eth/downloader: finish porting the sync logic to eth/62

core/types/block.go

@@ -357,6 +357,20 @@ func (b *Block) WithMiningResult(nonce uint64, mixDigest common.Hash) *Block {
 	}
 }
 
+// WithBody returns a new block with the given transaction and uncle contents.
+func (b *Block) WithBody(transactions []*Transaction, uncles []*Header) *Block {
+	block := &Block{
+		header:       copyHeader(b.header),
+		transactions: make([]*Transaction, len(transactions)),
+		uncles:       make([]*Header, len(uncles)),
+	}
+	copy(block.transactions, transactions)
+	for i := range uncles {
+		block.uncles[i] = copyHeader(uncles[i])
+	}
+	return block
+}
+
 // Implement pow.Block
 
 func (b *Block) Hash() common.Hash {

eth/downloader/downloader.go

@@ -19,7 +19,6 @@ package downloader
 
 import (
 	"errors"
-	"fmt"
 	"math"
 	"math/big"
 	"sync"
@@ -27,12 +26,10 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
-	"gopkg.in/fatih/set.v0"
 )
 
 const (
@@ -41,20 +38,22 @@ const (
 )
 
 var (
-	MinHashFetch     = 512 // Minimum amount of hashes to not consider a peer stalling
 	MaxHashFetch     = 512 // Amount of hashes to be fetched per retrieval request
 	MaxBlockFetch    = 128 // Amount of blocks to be fetched per retrieval request
 	MaxHeaderFetch   = 256 // Amount of block headers to be fetched per retrieval request
+	MaxBodyFetch     = 128 // Amount of block bodies to be fetched per retrieval request
 	MaxStateFetch    = 384 // Amount of node state values to allow fetching per request
 	MaxReceiptsFetch = 384 // Amount of transaction receipts to allow fetching per request
 
-	hashTTL         = 5 * time.Second  // Time it takes for a hash request to time out
+	hashTTL      = 5 * time.Second  // [eth/61] Time it takes for a hash request to time out
-	blockSoftTTL    = 3 * time.Second  // Request completion threshold for increasing or decreasing a peer's bandwidth
+	blockSoftTTL = 3 * time.Second  // [eth/61] Request completion threshold for increasing or decreasing a peer's bandwidth
-	blockHardTTL    = 3 * blockSoftTTL // Maximum time allowance before a block request is considered expired
+	blockHardTTL = 3 * blockSoftTTL // [eth/61] Maximum time allowance before a block request is considered expired
-	crossCheckCycle = time.Second      // Period after which to check for expired cross checks
+	headerTTL    = 5 * time.Second  // [eth/62] Time it takes for a header request to time out
+	bodySoftTTL  = 3 * time.Second  // [eth/62] Request completion threshold for increasing or decreasing a peer's bandwidth
+	bodyHardTTL  = 3 * bodySoftTTL  // [eth/62] Maximum time allowance before a block body request is considered expired
 
-	maxQueuedHashes = 256 * 1024 // Maximum number of hashes to queue for import (DOS protection)
+	maxQueuedHashes  = 256 * 1024 // [eth/61] Maximum number of hashes to queue for import (DOS protection)
-	maxBannedHashes = 4096       // Number of bannable hashes before phasing old ones out
+	maxQueuedHeaders = 256 * 1024 // [eth/62] Maximum number of headers to queue for import (DOS protection)
 	maxBlockProcess  = 256        // Number of blocks to import at once into the chain
 )
 
@@ -63,7 +62,6 @@ var (
 	errUnknownPeer       = errors.New("peer is unknown or unhealthy")
 	errBadPeer           = errors.New("action from bad peer ignored")
 	errStallingPeer      = errors.New("peer is stalling")
-	errBannedHead       = errors.New("peer head hash already banned")
 	errNoPeers           = errors.New("no peers to keep download active")
 	errPendingQueue      = errors.New("pending items in queue")
 	errTimeout           = errors.New("timeout")
@@ -72,9 +70,11 @@ var (
 	errPeersUnavailable  = errors.New("no peers available or all peers tried for block download process")
 	errAlreadyInPool     = errors.New("hash already in pool")
 	errInvalidChain      = errors.New("retrieved hash chain is invalid")
-	errCrossCheckFailed = errors.New("block cross-check failed")
+	errInvalidBody       = errors.New("retrieved block body is invalid")
 	errCancelHashFetch   = errors.New("hash fetching canceled (requested)")
 	errCancelBlockFetch  = errors.New("block downloading canceled (requested)")
+	errCancelHeaderFetch = errors.New("block header fetching canceled (requested)")
+	errCancelBodyFetch   = errors.New("block body downloading canceled (requested)")
 	errNoSyncActive      = errors.New("no sync active")
 )
 
@@ -123,7 +123,6 @@ type Downloader struct {
 
 	queue *queue   // Scheduler for selecting the hashes to download
 	peers *peerSet // Set of active peers from which download can proceed
-	banned *set.Set // Set of hashes we've received and banned
 
 	interrupt int32 // Atomic boolean to signal termination
 
@@ -166,8 +165,7 @@ type Block struct {
 
 // New creates a new downloader to fetch hashes and blocks from remote peers.
 func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock blockRetrievalFn, headBlock headRetrievalFn, insertChain chainInsertFn, dropPeer peerDropFn) *Downloader {
-	// Create the base downloader
+	return &Downloader{
-	downloader := &Downloader{
 		mux:         mux,
 		queue:       newQueue(),
 		peers:       newPeerSet(),
@@ -183,12 +181,6 @@ func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock blockRetrievalFn, he
 		bodyCh:      make(chan bodyPack, 1),
 		processCh:   make(chan bool, 1),
 	}
-	// Inject all the known bad hashes
-	downloader.banned = set.New()
-	for hash, _ := range core.BadHashes {
-		downloader.banned.Add(hash)
-	}
-	return downloader
 }
 
 // Stats retrieves the current status of the downloader.
@@ -224,12 +216,7 @@ func (d *Downloader) Synchronising() bool {
 func (d *Downloader) RegisterPeer(id string, version int, head common.Hash,
 	getRelHashes relativeHashFetcherFn, getAbsHashes absoluteHashFetcherFn, getBlocks blockFetcherFn, // eth/61 callbacks, remove when upgrading
 	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn) error {
-	// If the peer wants to send a banned hash, reject
+
-	if d.banned.Has(head) {
-		glog.V(logger.Debug).Infoln("Register rejected, head hash banned:", id)
-		return errBannedHead
-	}
-	// Otherwise try to construct and register the peer
 	glog.V(logger.Detail).Infoln("Registering peer", id)
 	if err := d.peers.Register(newPeer(id, version, head, getRelHashes, getAbsHashes, getBlocks, getRelHeaders, getAbsHeaders, getBlockBodies)); err != nil {
 		glog.V(logger.Error).Infoln("Register failed:", err)
@@ -261,7 +248,7 @@ func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int) {
 	case errBusy:
 		glog.V(logger.Detail).Infof("Synchronisation already in progress")
 
