Support for rollup mode when using fee token

.env.sample.goerli

@@ -5,3 +5,4 @@ DEVNET_PRIVKEY=""
 
 ## optional - address of already deployed ERC20 token which shall be used as rollup's fee token
 FEE_TOKEN_ADDRESS=""
+FEE_TOKEN_PRICER_ADDRESS=""

.github/workflows/contract-tests.yml

@@ -175,8 +175,8 @@ jobs:
       - name: Compile contracts
         run: yarn build
 
-      - name: Run e2e tests
-        run: yarn test:e2e
+      - name: Run e2e orbit tests
+        run: yarn test:e2e:orbit
   test-e2e-custom-fee-token:
     name: Test e2e custom fee token
     runs-on: ubuntu-latest
@@ -188,9 +188,10 @@ jobs:
       - uses: OffchainLabs/actions/run-nitro-test-node@main
         with:
           l3-node: true
-          args: --l3-fee-token
+          args: --l3-fee-token --l3-fee-token-pricer
           no-token-bridge: true
           no-l3-token-bridge: true
+          nitro-testnode-ref: fee-token-pricer
           nitro-contracts-branch: '${{ github.event.pull_request.head.sha || github.sha }}'
 
       - name: Setup node/yarn
@@ -206,8 +207,11 @@ jobs:
       - name: Compile contracts
         run: yarn build
 
-      - name: Run e2e tests
-        run: yarn test:e2e
+      - name: Run e2e orbit tests
+        run: yarn test:e2e:orbit
+
+      - name: Run e2e orbit custom fee token rollup tests
+        run: yarn test:e2e:orbit-fee-token-rollup
   test-e2e-fee-token-6-decimals:
     name: Test e2e fee token with 6 decimals
     runs-on: ubuntu-latest
@@ -219,9 +223,10 @@ jobs:
       - uses: OffchainLabs/actions/run-nitro-test-node@main
         with:
           l3-node: true
-          args: --l3-fee-token --l3-fee-token-decimals 6
+          args: --l3-fee-token --l3-fee-token-pricer --l3-fee-token-decimals 6
           no-token-bridge: true
           no-l3-token-bridge: true
+          nitro-testnode-ref: fee-token-pricer
           nitro-contracts-branch: '${{ github.event.pull_request.head.sha || github.sha }}'
 
       - name: Setup node/yarn
@@ -238,4 +243,7 @@ jobs:
         run: yarn build
 
       - name: Run e2e tests
-        run: yarn test:e2e
+        run: yarn test:e2e:orbit
+
+      - name: Run e2e orbit custom fee token rollup tests
+        run: yarn test:e2e:orbit-fee-token-rollup

audit-ci.jsonc

@@ -65,6 +65,8 @@
     // Server-Side Request Forgery in axios
     "GHSA-8hc4-vh64-cxmj",
     // Regular Expression Denial of Service (ReDoS) in micromatch
-    "GHSA-952p-6rrq-rcjv"
+    "GHSA-952p-6rrq-rcjv",
+    // cookie accepts cookie name, path, and domain with out of bounds characters
+    "GHSA-pxg6-pf52-xh8x"
   ]
 }

foundry.toml

@@ -24,4 +24,8 @@ auto_detect_remappings = false
 [fmt]
 number_underscore = 'thousands'
 line_length = 100
+
+[fuzz]
+runs = 5000
+
 # See more config options https://github.com/foundry-rs/foundry/tree/master/config

package.json

@@ -30,15 +30,16 @@
     "lint:test": "eslint ./test",
     "solhint": "solhint -f table src/**/*.sol",
     "prettier:solidity": "prettier --write src/**/*.sol",
-    "format": "prettier './**/*.{js,json,ts,yml,sol}' --write && yarn run lint:test --fix",
+    "format": "prettier './test/e2e/**/*.{js,json,ts,yml,sol}' --write && yarn run lint:test --fix",
     "build:0.6": "INTERFACE_TESTER_SOLC_VERSION=0.6.9 yarn run build",
     "build:0.7": "INTERFACE_TESTER_SOLC_VERSION=0.7.0 yarn run build",
     "test": "DISABLE_GAS_REPORTER=true hardhat --network hardhat test test/contract/*.spec.ts",
     "test:4844": "DISABLE_GAS_REPORTER=true hardhat --network hardhat test test/contract/*.spec.4844.ts",
     "test:compatibility": "yarn run build:0.6 && yarn run build:0.7",
     "test:storage": "./test/storage/test.bash",
     "test:signatures": "./test/signatures/test-sigs.bash",
-    "test:e2e": "hardhat test test/e2e/*.ts",
+    "test:e2e:orbit": "hardhat test test/e2e/orbitChain.ts",
+    "test:e2e:orbit-fee-token-rollup": "hardhat test test/e2e/customFeeRollup.ts",
     "test:update": "yarn run test:signatures || yarn run test:storage",
     "metadatahash": "yarn build:all && hardhat run scripts/printMetadataHashes.ts",
     "upload-4bytes": "forge build && find ./out -type f -name \"*.json\" -exec cast upload-signature {} + | grep -v Duplicated:",

scripts/createERC20Rollup.ts

@@ -34,12 +34,18 @@ async function main() {
     throw new Error('ROLLUP_CREATOR_ADDRESS not set')
   }
 
