feat(contracts): add usdc gateway (#426)

Co-authored-by: zimpha <zimpha@users.noreply.github.com>
Co-authored-by: Haichen Shen <shenhaichen@gmail.com>

common/version/version.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-var tag = "v4.2.4"
+var tag = "v4.2.5"
 
 var commit = func() string {
 	if info, ok := debug.ReadBuildInfo(); ok {

contracts/scripts/initialize_l1_erc20_gateway.ts

@@ -25,18 +25,18 @@ async function main() {
   const L2StandardERC20Impl = process.env.L2_SCROLL_STANDARD_ERC20_ADDR!;
   const L2StandardERC20FactoryAddress = process.env.L2_SCROLL_STANDARD_ERC20_FACTORY_ADDR!;
 
-  // if ((await L1StandardERC20Gateway.counterpart()) === constants.AddressZero) {
-  const tx = await L1StandardERC20Gateway.initialize(
-    L2StandardERC20GatewayAddress,
-    L1GatewayRouterAddress,
-    L1ScrollMessengerAddress,
-    L2StandardERC20Impl,
-    L2StandardERC20FactoryAddress
-  );
-  console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
-  const receipt = await tx.wait();
-  console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
-  // }
+  if ((await L1StandardERC20Gateway.counterpart()) === constants.AddressZero) {
+    const tx = await L1StandardERC20Gateway.initialize(
+      L2StandardERC20GatewayAddress,
+      L1GatewayRouterAddress,
+      L1ScrollMessengerAddress,
+      L2StandardERC20Impl,
+      L2StandardERC20FactoryAddress
+    );
+    console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
+    const receipt = await tx.wait();
+    console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
+  }
 }
 
 // We recommend this pattern to be able to use async/await everywhere

contracts/scripts/initialize_l1_gateway_router.ts

@@ -23,16 +23,16 @@ async function main() {
   const L1ScrollMessengerAddress = addressFile.get("L1ScrollMessenger.proxy");
   const L2GatewayRouterAddress = process.env.L2_GATEWAY_ROUTER_PROXY_ADDR!;
 
-  // if ((await L1GatewayRouter.counterpart()) === constants.AddressZero) {
-  const tx = await L1GatewayRouter.initialize(
-    L1StandardERC20GatewayAddress,
-    L2GatewayRouterAddress,
-    L1ScrollMessengerAddress
-  );
-  console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
-  const receipt = await tx.wait();
-  console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
-  // }
+  if ((await L1GatewayRouter.counterpart()) === constants.AddressZero) {
+    const tx = await L1GatewayRouter.initialize(
+      L1StandardERC20GatewayAddress,
+      L2GatewayRouterAddress,
+      L1ScrollMessengerAddress
+    );
+    console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
+    const receipt = await tx.wait();
+    console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
+  }
 }
 
 // We recommend this pattern to be able to use async/await everywhere

contracts/scripts/initialize_l1_messenger.ts

@@ -21,12 +21,12 @@ async function main() {
 
   const ZKRollupAddress = addressFile.get("ZKRollup.proxy");
 
-  // if ((await L1ScrollMessenger.rollup()) === constants.AddressZero) {
-  const tx = await L1ScrollMessenger.initialize(ZKRollupAddress);
-  console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
-  const receipt = await tx.wait();
-  console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
-  // }
+  if ((await L1ScrollMessenger.rollup()) === constants.AddressZero) {
+    const tx = await L1ScrollMessenger.initialize(ZKRollupAddress);
+    console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
+    const receipt = await tx.wait();
+    console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
+  }
 }
 
 // We recommend this pattern to be able to use async/await everywhere

contracts/scripts/initialize_l2_erc20_gateway.ts

@@ -24,17 +24,17 @@ async function main() {
   const L2StandardERC20FactoryAddress = addressFile.get("ScrollStandardERC20Factory");
   const L1StandardERC20GatewayAddress = process.env.L1_STANDARD_ERC20_GATEWAY_PROXY_ADDR!;
 
-  // if ((await L2StandardERC20Gateway.counterpart()) === constants.AddressZero) {
-  const tx = await L2StandardERC20Gateway.initialize(
-    L1StandardERC20GatewayAddress,
-    L2GatewayRouterAddress,
-    L2ScrollMessengerAddress,
-    L2StandardERC20FactoryAddress
-  );
-  console.log("initialize L2StandardERC20Gateway, hash:", tx.hash);
-  const receipt = await tx.wait();
-  console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
-  // }
+  if ((await L2StandardERC20Gateway.counterpart()) === constants.AddressZero) {
+    const tx = await L2StandardERC20Gateway.initialize(
+      L1StandardERC20GatewayAddress,
+      L2GatewayRouterAddress,
+      L2ScrollMessengerAddress,
+      L2StandardERC20FactoryAddress
+    );
+    console.log("initialize L2StandardERC20Gateway, hash:", tx.hash);
+    const receipt = await tx.wait();
+    console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
+  }
 }
 
