41 lines
1.2 KiB
Solidity
41 lines
1.2 KiB
Solidity
// SPDX-License-Identifier: MIT
|
|
// OpenZeppelin Contracts v4.4.0 (metatx/ERC2771Context.sol)
|
|
|
|
pragma solidity ^0.8.0;
|
|
|
|
import "../utils/Context.sol";
|
|
|
|
/**
|
|
* @dev Context variant with ERC2771 support.
|
|
*/
|
|
abstract contract ERC2771Context is Context {
|
|
address private _trustedForwarder;
|
|
|
|
constructor(address trustedForwarder) {
|
|
_trustedForwarder = trustedForwarder;
|
|
}
|
|
|
|
function isTrustedForwarder(address forwarder) public view virtual returns (bool) {
|
|
return forwarder == _trustedForwarder;
|
|
}
|
|
|
|
function _msgSender() internal view virtual override returns (address sender) {
|
|
if (isTrustedForwarder(msg.sender)) {
|
|
// The assembly code is more direct than the Solidity version using `abi.decode`.
|
|
assembly {
|
|
sender := shr(96, calldataload(sub(calldatasize(), 20)))
|
|
}
|
|
} else {
|
|
return super._msgSender();
|
|
}
|
|
}
|
|
|
|
function _msgData() internal view virtual override returns (bytes calldata) {
|
|
if (isTrustedForwarder(msg.sender)) {
|
|
return msg.data[:msg.data.length - 20];
|
|
} else {
|
|
return super._msgData();
|
|
}
|
|
}
|
|
}
|