Chain exit: add support for upgrades and ownership transfer to the minimal proxy implementation

src/DeployChain.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.15;
 
+import {ResolvingProxyFactory} from "./ResolvingProxyFactory.sol";
 import {Portal} from "./Portal.sol";
 import {OutputOracle} from "./OutputOracle.sol";
 import {SystemConfigOwnable} from "./SystemConfigOwnable.sol";
@@ -101,13 +102,13 @@ contract DeployChain {
     function deployAddresses(uint256 chainID) external view returns (DeployAddresses memory) {
         bytes32 salt = keccak256(abi.encodePacked(chainID));
         return DeployAddresses({
-            l2OutputOracle: proxyAddress(l2OutputOracle, salt),
-            systemConfig: proxyAddress(systemConfig, salt),
-            optimismPortal: proxyAddress(optimismPortal, salt),
-            l1CrossDomainMessenger: proxyAddress(l1CrossDomainMessenger, salt),
-            l1StandardBridge: proxyAddress(l1StandardBridge, salt),
-            l1ERC721Bridge: proxyAddress(l1ERC721Bridge, salt),
-            optimismMintableERC20Factory: proxyAddress(optimismMintableERC20Factory, salt)
+            l2OutputOracle: ResolvingProxyFactory.proxyAddress(l2OutputOracle, proxyAdmin, salt),
+            systemConfig: ResolvingProxyFactory.proxyAddress(systemConfig, proxyAdmin, salt),
+            optimismPortal: ResolvingProxyFactory.proxyAddress(optimismPortal, proxyAdmin, salt),
+            l1CrossDomainMessenger: ResolvingProxyFactory.proxyAddress(l1CrossDomainMessenger, proxyAdmin, salt),
+            l1StandardBridge: ResolvingProxyFactory.proxyAddress(l1StandardBridge, proxyAdmin, salt),
+            l1ERC721Bridge: ResolvingProxyFactory.proxyAddress(l1ERC721Bridge, proxyAdmin, salt),
+            optimismMintableERC20Factory: ResolvingProxyFactory.proxyAddress(optimismMintableERC20Factory, proxyAdmin, salt)
         });
     }
 
@@ -149,13 +150,13 @@ contract DeployChain {
     function setupProxies(uint256 chainID) internal returns (DeployAddresses memory) {
         bytes32 salt = keccak256(abi.encodePacked(chainID));
         return DeployAddresses({
-            l2OutputOracle: setupProxy(l2OutputOracle, salt),
-            systemConfig: setupProxy(systemConfig, salt),
-            optimismPortal: setupProxy(optimismPortal, salt),
-            l1CrossDomainMessenger: setupProxy(l1CrossDomainMessenger, salt),
-            l1StandardBridge: setupProxy(l1StandardBridge, salt),
-            l1ERC721Bridge: setupProxy(l1ERC721Bridge, salt),
-            optimismMintableERC20Factory: setupProxy(optimismMintableERC20Factory, salt)
+            l2OutputOracle: ResolvingProxyFactory.setupProxy(l2OutputOracle, proxyAdmin, salt),
+            systemConfig: ResolvingProxyFactory.setupProxy(systemConfig, proxyAdmin, salt),
+            optimismPortal: ResolvingProxyFactory.setupProxy(optimismPortal, proxyAdmin, salt),
+            l1CrossDomainMessenger: ResolvingProxyFactory.setupProxy(l1CrossDomainMessenger, proxyAdmin, salt),
+            l1StandardBridge: ResolvingProxyFactory.setupProxy(l1StandardBridge, proxyAdmin, salt),
+            l1ERC721Bridge: ResolvingProxyFactory.setupProxy(l1ERC721Bridge, proxyAdmin, salt),
+            optimismMintableERC20Factory: ResolvingProxyFactory.setupProxy(optimismMintableERC20Factory, proxyAdmin, salt)
         });
     }
 
