feat[contracts]: add sequencer fee wallet (#1029)

* wip: first draft of the fee wallet

* add fee wallet to dump

* rename to sequencer vault

* add L1 fee wallet to geth config

* add unit tests

* fix geth linting error

* add a basic integration test

* fix broken integration test

* add test for correct storage slot

* add integration test for fee withdrawal

* fix typo in integration tests

* fix a bug bin integration tests

* Update OVM_SequencerFeeVault.sol

* fix bug in contract tests

* chore: add changeset

* fix bug in contract tests

.changeset/shy-brooms-divide.md

@@ -0,0 +1,7 @@
+---
+'@eth-optimism/integration-tests': patch
+'@eth-optimism/l2geth': patch
+'@eth-optimism/contracts': patch
+---
+
+Adds new SequencerFeeVault contract to store generated fees

integration-tests/test/fee-payment.spec.ts

@@ -1,18 +1,33 @@
 import chai, { expect } from 'chai'
 import chaiAsPromised from 'chai-as-promised'
 chai.use(chaiAsPromised)
-import { BigNumber, utils } from 'ethers'
-import { OptimismEnv } from './shared/env'
+
+/* Imports: External */
+import { BigNumber, Contract, utils } from 'ethers'
 import { TxGasLimit, TxGasPrice } from '@eth-optimism/core-utils'
+import { predeploys, getContractInterface } from '@eth-optimism/contracts'
+
+/* Imports: Internal */
+import { OptimismEnv } from './shared/env'
+import { Direction } from './shared/watcher-utils'
 
 describe('Fee Payment Integration Tests', async () => {
-  let env: OptimismEnv
   const other = '0x1234123412341234123412341234123412341234'
 
+  let env: OptimismEnv
   before(async () => {
     env = await OptimismEnv.new()
   })
 
+  let ovmSequencerFeeVault: Contract
+  before(async () => {
+    ovmSequencerFeeVault = new Contract(
+      predeploys.OVM_SequencerFeeVault,
+      getContractInterface('OVM_SequencerFeeVault'),
+      env.l2Wallet
+    )
+  })
+
   it(`Should return a gasPrice of ${TxGasPrice.toString()} wei`, async () => {
     const gasPrice = await env.l2Wallet.getGasPrice()
     expect(gasPrice).to.deep.eq(TxGasPrice)
@@ -36,17 +51,63 @@ describe('Fee Payment Integration Tests', async () => {
   it('Paying a nonzero but acceptable gasPrice fee', async () => {
     const amount = utils.parseEther('0.5')
     const balanceBefore = await env.l2Wallet.getBalance()
+    const feeVaultBalanceBefore = await env.l2Wallet.provider.getBalance(
+      ovmSequencerFeeVault.address
+    )
     expect(balanceBefore.gt(amount))
 
     const tx = await env.ovmEth.transfer(other, amount)
     const receipt = await tx.wait()
     expect(receipt.status).to.eq(1)
 
     const balanceAfter = await env.l2Wallet.getBalance()
+    const feeVaultBalanceAfter = await env.l2Wallet.provider.getBalance(
+      ovmSequencerFeeVault.address
+    )
+    const expectedFeePaid = tx.gasPrice.mul(tx.gasLimit)
+
     // The fee paid MUST be the receipt.gasUsed, and not the tx.gasLimit
     // https://github.com/ethereum-optimism/optimism/blob/0de7a2f9c96a7c4860658822231b2d6da0fefb1d/packages/contracts/contracts/optimistic-ethereum/OVM/accounts/OVM_ECDSAContractAccount.sol#L103
-    expect(balanceBefore.sub(balanceAfter)).to.be.deep.eq(
-      tx.gasPrice.mul(tx.gasLimit).add(amount)
+    expect(balanceBefore.sub(balanceAfter)).to.deep.equal(
+      expectedFeePaid.add(amount)
+    )
+
+    // Make sure the fee was transferred to the vault.
+    expect(feeVaultBalanceAfter.sub(feeVaultBalanceBefore)).to.deep.equal(
+      expectedFeePaid
+    )
+  })
+
+  it('should not be able to withdraw fees before the minimum is met', async () => {
+    await expect(ovmSequencerFeeVault.withdraw()).to.be.rejected
+  })
+
+  it('should be able to withdraw fees back to L1 once the minimum is met', async () => {
+    const l1FeeWallet = await ovmSequencerFeeVault.l1FeeWallet()
+    const balanceBefore = await env.l1Wallet.provider.getBalance(l1FeeWallet)
+
+    // Transfer the minimum required to withdraw.
+    await env.ovmEth.transfer(
+      ovmSequencerFeeVault.address,
+      await ovmSequencerFeeVault.MIN_WITHDRAWAL_AMOUNT()
+    )
+
+    const vaultBalance = await env.ovmEth.balanceOf(
+      ovmSequencerFeeVault.address
+    )
+
+    // Submit the withdrawal.
+    const withdrawTx = await ovmSequencerFeeVault.withdraw({
+      gasPrice: 0, // Need a gasprice of 0 or the balances will include the fee paid during this tx.
+    })
+
+    // Wait for the withdrawal to be relayed to L1.
+    await env.waitForXDomainTransaction(withdrawTx, Direction.L2ToL1)
+
+    // Balance difference should be equal to old L2 balance.
+    const balanceAfter = await env.l1Wallet.provider.getBalance(l1FeeWallet)
+    expect(balanceAfter.sub(balanceBefore)).to.deep.equal(
+      BigNumber.from(vaultBalance)
     )
   })
 })