-  console.log('Creating new rollup with', customFeeTokenAddress, 'as fee token')
+  let feeTokenPricer = process.env.FEE_TOKEN_PRICER_ADDRESS
+  if(!feeTokenPricer) {
+    feeTokenPricer = ethers.constants.AddressZero
+  }
+
+  console.log('Creating new rollup with', customFeeTokenAddress, 'as fee token and', feeTokenPricer, 'as fee token pricer')
   await createRollup(
     deployer,
     false,
     rollupCreatorAddress,
-    customFeeTokenAddress
+    customFeeTokenAddress,
+    feeTokenPricer
   )
 }
 

scripts/createEthRollup.ts

@@ -4,14 +4,15 @@ import { createRollup } from './rollupCreation'
 
 async function main() {
   const feeToken = ethers.constants.AddressZero
+  const feeTokenPricer = ethers.constants.AddressZero
   const rollupCreatorAddress = process.env.ROLLUP_CREATOR_ADDRESS
   if (!rollupCreatorAddress) {
     throw new Error('ROLLUP_CREATOR_ADDRESS not set')
   }
 
   const [signer] = await ethers.getSigners()
 
-  await createRollup(signer, false, rollupCreatorAddress, feeToken)
+  await createRollup(signer, false, rollupCreatorAddress, feeToken, feeTokenPricer)
 }
 
 main()

scripts/local-deployment/deployCreatorAndCreateRollup.ts

@@ -41,6 +41,10 @@ async function main() {
   if (!feeToken) {
     feeToken = ethers.constants.AddressZero
   }
+  let feeTokenPricer = process.env.FEE_TOKEN_PRICER_ADDRESS as string
+  if (!feeTokenPricer) {
+    feeTokenPricer = ethers.constants.AddressZero
+  }
 
   /// deploy templates and rollup creator
   console.log('Deploy RollupCreator')
@@ -74,7 +78,8 @@ async function main() {
     deployerWallet,
     true,
     contracts.rollupCreator.address,
-    feeToken
+    feeToken,
+    feeTokenPricer
   )
 
   if (!result) {

scripts/rollupCreation.ts

@@ -3,8 +3,8 @@ import '@nomiclabs/hardhat-ethers'
 import { run } from 'hardhat'
 import { abi as rollupCreatorAbi } from '../build/contracts/src/rollup/RollupCreator.sol/RollupCreator.json'
 import { config, maxDataSize } from './config'
-import { BigNumber, Signer } from 'ethers'
-import { ERC20, ERC20__factory, IERC20__factory } from '../build/types'
+import { BigNumber, Event, Signer } from 'ethers'
+import { ERC20, ERC20__factory, IERC20__factory, RollupCreator } from '../build/types'
 import { sleep } from './testSetup'
 import { promises as fs } from 'fs'
 import { _isRunningOnArbitrum, verifyContract } from './deploymentUtils'
@@ -61,7 +61,8 @@ export async function createRollup(
   signer: Signer,
   isDevDeployment: boolean,
   rollupCreatorAddress: string,
-  feeToken: string
+  feeToken: string,
+  feeTokenPricer: string
 ): Promise<{
   rollupCreationResult: RollupCreationResult
   chainInfo: ChainInfo
@@ -76,7 +77,7 @@ export async function createRollup(
     rollupCreatorAddress,
     rollupCreatorAbi,
     signer
-  )
+  ) as RollupCreator
   const validatorWalletCreator = await rollupCreator.validatorWalletCreator()
 
   try {
@@ -101,7 +102,7 @@ export async function createRollup(
     // Call the createRollup function
     console.log('Calling createRollup to generate a new rollup ...')
     const deployParams = isDevDeployment
-      ? await _getDevRollupConfig(feeToken, validatorWalletCreator)
+      ? await _getDevRollupConfig(feeToken, feeTokenPricer, validatorWalletCreator)
       : {
           config: config.rollupConfig,
           validators: config.validators,
@@ -111,6 +112,7 @@ export async function createRollup(
           maxFeePerGasForRetryables: MAX_FER_PER_GAS,
           batchPosters: config.batchPosters,
           batchPosterManager: config.batchPosterManager,
+          feeTokenPricer: feeTokenPricer
         }
 