-	case errTimeout, errBadPeer, errStallingPeer, errBannedHead, errEmptyHashSet, errEmptyHeaderSet, errPeersUnavailable, errInvalidChain, errCrossCheckFailed:
+	case errTimeout, errBadPeer, errStallingPeer, errEmptyHashSet, errEmptyHeaderSet, errPeersUnavailable, errInvalidChain:
 		glog.V(logger.Debug).Infof("Removing peer %v: %v", id, err)
 		d.dropPeer(id)
 
@@ -287,10 +274,6 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int) error
 	}
 	defer atomic.StoreInt32(&d.synchronising, 0)
 
-	// If the head hash is banned, terminate immediately
-	if d.banned.Has(hash) {
-		return errBannedHead
-	}
 	// Post a user notification of the sync (only once per session)
 	if atomic.CompareAndSwapInt32(&d.notified, 0, 1) {
 		glog.V(logger.Info).Infoln("Block synchronisation started")
@@ -358,13 +341,21 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 
 	case eth62:
 		// New eth/62, use forward, concurrent header and block body retrieval algorithm
-		fmt.Println("Looking for common ancestor:", p)
 		number, err := d.findAncestor(p)
 		if err != nil {
 			return err
 		}
-		fmt.Println("Common ancestor:", number)
+		errc := make(chan error, 2)
-		return errBadPeer
+		go func() { errc <- d.fetchHeaders(p, td, number+1) }()
+		go func() { errc <- d.fetchBodies(number + 1) }()
+
+		// If any fetcher fails, cancel the other
+		if err := <-errc; err != nil {
+			d.cancel()
+			<-errc
+			return err
+		}
+		return <-errc
 
 	default:
 		// Something very wrong, stop right here
@@ -548,6 +539,12 @@ func (d *Downloader) fetchHashes61(p *peer, td *big.Int, from uint64) error {
 		case <-d.cancelCh:
 			return errCancelHashFetch
 
+		case <-d.headerCh:
+			// Out of bounds eth/62 block headers received, ignore them
+
+		case <-d.bodyCh:
+			// Out of bounds eth/62 block bodies received, ignore them
+
 		case hashPack := <-d.hashCh:
 			// Make sure the active peer is giving us the hashes
 			if hashPack.peerId != p.id {
@@ -586,7 +583,7 @@ func (d *Downloader) fetchHashes61(p *peer, td *big.Int, from uint64) error {
 			// Otherwise insert all the new hashes, aborting in case of junk
 			glog.V(logger.Detail).Infof("%v: inserting %d hashes from #%d", p, len(hashPack.hashes), from)
 
-			inserts := d.queue.Insert(hashPack.hashes, true)
+			inserts := d.queue.Insert61(hashPack.hashes, true)
 			if len(inserts) != len(hashPack.hashes) {
 				glog.V(logger.Debug).Infof("%v: stale hashes", p)
 				return errBadPeer
@@ -633,24 +630,30 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 		case <-d.cancelCh:
 			return errCancelBlockFetch
 
+		case <-d.headerCh:
+			// Out of bounds eth/62 block headers received, ignore them
+
+		case <-d.bodyCh:
+			// Out of bounds eth/62 block bodies received, ignore them
+
 		case blockPack := <-d.blockCh:
 			// If the peer was previously banned and failed to deliver it's pack
 			// in a reasonable time frame, ignore it's message.
 			if peer := d.peers.Peer(blockPack.peerId); peer != nil {
 				// Deliver the received chunk of blocks, and demote in case of errors
-				err := d.queue.Deliver(blockPack.peerId, blockPack.blocks)
+				err := d.queue.Deliver61(blockPack.peerId, blockPack.blocks)
 				switch err {
 				case nil:
 					// If no blocks were delivered, demote the peer (need the delivery above)
 					if len(blockPack.blocks) == 0 {
 						peer.Demote()
-						peer.SetIdle()
+						peer.SetIdle61()
 						glog.V(logger.Detail).Infof("%s: no blocks delivered", peer)
 						break
 					}
 					// All was successful, promote the peer and potentially start processing
 					peer.Promote()
-					peer.SetIdle()
+					peer.SetIdle61()
 					glog.V(logger.Detail).Infof("%s: delivered %d blocks", peer, len(blockPack.blocks))
 					go d.process()
 
@@ -662,7 +665,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 					// Peer probably timed out with its delivery but came through
 					// in the end, demote, but allow to to pull from this peer.
 					peer.Demote()
-					peer.SetIdle()
+					peer.SetIdle61()
 					glog.V(logger.Detail).Infof("%s: out of bound delivery", peer)
 
 				case errStaleDelivery:
@@ -676,7 +679,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 				default:
 					// Peer did something semi-useful, demote but keep it around
 					peer.Demote()
-					peer.SetIdle()
+					peer.SetIdle61()
 					glog.V(logger.Detail).Infof("%s: delivery partially failed: %v", peer, err)
 					go d.process()
 				}
@@ -734,7 +737,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 				// Reserve a chunk of hashes for a peer. A nil can mean either that
 				// no more hashes are available, or that the peer is known not to
 				// have them.
-				request := d.queue.Reserve(peer, peer.Capacity())
+				request := d.queue.Reserve61(peer, peer.Capacity())
 				if request == nil {
 					continue
 				}
@@ -742,7 +745,7 @@ func (d *Downloader) fetchBlocks61(from uint64) error {
 					glog.Infof("%s: requesting %d blocks", peer, len(request.Hashes))
 				}
 				// Fetch the chunk and make sure any errors return the hashes to the queue
-				if err := peer.Fetch(request); err != nil {
+				if err := peer.Fetch61(request); err != nil {
 					glog.V(logger.Error).Infof("%v: fetch failed, rescheduling", peer)
 					d.queue.Cancel(request)
 				}
@@ -790,8 +793,8 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 			// Make sure the peer actually gave something valid
 			headers := headerPack.headers
 			if len(headers) == 0 {
-				glog.V(logger.Debug).Infof("%v: empty head hash set", p)
+				glog.V(logger.Debug).Infof("%v: empty head header set", p)
-				return 0, errEmptyHashSet
+				return 0, errEmptyHeaderSet
 			}
 			// Check if a common ancestor was found
 			finished = true
@@ -880,6 +883,255 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 	return start, nil
 }
 
