op-program: Implement oracle based L1 fetcher

op-program/client/l1/client.go

@@ -0,0 +1,69 @@
+package l1
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+var (
+	ErrNotFound     = ethereum.NotFound
+	ErrUnknownLabel = errors.New("unknown label")
+)
+
+type OracleL1Client struct {
+	oracle Oracle
+	head   eth.L1BlockRef
+}
+
+func NewOracleL1Client(logger log.Logger, oracle Oracle, l1Head common.Hash) *OracleL1Client {
+	head := eth.InfoToL1BlockRef(oracle.HeaderByBlockHash(l1Head))
+	logger.Info("L1 head loaded", "hash", head.Hash, "number", head.Number)
+	return &OracleL1Client{
+		oracle: oracle,
+		head:   head,
+	}
+}
+
+func (o OracleL1Client) L1BlockRefByLabel(ctx context.Context, label eth.BlockLabel) (eth.L1BlockRef, error) {
+	if label != eth.Unsafe && label != eth.Safe && label != eth.Finalized {
+		return eth.L1BlockRef{}, fmt.Errorf("%w: %s", ErrUnknownLabel, label)
+	}
+	// The L1 head is pre-agreed and unchanging so it can be used for all of unsafe, safe and finalized
+	return o.head, nil
+}
+
+func (o OracleL1Client) L1BlockRefByNumber(ctx context.Context, number uint64) (eth.L1BlockRef, error) {
+	if number > o.head.Number {
+		return eth.L1BlockRef{}, fmt.Errorf("%w: block number %d", ErrNotFound, number)
+	}
+	block := o.head
+	for block.Number > number {
+		block = eth.InfoToL1BlockRef(o.oracle.HeaderByBlockHash(block.ParentHash))
+	}
+	return block, nil
+}
+
+func (o OracleL1Client) L1BlockRefByHash(ctx context.Context, hash common.Hash) (eth.L1BlockRef, error) {
+	return eth.InfoToL1BlockRef(o.oracle.HeaderByBlockHash(hash)), nil
+}
+
+func (o OracleL1Client) InfoByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, error) {
+	return o.oracle.HeaderByBlockHash(hash), nil
+}
+
+func (o OracleL1Client) FetchReceipts(ctx context.Context, blockHash common.Hash) (eth.BlockInfo, types.Receipts, error) {
+	info, rcpts := o.oracle.ReceiptsByBlockHash(blockHash)
+	return info, rcpts, nil
+}
+
+func (o OracleL1Client) InfoAndTxsByHash(ctx context.Context, hash common.Hash) (eth.BlockInfo, types.Transactions, error) {
+	info, txs := o.oracle.TransactionsByBlockHash(hash)
+	return info, txs, nil
+}

