Add IMX deposit limit

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

@@ -35,15 +35,15 @@ contract DeployRootContracts is Script {
         rootChainChildTokenTemplate.initialize(address(123), "TEMPLATE", "TPT", 18);
 
         RootERC20Bridge rootERC20BridgeImplementation = new RootERC20Bridge();
-        rootERC20BridgeImplementation.initialize(address(1), address(1), "filler", address(1), address(1), address(1));
+        rootERC20BridgeImplementation.initialize(
+            address(1), address(1), "filler", address(1), address(1), address(1), 1
+        );
         TransparentUpgradeableProxy rootERC20BridgeProxy = new TransparentUpgradeableProxy(
             address(rootERC20BridgeImplementation),
             address(proxyAdmin),
             ""
         );
 
-        // TODO add dummy initialize of implementation contracts!
-
         RootAxelarBridgeAdaptor rootBridgeAdaptorImplementation = new RootAxelarBridgeAdaptor();
         rootBridgeAdaptorImplementation.initialize(
             address(rootERC20BridgeImplementation), "Filler", address(1), address(1)

script/InitializeRootContracts.s.sol

@@ -26,6 +26,7 @@ struct InitializeRootContractsParams {
     string childChainName;
     address rootGateway;
     address rootGasService;
+    uint256 initialIMXCumulativeDepositLimit;
 }
 
 contract InitializeRootContracts is Script {
@@ -42,7 +43,8 @@ contract InitializeRootContracts is Script {
             rootWETHToken: vm.envAddress("ROOT_WETH_ADDRESS"),
             childChainName: vm.envString("CHILD_CHAIN_NAME"),
             rootGateway: vm.envAddress("ROOT_GATEWAY_ADDRESS"),
-            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);
@@ -60,7 +62,8 @@ contract InitializeRootContracts is Script {
             childBridgeAdaptorChecksum,
             params.rootChainChildTokenTemplate,
             params.rootIMXToken,
-            params.rootWETHToken
+            params.rootWETHToken,
+            params.initialIMXCumulativeDepositLimit
         );
 
         params.rootBridgeAdaptor.initialize(

src/interfaces/root/IRootERC20Bridge.sol

@@ -35,6 +35,10 @@ 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.
@@ -83,4 +87,8 @@ interface IRootERC20BridgeErrors {
     error BalanceInvariantCheckFailed(uint256 actualBalance, uint256 expectedBalance);
     /// @notice Error when the given child chain bridge adaptor is invalid.
     error InvalidChildERC20BridgeAdaptor();
+    /// @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

@@ -52,6 +52,9 @@ contract RootERC20Bridge is
     address public childETHToken;
     /// @dev The address of the wETH ERC20 token on L1.
     address public rootWETHToken;
+    /// @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.
@@ -61,6 +64,7 @@ contract RootERC20Bridge is
      * @param newChildTokenTemplate Address of child token template to clone.
      * @param newRootIMXToken Address of ERC20 IMX on the root chain.
      * @param newRootWETHToken Address of ERC20 WETH on the root chain.
+     * @param newImxCumulativeDepositLimit The cumulative IMX deposit limit.
      * @dev Can only be called once.
      */
     function initialize(
@@ -69,7 +73,8 @@ contract RootERC20Bridge is
         string memory newChildBridgeAdaptor,
         address newChildTokenTemplate,
         address newRootIMXToken,
-        address newRootWETHToken
+        address newRootWETHToken,
+        uint256 newImxCumulativeDepositLimit
     ) public initializer {
         if (
             newRootBridgeAdaptor == address(0) || newChildERC20Bridge == address(0)
@@ -89,15 +94,38 @@ contract RootERC20Bridge is
         );
         rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
         childBridgeAdaptor = newChildBridgeAdaptor;
+        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 < 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
      */
@@ -227,6 +255,12 @@ contract RootERC20Bridge is
         if (amount == 0) {
             revert ZeroAmount();
         }
+        if (
+            address(rootToken) == rootIMXToken && imxCumulativeDepositLimit != 0
+                && 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

test/integration/root/RootERC20Bridge.t.sol

@@ -20,6 +20,7 @@ contract RootERC20BridgeIntegrationTest is Test, IRootERC20BridgeEvents, IRootAx
     address constant IMX_TOKEN_ADDRESS = address(0xccc);
     address constant NATIVE_ETH = address(0xeee);
     address constant WRAPPED_ETH = address(0xddd);
+    uint256 constant unlimitedDepositLimit = 0;
 
     uint256 constant mapTokenFee = 300;
     uint256 constant depositFee = 200;
@@ -34,8 +35,9 @@ contract RootERC20BridgeIntegrationTest is Test, IRootERC20BridgeEvents, IRootAx
     function setUp() public {
         deployCodeTo("WETH.sol", abi.encode("Wrapped ETH", "WETH"), WRAPPED_ETH);
 
