmountIn;
}
/* Fail if redeem not allowed */
uint allowed = comptroller.redeemAllowed(address(this), redeemer, vars.redeemTokens);
if (allowed != 0) {
return failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.REDEEM_COMPTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.REDEEM_FRESHNESS_CHECK);
}
/*
* We calculate the new total supply and redeemer balance, checking for underflow:
* totalSupplyNew = totalSupply - redeemTokens
* accountTokensNew = accountTokens[redeemer] - redeemTokens
*/
(vars.mathErr, vars.totalSupplyNew) = subUInt(totalSupply, vars.redeemTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.accountTokensNew) = subUInt(accountTokens[redeemer], vars.redeemTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/* Fail gracefully if protocol has insufficient cash */
if (getCashPrior() < vars.redeemAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.REDEEM_TRANSFER_OUT_NOT_POSSIBLE);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* 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, vars.redeemAmount);
/* We write previously calculated values into storage */
totalSupply = vars.totalSupplyNew;
accountTokens[redeemer] = vars.accountTokensNew;
/* We emit a Transfer event, and a Redeem event */
emit Transfer(redeemer, address(this), vars.redeemTokens);
emit Redeem(redeemer, vars.redeemAmount, vars.redeemTokens);
/* We call the defense hook */
comptroller.redeemVerify(address(this), redeemer, vars.redeemAmount, vars.redeemTokens);
return uint(Error.NO_ERROR);
}
/**
* @notice Sender borrows assets from the protocol to their own address
* @param borrowAmount The amount of the underlying asset to borrow
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function borrowInternal(uint borrowAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return fail(Error(error), FailureInfo.BORROW_ACCRUE_INTEREST_FAILED);
}
// borrowFresh emits borrow-specific logs on errors, so we don't need to
return borrowFresh(msg.sender, borrowAmount);
}
struct BorrowLocalVars {
MathError mathErr;
uint accountBorrows;
uint accountBorrowsNew;
uint totalBorrowsNew;
}
/**
* @notice Users borrow assets from the protocol to their own address
* @param borrowAmount The amount of the underlying asset to borrow
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function borrowFresh(address payable borrower, uint borrowAmount) internal returns (uint) {
/* Fail if borrow not allowed */
uint allowed = comptroller.borrowAllowed(address(this), borrower, borrowAmount);
if (allowed != 0) {
return failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.BORROW_COMPTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.BORROW_FRESHNESS_CHECK);
}
/* Fail gracefully if protocol has insufficient underlying cash */
if (getCashPrior() < borrowAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.BORROW_CASH_NOT_AVAILABLE);
}
BorrowLocalVars memory vars;
/*
* We calculate the new borrower and total borrow balances, failing on overflow:
* accountBorrowsNew = accountBorrows + borrowAmount
* totalBorrowsNew = totalBorrows + borrowAmount
*/
(vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(borrower);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.accountBorrowsNew) = addUInt(vars.accountBorrows, borrowAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.totalBorrowsNew) = addUInt(totalBorrows, borrowAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* 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 write the previously calculated values into storage */
accountBorrows[borrower].principal = vars.accountBorrowsNew;
accountBorrows[borrower].interestIndex = borrowIndex;
totalBorrows = vars.totalBorrowsNew;
/* We emit a Borrow event */
emit Borrow(borrower, borrowAmount, vars.accountBorrowsNew, vars.totalBorrowsNew);
/* We call the defense hook */
comptroller.borrowVerify(address(this), borrower, borrowAmount);
return uint(Error.NO_ERROR);
}
/**
* @notice Sender repays their own borrow
* @param repayAmount The amount to repay
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
*/
function repayBorrowInternal(uint repayAmount) internal nonReentrant returns (uint, uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return (fail(Error(error), FailureInfo.REPAY_BORROW_ACCRUE_INTEREST_FAILED), 0);