op-program/client/l1/client_test.go

@@ -0,0 +1,210 @@
+package l1
+
+import (
+	"context"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
+	"github.com/ethereum-optimism/optimism/op-node/sources"
+	"github.com/ethereum-optimism/optimism/op-node/testlog"
+	"github.com/ethereum-optimism/optimism/op-node/testutils"
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/stretchr/testify/require"
+)
+
+var _ derive.L1Fetcher = (*OracleL1Client)(nil)
+
+var head = blockNum(1000)
+
+func TestInfoByHash(t *testing.T) {
+	client, oracle := newClient(t)
+	hash := common.HexToHash("0xAABBCC")
+	expected := &sources.HeaderInfo{}
+	oracle.blocks[hash] = expected
+
+	info, err := client.InfoByHash(context.Background(), hash)
+	require.NoError(t, err)
+	require.Equal(t, expected, info)
+}
+
+func TestL1BlockRefByHash(t *testing.T) {
+	client, oracle := newClient(t)
+	hash := common.HexToHash("0xAABBCC")
+	header := &sources.HeaderInfo{}
+	oracle.blocks[hash] = header
+	expected := eth.InfoToL1BlockRef(header)
+
+	ref, err := client.L1BlockRefByHash(context.Background(), hash)
+	require.NoError(t, err)
+	require.Equal(t, expected, ref)
+}
+
+func TestFetchReceipts(t *testing.T) {
+	client, oracle := newClient(t)
+	hash := common.HexToHash("0xAABBCC")
+	expectedInfo := &sources.HeaderInfo{}
+	expectedReceipts := types.Receipts{
+		&types.Receipt{},
+	}
+	oracle.blocks[hash] = expectedInfo
+	oracle.rcpts[hash] = expectedReceipts
+
+	info, rcpts, err := client.FetchReceipts(context.Background(), hash)
+	require.NoError(t, err)
+	require.Equal(t, expectedInfo, info)
+	require.Equal(t, expectedReceipts, rcpts)
+}
+
+func TestInfoAndTxsByHash(t *testing.T) {
+	client, oracle := newClient(t)
+	hash := common.HexToHash("0xAABBCC")
+	expectedInfo := &sources.HeaderInfo{}
+	expectedTxs := types.Transactions{
+		&types.Transaction{},
+	}
+	oracle.blocks[hash] = expectedInfo
+	oracle.txs[hash] = expectedTxs
+
+	info, txs, err := client.InfoAndTxsByHash(context.Background(), hash)
+	require.NoError(t, err)
+	require.Equal(t, expectedInfo, info)
+	require.Equal(t, expectedTxs, txs)
+}
+
+func TestL1BlockRefByLabel(t *testing.T) {
+	t.Run("Unsafe", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByLabel(context.Background(), eth.Unsafe)
+		require.NoError(t, err)
+		require.Equal(t, eth.InfoToL1BlockRef(head), ref)
+	})
+	t.Run("Safe", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByLabel(context.Background(), eth.Safe)
+		require.NoError(t, err)
+		require.Equal(t, eth.InfoToL1BlockRef(head), ref)
+	})
+	t.Run("Finalized", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByLabel(context.Background(), eth.Finalized)
+		require.NoError(t, err)
+		require.Equal(t, eth.InfoToL1BlockRef(head), ref)
+	})
+	t.Run("UnknownLabel", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByLabel(context.Background(), eth.BlockLabel("unknown"))
+		require.ErrorIs(t, err, ErrUnknownLabel)
+		require.Equal(t, eth.L1BlockRef{}, ref)
+	})
+}
+
+func TestL1BlockRefByNumber(t *testing.T) {
+	t.Run("Head", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByNumber(context.Background(), head.NumberU64())
+		require.NoError(t, err)
+		require.Equal(t, eth.InfoToL1BlockRef(head), ref)
+	})
+	t.Run("AfterHead", func(t *testing.T) {
+		client, _ := newClient(t)
+		ref, err := client.L1BlockRefByNumber(context.Background(), head.NumberU64()+1)
+		// Must be ethereum.NotFound error so the derivation pipeline knows it has gone past the chain head
+		require.ErrorIs(t, err, ethereum.NotFound)
+		require.Equal(t, eth.L1BlockRef{}, ref)
+	})
+	t.Run("ParentOfHead", func(t *testing.T) {
+		client, oracle := newClient(t)
+		parent := blockNum(head.NumberU64() - 1)
+		oracle.blocks[parent.Hash()] = parent
+
+		ref, err := client.L1BlockRefByNumber(context.Background(), parent.NumberU64())
+		require.NoError(t, err)
+		require.Equal(t, eth.InfoToL1BlockRef(parent), ref)
+	})
+	t.Run("AncestorOfHead", func(t *testing.T) {
+		client, oracle := newClient(t)
+		block := head
+		blocks := []eth.BlockInfo{block}
+		for i := 0; i < 10; i++ {
+			block = blockNum(block.NumberU64() - 1)
+			oracle.blocks[block.Hash()] = block
+			blocks = append(blocks, block)
+		}
+
+		for _, block := range blocks {
+			ref, err := client.L1BlockRefByNumber(context.Background(), block.NumberU64())
+			require.NoError(t, err)
+			require.Equal(t, eth.InfoToL1BlockRef(block), ref)
+		}
+	})
+}
+
+func newClient(t *testing.T) (*OracleL1Client, *stubOracle) {
+	stub := &stubOracle{
+		t:      t,
+		blocks: make(map[common.Hash]eth.BlockInfo),
+		txs:    make(map[common.Hash]types.Transactions),
+		rcpts:  make(map[common.Hash]types.Receipts),
+	}
+	stub.blocks[head.Hash()] = head
+	client := NewOracleL1Client(testlog.Logger(t, log.LvlDebug), stub, head.Hash())
+	return client, stub
+}
+
+type stubOracle struct {
+	t *testing.T
+
+	// blocks maps block hash to eth.BlockInfo
+	blocks map[common.Hash]eth.BlockInfo
+
+	// txs maps block hash to transactions
+	txs map[common.Hash]types.Transactions
+
+	// rcpts maps Block hash to receipts
+	rcpts map[common.Hash]types.Receipts
+}
+
+func (o stubOracle) HeaderByBlockHash(blockHash common.Hash) eth.BlockInfo {
+	info, ok := o.blocks[blockHash]
+	if !ok {
+		o.t.Fatalf("unknown block %s", blockHash)
+	}
+	return info
+}
+
+func (o stubOracle) TransactionsByBlockHash(blockHash common.Hash) (eth.BlockInfo, types.Transactions) {
+	txs, ok := o.txs[blockHash]
+	if !ok {
+		o.t.Fatalf("unknown txs %s", blockHash)
+	}
+	return o.HeaderByBlockHash(blockHash), txs
+}
+
+func (o stubOracle) ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockInfo, types.Receipts) {
+	rcpts, ok := o.rcpts[blockHash]
+	if !ok {
+		o.t.Fatalf("unknown rcpts %s", blockHash)
+	}
+	return o.HeaderByBlockHash(blockHash), rcpts
+}
+
+func blockNum(num uint64) eth.BlockInfo {
+	parentNum := num - 1
+	return &testutils.MockBlockInfo{
+		InfoHash:        common.BytesToHash(big.NewInt(int64(num)).Bytes()),
+		InfoParentHash:  common.BytesToHash(big.NewInt(int64(parentNum)).Bytes()),
+		InfoCoinbase:    common.Address{},
+		InfoRoot:        common.Hash{},
+		InfoNum:         num,
+		InfoTime:        num * 2,
+		InfoMixDigest:   [32]byte{},
+		InfoBaseFee:     nil,
+		InfoReceiptRoot: common.Hash{},
+		InfoGasUsed:     0,
+	}
+}