+// fetchHeaders keeps retrieving headers from the requested number, until no more
+// are returned, potentially throttling on the way.
+func (d *Downloader) fetchHeaders(p *peer, td *big.Int, from uint64) error {
+	glog.V(logger.Debug).Infof("%v: downloading headers from #%d", p, from)
+
+	// Create a timeout timer, and the associated hash fetcher
+	timeout := time.NewTimer(0) // timer to dump a non-responsive active peer
+	<-timeout.C                 // timeout channel should be initially empty
+	defer timeout.Stop()
+
+	getHeaders := func(from uint64) {
+		glog.V(logger.Detail).Infof("%v: fetching %d headers from #%d", p, MaxHeaderFetch, from)
+
+		go p.getAbsHeaders(from, MaxHeaderFetch, 0, false)
+		timeout.Reset(headerTTL)
+	}
+	// Start pulling headers, until all are exhausted
+	getHeaders(from)
+	gotHeaders := false
+
+	for {
+		select {
+		case <-d.cancelCh:
+			return errCancelHeaderFetch
+
+		case <-d.hashCh:
+			// Out of bounds eth/61 hashes received, ignore them
+
+		case <-d.blockCh:
+			// Out of bounds eth/61 blocks received, ignore them
+
+		case headerPack := <-d.headerCh:
+			// Make sure the active peer is giving us the headers
+			if headerPack.peerId != p.id {
+				glog.V(logger.Debug).Infof("Received headers from incorrect peer (%s)", headerPack.peerId)
+				break
+			}
+			timeout.Stop()
+
+			// If no more headers are inbound, notify the body fetcher and return
+			if len(headerPack.headers) == 0 {
+				glog.V(logger.Debug).Infof("%v: no available headers", p)
+
+				select {
+				case d.processCh <- false:
+				case <-d.cancelCh:
+				}
+				// If no headers were retrieved at all, the peer violated it's TD promise that it had a
+				// better chain compared to ours. The only exception is if it's promised blocks were
+				// already imported by other means (e.g. fecher):
+				//
+				// R <remote peer>, L <local node>: Both at block 10
+				// R: Mine block 11, and propagate it to L
+				// L: Queue block 11 for import
+				// L: Notice that R's head and TD increased compared to ours, start sync
+				// L: Import of block 11 finishes
+				// L: Sync begins, and finds common ancestor at 11
+				// L: Request new headers up from 11 (R's TD was higher, it must have something)
+				// R: Nothing to give
+				if !gotHeaders && td.Cmp(d.headBlock().Td) > 0 {
+					return errStallingPeer
+				}
+				return nil
+			}
+			gotHeaders = true
+
+			// Otherwise insert all the new headers, aborting in case of junk
+			glog.V(logger.Detail).Infof("%v: inserting %d headers from #%d", p, len(headerPack.headers), from)
+
+			inserts := d.queue.Insert(headerPack.headers)
+			if len(inserts) != len(headerPack.headers) {
+				glog.V(logger.Debug).Infof("%v: stale headers", p)
+				return errBadPeer
+			}
+			// Notify the block fetcher of new headers, but stop if queue is full
+			cont := d.queue.Pending() < maxQueuedHeaders
+			select {
+			case d.processCh <- cont:
+			default:
+			}
+			if !cont {
+				return nil
+			}
+			// Queue not yet full, fetch the next batch
+			from += uint64(len(headerPack.headers))
+			getHeaders(from)
+
+		case <-timeout.C:
+			glog.V(logger.Debug).Infof("%v: header request timed out", p)
+			return errTimeout
+		}
+	}
+}
+
+// fetchBodies iteratively downloads the scheduled block odies, taking any
+// available peers, reserving a chunk of blocks for each, waiting for delivery
+// and also periodically checking for timeouts.
+func (d *Downloader) fetchBodies(from uint64) error {
+	glog.V(logger.Debug).Infof("Downloading block bodies from #%d", from)
+	defer glog.V(logger.Debug).Infof("Block body download terminated")
+
+	// Create a timeout timer for scheduling expiration tasks
+	ticker := time.NewTicker(100 * time.Millisecond)
+	defer ticker.Stop()
+
+	update := make(chan struct{}, 1)
+
+	// Prepare the queue and fetch block bodies until the block header fetcher's done
+	d.queue.Prepare(from)
+	finished := false
+
+	for {
+		select {
+		case <-d.cancelCh:
+			return errCancelBlockFetch
+
+		case <-d.hashCh:
+			// Out of bounds eth/61 hashes received, ignore them
+
+		case <-d.blockCh:
+			// Out of bounds eth/61 blocks received, ignore them
+
+		case bodyPack := <-d.bodyCh:
+			// If the peer was previously banned and failed to deliver it's pack
+			// in a reasonable time frame, ignore it's message.
+			if peer := d.peers.Peer(bodyPack.peerId); peer != nil {
+				// Deliver the received chunk of bodies, and demote in case of errors
+				err := d.queue.Deliver(bodyPack.peerId, bodyPack.transactions, bodyPack.uncles)
+				switch err {
+				case nil:
+					// If no blocks were delivered, demote the peer (need the delivery above)
+					if len(bodyPack.transactions) == 0 || len(bodyPack.uncles) == 0 {
+						peer.Demote()
+						peer.SetIdle()
+						glog.V(logger.Detail).Infof("%s: no block bodies delivered", peer)
+						break
+					}
+					// All was successful, promote the peer and potentially start processing
+					peer.Promote()
+					peer.SetIdle()
+					glog.V(logger.Detail).Infof("%s: delivered %d:%d block bodies", peer, len(bodyPack.transactions), len(bodyPack.uncles))
+					go d.process()
+
+				case errInvalidChain:
+					// The hash chain is invalid (blocks are not ordered properly), abort
+					return err
+
+				case errInvalidBody:
+					// The peer delivered something very bad, drop immediately
+					glog.V(logger.Error).Infof("%s: delivered invalid block, DROP DROP DROP (i.e. implement)!!!", peer)
+
+				case errNoFetchesPending:
+					// Peer probably timed out with its delivery but came through
+					// in the end, demote, but allow to to pull from this peer.
+					peer.Demote()
+					peer.SetIdle()
+					glog.V(logger.Detail).Infof("%s: out of bound delivery", peer)
+
+				case errStaleDelivery:
+					// Delivered something completely else than requested, usually
+					// caused by a timeout and delivery during a new sync cycle.
+					// Don't set it to idle as the original request should still be
+					// in flight.
+					peer.Demote()
+					glog.V(logger.Detail).Infof("%s: stale delivery", peer)
+
+				default:
+					// Peer did something semi-useful, demote but keep it around
+					peer.Demote()
+					peer.SetIdle()
+					glog.V(logger.Detail).Infof("%s: delivery partially failed: %v", peer, err)
+					go d.process()
+				}
+			}
+			// Blocks assembled, try to update the progress
+			select {
+			case update <- struct{}{}:
+			default:
+			}
+
+		case cont := <-d.processCh:
+			// The header fetcher sent a continuation flag, check if it's done
+			if !cont {
+				finished = true
+			}
+			// Headers arrive, try to update the progress
+			select {
+			case update <- struct{}{}:
+			default:
+			}
+
+		case <-ticker.C:
+			// Sanity check update the progress
+			select {
+			case update <- struct{}{}:
+			default:
+			}
+
+		case <-update:
+			// Short circuit if we lost all our peers
+			if d.peers.Len() == 0 {
+				return errNoPeers
+			}
+			// Check for block body request timeouts and demote the responsible peers
+			for _, pid := range d.queue.Expire(bodyHardTTL) {
+				if peer := d.peers.Peer(pid); peer != nil {
+					peer.Demote()
+					glog.V(logger.Detail).Infof("%s: block body delivery timeout", peer)
+				}
+			}
+			// If there's noting more to fetch, wait or terminate
+			if d.queue.Pending() == 0 {
+				if d.queue.InFlight() == 0 && finished {
+					glog.V(logger.Debug).Infof("Block body fetching completed")
+					return nil
+				}
+				break
+			}
+			// Send a download request to all idle peers, until throttled
+			for _, peer := range d.peers.IdlePeers() {
+				// Short circuit if throttling activated
+				if d.queue.Throttle() {
+					break
+				}
+				// Reserve a chunk of hashes for a peer. A nil can mean either that
+				// no more hashes are available, or that the peer is known not to
+				// have them.
+				request := d.queue.Reserve(peer, peer.Capacity())
+				if request == nil {
+					continue
+				}
+				if glog.V(logger.Detail) {
+					glog.Infof("%s: requesting %d block bodies", peer, len(request.Headers))
+				}
+				// Fetch the chunk and make sure any errors return the hashes to the queue
+				if err := peer.Fetch(request); err != nil {
+					glog.V(logger.Error).Infof("%v: fetch failed, rescheduling", peer)
+					d.queue.Cancel(request)
+				}
+			}
+			// Make sure that we have peers available for fetching. If all peers have been tried
+			// and all failed throw an error
+			if !d.queue.Throttle() && d.queue.InFlight() == 0 {
+				return errPeersUnavailable
+			}
+		}
+	}
+}
+
 // process takes blocks from the queue and tries to import them into the chain.
 //
 // The algorithmic flow is as follows:

eth/downloader/downloader_test.go

@@ -155,8 +155,8 @@ func (dl *downloadTester) newPeer(id string, version int, hashes []common.Hash,
 // potentially slow network IO.
 func (dl *downloadTester) newSlowPeer(id string, version int, hashes []common.Hash, blocks map[common.Hash]*types.Block, delay time.Duration) error {
 	err := dl.downloader.RegisterPeer(id, version, hashes[0],
-		dl.peerGetRelHashesFn(id, delay), dl.peerGetAbsHashesFn(id, version, delay), dl.peerGetBlocksFn(id, delay),
+		dl.peerGetRelHashesFn(id, delay), dl.peerGetAbsHashesFn(id, delay), dl.peerGetBlocksFn(id, delay),
-		nil, dl.peerGetAbsHeadersFn(id, version, delay), nil)
+		nil, dl.peerGetAbsHeadersFn(id, delay), dl.peerGetBodiesFn(id, delay))
 	if err == nil {
 		// Assign the owned hashes and blocks to the peer (deep copy)
 		dl.peerHashes[id] = make([]common.Hash, len(hashes))
@@ -209,7 +209,7 @@ func (dl *downloadTester) peerGetRelHashesFn(id string, delay time.Duration) fun
 // peerGetAbsHashesFn constructs a GetHashesFromNumber function associated with
 // a particular peer in the download tester. The returned function can be used to
 // retrieve batches of hashes from the particularly requested peer.
-func (dl *downloadTester) peerGetAbsHashesFn(id string, version int, delay time.Duration) func(uint64, int) error {
+func (dl *downloadTester) peerGetAbsHashesFn(id string, delay time.Duration) func(uint64, int) error {
 	return func(head uint64, count int) error {
 		time.Sleep(delay)
 
@@ -250,7 +250,7 @@ func (dl *downloadTester) peerGetBlocksFn(id string, delay time.Duration) func([
 // peerGetAbsHeadersFn constructs a GetBlockHeaders function based on a numbered
 // origin; associated with a particular peer in the download tester. The returned
 // function can be used to retrieve batches of headers from the particular peer.
-func (dl *downloadTester) peerGetAbsHeadersFn(id string, version int, delay time.Duration) func(uint64, int, int, bool) error {
+func (dl *downloadTester) peerGetAbsHeadersFn(id string, delay time.Duration) func(uint64, int, int, bool) error {
 	return func(origin uint64, amount int, skip int, reverse bool) error {
 		time.Sleep(delay)
 
@@ -259,7 +259,9 @@ func (dl *downloadTester) peerGetAbsHeadersFn(id string, version int, delay time
 		blocks := dl.peerBlocks[id]
 		result := make([]*types.Header, 0, amount)
 		for i := 0; i < amount && len(hashes)-int(origin)-1-i >= 0; i++ {
-			result = append(result, blocks[hashes[len(hashes)-int(origin)-1-i]].Header())
+			if block, ok := blocks[hashes[len(hashes)-int(origin)-1-i]]; ok {
+				result = append(result, block.Header())
+			}
 		}
 		// Delay delivery a bit to allow attacks to unfold
 		go func() {
@@ -270,6 +272,29 @@ func (dl *downloadTester) peerGetAbsHeadersFn(id string, version int, delay time
 	}
 }
 
+// peerGetBodiesFn constructs a getBlockBodies method associated with a particular
+// peer in the download tester. The returned function can be used to retrieve
+// batches of block bodies from the particularly requested peer.
+func (dl *downloadTester) peerGetBodiesFn(id string, delay time.Duration) func([]common.Hash) error {
+	return func(hashes []common.Hash) error {
+		time.Sleep(delay)
+		blocks := dl.peerBlocks[id]
+
+		transactions := make([][]*types.Transaction, 0, len(hashes))
+		uncles := make([][]*types.Header, 0, len(hashes))
+
+		for _, hash := range hashes {
+			if block, ok := blocks[hash]; ok {
+				transactions = append(transactions, block.Transactions())
+				uncles = append(uncles, block.Uncles())
+			}
+		}
+		go dl.downloader.DeliverBodies(id, transactions, uncles)
+
+		return nil
+	}
+}
+
 // Tests that simple synchronization against a canonical chain works correctly.
 // In this test common ancestor lookup should be short circuited and not require
 // binary searching.
@@ -295,7 +320,8 @@ func testCanonicalSynchronisation(t *testing.T, protocol int) {
 
 // Tests that if a large batch of blocks are being downloaded, it is throttled
 // until the cached blocks are retrieved.
-func TestThrottling61(t *testing.T) { testThrottling(t, eth61) }
+func TestThrottling61(t *testing.T) { testThrottling(t, 61) }
+func TestThrottling62(t *testing.T) { testThrottling(t, 62) }
 
 func testThrottling(t *testing.T, protocol int) {
 	// Create a long block chain to download and the tester
@@ -383,7 +409,7 @@ func testForkedSynchronisation(t *testing.T, protocol int) {
 }
 
 // Tests that an inactive downloader will not accept incoming hashes and blocks.
-func TestInactiveDownloader(t *testing.T) {
+func TestInactiveDownloader61(t *testing.T) {
 	tester := newTester()
 
 	// Check that neither hashes nor blocks are accepted
@@ -395,8 +421,22 @@ func TestInactiveDownloader(t *testing.T) {
 	}
 }
 
