op-node: split l1 source into eth and l1 client (#3288)

* op-node: split l1 source into eth and l1 client

* op-node: fix comment typo
Co-authored-by: Javed Khan <javed@optimism.io>

* op-node: implement l1 rpc review suggestions
Co-authored-by: Javed Khan <javed@optimism.io>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

op-node/l2/util.go → op-node/eth/account_proof.go

-package l2
+package eth
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"math/big"
 
-	"github.com/ethereum-optimism/optimism/op-node/eth"
-
-	"github.com/ethereum-optimism/optimism/op-node/rollup"
-	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
-	"github.com/ethereum/go-ethereum/core/types"
-
-	"github.com/ethereum/go-ethereum/ethdb/memorydb"
-
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/rlp"
-
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
 )
 
-func ComputeL2OutputRoot(l2OutputRootVersion eth.Bytes32, blockHash common.Hash, blockRoot common.Hash, storageRoot common.Hash) eth.Bytes32 {
-	var buf bytes.Buffer
-	buf.Write(l2OutputRootVersion[:])
-	buf.Write(blockRoot.Bytes())
-	buf.Write(storageRoot[:])
-	buf.Write(blockHash.Bytes())
-	return eth.Bytes32(crypto.Keccak256Hash(buf.Bytes()))
-}
-
 type AccountResult struct {
 	AccountProof []hexutil.Bytes `json:"accountProof"`
 
@@ -82,40 +64,3 @@ func (res *AccountResult) Verify(stateRoot common.Hash) error {
 	}
 	return err
 }
-
-// BlockToBatch converts a L2 block to batch-data.
-// Invalid L2 blocks may return an error.
-func BlockToBatch(config *rollup.Config, block *types.Block) (*derive.BatchData, error) {
-	txs := block.Transactions()
-	if len(txs) == 0 {
-		return nil, errors.New("expected at least 1 transaction but found none")
-	}
-	if typ := txs[0].Type(); typ != types.DepositTxType {
-		return nil, fmt.Errorf("expected first tx to be a deposit of L1 info, but got type: %d", typ)
-	}
-
-	// encode non-deposit transactions
-	var opaqueTxs []hexutil.Bytes
-	for i, tx := range block.Transactions() {
-		if tx.Type() == types.DepositTxType {
-			continue
-		}
-		otx, err := tx.MarshalBinary()
-		if err != nil {
-			return nil, fmt.Errorf("failed to encode tx %d in block: %v", i, err)
-		}
-		opaqueTxs = append(opaqueTxs, otx)
-	}
-
-	// figure out which L1 epoch this L2 block was derived from
-	l1Info, err := derive.L1InfoDepositTxData(txs[0].Data())
-	if err != nil {
-		return nil, fmt.Errorf("invalid L1 info deposit tx in block: %v", err)
-	}
-	return &derive.BatchData{BatchV1: derive.BatchV1{
-		EpochNum:     rollup.Epoch(l1Info.Number), // the L1 block number equals the L2 epoch.
-		EpochHash:    l1Info.BlockHash,
-		Timestamp:    block.Time(),
-		Transactions: opaqueTxs,
-	}}, nil
-}

op-node/eth/l1info.go → op-node/eth/block_info.go

@@ -6,9 +6,10 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 )
 
-type L1Info interface {
+type BlockInfo interface {
 	Hash() common.Hash
 	ParentHash() common.Hash
+	Coinbase() common.Address
 	Root() common.Hash // state-root
 	NumberU64() uint64
 	Time() uint64
@@ -16,6 +17,14 @@ type L1Info interface {
 	MixDigest() common.Hash
 	BaseFee() *big.Int
 	ID() BlockID
-	BlockRef() L1BlockRef
 	ReceiptHash() common.Hash
 }
+
+func InfoToL1BlockRef(info BlockInfo) L1BlockRef {
+	return L1BlockRef{
+		Hash:       info.Hash(),
+		Number:     info.NumberU64(),
+		ParentHash: info.ParentHash(),
+		Time:       info.Time(),
+	}
+}

op-node/eth/label.go

+package eth
+
+type BlockLabel string
+
+const (
+	// Unsafe is:
+	// - L1: absolute head of the chain
+	// - L2: absolute head of the chain, not confirmed on L1
+	Unsafe = "latest"
+	// Safe is:
+	// - L1: Justified checkpoint, beacon chain: 1 epoch of 2/3 of the validators attesting the epoch.
+	// - L2: Derived chain tip from L1 data
+	Safe = "safe"
+	// Finalized is:
+	// - L1: Finalized checkpoint, beacon chain: 2+ justified epochs with "supermajority link" (see FFG docs).
+	//       More about FFG: https://ethereum.org/en/developers/docs/consensus-mechanisms/pos/gasper/
+	// - L2: Derived chain tip from finalized L1 data
+	Finalized = "finalized"
+)

op-node/l2/source.go

@@ -250,8 +250,8 @@ func (s *ReadOnlySource) GetBlockHeader(ctx context.Context, blockTag string) (*
 	return head, err
 }
 
-func (s *ReadOnlySource) GetProof(ctx context.Context, address common.Address, blockTag string) (*AccountResult, error) {
-	var getProofResponse *AccountResult
+func (s *ReadOnlySource) GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error) {
+	var getProofResponse *eth.AccountResult
 	err := s.rpc.CallContext(ctx, &getProofResponse, "eth_getProof", address, []common.Hash{}, blockTag)
 	if err == nil && getProofResponse == nil {
 		err = ethereum.NotFound

op-node/node/api.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
 	"github.com/ethereum-optimism/optimism/op-node/eth"
-	"github.com/ethereum-optimism/optimism/op-node/l2"
 	"github.com/ethereum-optimism/optimism/op-node/metrics"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/rollup/driver"
@@ -23,7 +22,7 @@ import (
 type l2EthClient interface {
 	GetBlockHeader(ctx context.Context, blockTag string) (*types.Header, error)
 	// GetProof returns a proof of the account, it may return a nil result without error if the address was not found.
-	GetProof(ctx context.Context, address common.Address, blockTag string) (*l2.AccountResult, error)
+	GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error)
 
 	BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error)
 	L2BlockRefByNumber(ctx context.Context, l2Num *big.Int) (eth.L2BlockRef, error)
@@ -100,7 +99,7 @@ func (n *nodeAPI) OutputAtBlock(ctx context.Context, number rpc.BlockNumber) ([]
 	}
 
 	var l2OutputRootVersion eth.Bytes32 // it's zero for now
-	l2OutputRoot := l2.ComputeL2OutputRoot(l2OutputRootVersion, head.Hash(), head.Root, proof.StorageHash)
+	l2OutputRoot := rollup.ComputeL2OutputRoot(l2OutputRootVersion, head.Hash(), head.Root, proof.StorageHash)
 
 	return []eth.Bytes32{l2OutputRootVersion, l2OutputRoot}, nil
 }

op-node/node/node.go

@@ -11,11 +11,11 @@ import (
 
 	"github.com/ethereum-optimism/optimism/op-node/client"
 	"github.com/ethereum-optimism/optimism/op-node/eth"
-	"github.com/ethereum-optimism/optimism/op-node/l1"
 	"github.com/ethereum-optimism/optimism/op-node/l2"
 	"github.com/ethereum-optimism/optimism/op-node/metrics"
 	"github.com/ethereum-optimism/optimism/op-node/p2p"
 	"github.com/ethereum-optimism/optimism/op-node/rollup/driver"
+	"github.com/ethereum-optimism/optimism/op-node/sources"
 