     const createRollupTx = await rollupCreator.createRollup(deployParams, {
@@ -119,7 +121,7 @@ export async function createRollup(
     const createRollupReceipt = await createRollupTx.wait()
 
     const rollupCreatedEvent = createRollupReceipt.events?.find(
-      (event: RollupCreatedEvent) =>
+      (event: Event): event is Event =>
         event.event === 'RollupCreated' &&
         event.address.toLowerCase() === rollupCreatorAddress.toLowerCase()
     )
@@ -222,6 +224,7 @@ export async function createRollup(
 
 async function _getDevRollupConfig(
   feeToken: string,
+  feeTokenPricer: string,
   validatorWalletCreator: string
 ) {
   // set up owner address
@@ -321,6 +324,7 @@ async function _getDevRollupConfig(
     maxFeePerGasForRetryables: MAX_FER_PER_GAS,
     batchPosters: batchPosters,
     batchPosterManager: batchPosterManager,
+    feeTokenPricer: feeTokenPricer
   }
 
   function _createValidatorAddress(

src/bridge/ISequencerInbox.sol

@@ -95,6 +95,15 @@ interface ISequencerInbox is IDelayedMessageProvider {
     ///         This enables the batch poster to do key rotation
     function batchPosterManager() external view returns (address);
 
+    /// @notice Pricer contract is used to get the exchange rate between child chain's fee token
+    ///         and parent chain's native token. This is needed when child chain uses custom fee
+    ///         token which is different from parent chain's native token. The exchange rate is
+    ///         used to correctly report converted gas price in the batch spending reports, so
+    ///         that batch poster can get properly reimbursed on the child chain. If chain uses
+    ///         custom fee token, but pricer is not set, then batch poster reports won't be reported
+    ///         and batch poster won't get reimbursed.
+    function feeTokenPricer() external view returns (IFeeTokenPricer);
+
     struct DasKeySetInfo {
         bool isValidKeyset;
         uint64 creationBlock;
@@ -220,10 +229,31 @@ interface ISequencerInbox is IDelayedMessageProvider {
      */
     function setBatchPosterManager(address newBatchPosterManager) external;
 
+    /**
+     * @notice Updates the fee token pricer, the contract which is used to get the exchange rate between child
+     *         chain's fee token and parent chain's native token in rollups that use custom fee token.
+     * @param newFeeTokenPricer The new fee token pricer to be set
+     */
+    function setFeeTokenPricer(IFeeTokenPricer newFeeTokenPricer) external;
+
     /// @notice Allows the rollup owner to sync the rollup address
     function updateRollupAddress() external;
 
     // ---------- initializer ----------
 
-    function initialize(IBridge bridge_, MaxTimeVariation calldata maxTimeVariation_) external;
+    function initialize(
+        IBridge bridge_,
+        MaxTimeVariation calldata maxTimeVariation_,
+        IFeeTokenPricer feeTokenPricer_
+    ) external;
+}
+
+interface IFeeTokenPricer {
+    /**
+     * @notice Get the number of child chain's fee tokens per 1 parent chain's native token. Exchange rate must be
+     *         denominated in 18 decimals. Function is mutable so it allows the pricer to keep internal state.
+     * @dev    For example, parent chain's native token is ETH, fee token is DAI. If price of 1ETH = 2000DAI, then function should return 2000*1e18.
+     *         If fee token is USDC instead and price of 1ETH = 2000USDC, function should still return 2000*1e18, no matter that USDC uses 6 decimals.
+     */
+    function getExchangeRate() external returns (uint256);
 }

src/bridge/SequencerInbox.sol

@@ -29,7 +29,8 @@ import {
     InvalidHeaderFlag,
     NativeTokenMismatch,
     BadMaxTimeVariation,
-    Deprecated
+    Deprecated,
+    CannotSetFeeTokenPricer
 } from "../libraries/Error.sol";
 import "./IBridge.sol";
 import "./IInboxBase.sol";
@@ -117,6 +118,9 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
     /// @inheritdoc ISequencerInbox
     address public batchPosterManager;
 
