les, light: implement ODR transaction lookup by hash (#19069)

* les, light: implement ODR transaction lookup by hash

* les: delete useless file

* internal/ethapi: always use backend to find transaction

* les, eth, internal/ethapi: renamed GetCanonicalTransaction to GetTransaction

* light: add canonical header verification to GetTransaction

eth/api_backend.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/bloombits"
+	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -178,6 +179,11 @@ func (b *EthAPIBackend) GetPoolTransaction(hash common.Hash) *types.Transaction
 	return b.eth.txPool.Get(hash)
 }
 
+func (b *EthAPIBackend) GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error) {
+	tx, blockHash, blockNumber, index := rawdb.ReadTransaction(b.eth.ChainDb(), txHash)
+	return tx, blockHash, blockNumber, index, nil
+}
+
 func (b *EthAPIBackend) GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error) {
 	return b.eth.txPool.State().GetNonce(addr), nil
 }

internal/ethapi/api.go

@@ -1155,25 +1155,32 @@ func (s *PublicTransactionPoolAPI) GetTransactionCount(ctx context.Context, addr
 }
 
 // GetTransactionByHash returns the transaction for the given hash
-func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) *RPCTransaction {
+func (s *PublicTransactionPoolAPI) GetTransactionByHash(ctx context.Context, hash common.Hash) (*RPCTransaction, error) {
 	// Try to return an already finalized transaction
-	if tx, blockHash, blockNumber, index := rawdb.ReadTransaction(s.b.ChainDb(), hash); tx != nil {
+	tx, blockHash, blockNumber, index, err := s.b.GetTransaction(ctx, hash)
-		return newRPCTransaction(tx, blockHash, blockNumber, index)
+	if err != nil {
+		return nil, err
+	}
+	if tx != nil {
+		return newRPCTransaction(tx, blockHash, blockNumber, index), nil
 	}
 	// No finalized transaction, try to retrieve it from the pool
 	if tx := s.b.GetPoolTransaction(hash); tx != nil {
-		return newRPCPendingTransaction(tx)
+		return newRPCPendingTransaction(tx), nil
 	}
+
 	// Transaction unknown, return as such
-	return nil
+	return nil, nil
 }
 
 // GetRawTransactionByHash returns the bytes of the transaction for the given hash.
 func (s *PublicTransactionPoolAPI) GetRawTransactionByHash(ctx context.Context, hash common.Hash) (hexutil.Bytes, error) {
-	var tx *types.Transaction
-
 	// Retrieve a finalized transaction, or a pooled otherwise
-	if tx, _, _, _ = rawdb.ReadTransaction(s.b.ChainDb(), hash); tx == nil {
+	tx, _, _, _, err := s.b.GetTransaction(ctx, hash)
+	if err != nil {
+		return nil, err
+	}
+	if tx == nil {
 		if tx = s.b.GetPoolTransaction(hash); tx == nil {
 			// Transaction not found anywhere, abort
 			return nil, nil

internal/ethapi/backend.go

@@ -62,6 +62,7 @@ type Backend interface {
 
 	// TxPool API
 	SendTx(ctx context.Context, signedTx *types.Transaction) error
+	GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error)
 	GetPoolTransactions() (types.Transactions, error)
 	GetPoolTransaction(txHash common.Hash) *types.Transaction
 	GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)

les/api_backend.go

@@ -132,6 +132,10 @@ func (b *LesApiBackend) GetPoolTransaction(txHash common.Hash) *types.Transactio
 	return b.eth.txPool.GetTransaction(txHash)
 }
 
