feat: add tx data version byte (#9845)

* feat: add tx data version byte

* fix: check data len before version byte

* avoid passing version byte

op-batcher/batcher/driver.go

@@ -400,7 +400,8 @@ func (l *BatchSubmitter) sendTransaction(ctx context.Context, txdata txData, que
 				l.recordFailedTx(txdata, err)
 				return nil
 			}
-			data = comm.Encode()
+			// signal plasma commitment tx with TxDataVersion1
+			data = comm.TxData()
 		}
 		candidate = l.calldataTxCandidate(data)
 	}

op-e2e/actions/l2_batcher.go

@@ -253,7 +253,7 @@ func (s *L2Batcher) ActL2BatchSubmit(t Testing, txOpts ...func(tx *types.Dynamic
 	if s.l2BatcherCfg.UsePlasma {
 		comm, err := s.l2BatcherCfg.PlasmaDA.SetInput(t.Ctx(), payload)
 		require.NoError(t, err, "failed to set input for plasma")
-		payload = comm.Encode()
+		payload = comm.TxData()
 	}
 
 	nonce, err := s.l1.PendingNonceAt(t.Ctx(), s.batcherAddr)

op-e2e/actions/plasma_test.go

@@ -159,7 +159,8 @@ func (a *L2PlasmaDA) ActNewL2Tx(t Testing) {
 	a.batcher.ActL2BatchBuffer(t)
 	a.batcher.ActL2ChannelClose(t)
 	a.batcher.ActL2BatchSubmit(t, func(tx *types.DynamicFeeTx) {
-		a.lastComm = tx.Data
+		// skip txdata version byte
+		a.lastComm = tx.Data[1:]
 	})
 
 	a.miner.ActL1StartBlock(3)(t)

op-node/rollup/derive/params.go

@@ -4,6 +4,8 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+
+	plasma "github.com/ethereum-optimism/optimism/op-plasma"
 )
 
 // count the tagging info as 200 in terms of buffer size.
@@ -19,6 +21,9 @@ func frameSize(frame Frame) uint64 {
 
 const DerivationVersion0 = 0
 
+// DerivationVersion1 is reserved for batcher transactions containing plasma commitments.
+const DerivationVersion1 = plasma.TxDataVersion1
+
 // MaxSpanBatchSize is the maximum amount of bytes that will be needed
 // to decode every span batch field. This value cannot be larger than
 // MaxRLPBytesPerChannel because single batch cannot be larger than channel size.

op-node/rollup/derive/plasma_data_source.go

@@ -45,14 +45,22 @@ func (s *PlasmaDataSource) Next(ctx context.Context) (eth.Data, error) {
 	}
 
 	if s.comm == nil {
-		var err error
 		// the l1 source returns the input commitment for the batch.
 		data, err := s.src.Next(ctx)
 		if err != nil {
 			return nil, err
 		}
+		if len(data) == 0 {
+			return nil, NotEnoughData
+		}
+		// If the tx data type is not plasma, we forward it downstream to let the next
+		// steps validate and potentially parse it as L1 DA inputs.
+		if data[0] != plasma.TxDataVersion1 {
+			return data, nil
+		}
+
 		// validate batcher inbox data is a commitment.
-		comm, err := plasma.DecodeKeccak256(data)
+		comm, err := plasma.DecodeKeccak256(data[1:])
 		if err != nil {
 			s.log.Warn("invalid commitment", "commitment", data, "err", err)
 			return s.Next(ctx)

op-node/rollup/derive/plasma_data_source_test.go

@@ -134,7 +134,7 @@ func TestPlasmaDataSource(t *testing.T) {
 				Gas:       100_000,
 				To:        &batcherInbox,
 				Value:     big.NewInt(int64(0)),
-				Data:      comm.Encode(),
+				Data:      comm.TxData(),
 			})
 			require.NoError(t, err)
 
@@ -234,7 +234,7 @@ func TestPlasmaDataSource(t *testing.T) {
 					Gas:       100_000,
 					To:        &batcherInbox,
 					Value:     big.NewInt(int64(0)),
-					Data:      comm.Encode(),
+					Data:      comm.TxData(),
 				})
 				require.NoError(t, err)
 
@@ -351,7 +351,7 @@ func TestPlasmaDataSourceStall(t *testing.T) {
 		Gas:       100_000,
 		To:        &batcherInbox,
 		Value:     big.NewInt(int64(0)),
-		Data:      comm.Encode(),
+		Data:      comm.TxData(),
 	})
 	require.NoError(t, err)
 
@@ -466,7 +466,7 @@ func TestPlasmaDataSourceInvalidData(t *testing.T) {
 		Gas:       100_000,
 		To:        &batcherInbox,
 		Value:     big.NewInt(int64(0)),
-		Data:      comm.Encode(),
+		Data:      comm.TxData(),
 	})
 	require.NoError(t, err)
 
@@ -481,11 +481,11 @@ func TestPlasmaDataSourceInvalidData(t *testing.T) {
 		Gas:       100_000,
 		To:        &batcherInbox,
 		Value:     big.NewInt(int64(0)),
-		Data:      comm2.Encode(),
+		Data:      comm2.TxData(),
 	})
 	require.NoError(t, err)
 
-	// invalid commitment
+	// regular input instead of commitment
 	input3 := testutils.RandomData(rng, 32)
 	tx3, err := types.SignNewTx(batcherPriv, signer, &types.DynamicFeeTx{
 		ChainID:   signer.ChainID(),
@@ -506,12 +506,16 @@ func TestPlasmaDataSourceInvalidData(t *testing.T) {
 	src, err := factory.OpenData(ctx, ref, batcherAddr)
 	require.NoError(t, err)
 
-	// oversized input should be skipped
+	// oversized input is skipped and returns input2 directly
 	data, err := src.Next(ctx)
 	require.NoError(t, err)
 	require.Equal(t, hexutil.Bytes(input2), data)
 
-	// invalid commitment is skipped so should return an EOF
+	// regular input is passed through
+	data, err = src.Next(ctx)
+	require.NoError(t, err)
+	require.Equal(t, hexutil.Bytes(input3), data)
+
 	_, err = src.Next(ctx)
 	require.ErrorIs(t, err, io.EOF)
 

op-plasma/commitment.go

@@ -27,6 +27,11 @@ func (c Keccak256Commitment) Encode() []byte {
 	return append([]byte{byte(Keccak256CommitmentType)}, c...)
 }
 
+// TxData adds an extra version byte to signal it's a commitment.
+func (c Keccak256Commitment) TxData() []byte {
+	return append([]byte{TxDataVersion1}, c.Encode()...)
+}
+
 // Verify checks if the commitment matches the given input.
 func (c Keccak256Commitment) Verify(input []byte) error {
 	if !bytes.Equal(c, crypto.Keccak256(input)) {

op-plasma/params.go

@@ -4,3 +4,8 @@ package plasma
 // challenge in the Data Availability Challenge contract. Value in number of bytes.
 // This value can only be changed in a hard fork.
 const MaxInputSize = 130672
+
+// TxDataVersion1 is the version number for batcher transactions containing
+// plasma commitments. It should not collide with DerivationVersion which is still
+// used downstream when parsing the frames.
+const TxDataVersion1 = 1