+// Tests that an inactive downloader will not accept incoming block headers and bodies.
+func TestInactiveDownloader62(t *testing.T) {
+	tester := newTester()
+
+	// Check that neither block headers nor bodies are accepted
+	if err := tester.downloader.DeliverHeaders("bad peer", []*types.Header{}); err != errNoSyncActive {
+		t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
+	}
+	if err := tester.downloader.DeliverBodies("bad peer", [][]*types.Transaction{}, [][]*types.Header{}); err != errNoSyncActive {
+		t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
+	}
+}
+
 // Tests that a canceled download wipes all previously accumulated state.
-func TestCancel61(t *testing.T) { testCancel(t, eth61) }
+func TestCancel61(t *testing.T) { testCancel(t, 61) }
+func TestCancel62(t *testing.T) { testCancel(t, 62) }
 
 func testCancel(t *testing.T, protocol int) {
 	// Create a small enough block chain to download and the tester
@@ -404,6 +444,9 @@ func testCancel(t *testing.T, protocol int) {
 	if targetBlocks >= MaxHashFetch {
 		targetBlocks = MaxHashFetch - 15
 	}
+	if targetBlocks >= MaxHeaderFetch {
+		targetBlocks = MaxHeaderFetch - 15
+	}
 	hashes, blocks := makeChain(targetBlocks, 0, genesis)
 
 	tester := newTester()
@@ -411,23 +454,24 @@ func testCancel(t *testing.T, protocol int) {
 
 	// Make sure canceling works with a pristine downloader
 	tester.downloader.cancel()
-	hashCount, blockCount := tester.downloader.queue.Size()
+	downloading, importing := tester.downloader.queue.Size()
-	if hashCount > 0 || blockCount > 0 {
+	if downloading > 0 || importing > 0 {
-		t.Errorf("block or hash count mismatch: %d hashes, %d blocks, want 0", hashCount, blockCount)
+		t.Errorf("download or import count mismatch: %d downloading, %d importing, want 0", downloading, importing)
 	}
 	// Synchronise with the peer, but cancel afterwards
 	if err := tester.sync("peer", nil); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
 	tester.downloader.cancel()
-	hashCount, blockCount = tester.downloader.queue.Size()
+	downloading, importing = tester.downloader.queue.Size()
-	if hashCount > 0 || blockCount > 0 {
+	if downloading > 0 || importing > 0 {
-		t.Errorf("block or hash count mismatch: %d hashes, %d blocks, want 0", hashCount, blockCount)
+		t.Errorf("download or import count mismatch: %d downloading, %d importing, want 0", downloading, importing)
 	}
 }
 
 // Tests that synchronisation from multiple peers works as intended (multi thread sanity test).
-func TestMultiSynchronisation61(t *testing.T) { testMultiSynchronisation(t, eth61) }
+func TestMultiSynchronisation61(t *testing.T) { testMultiSynchronisation(t, 61) }
+func TestMultiSynchronisation62(t *testing.T) { testMultiSynchronisation(t, 62) }
 
 func testMultiSynchronisation(t *testing.T, protocol int) {
 	// Create various peers with various parts of the chain
@@ -459,16 +503,24 @@ func testMultiSynchronisation(t *testing.T, protocol int) {
 
 // Tests that a peer advertising an high TD doesn't get to stall the downloader
 // afterwards by not sending any useful hashes.
-func TestHighTDStarvationAttack61(t *testing.T) {
+func TestHighTDStarvationAttack61(t *testing.T) { testHighTDStarvationAttack(t, 61) }
+func TestHighTDStarvationAttack62(t *testing.T) { testHighTDStarvationAttack(t, 62) }
+
+func testHighTDStarvationAttack(t *testing.T, protocol int) {
 	tester := newTester()
-	tester.newPeer("attack", eth61, []common.Hash{genesis.Hash()}, nil)
+	hashes, blocks := makeChain(0, 0, genesis)
+
+	tester.newPeer("attack", protocol, []common.Hash{hashes[0]}, blocks)
 	if err := tester.sync("attack", big.NewInt(1000000)); err != errStallingPeer {
 		t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
 	}
 }
 
 // Tests that misbehaving peers are disconnected, whilst behaving ones are not.
-func TestHashAttackerDropping(t *testing.T) {
+func TestBlockHeaderAttackerDropping61(t *testing.T) { testBlockHeaderAttackerDropping(t, 61) }
+func TestBlockHeaderAttackerDropping62(t *testing.T) { testBlockHeaderAttackerDropping(t, 62) }
+
+func testBlockHeaderAttackerDropping(t *testing.T, protocol int) {
 	// Define the disconnection requirement for individual hash fetch errors
 	tests := []struct {
 		result error
@@ -479,7 +531,6 @@ func TestHashAttackerDropping(t *testing.T) {
 		{errUnknownPeer, false},       // Peer is unknown, was already dropped, don't double drop
 		{errBadPeer, true},            // Peer was deemed bad for some reason, drop it
 		{errStallingPeer, true},       // Peer was detected to be stalling, drop it
-		{errBannedHead, true},        // Peer's head hash is a known bad hash, drop it
 		{errNoPeers, false},           // No peers to download from, soft race, no issue
 		{errPendingQueue, false},      // There are blocks still cached, wait to exhaust, no issue
 		{errTimeout, true},            // No hashes received in due time, drop the peer
@@ -487,16 +538,18 @@ func TestHashAttackerDropping(t *testing.T) {
 		{errEmptyHeaderSet, true},     // No headers were returned as a response, drop as it's a dead end
 		{errPeersUnavailable, true},   // Nobody had the advertised blocks, drop the advertiser
 		{errInvalidChain, true},       // Hash chain was detected as invalid, definitely drop
-		{errCrossCheckFailed, true},  // Hash-origin failed to pass a block cross check, drop
+		{errInvalidBody, false},       // A bad peer was detected, but not the sync origin
 		{errCancelHashFetch, false},   // Synchronisation was canceled, origin may be innocent, don't drop
 		{errCancelBlockFetch, false},  // Synchronisation was canceled, origin may be innocent, don't drop
+		{errCancelHeaderFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
+		{errCancelBodyFetch, false},   // Synchronisation was canceled, origin may be innocent, don't drop
 	}
 	// Run the tests and check disconnection status
 	tester := newTester()
 	for i, tt := range tests {
 		// Register a new peer and ensure it's presence
 		id := fmt.Sprintf("test %d", i)
-		if err := tester.newPeer(id, eth61, []common.Hash{genesis.Hash()}, nil); err != nil {
+		if err := tester.newPeer(id, protocol, []common.Hash{genesis.Hash()}, nil); err != nil {
 			t.Fatalf("test %d: failed to register new peer: %v", i, err)
 		}
 		if _, ok := tester.peerHashes[id]; !ok {
@@ -513,7 +566,10 @@ func TestHashAttackerDropping(t *testing.T) {
 }
 