integration-tests/test/shared/env.ts

@@ -58,7 +58,7 @@ export class OptimismEnv {
     // fund the user if needed
     const balance = await l2Wallet.getBalance()
     if (balance.isZero()) {
-      await fundUser(watcher, gateway, utils.parseEther('10'))
+      await fundUser(watcher, gateway, utils.parseEther('20'))
     }
 
     const ovmEth = getOvmEth(l2Wallet)

l2geth/README.md

@@ -50,6 +50,7 @@ $ USING_OVM=true ./build/bin/geth \
     --eth1.chainid $LAYER1_CHAIN_ID \
     --eth1.l1gatewayaddress $ETH1_L1_GATEWAY_ADDRESS \
     --eth1.l1crossdomainmessengeraddress $ETH1_L1_CROSS_DOMAIN_MESSENGER_ADDRESS \
+    --eth1.l1feewalletaddress $ETH1_L1_FEE_WALLET_ADDRESS \
     --eth1.addressresolveraddress $ETH1_ADDRESS_RESOLVER_ADDRESS \
     --eth1.ctcdeploymentheight $CTC_DEPLOY_HEIGHT \
     --eth1.syncservice \

l2geth/cmd/geth/main.go

@@ -153,6 +153,7 @@ var (
 		utils.Eth1SyncServiceEnable,
 		utils.Eth1CanonicalTransactionChainDeployHeightFlag,
 		utils.Eth1L1CrossDomainMessengerAddressFlag,
+		utils.Eth1L1FeeWalletAddressFlag,
 		utils.Eth1ETHGatewayAddressFlag,
 		utils.Eth1ChainIdFlag,
 		utils.RollupClientHttpFlag,

l2geth/cmd/geth/usage.go

@@ -68,6 +68,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.Eth1SyncServiceEnable,
 			utils.Eth1CanonicalTransactionChainDeployHeightFlag,
 			utils.Eth1L1CrossDomainMessengerAddressFlag,
+			utils.Eth1L1FeeWalletAddressFlag,
 			utils.Eth1ETHGatewayAddressFlag,
 			utils.Eth1ChainIdFlag,
 			utils.RollupClientHttpFlag,

