Merge pull request #152 from 1inch/feat/new-integrator-fee-flow

new integrator fees flow + support for eth fees

contracts/FeeBank.sol

@@ -19,15 +19,15 @@ contract FeeBank is IFeeBank, Ownable {
 
     error ZeroAddress();
 
-    IERC20 private immutable _TOKEN;
+    IERC20 private immutable _FEE_TOKEN;
     IFeeBankCharger private immutable _CHARGER;
 
     mapping(address account => uint256 availableCredit) private _accountDeposits;
 
-    constructor(IFeeBankCharger charger_, IERC20 inch_, address owner_) Ownable(owner_) {
-        if (address(inch_) == address(0)) revert ZeroAddress();
-        _CHARGER = charger_;
-        _TOKEN = inch_;
+    constructor(IFeeBankCharger charger, IERC20 feeToken, address owner) Ownable(owner) {
+        if (address(feeToken) == address(0)) revert ZeroAddress();
+        _CHARGER = charger;
+        _FEE_TOKEN = feeToken;
     }
 
     /**
@@ -66,7 +66,7 @@ contract FeeBank is IFeeBank, Ownable {
         uint256 amount,
         bytes calldata permit
     ) public returns (uint256) {
-        _TOKEN.safePermit(permit);
+        _FEE_TOKEN.safePermit(permit);
         return _depositFor(account, amount);
     }
 
@@ -100,14 +100,14 @@ contract FeeBank is IFeeBank, Ownable {
                 totalAccountFees += accountDeposit - availableCredit_;  // overflow is impossible due to checks in FeeBankCharger
             }
         }
-        _TOKEN.safeTransfer(msg.sender, totalAccountFees);
+        _FEE_TOKEN.safeTransfer(msg.sender, totalAccountFees);
     }
 
     function _depositFor(address account, uint256 amount) internal returns (uint256 totalAvailableCredit) {
         if (account == address(0)) revert ZeroAddress();
-        _TOKEN.safeTransferFrom(msg.sender, address(this), amount);
+        _FEE_TOKEN.safeTransferFrom(msg.sender, address(this), amount);
         unchecked {
-            _accountDeposits[account] += amount;  // overflow is impossible due to limited _TOKEN supply
+            _accountDeposits[account] += amount;  // overflow is impossible due to limited _FEE_TOKEN supply
         }
         totalAvailableCredit = _CHARGER.increaseAvailableCredit(account, amount);
     }
@@ -117,6 +117,6 @@ contract FeeBank is IFeeBank, Ownable {
         unchecked {
             _accountDeposits[msg.sender] -= amount;  // underflow is impossible due to checks in FeeBankCharger
         }
-        _TOKEN.safeTransfer(account, amount);
+        _FEE_TOKEN.safeTransfer(account, amount);
     }
 }

contracts/FeeBankCharger.sol

@@ -29,8 +29,8 @@ contract FeeBankCharger is IFeeBankCharger {
         _;
     }
 
-    constructor(IERC20 token) {
-        FEE_BANK = new FeeBank(this, token, msg.sender);
+    constructor(IERC20 feeToken) {
+        FEE_BANK = new FeeBank(this, feeToken, msg.sender);
     }
 
     /**

contracts/Settlement.sol

@@ -14,7 +14,9 @@ import { SimpleSettlement } from "./SimpleSettlement.sol";
 contract Settlement is SimpleSettlement {
     error InvalidPriorityFee();
 
-    constructor(address limitOrderProtocol, IERC20 token) SimpleSettlement(limitOrderProtocol, token) {}
+    constructor(address limitOrderProtocol, IERC20 feeToken, address weth, address owner)
+        SimpleSettlement(limitOrderProtocol, feeToken, weth, owner)
+    {}
 
     function _postInteraction(
         IOrderMixin.Order calldata order,

contracts/SimpleSettlement.sol

@@ -3,13 +3,13 @@
 pragma solidity 0.8.23;
 
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
 import { IOrderMixin } from "@1inch/limit-order-protocol-contract/contracts/interfaces/IOrderMixin.sol";
 import { BaseExtension } from "./extensions/BaseExtension.sol";
 import { IntegratorFeeExtension } from "./extensions/IntegratorFeeExtension.sol";
 import { ResolverFeeExtension } from "./extensions/ResolverFeeExtension.sol";
 import { WhitelistExtension } from "./extensions/WhitelistExtension.sol";
 
