Merge branch 'main' of github.com:immutable/zkevm-bridge-contracts in…

…to smr-1935-erc20-withdraw-L1

README.md

@@ -83,9 +83,12 @@ CHILD_GAS_SERVICE_ADDRESS=
 ROOT_CHAIN_NAME="ROOT"
 CHILD_CHAIN_NAME="CHILD"
 ROOT_IMX_ADDRESS=
+INITIAL_IMX_CUMULATIVE_DEPOSIT_LIMIT="0"
 ```
 where `{ROOT,CHILD}_{GATEWAY,GAS_SERVICE}_ADDRESS` refers to the gateway and gas service addresses used by Axelar.
 
+`INITIAL_IMX_CUMULATIVE_DEPOSIT_LIMIT` refers to the cumulative amount of IMX that can be deposited. A value of `0` indicated unlimited.
+
 We can just use dummy gateway/gas service addresses if we only want to test the deployment, and not bridging functionality. If wanting to use dummy addresses, any valid Ethereum address can be used here.
 
 4. Run the deploy script.
@@ -138,6 +141,7 @@ ROOT_GATEWAY_ADDRESS="0x013459EC3E8Aeced878C5C4bFfe126A366cd19E9"
 CHILD_GATEWAY_ADDRESS="0xc7B788E88BAaB770A6d4936cdcCcd5250E1bbAd8"
 ROOT_GAS_SERVICE_ADDRESS="0x28f8B50E1Be6152da35e923602a2641491E71Ed8"
 CHILD_GAS_SERVICE_ADDRESS="0xC573c722e21eD7fadD38A8f189818433e01Ae466"
+INITIAL_IMX_CUMULATIVE_DEPOSIT_LIMIT="0"
 ENVIRONMENT="local"
 ```
 (Note that `{ROOT,CHILD}_PRIVATE_KEY` can be any of the standard localhost private keys that get funded)

script/DeployRootContracts.s.sol

@@ -37,18 +37,17 @@ contract DeployRootContracts is Script {
 
         RootERC20Bridge rootERC20BridgeImplementation = new RootERC20Bridge();
         rootERC20BridgeImplementation.initialize(
-            address(1), address(1), "filler", address(1), address(1), address(1), "filler_child_name"
+            address(1), address(1), "filler", address(1), address(1), address(1), "filler_child_name", 1
         );
         TransparentUpgradeableProxy rootERC20BridgeProxy = new TransparentUpgradeableProxy(
             address(rootERC20BridgeImplementation),
             address(proxyAdmin),
             ""
         );
 
-        // TODO add dummy initialize of implementation contracts!
-
         RootAxelarBridgeAdaptor rootBridgeAdaptorImplementation = new RootAxelarBridgeAdaptor(rootGateway);
         rootBridgeAdaptorImplementation.initialize(address(rootERC20BridgeImplementation), "Filler", address(1));
+
         TransparentUpgradeableProxy rootBridgeAdaptorProxy = new TransparentUpgradeableProxy(
             address(rootBridgeAdaptorImplementation),
             address(proxyAdmin),

script/InitializeRootContracts.s.sol

@@ -25,6 +25,7 @@ struct InitializeRootContractsParams {
     address rootWETHToken;
     string childChainName;
     address rootGasService;
+    uint256 initialIMXCumulativeDepositLimit;
 }
 
 contract InitializeRootContracts is Script {
@@ -40,7 +41,8 @@ contract InitializeRootContracts is Script {
             rootIMXToken: vm.envAddress("ROOT_IMX_ADDRESS"),
             rootWETHToken: vm.envAddress("ROOT_WETH_ADDRESS"),
             childChainName: vm.envString("CHILD_CHAIN_NAME"),
-            rootGasService: vm.envAddress("ROOT_GAS_SERVICE_ADDRESS")
+            rootGasService: vm.envAddress("ROOT_GAS_SERVICE_ADDRESS"),
+            initialIMXCumulativeDepositLimit: vm.envUint("INITIAL_IMX_CUMULATIVE_DEPOSIT_LIMIT")
         });
 
         string[] memory checksumInputs = Utils.getChecksumInputs(params.childBridgeAdaptor);
@@ -59,7 +61,8 @@ contract InitializeRootContracts is Script {
             params.rootChainChildTokenTemplate,
             params.rootIMXToken,
             params.rootWETHToken,
-            params.childChainName
+            params.childChainName,
+            params.initialIMXCumulativeDepositLimit
         );
 