 // We recommend this pattern to be able to use async/await everywhere

contracts/scripts/initialize_l2_gateway_router.ts

@@ -23,16 +23,16 @@ async function main() {
   const L2ScrollMessengerAddress = addressFile.get("L2ScrollMessenger");
   const L1GatewayRouterAddress = process.env.L1_GATEWAY_ROUTER_PROXY_ADDR!;
 
-  // if ((await L2GatewayRouter.counterpart()) === constants.AddressZero) {
-  const tx = await L2GatewayRouter.initialize(
-    L2StandardERC20GatewayAddress,
-    L1GatewayRouterAddress,
-    L2ScrollMessengerAddress
-  );
-  console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
-  const receipt = await tx.wait();
-  console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
-  // }
+  if ((await L2GatewayRouter.counterpart()) === constants.AddressZero) {
+    const tx = await L2GatewayRouter.initialize(
+      L2StandardERC20GatewayAddress,
+      L1GatewayRouterAddress,
+      L2ScrollMessengerAddress
+    );
+    console.log("initialize L1StandardERC20Gateway, hash:", tx.hash);
+    const receipt = await tx.wait();
+    console.log(`✅ Done, gas used: ${receipt.gasUsed}`);
+  }
 }
 
 // We recommend this pattern to be able to use async/await everywhere

contracts/src/L1/gateways/L1ERC20Gateway.sol

@@ -66,7 +66,7 @@ abstract contract L1ERC20Gateway is IL1ERC20Gateway, IMessageDropCallback, Scrol
         address _to,
         uint256 _amount,
         bytes calldata _data
-    ) external payable override onlyCallByCounterpart nonReentrant {
+    ) external payable virtual override onlyCallByCounterpart nonReentrant {
         _beforeFinalizeWithdrawERC20(_l1Token, _l2Token, _from, _to, _amount, _data);
 
         // @note can possible trigger reentrant call to this contract or messenger,

contracts/src/L1/gateways/usdc/L1USDCGateway.sol

@@ -2,10 +2,176 @@
 
 pragma solidity =0.8.16;
 
-import {L1CustomERC20Gateway} from "../L1CustomERC20Gateway.sol";
+import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
+import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
 
-// solhint-disable no-empty-blocks
+import {IFiatToken} from "../../../interfaces/IFiatToken.sol";
+import {IUSDCBurnableSourceBridge} from "../../../interfaces/IUSDCBurnableSourceBridge.sol";
+import {IL2ERC20Gateway} from "../../../L2/gateways/IL2ERC20Gateway.sol";
+import {IL1ScrollMessenger} from "../../IL1ScrollMessenger.sol";
+import {IL1ERC20Gateway} from "../IL1ERC20Gateway.sol";
 
-contract L1USDCGateway is L1CustomERC20Gateway {
+import {ScrollGatewayBase} from "../../../libraries/gateway/ScrollGatewayBase.sol";
+import {L1ERC20Gateway} from "../L1ERC20Gateway.sol";
 