-
 /**
  * @title Simple Settlement contract
  * @notice Contract to execute limit orders settlement, created by Fusion mode.
@@ -18,9 +18,16 @@ contract SimpleSettlement is WhitelistExtension, ResolverFeeExtension, Integrato
     /**
      * @notice Initializes the contract.
      * @param limitOrderProtocol The limit order protocol contract.
-     * @param token The token to charge protocol fees in.
+     * @param feeToken The token to charge protocol fees in.
+     * @param weth The WETH address.
+     * @param owner The owner of the contract.
      */
-    constructor(address limitOrderProtocol, IERC20 token) BaseExtension(limitOrderProtocol) ResolverFeeExtension(token) {}
+    constructor(address limitOrderProtocol, IERC20 feeToken, address weth, address owner)
+        BaseExtension(limitOrderProtocol)
+        ResolverFeeExtension(feeToken)
+        IntegratorFeeExtension(weth)
+        Ownable(owner)
+    {}
 
     function _postInteraction(
         IOrderMixin.Order calldata order,

contracts/extensions/ExtensionLib.sol

@@ -9,6 +9,7 @@ pragma solidity ^0.8.0;
 library ExtensionLib {
     bytes1 private constant _RESOLVER_FEE_FLAG = 0x01;
     bytes1 private constant _INTEGRATOR_FEE_FLAG = 0x02;
+    bytes1 private constant _CUSTOM_RECEIVER_FLAG = 0x04;
     uint256 private constant _WHITELIST_SHIFT = 3;
 
     /**
@@ -29,6 +30,15 @@ library ExtensionLib {
         return extraData[extraData.length - 1] & _INTEGRATOR_FEE_FLAG == _INTEGRATOR_FEE_FLAG;
     }
 
+    /**
+     * @notice Checks if the custom receiver is enabled
+     * @param extraData Data to be processed in the extension
+     * @return True if the custom receiver is specified
+     */
+    function hasCustomReceiver(bytes calldata extraData) internal pure returns (bool) {
+        return extraData[extraData.length - 1] & _CUSTOM_RECEIVER_FLAG == _CUSTOM_RECEIVER_FLAG;
+    }
+
     /**
      * @notice Gets the number of resolvers in the whitelist
      * @param extraData Data to be processed in the extension

contracts/extensions/IntegratorFeeExtension.sol

@@ -3,28 +3,51 @@
 pragma solidity 0.8.23;
 
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
 import { IOrderMixin } from "@1inch/limit-order-protocol-contract/contracts/interfaces/IOrderMixin.sol";
+import { MakerTraits, MakerTraitsLib } from "@1inch/limit-order-protocol-contract/contracts/libraries/MakerTraitsLib.sol";
 import { SafeERC20 } from "@1inch/solidity-utils/contracts/libraries/SafeERC20.sol";
 import { Address, AddressLib } from "@1inch/solidity-utils/contracts/libraries/AddressLib.sol";
+import { UniERC20 } from "@1inch/solidity-utils/contracts/libraries/UniERC20.sol";
 import { BaseExtension } from "./BaseExtension.sol";
 import { ExtensionLib } from "./ExtensionLib.sol";
 
 /**
  * @title Integrator Fee Extension
  * @notice Abstract contract designed to integrate fee processing within the post-interaction phase of order execution.
  */
-abstract contract IntegratorFeeExtension is BaseExtension {
+abstract contract IntegratorFeeExtension is BaseExtension, Ownable {
     using SafeERC20 for IERC20;
     using AddressLib for Address;
     using ExtensionLib for bytes;
+    using MakerTraitsLib for MakerTraits;
+    using UniERC20 for IERC20;
 
-    uint256 private constant _TAKING_FEE_BASE = 1e9;
+    /**
+     * @dev Eth transfer failed. The target fallback may have reverted.
+     */
+    error EthTransferFailed();
+
+    /// @dev Allows fees in range [1e-5, 0.65535]
+    uint256 private constant _FEE_BASE = 1e5;
+
+    address private immutable _WETH;
+
+    constructor(address weth) {
+        _WETH = weth;
+    }
+
+    /**
+     * @notice Fallback function to receive ETH.
+     */
+    receive() external payable {}
 
     /**
      * @param extraData Structured data of length n bytes, segmented as follows:
-     * [0:20]  - Integrator address.
-     * [20:24] - Integration fee information.
-     * [24:n]  - ExtraData for other extensions, not utilized by this integration fee extension.
+     * [0:2]   - Fee percentage in basis points.
+     * [2:22]  - Integrator address.
+     * [22:42] - Custom receiver address.
+     * [42:n]  - ExtraData for other extensions, not utilized by this integration fee extension.
      * [n] - Bitmap indicating usage flags, where `xxxx xx1x` signifies integration fee usage. Other bits in this bitmap are not used by this extension.
      */
     function _postInteraction(
@@ -38,13 +61,51 @@ abstract contract IntegratorFeeExtension is BaseExtension {
         bytes calldata extraData
     ) internal virtual override {
         if (extraData.integratorFeeEnabled()) {
-            address integrator = address(bytes20(extraData[:20]));
-            uint256 fee = takingAmount * uint256(uint32(bytes4(extraData[20:24]))) / _TAKING_FEE_BASE;
-            if (fee > 0) {
-                IERC20(order.takerAsset.get()).safeTransferFrom(taker, integrator, fee);
+            uint256 fee = takingAmount * uint256(uint16(bytes2(extraData))) / _FEE_BASE;
+            address feeRecipient = address(bytes20(extraData[2:22]));
+            extraData = extraData[22:];
+
+            address receiver = order.maker.get();
+            if (extraData.hasCustomReceiver()) {
+                receiver = address(bytes20(extraData));
+                extraData = extraData[20:];
+            }
+
+            bool isEth = order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth();
+
+            if (isEth) {
+                if (fee > 0) {
+                    _sendEth(feeRecipient, fee);
+                }
+                unchecked {
+                    _sendEth(receiver, takingAmount - fee);
+                }
+            } else {
+                if (fee > 0) {
+                    IERC20(order.takerAsset.get()).safeTransfer(feeRecipient, fee);
+                }
+                unchecked {
+                    IERC20(order.takerAsset.get()).safeTransfer(receiver, takingAmount - fee);
+                }
             }
-            extraData = extraData[24:];
         }
+
         super._postInteraction(order, extension, orderHash, taker, makingAmount, takingAmount, remainingMakingAmount, extraData);
     }
+
+    /**
+     * @notice Retrieves funds accidently sent directly to the contract address
+     * @param token ERC20 token to retrieve
+     * @param amount amount to retrieve
+     */
+    function rescueFunds(IERC20 token, uint256 amount) external onlyOwner {
+        token.uniTransfer(payable(msg.sender), amount);
+    }
+
+    function _sendEth(address target, uint256 amount) private {
+        (bool success, ) = target.call{value: amount}("");
+        if (!success) {
+            revert EthTransferFailed();
+        }
+    }
 }

