les, light: support multi headers fetching

les/odr_requests.go

@@ -22,6 +22,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
@@ -352,9 +353,9 @@ type ChtRequest light.ChtRequest
 func (r *ChtRequest) GetCost(peer *peer) uint64 {
 	switch peer.version {
 	case lpv1:
-		return peer.GetRequestCost(GetHeaderProofsMsg, 1)
+		return peer.GetRequestCost(GetHeaderProofsMsg, len(r.BlockNum))
 	case lpv2:
-		return peer.GetRequestCost(GetHelperTrieProofsMsg, 1)
+		return peer.GetRequestCost(GetHelperTrieProofsMsg, len(r.BlockNum))
 	default:
 		panic(nil)
 	}
@@ -371,26 +372,33 @@ func (r *ChtRequest) CanSend(peer *peer, config *light.IndexerConfig) bool {
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)
 func (r *ChtRequest) Request(reqID uint64, peer *peer, config *light.IndexerConfig) error {
 	peer.Log().Debug("Requesting CHT", "cht", r.ChtNum, "block", r.BlockNum)
-	var encNum [8]byte
-	binary.BigEndian.PutUint64(encNum[:], r.BlockNum)
-	req := HelperTrieReq{
+	var (
+		encNum [8]byte
+		reqs   []HelperTrieReq
+	)
+	for _, num := range r.BlockNum {
+		binary.BigEndian.PutUint64(encNum[:], num)
+		reqs = append(reqs, HelperTrieReq{
 			Type:    htCanonical,
 			TrieIdx: r.ChtNum,
 			Key:     encNum[:],
 			AuxReq:  auxHeader,
+		})
 	}
 	switch peer.version {
 	case lpv1:
-		var reqsV1 ChtReq
-		if req.Type != htCanonical || req.AuxReq != auxHeader || len(req.Key) != 8 {
+		var reqsV1 []ChtReq
+		for _, r := range reqs {
+			if r.Type != htCanonical || r.AuxReq != auxHeader || len(r.Key) != 8 {
 				return fmt.Errorf("Request invalid in LES/1 mode")
 			}
-		blockNum := binary.BigEndian.Uint64(req.Key)
+			blockNum := binary.BigEndian.Uint64(r.Key)
 			// convert HelperTrie request to old CHT request
-		reqsV1 = ChtReq{ChtNum: (req.TrieIdx + 1) * (config.ChtSize / config.PairChtSize), BlockNum: blockNum, FromLevel: req.FromLevel}
-		return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), []ChtReq{reqsV1})
+			reqsV1 = append(reqsV1, ChtReq{ChtNum: (r.TrieIdx+1)*(config.ChtSize/config.PairChtSize), BlockNum: blockNum, FromLevel: r.FromLevel})
+		}
+		return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), reqsV1)
 	case lpv2:
-		return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), []HelperTrieReq{req})
+		return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), reqs)
 	default:
 		panic(nil)
 	}
@@ -404,73 +412,88 @@ func (r *ChtRequest) Validate(db ethdb.Database, msg *Msg) error {
 