}
// repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
return 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
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
*/
function repayBorrowBehalfInternal(address borrower, uint repayAmount) internal nonReentrant returns (uint, uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return (fail(Error(error), FailureInfo.REPAY_BEHALF_ACCRUE_INTEREST_FAILED), 0);
}
// repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
return repayBorrowFresh(msg.sender, borrower, repayAmount);
}
struct RepayBorrowLocalVars {
Error err;
MathError mathErr;
uint repayAmount;
uint borrowerIndex;
uint accountBorrows;
uint accountBorrowsNew;
uint totalBorrowsNew;
uint actualRepayAmount;
}
/**
* @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 undelrying tokens being returned
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
*/
function repayBorrowFresh(address payer, address borrower, uint repayAmount) internal returns (uint, uint) {
/* Fail if repayBorrow not allowed */
uint allowed = comptroller.repayBorrowAllowed(address(this), payer, borrower, repayAmount);
if (allowed != 0) {
return (failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.REPAY_BORROW_COMPTROLLER_REJECTION, allowed), 0);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return (fail(Error.MARKET_NOT_FRESH, FailureInfo.REPAY_BORROW_FRESHNESS_CHECK), 0);
}
RepayBorrowLocalVars memory vars;
/* We remember the original borrowerIndex for verification purposes */
vars.borrowerIndex = accountBorrows[borrower].interestIndex;
/* We fetch the amount the borrower owes, with accumulated interest */
(vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(borrower);
if (vars.mathErr != MathError.NO_ERROR) {
return (failOpaque(Error.MATH_ERROR, FailureInfo.REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED, uint(vars.mathErr)), 0);
}
/* If repayAmount == -1, repayAmount = accountBorrows */
if (repayAmount == uint(-1)) {
vars.repayAmount = vars.accountBorrows;
} else {
vars.repayAmount = 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.
*/
vars.actualRepayAmount = doTransferIn(payer, vars.repayAmount);
/*
* We calculate the new borrower and total borrow balances, failing on underflow:
* accountBorrowsNew = accountBorrows - actualRepayAmount
* totalBorrowsNew = totalBorrows - actualRepayAmount
*/
(vars.mathErr, vars.accountBorrowsNew) = subUInt(vars.accountBorrows, vars.actualRepayAmount);
require(vars.mathErr == MathError.NO_ERROR, "REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED");
(vars.mathErr, vars.totalBorrowsNew) = subUInt(totalBorrows, vars.actualRepayAmount);
require(vars.mathErr == MathError.NO_ERROR, "REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED");
/* We write the previously calculated values into storage */
accountBorrows[borrower].principal = vars.accountBorrowsNew;
accountBorrows[borrower].interestIndex = borrowIndex;
totalBorrows = vars.totalBorrowsNew;
/* We emit a RepayBorrow event */
emit RepayBorrow(payer, borrower, vars.actualRepayAmount, vars.accountBorrowsNew, vars.totalBorrowsNew);
/* We call the defense hook */
comptroller.repayBorrowVerify(address(this), payer, borrower, vars.actualRepayAmount, vars.borrowerIndex);
return (uint(Error.NO_ERROR), vars.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
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
*/
function liquidateBorrowInternal(address borrower, uint repayAmount, CTokenInterface cTokenCollateral) internal nonReentrant returns (uint, uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
return (fail(Error(error), FailureInfo.LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED), 0);
}
error = cTokenCollateral.accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
return (fail(Error(error), FailureInfo.LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED), 0);
}
// liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to
return 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
* @return (uint, uint) An error code (0=success, otherwise a failure, see ErrorReporter.sol), and the actual repayment amount.