op-program/client/l1/oracle.go

@@ -0,0 +1,18 @@
+package l1
+
+import (
+	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+type Oracle interface {
+	// HeaderByBlockHash retrieves the block header with the given hash.
+	HeaderByBlockHash(blockHash common.Hash) eth.BlockInfo
+
+	// TransactionsByBlockHash retrieves the transactions from the block with the given hash.
+	TransactionsByBlockHash(blockHash common.Hash) (eth.BlockInfo, types.Transactions)
+
+	// ReceiptsByBlockHash retrieves the receipts from the block with the given hash.
+	ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockInfo, types.Receipts)
+}

op-program/client/l2/engine_backend.go

@@ -39,6 +39,7 @@ func NewOracleBackedL2Chain(logger log.Logger, oracle Oracle, chainCfg *params.C
 	if err != nil {
 		return nil, fmt.Errorf("loading l2 head: %w", err)
 	}
+	logger.Info("Loaded L2 head", "hash", head.Hash(), "number", head.Number())
 	return &OracleBackedL2Chain{
 		log:      logger,
 		oracle:   oracle,

op-program/host/cmd/main_test.go

@@ -13,7 +13,9 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var l2HeadValue = "0x6303578b1fa9480389c51bbcef6fe045bb877da39740819e9eb5f36f94949bd0"
+// Use HexToHash(...).Hex() to ensure the strings are the correct length for a hash
+var l1HeadValue = common.HexToHash("0x111111").Hex()
+var l2HeadValue = common.HexToHash("0x222222").Hex()
 
 func TestLogLevel(t *testing.T) {
 	t.Run("RejectInvalid", func(t *testing.T) {
@@ -32,7 +34,8 @@ func TestLogLevel(t *testing.T) {
 
 func TestDefaultCLIOptionsMatchDefaultConfig(t *testing.T) {
 	cfg := configForArgs(t, addRequiredArgs())
-	require.Equal(t, config.NewConfig(&chaincfg.Goerli, "genesis.json", common.HexToHash(l2HeadValue)), cfg)
+	defaultCfg := config.NewConfig(&chaincfg.Goerli, "genesis.json", common.HexToHash(l1HeadValue), common.HexToHash(l2HeadValue))
+	require.Equal(t, defaultCfg, cfg)
 }
 
 func TestNetwork(t *testing.T) {
@@ -102,6 +105,21 @@ func TestL2Head(t *testing.T) {
 	})
 }
 
+func TestL1Head(t *testing.T) {
+	t.Run("Required", func(t *testing.T) {
+		verifyArgsInvalid(t, "flag l1.head is required", addRequiredArgsExcept("--l1.head"))
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		cfg := configForArgs(t, replaceRequiredArg("--l1.head", l1HeadValue))
+		require.Equal(t, common.HexToHash(l1HeadValue), cfg.L1Head)
+	})
+
+	t.Run("Invalid", func(t *testing.T) {
+		verifyArgsInvalid(t, config.ErrInvalidL1Head.Error(), replaceRequiredArg("--l1.head", "something"))
+	})
+}
+
 func TestL1(t *testing.T) {
 	expected := "https://example.com:8545"
 	cfg := configForArgs(t, addRequiredArgs("--l1", expected))
@@ -149,7 +167,8 @@ func TestL1RPCKind(t *testing.T) {
 // Offline support will be added later, but for now it just bails out with an error
 func TestOfflineModeNotSupported(t *testing.T) {
 	logger := log.New()
-	err := FaultProofProgram(logger, config.NewConfig(&chaincfg.Goerli, "genesis.json", common.HexToHash(l2HeadValue)))
+	cfg := config.NewConfig(&chaincfg.Goerli, "genesis.json", common.HexToHash(l1HeadValue), common.HexToHash(l2HeadValue))
+	err := FaultProofProgram(logger, cfg)
 	require.ErrorContains(t, err, "offline mode not supported")
 }
 
@@ -199,8 +218,9 @@ func replaceRequiredArg(name string, value string) []string {
 func requiredArgs() map[string]string {
 	return map[string]string{
 		"--network":    "goerli",
-		"--l2.genesis": "genesis.json",
+		"--l1.head":    l1HeadValue,
 		"--l2.head":    l2HeadValue,
+		"--l2.genesis": "genesis.json",
 	}
 }