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/event"
@@ -27,7 +27,7 @@ type OpNode struct {
 	appVersion string
 	metrics    *metrics.Metrics
 	l1HeadsSub ethereum.Subscription // Subscription to get L1 heads (automatically re-subscribes on error)
-	l1Source   *l1.Source            // Source to fetch data from (also implements the Downloader interface)
+	l1Source   *sources.L1Client     // L1 Client to fetch data from
 	l2Engine   *driver.Driver        // L2 Engine to Sync
 	l2Node     client.RPC            // L2 Execution Engine RPC connections to close at shutdown
 	l2Client   client.Client         // L2 client wrapper around eth namespace
@@ -110,7 +110,9 @@ func (n *OpNode) initL1(ctx context.Context, cfg *Config) error {
 		return fmt.Errorf("failed to get L1 RPC client: %w", err)
 	}
 
-	n.l1Source, err = l1.NewSource(client.NewInstrumentedRPC(l1Node, n.metrics), n.metrics.L1SourceCache, l1.DefaultConfig(&cfg.Rollup, trustRPC))
+	n.l1Source, err = sources.NewL1Client(
+		client.NewInstrumentedRPC(l1Node, n.metrics), n.log, n.metrics.L1SourceCache,
+		sources.L1ClientDefaultConfig(&cfg.Rollup, trustRPC))
 	if err != nil {
 		return fmt.Errorf("failed to create L1 source: %v", err)
 	}

op-node/node/server_test.go

@@ -6,6 +6,8 @@ import (
 	"math/big"
 	"math/rand"
 
+	"github.com/ethereum/go-ethereum/common"
+
 	"github.com/ethereum-optimism/optimism/op-node/rollup/driver"
 	"github.com/ethereum-optimism/optimism/op-node/testutils"
 
@@ -23,8 +25,6 @@ import (
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/stretchr/testify/mock"
 
-	"github.com/ethereum-optimism/optimism/op-node/l2"
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/stretchr/testify/assert"
@@ -76,7 +76,7 @@ func TestOutputAtBlock(t *testing.T) {
 		"nonce": "0x1",
 		"storageHash": "0xc1917a80cb25ccc50d0d1921525a44fb619b4601194ca726ae32312f08a799f8"
 	}`
-	var result l2.AccountResult
+	var result eth.AccountResult
 	err = json.Unmarshal([]byte(resultTestData), &result)
 	assert.NoError(t, err)
 
@@ -201,6 +201,6 @@ func (c *mockL2Client) GetBlockHeader(ctx context.Context, blockTag string) (*ty
 	return c.mock.MethodCalled("GetBlockHeader", blockTag).Get(0).(*types.Header), nil
 }
 
-func (c *mockL2Client) GetProof(ctx context.Context, address common.Address, blockTag string) (*l2.AccountResult, error) {
-	return c.mock.MethodCalled("GetProof", address, blockTag).Get(0).(*l2.AccountResult), nil
+func (c *mockL2Client) GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error) {
+	return c.mock.MethodCalled("GetProof", address, blockTag).Get(0).(*eth.AccountResult), nil
 }

op-node/rollup/derive/attributes.go

@@ -14,8 +14,8 @@ import (
 
 // L1ReceiptsFetcher fetches L1 header info and receipts for the payload attributes derivation (the info tx and deposits)
 type L1ReceiptsFetcher interface {
-	InfoByHash(ctx context.Context, hash common.Hash) (eth.L1Info, error)
-	Fetch(ctx context.Context, blockHash common.Hash) (eth.L1Info, types.Transactions, eth.ReceiptsFetcher, error)
+	InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error)
+	Fetch(ctx context.Context, blockHash common.Hash) (eth.BlockInfo, types.Transactions, eth.ReceiptsFetcher, error)
 }
 
 // PreparePayloadAttributes prepares a PayloadAttributes template that is ready to build a L2 block with deposits only, on top of the given l2Parent, with the given epoch as L1 origin.
@@ -24,7 +24,7 @@ type L1ReceiptsFetcher interface {
 // The severity of the error is returned; a crit=false error means there was a temporary issue, like a failed RPC or time-out.
 // A crit=true error means the input arguments are inconsistent or invalid.
 func PreparePayloadAttributes(ctx context.Context, cfg *rollup.Config, dl L1ReceiptsFetcher, l2Parent eth.L2BlockRef, timestamp uint64, epoch eth.BlockID) (attrs *eth.PayloadAttributes, err error) {
-	var l1Info eth.L1Info
+	var l1Info eth.BlockInfo
 	var depositTxs []hexutil.Bytes
 	var seqNumber uint64
 

op-node/rollup/derive/attributes_queue_test.go

@@ -48,7 +48,7 @@ func TestAttributesQueue_Step(t *testing.T) {
 		DepositContractAddress: common.Address{0xbb},
 	}
 	rng := rand.New(rand.NewSource(1234))
-	l1Info := testutils.RandomL1Info(rng)
+	l1Info := testutils.RandomBlockInfo(rng)
 
 	l1Fetcher := &testutils.MockL1Source{}
 	defer l1Fetcher.AssertExpectations(t)

op-node/rollup/derive/attributes_test.go

@@ -32,7 +32,7 @@ func TestPreparePayloadAttributes(t *testing.T) {
 		defer l1Fetcher.AssertExpectations(t)
 		l2Parent := testutils.RandomL2BlockRef(rng)
 		l2Time := l2Parent.Time + cfg.BlockTime
-		l1Info := testutils.RandomL1Info(rng)
+		l1Info := testutils.RandomBlockInfo(rng)
 		l1Info.InfoNum = l2Parent.L1Origin.Number + 1
 		epoch := l1Info.ID()
 		l1Fetcher.ExpectFetch(epoch.Hash, l1Info, nil, nil, nil)
@@ -46,7 +46,7 @@ func TestPreparePayloadAttributes(t *testing.T) {
 		defer l1Fetcher.AssertExpectations(t)
 		l2Parent := testutils.RandomL2BlockRef(rng)
 		l2Time := l2Parent.Time + cfg.BlockTime
-		l1Info := testutils.RandomL1Info(rng)
+		l1Info := testutils.RandomBlockInfo(rng)
 		l1Info.InfoNum = l2Parent.L1Origin.Number
 		epoch := l1Info.ID()
 		_, err := PreparePayloadAttributes(context.Background(), cfg, l1Fetcher, l2Parent, l2Time, epoch)
@@ -86,7 +86,7 @@ func TestPreparePayloadAttributes(t *testing.T) {
 		defer l1Fetcher.AssertExpectations(t)
 		l2Parent := testutils.RandomL2BlockRef(rng)
 		l2Time := l2Parent.Time + cfg.BlockTime
-		l1Info := testutils.RandomL1Info(rng)
+		l1Info := testutils.RandomBlockInfo(rng)
 		l1Info.InfoParentHash = l2Parent.L1Origin.Hash
 		l1Info.InfoNum = l2Parent.L1Origin.Number + 1
 		epoch := l1Info.ID()
@@ -109,7 +109,7 @@ func TestPreparePayloadAttributes(t *testing.T) {
 		defer l1Fetcher.AssertExpectations(t)
 		l2Parent := testutils.RandomL2BlockRef(rng)
 		l2Time := l2Parent.Time + cfg.BlockTime
-		l1Info := testutils.RandomL1Info(rng)
+		l1Info := testutils.RandomBlockInfo(rng)
 		l1Info.InfoParentHash = l2Parent.L1Origin.Hash
 		l1Info.InfoNum = l2Parent.L1Origin.Number + 1
 
