[SC-958] add priority fee limiter

contracts/helpers/PrioirityFeeLimiter.sol

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity 0.8.19;
+
+/// @title A helper contract for executing boolean functions on arbitrary target call results
+contract PriorityFeeLimiter {
+    /// @notice Validates priority fee according to the spec
+    /// https://snapshot.org/#/1inch.eth/proposal/0xa040c60050147a0f67042ae024673e92e813b5d2c0f748abf70ddfa1ed107cbe
+    /// For blocks with baseFee <10.6 gwei – the priorityFee is capped at 70% of the baseFee.
+    /// For blocks with baseFee between 10.6 gwei and 104.1 gwei – the priorityFee is capped at 50% of the baseFee.
+    /// For blocks with baseFee >104.1 gwei – priorityFee is capped at 65% of the block’s baseFee.
+    function isPriorityFeeValid() public view returns(bool) {
+        unchecked {
+            uint256 baseFee = block.basefee;
+            uint256 priorityFee = tx.gasprice - baseFee;
+
+            if (baseFee < 10.6 gwei) {
+                return priorityFee * 100 <= baseFee * 70;
+            } else if (baseFee < 104.1 gwei) {
+                return priorityFee * 2 <= baseFee;
+            } else {
+                return priorityFee * 100 <= baseFee * 65;
+            }
+        }
+    }
+}

deploy/deploy-helpers.js

@@ -63,6 +63,18 @@ module.exports = async ({ getNamedAccounts, deployments }) => {
             address: callsSimulator.address,
         });
     }
+
+    const priorityFeeLimiter = await deploy('PriorityFeeLimiter', {
+        from: deployer,
+    });
+
+    console.log('PriorityFeeLimiter deployed to:', priorityFeeLimiter.address);
+
+    if (await getChainId() !== '31337') {
+        await hre.run('verify:verify', {
+            address: priorityFeeLimiter.address,
+        });
+    }
 };
 
 module.exports.skip = async () => true;