+/// @title L1USDCGateway
+/// @notice The `L1USDCGateway` contract is used to deposit `USDC` token in layer 1 and
+/// finalize withdraw `USDC` from layer 2, before USDC become native in layer 2.
+contract L1USDCGateway is L1ERC20Gateway, IUSDCBurnableSourceBridge {
+    /*************
+     * Constants *
+     *************/
+
+    /// @notice The address of L1 USDC address.
+    // solhint-disable-next-line var-name-mixedcase
+    address public immutable l1USDC;
+
+    /// @notice The address of L2 USDC address.
+    address public immutable l2USDC;
+
+    /*************
+     * Variables *
+     *************/
+
+    /// @notice The address of caller from Circle.
+    address public circleCaller;
+
+    /// @notice The flag indicates whether USDC deposit is paused.
+    bool public depositPaused;
+
+    /// @notice The flag indicates whether USDC withdrawal is paused.
+    /// @dev This is not necessary to be set `true` since we will set `L2USDCGateway.withdrawPaused` first.
+    ///      This is kept just in case and will be set after all pending messages are relayed.
+    bool public withdrawPaused;
+
+    /// @notice The total amount of bridged USDC in this contract.
+    /// @dev Only deposited USDC will count. Accidentally transferred USDC will be ignored.
+    uint256 public totalBridgedUSDC;
+
+    /***************
+     * Constructor *
+     ***************/
+
+    constructor(address _l1USDC, address _l2USDC) {
+        _disableInitializers();
+
+        l1USDC = _l1USDC;
+        l2USDC = _l2USDC;
+    }
+
+    /// @notice Initialize the storage of L1WETHGateway.
+    /// @param _counterpart The address of L2ETHGateway in L2.
+    /// @param _router The address of L1GatewayRouter.
+    /// @param _messenger The address of L1ScrollMessenger.
+    function initialize(
+        address _counterpart,
+        address _router,
+        address _messenger
+    ) external initializer {
+        require(_router != address(0), "zero router address");
+        ScrollGatewayBase._initialize(_counterpart, _router, _messenger);
+    }
+
+    /*************************
+     * Public View Functions *
+     *************************/
+
+    /// @inheritdoc IL1ERC20Gateway
+    function getL2ERC20Address(address) public view override returns (address) {
+        return l2USDC;
+    }
+
+    /*******************************
+     * Public Restricted Functions *
+     *******************************/
+
+    /// @inheritdoc IUSDCBurnableSourceBridge
+    function burnAllLockedUSDC() external override {
+        require(msg.sender == circleCaller, "only circle caller");
+
+        // @note Only bridged USDC will be burned. We may refund the rest if possible.
+        uint256 _balance = totalBridgedUSDC;
+        totalBridgedUSDC = 0;
+
+        IFiatToken(l1USDC).burn(_balance);
+    }
+
+    /// @notice Update the Circle EOA address.
+    /// @param _caller The address to update.
+    function updateCircleCaller(address _caller) external onlyOwner {
+        circleCaller = _caller;
+    }
+
+    /// @notice Change the deposit pause status of this contract.
+    /// @param _paused The new status, `true` means paused and `false` means not paused.
+    function pauseDeposit(bool _paused) external onlyOwner {
+        depositPaused = _paused;
+    }
+
+    /// @notice Change the withdraw pause status of this contract.
+    /// @param _paused The new status, `true` means paused and `false` means not paused.
+    function pauseWithdraw(bool _paused) external onlyOwner {
+        withdrawPaused = _paused;
+    }
+
+    /**********************
+     * Internal Functions *
+     **********************/
+
+    /// @inheritdoc L1ERC20Gateway
+    function _beforeFinalizeWithdrawERC20(
+        address _l1Token,
+        address _l2Token,
+        address,
+        address,
+        uint256 _amount,
+        bytes calldata
+    ) internal virtual override {
+        require(msg.value == 0, "nonzero msg.value");
+        require(_l1Token == l1USDC, "l1 token not USDC");
+        require(_l2Token == l2USDC, "l2 token not USDC");
+        require(!withdrawPaused, "withdraw paused");
+
+        totalBridgedUSDC -= _amount;
+    }
+
+    /// @inheritdoc L1ERC20Gateway
+    function _beforeDropMessage(
+        address,
+        address,
+        uint256 _amount
+    ) internal virtual override {
+        require(msg.value == 0, "nonzero msg.value");
+        totalBridgedUSDC -= _amount;
+    }
+
+    /// @inheritdoc L1ERC20Gateway
+    function _deposit(
+        address _token,
+        address _to,
+        uint256 _amount,
+        bytes memory _data,
+        uint256 _gasLimit
+    ) internal virtual override nonReentrant {
+        require(_amount > 0, "deposit zero amount");
+        require(_token == l1USDC, "only USDC is allowed");
+        require(!depositPaused, "deposit paused");
+
+        // 1. Transfer token into this contract.
+        address _from;
+        (_from, _amount, _data) = _transferERC20In(_token, _amount, _data);
+        require(_data.length == 0, "call is not allowed");
+        totalBridgedUSDC += _amount;
+
+        // 2. Generate message passed to L2USDCGateway.
+        bytes memory _message = abi.encodeCall(
+            IL2ERC20Gateway.finalizeDepositERC20,
+            (_token, l2USDC, _from, _to, _amount, _data)
+        );
+
+        // 3. Send message to L1ScrollMessenger.
+        IL1ScrollMessenger(messenger).sendMessage{value: msg.value}(counterpart, 0, _message, _gasLimit, _from);
+
+        emit DepositERC20(_token, l2USDC, _from, _to, _amount, _data);
+    }
 }