@@ -147,7 +147,7 @@ func TestPreparePayloadAttributes(t *testing.T) {
 		defer l1Fetcher.AssertExpectations(t)
 		l2Parent := testutils.RandomL2BlockRef(rng)
 		l2Time := l2Parent.Time + cfg.BlockTime
-		l1Info := testutils.RandomL1Info(rng)
+		l1Info := testutils.RandomBlockInfo(rng)
 		l1Info.InfoHash = l2Parent.L1Origin.Hash
 		l1Info.InfoNum = l2Parent.L1Origin.Number
 

op-node/rollup/derive/calldata_source.go

@@ -18,7 +18,7 @@ import (
 //
 
 type L1TransactionFetcher interface {
-	InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.L1Info, types.Transactions, error)
+	InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, types.Transactions, error)
 }
 
 type DataSlice []eth.Data

op-node/rollup/derive/calldata_source_test.go

@@ -71,7 +71,7 @@ func (ct *calldataTest) Run(t *testing.T, setup *calldataTestSetup) {
 		}
 	}
 
-	info := testutils.RandomL1Info(rng)
+	info := testutils.RandomBlockInfo(rng)
 	l1Src.ExpectInfoAndTxsByHash(info.Hash(), info, txs, ct.err)
 
 	defer l1Src.Mock.AssertExpectations(t)

op-node/rollup/derive/l1_block_info.go

@@ -85,7 +85,7 @@ func L1InfoDepositTxData(data []byte) (L1BlockInfo, error) {
 
 // L1InfoDeposit creates a L1 Info deposit transaction based on the L1 block,
 // and the L2 block-height difference with the start of the epoch.
-func L1InfoDeposit(seqNumber uint64, block eth.L1Info) (*types.DepositTx, error) {
+func L1InfoDeposit(seqNumber uint64, block eth.BlockInfo) (*types.DepositTx, error) {
 	infoDat := L1BlockInfo{
 		Number:         block.NumberU64(),
 		Time:           block.Time(),
@@ -117,7 +117,7 @@ func L1InfoDeposit(seqNumber uint64, block eth.L1Info) (*types.DepositTx, error)
 }
 
 // L1InfoDepositBytes returns a serialized L1-info attributes transaction.
-func L1InfoDepositBytes(seqNumber uint64, l1Info eth.L1Info) ([]byte, error) {
+func L1InfoDepositBytes(seqNumber uint64, l1Info eth.BlockInfo) ([]byte, error) {
 	dep, err := L1InfoDeposit(seqNumber, l1Info)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create L1 info tx: %v", err)

op-node/rollup/derive/l1_block_info_test.go

@@ -12,39 +12,47 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var _ eth.L1Info = (*testutils.MockL1Info)(nil)
+var _ eth.BlockInfo = (*testutils.MockBlockInfo)(nil)
 
 type infoTest struct {
 	name   string
-	mkInfo func(rng *rand.Rand) *testutils.MockL1Info
+	mkInfo func(rng *rand.Rand) *testutils.MockBlockInfo
+	seqNr  func(rng *rand.Rand) uint64
 }
 
 var MockDepositContractAddr = common.HexToAddress("0xdeadbeefdeadbeefdeadbeefdeadbeef00000000")
 
 func TestParseL1InfoDepositTxData(t *testing.T) {
+	randomSeqNr := func(rng *rand.Rand) uint64 {
+		return rng.Uint64()
+	}
 	// Go 1.18 will have native fuzzing for us to use, until then, we cover just the below cases
 	cases := []infoTest{
-		{"random", testutils.MakeL1Info(nil)},
-		{"zero basefee", testutils.MakeL1Info(func(l *testutils.MockL1Info) {
+		{"random", testutils.MakeBlockInfo(nil), randomSeqNr},
+		{"zero basefee", testutils.MakeBlockInfo(func(l *testutils.MockBlockInfo) {
 			l.InfoBaseFee = new(big.Int)
-		})},
-		{"zero time", testutils.MakeL1Info(func(l *testutils.MockL1Info) {
+		}), randomSeqNr},
+		{"zero time", testutils.MakeBlockInfo(func(l *testutils.MockBlockInfo) {
 			l.InfoTime = 0
-		})},
-		{"zero num", testutils.MakeL1Info(func(l *testutils.MockL1Info) {
+		}), randomSeqNr},
+		{"zero num", testutils.MakeBlockInfo(func(l *testutils.MockBlockInfo) {
 			l.InfoNum = 0
-		})},
-		{"zero seq", testutils.MakeL1Info(func(l *testutils.MockL1Info) {
-			l.InfoSequenceNumber = 0
-		})},
-		{"all zero", func(rng *rand.Rand) *testutils.MockL1Info {
-			return &testutils.MockL1Info{InfoBaseFee: new(big.Int)}
+		}), randomSeqNr},
+		{"zero seq", testutils.MakeBlockInfo(nil), func(rng *rand.Rand) uint64 {
+			return 0
+		}},
+		{"all zero", func(rng *rand.Rand) *testutils.MockBlockInfo {
+			return &testutils.MockBlockInfo{InfoBaseFee: new(big.Int)}
+		}, func(rng *rand.Rand) uint64 {
+			return 0
 		}},
 	}
 	for i, testCase := range cases {
 		t.Run(testCase.name, func(t *testing.T) {
-			info := testCase.mkInfo(rand.New(rand.NewSource(int64(1234 + i))))
-			depTx, err := L1InfoDeposit(info.SequenceNumber(), info)
+			rng := rand.New(rand.NewSource(int64(1234 + i)))
+			info := testCase.mkInfo(rng)
+			seqNr := testCase.seqNr(rng)
+			depTx, err := L1InfoDeposit(seqNr, info)
 			require.NoError(t, err)
 			res, err := L1InfoDepositTxData(depTx.Data)
 			require.NoError(t, err, "expected valid deposit info")
@@ -53,6 +61,7 @@ func TestParseL1InfoDepositTxData(t *testing.T) {
 			assert.True(t, res.BaseFee.Sign() >= 0)
 			assert.Equal(t, res.BaseFee.Bytes(), info.BaseFee().Bytes())
 			assert.Equal(t, res.BlockHash, info.Hash())
+			assert.Equal(t, res.SequenceNumber, seqNr)
 		})
 	}
 	t.Run("no data", func(t *testing.T) {

op-node/rollup/derive/pipeline.go

@@ -11,7 +11,7 @@ import (
 )
 
 type L1Fetcher interface {
-	L1HeadBlockRef(ctx context.Context) (eth.L1BlockRef, error)
+	L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error)
 	L1BlockRefByNumberFetcher
 	L1BlockRefByHashFetcher
 	L1ReceiptsFetcher

op-node/rollup/driver/driver.go

@@ -5,8 +5,6 @@ import (
 	"math/big"
 