l2geth/cmd/utils/flags.go

@@ -822,6 +822,12 @@ var (
 		Value:  "0x0000000000000000000000000000000000000000",
 		EnvVar: "ETH1_L1_CROSS_DOMAIN_MESSENGER_ADDRESS",
 	}
+	Eth1L1FeeWalletAddressFlag = cli.StringFlag{
+		Name:   "eth1.l1feewalletaddress",
+		Usage:  "Address of the L1 wallet that will collect fees",
+		Value:  "0x0000000000000000000000000000000000000000",
+		EnvVar: "ETH1_L1_FEE_WALLET_ADDRESS",
+	}
 	Eth1ETHGatewayAddressFlag = cli.StringFlag{
 		Name:   "eth1.l1ethgatewayaddress",
 		Usage:  "Deployment address of the Ethereum gateway",
@@ -1148,6 +1154,10 @@ func setEth1(ctx *cli.Context, cfg *rollup.Config) {
 		addr := ctx.GlobalString(Eth1L1CrossDomainMessengerAddressFlag.Name)
 		cfg.L1CrossDomainMessengerAddress = common.HexToAddress(addr)
 	}
+	if ctx.GlobalIsSet(Eth1L1FeeWalletAddressFlag.Name) {
+		addr := ctx.GlobalString(Eth1L1FeeWalletAddressFlag.Name)
+		cfg.L1FeeWalletAddress = common.HexToAddress(addr)
+	}
 	if ctx.GlobalIsSet(Eth1ETHGatewayAddressFlag.Name) {
 		addr := ctx.GlobalString(Eth1ETHGatewayAddressFlag.Name)
 		cfg.L1ETHGatewayAddress = common.HexToAddress(addr)
@@ -1777,10 +1787,11 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 			gasLimit = params.GenesisGasLimit
 		}
 		xdomainAddress := cfg.Rollup.L1CrossDomainMessengerAddress
+		l1FeeWalletAddress := cfg.Rollup.L1FeeWalletAddress
 		addrManagerOwnerAddress := cfg.Rollup.AddressManagerOwnerAddress
 		l1ETHGatewayAddress := cfg.Rollup.L1ETHGatewayAddress
 		stateDumpPath := cfg.Rollup.StateDumpPath
-		cfg.Genesis = core.DeveloperGenesisBlock(uint64(ctx.GlobalInt(DeveloperPeriodFlag.Name)), developer.Address, xdomainAddress, l1ETHGatewayAddress, addrManagerOwnerAddress, stateDumpPath, chainID, gasLimit)
+		cfg.Genesis = core.DeveloperGenesisBlock(uint64(ctx.GlobalInt(DeveloperPeriodFlag.Name)), developer.Address, xdomainAddress, l1ETHGatewayAddress, addrManagerOwnerAddress, l1FeeWalletAddress, stateDumpPath, chainID, gasLimit)
 		if !ctx.GlobalIsSet(MinerGasPriceFlag.Name) && !ctx.GlobalIsSet(MinerLegacyGasPriceFlag.Name) {
 			cfg.Miner.GasPrice = big.NewInt(1)
 		}

l2geth/console/console_test.go

@@ -98,7 +98,7 @@ func newTester(t *testing.T, confOverride func(*eth.Config)) *tester {
 		t.Fatalf("failed to create node: %v", err)
 	}
 	ethConf := &eth.Config{
-		Genesis: core.DeveloperGenesisBlock(15, common.Address{}, common.Address{}, common.Address{}, common.Address{}, "", nil, 12000000),
+		Genesis: core.DeveloperGenesisBlock(15, common.Address{}, common.Address{}, common.Address{}, common.Address{}, common.Address{}, "", nil, 12000000),
 		Miner: miner.Config{
 			Etherbase: common.HexToAddress(testAddress),
 		},

l2geth/core/genesis.go

@@ -69,6 +69,7 @@ type Genesis struct {
 
 	// OVM Specific, used to initialize the l1XDomainMessengerAddress
 	// in the genesis state
+	L1FeeWalletAddress            common.Address `json:"-"`
 	L1CrossDomainMessengerAddress common.Address `json:"-"`
 	AddressManagerOwnerAddress    common.Address `json:"-"`
 	L1ETHGatewayAddress           common.Address `json:"-"`
@@ -266,7 +267,7 @@ func (g *Genesis) configOrDefault(ghash common.Hash) *params.ChainConfig {
 }
 
 // ApplyOvmStateToState applies the initial OVM state to a state object.
-func ApplyOvmStateToState(statedb *state.StateDB, stateDump *dump.OvmDump, l1XDomainMessengerAddress common.Address, l1ETHGatewayAddress common.Address, addrManagerOwnerAddress common.Address, chainID *big.Int, gasLimit uint64) {
+func ApplyOvmStateToState(statedb *state.StateDB, stateDump *dump.OvmDump, l1XDomainMessengerAddress common.Address, l1ETHGatewayAddress common.Address, addrManagerOwnerAddress common.Address, l1FeeWalletAddress common.Address, chainID *big.Int, gasLimit uint64) {
 	if len(stateDump.Accounts) == 0 {
 		return
 	}
@@ -330,6 +331,13 @@ func ApplyOvmStateToState(statedb *state.StateDB, stateDump *dump.OvmDump, l1XDo
 		maxTxGasLimitValue := common.BytesToHash(new(big.Int).SetUint64(gasLimit).Bytes())
 		statedb.SetState(ExecutionManager.Address, maxTxGasLimitSlot, maxTxGasLimitValue)
 	}
+	OVM_SequencerFeeVault, ok := stateDump.Accounts["OVM_SequencerFeeVault"]
+	if ok {
+		log.Info("Setting l1FeeWallet in OVM_SequencerFeeVault", "wallet", l1FeeWalletAddress.Hex())
+		l1FeeWalletSlot := common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000000")
+		l1FeeWalletValue := common.BytesToHash(l1FeeWalletAddress.Bytes())
+		statedb.SetState(OVM_SequencerFeeVault.Address, l1FeeWalletSlot, l1FeeWalletValue)
+	}
 }
 