*/
function liquidateBorrowFresh(address liquidator, address borrower, uint repayAmount, CTokenInterface cTokenCollateral) internal returns (uint, uint) {
/* Fail if liquidate not allowed */
uint allowed = comptroller.liquidateBorrowAllowed(address(this), address(cTokenCollateral), liquidator, borrower, repayAmount);
if (allowed != 0) {
return (failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.LIQUIDATE_COMPTROLLER_REJECTION, allowed), 0);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return (fail(Error.MARKET_NOT_FRESH, FailureInfo.LIQUIDATE_FRESHNESS_CHECK), 0);
}
/* Verify cTokenCollateral market's block number equals current block number */
if (cTokenCollateral.accrualBlockNumber() != getBlockNumber()) {
return (fail(Error.MARKET_NOT_FRESH, FailureInfo.LIQUIDATE_COLLATERAL_FRESHNESS_CHECK), 0);
}
/* Fail if borrower = liquidator */
if (borrower == liquidator) {
return (fail(Error.INVALID_ACCOUNT_PAIR, FailureInfo.LIQUIDATE_LIQUIDATOR_IS_BORROWER), 0);
}
/* Fail if repayAmount = 0 */
if (repayAmount == 0) {
return (fail(Error.INVALID_CLOSE_AMOUNT_REQUESTED, FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_ZERO), 0);
}
/* Fail if repayAmount = -1 */
if (repayAmount == uint(-1)) {
return (fail(Error.INVALID_CLOSE_AMOUNT_REQUESTED, FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX), 0);
}
/* Fail if repayBorrow fails */
(uint repayBorrowError, uint actualRepayAmount) = repayBorrowFresh(liquidator, borrower, repayAmount);
if (repayBorrowError != uint(Error.NO_ERROR)) {
return (fail(Error(repayBorrowError), FailureInfo.LIQUIDATE_REPAY_BORROW_FRESH_FAILED), 0);
}
/////////////////////////
// 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 == uint(Error.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
uint seizeError;
if (address(cTokenCollateral) == address(this)) {
seizeError = seizeInternal(address(this), liquidator, borrower, seizeTokens);
} else {
seizeError = cTokenCollateral.seize(liquidator, borrower, seizeTokens);
}
/* Revert if seize tokens fails (since we cannot be sure of side effects) */
require(seizeError == uint(Error.NO_ERROR), "token seizure failed");
/* We emit a LiquidateBorrow event */
emit LiquidateBorrow(liquidator, borrower, actualRepayAmount, address(cTokenCollateral), seizeTokens);
/* We call the defense hook */
comptroller.liquidateBorrowVerify(address(this), address(cTokenCollateral), liquidator, borrower, actualRepayAmount, seizeTokens);
return (uint(Error.NO_ERROR), actualRepayAmount);
}
/**
* @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) external nonReentrant returns (uint) {
return seizeInternal(msg.sender, liquidator, borrower, seizeTokens);
}
/**
* @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
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function seizeInternal(address seizerToken, address liquidator, address borrower, uint seizeTokens) internal returns (uint) {
/* Fail if seize not allowed */
uint allowed = comptroller.seizeAllowed(address(this), seizerToken, liquidator, borrower, seizeTokens);
if (allowed != 0) {
return failOpaque(Error.COMPTROLLER_REJECTION, FailureInfo.LIQUIDATE_SEIZE_COMPTROLLER_REJECTION, allowed);
}
/* Fail if borrower = liquidator */
if (borrower == liquidator) {
return fail(Error.INVALID_ACCOUNT_PAIR, FailureInfo.LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER);
}
MathError mathErr;
uint borrowerTokensNew;
uint liquidatorTokensNew;
/*
* We calculate the new borrower and liquidator token balances, failing on underflow/overflow:
* borrowerTokensNew = accountTokens[borrower] - seizeTokens
* liquidatorTokensNew = accountTokens[liquidator] + seizeTokens
*/
(mathErr, borrowerTokensNew) = subUInt(accountTokens[borrower], seizeTokens);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED, uint(mathErr));
}
(mathErr, liquidatorTokensNew) = addUInt(accountTokens[liquidator], seizeTokens);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED, uint(mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/* We write the previously calculated values into storage */
accountTokens[borrower] = borrowerTokensNew;
accountTokens[liquidator] = liquidatorTokensNew;
/* Emit a Transfer event */
emit Transfer(borrower, liquidator, seizeTokens);
/* We call the defense hook */
comptroller.seizeVerify(address(this), seizerToken, liquidator, borrower, seizeTokens);
return uint(Error.NO_ERROR);
}
/*** 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 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() external 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);
}
/**
* @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 returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_COMPTROLLER_OWNER_CHECK);
}
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 uint(Error.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) external nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reserve factor change failed.
return fail(Error(error), FailureInfo.SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED);
}
// _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) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_RESERVE_FACTOR_ADMIN_CHECK);
}
// Verify market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.SET_RESERVE_FACTOR_FRESH_CHECK);
}
// Check newReserveFactor ≤ maxReserveFactor
if (newReserveFactorMantissa > reserveFactorMaxMantissa) {
return fail(Error.BAD_INPUT, FailureInfo.SET_RESERVE_FACTOR_BOUNDS_CHECK);
}
uint oldReserveFactorMantissa = reserveFactorMantissa;
reserveFactorMantissa = newReserveFactorMantissa;
emit NewReserveFactor(oldReserveFactorMantissa, newReserveFactorMantissa);
return uint(Error.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) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reduce reserves failed.
return fail(Error(error), FailureInfo.ADD_RESERVES_ACCRUE_INTEREST_FAILED);
}
// _addReservesFresh emits reserve-addition-specific logs on errors, so we don't need to.