+    /// @inheritdoc ISequencerInbox
+    IFeeTokenPricer public feeTokenPricer;
+
     // On L1 this should be set to 117964: 90% of Geth's 128KB tx size limit, leaving ~13KB for proving
     uint256 public immutable maxDataSize;
     uint256 internal immutable deployTimeChainId = block.chainid;
@@ -178,7 +182,8 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
 
     function initialize(
         IBridge bridge_,
-        ISequencerInbox.MaxTimeVariation calldata maxTimeVariation_
+        ISequencerInbox.MaxTimeVariation calldata maxTimeVariation_,
+        IFeeTokenPricer feeTokenPricer_
     ) external onlyDelegated {
         if (bridge != IBridge(address(0))) revert AlreadyInit();
         if (bridge_ == IBridge(address(0))) revert HadZeroInit();
@@ -199,6 +204,11 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
         rollup = bridge_.rollup();
 
         _setMaxTimeVariation(maxTimeVariation_);
+
+        if (!isUsingFeeToken && feeTokenPricer_ != IFeeTokenPricer(address(0))) {
+            revert CannotSetFeeTokenPricer();
+        }
+        feeTokenPricer = feeTokenPricer_;
     }
 
     /// @notice Allows the rollup owner to sync the rollup address
@@ -460,7 +470,7 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
         // same as using calldata, we only submit spending report if the caller is the origin of the tx
         // such that one cannot "double-claim" batch posting refund in the same tx
         // solhint-disable-next-line avoid-tx-origin
-        if (msg.sender == tx.origin && !isUsingFeeToken) {
+        if (msg.sender == tx.origin) {
             submitBatchSpendingReport(dataHash, seqMessageIndex, block.basefee, blobGas);
         }
     }
@@ -641,19 +651,37 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
         uint256 gasPrice,
         uint256 extraGas
     ) internal {
+        // When using fee token batch poster needs to be reimbursed on the child chain in the fee token. For that reason
+        // we need to get the exchange rate between the child chain fee token and the parent chain's native token. Pricer
+        // is required to get the exchange rate. If the pricer is not set, then we do not send batch reports and batch poster
+        // never gets reimbursed
+        IFeeTokenPricer _feeTokenPricer = feeTokenPricer;
+        if (isUsingFeeToken && address(_feeTokenPricer) == address(0)) {
+            return;
+        }
+
         // report the account who paid the gas (tx.origin) for the tx as batch poster
         // if msg.sender is used and is a contract, it might not be able to spend the refund on l2
         // solhint-disable-next-line avoid-tx-origin
         address batchPoster = tx.origin;
 
-        // this msg isn't included in the current sequencer batch, but instead added to
-        // the delayed messages queue that is yet to be included
         if (hostChainIsArbitrum) {
             // Include extra gas for the host chain's L1 gas charging
             uint256 l1Fees = ArbGasInfo(address(0x6c)).getCurrentTxL1GasFees();
             extraGas += l1Fees / block.basefee;
         }
         require(extraGas <= type(uint64).max, "EXTRA_GAS_NOT_UINT64");
+
+        if (isUsingFeeToken && address(_feeTokenPricer) != address(0)) {
+            // gasPrice is originally denominated in parent chain's native token and we want to scale it to child
+            // chain's fee token. For that we need the exchange rate which tells us how many child chain's fee tokens
+            // we get for 1 parent chain's native token. Exchange rate itself should be denominated in 18 decimals.
+            uint256 exchangeRate = _feeTokenPricer.getExchangeRate();
+            gasPrice = (gasPrice * exchangeRate) / 1e18;
+        }
+
+        // this msg isn't included in the current sequencer batch, but instead added to
+        // the delayed messages queue that is yet to be included
         bytes memory spendingReportMsg = abi.encodePacked(
             block.timestamp,
             batchPoster,
@@ -698,8 +726,7 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
 
         totalDelayedMessagesRead = afterDelayedMessagesRead;
 
-        if (calldataLengthPosted > 0 && !isUsingFeeToken) {
-            // only report batch poster spendings if chain is using ETH as native currency
+        if (calldataLengthPosted > 0) {
             submitBatchSpendingReport(dataHash, seqMessageIndex, block.basefee, 0);
         }
     }
@@ -792,6 +819,16 @@ contract SequencerInbox is DelegateCallAware, GasRefundEnabled, ISequencerInbox
         emit OwnerFunctionCalled(5);
     }
 
+    /// @inheritdoc ISequencerInbox
+    function setFeeTokenPricer(IFeeTokenPricer feeTokenPricer_) external onlyRollupOwner {
+        if (!isUsingFeeToken) {
+            revert CannotSetFeeTokenPricer();
+        }
+
+        feeTokenPricer = feeTokenPricer_;
+        emit OwnerFunctionCalled(6);
+    }
+
     function isValidKeysetHash(bytes32 ksHash) external view returns (bool) {
         return dasKeySetInfo[ksHash].isValidKeyset;
     }