 // ToBlock creates the genesis block and writes state of a genesis specification
@@ -342,7 +350,7 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 
 	if vm.UsingOVM {
 		// OVM_ENABLED
-		ApplyOvmStateToState(statedb, g.Config.StateDump, g.L1CrossDomainMessengerAddress, g.L1ETHGatewayAddress, g.AddressManagerOwnerAddress, g.ChainID, g.GasLimit)
+		ApplyOvmStateToState(statedb, g.Config.StateDump, g.L1CrossDomainMessengerAddress, g.L1ETHGatewayAddress, g.AddressManagerOwnerAddress, g.L1FeeWalletAddress, g.ChainID, g.GasLimit)
 	}
 
 	for addr, account := range g.Alloc {
@@ -469,7 +477,7 @@ func DefaultGoerliGenesisBlock() *Genesis {
 }
 
 // DeveloperGenesisBlock returns the 'geth --dev' genesis block.
-func DeveloperGenesisBlock(period uint64, faucet, l1XDomainMessengerAddress common.Address, l1ETHGatewayAddress common.Address, addrManagerOwnerAddress common.Address, stateDumpPath string, chainID *big.Int, gasLimit uint64) *Genesis {
+func DeveloperGenesisBlock(period uint64, faucet, l1XDomainMessengerAddress common.Address, l1ETHGatewayAddress common.Address, addrManagerOwnerAddress common.Address, l1FeeWalletAddress common.Address, stateDumpPath string, chainID *big.Int, gasLimit uint64) *Genesis {
 	// Override the default period to the user requested one
 	config := *params.AllCliqueProtocolChanges
 	config.Clique.Period = period
@@ -525,6 +533,7 @@ func DeveloperGenesisBlock(period uint64, faucet, l1XDomainMessengerAddress comm
 			common.BytesToAddress([]byte{8}): {Balance: big.NewInt(1)}, // ECPairing
 		},
 		L1CrossDomainMessengerAddress: l1XDomainMessengerAddress,
+		L1FeeWalletAddress:            l1FeeWalletAddress,
 		AddressManagerOwnerAddress:    addrManagerOwnerAddress,
 		L1ETHGatewayAddress:           l1ETHGatewayAddress,
 		ChainID:                       config.ChainID,

l2geth/rollup/config.go

@@ -23,6 +23,7 @@ type Config struct {
 	// HTTP endpoint of the data transport layer
 	RollupClientHttp              string
 	L1CrossDomainMessengerAddress common.Address
+	L1FeeWalletAddress            common.Address
 	AddressManagerOwnerAddress    common.Address
 	L1ETHGatewayAddress           common.Address
 	GasPriceOracleAddress         common.Address

l2geth/scripts/start.sh

@@ -33,6 +33,7 @@ CLI Arguments:
   --eth1.chainid                         - eth1 chain id
   --eth1.ctcdeploymentheight             - eth1 ctc deploy height
   --eth1.l1crossdomainmessengeraddress   - eth1 l1 xdomain messenger address
+  --eth1.l1feewalletaddress              - eth l1 fee wallet address
   --rollup.statedumppath                 - http path to the initial state dump
   --rollup.clienthttp                    - rollup client http
   --rollup.pollinterval                  - polling interval for the rollup client
@@ -127,6 +128,15 @@ while (( "$#" )); do
                 exit 1
             fi
             ;;
+        --eth1.l1feewalletaddress)
+            if [ -n "$2" ] && [ ${2:0:1} != "-" ]; then
+                ETH1_L1_FEE_WALLET_ADDRESS="$2"
+                shift 2
+            else
+                echo "Error: Argument for $1 is missing" >&2
+                exit 1
+            fi
+            ;;
         --eth1.l1ethgatewayaddress)
             if [ -n "$2" ] && [ ${2:0:1} != "-" ]; then
                 ETH1_L1_ETH_GATEWAY_ADDRESS="$2"
@@ -230,6 +240,7 @@ if [[ ! -z "$ROLLUP_SYNC_SERVICE_ENABLE" ]]; then
 fi
 cmd="$cmd --datadir $DATADIR"
 cmd="$cmd --eth1.l1crossdomainmessengeraddress $ETH1_L1_CROSS_DOMAIN_MESSENGER_ADDRESS"
+cmd="$cmd --eth1.l1feewalletaddress $ETH1_L1_FEE_WALLET_ADDRESS"
 cmd="$cmd --rollup.addressmanagerowneraddress $ADDRESS_MANAGER_OWNER_ADDRESS"
 cmd="$cmd --rollup.statedumppath $ROLLUP_STATE_DUMP_PATH"
 cmd="$cmd --eth1.ctcdeploymentheight $ETH1_CTC_DEPLOYMENT_HEIGHT"

packages/contracts/contracts/optimistic-ethereum/OVM/accounts/OVM_ECDSAContractAccount.sol

