Files
tycho-execution/foundry/src/Dispatcher.sol
Diana Carvalho f91b101a94 fix: Prevent multiple callbacks
After a callback is performed, the executor address transient storage is set to 0 so that multiple callbacks can't be performed for the same swap

--- don't change below this line ---
ENG-4411 Took 22 minutes
2025-04-09 13:39:12 +01:00

119 lines
3.5 KiB
Solidity

// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.26;
import "@interfaces/IExecutor.sol";
import "@interfaces/ICallback.sol";
error Dispatcher__UnapprovedExecutor();
error Dispatcher__NonContractExecutor();
error Dispatcher__InvalidDataLength();
/**
* @title Dispatcher - Dispatch execution to external contracts
* @author PropellerHeads Devs
* @dev Provides the ability to delegate execution of swaps to external
* contracts. This allows dynamically adding new supported protocols
* without needing to upgrade any contracts. External contracts will
* be called using delegatecall so they can share state with the main
* contract if needed.
*
* Note: Executor contracts need to implement the IExecutor interface unless
* an alternate selector is specified.
*/
contract Dispatcher {
mapping(address => bool) public executors;
event ExecutorSet(address indexed executor);
event ExecutorRemoved(address indexed executor);
/**
* @dev Adds or replaces an approved executor contract address if it is a
* contract.
* @param target address of the executor contract
*/
function _setExecutor(address target) internal {
if (target.code.length == 0) {
revert Dispatcher__NonContractExecutor();
}
executors[target] = true;
emit ExecutorSet(target);
}
/**
* @dev Removes an approved executor contract address
* @param target address of the executor contract
*/
function _removeExecutor(address target) internal {
delete executors[target];
emit ExecutorRemoved(target);
}
/**
* @dev Calls an executor, assumes swap.protocolData contains
* protocol-specific data required by the executor.
*/
// slither-disable-next-line delegatecall-loop,assembly
function _callExecutor(
address executor,
uint256 amount,
bytes calldata data
) internal returns (uint256 calculatedAmount) {
if (!executors[executor]) {
revert Dispatcher__UnapprovedExecutor();
}
assembly {
tstore(0, executor)
}
// slither-disable-next-line controlled-delegatecall,low-level-calls
(bool success, bytes memory result) = executor.delegatecall(
abi.encodeWithSelector(IExecutor.swap.selector, amount, data)
);
if (!success) {
revert(
string(
result.length > 0
? result
: abi.encodePacked("Execution failed")
)
);
}
calculatedAmount = abi.decode(result, (uint256));
}
// slither-disable-next-line assembly
function _handleCallback(bytes calldata data) internal {
address executor;
assembly {
executor := tload(0)
}
if (!executors[executor]) {
revert Dispatcher__UnapprovedExecutor();
}
// slither-disable-next-line controlled-delegatecall,low-level-calls
(bool success, bytes memory result) = executor.delegatecall(
abi.encodeWithSelector(ICallback.handleCallback.selector, data)
);
if (!success) {
revert(
string(
result.length > 0
? result
: abi.encodePacked("Callback failed")
)
);
}
// to prevent multiple callbacks
assembly {
tstore(0, 0)
}
}
}