(error, ) = _addReservesFresh(addAmount);
return 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()) {
return (fail(Error.MARKET_NOT_FRESH, FailureInfo.ADD_RESERVES_FRESH_CHECK), 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;
/* Revert on overflow */
require(totalReservesNew >= totalReserves, "add reserves unexpected overflow");
// 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 (uint(Error.NO_ERROR), actualAddAmount);
}
/**
* @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(uint reduceAmount) external nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reduce reserves failed.
return fail(Error(error), FailureInfo.REDUCE_RESERVES_ACCRUE_INTEREST_FAILED);
}
// _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(uint reduceAmount) internal returns (uint) {
// totalReserves - reduceAmount
uint totalReservesNew;
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.REDUCE_RESERVES_ADMIN_CHECK);
}
// We fail gracefully unless market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.REDUCE_RESERVES_FRESH_CHECK);
}
// Fail gracefully if protocol has insufficient underlying cash
if (getCashPrior() < reduceAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.REDUCE_RESERVES_CASH_NOT_AVAILABLE);
}
// Check reduceAmount ≤ reserves[n] (totalReserves)
if (reduceAmount > totalReserves) {
return fail(Error.BAD_INPUT, FailureInfo.REDUCE_RESERVES_VALIDATION);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
totalReservesNew = totalReserves - reduceAmount;
// We checked reduceAmount <= totalReserves above, so this should never revert.
require(totalReservesNew <= totalReserves, "reduce reserves unexpected underflow");
// 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(admin, reduceAmount);
emit ReservesReduced(admin, reduceAmount, totalReservesNew);
return uint(Error.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 returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted change of interest rate model failed
return fail(Error(error), FailureInfo.SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED);
}
// _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) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_INTEREST_RATE_MODEL_OWNER_CHECK);
}
// We fail gracefully unless market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.SET_INTEREST_RATE_MODEL_FRESH_CHECK);
}
// 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 uint(Error.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 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) internal returns (uint);
/**
* @dev Performs a transfer out, ideally returning an explanatory error code upon failure tather 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) 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
}
}
pragma solidity ^0.5.16;
import "./ComptrollerInterface.sol";
import "./InterestRateModel.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;
/**
* @notice Maximum borrow rate that can ever be applied (.0005% / block)
*/
uint internal constant borrowRateMaxMantissa = 0.0005e16;
/**
* @notice 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;
/**
* @notice 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;
/**
* @notice Official record of token balances for each account
*/
mapping (address => uint) internal accountTokens;
/**
* @notice 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;
}
/**
* @notice Mapping of account addresses to outstanding borrow balances
*/
mapping(address => BorrowSnapshot) internal accountBorrows;
}
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);
/**
* @notice Failure event
*/
event Failure(uint error, uint info, uint detail);
/*** User Interface ***/
function transfer(address dst, uint amount) external returns (bool);
function transferFrom(address src, address dst, uint amount) external returns (bool);
function approve(address spender, uint amount) external returns (bool);
function allowance(address owner, address spender) external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function balanceOfUnderlying(address owner) external returns (uint);
function getAccountSnapshot(address account) external view returns (uint, uint, uint, uint);
function borrowRatePerBlock() external view returns (uint);
function supplyRatePerBlock() external view returns (uint);
function totalBorrowsCurrent() external returns (uint);