+func (b *LesApiBackend) GetTransaction(ctx context.Context, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error) {
+	return light.GetTransaction(ctx, b.eth.odr, txHash)
+}
+
 func (b *LesApiBackend) GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error) {
 	return b.eth.txPool.GetNonce(ctx, addr)
 }

les/backend.go

@@ -114,9 +114,9 @@ func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
 	if leth.config.ULC != nil {
 		trustedNodes = leth.config.ULC.TrustedServers
 	}
-	leth.relay = NewLesTxRelay(peers, leth.reqDist)
 	leth.serverPool = newServerPool(chainDb, quitSync, &leth.wg, trustedNodes)
 	leth.retriever = newRetrieveManager(peers, leth.reqDist, leth.serverPool)
+	leth.relay = NewLesTxRelay(peers, leth.retriever)
 
 	leth.odr = NewLesOdr(chainDb, light.DefaultClientIndexerConfig, leth.retriever)
 	leth.chtIndexer = light.NewChtIndexer(chainDb, leth.odr, params.CHTFrequency, params.HelperTrieConfirmations)
@@ -271,6 +271,7 @@ func (s *LightEthereum) Start(srvr *p2p.Server) error {
 // Ethereum protocol.
 func (s *LightEthereum) Stop() error {
 	s.odr.Stop()
+	s.relay.Stop()
 	s.bloomIndexer.Close()
 	s.chtIndexer.Close()
 	s.blockchain.Stop()

les/handler.go

@@ -979,7 +979,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			return errResp(ErrRequestRejected, "")
 		}
 		go func() {
-			stats := make([]txStatus, len(req.Txs))
+			stats := make([]light.TxStatus, len(req.Txs))
 			for i, tx := range req.Txs {
 				if i != 0 && !task.waitOrStop() {
 					return
@@ -1014,7 +1014,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			return errResp(ErrRequestRejected, "")
 		}
 		go func() {
-			stats := make([]txStatus, len(req.Hashes))
+			stats := make([]light.TxStatus, len(req.Hashes))
 			for i, hash := range req.Hashes {
 				if i != 0 && !task.waitOrStop() {
 					return
@@ -1032,7 +1032,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		p.Log().Trace("Received tx status response")
 		var resp struct {
 			ReqID, BV uint64
-			Status    []txStatus
+			Status    []light.TxStatus
 		}
 		if err := msg.Decode(&resp); err != nil {
 			return errResp(ErrDecode, "msg %v: %v", msg, err)
@@ -1040,6 +1040,13 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 
 		p.fcServer.ReceivedReply(resp.ReqID, resp.BV)
 
+		p.Log().Trace("Received helper trie proof response")
+		deliverMsg = &Msg{
+			MsgType: MsgTxStatus,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Status,
+		}
+
 	default:
 		p.Log().Trace("Received unknown message", "code", msg.Code)
 		return errResp(ErrInvalidMsgCode, "%v", msg.Code)
@@ -1097,8 +1104,8 @@ func (pm *ProtocolManager) getHelperTrieAuxData(req HelperTrieReq) []byte {
 	return nil
 }
 
-func (pm *ProtocolManager) txStatus(hash common.Hash) txStatus {
+func (pm *ProtocolManager) txStatus(hash common.Hash) light.TxStatus {
-	var stat txStatus
+	var stat light.TxStatus
 	stat.Status = pm.txpool.Status([]common.Hash{hash})[0]
 	// If the transaction is unknown to the pool, try looking it up locally
 	if stat.Status == core.TxStatusUnknown {

les/handler_test.go

@@ -443,7 +443,7 @@ func TestTransactionStatusLes2(t *testing.T) {
 
 	var reqID uint64
 
-	test := func(tx *types.Transaction, send bool, expStatus txStatus) {
+	test := func(tx *types.Transaction, send bool, expStatus light.TxStatus) {
 		reqID++
 		if send {
 			cost := peer.GetRequestCost(SendTxV2Msg, 1)
@@ -452,7 +452,7 @@ func TestTransactionStatusLes2(t *testing.T) {
 			cost := peer.GetRequestCost(GetTxStatusMsg, 1)
 			sendRequest(peer.app, GetTxStatusMsg, reqID, cost, []common.Hash{tx.Hash()})
 		}
-		if err := expectResponse(peer.app, TxStatusMsg, reqID, testBufLimit, []txStatus{expStatus}); err != nil {
+		if err := expectResponse(peer.app, TxStatusMsg, reqID, testBufLimit, []light.TxStatus{expStatus}); err != nil {
 			t.Errorf("transaction status mismatch")
 		}
 	}
@@ -461,20 +461,20 @@ func TestTransactionStatusLes2(t *testing.T) {
 