@@ -8,6 +8,7 @@ import { iOVM_ECDSAContractAccount } from "../../iOVM/accounts/iOVM_ECDSAContrac
 /* Library Imports */
 import { Lib_EIP155Tx } from "../../libraries/codec/Lib_EIP155Tx.sol";
 import { Lib_ExecutionManagerWrapper } from "../../libraries/wrappers/Lib_ExecutionManagerWrapper.sol";
+import { Lib_PredeployAddresses } from "../../libraries/constants/Lib_PredeployAddresses.sol";
 
 /* Contract Imports */
 import { OVM_ETH } from "../predeploys/OVM_ETH.sol";
@@ -40,7 +41,6 @@ contract OVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
     // TODO: should be the amount sufficient to cover the gas costs of all of the transactions up
     // to and including the CALL/CREATE which forms the entrypoint of the transaction.
     uint256 constant EXECUTION_VALIDATION_GAS_OVERHEAD = 25000;
-    OVM_ETH constant ovmETH = OVM_ETH(0x4200000000000000000000000000000000000006);
 
 
     /********************
@@ -92,8 +92,8 @@ contract OVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
 
         // Transfer fee to relayer.
         require(
-            ovmETH.transfer(
-                msg.sender,
+            OVM_ETH(Lib_PredeployAddresses.OVM_ETH).transfer(
+                Lib_PredeployAddresses.SEQUENCER_FEE_WALLET,
                 SafeMath.mul(transaction.gasLimit, transaction.gasPrice)
             ),
             "Fee was not transferred to relayer."
@@ -131,7 +131,7 @@ contract OVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
                 );
 
                 require(
-                    ovmETH.transfer(
+                    OVM_ETH(Lib_PredeployAddresses.OVM_ETH).transfer(
                         transaction.to,
                         transaction.value
                     ),

packages/contracts/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerFeeVault.sol

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >0.5.0 <0.8.0;
+
+/* Library Imports */
+import { Lib_PredeployAddresses } from "../../libraries/constants/Lib_PredeployAddresses.sol";
+
+/* Contract Imports */
+import { OVM_ETH } from "../predeploys/OVM_ETH.sol";
+
+/**
+ * @title OVM_SequencerFeeVault
+ * @dev Simple holding contract for fees paid to the Sequencer. Likely to be replaced in the future
+ * but "good enough for now".
+ *
+ * Compiler used: optimistic-solc
+ * Runtime target: OVM
+ */
+contract OVM_SequencerFeeVault {
+
+    /*************
+     * Constants *
+     *************/
+
+    // Minimum ETH balance that can be withdrawn in a single withdrawal.
+    uint256 public constant MIN_WITHDRAWAL_AMOUNT = 15 ether;
+
+
+    /*************
+     * Variables *
+     *************/
+
+    // Address on L1 that will hold the fees once withdrawn. Dynamically initialized within l2geth.
+    address public l1FeeWallet;
+
+
+    /***************
+     * Constructor *
+     ***************/
+
+    /**
+     * @param _l1FeeWallet Initial address for the L1 wallet that will hold fees once withdrawn.
+     * Currently HAS NO EFFECT in production because l2geth will mutate this storage slot during
+     * the genesis block. This is ONLY for testing purposes.
+     */
+    constructor(
+        address _l1FeeWallet
+    ) {
+        l1FeeWallet = _l1FeeWallet;
+    }
+
+
+    /********************
+     * Public Functions *
+     ********************/
+
+    function withdraw()
+        public
+    {
+        uint256 balance = OVM_ETH(Lib_PredeployAddresses.OVM_ETH).balanceOf(address(this));
+
+        require(
+            balance >= MIN_WITHDRAWAL_AMOUNT,
+            "OVM_SequencerFeeVault: withdrawal amount must be greater than minimum withdrawal amount"
+        );
+
+        OVM_ETH(Lib_PredeployAddresses.OVM_ETH).withdrawTo(
+            l1FeeWallet,
+            balance,
+            0,
+            bytes("")
+        );
+    }
+}