function borrowBalanceCurrent(address account) external returns (uint);
function borrowBalanceStored(address account) public view returns (uint);
function exchangeRateCurrent() public returns (uint);
function exchangeRateStored() public view returns (uint);
function getCash() external view returns (uint);
function accrueInterest() public returns (uint);
function seize(address liquidator, address borrower, uint seizeTokens) external returns (uint);
/*** Admin Functions ***/
function _setPendingAdmin(address payable newPendingAdmin) external returns (uint);
function _acceptAdmin() external returns (uint);
function _setComptroller(ComptrollerInterface newComptroller) public returns (uint);
function _setReserveFactor(uint newReserveFactorMantissa) external returns (uint);
function _reduceReserves(uint reduceAmount) external returns (uint);
function _setInterestRateModel(InterestRateModel newInterestRateModel) public returns (uint);
}
contract CErc20Storage {
/**
* @notice Underlying asset for this CToken
*/
address public underlying;
}
contract CErc20Interface is CErc20Storage {
/*** User Interface ***/
function mint(uint mintAmount) external returns (uint);
function redeem(uint redeemTokens) external returns (uint);
function redeemUnderlying(uint redeemAmount) external returns (uint);
function borrow(uint borrowAmount) external returns (uint);
function repayBorrow(uint repayAmount) external returns (uint);
function repayBorrowBehalf(address borrower, uint repayAmount) external returns (uint);
function liquidateBorrow(address borrower, uint repayAmount, CTokenInterface cTokenCollateral) external returns (uint);
/*** Admin Functions ***/
function _addReserves(uint addAmount) external returns (uint);
}
contract CDelegationStorage {
/**
* @notice Implementation address for this contract
*/
address public implementation;
}
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) public;
}
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) public;
/**
* @notice Called by the delegator on a delegate to forfeit its responsibility
*/
function _resignImplementation() public;
}
pragma solidity ^0.5.16;
/**
* @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 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 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 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 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 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);
}
pragma solidity ^0.5.16;
/**
* @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 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 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 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);
}
pragma solidity ^0.5.16;
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 {
enum Error {
NO_ERROR,
UNAUTHORIZED,
BAD_INPUT,
COMPTROLLER_REJECTION,
COMPTROLLER_CALCULATION_ERROR,
INTEREST_RATE_MODEL_ERROR,
INVALID_ACCOUNT_PAIR,
INVALID_CLOSE_AMOUNT_REQUESTED,
INVALID_COLLATERAL_FACTOR,
MATH_ERROR,
MARKET_NOT_FRESH,
MARKET_NOT_LISTED,
TOKEN_INSUFFICIENT_ALLOWANCE,
TOKEN_INSUFFICIENT_BALANCE,
TOKEN_INSUFFICIENT_CASH,
TOKEN_TRANSFER_IN_FAILED,
TOKEN_TRANSFER_OUT_FAILED
}
/*
* Note: FailureInfo (but not Error) is kept in alphabetical order
* This is because FailureInfo grows significantly faster, and
* the order of Error has some meaning, while the order of FailureInfo
* is entirely arbitrary.
*/
enum FailureInfo {
ACCEPT_ADMIN_PENDING_ADMIN_CHECK,
ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED,
ACCRUE_INTEREST_BORROW_RATE_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED,
ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED,
BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
BORROW_ACCRUE_INTEREST_FAILED,
BORROW_CASH_NOT_AVAILABLE,
BORROW_FRESHNESS_CHECK,
BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
BORROW_MARKET_NOT_LISTED,
BORROW_COMPTROLLER_REJECTION,
LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED,
LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED,
LIQUIDATE_COLLATERAL_FRESHNESS_CHECK,
LIQUIDATE_COMPTROLLER_REJECTION,
LIQUIDATE_COMPTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED,
LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX,
LIQUIDATE_CLOSE_AMOUNT_IS_ZERO,
LIQUIDATE_FRESHNESS_CHECK,
LIQUIDATE_LIQUIDATOR_IS_BORROWER,