 	// test error status by sending an underpriced transaction
 	tx0, _ := types.SignTx(types.NewTransaction(0, acc1Addr, big.NewInt(10000), params.TxGas, nil, nil), signer, testBankKey)
-	test(tx0, true, txStatus{Status: core.TxStatusUnknown, Error: core.ErrUnderpriced.Error()})
+	test(tx0, true, light.TxStatus{Status: core.TxStatusUnknown, Error: core.ErrUnderpriced.Error()})
 
 	tx1, _ := types.SignTx(types.NewTransaction(0, acc1Addr, big.NewInt(10000), params.TxGas, big.NewInt(100000000000), nil), signer, testBankKey)
-	test(tx1, false, txStatus{Status: core.TxStatusUnknown}) // query before sending, should be unknown
+	test(tx1, false, light.TxStatus{Status: core.TxStatusUnknown}) // query before sending, should be unknown
-	test(tx1, true, txStatus{Status: core.TxStatusPending})  // send valid processable tx, should return pending
+	test(tx1, true, light.TxStatus{Status: core.TxStatusPending})  // send valid processable tx, should return pending
-	test(tx1, true, txStatus{Status: core.TxStatusPending})  // adding it again should not return an error
+	test(tx1, true, light.TxStatus{Status: core.TxStatusPending})  // adding it again should not return an error
 
 	tx2, _ := types.SignTx(types.NewTransaction(1, acc1Addr, big.NewInt(10000), params.TxGas, big.NewInt(100000000000), nil), signer, testBankKey)
 	tx3, _ := types.SignTx(types.NewTransaction(2, acc1Addr, big.NewInt(10000), params.TxGas, big.NewInt(100000000000), nil), signer, testBankKey)
 	// send transactions in the wrong order, tx3 should be queued
-	test(tx3, true, txStatus{Status: core.TxStatusQueued})
+	test(tx3, true, light.TxStatus{Status: core.TxStatusQueued})
-	test(tx2, true, txStatus{Status: core.TxStatusPending})
+	test(tx2, true, light.TxStatus{Status: core.TxStatusPending})
 	// query again, now tx3 should be pending too
-	test(tx3, false, txStatus{Status: core.TxStatusPending})
+	test(tx3, false, light.TxStatus{Status: core.TxStatusPending})
 
 	// generate and add a block with tx1 and tx2 included
 	gchain, _ := core.GenerateChain(params.TestChainConfig, chain.GetBlockByNumber(0), ethash.NewFaker(), db, 1, func(i int, block *core.BlockGen) {
@@ -497,8 +497,8 @@ func TestTransactionStatusLes2(t *testing.T) {
 
 	// check if their status is included now
 	block1hash := rawdb.ReadCanonicalHash(db, 1)
-	test(tx1, false, txStatus{Status: core.TxStatusIncluded, Lookup: &rawdb.LegacyTxLookupEntry{BlockHash: block1hash, BlockIndex: 1, Index: 0}})
+	test(tx1, false, light.TxStatus{Status: core.TxStatusIncluded, Lookup: &rawdb.LegacyTxLookupEntry{BlockHash: block1hash, BlockIndex: 1, Index: 0}})
-	test(tx2, false, txStatus{Status: core.TxStatusIncluded, Lookup: &rawdb.LegacyTxLookupEntry{BlockHash: block1hash, BlockIndex: 1, Index: 1}})
+	test(tx2, false, light.TxStatus{Status: core.TxStatusIncluded, Lookup: &rawdb.LegacyTxLookupEntry{BlockHash: block1hash, BlockIndex: 1, Index: 1}})
 
