eth, eth/downloader: pass the eth protocol version through

eth/downloader/downloader.go

@@ -175,7 +175,7 @@ func (d *Downloader) Synchronising() bool {
 
 // RegisterPeer injects a new download peer into the set of block source to be
 // used for fetching hashes and blocks from.
-func (d *Downloader) RegisterPeer(id string, head common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) error {
+func (d *Downloader) RegisterPeer(id string, version int, head common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) 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)
@@ -183,7 +183,7 @@ func (d *Downloader) RegisterPeer(id string, head common.Hash, getHashes hashFet
 	}
 	// Otherwise try to construct and register the peer
 	glog.V(logger.Detail).Infoln("Registering peer", id)
-	if err := d.peers.Register(newPeer(id, head, getHashes, getBlocks)); err != nil {
+	if err := d.peers.Register(newPeer(id, version, head, getHashes, getBlocks)); err != nil {
 		glog.V(logger.Error).Infoln("Register failed:", err)
 		return err
 	}

eth/downloader/downloader_test.go

@@ -16,6 +16,11 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 )
 
+const (
+	eth60 = 60
+	eth61 = 61
+)
+
 var (
 	testdb, _ = ethdb.NewMemDatabase()
 	genesis   = core.GenesisBlockForTesting(testdb, common.Address{}, big.NewInt(0))
@@ -112,15 +117,15 @@ func (dl *downloadTester) insertChain(blocks types.Blocks) (int, error) {
 }
 
 // newPeer registers a new block download source into the downloader.
-func (dl *downloadTester) newPeer(id string, hashes []common.Hash, blocks map[common.Hash]*types.Block) error {
+func (dl *downloadTester) newPeer(id string, version int, hashes []common.Hash, blocks map[common.Hash]*types.Block) error {
-	return dl.newSlowPeer(id, hashes, blocks, 0)
+	return dl.newSlowPeer(id, version, hashes, blocks, 0)
 }
 
 // newSlowPeer registers a new block download source into the downloader, with a
 // specific delay time on processing the network packets sent to it, simulating
 // potentially slow network IO.
-func (dl *downloadTester) newSlowPeer(id string, hashes []common.Hash, blocks map[common.Hash]*types.Block, delay time.Duration) error {
+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, hashes[0], dl.peerGetHashesFn(id, delay), dl.peerGetBlocksFn(id, delay))
+	err := dl.downloader.RegisterPeer(id, version, hashes[0], dl.peerGetHashesFn(id, delay), dl.peerGetBlocksFn(id, delay))
 	if err == nil {
 		// Assign the owned hashes and blocks to the peer (deep copy)
 		dl.peerHashes[id] = make([]common.Hash, len(hashes))
@@ -201,7 +206,7 @@ func TestSynchronisation(t *testing.T) {
 	hashes, blocks := makeChain(targetBlocks, 0, genesis)
 
 	tester := newTester()
-	tester.newPeer("peer", hashes, blocks)
+	tester.newPeer("peer", eth60, hashes, blocks)
 
 	// Synchronise with the peer and make sure all blocks were retrieved
 	if err := tester.sync("peer"); err != nil {
@@ -232,7 +237,7 @@ func TestCancel(t *testing.T) {
 	hashes, blocks := makeChain(targetBlocks, 0, genesis)
 
 	tester := newTester()
-	tester.newPeer("peer", hashes, blocks)
+	tester.newPeer("peer", eth60, hashes, blocks)
 
 	// Make sure canceling works with a pristine downloader
 	tester.downloader.cancel()
@@ -259,7 +264,7 @@ func TestThrottling(t *testing.T) {
 	hashes, blocks := makeChain(targetBlocks, 0, genesis)
 
 	tester := newTester()
-	tester.newPeer("peer", hashes, blocks)
+	tester.newPeer("peer", eth60, hashes, blocks)
 