LIQUIDATE_REPAY_BORROW_FRESH_FAILED,
LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED,
LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED,
LIQUIDATE_SEIZE_COMPTROLLER_REJECTION,
LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER,
LIQUIDATE_SEIZE_TOO_MUCH,
MINT_ACCRUE_INTEREST_FAILED,
MINT_COMPTROLLER_REJECTION,
MINT_EXCHANGE_CALCULATION_FAILED,
MINT_EXCHANGE_RATE_READ_FAILED,
MINT_FRESHNESS_CHECK,
MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
MINT_TRANSFER_IN_FAILED,
MINT_TRANSFER_IN_NOT_POSSIBLE,
REDEEM_ACCRUE_INTEREST_FAILED,
REDEEM_COMPTROLLER_REJECTION,
REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED,
REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED,
REDEEM_EXCHANGE_RATE_READ_FAILED,
REDEEM_FRESHNESS_CHECK,
REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
REDEEM_TRANSFER_OUT_NOT_POSSIBLE,
REDUCE_RESERVES_ACCRUE_INTEREST_FAILED,
REDUCE_RESERVES_ADMIN_CHECK,
REDUCE_RESERVES_CASH_NOT_AVAILABLE,
REDUCE_RESERVES_FRESH_CHECK,
REDUCE_RESERVES_VALIDATION,
REPAY_BEHALF_ACCRUE_INTEREST_FAILED,
REPAY_BORROW_ACCRUE_INTEREST_FAILED,
REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_COMPTROLLER_REJECTION,
REPAY_BORROW_FRESHNESS_CHECK,
REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_TRANSFER_IN_NOT_POSSIBLE,
SET_COLLATERAL_FACTOR_OWNER_CHECK,
SET_COLLATERAL_FACTOR_VALIDATION,
SET_COMPTROLLER_OWNER_CHECK,
SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED,
SET_INTEREST_RATE_MODEL_FRESH_CHECK,
SET_INTEREST_RATE_MODEL_OWNER_CHECK,
SET_MAX_ASSETS_OWNER_CHECK,
SET_ORACLE_MARKET_NOT_LISTED,
SET_PENDING_ADMIN_OWNER_CHECK,
SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED,
SET_RESERVE_FACTOR_ADMIN_CHECK,
SET_RESERVE_FACTOR_FRESH_CHECK,
SET_RESERVE_FACTOR_BOUNDS_CHECK,
TRANSFER_COMPTROLLER_REJECTION,
TRANSFER_NOT_ALLOWED,
TRANSFER_NOT_ENOUGH,
TRANSFER_TOO_MUCH,
ADD_RESERVES_ACCRUE_INTEREST_FAILED,
ADD_RESERVES_FRESH_CHECK,
ADD_RESERVES_TRANSFER_IN_NOT_POSSIBLE
}
/**
* @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);
}
}
pragma solidity ^0.5.16;
import "./CarefulMath.sol";
/**
* @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 Exponential is CarefulMath {
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 Creates an exponential from numerator and denominator values.
* Note: Returns an error if (`num` * 10e18) > MAX_INT,
* or if `denom` is zero.
*/
function getExp(uint num, uint denom) pure internal returns (MathError, Exp memory) {
(MathError err0, uint scaledNumerator) = mulUInt(num, expScale);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
(MathError err1, uint rational) = divUInt(scaledNumerator, denom);
if (err1 != MathError.NO_ERROR) {
return (err1, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: rational}));
}
/**
* @dev Adds two exponentials, returning a new exponential.
*/
function addExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError error, uint result) = addUInt(a.mantissa, b.mantissa);
return (error, Exp({mantissa: result}));
}
/**
* @dev Subtracts two exponentials, returning a new exponential.
*/
function subExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError error, uint result) = subUInt(a.mantissa, b.mantissa);
return (error, Exp({mantissa: result}));
}
/**
* @dev Multiply an Exp by a scalar, returning a new Exp.
*/
function mulScalar(Exp memory a, uint scalar) pure internal returns (MathError, Exp memory) {
(MathError err0, uint scaledMantissa) = mulUInt(a.mantissa, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: scaledMantissa}));
}
/**
* @dev Multiply an Exp by a scalar, then truncate to return an unsigned integer.
*/
function mulScalarTruncate(Exp memory a, uint scalar) pure internal returns (MathError, uint) {
(MathError err, Exp memory product) = mulScalar(a, scalar);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return (MathError.NO_ERROR, truncate(product));
}
/**
* @dev Multiply an Exp by a scalar, truncate, then add an to an unsigned integer, returning an unsigned integer.
*/
function mulScalarTruncateAddUInt(Exp memory a, uint scalar, uint addend) pure internal returns (MathError, uint) {
(MathError err, Exp memory product) = mulScalar(a, scalar);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return addUInt(truncate(product), addend);
}
/**
* @dev Divide an Exp by a scalar, returning a new Exp.