@@ -264,39 +265,4 @@ contract DeployChain {
             gasPayingToken: gasToken
         });
     }
-
-    function setupProxy(address proxy, bytes32 salt) internal returns (address instance) {
-        address _proxyAdmin = proxyAdmin;
-        /// @solidity memory-safe-assembly
-        assembly {
-            let ptr := mload(0x40)
-            mstore(ptr, 0x60678060095f395ff363204e1c7a60e01b5f5273000000000000000000000000)
-            mstore(add(ptr, 0x14), shl(0x60, proxy))
-            mstore(add(ptr, 0x28), 0x6004525f5f60245f730000000000000000000000000000000000000000000000)
-            mstore(add(ptr, 0x31), shl(0x60, _proxyAdmin))
-            mstore(add(ptr, 0x45), 0x5afa3d5f5f3e3d60201416604d573d5ffd5b5f5f365f5f51365f5f375af43d5f)
-            mstore(add(ptr, 0x65), 0x5f3e5f3d91606557fd5bf3000000000000000000000000000000000000000000)
-            instance := create2(0, ptr, 0x70, salt)
-        }
-        require(instance != address(0), "Proxy: create2 failed");
-    }
-
-    function proxyAddress(address proxy, bytes32 salt) internal view returns (address predicted) {
-        address _proxyAdmin = proxyAdmin;
-        address deployer = address(this);
-        /// @solidity memory-safe-assembly
-        assembly {
-            let ptr := mload(0x40)
-            mstore(ptr, 0x60678060095f395ff363204e1c7a60e01b5f5273000000000000000000000000)
-            mstore(add(ptr, 0x14), shl(0x60, proxy))
-            mstore(add(ptr, 0x28), 0x6004525f5f60245f730000000000000000000000000000000000000000000000)
-            mstore(add(ptr, 0x31), shl(0x60, _proxyAdmin))
-            mstore(add(ptr, 0x45), 0x5afa3d5f5f3e3d60201416604d573d5ffd5b5f5f365f5f51365f5f375af43d5f)
-            mstore(add(ptr, 0x65), 0x5f3e5f3d91606557fd5bf3ff0000000000000000000000000000000000000000)
-            mstore(add(ptr, 0x71), shl(0x60, deployer))
-            mstore(add(ptr, 0x85), salt)
-            mstore(add(ptr, 0xa5), keccak256(ptr, 0x70))
-            predicted := keccak256(add(ptr, 0x70), 0x55)
-        }
-    }
 }