-        (imxToken, token, rootBridge, axelarAdaptor, mockAxelarGateway, axelarGasService) =
-            integrationSetup(CHILD_BRIDGE, CHILD_BRIDGE_ADAPTOR, CHILD_CHAIN_NAME, IMX_TOKEN_ADDRESS, WRAPPED_ETH);
+        (imxToken, token, rootBridge, axelarAdaptor, mockAxelarGateway, axelarGasService) = integrationSetup(
+            CHILD_BRIDGE, CHILD_BRIDGE_ADAPTOR, CHILD_CHAIN_NAME, IMX_TOKEN_ADDRESS, WRAPPED_ETH, unlimitedDepositLimit
+        );
     }
 
     /**

test/unit/root/RootERC20Bridge.t.sol

@@ -27,6 +27,7 @@ contract RootERC20BridgeUnitTest is Test, IRootERC20BridgeEvents, IRootERC20Brid
     address constant WRAPPED_ETH = address(0xddd);
     uint256 constant mapTokenFee = 300;
     uint256 constant depositFee = 200;
+    uint256 constant unlimitedIMXDeposits = 0;
 
     ERC20PresetMinterPauser public token;
     RootERC20Bridge public rootBridge;
@@ -53,7 +54,8 @@ contract RootERC20BridgeUnitTest is Test, IRootERC20BridgeEvents, IRootERC20Brid
             CHILD_BRIDGE_ADAPTOR_STRING,
             address(token),
             IMX_TOKEN,
-            WRAPPED_ETH
+            WRAPPED_ETH,
+            unlimitedIMXDeposits
         );
     }
 
@@ -75,50 +77,112 @@ contract RootERC20BridgeUnitTest is Test, IRootERC20BridgeEvents, IRootERC20Brid
             CHILD_BRIDGE_ADAPTOR_STRING,
             address(token),
             IMX_TOKEN,
-            WRAPPED_ETH
+            WRAPPED_ETH,
+            unlimitedIMXDeposits
         );
     }
 
     function test_RevertIf_InitializeWithAZeroAddressRootAdapter() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(0), address(1), CHILD_BRIDGE_ADAPTOR_STRING, address(1), address(1), address(1));
+        bridge.initialize(
+            address(0),
+            address(1),
+            CHILD_BRIDGE_ADAPTOR_STRING,
+            address(1),
+            address(1),
+            address(1),
+            unlimitedIMXDeposits
+        );
     }
 
     function test_RevertIf_InitializeWithAZeroAddressChildBridge() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(1), address(0), CHILD_BRIDGE_ADAPTOR_STRING, address(1), address(1), address(1));
+        bridge.initialize(
+            address(1),
+            address(0),
+            CHILD_BRIDGE_ADAPTOR_STRING,
+            address(1),
+            address(1),
+            address(1),
+            unlimitedIMXDeposits
+        );
     }
 
     function test_RevertIf_InitializeWithEmptyChildAdapter() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(InvalidChildERC20BridgeAdaptor.selector);
-        bridge.initialize(address(1), address(1), "", address(1), address(1), address(1));
+        bridge.initialize(address(1), address(1), "", address(1), address(1), address(1), unlimitedIMXDeposits);
     }
 
     function test_RevertIf_InitializeWithAZeroAddressTokenTemplate() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(1), address(1), CHILD_BRIDGE_ADAPTOR_STRING, address(0), address(1), address(1));
+        bridge.initialize(
+            address(1),
+            address(1),
+            CHILD_BRIDGE_ADAPTOR_STRING,
+            address(0),
+            address(1),
+            address(1),
+            unlimitedIMXDeposits
+        );
     }
 