 // Tests that feeding bad blocks will result in a peer drop.
-func TestBlockAttackerDropping(t *testing.T) {
+func TestBlockBodyAttackerDropping61(t *testing.T) { testBlockBodyAttackerDropping(t, 61) }
+func TestBlockBodyAttackerDropping62(t *testing.T) { testBlockBodyAttackerDropping(t, 62) }
+
+func testBlockBodyAttackerDropping(t *testing.T, protocol int) {
 	// Define the disconnection requirement for individual block import errors
 	tests := []struct {
 		failure bool
@@ -528,7 +584,7 @@ func TestBlockAttackerDropping(t *testing.T) {
 	for i, tt := range tests {
 		// Register a new peer and ensure it's presence
 		id := fmt.Sprintf("test %d", i)
-		if err := tester.newPeer(id, eth61, []common.Hash{common.Hash{}}, nil); err != nil {
+		if err := tester.newPeer(id, protocol, []common.Hash{common.Hash{}}, nil); err != nil {
 			t.Fatalf("test %d: failed to register new peer: %v", i, err)
 		}
 		if _, ok := tester.peerHashes[id]; !ok {

eth/downloader/peer.go

@@ -101,8 +101,8 @@ func (p *peer) Reset() {
 	p.ignored.Clear()
 }
 
-// Fetch sends a block retrieval request to the remote peer.
+// Fetch61 sends a block retrieval request to the remote peer.
-func (p *peer) Fetch(request *fetchRequest) error {
+func (p *peer) Fetch61(request *fetchRequest) error {
 	// Short circuit if the peer is already fetching
 	if !atomic.CompareAndSwapInt32(&p.idle, 0, 1) {
 		return errAlreadyFetching
@@ -119,10 +119,28 @@ func (p *peer) Fetch(request *fetchRequest) error {
 	return nil
 }
 
-// SetIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// Fetch sends a block body retrieval request to the remote peer.
+func (p *peer) Fetch(request *fetchRequest) error {
+	// Short circuit if the peer is already fetching
+	if !atomic.CompareAndSwapInt32(&p.idle, 0, 1) {
+		return errAlreadyFetching
+	}
+	p.started = time.Now()
+
+	// Convert the header set to a retrievable slice
+	hashes := make([]common.Hash, 0, len(request.Headers))
+	for _, header := range request.Headers {
+		hashes = append(hashes, header.Hash())
+	}
+	go p.getBlockBodies(hashes)
+
+	return nil
+}
+
+// SetIdle61 sets the peer to idle, allowing it to execute new retrieval requests.
 // Its block retrieval allowance will also be updated either up- or downwards,
 // depending on whether the previous fetch completed in time or not.
-func (p *peer) SetIdle() {
+func (p *peer) SetIdle61() {
 	// Update the peer's download allowance based on previous performance
 	scale := 2.0
 	if time.Since(p.started) > blockSoftTTL {
@@ -149,6 +167,36 @@ func (p *peer) SetIdle() {
 	atomic.StoreInt32(&p.idle, 0)
 }
 
+// SetIdle sets the peer to idle, allowing it to execute new retrieval requests.
+// Its block body retrieval allowance will also be updated either up- or downwards,
+// depending on whether the previous fetch completed in time or not.
+func (p *peer) SetIdle() {
+	// Update the peer's download allowance based on previous performance
+	scale := 2.0
+	if time.Since(p.started) > bodySoftTTL {
+		scale = 0.5
+		if time.Since(p.started) > bodyHardTTL {
+			scale = 1 / float64(MaxBodyFetch) // reduces capacity to 1
+		}
+	}
+	for {
+		// Calculate the new download bandwidth allowance
+		prev := atomic.LoadInt32(&p.capacity)
+		next := int32(math.Max(1, math.Min(float64(MaxBodyFetch), float64(prev)*scale)))
+
+		// Try to update the old value
+		if atomic.CompareAndSwapInt32(&p.capacity, prev, next) {
+			// If we're having problems at 1 capacity, try to find better peers
+			if next == 1 {
+				p.Demote()
+			}
+			break
+		}
+	}
+	// Set the peer to idle to allow further block requests
+	atomic.StoreInt32(&p.idle, 0)
+}
+
 // Capacity retrieves the peers block download allowance based on its previously
 // discovered bandwidth capacity.
 func (p *peer) Capacity() int {

eth/downloader/queue.go

@@ -44,15 +44,19 @@ var (
 // fetchRequest is a currently running block retrieval operation.
 type fetchRequest struct {
 	Peer    *peer               // Peer to which the request was sent
-	Hashes map[common.Hash]int // Requested hashes with their insertion index (priority)
+	Hashes  map[common.Hash]int // [eth/61] Requested hashes with their insertion index (priority)
+	Headers []*types.Header     // [eth/62] Requested headers, sorted by request order
 	Time    time.Time           // Time when the request was made
 }
 
 // queue represents hashes that are either need fetching or are being fetched
 type queue struct {
-	hashPool    map[common.Hash]int // Pending hashes, mapping to their insertion index (priority)
+	hashPool    map[common.Hash]int // [eth/61] Pending hashes, mapping to their insertion index (priority)
-	hashQueue   *prque.Prque        // Priority queue of the block hashes to fetch
+	hashQueue   *prque.Prque        // [eth/61] Priority queue of the block hashes to fetch
-	hashCounter int                 // Counter indexing the added hashes to ensure retrieval order
+	hashCounter int                 // [eth/61] Counter indexing the added hashes to ensure retrieval order
+
+	headerPool  map[common.Hash]*types.Header // [eth/62] Pending headers, mapping from their hashes
+	headerQueue *prque.Prque                  // [eth/62] Priority queue of the headers to fetch the bodies for
 
 	pendPool map[string]*fetchRequest // Currently pending block retrieval operations
 
@@ -68,6 +72,8 @@ func newQueue() *queue {
 	return &queue{
 		hashPool:    make(map[common.Hash]int),
 		hashQueue:   prque.New(),
+		headerPool:  make(map[common.Hash]*types.Header),
+		headerQueue: prque.New(),
 		pendPool:    make(map[string]*fetchRequest),
 		blockPool:   make(map[common.Hash]uint64),
 		blockCache:  make([]*Block, blockCacheLimit),
@@ -83,6 +89,9 @@ func (q *queue) Reset() {
 	q.hashQueue.Reset()
 	q.hashCounter = 0
 
+	q.headerPool = make(map[common.Hash]*types.Header)
+	q.headerQueue.Reset()
+
 	q.pendPool = make(map[string]*fetchRequest)
 
 	q.blockPool = make(map[common.Hash]uint64)
@@ -90,21 +99,21 @@ func (q *queue) Reset() {
 	q.blockCache = make([]*Block, blockCacheLimit)
 }
 
-// Size retrieves the number of hashes in the queue, returning separately for
+// Size retrieves the number of blocks in the queue, returning separately for
 // pending and already downloaded.
 func (q *queue) Size() (int, int) {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	return len(q.hashPool), len(q.blockPool)
+	return len(q.hashPool) + len(q.headerPool), len(q.blockPool)
 }
 