src/ResolvingProxy.sol

@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.15;
+
+// The ProxyAdmin contract conforms to this interface.
+interface IResolver {
+    function getProxyImplementation(address _proxy) external view returns (address);
+}
+
+/// @notice ResolvingProxy is a modification of the op-stack Proxy contract that allows for
+///         proxying a proxy. This is useful to have a central upgradable proxy that this
+///         contract can point to, but also support detaching this proxy so it can have its
+///         own implementation.
+/// @dev Only proxies that are owned by a ProxyAdmin can be proxied by this contract,
+///      because it calls getProxyImplementation() on the ProxyAdmin to retrieve the
+///      implementation address.
+/// @dev This contract is based on the EIP-1967 transparent proxy standard. It is slightly
+///      simplified in that it doesn't emit logs for implementation and admin changes. This
+///      is to simplify the assembly implementation provided in ResolvingProxyFactory.
+contract ResolvingProxy {
+    /// @notice The storage slot that holds the address of a proxy implementation.
+    /// @dev `bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)`
+    bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
+
+    /// @notice The storage slot that holds the address of the owner.
+    /// @dev `bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1)`
+    bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
+
+    /// @notice A modifier that reverts if not called by the owner or by address(0) to allow
+    ///         eth_call to interact with this proxy without needing to use low-level storage
+    ///         inspection. We assume that nobody is able to trigger calls from address(0) during
+    ///         normal EVM execution.
+    modifier proxyCallIfNotAdmin() {
+        if (msg.sender == _getAdmin() || msg.sender == address(0)) {
+            _;
+        } else {
+            // This WILL halt the call frame on completion.
+            _doProxyCall();
+        }
+    }
+
+    /// @notice Sets the initial admin during contract deployment. Admin address is stored at the
+    ///         EIP-1967 admin storage slot so that accidental storage collision with the
+    ///         implementation is not possible.
+    /// @param _admin Address of the initial contract admin. Admin has the ability to access the
+    ///               transparent proxy interface.
+    constructor(address _implementation, address _admin) {
+        _setImplementation(_implementation);
+        _setAdmin(_admin);
+    }
+
+    receive() external payable {
+        // Proxy call by default.
+        _doProxyCall();
+    }
+
+    fallback() external payable {
+        // Proxy call by default.
+        _doProxyCall();
+    }
+
+    /// @notice Gets the owner of the proxy contract.
+    /// @return Owner address.
+    function admin() external virtual proxyCallIfNotAdmin returns (address) {
+        return _getAdmin();
+    }
+
+    /// @notice Changes the owner of the proxy contract. Only callable by the owner.
+    /// @param _admin New owner of the proxy contract.
+    function changeAdmin(address _admin) external virtual proxyCallIfNotAdmin {
+        _setAdmin(_admin);
+    }
+
+    //// @notice Queries the implementation address.
+    /// @return Implementation address.
+    function implementation() external virtual proxyCallIfNotAdmin returns (address) {
+        return _getImplementation();
+    }
+
+    /// @notice Set the implementation contract address. The code at the given address will execute
+    ///         when this contract is called.
+    /// @param _implementation Address of the implementation contract.
+    function upgradeTo(address _implementation) external virtual proxyCallIfNotAdmin {
+        _setImplementation(_implementation);
+    }
+
+    /// @notice Set the implementation and call a function in a single transaction. Useful to ensure
+    ///         atomic execution of initialization-based upgrades.
+    /// @param _implementation Address of the implementation contract.
+    /// @param _data           Calldata to delegatecall the new implementation with.
+    function upgradeToAndCall(address _implementation, bytes calldata _data)
+        external
+        payable
+        proxyCallIfNotAdmin
+        returns (bytes memory)
+    {
+        _setImplementation(_implementation);
+        _implementation = _resolveImplementation();
+        (bool success, bytes memory returndata) = _implementation.delegatecall(_data);
+        require(success, "Proxy: delegatecall to new implementation contract failed");
+        return returndata;
+    }
+
+    function _getImplementation() internal view returns (address) {
+        address impl;
+        bytes32 proxyImplementation = IMPLEMENTATION_SLOT;
+        assembly {
+            impl := sload(proxyImplementation)
+        }
+        return impl;
+    }
+
+    function _setImplementation(address _implementation) internal {
+        bytes32 proxyImplementation = IMPLEMENTATION_SLOT;
+        assembly {
+            sstore(proxyImplementation, _implementation)
+        }
+    }
+
+    function _getAdmin() internal view returns (address) {
+        address owner;
+        bytes32 proxyOwner = ADMIN_SLOT;
+        assembly {
+            owner := sload(proxyOwner)
+        }
+        return owner;
+    }
+
+    function _setAdmin(address _admin) internal {
+        bytes32 proxyOwner = ADMIN_SLOT;
+        assembly {
+            sstore(proxyOwner, _admin)
+        }
+    }
+
+    function _doProxyCall() internal {
+        address impl = _resolveImplementation();
+        assembly {
+            calldatacopy(0x0, 0x0, calldatasize())
+            let success := delegatecall(gas(), impl, 0x0, calldatasize(), 0x0, 0x0)
+            returndatacopy(0x0, 0x0, returndatasize())
+            if iszero(success) { revert(0x0, returndatasize()) }
+            return(0x0, returndatasize())
+        }
+    }
+
+    function _resolveImplementation() internal view returns (address) {
+        address proxy = _getImplementation();
+        bytes memory data = abi.encodeCall(IResolver.getProxyImplementation, (proxy));
+        (bool success, bytes memory returndata) = _getAdmin().staticcall(data);
+        if (success && returndata.length == 0x20) {
+            return abi.decode(returndata, (address));
+        }
+        return proxy;
+    }
+}

