Instadapp/aave-protocol-v2
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initial implementation

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This commit is contained in:
The3D 2020-10-22 18:15:56 +02:00
parent cdcb5c7d31
commit 8873b9cdac
3 changed files with 63 additions and 44 deletions
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8
contracts/interfaces/ILendingPool.sol
View File

@ -270,10 +270,10 @@ interface ILendingPool {
* @param referralCode the referral code of the caller
**/
function flashLoan(
address receiver,
address reserve,
uint256 amount,
uint256 debtType,
address receiverAddress,
address[] calldata assets,
uint256[] calldata amounts,
uint256 mode,
bytes calldata params,
uint16 referralCode
) external;

91
contracts/lendingpool/LendingPool.sol
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@ -483,11 +483,9 @@ contract LendingPool is VersionedInitializable, ILendingPool, LendingPoolStorage
}
struct FlashLoanLocalVars {
uint256 premium;
uint256 amountPlusPremium;
IFlashLoanReceiver receiver;
address aTokenAddress;
address oracle;
ReserveLogic.InterestRateMode debtMode;
}
/**
@ -495,68 +493,83 @@ contract LendingPool is VersionedInitializable, ILendingPool, LendingPoolStorage
* as long as the amount taken plus a fee is returned. NOTE There are security concerns for developers of flashloan receiver contracts
* that must be kept into consideration. For further details please visit https://developers.aave.com
* @param receiverAddress The address of the contract receiving the funds. The receiver should implement the IFlashLoanReceiver interface.
* @param asset The address of the principal reserve
* @param amount The amount requested for this flashloan
* @param assets The address of the principal reserve
* @param amounts The amount requested for this flashloan
* @param mode Type of the debt to open if the flash loan is not returned. 0 -> Don't open any debt, just revert, 1 -> stable, 2 -> variable
* @param params Variadic packed params to pass to the receiver as extra information
* @param referralCode Referral code of the flash loan
**/
function flashLoan(
address receiverAddress,
address asset,
uint256 amount,
address[] calldata assets,
uint256[] calldata amounts,
uint256 mode,
bytes calldata params,
uint16 referralCode
) external override {
_whenNotPaused();
ReserveLogic.ReserveData storage reserve = _reserves[asset];
FlashLoanLocalVars memory vars;
vars.aTokenAddress = reserve.aTokenAddress;
ValidationLogic.validateFlashloan(assets, amounts, mode, vars.premium);
vars.premium = amount.mul(FLASHLOAN_PREMIUM_TOTAL).div(10000);
ValidationLogic.validateFlashloan(mode, vars.premium);
ReserveLogic.InterestRateMode debtMode = ReserveLogic.InterestRateMode(mode);
address[] memory aTokenAddresses = new address[](assets.length);
uint256[] memory premiums = new uint256[](assets.length);
vars.receiver = IFlashLoanReceiver(receiverAddress);
vars.debtMode = ReserveLogic.InterestRateMode(mode);
//transfer funds to the receiver
IAToken(vars.aTokenAddress).transferUnderlyingTo(receiverAddress, amount);
for (uint256 i = 0; i < assets.length; i++) {
ReserveLogic.ReserveData storage reserve = _reserves[assets[i]];
aTokenAddresses[i] = reserve.aTokenAddress;
premiums[i] = amounts[i].mul(FLASHLOAN_PREMIUM_TOTAL).div(10000);
//transfer funds to the receiver
IAToken(vars.aTokenAddress).transferUnderlyingTo(receiverAddress, amounts[i]);
}
//execute action of the receiver
require(
vars.receiver.executeOperation(asset, amount, vars.premium, params),
vars.receiver.executeOperation(assets, amounts, premiums, params),
Errors.INVALID_FLASH_LOAN_EXECUTOR_RETURN
);
vars.amountPlusPremium = amount.add(vars.premium);
for (uint256 i = 0; i < assets.length; i++) {
uint256 amountPlusPremium = amounts[i].add(premiums[i]);
if (debtMode == ReserveLogic.InterestRateMode.NONE) {
IERC20(asset).safeTransferFrom(receiverAddress, vars.aTokenAddress, vars.amountPlusPremium);
if (vars.debtMode == ReserveLogic.InterestRateMode.NONE) {
_reserves[assets[i]].updateState();
_reserves[assets[i]].cumulateToLiquidityIndex(
IERC20(aTokenAddresses[i]).totalSupply(),
vars.premium
);
_reserves[assets[i]].updateInterestRates(assets[i], aTokenAddresses[i], vars.premium, 0);
reserve.updateState();
reserve.cumulateToLiquidityIndex(IERC20(vars.aTokenAddress).totalSupply(), vars.premium);
reserve.updateInterestRates(asset, vars.aTokenAddress, vars.premium, 0);
IERC20(assets[i]).safeTransferFrom(
receiverAddress,
vars.aTokenAddresses[i],
vars.amountPlusPremium
);
emit FlashLoan(receiverAddress, asset, amount, vars.premium, referralCode);
} else {
//if the user didn't choose to return the funds, the system checks if there
//is enough collateral and eventually open a position
_executeBorrow(
ExecuteBorrowParams(
asset,
msg.sender,
msg.sender,
vars.amountPlusPremium,
mode,
vars.aTokenAddress,
referralCode,
false
)
);
emit FlashLoan(receiverAddress, assets[i], amounts[i], vars.premium, referralCode);
} else {
//if the user didn't choose to return the funds, the system checks if there
//is enough collateral and eventually open a position
_executeBorrow(
ExecuteBorrowParams(
assets[i],
msg.sender,
msg.sender,
amountPlusPremium,
vars.mode,
aTokenAddresses[i],
referralCode,
false
)
);
}
}
}

8
contracts/libraries/logic/ValidationLogic.sol
View File

@ -329,9 +329,15 @@ library ValidationLogic {
* @param mode the flashloan mode (0 = classic flashloan, 1 = open a stable rate loan, 2 = open a variable rate loan)
* @param premium the premium paid on the flashloan
**/
function validateFlashloan(uint256 mode, uint256 premium) internal pure {
function validateFlashloan(
address[] memory assets,
address[] memory amounts,
uint256 mode,
uint256 premium
) internal pure {
require(premium > 0, Errors.REQUESTED_AMOUNT_TOO_SMALL);
require(mode <= uint256(ReserveLogic.InterestRateMode.VARIABLE), Errors.INVALID_FLASHLOAN_MODE);
require(assets.length == amounts.length, Errors.INCONSISTENT_FLASHLOAN_PARAMS);
}
/**