 	// create a reorg that rolls them back
 	gchain, _ = core.GenerateChain(params.TestChainConfig, chain.GetBlockByNumber(0), ethash.NewFaker(), db, 2, func(i int, block *core.BlockGen) {})
@@ -516,6 +516,6 @@ func TestTransactionStatusLes2(t *testing.T) {
 		t.Fatalf("pending count mismatch: have %d, want 3", pending)
 	}
 	// check if their status is pending again
-	test(tx1, false, txStatus{Status: core.TxStatusPending})
+	test(tx1, false, light.TxStatus{Status: core.TxStatusPending})
-	test(tx2, false, txStatus{Status: core.TxStatusPending})
+	test(tx2, false, light.TxStatus{Status: core.TxStatusPending})
 }

les/helper_test.go

@@ -148,6 +148,7 @@ func newTestProtocolManager(lightSync bool, blocks int, generator func(int, *cor
 		}
 		genesis = gspec.MustCommit(db)
 		chain   BlockChain
+		pool    txPool
 	)
 	if peers == nil {
 		peers = newPeerSet()
@@ -162,13 +163,14 @@ func newTestProtocolManager(lightSync bool, blocks int, generator func(int, *cor
 			panic(err)
 		}
 		chain = blockchain
+		pool = core.NewTxPool(core.DefaultTxPoolConfig, gspec.Config, blockchain)
 	}
 
 	indexConfig := light.TestServerIndexerConfig
 	if lightSync {
 		indexConfig = light.TestClientIndexerConfig
 	}
-	pm, err := NewProtocolManager(gspec.Config, indexConfig, lightSync, NetworkId, evmux, engine, peers, chain, nil, db, odr, nil, nil, make(chan struct{}), new(sync.WaitGroup), ulcConfig)
+	pm, err := NewProtocolManager(gspec.Config, indexConfig, lightSync, NetworkId, evmux, engine, peers, chain, pool, db, odr, nil, nil, make(chan struct{}), new(sync.WaitGroup), ulcConfig)
 	if err != nil {
 		return nil, err
 	}

les/odr.go

@@ -86,6 +86,7 @@ const (
 	MsgReceipts
 	MsgProofsV2
 	MsgHelperTrieProofs
+	MsgTxStatus
 )
 
 // Msg encodes a LES message that delivers reply data for a request

les/odr_requests.go

@@ -66,6 +66,8 @@ func LesRequest(req light.OdrRequest) LesOdrRequest {
 		return (*ChtRequest)(r)
 	case *light.BloomRequest:
 		return (*BloomRequest)(r)
+	case *light.TxStatusRequest:
+		return (*TxStatusRequest)(r)
 	default:
 		return nil
 	}
@@ -471,6 +473,44 @@ func (r *BloomRequest) Validate(db ethdb.Database, msg *Msg) error {
 	return nil
 }
 
+// TxStatusRequest is the ODR request type for transaction status
+type TxStatusRequest light.TxStatusRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (r *TxStatusRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetTxStatusMsg, len(r.Hashes))
+}
+
+// CanSend tells if a certain peer is suitable for serving the given request
+func (r *TxStatusRequest) CanSend(peer *peer) bool {
+	return peer.version >= lpv2
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (r *TxStatusRequest) Request(reqID uint64, peer *peer) error {
+	peer.Log().Debug("Requesting transaction status", "count", len(r.Hashes))
+	return peer.RequestTxStatus(reqID, r.GetCost(peer), r.Hashes)
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (r *TxStatusRequest) Validate(db ethdb.Database, msg *Msg) error {
+	log.Debug("Validating transaction status", "count", len(r.Hashes))
+
+	// Ensure we have a correct message with a single block body
+	if msg.MsgType != MsgTxStatus {
+		return errInvalidMessageType
+	}
+	status := msg.Obj.([]light.TxStatus)
+	if len(status) != len(r.Hashes) {
+		return errInvalidEntryCount
+	}
+	r.Status = status
+	return nil
+}
+
 // readTraceDB stores the keys of database reads. We use this to check that received node
 // sets contain only the trie nodes necessary to make proofs pass.
 type readTraceDB struct {

les/odr_test.go

@@ -38,7 +38,7 @@ import (
 
 type odrTestFn func(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte
 
-func TestOdrGetBlockLes2(t *testing.T) { testOdr(t, 2, 1, odrGetBlock) }
+func TestOdrGetBlockLes2(t *testing.T) { testOdr(t, 2, 1, true, odrGetBlock) }
 
 func odrGetBlock(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
 	var block *types.Block
@@ -54,7 +54,7 @@ func odrGetBlock(ctx context.Context, db ethdb.Database, config *params.ChainCon
 	return rlp
 }
 