         params.rootBridgeAdaptor.initialize(

src/interfaces/root/IRootERC20Bridge.sol

@@ -43,6 +43,10 @@ interface IRootERC20Bridge {
 }
 
 interface IRootERC20BridgeEvents {
+    /// @notice Emitted when the child chain bridge adaptor is updated.
+    event NewRootBridgeAdaptor(address oldRootBridgeAdaptor, address newRootBridgeAdaptor);
+    /// @notice Emitted when the IMX deposit limit is updated.
+    event NewImxDepositLimit(uint256 oldImxDepositLimit, uint256 newImxDepositLimit);
     /// @notice Emitted when a map token message is sent to the child chain.
     event L1TokenMapped(address indexed rootToken, address indexed childToken);
     /// @notice Emitted when an ERC20 deposit message is sent to the child chain.
@@ -109,4 +113,8 @@ interface IRootERC20BridgeErrors {
     error InvalidSourceChain();
     /// @notice Error when caller is not the root bridge adaptor but should be.
     error NotBridgeAdaptor();
+    /// @notice Error when the total IMX deposit limit is exceeded
+    error ImxDepositLimitExceeded();
+    /// @notice Error when the IMX deposit limit is set below the amount of IMX already deposited
+    error ImxDepositLimitTooLow();
 }

src/root/RootERC20Bridge.sol

@@ -36,6 +36,7 @@ contract RootERC20Bridge is
     /// @dev leave this as the first param for the integration tests
     mapping(address => address) public rootTokenToChildToken;
 
+    uint256 public constant NO_DEPOSIT_LIMIT = 0;
     bytes32 public constant MAP_TOKEN_SIG = keccak256("MAP_TOKEN");
     bytes32 public constant DEPOSIT_SIG = keccak256("DEPOSIT");
     bytes32 public constant WITHDRAW_SIG = keccak256("WITHDRAW");
@@ -56,6 +57,9 @@ contract RootERC20Bridge is
     address public rootWETHToken;
     /// @dev The name of the chain that this bridge is connected to.
     string public childChain;
+    /// @dev The maximum cumulative amount of IMX that can be deposited into the bridge.
+    /// @dev A limit of zero indicates unlimited.
+    uint256 public imxCumulativeDepositLimit;
 
     /**
      * @notice Initilization function for RootERC20Bridge.
@@ -66,6 +70,7 @@ contract RootERC20Bridge is
      * @param newRootIMXToken Address of ERC20 IMX on the root chain.
      * @param newRootWETHToken Address of ERC20 WETH on the root chain.
      * @param newChildChain Name of child chain.
+     * @param newImxCumulativeDepositLimit The cumulative IMX deposit limit.
      * @dev Can only be called once.
      */
     function initialize(
@@ -75,7 +80,8 @@ contract RootERC20Bridge is
         address newChildTokenTemplate,
         address newRootIMXToken,
         address newRootWETHToken,
-        string memory newChildChain
+        string memory newChildChain,
+        uint256 newImxCumulativeDepositLimit
     ) public initializer {
         if (
             newRootBridgeAdaptor == address(0) || newChildERC20Bridge == address(0)
@@ -100,15 +106,41 @@ contract RootERC20Bridge is
         rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
         childBridgeAdaptor = newChildBridgeAdaptor;
         childChain = newChildChain;
+        imxCumulativeDepositLimit = newImxCumulativeDepositLimit;
     }
 
+    /**
+     * @notice Updates the root bridge adaptor.
+     * @param newRootBridgeAdaptor Address of new root bridge adaptor.
+     * @dev Can only be called by owner.
+     */
     function updateRootBridgeAdaptor(address newRootBridgeAdaptor) external onlyOwner {
         if (newRootBridgeAdaptor == address(0)) {
             revert ZeroAddress();
         }
+        emit NewRootBridgeAdaptor(address(rootBridgeAdaptor), newRootBridgeAdaptor);
         rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
     }
 
+    // TODO add updating of child bridge adaptor. Part of SMR-1908
+
+    /**
+     * @notice Updates the IMX deposit limit.
+     * @param newImxCumulativeDepositLimit The new cumulative IMX deposit limit.
+     * @dev Can only be called by owner.
+     * @dev The limit can decrease, but it can never decrease to below the contract's IMX balance.
+     */
+    function updateImxCumulativeDepositLimit(uint256 newImxCumulativeDepositLimit) external onlyOwner {
+        if (
+            newImxCumulativeDepositLimit != NO_DEPOSIT_LIMIT
+                && newImxCumulativeDepositLimit < IERC20Metadata(rootIMXToken).balanceOf(address(this))
+        ) {
+            revert ImxDepositLimitTooLow();
+        }
+        emit NewImxDepositLimit(imxCumulativeDepositLimit, newImxCumulativeDepositLimit);
+        imxCumulativeDepositLimit = newImxCumulativeDepositLimit;
+    }
+
     /**
      * @dev method to receive the ETH back from the WETH contract when it is unwrapped
      */
@@ -267,6 +299,12 @@ contract RootERC20Bridge is
         if (amount == 0) {
             revert ZeroAmount();
         }
+        if (
+            address(rootToken) == rootIMXToken && imxCumulativeDepositLimit != NO_DEPOSIT_LIMIT
+                && IERC20Metadata(rootIMXToken).balanceOf(address(this)) + amount > imxCumulativeDepositLimit
+        ) {
+            revert ImxDepositLimitExceeded();
+        }
 
         // ETH, WETH and IMX do not need to be mapped since it should have been mapped on initialization
         // ETH also cannot be transferred since it was received in the payable function call