1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.2) (crosschain/arbitrum/LibArbitrumL2.sol)
pragma solidity ^0.8.4;
import {IArbSys as ArbitrumL2_Bridge} from "../../vendor/arbitrum/IArbSys.sol";
import "../errors.sol";
/**
* @dev Primitives for cross-chain aware contracts for
* https://arbitrum.io/[Arbitrum].
*
* This version should only be used on L2 to process cross-chain messages
* originating from L1. For the other side, use {LibArbitrumL1}.
*/
library LibArbitrumL2 {
/**
* @dev Returns whether the current function call is the result of a
* cross-chain message relayed by `arbsys`.
*/
address public constant ARBSYS = 0x0000000000000000000000000000000000000064;
function isCrossChain(address arbsys) internal view returns (bool) {
return ArbitrumL2_Bridge(arbsys).wasMyCallersAddressAliased();
}
/**
* @dev Returns the address of the sender that triggered the current
* cross-chain message through `arbsys`.
*
* NOTE: {isCrossChain} should be checked before trying to recover the
* sender, as it will revert with `NotCrossChainCall` if the current
* function call is not the result of a cross-chain message.
*/
function crossChainSender(address arbsys) internal view returns (address) {
if (!isCrossChain(arbsys)) revert NotCrossChainCall();
return ArbitrumL2_Bridge(arbsys).myCallersAddressWithoutAliasing();
}
}