feat: upgrade bridge to allow for transfer of all token assets

contracts/remappings.txt

@@ -12,3 +12,4 @@ src/universal/=lib/optimism/packages/contracts-bedrock/src/universal/
 src/vendor/=lib/optimism/packages/contracts-bedrock/src/vendor/
 scripts/=lib/optimism/packages/contracts-bedrock/scripts/
 @nitro-validator/=lib/nitro-validator/src/
+src/legacy/=lib/optimism/packages/contracts-bedrock/src/legacy/

contracts/script/DeployPortalWithChainExit.s.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import {Script} from "forge-std/Script.sol";
+import {PortalWithChainExit} from "../src/PortalWithChainExit.sol";
+import {console2 as console} from "forge-std/console2.sol";
+
+contract DeployPortalWithChainExit is Script {
+    function run() public {
+        vm.startBroadcast();
+        PortalWithChainExit portalWithChainExit = new PortalWithChainExit();
+        vm.stopBroadcast();
+        console.log("Deploying PortalWithChainOwnerExit at:", address(portalWithChainExit));
+    }
+}

contracts/src/Portal.sol

@@ -70,6 +70,10 @@ contract Portal is Initializable, ResourceMetering, ISemver {
     ///         It is not safe to trust `ERC20.balanceOf` as it may lie.
     uint256 internal _balance;
 
+    // Owner of the current chain 
+    address public chainOwner;
+
+
     /// @notice Emitted when a transaction is deposited from L1 to L2.
     ///         The parameters of this event are read by the rollup node and used to derive deposit
     ///         transactions on L2.
@@ -90,16 +94,42 @@ contract Portal is Initializable, ResourceMetering, ISemver {
     /// @param success        Whether the withdrawal transaction was successful.
     event WithdrawalFinalized(bytes32 indexed withdrawalHash, bool success);
 
+    /// @notice Emitted when a chain owner is set
+    /// @param chainOwner address of the chain owner
+    event ChainOwnerSet(address chainOwner);
+
+    /// @notice Emitted when the chain owner executes a withdrawal.
+    /// @param recipient The address that received the funds.
+    /// @param token The token address (Constants.ETHER for native ETH).
+    /// @param amount The amount withdrawn.
+    event ChainOwnerExitWithdrawal(address indexed recipient, address indexed token, uint256 amount);
+
     /// @notice Reverts when paused.
     modifier whenNotPaused() {
         if (paused()) revert CallPaused();
         _;
     }
 
+    /// @notice Reverts if caller is not the proxy admin.
+    modifier onlyAdmin() {
+        address admin;
+        bytes32 adminSlot = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
+        assembly {
+            admin := sload(adminSlot)
+        }
+        require(msg.sender == admin, "Portal: caller is not admin");
+        _;
+    }
+
+    modifier onlyChainOwner() {
+        require(msg.sender == chainOwner, "Portal: caller is not chain owner");
+        _;
+    }
+
     /// @notice Semantic version.
-    /// @custom:semver 1.0.0
+    /// @custom:semver 1.1.0
     function version() public pure virtual returns (string memory) {
-        return "1.0.0";
+        return "1.1.0";
     }
 
     /// @notice Constructs the OptimismPortal contract.
@@ -489,6 +519,53 @@ contract Portal is Initializable, ResourceMetering, ISemver {
         );
     }
 
+    function setChainOwner(address _chainOwner) external onlyAdmin {
+        chainOwner = _chainOwner;`
+        emit ChainOwnerSet(chainOwner);
+    }
+
+    /// @notice Allows owner to withdraw the gas paying token held by the portal.
+    ///         Can be called regardless of pause state.
+    /// @param _recipient The address to receive the withdrawn funds.
+    function chainOwnerExitPortalNetworkToken(address _recipient) external onlyChainOwner {
+        chainOwnerExitPortal(address(0), _recipient);
+    }
+
+    /// @notice Allows owner to withdraw all tokens held by the portal.
+    ///         Can be called regardless of pause state.
+    /// @param _asset The token address to withdraw, or address(0) for the gas paying token.
+    /// @param _recipient The address to receive the withdrawn funds.
+    function chainOwnerExitPortal(address _asset, address _recipient) public onlyChainOwner {
+        require(_recipient != address(0), "Portal: zero recipient");
+
+        address token;
+        if (_asset != address(0)) {
+            token = _asset;
+        } else {
+            (token,) = gasPayingToken();
+        }
+
+        uint256 amount;
+        if (token == Constants.ETHER) {
+            amount = address(this).balance;
+            if (amount > 0) {
+                (bool success,) = _recipient.call{value: amount}("");
+                require(success, "Portal: ETH transfer failed");
+            }
+        } else {
+            amount = IERC20(token).balanceOf(address(this));
+            if (amount > 0) {
+                (address gasToken,) = gasPayingToken();
+                if (token == gasToken) {
+                    _balance = 0;
+                }
+                IERC20(token).safeTransfer(_recipient, amount);
+            }
+        }
+
+        emit ChainOwnerExitWithdrawal(_recipient, token, amount);
+    }
+
     /// @notice Determine if a given output is finalized.
     ///         Reverts if the call to l2Oracle.getL2Output reverts.
     ///         Returns a boolean otherwise.
@@ -505,4 +582,4 @@ contract Portal is Initializable, ResourceMetering, ISemver {
     function _isFinalizationPeriodElapsed(uint256 _timestamp) internal view returns (bool) {
         return block.timestamp > _timestamp;
     }
-}
+}