-// Pending retrieves the number of hashes pending for retrieval.
+// Pending retrieves the number of blocks pending for retrieval.
 func (q *queue) Pending() int {
 	q.lock.RLock()
 	defer q.lock.RUnlock()
 
-	return q.hashQueue.Size()
+	return q.hashQueue.Size() + q.headerQueue.Size()
 }
 
 // InFlight retrieves the number of fetch requests currently in flight.
@@ -124,7 +133,7 @@ func (q *queue) Throttle() bool {
 	// Calculate the currently in-flight block requests
 	pending := 0
 	for _, request := range q.pendPool {
-		pending += len(request.Hashes)
+		pending += len(request.Hashes) + len(request.Headers)
 	}
 	// Throttle if more blocks are in-flight than free space in the cache
 	return pending >= len(q.blockCache)-len(q.blockPool)
@@ -138,15 +147,18 @@ func (q *queue) Has(hash common.Hash) bool {
 	if _, ok := q.hashPool[hash]; ok {
 		return true
 	}
+	if _, ok := q.headerPool[hash]; ok {
+		return true
+	}
 	if _, ok := q.blockPool[hash]; ok {
 		return true
 	}
 	return false
 }
 
-// Insert adds a set of hashes for the download queue for scheduling, returning
+// Insert61 adds a set of hashes for the download queue for scheduling, returning
 // the new hashes encountered.
-func (q *queue) Insert(hashes []common.Hash, fifo bool) []common.Hash {
+func (q *queue) Insert61(hashes []common.Hash, fifo bool) []common.Hash {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -172,6 +184,29 @@ func (q *queue) Insert(hashes []common.Hash, fifo bool) []common.Hash {
 	return inserts
 }
 
+// Insert adds a set of headers for the download queue for scheduling, returning
+// the new headers encountered.
+func (q *queue) Insert(headers []*types.Header) []*types.Header {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	// Insert all the headers prioritized by the contained block number
+	inserts := make([]*types.Header, 0, len(headers))
+	for _, header := range headers {
+		// Make sure no duplicate requests are executed
+		hash := header.Hash()
+		if _, ok := q.headerPool[hash]; ok {
+			glog.V(logger.Warn).Infof("Header %x already scheduled", hash)
+			continue
+		}
+		// Queue the header for body retrieval
+		inserts = append(inserts, header)
+		q.headerPool[hash] = header
+		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+	}
+	return inserts
+}
+
 // GetHeadBlock retrieves the first block from the cache, or nil if it hasn't
 // been downloaded yet (or simply non existent).
 func (q *queue) GetHeadBlock() *Block {
@@ -227,9 +262,9 @@ func (q *queue) TakeBlocks() []*Block {
 	return blocks
 }
 
-// Reserve reserves a set of hashes for the given peer, skipping any previously
+// Reserve61 reserves a set of hashes for the given peer, skipping any previously
 // failed download.
-func (q *queue) Reserve(p *peer, count int) *fetchRequest {
+func (q *queue) Reserve61(p *peer, count int) *fetchRequest {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -276,6 +311,55 @@ func (q *queue) Reserve(p *peer, count int) *fetchRequest {
 	return request
 }
 
+// Reserve reserves a set of headers for the given peer, skipping any previously
+// failed download.
+func (q *queue) Reserve(p *peer, count int) *fetchRequest {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	// Short circuit if the pool has been depleted, or if the peer's already
+	// downloading something (sanity check not to corrupt state)
+	if q.headerQueue.Empty() {
+		return nil
+	}
+	if _, ok := q.pendPool[p.id]; ok {
+		return nil
+	}
+	// Calculate an upper limit on the bodies we might fetch (i.e. throttling)
+	space := len(q.blockCache) - len(q.blockPool)
+	for _, request := range q.pendPool {
+		space -= len(request.Headers)
+	}
+	// Retrieve a batch of headers, skipping previously failed ones
+	send := make([]*types.Header, 0, count)
+	skip := make([]*types.Header, 0)
+
+	for proc := 0; proc < space && len(send) < count && !q.headerQueue.Empty(); proc++ {
+		header := q.headerQueue.PopItem().(*types.Header)
+		if p.ignored.Has(header.Hash()) {
+			skip = append(skip, header)
+		} else {
+			send = append(send, header)
+		}
+	}
+	// Merge all the skipped headers back
+	for _, header := range skip {
+		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+	}
+	// Assemble and return the block download request
+	if len(send) == 0 {
+		return nil
+	}
+	request := &fetchRequest{
+		Peer:    p,
+		Headers: send,
+		Time:    time.Now(),
+	}
+	q.pendPool[p.id] = request
+
+	return request
+}
+
 // Cancel aborts a fetch request, returning all pending hashes to the queue.
 func (q *queue) Cancel(request *fetchRequest) {
 	q.lock.Lock()
@@ -284,6 +368,9 @@ func (q *queue) Cancel(request *fetchRequest) {
 	for hash, index := range request.Hashes {
 		q.hashQueue.Push(hash, float32(index))
 	}
+	for _, header := range request.Headers {
+		q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+	}
 	delete(q.pendPool, request.Peer.id)
 }
 
@@ -310,8 +397,8 @@ func (q *queue) Expire(timeout time.Duration) []string {
 	return peers
 }
 
-// Deliver injects a block retrieval response into the download queue.
+// Deliver61 injects a block retrieval response into the download queue.
-func (q *queue) Deliver(id string, blocks []*types.Block) (err error) {
+func (q *queue) Deliver61(id string, blocks []*types.Block) (err error) {
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
@@ -365,6 +452,67 @@ func (q *queue) Deliver(id string, blocks []*types.Block) (err error) {
 	return nil
 }
 
+// Deliver injects a block body retrieval response into the download queue.
+func (q *queue) Deliver(id string, transactions [][]*types.Transaction, uncles [][]*types.Header) (err error) {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	// Short circuit if the block bodies were never requested
+	request := q.pendPool[id]
+	if request == nil {
+		return errNoFetchesPending
+	}
+	delete(q.pendPool, id)
+
+	// If no block bodies were retrieved, mark them as unavailable for the origin peer
+	if len(transactions) == 0 || len(uncles) == 0 {
+		for hash, _ := range request.Headers {
+			request.Peer.ignored.Add(hash)
+		}
+	}
+	// Assemble each of the block bodies with their headers and queue for processing
+	errs := make([]error, 0)
+	for i, header := range request.Headers {
+		// Short circuit block assembly if no more bodies are found
+		if i >= len(transactions) || i >= len(uncles) {
+			break
+		}
+		// Reconstruct the next block if contents match up
+		if types.DeriveSha(types.Transactions(transactions[i])) != header.TxHash || types.CalcUncleHash(uncles[i]) != header.UncleHash {
+			return errInvalidBody
+		}
+		block := types.NewBlockWithHeader(header).WithBody(transactions[i], uncles[i])
+
+		// If a requested block falls out of the range, the hash chain is invalid
+		index := int(int64(block.NumberU64()) - int64(q.blockOffset))
+		if index >= len(q.blockCache) || index < 0 {
+			return errInvalidChain
+		}
+		// Otherwise merge the block and mark the hash done
+		q.blockCache[index] = &Block{
+			RawBlock:   block,
+			OriginPeer: id,
+		}
+		request.Headers[i] = nil
+		delete(q.headerPool, header.Hash())
+		q.blockPool[header.Hash()] = block.NumberU64()
+	}
+	// Return all failed or missing fetches to the queue
+	for _, header := range request.Headers {
+		if header != nil {
+			q.headerQueue.Push(header, -float32(header.Number.Uint64()))
+		}
+	}
+	// If none of the blocks were good, it's a stale delivery
+	if len(errs) != 0 {
+		if len(errs) == len(request.Headers) {
+			return errStaleDelivery
+		}
+		return fmt.Errorf("multiple failures: %v", errs)
+	}
+	return nil
+}
+
 // Prepare configures the block cache offset to allow accepting inbound blocks.
 func (q *queue) Prepare(offset uint64) {
 	q.lock.Lock()

