exclude CL withdrawals from profit calculation (ethereum#144)

Author: dvush

builder/config.go

@@ -22,6 +22,7 @@ type Config struct {
 	SecondaryRemoteRelayEndpoints    []string      `toml:",omitempty"`
 	ValidationBlocklist              string        `toml:",omitempty"`
 	ValidationUseCoinbaseDiff        bool          `toml:",omitempty"`
+	ValidationExcludeWithdrawals     bool          `toml:",omitempty"`
 	BuilderRateLimitDuration         string        `toml:",omitempty"`
 	BuilderRateLimitMaxBurst         int           `toml:",omitempty"`
 	BuilderRateLimitResubmitInterval string        `toml:",omitempty"`
@@ -52,6 +53,7 @@ var DefaultConfig = Config{
 	SecondaryRemoteRelayEndpoints: nil,
 	ValidationBlocklist:           "",
 	ValidationUseCoinbaseDiff:     false,
+	ValidationExcludeWithdrawals:  false,
 	BuilderRateLimitDuration:      RateLimitIntervalDefault.String(),
 	BuilderRateLimitMaxBurst:      RateLimitBurstDefault,
 	DiscardRevertibleTxOnErr:      false,

builder/service.go

@@ -214,7 +214,7 @@ func Register(stack *node.Node, backend *eth.Ethereum, cfg *Config) error {
 				return fmt.Errorf("failed to load validation blocklist %w", err)
 			}
 		}
-		validator = blockvalidation.NewBlockValidationAPI(backend, accessVerifier, cfg.ValidationUseCoinbaseDiff)
+		validator = blockvalidation.NewBlockValidationAPI(backend, accessVerifier, cfg.ValidationUseCoinbaseDiff, cfg.ValidationExcludeWithdrawals)
 	}
 
 	// Set up builder rate limiter based on environment variables or CLI flags.

cmd/geth/config.go

@@ -180,6 +180,9 @@ func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 	if ctx.IsSet(utils.BuilderBlockValidationUseBalanceDiff.Name) {
 		bvConfig.UseBalanceDiffProfit = ctx.Bool(utils.BuilderBlockValidationUseBalanceDiff.Name)
 	}
+	if ctx.IsSet(utils.BuilderBlockValidationExcludeWithdrawals.Name) {
+		bvConfig.ExcludeWithdrawals = ctx.Bool(utils.BuilderBlockValidationExcludeWithdrawals.Name)
+	}
 
 	if err := blockvalidationapi.Register(stack, eth, bvConfig); err != nil {
 		utils.Fatalf("Failed to register the Block Validation API: %v", err)

cmd/geth/main.go

@@ -163,6 +163,7 @@ var (
 		utils.BuilderEnableValidatorChecks,
 		utils.BuilderBlockValidationBlacklistSourceFilePath,
 		utils.BuilderBlockValidationUseBalanceDiff,
+		utils.BuilderBlockValidationExcludeWithdrawals,
 		utils.BuilderEnableLocalRelay,
 		utils.BuilderSecondsInSlot,
 		utils.BuilderSlotsInEpoch,

cmd/utils/flags.go

@@ -741,6 +741,12 @@ var (
 		Value:    false,
 		Category: flags.BuilderCategory,
 	}
+	BuilderBlockValidationExcludeWithdrawals = &cli.BoolFlag{
+		Name:     "builder.validation_exclude_withdrawals",
+		Usage:    "Block validation API will exclude CL withdrawals to the fee recipient from the balance delta.",
+		Value:    false,
+		Category: flags.BuilderCategory,
+	}
 	BuilderEnableLocalRelay = &cli.BoolFlag{
 		Name:     "builder.local_relay",
 		Usage:    "Enable the local relay",
@@ -1724,6 +1730,7 @@ func SetBuilderConfig(ctx *cli.Context, cfg *builder.Config) {
 		cfg.ValidationBlocklist = ctx.String(BuilderBlockValidationBlacklistSourceFilePath.Name)
 	}
 	cfg.ValidationUseCoinbaseDiff = ctx.Bool(BuilderBlockValidationUseBalanceDiff.Name)
+	cfg.ValidationExcludeWithdrawals = ctx.Bool(BuilderBlockValidationExcludeWithdrawals.Name)
 	cfg.BuilderRateLimitDuration = ctx.String(BuilderRateLimitDuration.Name)
 	cfg.BuilderRateLimitMaxBurst = ctx.Int(BuilderRateLimitMaxBurst.Name)
 	cfg.BuilderSubmissionOffset = ctx.Duration(BuilderSubmissionOffset.Name)

