From 773bdd252b311a1929c26b9339ace1b78c41e533 Mon Sep 17 00:00:00 2001
From: The3D <frangellaemilio@gmail.com>
Date: Thu, 14 Jan 2021 15:21:42 +0100
Subject: [PATCH] Added latest fixes
---
contracts/adapters/BaseUniswapAdapter.sol | 28 ++++++++---
.../adapters/UniswapLiquiditySwapAdapter.sol | 46 +++++++++++++------
contracts/adapters/UniswapRepayAdapter.sol | 21 +++++----
3 files changed, 64 insertions(+), 31 deletions(-)
diff --git a/contracts/adapters/BaseUniswapAdapter.sol b/contracts/adapters/BaseUniswapAdapter.sol
index 8cd80faf..b04bc8a1 100644
--- a/contracts/adapters/BaseUniswapAdapter.sol
+++ b/contracts/adapters/BaseUniswapAdapter.sol
@@ -150,7 +150,9 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
require(expectedMinAmountOut < minAmountOut, 'minAmountOut exceed max slippage');
- IERC20(assetToSwapFrom).approve(address(UNISWAP_ROUTER), amountToSwap);
+ // Approves the transfer for the swap. Approves for 0 first to comply with tokens that implement the anti frontrunning approval fix.
+ IERC20(assetToSwapFrom).safeApprove(address(UNISWAP_ROUTER), 0);
+ IERC20(assetToSwapFrom).safeApprove(address(UNISWAP_ROUTER), amountToSwap);
address[] memory path;
if (useEthPath) {
@@ -190,7 +192,8 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
address assetToSwapFrom,
address assetToSwapTo,
uint256 maxAmountToSwap,
- uint256 amountToReceive
+ uint256 amountToReceive,
+ bool useEthPath
) internal returns (uint256) {
uint256 fromAssetDecimals = _getDecimals(assetToSwapFrom);
uint256 toAssetDecimals = _getDecimals(assetToSwapTo);
@@ -206,11 +209,22 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
require(maxAmountToSwap < expectedMaxAmountToSwap, 'maxAmountToSwap exceed max slippage');
- IERC20(assetToSwapFrom).approve(address(UNISWAP_ROUTER), maxAmountToSwap);
+ // Approves the transfer for the swap. Approves for 0 first to comply with tokens that implement the anti frontrunning approval fix.
+ IERC20(assetToSwapFrom).safeApprove(address(UNISWAP_ROUTER), 0);
+ IERC20(assetToSwapFrom).safeApprove(address(UNISWAP_ROUTER), maxAmountToSwap);
+
+ address[] memory path;
+ if (useEthPath) {
+ path = new address[](3);
+ path[0] = assetToSwapFrom;
+ path[1] = WETH_ADDRESS;
+ path[2] = assetToSwapTo;
+ } else {
+ path = new address[](2);
+ path[0] = assetToSwapFrom;
+ path[1] = assetToSwapTo;
+ }
- address[] memory path = new address[](2);
- path[0] = assetToSwapFrom;
- path[1] = assetToSwapTo;
uint256[] memory amounts =
UNISWAP_ROUTER.swapTokensForExactTokens(
amountToReceive,
@@ -472,7 +486,7 @@ abstract contract BaseUniswapAdapter is FlashLoanReceiverBase, IBaseUniswapAdapt
amountsWithoutWeth = resultAmounts;
return
- (amountsWithWeth[2] > amountsWithoutWeth[1])
+ (amountsWithWeth[0] < amountsWithoutWeth[0] && amountsWithWeth[0] != 0)
? (amountsWithWeth, pathWithWeth)
: (amountsWithoutWeth, simplePath);
} catch {
diff --git a/contracts/adapters/UniswapLiquiditySwapAdapter.sol b/contracts/adapters/UniswapLiquiditySwapAdapter.sol
index aaf13406..44745ad5 100644
--- a/contracts/adapters/UniswapLiquiditySwapAdapter.sol
+++ b/contracts/adapters/UniswapLiquiditySwapAdapter.sol
@@ -170,7 +170,8 @@ contract UniswapLiquiditySwapAdapter is BaseUniswapAdapter {
);
// Deposit new reserve
- IERC20(assetToSwapToList[vars.i]).approve(address(LENDING_POOL), vars.receivedAmount);
+ IERC20(assetToSwapToList[vars.i]).safeApprove(address(LENDING_POOL), 0);
+ IERC20(assetToSwapToList[vars.i]).safeApprove(address(LENDING_POOL), vars.receivedAmount);
LENDING_POOL.deposit(assetToSwapToList[vars.i], vars.receivedAmount, msg.sender, 0);
}
}
@@ -186,6 +187,16 @@ contract UniswapLiquiditySwapAdapter is BaseUniswapAdapter {
* @param permitSignature List of struct containing the permit signature
* @param useEthPath true if the swap needs to occur using ETH in the routing, false otherwise
*/
+
+ struct SwapLiquidityLocalVars {
+ address aToken;
+ uint256 aTokenInitiatorBalance;
+ uint256 amountToSwap;
+ uint256 receivedAmount;
+ uint256 flashLoanDebt;
+ uint256 amountToPull;
+ }
+
function _swapLiquidity(
address assetFrom,
address assetTo,
@@ -197,28 +208,33 @@ contract UniswapLiquiditySwapAdapter is BaseUniswapAdapter {
PermitSignature memory permitSignature,
bool useEthPath
) internal {
- address aToken = _getReserveData(assetFrom).aTokenAddress;
+
+ SwapLiquidityLocalVars memory vars;
+
+ vars.aToken = _getReserveData(assetFrom).aTokenAddress;
