core,miner: implement EIP-7934 - RLP Execution Block Size Limit (#31990)

This PR adds a block validation check for the maximum block size, as required by
EIP-7934, and also applies a slightly lower size limit during block building.

---------

Co-authored-by: spencer-tb <spencer@spencertaylorbrown.uk>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Gary Rong <garyrong0905@gmail.com>

core/block_validator.go

@@ -49,6 +49,10 @@ func NewBlockValidator(config *params.ChainConfig, blockchain *BlockChain) *Bloc
 // header's transaction and uncle roots. The headers are assumed to be already
 // validated at this point.
 func (v *BlockValidator) ValidateBody(block *types.Block) error {
+	// check EIP 7934 RLP-encoded block size cap
+	if v.config.IsOsaka(block.Number(), block.Time()) && block.Size() > params.MaxBlockSize {
+		return ErrBlockOversized
+	}
 	// Check whether the block is already imported.
 	if v.bc.HasBlockAndState(block.Hash(), block.NumberU64()) {
 		return ErrKnownBlock

core/error.go

@@ -28,6 +28,10 @@ var (
 
 	// ErrNoGenesis is returned when there is no Genesis Block.
 	ErrNoGenesis = errors.New("genesis not found in chain")
+
+	// ErrBlockOversized is returned if the size of the RLP-encoded block
+	// exceeds the cap established by EIP 7934
+	ErrBlockOversized = errors.New("block RLP-encoded size exceeds maximum")
 )
 
 // List of evm-call-message pre-checking errors. All state transition messages will

core/types/block_test.go

@@ -24,11 +24,13 @@ import (
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/internal/blocktest"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/holiman/uint256"
 )
 
 // from bcValidBlockTest.json, "SimpleTx"
@@ -194,6 +196,60 @@ func TestEIP2718BlockEncoding(t *testing.T) {
 	}
 }
 
+func TestEIP4844BlockEncoding(t *testing.T) {
+	// https://github.com/ethereum/tests/blob/develop/BlockchainTests/ValidBlocks/bcEIP4844-blobtransactions/blockWithAllTransactionTypes.json
+	blockEnc := common.FromHex("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")
+	var block Block
+	if err := rlp.DecodeBytes(blockEnc, &block); err != nil {
+		t.Fatal("decode error: ", err)
+	}
+
+	check := func(f string, got, want interface{}) {
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("%s mismatch: got %v, want %v", f, got, want)
+		}
+	}
+	check("Difficulty", block.Difficulty(), big.NewInt(0))
+	check("GasLimit", block.GasLimit(), hexutil.MustDecodeUint64("0x16345785d8a0000"))
+	check("GasUsed", block.GasUsed(), hexutil.MustDecodeUint64("0x14820"))
+	check("Coinbase", block.Coinbase(), common.HexToAddress("0xba5e000000000000000000000000000000000000"))
+	check("MixDigest", block.MixDigest(), common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000020000"))
+	check("Root", block.Root(), common.HexToHash("0x11639dcca0b44f2acb5b630a82c8a69cb82742b3711383ec4e111a554d27aea5"))
+	check("WithdrawalRoot", *block.Header().WithdrawalsHash, common.HexToHash("0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421"))
+	check("Nonce", block.Nonce(), uint64(0))
+	check("Time", block.Time(), hexutil.MustDecodeUint64("0x79e"))
+	check("Size", block.Size(), uint64(len(blockEnc)))
+
+	// Create blob tx.
+	tx := NewTx(&BlobTx{
+		ChainID:    uint256.NewInt(1),
+		Nonce:      3,
+		To:         common.HexToAddress("0x100000000000000000000000000000000000000a"),
+		Gas:        hexutil.MustDecodeUint64("0xe8d4a51000"),
+		GasTipCap:  uint256.MustFromHex("0x1"),
+		GasFeeCap:  uint256.MustFromHex("0x3e8"),
+		BlobFeeCap: uint256.MustFromHex("0xa"),
+		BlobHashes: []common.Hash{
+			common.BytesToHash(hexutil.MustDecode("0x01a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8")),
+		},
+		Value: uint256.MustFromHex("0x7"),
+	})
+	sig := common.Hex2Bytes("00638144c46d5de7a9e630c0e7c5c63ae829ecfd8cc94715d9c29fe17c464de06c5fc54c3aa868ba35ef31a4e12431611631ab7bcdceb4214dd273d83f73b5e100")
+	tx, _ = tx.WithSignature(LatestSignerForChainID(big.NewInt(1)), sig)
+
+	check("len(Transactions)", len(block.Transactions()), 4)
+	check("Transactions[3].Hash", block.Transactions()[3].Hash(), tx.Hash())
+	check("Transactions[3].Type()", block.Transactions()[3].Type(), uint8(BlobTxType))
+
+	ourBlockEnc, err := rlp.EncodeToBytes(&block)
+	if err != nil {
+		t.Fatal("encode error: ", err)
+	}
+	if !bytes.Equal(ourBlockEnc, blockEnc) {
+		t.Errorf("encoded block mismatch:\ngot:  %x\nwant: %x", ourBlockEnc, blockEnc)
+	}
+}
+
 func TestUncleHash(t *testing.T) {
 	uncles := make([]*Header, 0)
 	h := CalcUncleHash(uncles)