core/blockchain.go

@@ -2498,7 +2498,8 @@ func (bc *BlockChain) SetBlockValidatorAndProcessorForTesting(v Validator, p Pro
 // It returns nil if the payload is valid, otherwise it returns an error.
 //   - `useBalanceDiffProfit` if set to false, proposer payment is assumed to be in the last transaction of the block
 //     otherwise we use proposer balance changes after the block to calculate proposer payment (see details in the code)
-func (bc *BlockChain) ValidatePayload(block *types.Block, feeRecipient common.Address, expectedProfit *big.Int, registeredGasLimit uint64, vmConfig vm.Config, useBalanceDiffProfit bool) error {
+//   - `excludeWithdrawals` if set to true, withdrawals to the fee recipient are excluded from the balance change
+func (bc *BlockChain) ValidatePayload(block *types.Block, feeRecipient common.Address, expectedProfit *big.Int, registeredGasLimit uint64, vmConfig vm.Config, useBalanceDiffProfit, excludeWithdrawals bool) error {
 	header := block.Header()
 	if err := bc.engine.VerifyHeader(bc, header, true); err != nil {
 		return err
@@ -2540,6 +2541,14 @@ func (bc *BlockChain) ValidatePayload(block *types.Block, feeRecipient common.Ad
 
 	feeRecipientBalanceDelta := new(big.Int).Set(statedb.GetBalance(feeRecipient))
 	feeRecipientBalanceDelta.Sub(feeRecipientBalanceDelta, feeRecipientBalanceBefore)
+	if excludeWithdrawals {
+		for _, w := range block.Withdrawals() {
+			if w.Address == feeRecipient {
+				amount := new(big.Int).Mul(new(big.Int).SetUint64(w.Amount), big.NewInt(params.GWei))
+				feeRecipientBalanceDelta.Sub(feeRecipientBalanceDelta, amount)
+			}
+		}
+	}
 
 	if bc.Config().IsShanghai(header.Time) {
 		if header.WithdrawalsHash == nil {

eth/block-validation/api.go

@@ -90,6 +90,8 @@ type BlockValidationConfig struct {
 	BlacklistSourceFilePath string
 	// If set to true, proposer payment is calculated as a balance difference of the fee recipient.
 	UseBalanceDiffProfit bool
+	// If set to true, withdrawals to the fee recipient are excluded from the balance difference.
+	ExcludeWithdrawals bool
 }
 
 // Register adds catalyst APIs to the full node.
@@ -106,7 +108,7 @@ func Register(stack *node.Node, backend *eth.Ethereum, cfg BlockValidationConfig
 	stack.RegisterAPIs([]rpc.API{
 		{
 			Namespace: "flashbots",
-			Service:   NewBlockValidationAPI(backend, accessVerifier, cfg.UseBalanceDiffProfit),
+			Service:   NewBlockValidationAPI(backend, accessVerifier, cfg.UseBalanceDiffProfit, cfg.ExcludeWithdrawals),
 		},
 	})
 	return nil
@@ -117,15 +119,18 @@ type BlockValidationAPI struct {
 	accessVerifier *AccessVerifier
 	// If set to true, proposer payment is calculated as a balance difference of the fee recipient.
 	useBalanceDiffProfit bool
+	// If set to true, withdrawals to the fee recipient are excluded from the balance delta.
+	excludeWithdrawals bool
 }
 
 // NewConsensusAPI creates a new consensus api for the given backend.
 // The underlying blockchain needs to have a valid terminal total difficulty set.
-func NewBlockValidationAPI(eth *eth.Ethereum, accessVerifier *AccessVerifier, useBalanceDiffProfit bool) *BlockValidationAPI {
+func NewBlockValidationAPI(eth *eth.Ethereum, accessVerifier *AccessVerifier, useBalanceDiffProfit, excludeWithdrawals bool) *BlockValidationAPI {
 	return &BlockValidationAPI{
 		eth:                  eth,
 		accessVerifier:       accessVerifier,
 		useBalanceDiffProfit: useBalanceDiffProfit,
+		excludeWithdrawals:   excludeWithdrawals,
 	}
 }
 