- uint256 aTokenInitiatorBalance = IERC20(aToken).balanceOf(initiator);
- uint256 amountToSwap =
- swapAllBalance && aTokenInitiatorBalance.sub(premium) <= amount
- ? aTokenInitiatorBalance.sub(premium)
+ vars.aTokenInitiatorBalance = IERC20(vars.aToken).balanceOf(initiator);
+ vars.amountToSwap =
+ swapAllBalance && vars.aTokenInitiatorBalance.sub(premium) <= amount
+ ? vars.aTokenInitiatorBalance.sub(premium)
: amount;
- uint256 receivedAmount =
- _swapExactTokensForTokens(assetFrom, assetTo, amountToSwap, minAmountToReceive, useEthPath);
+ vars.receivedAmount =
+ _swapExactTokensForTokens(assetFrom, assetTo, vars.amountToSwap, minAmountToReceive, useEthPath);
// Deposit new reserve
- IERC20(assetTo).approve(address(LENDING_POOL), receivedAmount);
- LENDING_POOL.deposit(assetTo, receivedAmount, initiator, 0);
+ IERC20(assetTo).safeApprove(address(LENDING_POOL), 0);
+ IERC20(assetTo).safeApprove(address(LENDING_POOL), vars.receivedAmount);
+ LENDING_POOL.deposit(assetTo, vars.receivedAmount, initiator, 0);
- uint256 flashLoanDebt = amount.add(premium);
- uint256 amountToPull = amountToSwap.add(premium);
+ vars.flashLoanDebt = amount.add(premium);
+ vars.amountToPull = vars.amountToSwap.add(premium);
- _pullAToken(assetFrom, aToken, initiator, amountToPull, permitSignature);
+ _pullAToken(assetFrom, vars.aToken, initiator, vars.amountToPull, permitSignature);
// Repay flash loan
- IERC20(assetFrom).approve(address(LENDING_POOL), flashLoanDebt);
+ IERC20(assetFrom).safeApprove(address(LENDING_POOL), 0);
+ IERC20(assetFrom).safeApprove(address(LENDING_POOL), vars.flashLoanDebt);
}
/**
@@ -261,4 +277,4 @@ contract UniswapLiquiditySwapAdapter is BaseUniswapAdapter {
useEthPath
);
}
-}
+}
\ No newline at end of file
diff --git a/contracts/adapters/UniswapRepayAdapter.sol b/contracts/adapters/UniswapRepayAdapter.sol
index b5ce12bb..c4e7817e 100644
--- a/contracts/adapters/UniswapRepayAdapter.sol
+++ b/contracts/adapters/UniswapRepayAdapter.sol
@@ -129,7 +129,7 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
);
// Swap collateral for debt asset
- _swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], amountToRepay);
+ _swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], amountToRepay, useEthPath);
} else {
// Pull aTokens from user
_pullAToken(
@@ -141,8 +141,9 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
);
}
- // Repay debt
- IERC20(debtAsset).approve(address(LENDING_POOL), amountToRepay);
+ // Repay debt. Approves 0 first to comply with tokens that implement the anti frontrunning approval fix
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), 0);
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), amountToRepay);
LENDING_POOL.repay(debtAsset, amountToRepay, debtRateMode, msg.sender);
}
@@ -171,8 +172,9 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
) internal {
DataTypes.ReserveData memory collateralReserveData = _getReserveData(collateralAsset);
- // Repay debt
- IERC20(debtAsset).approve(address(LENDING_POOL), amount);
+ // Repay debt. Approves for 0 first to comply with tokens that implement the anti frontrunning approval fix.
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), 0);
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), amount);
uint256 repaidAmount = IERC20(debtAsset).balanceOf(address(this));
LENDING_POOL.repay(debtAsset, amount, rateMode, initiator);
repaidAmount = repaidAmount.sub(IERC20(debtAsset).balanceOf(address(this)));
@@ -198,7 +200,7 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
);
// Swap collateral asset to the debt asset
- _swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], neededForFlashLoanDebt);
+ _swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], neededForFlashLoanDebt, useEthPath);
} else {
// Pull aTokens from user
_pullAToken(
@@ -210,8 +212,9 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
);
}
- // Repay flash loan
- IERC20(debtAsset).approve(address(LENDING_POOL), amount.add(premium));
+ // Repay flashloan. Approves for 0 first to comply with tokens that implement the anti frontrunning approval fix.
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), 0);
+ IERC20(debtAsset).safeApprove(address(LENDING_POOL), amount.add(premium));
}
/**
@@ -253,4 +256,4 @@ contract UniswapRepayAdapter is BaseUniswapAdapter {
useEthPath
);
}
-}
+}
\ No newline at end of file