src/ResolvingProxyFactory.sol

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.15;
+
+import {ResolvingProxy} from "./ResolvingProxy.sol";
+
+/// @title ResolvingProxyFactory
+/// @notice ResolvingProxyFactory is a factory contract that creates ResolvingProxy instances.
+/// @dev The setupProxy / proxyAddress functions provide a smaller assembly-based ResolvingProxy
+///      implementation that is more gas efficient to deploy and operate than the solidity
+///      ResolvingProxy implementation.
+library ResolvingProxyFactory {
+    function setupProxy(address proxy, address admin, bytes32 salt) internal returns (address instance) {
+        /// @solidity memory-safe-assembly
+        assembly {
+            let ptr := mload(0x40)
+            mstore(ptr, shl(0xC0, 0x600661011c565b73))
+            mstore(add(ptr, 0x8), shl(0x60, proxy))
+            mstore(add(ptr, 0x1c), shl(0xE8, 0x905573))
+            mstore(add(ptr, 0x1f), shl(0x60, admin))
+            mstore(add(ptr, 0x33), 0x905561012580603f5f395ff35f365f600860dd565b8054909180548033143315)
+            mstore(add(ptr, 0x53), 0x171560545760045f5f375f5160e01c8063f851a4401460a25780635c60da1b14)
+            mstore(add(ptr, 0x73), 0x609f5780638f2839701460af5780633659cfe61460ac57634f1ef2861460aa57)
+            mstore(add(ptr, 0x93), 0x5b63204e1c7a60e01b5f52826004525f5f60245f845afa3d5f5f3e3d60201416)
+            mstore(add(ptr, 0xb3), 0x805f510290158402015f875f89895f375f935af43d5f893d60205260205f523e)
+            mstore(add(ptr, 0xd3), 0x5f3d890191609d57fd5bf35b50505b505f5260205ff35b5f5b93915b50506020)
+            mstore(add(ptr, 0xf3), 0x60045f375f518091559160d957903333602060445f375f519560649550506040)
+            mstore(add(ptr, 0x113), 0x96506054565b5f5ff35b7f360894a13ba1a3210667c828492db98dca3e2076cc)
+            mstore(add(ptr, 0x133), 0x3735a920a3ca505d382bbc7fb53127684a568b3173ae13b9f8a6016e243e63b6)
+            mstore(add(ptr, 0x153), shl(0x90, 0xe8ee1178d6a717850b5d61039156))
+            instance := create2(0, ptr, 0x161, salt)
+        }
+        require(instance != address(0), "Proxy: create2 failed");
+    }
+
+    function proxyAddress(address proxy, address admin, bytes32 salt) internal view returns (address predicted) {
+        address deployer = address(this);
+        /// @solidity memory-safe-assembly
+        assembly {
+            let ptr := mload(0x40)
+            mstore(ptr, shl(0xC0, 0x600661011c565b73))
+            mstore(add(ptr, 0x8), shl(0x60, proxy))
+            mstore(add(ptr, 0x1c), shl(0xE8, 0x905573))
+            mstore(add(ptr, 0x1f), shl(0x60, admin))
+            mstore(add(ptr, 0x33), 0x905561012580603f5f395ff35f365f600860dd565b8054909180548033143315)
+            mstore(add(ptr, 0x53), 0x171560545760045f5f375f5160e01c8063f851a4401460a25780635c60da1b14)
+            mstore(add(ptr, 0x73), 0x609f5780638f2839701460af5780633659cfe61460ac57634f1ef2861460aa57)
+            mstore(add(ptr, 0x93), 0x5b63204e1c7a60e01b5f52826004525f5f60245f845afa3d5f5f3e3d60201416)
+            mstore(add(ptr, 0xb3), 0x805f510290158402015f875f89895f375f935af43d5f893d60205260205f523e)
+            mstore(add(ptr, 0xd3), 0x5f3d890191609d57fd5bf35b50505b505f5260205ff35b5f5b93915b50506020)
+            mstore(add(ptr, 0xf3), 0x60045f375f518091559160d957903333602060445f375f519560649550506040)
+            mstore(add(ptr, 0x113), 0x96506054565b5f5ff35b7f360894a13ba1a3210667c828492db98dca3e2076cc)
+            mstore(add(ptr, 0x133), 0x3735a920a3ca505d382bbc7fb53127684a568b3173ae13b9f8a6016e243e63b6)
+            mstore(add(ptr, 0x153), shl(0x88, 0xe8ee1178d6a717850b5d61039156ff))
+            mstore(add(ptr, 0x162), shl(0x60, deployer))
+            mstore(add(ptr, 0x176), salt)
+            mstore(add(ptr, 0x196), keccak256(ptr, 0x161))
+            predicted := keccak256(add(ptr, 0x161), 0x55)
+        }
+    }
+
+    function setupExpensiveProxy(address proxy, address admin, bytes32 salt) internal returns (address instance) {
+        return address(new ResolvingProxy{salt: salt}(proxy, admin));
+    }
+
+    function expensiveProxyAddress(address proxy, address admin, bytes32 salt)
+        internal
+        view
+        returns (address predicted)
+    {
+        bytes memory bytecode = abi.encodePacked(type(ResolvingProxy).creationCode, abi.encode(proxy, admin));
+        bytes32 hash = keccak256(abi.encodePacked(bytes1(0xff), address(this), salt, keccak256(bytecode)));
+        return address(uint160(uint256(hash)));
+    }
+}