@@ -185,7 +190,7 @@ func (api *BlockValidationAPI) ValidateBuilderSubmissionV1(params *BuilderBlockV
 		vmconfig = vm.Config{Tracer: tracer, Debug: true}
 	}
 
-	err = api.eth.BlockChain().ValidatePayload(block, feeRecipient, expectedProfit, params.RegisteredGasLimit, vmconfig, api.useBalanceDiffProfit)
+	err = api.eth.BlockChain().ValidatePayload(block, feeRecipient, expectedProfit, params.RegisteredGasLimit, vmconfig, api.useBalanceDiffProfit, api.excludeWithdrawals)
 	if err != nil {
 		log.Error("invalid payload", "hash", payload.BlockHash.String(), "number", payload.BlockNumber, "parentHash", payload.ParentHash.String(), "err", err)
 		return err
@@ -277,7 +282,7 @@ func (api *BlockValidationAPI) ValidateBuilderSubmissionV2(params *BuilderBlockV
 		vmconfig = vm.Config{Tracer: tracer, Debug: true}
 	}
 
-	err = api.eth.BlockChain().ValidatePayload(block, feeRecipient, expectedProfit, params.RegisteredGasLimit, vmconfig, api.useBalanceDiffProfit)
+	err = api.eth.BlockChain().ValidatePayload(block, feeRecipient, expectedProfit, params.RegisteredGasLimit, vmconfig, api.useBalanceDiffProfit, api.excludeWithdrawals)
 	if err != nil {
 		log.Error("invalid payload", "hash", payload.BlockHash.String(), "number", payload.BlockNumber, "parentHash", payload.ParentHash.String(), "err", err)
 		return err

eth/block-validation/api_test.go

@@ -69,7 +69,7 @@ func TestValidateBuilderSubmissionV1(t *testing.T) {
 	ethservice.Merger().ReachTTD()
 	defer n.Close()
 
-	api := NewBlockValidationAPI(ethservice, nil, true)
+	api := NewBlockValidationAPI(ethservice, nil, true, true)
 	parent := preMergeBlocks[len(preMergeBlocks)-1]
 
 	api.eth.APIBackend.Miner().SetEtherbase(testValidatorAddr)
@@ -179,7 +179,7 @@ func TestValidateBuilderSubmissionV2(t *testing.T) {
 	ethservice.Merger().ReachTTD()
 	defer n.Close()
 
-	api := NewBlockValidationAPI(ethservice, nil, true)
+	api := NewBlockValidationAPI(ethservice, nil, true, true)
 	parent := preMergeBlocks[len(preMergeBlocks)-1]
 
 	api.eth.APIBackend.Miner().SetEtherbase(testBuilderAddr)
@@ -623,7 +623,7 @@ func TestValidateBuilderSubmissionV2_CoinbasePaymentDefault(t *testing.T) {
 	ethservice.Merger().ReachTTD()
 	defer n.Close()
 
-	api := NewBlockValidationAPI(ethservice, nil, true)
+	api := NewBlockValidationAPI(ethservice, nil, true, true)
 
 	baseFee := misc.CalcBaseFee(ethservice.BlockChain().Config(), lastBlock.Header())
 	txs := make(types.Transactions, 0)
@@ -735,8 +735,8 @@ func TestValidateBuilderSubmissionV2_Blocklist(t *testing.T) {
 		},
 	}
 
-	apiWithBlock := NewBlockValidationAPI(ethservice, accessVerifier, true)
-	apiNoBlock := NewBlockValidationAPI(ethservice, nil, true)
+	apiWithBlock := NewBlockValidationAPI(ethservice, accessVerifier, true, true)
+	apiNoBlock := NewBlockValidationAPI(ethservice, nil, true, true)
 