-func TestOdrGetReceiptsLes2(t *testing.T) { testOdr(t, 2, 1, odrGetReceipts) }
+func TestOdrGetReceiptsLes2(t *testing.T) { testOdr(t, 2, 1, true, odrGetReceipts) }
 
 func odrGetReceipts(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
 	var receipts types.Receipts
@@ -74,7 +74,7 @@ func odrGetReceipts(ctx context.Context, db ethdb.Database, config *params.Chain
 	return rlp
 }
 
-func TestOdrAccountsLes2(t *testing.T) { testOdr(t, 2, 1, odrAccounts) }
+func TestOdrAccountsLes2(t *testing.T) { testOdr(t, 2, 1, true, odrAccounts) }
 
 func odrAccounts(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
 	dummyAddr := common.HexToAddress("1234567812345678123456781234567812345678")
@@ -102,7 +102,7 @@ func odrAccounts(ctx context.Context, db ethdb.Database, config *params.ChainCon
 	return res
 }
 
-func TestOdrContractCallLes2(t *testing.T) { testOdr(t, 2, 2, odrContractCall) }
+func TestOdrContractCallLes2(t *testing.T) { testOdr(t, 2, 2, true, odrContractCall) }
 
 type callmsg struct {
 	types.Message
@@ -151,8 +151,32 @@ func odrContractCall(ctx context.Context, db ethdb.Database, config *params.Chai
 	return res
 }
 
+func TestOdrTxStatusLes2(t *testing.T) { testOdr(t, 2, 1, false, odrTxStatus) }
+
+func odrTxStatus(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
+	var txs types.Transactions
+	if bc != nil {
+		block := bc.GetBlockByHash(bhash)
+		txs = block.Transactions()
+	} else {
+		if block, _ := lc.GetBlockByHash(ctx, bhash); block != nil {
+			btxs := block.Transactions()
+			txs = make(types.Transactions, len(btxs))
+			for i, tx := range btxs {
+				var err error
+				txs[i], _, _, _, err = light.GetTransaction(ctx, lc.Odr(), tx.Hash())
+				if err != nil {
+					return nil
+				}
+			}
+		}
+	}
+	rlp, _ := rlp.EncodeToBytes(txs)
+	return rlp
+}
+
 // testOdr tests odr requests whose validation guaranteed by block headers.
-func testOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
+func testOdr(t *testing.T, protocol int, expFail uint64, checkCached bool, fn odrTestFn) {
 	// Assemble the test environment
 	server, client, tearDown := newClientServerEnv(t, 4, protocol, nil, true)
 	defer tearDown()
@@ -193,9 +217,10 @@ func testOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
 	client.rPeer.hasBlock = func(common.Hash, uint64, bool) bool { return true }
 	client.peers.lock.Unlock()
 	test(5)
-
+	if checkCached {
 		// still expect all retrievals to pass, now data should be cached locally
 		client.peers.Unregister(client.rPeer.id)
 		time.Sleep(time.Millisecond * 10) // ensure that all peerSetNotify callbacks are executed
 		test(5)
 	}
+}

les/peer.go

@@ -317,7 +317,7 @@ func (p *peer) ReplyHelperTrieProofs(reqID uint64, resp HelperTrieResps) *reply
 }
 
 // ReplyTxStatus creates a reply with a batch of transaction status records, corresponding to the ones requested.
-func (p *peer) ReplyTxStatus(reqID uint64, stats []txStatus) *reply {
+func (p *peer) ReplyTxStatus(reqID uint64, stats []light.TxStatus) *reply {
 	data, _ := rlp.EncodeToBytes(stats)
 	return &reply{p.rw, TxStatusMsg, reqID, data}
 }

les/protocol.go

@@ -24,8 +24,6 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/rlp"
@@ -227,9 +225,3 @@ type CodeData []struct {
 }
 
 type proofsData [][]rlp.RawValue
-
-type txStatus struct {
-	Status core.TxStatus
-	Lookup *rawdb.LegacyTxLookupEntry `rlp:"nil"`
-	Error  string
-}

les/txrelay.go

@@ -17,6 +17,7 @@
 package les
 
 import (
+	"context"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -36,21 +37,27 @@ type LesTxRelay struct {
 	peerList     []*peer
 	peerStartPos int
 	lock         sync.RWMutex
+	stop         chan struct{}
 