contracts/extensions/ResolverFeeExtension.sol

@@ -17,7 +17,7 @@ abstract contract ResolverFeeExtension is BaseExtension, FeeBankCharger {
 
     uint256 private constant _ORDER_FEE_BASE_POINTS = 1e15;
 
-    constructor(IERC20 token) FeeBankCharger(token) {}
+    constructor(IERC20 feeToken) FeeBankCharger(feeToken) {}
 
     /**
      * @dev Calculates the resolver fee.

contracts/mocks/SettlementMock.sol

@@ -6,8 +6,8 @@ import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { Settlement } from "../Settlement.sol";
 
 contract SettlementMock is Settlement {
-    constructor(address limitOrderProtocol, IERC20 token)
-        Settlement(limitOrderProtocol, token)
+    constructor(address limitOrderProtocol, IERC20 token, address weth)
+        Settlement(limitOrderProtocol, token, weth, msg.sender)
     {}
 
     function decreaseAvailableCreditMock(address account, uint256 amount) external {

test/FeeBank.js

@@ -1,4 +1,4 @@
-const { expect, ether, getPermit, deployContract } = require('@1inch/solidity-utils');
+const { expect, ether, getPermit, deployContract, constants } = require('@1inch/solidity-utils');
 const { ethers } = require('hardhat');
 const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
 const { PANIC_CODES } = require('@nomicfoundation/hardhat-chai-matchers/panic');
@@ -11,7 +11,7 @@ describe('FeeBank', function () {
 
         const inch = await deployContract('ERC20PermitMock', ['1INCH', '1INCH', owner, ether('1000')]);
         const { lopv4 } = await deploySwapTokens();
-        const matcher = await deployContract('SettlementMock', [lopv4, inch]);
+        const matcher = await deployContract('SettlementMock', [lopv4, inch, constants.ZERO_ADDRESS]);
 
         const FeeBank = await ethers.getContractFactory('FeeBank');
         const feeBank = FeeBank.attach(await matcher.FEE_BANK());

test/MeasureGas.js

@@ -27,7 +27,7 @@ describe('MeasureGas', function () {
         await weth.deposit({ value: ether('1') });
         await weth.connect(alice).deposit({ value: ether('1') });
 
-        const settlementExtension = await deployContract('Settlement', [lopv4, inch]);
+        const settlementExtension = await deployContract('Settlement', [lopv4, inch, weth, owner]);
         const SettlementV1 = JSON.parse(fs.readFileSync(path.join(__dirname, '../artifacts-v1/SettlementV1.json'), 'utf8'));
         // const settlement = await deployContract(SettlementV1.abi, [lopv3.address, inch.address]);
         const ContractFactory = await ethers.getContractFactory(SettlementV1.abi, SettlementV1.bytecode);
@@ -228,7 +228,7 @@ describe('MeasureGas', function () {
     describe('Extension check', function () {
         it('post interaction', async function () {
             const { contracts: { dai, weth }, accounts: { owner } } = await loadFixture(initContractsAndApproves);
-            const settlementExtension = await deployContract('Settlement', [owner, weth]);
+            const settlementExtension = await deployContract('Settlement', [owner, weth, weth, owner]);
             const currentTime = (await time.latest()) - time.duration.minutes(1);
 
             const postInteractionData = ethers.solidityPacked(

test/PriorityFeeLimiter.js

@@ -17,7 +17,7 @@ describe('PriorityFeeLimiter', function () {
 
     async function prepare() {
         const { contracts: { dai, weth }, accounts: { owner } } = await initContractsForSettlement();
-        const settlementExtension = await deployContract('Settlement', [owner, weth]);
+        const settlementExtension = await deployContract('Settlement', [owner, weth, weth, owner]);
         const currentTime = (await time.latest()) - time.duration.minutes(1);
 
         const postInteractionData = ethers.solidityPacked(