core/types/transaction.go

@@ -449,14 +449,18 @@ func (tx *Transaction) BlobGasFeeCapIntCmp(other *big.Int) int {
 // WithoutBlobTxSidecar returns a copy of tx with the blob sidecar removed.
 func (tx *Transaction) WithoutBlobTxSidecar() *Transaction {
 	blobtx, ok := tx.inner.(*BlobTx)
-	if !ok {
+	if !ok || blobtx.Sidecar == nil {
 		return tx
 	}
 	cpy := &Transaction{
 		inner: blobtx.withoutSidecar(),
 		time:  tx.time,
 	}
-	// Note: tx.size cache not carried over because the sidecar is included in size!
+	if size := tx.size.Load(); size != 0 {
+		// The tx had a sidecar before, so we need to subtract it from the size.
+		scSize := rlp.ListSize(blobtx.Sidecar.encodedSize())
+		cpy.size.Store(size - scSize)
+	}
 	if h := tx.hash.Load(); h != nil {
 		cpy.hash.Store(h)
 	}

miner/worker.go

@@ -50,6 +50,7 @@ type environment struct {
 	signer   types.Signer
 	state    *state.StateDB // apply state changes here
 	tcount   int            // tx count in cycle
+	size     uint64         // size of the block we are building
 	gasPool  *core.GasPool  // available gas used to pack transactions
 	coinbase common.Address
 	evm      *vm.EVM
@@ -63,6 +64,11 @@ type environment struct {
 	witness *stateless.Witness
 }
 
+// txFits reports whether the transaction fits into the block size limit.
+func (env *environment) txFitsSize(tx *types.Transaction) bool {
+	return env.size+tx.Size() < params.MaxBlockSize-maxBlockSizeBufferZone
+}
+
 const (
 	commitInterruptNone int32 = iota
 	commitInterruptNewHead
@@ -70,6 +76,11 @@ const (
 	commitInterruptTimeout
 )
 
+// Block size is capped by the protocol at params.MaxBlockSize. When producing blocks, we
+// try to say below the size including a buffer zone, this is to avoid going over the
+// maximum size with auxiliary data added into the block.
+const maxBlockSizeBufferZone = 1_000_000
+
 // newPayloadResult is the result of payload generation.
 type newPayloadResult struct {
 	err      error
@@ -95,12 +106,23 @@ type generateParams struct {
 }
 
 // generateWork generates a sealing block based on the given parameters.
-func (miner *Miner) generateWork(params *generateParams, witness bool) *newPayloadResult {
-	work, err := miner.prepareWork(params, witness)
+func (miner *Miner) generateWork(genParam *generateParams, witness bool) *newPayloadResult {
+	work, err := miner.prepareWork(genParam, witness)
 	if err != nil {
 		return &newPayloadResult{err: err}
 	}
-	if !params.noTxs {
+
+	// Check withdrawals fit max block size.
+	// Due to the cap on withdrawal count, this can actually never happen, but we still need to
+	// check to ensure the CL notices there's a problem if the withdrawal cap is ever lifted.
+	maxBlockSize := params.MaxBlockSize - maxBlockSizeBufferZone
+	if genParam.withdrawals.Size() > maxBlockSize {
+		return &newPayloadResult{err: errors.New("withdrawals exceed max block size")}
+	}
+	// Also add size of withdrawals to work block size.
+	work.size += uint64(genParam.withdrawals.Size())
+
+	if !genParam.noTxs {
 		interrupt := new(atomic.Int32)
 		timer := time.AfterFunc(miner.config.Recommit, func() {
 			interrupt.Store(commitInterruptTimeout)
@@ -112,8 +134,8 @@ func (miner *Miner) generateWork(params *generateParams, witness bool) *newPaylo
 			log.Warn("Block building is interrupted", "allowance", common.PrettyDuration(miner.config.Recommit))
 		}
 	}
+	body := types.Body{Transactions: work.txs, Withdrawals: genParam.withdrawals}
 
