mirror of
https://github.com/Instadapp/aave-protocol-v2.git
synced 2024-07-29 21:47:30 +00:00
Use diff balances instead of liquidation logic for flash liquidations
This commit is contained in:
root
parent
f05550fc04
commit
55f14c1af9
|
|
@ -30,20 +30,11 @@ contract FlashLiquidationAdapter is BaseUniswapAdapter {
|
|||
}
|
||||
|
||||
struct LiquidationCallLocalVars {
|
||||
uint256 userCollateralBalance;
|
||||
uint256 userStableDebt;
|
||||
uint256 userVariableDebt;
|
||||
uint256 maxLiquidatableDebt;
|
||||
uint256 actualDebtToLiquidate;
|
||||
uint256 maxAmountCollateralToLiquidate;
|
||||
uint256 maxCollateralToLiquidate;
|
||||
uint256 debtAmountNeeded;
|
||||
uint256 collateralPrice;
|
||||
uint256 debtAssetPrice;
|
||||
uint256 liquidationBonus;
|
||||
uint256 collateralDecimals;
|
||||
uint256 debtAssetDecimals;
|
||||
IAToken collateralAtoken;
|
||||
uint256 initCollateralBalance;
|
||||
uint256 diffCollateralBalance;
|
||||
uint256 flashLoanDebt;
|
||||
uint256 soldAmount;
|
||||
uint256 remainingTokens;
|
||||
}
|
||||
|
||||
constructor(
|
||||
|
|
@ -115,63 +106,38 @@ contract FlashLiquidationAdapter is BaseUniswapAdapter {
|
|||
uint256 premium,
|
||||
address initiator
|
||||
) internal {
|
||||
DataTypes.ReserveData memory collateralReserve = LENDING_POOL.getReserveData(collateralAsset);
|
||||
DataTypes.ReserveData memory debtReserve = LENDING_POOL.getReserveData(debtAsset);
|
||||
LiquidationCallLocalVars memory vars;
|
||||
vars.initCollateralBalance = IERC20(collateralAsset).balanceOf(address(this));
|
||||
vars.flashLoanDebt = coverAmount.add(premium);
|
||||
|
||||
(vars.userStableDebt, vars.userVariableDebt) = Helpers.getUserCurrentDebtMemory(
|
||||
user,
|
||||
debtReserve
|
||||
);
|
||||
vars.collateralAtoken = IAToken(collateralReserve.aTokenAddress);
|
||||
vars.maxLiquidatableDebt = vars.userStableDebt.add(vars.userVariableDebt).percentMul(
|
||||
LIQUIDATION_CLOSE_FACTOR_PERCENT
|
||||
);
|
||||
|
||||
vars.userCollateralBalance = vars.collateralAtoken.balanceOf(user);
|
||||
vars.actualDebtToLiquidate = debtToCover > vars.maxLiquidatableDebt
|
||||
? vars.maxLiquidatableDebt
|
||||
: debtToCover;
|
||||
|
||||
(
|
||||
vars.maxCollateralToLiquidate,
|
||||
vars.debtAmountNeeded
|
||||
) = _calculateAvailableCollateralToLiquidate(
|
||||
collateralReserve,
|
||||
debtReserve,
|
||||
collateralAsset,
|
||||
debtAsset,
|
||||
vars.actualDebtToLiquidate,
|
||||
vars.userCollateralBalance
|
||||
);
|
||||
|
||||
require(coverAmount >= vars.debtAmountNeeded, 'FLASH_COVER_NOT_ENOUGH');
|
||||
|
||||
uint256 flashLoanDebt = coverAmount.add(premium);
|
||||
|
||||
// Approve LendingPool to use debt token for liquidation
|
||||
IERC20(debtAsset).approve(address(LENDING_POOL), debtToCover);
|
||||
|
||||
// Liquidate the user position and release the underlying collateral
|
||||
LENDING_POOL.liquidationCall(collateralAsset, debtAsset, user, debtToCover, false);
|
||||
|
||||
// Discover the liquidated tokens
|
||||
vars.diffCollateralBalance = IERC20(collateralAsset).balanceOf(address(this)).sub(
|
||||
vars.initCollateralBalance
|
||||
);
|
||||
|
||||
// Swap released collateral into the debt asset, to repay the flash loan
|
||||
uint256 soldAmount =
|
||||
_swapTokensForExactTokens(
|
||||
collateralAsset,
|
||||
debtAsset,
|
||||
vars.maxCollateralToLiquidate,
|
||||
flashLoanDebt,
|
||||
useEthPath
|
||||
);
|
||||
vars.soldAmount = _swapTokensForExactTokens(
|
||||
collateralAsset,
|
||||
debtAsset,
|
||||
vars.diffCollateralBalance,
|
||||
vars.flashLoanDebt,
|
||||
useEthPath
|
||||
);
|
||||
|
||||
// Repay flash loan
|
||||
IERC20(debtAsset).approve(address(LENDING_POOL), flashLoanDebt);
|
||||
// Allow repay of flash loan
|
||||
IERC20(debtAsset).approve(address(LENDING_POOL), vars.flashLoanDebt);
|
||||
|
||||
uint256 remainingTokens = vars.maxCollateralToLiquidate.sub(soldAmount);
|
||||
vars.remainingTokens = vars.diffCollateralBalance.sub(vars.soldAmount);
|
||||
|
||||
// Transfer remaining tokens to initiator
|
||||
if (remainingTokens > 0) {
|
||||
IERC20(collateralAsset).transfer(initiator, remainingTokens);
|
||||
if (vars.remainingTokens > 0) {
|
||||
IERC20(collateralAsset).transfer(initiator, vars.remainingTokens);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -196,64 +162,4 @@ contract FlashLiquidationAdapter is BaseUniswapAdapter {
|
|||
|
||||
return LiquidationParams(collateralAsset, debtAsset, user, debtToCover, useEthPath);
|
||||
}
|
||||
|
||||
/**
|
||||
* @dev Calculates how much of a specific collateral can be liquidated, given
|
||||
* a certain amount of debt asset.