 	"github.com/ethereum-optimism/optimism/op-node/eth"
-	"github.com/ethereum-optimism/optimism/op-node/l1"
-	"github.com/ethereum-optimism/optimism/op-node/l2"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
 	"github.com/ethereum/go-ethereum/common"
@@ -36,13 +34,13 @@ type Metrics interface {
 }
 
 type Downloader interface {
-	InfoByHash(ctx context.Context, hash common.Hash) (eth.L1Info, error)
-	Fetch(ctx context.Context, blockHash common.Hash) (eth.L1Info, types.Transactions, eth.ReceiptsFetcher, error)
+	InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error)
+	Fetch(ctx context.Context, blockHash common.Hash) (eth.BlockInfo, types.Transactions, eth.ReceiptsFetcher, error)
 }
 
 type L1Chain interface {
 	derive.L1Fetcher
-	L1HeadBlockRef(context.Context) (eth.L1BlockRef, error)
+	L1BlockRefByLabel(context.Context, eth.BlockLabel) (eth.L1BlockRef, error)
 }
 
 type L2Chain interface {
@@ -73,7 +71,7 @@ type Network interface {
 	PublishL2Payload(ctx context.Context, payload *eth.ExecutionPayload) error
 }
 
-func NewDriver(driverCfg *Config, cfg *rollup.Config, l2 *l2.Source, l1 *l1.Source, network Network, log log.Logger, snapshotLog log.Logger, metrics Metrics) *Driver {
+func NewDriver(driverCfg *Config, cfg *rollup.Config, l2 L2Chain, l1 L1Chain, network Network, log log.Logger, snapshotLog log.Logger, metrics Metrics) *Driver {
 	output := &outputImpl{
 		Config: cfg,
 		dl:     l1,

op-node/rollup/driver/state.go

@@ -109,7 +109,7 @@ func NewState(driverCfg *Config, log log.Logger, snapshotLog log.Logger, config
 // Start starts up the state loop. The context is only for initialization.
 // The loop will have been started iff err is not nil.
 func (s *state) Start(ctx context.Context) error {
-	l1Head, err := s.l1.L1HeadBlockRef(ctx)
+	l1Head, err := s.l1.L1BlockRefByLabel(ctx, eth.Unsafe)
 	if err != nil {
 		return err
 	}

op-node/rollup/output_root.go

+package rollup
+
+import (
+	"bytes"
+
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func ComputeL2OutputRoot(l2OutputRootVersion eth.Bytes32, blockHash common.Hash, blockRoot common.Hash, storageRoot common.Hash) eth.Bytes32 {
+	var buf bytes.Buffer
+	buf.Write(l2OutputRootVersion[:])
+	buf.Write(blockRoot.Bytes())
+	buf.Write(storageRoot[:])
+	buf.Write(blockHash.Bytes())
+	return eth.Bytes32(crypto.Keccak256Hash(buf.Bytes()))
+}

op-node/rollup/sync/start.go

@@ -48,7 +48,7 @@ import (
 )
 
 type L1Chain interface {
-	L1HeadBlockRef(ctx context.Context) (eth.L1BlockRef, error)
+	L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error)
 	L1BlockRefByNumber(ctx context.Context, number uint64) (eth.L1BlockRef, error)
 }
 
@@ -66,7 +66,7 @@ const MaxReorgDepth = 500
 //     or canonical in the L1 chain.
 //   - `canonical`: true if the block is canonical in the L1 chain.
 func isAheadOrCanonical(ctx context.Context, l1 L1Chain, block eth.BlockID) (aheadOrCanonical bool, canonical bool, err error) {
-	if l1Head, err := l1.L1HeadBlockRef(ctx); err != nil {
+	if l1Head, err := l1.L1BlockRefByLabel(ctx, eth.Unsafe); err != nil {
 		return false, false, err
 	} else if block.Number > l1Head.Number {
 		return true, false, nil

op-node/l1/batching.go → op-node/sources/batching.go

-package l1
+package sources
 
 import (
 	"context"
@@ -23,7 +23,7 @@ type IterativeBatchCall[K any, V any, O any] struct {
 
 	makeRequest func(K) (V, rpc.BatchElem)
 	makeResults func([]K, []V) (O, error)
-	getBatch    batchCallContextFn
+	getBatch    BatchCallContextFn
 
 	requestsValues []V
 	scheduled      chan rpc.BatchElem
@@ -37,7 +37,7 @@ func NewIterativeBatchCall[K any, V any, O any](
 	requestsKeys []K,
 	makeRequest func(K) (V, rpc.BatchElem),
 	makeResults func([]K, []V) (O, error),
-	getBatch batchCallContextFn,
+	getBatch BatchCallContextFn,
 	batchSize int) *IterativeBatchCall[K, V, O] {
 
 	if len(requestsKeys) < batchSize {

op-node/l1/batching_test.go → op-node/sources/batching_test.go

-package l1
+package sources
 
 import (
 	"context"

op-node/l1/source_test.go → op-node/sources/eth_client_test.go

-package l1
+package sources
 
 import (
 	"context"
@@ -7,25 +7,19 @@ import (
 	"testing"
 
 	"github.com/ethereum-optimism/optimism/op-node/client"
-	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/rpc"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 )
 
 type mockRPC struct {
 	mock.Mock
 }
 
-// we catch the optimized version, instead of mocking a lot of split/parallel calls
-func (m *mockRPC) batchCall(ctx context.Context, b []rpc.BatchElem) error {
-	return m.MethodCalled("batchCall", ctx, b).Get(0).([]error)[0]
-}
-
 func (m *mockRPC) BatchCallContext(ctx context.Context, b []rpc.BatchElem) error {
 	return m.MethodCalled("BatchCallContext", ctx, b).Get(0).([]error)[0]
 }
@@ -45,152 +39,82 @@ func (m *mockRPC) Close() {
 
 var _ client.RPC = (*mockRPC)(nil)
 
+var testEthClientConfig = &EthClientConfig{
+	ReceiptsCacheSize:     10,
+	TransactionsCacheSize: 10,
+	HeadersCacheSize:      10,
+	MaxRequestsPerBatch:   20,
+	MaxConcurrentRequests: 10,
+	TrustRPC:              false,
+}
+
 func randHash() (out common.Hash) {
 	rand.Read(out[:])
 	return out
 }
 