-	body := types.Body{Transactions: work.txs, Withdrawals: params.withdrawals}
 	allLogs := make([]*types.Log, 0)
 	for _, r := range work.receipts {
 		allLogs = append(allLogs, r.Logs...)
@@ -256,6 +278,7 @@ func (miner *Miner) makeEnv(parent *types.Header, header *types.Header, coinbase
 	return &environment{
 		signer:   types.MakeSigner(miner.chainConfig, header.Number, header.Time),
 		state:    state,
+		size:     uint64(header.Size()),
 		coinbase: coinbase,
 		header:   header,
 		witness:  state.Witness(),
@@ -273,6 +296,7 @@ func (miner *Miner) commitTransaction(env *environment, tx *types.Transaction) e
 	}
 	env.txs = append(env.txs, tx)
 	env.receipts = append(env.receipts, receipt)
+	env.size += tx.Size()
 	env.tcount++
 	return nil
 }
@@ -294,10 +318,12 @@ func (miner *Miner) commitBlobTransaction(env *environment, tx *types.Transactio
 	if err != nil {
 		return err
 	}
-	env.txs = append(env.txs, tx.WithoutBlobTxSidecar())
+	txNoBlob := tx.WithoutBlobTxSidecar()
+	env.txs = append(env.txs, txNoBlob)
 	env.receipts = append(env.receipts, receipt)
 	env.sidecars = append(env.sidecars, sc)
 	env.blobs += len(sc.Blobs)
+	env.size += txNoBlob.Size()
 	*env.header.BlobGasUsed += receipt.BlobGasUsed
 	env.tcount++
 	return nil
@@ -318,7 +344,11 @@ func (miner *Miner) applyTransaction(env *environment, tx *types.Transaction) (*
 }
 
 func (miner *Miner) commitTransactions(env *environment, plainTxs, blobTxs *transactionsByPriceAndNonce, interrupt *atomic.Int32) error {
-	gasLimit := env.header.GasLimit
+	var (
+		isOsaka  = miner.chainConfig.IsOsaka(env.header.Number, env.header.Time)
+		isCancun = miner.chainConfig.IsCancun(env.header.Number, env.header.Time)
+		gasLimit = env.header.GasLimit
+	)
 	if env.gasPool == nil {
 		env.gasPool = new(core.GasPool).AddGas(gasLimit)
 	}
@@ -374,7 +404,7 @@ func (miner *Miner) commitTransactions(env *environment, plainTxs, blobTxs *tran
 		// Most of the blob gas logic here is agnostic as to if the chain supports
 		// blobs or not, however the max check panics when called on a chain without
 		// a defined schedule, so we need to verify it's safe to call.
-		if miner.chainConfig.IsCancun(env.header.Number, env.header.Time) {
+		if isCancun {
 			left := eip4844.MaxBlobsPerBlock(miner.chainConfig, env.header.Time) - env.blobs
 			if left < int(ltx.BlobGas/params.BlobTxBlobGasPerBlob) {
 				log.Trace("Not enough blob space left for transaction", "hash", ltx.Hash, "left", left, "needed", ltx.BlobGas/params.BlobTxBlobGasPerBlob)
@@ -391,8 +421,14 @@ func (miner *Miner) commitTransactions(env *environment, plainTxs, blobTxs *tran
 			continue
 		}
 
+		// if inclusion of the transaction would put the block size over the
+		// maximum we allow, don't add any more txs to the payload.
+		if !env.txFitsSize(tx) {
+			break
+		}
+
 		// Make sure all transactions after osaka have cell proofs
-		if miner.chainConfig.IsOsaka(env.header.Number, env.header.Time) {
+		if isOsaka {
 			if sidecar := tx.BlobTxSidecar(); sidecar != nil {
 				if sidecar.Version == 0 {
 					log.Info("Including blob tx with v0 sidecar, recomputing proofs", "hash", ltx.Hash)

params/protocol_params.go

@@ -180,6 +180,8 @@ const (
 	BlobBaseCost                       = 1 << 13 // Base execution gas cost for a blob.
 
 	HistoryServeWindow = 8192 // Number of blocks to serve historical block hashes for, EIP-2935.
+
+	MaxBlockSize = 8_388_608 // maximum size of an RLP-encoded block
 )
 
 // Bls12381G1MultiExpDiscountTable is the gas discount table for BLS12-381 G1 multi exponentiation operation