*/
function divScalar(Exp memory a, uint scalar) pure internal returns (MathError, Exp memory) {
(MathError err0, uint descaledMantissa) = divUInt(a.mantissa, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: descaledMantissa}));
}
/**
* @dev Divide a scalar by an Exp, returning a new Exp.
*/
function divScalarByExp(uint scalar, Exp memory divisor) pure internal returns (MathError, Exp memory) {
/*
We are doing this as:
getExp(mulUInt(expScale, scalar), divisor.mantissa)
How it works:
Exp = a / b;
Scalar = s;
`s / (a / b)` = `b * s / a` and since for an Exp `a = mantissa, b = expScale`
*/
(MathError err0, uint numerator) = mulUInt(expScale, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return getExp(numerator, divisor.mantissa);
}
/**
* @dev Divide a scalar by an Exp, then truncate to return an unsigned integer.
*/
function divScalarByExpTruncate(uint scalar, Exp memory divisor) pure internal returns (MathError, uint) {
(MathError err, Exp memory fraction) = divScalarByExp(scalar, divisor);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return (MathError.NO_ERROR, truncate(fraction));
}
/**
* @dev Multiplies two exponentials, returning a new exponential.
*/
function mulExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError err0, uint doubleScaledProduct) = mulUInt(a.mantissa, b.mantissa);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
// We add half the scale before dividing so that we get rounding instead of truncation.
// See "Listing 6" and text above it at https://accu.org/index.php/journals/1717
// Without this change, a result like 6.6...e-19 will be truncated to 0 instead of being rounded to 1e-18.
(MathError err1, uint doubleScaledProductWithHalfScale) = addUInt(halfExpScale, doubleScaledProduct);
if (err1 != MathError.NO_ERROR) {
return (err1, Exp({mantissa: 0}));
}
(MathError err2, uint product) = divUInt(doubleScaledProductWithHalfScale, expScale);
// The only error `div` can return is MathError.DIVISION_BY_ZERO but we control `expScale` and it is not zero.
assert(err2 == MathError.NO_ERROR);
return (MathError.NO_ERROR, Exp({mantissa: product}));
}
/**
* @dev Multiplies two exponentials given their mantissas, returning a new exponential.
*/
function mulExp(uint a, uint b) pure internal returns (MathError, Exp memory) {
return mulExp(Exp({mantissa: a}), Exp({mantissa: b}));
}
/**
* @dev Multiplies three exponentials, returning a new exponential.
*/
function mulExp3(Exp memory a, Exp memory b, Exp memory c) pure internal returns (MathError, Exp memory) {
(MathError err, Exp memory ab) = mulExp(a, b);
if (err != MathError.NO_ERROR) {
return (err, ab);
}
return mulExp(ab, c);
}
/**
* @dev Divides two exponentials, returning a new exponential.
* (a/scale) / (b/scale) = (a/scale) * (scale/b) = a/b,
* which we can scale as an Exp by calling getExp(a.mantissa, b.mantissa)
*/
function divExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
return getExp(a.mantissa, b.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 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 add_(a, b, "addition overflow");
}
function add_(uint a, uint b, string memory errorMessage) pure internal returns (uint) {
uint c = a + b;
require(c >= a, errorMessage);
return c;
}
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 sub_(a, b, "subtraction underflow");
}
function sub_(uint a, uint b, string memory errorMessage) pure internal returns (uint) {
require(b <= a, errorMessage);
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 mul_(a, b, "multiplication overflow");
}
function mul_(uint a, uint b, string memory errorMessage) pure internal returns (uint) {
if (a == 0 || b == 0) {
return 0;
}
uint c = a * b;
require(c / a == b, errorMessage);
return c;
}
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 div_(a, b, "divide by zero");
}
function div_(uint a, uint b, string memory errorMessage) pure internal returns (uint) {
require(b > 0, errorMessage);
return a / b;
}
function fraction(uint a, uint b) pure internal returns (Double memory) {
return Double({mantissa: div_(mul_(a, doubleScale), b)});
}
}
pragma solidity ^0.5.16;
/**
* @title Compound's InterestRateModel Interface
* @author Compound
*/
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 amnount 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 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 amnount 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 returns (uint);
}
pragma solidity ^0.5.16;
import "./CToken.sol";
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 returns (uint);
}
pragma solidity ^0.5.16;
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.
*/
function () 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) }
}
}
}