hyperlane-monorepo/solidity/contracts/isms/routing/AbstractRoutingIsm.sol

// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.8.0;

// ============ Internal Imports ============
import {IInterchainSecurityModule} from "../../interfaces/IInterchainSecurityModule.sol";
import {IRoutingIsm} from "../../interfaces/isms/IRoutingIsm.sol";

/**
 * @title RoutingIsm
 */
abstract contract AbstractRoutingIsm is IRoutingIsm {
    // ============ Constants ============

    uint8 public constant moduleType =
        uint8(IInterchainSecurityModule.Types.ROUTING);

    // ============ Virtual Functions ============
    // ======= OVERRIDE THESE TO IMPLEMENT =======

    /**
     * @notice Returns the ISM responsible for verifying _message
     * @dev Can change based on the content of _message
     * @param _message Formatted Hyperlane message (see Message.sol).
     * @return module The ISM to use to verify _message
     */
    function route(bytes calldata _message)
        public
        view
        virtual
        returns (IInterchainSecurityModule);

    // ============ Public Functions ============

    /**
     * @notice Routes _metadata and _message to the correct ISM
     * @param _metadata ABI encoded module metadata
     * @param _message Formatted Hyperlane message (see Message.sol).
     */
    function verify(bytes calldata _metadata, bytes calldata _message)
        public
        returns (bool)
    {
        return route(_message).verify(_metadata, _message);
    }
}