     function test_RevertIf_InitializeWithAZeroAddressIMXToken() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(1), address(1), CHILD_BRIDGE_ADAPTOR_STRING, address(1), address(0), address(1));
+        bridge.initialize(
+            address(1),
+            address(1),
+            CHILD_BRIDGE_ADAPTOR_STRING,
+            address(1),
+            address(0),
+            address(1),
+            unlimitedIMXDeposits
+        );
     }
 
     function test_RevertIf_InitializeWithAZeroAddressWETHToken() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(1), address(1), CHILD_BRIDGE_ADAPTOR_STRING, address(1), address(1), address(0));
+        bridge.initialize(
+            address(1),
+            address(1),
+            CHILD_BRIDGE_ADAPTOR_STRING,
+            address(1),
+            address(1),
+            address(0),
+            unlimitedIMXDeposits
+        );
     }
 
     function test_RevertIf_InitializeWithAZeroAddressAll() public {
         RootERC20Bridge bridge = new RootERC20Bridge();
         vm.expectRevert(ZeroAddress.selector);
-        bridge.initialize(address(0), address(0), "", address(0), address(0), address(0));
+        bridge.initialize(address(0), address(0), "", address(0), address(0), address(0), unlimitedIMXDeposits);
+    }
+
+    /**
+     * UPDATE IMX CUMULATIVE DEPOSIT LIMIT
+     */
+    function test_RevertsIf_IMXDepositLimitTooLow() public {
+        uint256 imxCumulativeDepositLimit = 700;
+        uint256 depositAmount = imxCumulativeDepositLimit + 1;
+
+        rootBridge.updateImxCumulativeDepositLimit(imxCumulativeDepositLimit);
+
+        setupDeposit(IMX_TOKEN, rootBridge, mapTokenFee, depositFee, depositAmount, false);
+
+        IERC20Metadata(IMX_TOKEN).approve(address(rootBridge), type(uint256).max);
+
+        rootBridge.updateImxCumulativeDepositLimit(depositAmount);
+
+        rootBridge.deposit{value: depositFee}(IERC20Metadata(IMX_TOKEN), depositAmount);
+
+        vm.expectRevert(ImxDepositLimitTooLow.selector);
+        rootBridge.updateImxCumulativeDepositLimit(imxCumulativeDepositLimit);
     }
 
     /**
@@ -406,6 +470,29 @@ contract RootERC20BridgeUnitTest is Test, IRootERC20BridgeEvents, IRootERC20Brid
      * DEPOSIT TOKEN
      */
 
+    function test_RevertsIf_IMXDepositLimitExceeded() public {
+        uint256 imxCumulativeDepositLimit = 700;
+
+        uint256 amount = 300;
+        setupDeposit(IMX_TOKEN, rootBridge, mapTokenFee, depositFee, amount, false);
+
+        IERC20Metadata(IMX_TOKEN).approve(address(rootBridge), type(uint256).max);
+
+        rootBridge.updateImxCumulativeDepositLimit(imxCumulativeDepositLimit);
+
+        // Valid
+        rootBridge.deposit{value: depositFee}(IERC20Metadata(IMX_TOKEN), amount);
+
+        setupDeposit(IMX_TOKEN, rootBridge, mapTokenFee, depositFee, amount, false);
+        // Valid
+        rootBridge.deposit{value: depositFee}(IERC20Metadata(IMX_TOKEN), amount);
+
+        setupDeposit(IMX_TOKEN, rootBridge, mapTokenFee, depositFee, amount, false);
+        // Invalid
+        vm.expectRevert(ImxDepositLimitExceeded.selector);
+        rootBridge.deposit{value: depositFee}(IERC20Metadata(IMX_TOKEN), amount);
+    }
+
     function test_depositCallsSendMessage() public {
         uint256 amount = 100;
         (, bytes memory predictedPayload) =

test/utils.t.sol

@@ -20,7 +20,8 @@ contract Utils is Test {
         address childBridgeAdaptor,
         string memory childBridgeName,
         address imxTokenAddress,
-        address wethTokenAddress
+        address wethTokenAddress,
+        uint256 imxCumulativeDepositLimit
     )
         public
         returns (
@@ -55,7 +56,8 @@ contract Utils is Test {
             Strings.toHexString(childBridgeAdaptor),
             address(token),
             imxTokenAddress,
-            wethTokenAddress
+            wethTokenAddress,
+            imxCumulativeDepositLimit
         );
 
         axelarAdaptor.initialize(