eth/handler.go

@@ -203,7 +203,7 @@ func (pm *ProtocolManager) handle(p *peer) error {
 	// Register the peer in the downloader. If the downloader considers it banned, we disconnect
 	if err := pm.downloader.RegisterPeer(p.id, p.version, p.Head(),
 		p.RequestHashes, p.RequestHashesFromNumber, p.RequestBlocks,
-		p.RequestHeadersByHash, p.RequestHeadersByNumber, nil); err != nil {
+		p.RequestHeadersByHash, p.RequestHeadersByNumber, p.RequestBodies); err != nil {
 		return err
 	}
 	// Propagate existing transactions. new transactions appearing
@@ -401,7 +401,6 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				query.Origin.Number += (query.Skip + 1)
 			}
 		}
-		fmt.Println("Sending headers", len(headers))
 		return p.SendBlockHeaders(headers)
 
 	case p.version >= eth62 && msg.Code == BlockHeadersMsg:
@@ -416,6 +415,25 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			glog.V(logger.Debug).Infoln(err)
 		}
 
+	case p.version >= eth62 && msg.Code == BlockBodiesMsg:
+		// A batch of block bodies arrived to one of our previous requests
+		var request blockBodiesData
+		if err := msg.Decode(&request); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Deliver them all to the downloader for queuing
+		trasactions := make([][]*types.Transaction, len(request))
+		uncles := make([][]*types.Header, len(request))
+
+		for i, body := range request {
+			trasactions[i] = body.Transactions
+			uncles[i] = body.Uncles
+		}
+		err := pm.downloader.DeliverBodies(p.id, trasactions, uncles)
+		if err != nil {
+			glog.V(logger.Debug).Infoln(err)
+		}
+
 	case p.version >= eth62 && msg.Code == GetBlockBodiesMsg:
 		// Decode the retrieval message
 		msgStream := rlp.NewStream(msg.Payload, uint64(msg.Size))
@@ -625,7 +643,11 @@ func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
 	// Otherwise if the block is indeed in out own chain, announce it
 	if pm.chainman.HasBlock(hash) {
 		for _, peer := range peers {
-			peer.SendNewBlockHashes([]common.Hash{hash})
+			if peer.version < eth62 {
+				peer.SendNewBlockHashes61([]common.Hash{hash})
+			} else {
+				peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
+			}
 		}
 		glog.V(logger.Detail).Infof("announced block %x to %d peers in %v", hash[:4], len(peers), time.Since(block.ReceivedAt))
 	}

eth/peer.go

@@ -145,15 +145,29 @@ func (p *peer) SendBlocks(blocks []*types.Block) error {
 	return p2p.Send(p.rw, BlocksMsg, blocks)
 }
 
-// SendNewBlockHashes announces the availability of a number of blocks through
+// SendNewBlockHashes61 announces the availability of a number of blocks through
 // a hash notification.
-func (p *peer) SendNewBlockHashes(hashes []common.Hash) error {
+func (p *peer) SendNewBlockHashes61(hashes []common.Hash) error {
 	for _, hash := range hashes {
 		p.knownBlocks.Add(hash)
 	}
 	return p2p.Send(p.rw, NewBlockHashesMsg, hashes)
 }
 
+// SendNewBlockHashes announces the availability of a number of blocks through
+// a hash notification.
+func (p *peer) SendNewBlockHashes(hashes []common.Hash, numbers []uint64) error {
+	for _, hash := range hashes {
+		p.knownBlocks.Add(hash)
+	}
+	request := make(newBlockHashesData, len(hashes))
+	for i := 0; i < len(hashes); i++ {
+		request[i].Hash = hashes[i]
+		request[i].Number = numbers[i]
+	}
+	return p2p.Send(p.rw, NewBlockHashesMsg, request)
+}
+
 // SendNewBlock propagates an entire block to a remote peer.
 func (p *peer) SendNewBlock(block *types.Block, td *big.Int) error {
 	p.knownBlocks.Add(block.Hash())
@@ -205,17 +219,24 @@ func (p *peer) RequestBlocks(hashes []common.Hash) error {
 // RequestHeadersByHash fetches a batch of blocks' headers corresponding to the
 // specified header query, based on the hash of an origin block.
 func (p *peer) RequestHeadersByHash(origin common.Hash, amount int, skip int, reverse bool) error {
-	glog.V(logger.Debug).Infof("%v fetching %d headers from %x, skipping %d (reverse = )", p, amount, origin[:4], skip, reverse)
+	glog.V(logger.Debug).Infof("%v fetching %d headers from %x, skipping %d (reverse = %v)", p, amount, origin[:4], skip, reverse)
 	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
 }
 
 // RequestHeadersByNumber fetches a batch of blocks' headers corresponding to the
 // specified header query, based on the number of an origin block.
 func (p *peer) RequestHeadersByNumber(origin uint64, amount int, skip int, reverse bool) error {
-	glog.V(logger.Debug).Infof("%v fetching %d headers from #%d, skipping %d (reverse = )", p, amount, origin, skip, reverse)
+	glog.V(logger.Debug).Infof("%v fetching %d headers from #%d, skipping %d (reverse = %v)", p, amount, origin, skip, reverse)
 	return p2p.Send(p.rw, GetBlockHeadersMsg, &getBlockHeadersData{Origin: hashOrNumber{Number: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
 }
 
+// RequestBodies fetches a batch of blocks' bodies corresponding to the hashes
+// specified.
+func (p *peer) RequestBodies(hashes []common.Hash) error {
+	glog.V(logger.Debug).Infof("%v fetching %d block bodies", p, len(hashes))
+	return p2p.Send(p.rw, GetBlockBodiesMsg, hashes)
+}
+
 // RequestNodeData fetches a batch of arbitrary data from a node's known state
 // data, corresponding to the specified hashes.
 func (p *peer) RequestNodeData(hashes []common.Hash) error {