deployments/mainnet/PriorityFeeLimiter.json

@@ -0,0 +1,59 @@
+{
+  "address": "0x5E92d4021e49f9A2967b4EA1d20213B3A1c7c912",
+  "abi": [
+    {
+      "inputs": [],
+      "name": "isPriorityFeeValid",
+      "outputs": [
+        {
+          "internalType": "bool",
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    }
+  ],
+  "transactionHash": "0x1d1ffe931a812a2af71af25b841f63ed6e2a24ee2cdf79eed1e4a2bd64d95c2c",
+  "receipt": {
+    "to": null,
+    "from": "0x11799622F4D98A24514011E8527B969f7488eF47",
+    "contractAddress": "0x5E92d4021e49f9A2967b4EA1d20213B3A1c7c912",
+    "transactionIndex": 117,
+    "gasUsed": "101367",
+    "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    "blockHash": "0x263d3939a79ce71ca11bc2429e003caa0d454342999049de735ae0af77f132c3",
+    "transactionHash": "0x1d1ffe931a812a2af71af25b841f63ed6e2a24ee2cdf79eed1e4a2bd64d95c2c",
+    "logs": [],
+    "blockNumber": 18311797,
+    "cumulativeGasUsed": "11544912",
+    "status": 1,
+    "byzantium": true
+  },
+  "args": [],
+  "numDeployments": 1,
+  "solcInputHash": "6e7c6f92a69228f0d66327ee7f30987a",
+  "metadata": "{\"compiler\":{\"version\":\"0.8.19+commit.7dd6d404\"},\"language\":\"Solidity\",\"output\":{\"abi\":[{\"inputs\":[],\"name\":\"isPriorityFeeValid\",\"outputs\":[{\"internalType\":\"bool\",\"name\":\"\",\"type\":\"bool\"}],\"stateMutability\":\"view\",\"type\":\"function\"}],\"devdoc\":{\"kind\":\"dev\",\"methods\":{},\"title\":\"A helper contract for executing boolean functions on arbitrary target call results\",\"version\":1},\"userdoc\":{\"kind\":\"user\",\"methods\":{\"isPriorityFeeValid()\":{\"notice\":\"Validates priority fee according to the spec https://snapshot.org/#/1inch.eth/proposal/0xa040c60050147a0f67042ae024673e92e813b5d2c0f748abf70ddfa1ed107cbe For blocks with baseFee <10.6 gwei \\u2013 the priorityFee is capped at 70% of the baseFee. For blocks with baseFee between 10.6 gwei and 104.1 gwei \\u2013 the priorityFee is capped at 50% of the baseFee. For blocks with baseFee >104.1 gwei \\u2013 priorityFee is capped at 65% of the block\\u2019s baseFee.\"}},\"version\":1}},\"settings\":{\"compilationTarget\":{\"contracts/helpers/PrioirityFeeLimiter.sol\":\"PriorityFeeLimiter\"},\"evmVersion\":\"paris\",\"libraries\":{},\"metadata\":{\"bytecodeHash\":\"ipfs\",\"useLiteralContent\":true},\"optimizer\":{\"enabled\":true,\"runs\":1000000},\"remappings\":[],\"viaIR\":true},\"sources\":{\"contracts/helpers/PrioirityFeeLimiter.sol\":{\"content\":\"// SPDX-License-Identifier: MIT\\n\\npragma solidity 0.8.19;\\n\\n/// @title A helper contract for executing boolean functions on arbitrary target call results\\ncontract PriorityFeeLimiter {\\n    /// @notice Validates priority fee according to the spec\\n    /// https://snapshot.org/#/1inch.eth/proposal/0xa040c60050147a0f67042ae024673e92e813b5d2c0f748abf70ddfa1ed107cbe\\n    /// For blocks with baseFee <10.6 gwei \\u2013 the priorityFee is capped at 70% of the baseFee.\\n    /// For blocks with baseFee between 10.6 gwei and 104.1 gwei \\u2013 the priorityFee is capped at 50% of the baseFee.\\n    /// For blocks with baseFee >104.1 gwei \\u2013 priorityFee is capped at 65% of the block\\u2019s baseFee.\\n    function isPriorityFeeValid() public view returns(bool) {\\n        unchecked {\\n            uint256 baseFee = block.basefee;\\n            uint256 priorityFee = tx.gasprice - baseFee;\\n\\n            if (baseFee < 10.6 gwei) {\\n                return priorityFee * 100 <= baseFee * 70;\\n            } else if (baseFee < 104.1 gwei) {\\n                return priorityFee * 2 <= baseFee;\\n            } else {\\n                return priorityFee * 100 <= baseFee * 65;\\n            }\\n        }\\n    }\\n}\\n\",\"keccak256\":\"0xec368259e09381c211267f2e735a08a7229efe350c6040bd12553caa40ed3dec\",\"license\":\"MIT\"}},\"version\":1}",
+  "bytecode": "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",
+  "deployedBytecode": "0x6080806040526004361015601257600080fd5b600090813560e01c630202470814602857600080fd5b34606357817ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffc360112606357602090605d6067565b15158152f35b5080fd5b483a03640277cf2a0048106000146085576064604648029102111590565b64183cd7f100481015609b57489060011b111590565b606460414802910211159056fea2646970667358221220fe767365ecbf40522ecd1de1cb05111223125fde69ba80a98aa04be6f0c80f4b64736f6c63430008130033",
+  "devdoc": {
+    "kind": "dev",
+    "methods": {},
+    "title": "A helper contract for executing boolean functions on arbitrary target call results",
+    "version": 1
+  },
+  "userdoc": {
+    "kind": "user",
+    "methods": {
+      "isPriorityFeeValid()": {
+        "notice": "Validates priority fee according to the spec https://snapshot.org/#/1inch.eth/proposal/0xa040c60050147a0f67042ae024673e92e813b5d2c0f748abf70ddfa1ed107cbe For blocks with baseFee <10.6 gwei – the priorityFee is capped at 70% of the baseFee. For blocks with baseFee between 10.6 gwei and 104.1 gwei – the priorityFee is capped at 50% of the baseFee. For blocks with baseFee >104.1 gwei – priorityFee is capped at 65% of the block’s baseFee."
+      }
+    },
+    "version": 1
+  },
+  "storageLayout": {
+    "storage": [],
+    "types": null
+  }
+}