 	baseFee := misc.CalcBaseFee(ethservice.BlockChain().Config(), lastBlock.Header())
 	blockedTxs := make(types.Transactions, 0)
@@ -782,3 +782,101 @@ func TestValidateBuilderSubmissionV2_Blocklist(t *testing.T) {
 		})
 	}
 }
+
+// This tests payment when the proposer fee recipient receives CL withdrawal.
+func TestValidateBuilderSubmissionV2_ExcludeWithdrawals(t *testing.T) {
+	genesis, preMergeBlocks := generatePreMergeChain(20)
+	lastBlock := preMergeBlocks[len(preMergeBlocks)-1]
+	time := lastBlock.Time() + 5
+	genesis.Config.ShanghaiTime = &time
+	n, ethservice := startEthService(t, genesis, preMergeBlocks)
+	ethservice.Merger().ReachTTD()
+	defer n.Close()
+
+	api := NewBlockValidationAPI(ethservice, nil, true, true)
+
+	baseFee := misc.CalcBaseFee(ethservice.BlockChain().Config(), lastBlock.Header())
+	txs := make(types.Transactions, 0)
+
+	statedb, _ := ethservice.BlockChain().StateAt(lastBlock.Root())
+	nonce := statedb.GetNonce(testAddr)
+	signer := types.LatestSigner(ethservice.BlockChain().Config())
+
+	expectedProfit := uint64(0)
+
+	tx1, _ := types.SignTx(types.NewTransaction(nonce, common.Address{0x16}, big.NewInt(10), 21000, big.NewInt(2*baseFee.Int64()), nil), signer, testKey)
+	txs = append(txs, tx1)
+	expectedProfit += 21000 * baseFee.Uint64()
+
+	// this tx will use 56996 gas
+	tx2, _ := types.SignTx(types.NewContractCreation(nonce+1, new(big.Int), 1000000, big.NewInt(2*baseFee.Int64()), logCode), signer, testKey)
+	txs = append(txs, tx2)
+	expectedProfit += 56996 * baseFee.Uint64()
+
+	tx3, _ := types.SignTx(types.NewTransaction(nonce+2, testAddr, big.NewInt(10), 21000, baseFee, nil), signer, testKey)
+	txs = append(txs, tx3)
+
+	// this transaction sends 7 wei to the proposer fee recipient, this should count as a profit
+	tx4, _ := types.SignTx(types.NewTransaction(nonce+3, testValidatorAddr, big.NewInt(7), 21000, baseFee, nil), signer, testKey)
+	txs = append(txs, tx4)
+	expectedProfit += 7
+
+	withdrawals := []*types.Withdrawal{
+		{
+			Index:     0,
+			Validator: 1,
+			Amount:    100,
+			Address:   testAddr,
+		},
+		{
+			Index:     1,
+			Validator: 1,
+			Amount:    17,
+			Address:   testValidatorAddr,
+		},
+		{
+			Index:     1,
+			Validator: 1,
+			Amount:    21,
+			Address:   testValidatorAddr,
+		},
+	}
+	withdrawalsRoot := types.DeriveSha(types.Withdrawals(withdrawals), trie.NewStackTrie(nil))
+
+	buildBlockArgs := buildBlockArgs{
+		parentHash:    lastBlock.Hash(),
+		parentRoot:    lastBlock.Root(),
+		feeRecipient:  testValidatorAddr,
+		txs:           txs,
+		random:        common.Hash{},
+		number:        lastBlock.NumberU64() + 1,
+		gasLimit:      lastBlock.GasLimit(),
+		timestamp:     lastBlock.Time() + 5,
+		extraData:     nil,
+		baseFeePerGas: baseFee,
+		withdrawals:   withdrawals,
+	}
+
+	execData, err := buildBlock(buildBlockArgs, ethservice.BlockChain())
+	require.NoError(t, err)
+
+	value := big.NewInt(int64(expectedProfit))
+
+	req, err := executableDataToBlockValidationRequest(execData, testValidatorAddr, value, withdrawalsRoot)
+	require.NoError(t, err)
+	require.NoError(t, api.ValidateBuilderSubmissionV2(req))
+
+	// try to claim less profit than expected, should work
+	value.SetUint64(expectedProfit - 1)
+
+	req, err = executableDataToBlockValidationRequest(execData, testValidatorAddr, value, withdrawalsRoot)
+	require.NoError(t, err)
+	require.NoError(t, api.ValidateBuilderSubmissionV2(req))
+
+	// try to claim more profit than expected, should fail
+	value.SetUint64(expectedProfit + 1)
+
+	req, err = executableDataToBlockValidationRequest(execData, testValidatorAddr, value, withdrawalsRoot)
+	require.NoError(t, err)
+	require.ErrorContains(t, api.ValidateBuilderSubmissionV2(req), "payment")
+}