Supporting AugustusSwapper's utility functions for singleSwaps #240
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juniset
reviewed
Apr 28, 2021
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| function isValid(address /*_wallet*/, address _spender, address _to, bytes calldata _data) external view override returns (bool valid) { | ||
| // disable ETH transfer | ||
| if (_data.length < 4) { |
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Wallets should be able to deposit ETH via the fallback function so we should accept calls where _data.length == 0.
juniset
reviewed
Apr 28, 2021
| @@ -269,14 +280,49 @@ contract ParaswapFilter is BaseFilter { | |||
| uint256 exchangeDataOffset = 36 + abi.decode(_data[196:228], (uint256)); | |||
| address[] memory spenders = new address[](_callees.length); | |||
| bytes[] memory allData = new bytes[](_callees.length); | |||
| for(uint256 i = 0; i < _callees.length; i++) { | |||
| uint256 i; | |||
| while(i < _callees.length) { | |||
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I think this doesn't work as you are looping over callees.length but you are reducing the length if the callee is augustus so you might never reach the last callee. Also you are not incrementing i when you reduce the size of callees so you will check the same callee twice. Maybe I'm wrong but it's just a sign that this logic is too complicated.
A simpler version of the same logic that I find simpler to read is
function hasAuthorisedCallees(
address _augustus,
address[] memory _callees,
uint256[] memory _startIndexes,
bytes calldata _data
)
internal
view
returns (bool)
{
// _data = {sig:4}{six params:192}{exchangeDataOffset:32}{...}
// we add 4+32=36 to the offset to skip the method sig and the size of the exchangeData array
uint256 exchangeDataOffset = 36 + abi.decode(_data[196:228], (uint256));
address[] memory to = new address[](_callees.length);
address[] memory spenders = new address[](_callees.length);
bytes[] memory allData = new bytes[](_callees.length);
uint256 i;
while(i < _callees.length) {
bytes calldata slicedExchangeData = _data[exchangeDataOffset+_startIndexes[i] : exchangeDataOffset+_startIndexes[i+1]];
if (_callees[i] == _augustus) {
if (slicedExchangeData.length >= 4 && getMethod(slicedExchangeData) == WITHDRAW_ALL_WETH) {
uint newLength = _callees.length - 1;
// solhint-disable-next-line no-inline-assembly
assembly {
mstore(to, newLength)
mstore(spenders, newLength)
mstore(allData, newLength)
}
} else {
return false;
}
} else {
to[i] = _callees[i];
allData[i] = slicedExchangeData;
spenders[i] = Utils.recoverSpender(_callees[i], slicedExchangeData);
}
i++;
}
return authoriser.areAuthorised(_augustus, spenders, to, allData);
}
If you agree then we no longer need the CalleeInfo struct and the decodeCalleeData method as we are not hitting a stack too deep error.
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Agreed that using a temporary array for callees is much cleaner
juniset
reviewed
Apr 28, 2021
| @@ -97,6 +97,8 @@ contract ParaswapFilter is BaseFilter { | |||
| bytes4 constant internal MEGASWAP = bytes4(keccak256( | |||
| "megaSwap((address,uint256,uint256,uint256,address,string,bool,(uint256,(address,uint256,(address,address,uint256,bytes,uint256)[])[])[]))" | |||
| )); | |||
| bytes4 constant internal APPROVE = bytes4(keccak256("approve(address,address,uint256)")); | |||
juniset
reviewed
Apr 28, 2021
| @@ -137,6 +138,15 @@ contract ParaswapFilter is BaseFilter { | |||
| bytes32 public immutable uniForkInitCode2; // linkswap | |||
| bytes32 public immutable uniForkInitCode3; // defiswap | |||
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| // Stack Extension for hasAuthorisedCallees() | |||
| struct CalleeInfo { | |||
juniset
approved these changes
Apr 28, 2021
juniset
approved these changes
Apr 28, 2021
|
👌 |
1 similar comment
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julitabarelkowska
approved these changes
Nov 28, 2024
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Supporting AugustusSwapper's utility functions for singleSwaps