-func randHeader() *types.Header {
-	return &types.Header{
+func randHeader() (*types.Header, *rpcHeader) {
+	hdr := &types.Header{
 		ParentHash:  randHash(),
 		UncleHash:   randHash(),
 		Coinbase:    common.Address{},
 		Root:        randHash(),
 		TxHash:      randHash(),
 		ReceiptHash: randHash(),
+		Bloom:       types.Bloom{},
+		Difficulty:  big.NewInt(42),
 		Number:      big.NewInt(1234),
+		GasLimit:    0,
+		GasUsed:     0,
 		Time:        123456,
+		Extra:       make([]byte, 0),
 		MixDigest:   randHash(),
+		Nonce:       types.BlockNonce{},
 		BaseFee:     big.NewInt(100),
 	}
-}
-
-func randTransaction(i uint64) *types.Transaction {
-	return types.NewTx(&types.DynamicFeeTx{
-		ChainID:   big.NewInt(999),
-		Nonce:     i,
-		GasTipCap: big.NewInt(1),
-		GasFeeCap: big.NewInt(100),
-		Gas:       21000,
-		To:        &common.Address{0x42},
-		Value:     big.NewInt(0),
-	})
-}
-
-func randTxs(offset uint64, count uint64) types.Transactions {
-	out := make(types.Transactions, count)
-	for i := uint64(0); i < count; i++ {
-		out[i] = randTransaction(offset + i)
-	}
-	return out
-}
-
-func TestSource_InfoByHash(t *testing.T) {
-	m := new(mockRPC)
-	hdr := randHeader()
 	rhdr := &rpcHeader{
 		cache:  rpcHeaderCacheInfo{Hash: hdr.Hash()},
 		header: *hdr,
 	}
+	return hdr, rhdr
+}
+
+func TestEthClient_InfoByHash(t *testing.T) {
+	m := new(mockRPC)
+	_, rhdr := randHeader()
 	expectedInfo, _ := rhdr.Info(true)
-	h := rhdr.header.Hash()
 	ctx := context.Background()
-	m.On("CallContext", ctx, new(*rpcHeader), "eth_getBlockByHash", []interface{}{h, false}).Run(func(args mock.Arguments) {
+	m.On("CallContext", ctx, new(*rpcHeader),
+		"eth_getBlockByHash", []interface{}{rhdr.cache.Hash, false}).Run(func(args mock.Arguments) {
 		*args[1].(**rpcHeader) = rhdr
 	}).Return([]error{nil})
-	s, err := NewSource(m, nil, DefaultConfig(&rollup.Config{SeqWindowSize: 10}, true))
-	assert.NoError(t, err)
-	info, err := s.InfoByHash(ctx, h)
-	assert.NoError(t, err)
-	assert.Equal(t, info, expectedInfo)
+	s, err := NewEthClient(m, nil, nil, testEthClientConfig)
+	require.NoError(t, err)
+	info, err := s.InfoByHash(ctx, rhdr.cache.Hash)
+	require.NoError(t, err)
+	require.Equal(t, info, expectedInfo)
 	m.Mock.AssertExpectations(t)
 	// Again, without expecting any calls from the mock, the cache will return the block
-	info, err = s.InfoByHash(ctx, h)
-	assert.NoError(t, err)
-	assert.Equal(t, info, expectedInfo)
+	info, err = s.InfoByHash(ctx, rhdr.cache.Hash)
+	require.NoError(t, err)
+	require.Equal(t, info, expectedInfo)
 	m.Mock.AssertExpectations(t)
 }
 
-func TestSource_InfoByNumber(t *testing.T) {
+func TestEthClient_InfoByNumber(t *testing.T) {
 	m := new(mockRPC)
-	hdr := randHeader()
-	rhdr := &rpcHeader{
-		cache:  rpcHeaderCacheInfo{Hash: hdr.Hash()},
-		header: *hdr,
-	}
+	_, rhdr := randHeader()
 	expectedInfo, _ := rhdr.Info(true)
-	n := hdr.Number.Uint64()
+	n := rhdr.header.Number
 	ctx := context.Background()
-	m.On("CallContext", ctx, new(*rpcHeader), "eth_getBlockByNumber", []interface{}{hexutil.EncodeUint64(n), false}).Run(func(args mock.Arguments) {
+	m.On("CallContext", ctx, new(*rpcHeader),
+		"eth_getBlockByNumber", []interface{}{hexutil.EncodeBig(n), false}).Run(func(args mock.Arguments) {
 		*args[1].(**rpcHeader) = rhdr
 	}).Return([]error{nil})
-	s, err := NewSource(m, nil, DefaultConfig(&rollup.Config{SeqWindowSize: 10}, true))
-	assert.NoError(t, err)
-	info, err := s.InfoByNumber(ctx, n)
-	assert.NoError(t, err)
-	assert.Equal(t, info, expectedInfo)
-	m.Mock.AssertExpectations(t)
-}
-
-func TestSource_FetchAllTransactions(t *testing.T) {
-	m := new(mockRPC)
-
-	ctx := context.Background()
-	a, b := randHeader(), randHeader()
-	blocks := []*rpcBlock{
-		{
-			header: rpcHeader{
-				cache: rpcHeaderCacheInfo{
-					Hash: a.Hash(),
-				},
-				header: *a,
-			},
-			extra: rpcBlockCacheInfo{
-				Transactions: randTxs(0, 4),
-			},
-		},
-		{
-			header: rpcHeader{
-				cache: rpcHeaderCacheInfo{
-					Hash: b.Hash(),
-				},
-				header: *b,
-			},
-			extra: rpcBlockCacheInfo{
-				Transactions: randTxs(4, 3),
-			},
-		},
-	}
-	expectedRequest := make([]rpc.BatchElem, len(blocks))
-	expectedTxLists := make([]types.Transactions, len(blocks))
-	for i, b := range blocks {
-		expectedRequest[i] = rpc.BatchElem{Method: "eth_getBlockByHash", Args: []interface{}{b.header.header.Hash(), true}, Result: new(rpcBlock)}
-		expectedTxLists[i] = b.extra.Transactions
-	}
-
-	m.On("batchCall", ctx, expectedRequest).Run(func(args mock.Arguments) {
-		batch := args[1].([]rpc.BatchElem)
-		for i, b := range blocks {
-			*batch[i].Result.(*rpcBlock) = *b
-		}
-	}).Return([]error{nil})
-
-	s, err := NewSource(m, nil, DefaultConfig(&rollup.Config{SeqWindowSize: 10}, true))
-	assert.NoError(t, err)
-	s.batchCall = m.batchCall // override the optimized batch call
-
-	id := func(i int) eth.BlockID {
-		return eth.BlockID{Hash: blocks[i].header.header.Hash(), Number: blocks[i].header.header.Number.Uint64()}
-	}
-
-	txLists, err := s.FetchAllTransactions(ctx, []eth.BlockID{id(0), id(1)})
-	assert.NoError(t, err)
-	assert.Equal(t, txLists, expectedTxLists)
-	m.Mock.AssertExpectations(t)
-
-	// again, but now without expecting any calls (transactions were cached)
-	txLists, err = s.FetchAllTransactions(ctx, []eth.BlockID{id(0), id(1)})
-	assert.NoError(t, err)
-	assert.Equal(t, txLists, expectedTxLists)
+	s, err := NewL1Client(m, nil, nil, L1ClientDefaultConfig(&rollup.Config{SeqWindowSize: 10}, true))
+	require.NoError(t, err)
+	info, err := s.InfoByNumber(ctx, n.Uint64())
+	require.NoError(t, err)
+	require.Equal(t, info, expectedInfo)
 	m.Mock.AssertExpectations(t)
 }