test/PriorityFeeLimiter.js

@@ -0,0 +1,106 @@
+const { expect } = require('@1inch/solidity-utils');
+const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
+const { ether } = require('./helpers/utils');
+const { signOrder, buildOrder, buildTakerTraits } = require('./helpers/orderUtils');
+const { deploySwapTokens } = require('./helpers/fixtures');
+const hre = require('hardhat');
+const { ethers, network } = hre;
+
+describe('PriorityFeeLimiter', function () {
+    let addr, addr1;
+
+    before(async function () {
+        if (hre.__SOLIDITY_COVERAGE_RUNNING) { this.skip(); }
+        [addr, addr1] = await ethers.getSigners();
+    });
+
+    async function deployContractsAndInit () {
+        const { dai, weth, swap, chainId } = await deploySwapTokens();
+
+        await dai.mint(addr.address, ether('2000'));
+        await weth.connect(addr1).deposit({ value: ether('1') });
+
+        await dai.approve(swap.address, ether('2000'));
+        await weth.connect(addr1).approve(swap.address, ether('1'));
+
+        const PriorityFeeLimiter = await ethers.getContractFactory('PriorityFeeLimiter');
+        const priorityFeeLimiter = await PriorityFeeLimiter.deploy();
+        await priorityFeeLimiter.deployed();
+
+        const order = buildOrder(
+            {
+                makerAsset: weth.address,
+                takerAsset: dai.address,
+                makingAmount: ether('1'),
+                takingAmount: ether('2000'),
+                maker: addr1.address,
+            },
+            {
+                predicate: swap.interface.encodeFunctionData('arbitraryStaticCall', [
+                    priorityFeeLimiter.address,
+                    priorityFeeLimiter.interface.encodeFunctionData('isPriorityFeeValid'),
+                ]),
+            },
+        );
+        const signature = await signOrder(order, chainId, swap.address, addr1);
+        const { r, _vs: vs } = ethers.utils.splitSignature(signature);
+        const takerTraits = buildTakerTraits({
+            makingAmount: true,
+            extension: order.extension,
+            minReturn: order.takingAmount,
+        });
+
+        return { dai, weth, swap, order, r, vs, takerTraits };
+    };
+
+    it('8 gwei base, 4 gwei priority should work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0x1dcd65000']);  // 8 gwei
+
+        await swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 4000000000 });
+    });
+
+    it('8 gwei base, 6 gwei priority should not work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0x1dcd65000']);  // 8 gwei
+
+        const fillTx = swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 6000000000 });
+        await expect(fillTx).to.revertedWithCustomError(swap, 'PredicateIsNotTrue');
+    });
+
+    it('50 gwei base, 25 gwei priority should work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0xba43b7400']);  // 50 gwei
+
+        await swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 25000000000 });
+    });
+
+    it('50 gwei base, 26 gwei priority should not work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0xba43b7400']);  // 50 gwei
+
+        const fillTx = swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 26000000000 });
+        await expect(fillTx).to.revertedWithCustomError(swap, 'PredicateIsNotTrue');
+    });
+
+    it('150 gwei base, 90 gwei priority should work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0x22ecb25c00']);  // 150 gwei
+
+        await swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 90000000000 });
+    });
+
+    it('150 gwei base, 100 gwei priority should not work', async function () {
+        const { swap, order, r, vs, takerTraits } = await loadFixture(deployContractsAndInit);
+
+        await network.provider.send('hardhat_setNextBlockBaseFeePerGas', ['0x22ecb25c00']);  // 150 gwei
+
+        const fillTx = swap.fillOrderArgs(order, r, vs, order.makingAmount, takerTraits.traits, takerTraits.args, { maxPriorityFeePerGas: 100000000000 });
+        await expect(fillTx).to.revertedWithCustomError(swap, 'PredicateIsNotTrue');
+    });
+});