-	reqDist *requestDistributor
+	retriever *retrieveManager
 }
 
-func NewLesTxRelay(ps *peerSet, reqDist *requestDistributor) *LesTxRelay {
+func NewLesTxRelay(ps *peerSet, retriever *retrieveManager) *LesTxRelay {
 	r := &LesTxRelay{
 		txSent:    make(map[common.Hash]*ltrInfo),
 		txPending: make(map[common.Hash]struct{}),
 		ps:        ps,
-		reqDist:   reqDist,
+		retriever: retriever,
+		stop:      make(chan struct{}),
 	}
 	ps.notify(r)
 	return r
 }
 
+func (self *LesTxRelay) Stop() {
+	close(self.stop)
+}
+
 func (self *LesTxRelay) registerPeer(p *peer) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -132,7 +139,7 @@ func (self *LesTxRelay) send(txs types.Transactions, count int) {
 				return func() { peer.SendTxs(reqID, cost, enc) }
 			},
 		}
-		self.reqDist.queue(rq)
+		go self.retriever.retrieve(context.Background(), reqID, rq, func(p distPeer, msg *Msg) error { return nil }, self.stop)
 	}
 }
 

light/odr.go

@@ -175,3 +175,20 @@ func (req *BloomRequest) StoreResult(db ethdb.Database) {
 		rawdb.WriteBloomBits(db, req.BitIdx, sectionIdx, sectionHead, req.BloomBits[i])
 	}
 }
+
+// TxStatus describes the status of a transaction
+type TxStatus struct {
+	Status core.TxStatus
+	Lookup *rawdb.LegacyTxLookupEntry `rlp:"nil"`
+	Error  string
+}
+
+// TxStatusRequest is the ODR request type for retrieving transaction status
+type TxStatusRequest struct {
+	OdrRequest
+	Hashes []common.Hash
+	Status []TxStatus
+}
+
+// StoreResult stores the retrieved data in local database
+func (req *TxStatusRequest) StoreResult(db ethdb.Database) {}

light/odr_util.go

@@ -21,6 +21,7 @@ import (
 	"context"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -227,3 +228,23 @@ func GetBloomBits(ctx context.Context, odr OdrBackend, bitIdx uint, sectionIdxLi
 		return result, nil
 	}
 }
+
+// GetTransaction retrieves a canonical transaction by hash and also returns its position in the chain
+func GetTransaction(ctx context.Context, odr OdrBackend, txHash common.Hash) (*types.Transaction, common.Hash, uint64, uint64, error) {
+	r := &TxStatusRequest{Hashes: []common.Hash{txHash}}
+	if err := odr.Retrieve(ctx, r); err != nil || r.Status[0].Status != core.TxStatusIncluded {
+		return nil, common.Hash{}, 0, 0, err
+	} else {
+		pos := r.Status[0].Lookup
+		// first ensure that we have the header, otherwise block body retrieval will fail
+		// also verify if this is a canonical block by getting the header by number and checking its hash
+		if header, err := GetHeaderByNumber(ctx, odr, pos.BlockIndex); err != nil || header.Hash() != pos.BlockHash {
+			return nil, common.Hash{}, 0, 0, err
+		}
+		if body, err := GetBody(ctx, odr, pos.BlockHash, pos.BlockIndex); err != nil || uint64(len(body.Transactions)) <= pos.Index || body.Transactions[pos.Index].Hash() != txHash {
+			return nil, common.Hash{}, 0, 0, err
+		} else {
+			return body.Transactions[pos.Index], pos.BlockHash, pos.BlockIndex, pos.Index, nil
+		}
+	}
+}