op-node/sources/l1_client.go

+package sources
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/ethereum-optimism/optimism/op-node/client"
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/rollup"
+	"github.com/ethereum-optimism/optimism/op-node/sources/caching"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+type L1ClientConfig struct {
+	EthClientConfig
+
+	L1BlockRefsCacheSize int
+}
+
+func L1ClientDefaultConfig(config *rollup.Config, trustRPC bool) *L1ClientConfig {
+	// Cache 3/2 worth of sequencing window of receipts and txs
+	span := int(config.SeqWindowSize) * 3 / 2
+	if span > 1000 { // sanity cap. If a large sequencing window is configured, do not make the cache too large
+		span = 1000
+	}
+	return &L1ClientConfig{
+		EthClientConfig: EthClientConfig{
+			// receipts and transactions are cached per block
+			ReceiptsCacheSize:     span,
+			TransactionsCacheSize: span,
+			HeadersCacheSize:      span,
+			MaxRequestsPerBatch:   20, // TODO: tune batch param
+			MaxConcurrentRequests: 10,
+			TrustRPC:              trustRPC,
+		},
+		L1BlockRefsCacheSize: span,
+	}
+}
+
+// L1Client provides typed bindings to retrieve L1 data from an RPC source,
+// with optimized batch requests, cached results, and flag to not trust the RPC
+// (i.e. to verify all returned contents against corresponding block hashes).
+type L1Client struct {
+	*EthClient
+
+	// cache L1BlockRef by hash
+	// common.Hash -> eth.L1BlockRef
+	l1BlockRefsCache *caching.LRUCache
+}
+
+// NewL1Client wraps a RPC with bindings to fetch L1 data, while logging errors, tracking metrics (optional), and caching.
+func NewL1Client(client client.RPC, log log.Logger, metrics caching.Metrics, config *L1ClientConfig) (*L1Client, error) {
+	ethClient, err := NewEthClient(client, log, metrics, &config.EthClientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return &L1Client{
+		EthClient:        ethClient,
+		l1BlockRefsCache: caching.NewLRUCache(metrics, "blockrefs", config.L1BlockRefsCacheSize),
+	}, nil
+}
+
+func (s *L1Client) L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error) {
+	info, err := s.InfoByLabel(ctx, label)
+	if err != nil {
+		return eth.L1BlockRef{}, fmt.Errorf("failed to fetch head header: %w", err)
+	}
+	ref := eth.InfoToL1BlockRef(info)
+	s.l1BlockRefsCache.Add(ref.Hash, ref)
+	return ref, nil
+}
+
+func (s *L1Client) L1BlockRefByNumber(ctx context.Context, num uint64) (eth.L1BlockRef, error) {
+	info, err := s.InfoByNumber(ctx, num)
+	if err != nil {
+		return eth.L1BlockRef{}, fmt.Errorf("failed to fetch header by num %d: %w", num, err)
+	}
+	ref := eth.InfoToL1BlockRef(info)
+	s.l1BlockRefsCache.Add(ref.Hash, ref)
+	return ref, nil
+}
+
+func (s *L1Client) L1BlockRefByHash(ctx context.Context, hash common.Hash) (eth.L1BlockRef, error) {
+	if v, ok := s.l1BlockRefsCache.Get(hash); ok {
+		return v.(eth.L1BlockRef), nil
+	}
+	info, err := s.InfoByHash(ctx, hash)
+	if err != nil {
+		return eth.L1BlockRef{}, fmt.Errorf("failed to fetch header by hash %v: %w", hash, err)
+	}
+	ref := eth.InfoToL1BlockRef(info)
+	s.l1BlockRefsCache.Add(ref.Hash, ref)
+	return ref, nil
+}

op-node/l1/request_sema.go → op-node/sources/limit.go

-package l1
+package sources
 
 import (
 	"context"

op-node/l1/receipts.go → op-node/sources/receipts.go

-package l1
+package sources
 
 import (
 	"fmt"
@@ -82,7 +82,7 @@ func makeReceiptRequest(txHash common.Hash) (*types.Receipt, rpc.BatchElem) {
 }
 
 // NewReceiptsFetcher creates a receipt fetcher that can iteratively fetch the receipts matching the given txs.
-func NewReceiptsFetcher(block eth.BlockID, receiptHash common.Hash, txHashes []common.Hash, getBatch batchCallContextFn, batchSize int) eth.ReceiptsFetcher {
+func NewReceiptsFetcher(block eth.BlockID, receiptHash common.Hash, txHashes []common.Hash, getBatch BatchCallContextFn, batchSize int) eth.ReceiptsFetcher {
 	return NewIterativeBatchCall[common.Hash, *types.Receipt, types.Receipts](
 		txHashes,
 		makeReceiptRequest,

op-node/l1/types.go → op-node/sources/types.go

-package l1
+package sources
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"math/big"
@@ -8,10 +9,13 @@ import (
 	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/ethereum/go-ethereum/trie"
 )
 
-// Note: we do this ugly typing because we want the best, and the standard bindings are not sufficient:
+type BatchCallContextFn func(ctx context.Context, b []rpc.BatchElem) error
+
+// Note: these types are used, instead of the geth types, to enable:
 // - batched calls of many block requests (standard bindings do extra uncle-header fetches, cannot be batched nicely)
 // - ignore uncle data (does not even exist anymore post-Merge)
 // - use cached block hash, if we trust the RPC.
@@ -22,9 +26,12 @@ import (
 //
 // This way we minimize RPC calls, enable batching, and can choose to verify what the RPC gives us.
 
+// HeaderInfo contains all the header-info required to implement the eth.BlockInfo interface,
+// used in the rollup state-transition, with pre-computed block hash.
 type HeaderInfo struct {
 	hash        common.Hash
 	parentHash  common.Hash
+	coinbase    common.Address
 	root        common.Hash
 	number      uint64
 	time        uint64
@@ -34,7 +41,7 @@ type HeaderInfo struct {
 	receiptHash common.Hash
 }
 
-var _ eth.L1Info = (*HeaderInfo)(nil)
+var _ eth.BlockInfo = (*HeaderInfo)(nil)
 
 func (info *HeaderInfo) Hash() common.Hash {
 	return info.hash
@@ -44,6 +51,10 @@ func (info *HeaderInfo) ParentHash() common.Hash {
 	return info.parentHash
 }
 
+func (info *HeaderInfo) Coinbase() common.Address {
+	return info.coinbase
+}
+
 func (info *HeaderInfo) Root() common.Hash {
 	return info.root
 }
@@ -68,15 +79,6 @@ func (info *HeaderInfo) ID() eth.BlockID {
 	return eth.BlockID{Hash: info.hash, Number: info.number}
 }
 
-func (info *HeaderInfo) BlockRef() eth.L1BlockRef {
-	return eth.L1BlockRef{
-		Hash:       info.hash,
-		Number:     info.number,
-		ParentHash: info.parentHash,
-		Time:       info.time,
-	}
-}
-
 func (info *HeaderInfo) ReceiptHash() common.Hash {
 	return info.receiptHash
 }

op-node/testutils/fake_chain.go

@@ -3,6 +3,7 @@ package testutils
 import (
 	"context"
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum"
@@ -132,7 +133,10 @@ func (m *FakeChainSource) L1BlockRefByHash(ctx context.Context, l1Hash common.Ha
 	return eth.L1BlockRef{}, ethereum.NotFound
 }
 
-func (m *FakeChainSource) L1HeadBlockRef(ctx context.Context) (eth.L1BlockRef, error) {
+func (m *FakeChainSource) L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error) {
+	if label != eth.Unsafe {
+		return eth.L1BlockRef{}, fmt.Errorf("testutil FakeChainSource does not support L1BlockRefByLabel(%s)", label)
+	}
 	m.log.Trace("L1HeadBlockRef", "l1Head", m.l1head, "reorg", m.l1reorg)
 	l := len(m.l1s[m.l1reorg])
 	if l == 0 {

op-node/testutils/l1info.go

@@ -9,57 +9,61 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
-type MockL1Info struct {
+type MockBlockInfo struct {
 	// Prefixed all fields with "Info" to avoid collisions with the interface method names.
 