 	switch msg.MsgType {
 	case MsgHeaderProofs: // LES/1 backwards compatibility
-		proofs := msg.Obj.([]ChtResp)
-		if len(proofs) != 1 {
+		resps := msg.Obj.([]ChtResp)
+		if len(resps) != len(r.BlockNum) {
 			return errInvalidEntryCount
 		}
-		proof := proofs[0]
-
+		var (
+			headers   []*types.Header
+			tds       []*big.Int
+			encNumber [8]byte
+			node      light.ChtNode
+			nodeset   = light.NewNodeSet()
+		)
+		for i, num := range r.BlockNum {
+			resp := resps[i]
 			// Verify the CHT
-		var encNumber [8]byte
-		binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
-
-		value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], light.NodeList(proof.Proof).NodeSet())
+			binary.BigEndian.PutUint64(encNumber[:], num)
+			value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], light.NodeList(resp.Proof).NodeSet())
 			if err != nil {
 				return err
 			}
-		var node light.ChtNode
 			if err := rlp.DecodeBytes(value, &node); err != nil {
 				return err
 			}
-		if node.Hash != proof.Header.Hash() {
+			if node.Hash != resp.Header.Hash() {
 				return errCHTHashMismatch
 			}
-		// Verifications passed, store and return
-		r.Header = proof.Header
-		r.Proof = light.NodeList(proof.Proof).NodeSet()
-		r.Td = node.Td
+			if num != resp.Header.Number.Uint64() {
+				return errCHTNumberMismatch
+			}
+			// Verifications passed, store temporarily
+			headers = append(headers, resp.Header)
+			tds = append(tds, node.Td)
+			light.NodeList(resp.Proof).Store(nodeset)
+		}
+		r.Header = headers
+		r.Td = tds
+		r.Proof = nodeset
+
 	case MsgHelperTrieProofs:
+		// Check if the number of items in the response is the same as we requested.
 		resp := msg.Obj.(HelperTrieResps)
-		if len(resp.AuxData) != 1 {
+		if len(resp.AuxData) != len(r.BlockNum) {
 			return errInvalidEntryCount
 		}
-		nodeSet := resp.Proofs.NodeSet()
-		headerEnc := resp.AuxData[0]
-		if len(headerEnc) == 0 {
+		var (
+			headers   []*types.Header
+			tds       []*big.Int
+			encNumber [8]byte
+			node      light.ChtNode
+			nodeSet   = resp.Proofs.NodeSet()
+		)
+		for i, num := range r.BlockNum {
+			enc := resp.AuxData[i]
+			if len(enc) == 0 {
 				return errHeaderUnavailable
 			}
 			header := new(types.Header)
-		if err := rlp.DecodeBytes(headerEnc, header); err != nil {
+			if err := rlp.DecodeBytes(enc, header); err != nil {
 				return errHeaderUnavailable
 			}
-
 			// Verify the CHT
-		var encNumber [8]byte
-		binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
-
-		reads := &readTraceDB{db: nodeSet}
-		value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], reads)
+			binary.BigEndian.PutUint64(encNumber[:], num)
+			value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], nodeSet)
 			if err != nil {
 				return fmt.Errorf("merkle proof verification failed: %v", err)
 			}
-		if len(reads.reads) != nodeSet.KeyCount() {
-			return errUselessNodes
-		}
-
-		var node light.ChtNode
 			if err := rlp.DecodeBytes(value, &node); err != nil {
 				return err
 			}
 			if node.Hash != header.Hash() {
 				return errCHTHashMismatch
 			}
-		if r.BlockNum != header.Number.Uint64() {
+			if num != header.Number.Uint64() {
 				return errCHTNumberMismatch
 			}
-		// Verifications passed, store and return
-		r.Header = header
+			// Verifications passed, store temporarily
+			headers = append(headers, header)
+			tds = append(tds, node.Td)
+		}
+		r.Header = headers
+		r.Td = tds
 		r.Proof = nodeSet
-		r.Td = node.Td
+
 	default:
 		return errInvalidMessageType
 	}

light/odr.go

@@ -133,20 +133,26 @@ func (req *ReceiptsRequest) StoreResult(db ethdb.Database, config *IndexerConfig
 // ChtRequest is the ODR request type for state/storage trie entries
 type ChtRequest struct {
 	OdrRequest
-	ChtNum, BlockNum uint64
+	ChtNum   uint64
 	ChtRoot  common.Hash
-	Header           *types.Header
-	Td               *big.Int
+	BlockNum []uint64
+	Header   []*types.Header
+	Td       []*big.Int
 	Proof    *NodeSet
 }
 
 // StoreResult stores the retrieved data in local database
 func (req *ChtRequest) StoreResult(db ethdb.Database, config *IndexerConfig) {
-	hash, num := req.Header.Hash(), req.Header.Number.Uint64()
+	// The block number, header, td, proof length consistency has been verified
+	// in the validation phase.
+	for index := range req.BlockNum {
+		header := req.Header[index]
+		hash, num := header.Hash(), header.Number.Uint64()
 
-	rawdb.WriteHeader(db, req.Header)
-	rawdb.WriteTd(db, hash, num, req.Td)
+		rawdb.WriteHeader(db, header)
+		rawdb.WriteTd(db, hash, num, req.Td[index])
 		rawdb.WriteCanonicalHash(db, hash, num)
+	}
 }
 
 // BloomRequest is the ODR request type for retrieving bloom filters from a CHT structure

light/odr_util.go

@@ -62,11 +62,12 @@ func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*typ
 	if number >= chtCount*odr.IndexerConfig().ChtSize {
 		return nil, ErrNoTrustedCht
 	}
-	r := &ChtRequest{ChtRoot: GetChtRoot(db, chtCount-1, sectionHead), ChtNum: chtCount - 1, BlockNum: number}
+	r := &ChtRequest{ChtRoot: GetChtRoot(db, chtCount-1, sectionHead), ChtNum: chtCount - 1, BlockNum: []uint64{number}}
 	if err := odr.Retrieve(ctx, r); err != nil {
 		return nil, err
 	}
-	return r.Header, nil
+	// Response item number has been checked in validation stage, no extra checking needed.
+	return r.Header[0], nil
 }
 
 func GetCanonicalHash(ctx context.Context, odr OdrBackend, number uint64) (common.Hash, error) {