|
||||
* - This function needs to be called after all the checks to validate the liquidation have been performed,
|
||||
* otherwise it might fail.
|
||||
* @param collateralReserve The data of the collateral reserve
|
||||
* @param debtReserve The data of the debt reserve
|
||||
* @param collateralAsset The address of the underlying asset used as collateral, to receive as result of the liquidation
|
||||
* @param debtAsset The address of the underlying borrowed asset to be repaid with the liquidation
|
||||
* @param debtToCover The debt amount of borrowed `asset` the liquidator wants to cover
|
||||
* @param userCollateralBalance The collateral balance for the specific `collateralAsset` of the user being liquidated
|
||||
* @return collateralAmount: The maximum amount that is possible to liquidate given all the liquidation constraints
|
||||
* (user balance, close factor)
|
||||
* debtAmountNeeded: The amount to repay with the liquidation
|
||||
**/
|
||||
function _calculateAvailableCollateralToLiquidate(
|
||||
DataTypes.ReserveData memory collateralReserve,
|
||||
DataTypes.ReserveData memory debtReserve,
|
||||
address collateralAsset,
|
||||
address debtAsset,
|
||||
uint256 debtToCover,
|
||||
uint256 userCollateralBalance
|
||||
) internal view returns (uint256, uint256) {
|
||||
uint256 collateralAmount = 0;
|
||||
uint256 debtAmountNeeded = 0;
|
||||
|
||||
LiquidationCallLocalVars memory vars;
|
||||
|
||||
vars.collateralPrice = ORACLE.getAssetPrice(collateralAsset);
|
||||
vars.debtAssetPrice = ORACLE.getAssetPrice(debtAsset);
|
||||
|
||||
(, , vars.liquidationBonus, vars.collateralDecimals, ) = collateralReserve
|
||||
.configuration
|
||||
.getParamsMemory();
|
||||
(, , , vars.debtAssetDecimals, ) = debtReserve.configuration.getParamsMemory();
|
||||
|
||||
// This is the maximum possible amount of the selected collateral that can be liquidated, given the
|
||||
// max amount of liquidatable debt
|
||||
vars.maxAmountCollateralToLiquidate = vars
|
||||
.debtAssetPrice
|
||||
.mul(debtToCover)
|
||||
.mul(10**vars.collateralDecimals)
|
||||
.percentMul(vars.liquidationBonus)
|
||||
.div(vars.collateralPrice.mul(10**vars.debtAssetDecimals));
|
||||
|
||||
if (vars.maxAmountCollateralToLiquidate > userCollateralBalance) {
|
||||
collateralAmount = userCollateralBalance;
|
||||
debtAmountNeeded = vars
|
||||
.collateralPrice
|
||||
.mul(collateralAmount)
|
||||
.mul(10**vars.debtAssetDecimals)
|
||||
.div(vars.debtAssetPrice.mul(10**vars.collateralDecimals))
|
||||
.percentDiv(vars.liquidationBonus);
|
||||
} else {
|
||||
collateralAmount = vars.maxAmountCollateralToLiquidate;
|
||||
debtAmountNeeded = debtToCover;
|
||||
}
|
||||
return (collateralAmount, debtAmountNeeded);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -18,13 +18,13 @@ const { expect } = require('chai');
|
|||
makeSuite('Uniswap adapters', (testEnv: TestEnv) => {
|
||||
let mockUniswapRouter: MockUniswapV2Router02;
|
||||
let evmSnapshotId: string;
|
||||
const { INVALID_HF, LP_LIQUIDATION_CALL_FAILED } = ProtocolErrors;
|
||||
|
||||
before(async () => {
|
||||
mockUniswapRouter = await getMockUniswapRouter();
|
||||
});
|
||||
|
||||
const depositAndHFBelowOne = async () => {
|
||||
const { INVALID_HF } = ProtocolErrors;
|
||||
const { dai, weth, users, pool, oracle } = testEnv;
|
||||
const depositor = users[0];
|
||||
const borrower = users[1];
|
||||
|
|
@ -643,7 +643,7 @@ makeSuite('Uniswap adapters', (testEnv: TestEnv) => {
|
|||
params,
|
||||
0
|
||||
)
|
||||
).to.be.revertedWith('FLASH_COVER_NOT_ENOUGH');
|
||||
).to.be.revertedWith(LP_LIQUIDATION_CALL_FAILED);
|
||||
});
|
||||
|
||||
it('Revert if requested multiple assets', async () => {
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user