-	InfoHash           common.Hash
-	InfoParentHash     common.Hash
-	InfoRoot           common.Hash
-	InfoNum            uint64
-	InfoTime           uint64
-	InfoMixDigest      [32]byte
-	InfoBaseFee        *big.Int
-	InfoReceiptRoot    common.Hash
-	InfoSequenceNumber uint64
+	InfoHash        common.Hash
+	InfoParentHash  common.Hash
+	InfoCoinbase    common.Address
+	InfoRoot        common.Hash
+	InfoNum         uint64
+	InfoTime        uint64
+	InfoMixDigest   [32]byte
+	InfoBaseFee     *big.Int
+	InfoReceiptRoot common.Hash
 }
 
-func (l *MockL1Info) Hash() common.Hash {
+func (l *MockBlockInfo) Hash() common.Hash {
 	return l.InfoHash
 }
 
-func (l *MockL1Info) ParentHash() common.Hash {
+func (l *MockBlockInfo) ParentHash() common.Hash {
 	return l.InfoParentHash
 }
 
-func (l *MockL1Info) Root() common.Hash {
+func (l *MockBlockInfo) Coinbase() common.Address {
+	return l.InfoCoinbase
+}
+
+func (l *MockBlockInfo) Root() common.Hash {
 	return l.InfoRoot
 }
 
-func (l *MockL1Info) NumberU64() uint64 {
+func (l *MockBlockInfo) NumberU64() uint64 {
 	return l.InfoNum
 }
 
-func (l *MockL1Info) Time() uint64 {
+func (l *MockBlockInfo) Time() uint64 {
 	return l.InfoTime
 }
 
-func (l *MockL1Info) MixDigest() common.Hash {
+func (l *MockBlockInfo) MixDigest() common.Hash {
 	return l.InfoMixDigest
 }
 
-func (l *MockL1Info) BaseFee() *big.Int {
+func (l *MockBlockInfo) BaseFee() *big.Int {
 	return l.InfoBaseFee
 }
 
-func (l *MockL1Info) ReceiptHash() common.Hash {
+func (l *MockBlockInfo) ReceiptHash() common.Hash {
 	return l.InfoReceiptRoot
 }
 
-func (l *MockL1Info) ID() eth.BlockID {
+func (l *MockBlockInfo) ID() eth.BlockID {
 	return eth.BlockID{Hash: l.InfoHash, Number: l.InfoNum}
 }
 
-func (l *MockL1Info) BlockRef() eth.L1BlockRef {
+func (l *MockBlockInfo) BlockRef() eth.L1BlockRef {
 	return eth.L1BlockRef{
 		Hash:       l.InfoHash,
 		Number:     l.InfoNum,
@@ -68,26 +72,21 @@ func (l *MockL1Info) BlockRef() eth.L1BlockRef {
 	}
 }
 
-func (l *MockL1Info) SequenceNumber() uint64 {
-	return l.InfoSequenceNumber
-}
-
-func RandomL1Info(rng *rand.Rand) *MockL1Info {
-	return &MockL1Info{
-		InfoParentHash:     RandomHash(rng),
-		InfoNum:            rng.Uint64(),
-		InfoTime:           rng.Uint64(),
-		InfoHash:           RandomHash(rng),
-		InfoBaseFee:        big.NewInt(rng.Int63n(1000_000 * 1e9)), // a million GWEI
-		InfoReceiptRoot:    types.EmptyRootHash,
-		InfoRoot:           RandomHash(rng),
-		InfoSequenceNumber: rng.Uint64(),
+func RandomBlockInfo(rng *rand.Rand) *MockBlockInfo {
+	return &MockBlockInfo{
+		InfoParentHash:  RandomHash(rng),
+		InfoNum:         rng.Uint64(),
+		InfoTime:        rng.Uint64(),
+		InfoHash:        RandomHash(rng),
+		InfoBaseFee:     big.NewInt(rng.Int63n(1000_000 * 1e9)), // a million GWEI
+		InfoReceiptRoot: types.EmptyRootHash,
+		InfoRoot:        RandomHash(rng),
 	}
 }
 
-func MakeL1Info(fn func(l *MockL1Info)) func(rng *rand.Rand) *MockL1Info {
-	return func(rng *rand.Rand) *MockL1Info {
-		l := RandomL1Info(rng)
+func MakeBlockInfo(fn func(l *MockBlockInfo)) func(rng *rand.Rand) *MockBlockInfo {
+	return func(rng *rand.Rand) *MockBlockInfo {
+		l := RandomBlockInfo(rng)
 		if fn != nil {
 			fn(l)
 		}

op-node/testutils/mock_eth_client.go

+package testutils
+
+import (
+	"context"
+
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/stretchr/testify/mock"
+)
+
+type MockEthClient struct {
+	mock.Mock
+}
+
+func (m *MockEthClient) InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error) {
+	out := m.Mock.MethodCalled("InfoByHash", hash)
+	return *out[0].(*eth.BlockInfo), *out[1].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoByHash(hash common.Hash, info eth.BlockInfo, err error) {
+	m.Mock.On("InfoByHash", hash).Once().Return(&info, &err)
+}
+
+func (m *MockEthClient) InfoByNumber(ctx context.Context, number uint64) (eth.BlockInfo, error) {
+	out := m.Mock.MethodCalled("InfoByNumber", number)
+	return *out[0].(*eth.BlockInfo), *out[1].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoByNumber(number uint64, info eth.BlockInfo, err error) {
+	m.Mock.On("InfoByNumber", number).Once().Return(&info, &err)
+}
+
+func (m *MockEthClient) InfoByLabel(ctx context.Context, label eth.BlockLabel) (eth.BlockInfo, error) {
+	out := m.Mock.MethodCalled("InfoByLabel", label)
+	return *out[0].(*eth.BlockInfo), *out[1].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoByLabel(label eth.BlockLabel, info eth.BlockInfo, err error) {
+	m.Mock.On("InfoByLabel", label).Once().Return(&info, &err)
+}
+
+func (m *MockEthClient) InfoByRpcNumber(ctx context.Context, num rpc.BlockNumber) (eth.BlockInfo, error) {
+	out := m.Mock.MethodCalled("InfoByRpcNumber", num)
+	return *out[0].(*eth.BlockInfo), *out[1].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoByRpcNumber(num rpc.BlockNumber, info eth.BlockInfo, err error) {
+	m.Mock.On("InfoByRpcNumber", num).Once().Return(&info, &err)
+}
+
+func (m *MockEthClient) InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, types.Transactions, error) {
+	out := m.Mock.MethodCalled("InfoAndTxsByHash", hash)
+	return out[0].(eth.BlockInfo), out[1].(types.Transactions), *out[2].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoAndTxsByHash(hash common.Hash, info eth.BlockInfo, transactions types.Transactions, err error) {
+	m.Mock.On("InfoAndTxsByHash", hash).Once().Return(info, transactions, &err)
+}
+
+func (m *MockEthClient) InfoAndTxsByNumber(ctx context.Context, number uint64) (eth.BlockInfo, types.Transactions, error) {
+	out := m.Mock.MethodCalled("InfoAndTxsByNumber", number)
+	return out[0].(eth.BlockInfo), out[1].(types.Transactions), *out[2].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoAndTxsByNumber(number uint64, info eth.BlockInfo, transactions types.Transactions, err error) {
+	m.Mock.On("InfoAndTxsByNumber", number).Once().Return(info, transactions, &err)
+}
+
+func (m *MockEthClient) InfoAndTxsByLabel(ctx context.Context, label eth.BlockLabel) (eth.BlockInfo, types.Transactions, error) {
+	out := m.Mock.MethodCalled("InfoAndTxsByLabel", label)
+	return out[0].(eth.BlockInfo), out[1].(types.Transactions), *out[2].(*error)
+}
+
+func (m *MockEthClient) ExpectInfoAndTxsByLabel(label eth.BlockLabel, info eth.BlockInfo, transactions types.Transactions, err error) {
+	m.Mock.On("InfoAndTxsByLabel", label).Once().Return(info, transactions, &err)
+}
+
+func (m *MockEthClient) Fetch(ctx context.Context, blockHash common.Hash) (eth.BlockInfo, types.Transactions, eth.ReceiptsFetcher, error) {
+	out := m.Mock.MethodCalled("Fetch", blockHash)
+	return *out[0].(*eth.BlockInfo), out[1].(types.Transactions), out[2].(eth.ReceiptsFetcher), *out[3].(*error)
+}
+
+func (m *MockEthClient) ExpectFetch(hash common.Hash, info eth.BlockInfo, transactions types.Transactions, receipts types.Receipts, err error) {
+	m.Mock.On("Fetch", hash).Once().Return(&info, transactions, eth.FetchedReceipts(receipts), &err)
+}
+
+func (m *MockEthClient) GetProof(ctx context.Context, address common.Address, blockTag string) (*eth.AccountResult, error) {
+	return m.Mock.MethodCalled("GetProof", address, blockTag).Get(0).(*eth.AccountResult), nil
+}
+
+func (m *MockEthClient) ExpectGetProof(address common.Address, blockTag string, result *eth.AccountResult, err error) {
+	m.Mock.On("GetProof", address, blockTag).Once().Return(result, &err)
+}

op-node/testutils/mock_l1.go

@@ -5,35 +5,28 @@ import (
 
 	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/stretchr/testify/mock"
 )
 
 type MockL1Source struct {
-	mock.Mock
+	MockEthClient
 }
 
-func (m *MockL1Source) InfoByHash(ctx context.Context, hash common.Hash) (eth.L1Info, error) {
-	out := m.Mock.MethodCalled("InfoByHash", hash)
-	return *out[0].(*eth.L1Info), *out[1].(*error)
-}
-
-func (m *MockL1Source) ExpectInfoByHash(hash common.Hash, info eth.L1Info, err error) {
-	m.Mock.On("InfoByHash", hash).Once().Return(&info, &err)
+func (m *MockL1Source) L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error) {
+	out := m.Mock.MethodCalled("L1BlockRefByLabel")
+	return out[0].(eth.L1BlockRef), *out[1].(*error)
 }
 
-func (m *MockL1Source) L1HeadBlockRef(ctx context.Context) (eth.L1BlockRef, error) {
-	out := m.Mock.MethodCalled("L1HeadBlockRef")
-	return out[0].(eth.L1BlockRef), *out[1].(*error)
+func (m *MockL1Source) ExpectL1BlockRefByLabel(label eth.BlockLabel, ref eth.L1BlockRef, err error) {
+	m.Mock.On("L1BlockRefByLabel", label).Once().Return(ref, &err)
 }
 
-func (m *MockL1Source) L1BlockRefByNumber(ctx context.Context, u uint64) (eth.L1BlockRef, error) {
-	out := m.Mock.MethodCalled("L1BlockRefByNumber", u)
+func (m *MockL1Source) L1BlockRefByNumber(ctx context.Context, num uint64) (eth.L1BlockRef, error) {
+	out := m.Mock.MethodCalled("L1BlockRefByNumber", num)
 	return out[0].(eth.L1BlockRef), *out[1].(*error)
 }
 
-func (m *MockL1Source) ExpectL1BlockRefByNumber(u uint64, ref eth.L1BlockRef, err error) {
-	m.Mock.On("L1BlockRefByNumber", u).Once().Return(ref, &err)
+func (m *MockL1Source) ExpectL1BlockRefByNumber(num uint64, ref eth.L1BlockRef, err error) {
+	m.Mock.On("L1BlockRefByNumber", num).Once().Return(ref, &err)
 }
 
 func (m *MockL1Source) L1BlockRefByHash(ctx context.Context, hash common.Hash) (eth.L1BlockRef, error) {
@@ -44,21 +37,3 @@ func (m *MockL1Source) L1BlockRefByHash(ctx context.Context, hash common.Hash) (
 func (m *MockL1Source) ExpectL1BlockRefByHash(hash common.Hash, ref eth.L1BlockRef, err error) {
 	m.Mock.On("L1BlockRefByHash", hash).Once().Return(ref, &err)
 }
-
-func (m *MockL1Source) Fetch(ctx context.Context, blockHash common.Hash) (eth.L1Info, types.Transactions, eth.ReceiptsFetcher, error) {
-	out := m.Mock.MethodCalled("Fetch", blockHash)
-	return *out[0].(*eth.L1Info), out[1].(types.Transactions), out[2].(eth.ReceiptsFetcher), *out[3].(*error)
-}
-
-func (m *MockL1Source) ExpectFetch(hash common.Hash, info eth.L1Info, transactions types.Transactions, receipts types.Receipts, err error) {
-	m.Mock.On("Fetch", hash).Once().Return(&info, transactions, eth.FetchedReceipts(receipts), &err)
-}
-
-func (m *MockL1Source) InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.L1Info, types.Transactions, error) {
-	out := m.Mock.MethodCalled("InfoAndTxsByHash", hash)
-	return out[0].(eth.L1Info), out[1].(types.Transactions), *out[2].(*error)
-}
-
-func (m *MockL1Source) ExpectInfoAndTxsByHash(hash common.Hash, info eth.L1Info, transactions types.Transactions, err error) {
-	m.Mock.On("InfoAndTxsByHash", hash).Once().Return(info, transactions, &err)
-}