 	// Wrap the importer to allow stepping
 	done := make(chan int)
@@ -317,7 +322,7 @@ func TestMultiSynchronisation(t *testing.T) {
 	tester := newTester()
 	for i := 0; i < targetPeers; i++ {
 		id := fmt.Sprintf("peer #%d", i)
-		tester.newPeer(id, hashes[i*blockCacheLimit:], blocks)
+		tester.newPeer(id, eth60, hashes[i*blockCacheLimit:], blocks)
 	}
 	// Synchronise with the middle peer and make sure half of the blocks were retrieved
 	id := fmt.Sprintf("peer #%d", targetPeers/2)
@@ -347,8 +352,8 @@ func TestSlowSynchronisation(t *testing.T) {
 	targetIODelay := time.Second
 	hashes, blocks := makeChain(targetBlocks, 0, genesis)
 
-	tester.newSlowPeer("fast", hashes, blocks, 0)
+	tester.newSlowPeer("fast", eth60, hashes, blocks, 0)
-	tester.newSlowPeer("slow", hashes, blocks, targetIODelay)
+	tester.newSlowPeer("slow", eth60, hashes, blocks, targetIODelay)
 
 	// Try to sync with the peers (pull hashes from fast)
 	start := time.Now()
@@ -370,13 +375,14 @@ func TestSlowSynchronisation(t *testing.T) {
 func TestNonExistingParentAttack(t *testing.T) {
 	tester := newTester()
 
+	// Forge a single-link chain with a forged header
 	hashes, blocks := makeChain(1, 0, genesis)
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
 
 	wrongblock := types.NewBlock(&types.Header{}, nil, nil, nil)
 	wrongblock.Td = blocks[hashes[0]].Td
 	hashes, blocks = makeChain(1, 0, wrongblock)
-	tester.newPeer("attack", hashes, blocks)
+	tester.newPeer("attack", eth60, hashes, blocks)
 
 	// Try and sync with the malicious node and check that it fails
 	if err := tester.sync("attack"); err == nil {
@@ -401,8 +407,8 @@ func TestRepeatingHashAttack(t *testing.T) { // TODO: Is this thing valid??
 
 	// Create a valid chain, but drop the last link
 	hashes, blocks := makeChain(blockCacheLimit, 0, genesis)
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
-	tester.newPeer("attack", hashes[:len(hashes)-1], blocks)
+	tester.newPeer("attack", eth60, hashes[:len(hashes)-1], blocks)
 
 	// Try and sync with the malicious node
 	errc := make(chan error)
@@ -431,10 +437,10 @@ func TestNonExistingBlockAttack(t *testing.T) {
 
 	// Create a valid chain, but forge the last link
 	hashes, blocks := makeChain(blockCacheLimit, 0, genesis)
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
 
 	hashes[len(hashes)/2] = common.Hash{}
-	tester.newPeer("attack", hashes, blocks)
+	tester.newPeer("attack", eth60, hashes, blocks)
 
 	// Try and sync with the malicious node and check that it fails
 	if err := tester.sync("attack"); err != errPeersUnavailable {
@@ -453,7 +459,7 @@ func TestInvalidHashOrderAttack(t *testing.T) {
 
 	// Create a valid long chain, but reverse some hashes within
 	hashes, blocks := makeChain(4*blockCacheLimit, 0, genesis)
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
 
 	chunk1 := make([]common.Hash, blockCacheLimit)
 	chunk2 := make([]common.Hash, blockCacheLimit)
@@ -462,7 +468,7 @@ func TestInvalidHashOrderAttack(t *testing.T) {
 
 	copy(hashes[2*blockCacheLimit:], chunk1)
 	copy(hashes[blockCacheLimit:], chunk2)
-	tester.newPeer("attack", hashes, blocks)
+	tester.newPeer("attack", eth60, hashes, blocks)
 
 	// Try and sync with the malicious node and check that it fails
 	if err := tester.sync("attack"); err != errInvalidChain {
@@ -489,8 +495,8 @@ func TestMadeupHashChainAttack(t *testing.T) {
 		rand.Read(randomHashes[i][:])
 	}
 
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
-	tester.newPeer("attack", randomHashes, nil)
+	tester.newPeer("attack", eth60, randomHashes, nil)
 
 	// Try and sync with the malicious node and check that it fails
 	if err := tester.sync("attack"); err != errCrossCheckFailed {
@@ -517,7 +523,7 @@ func TestMadeupHashChainDrippingAttack(t *testing.T) {
 
 	// Try and sync with the attacker, one hash at a time
 	tester.maxHashFetch = 1
-	tester.newPeer("attack", randomHashes, nil)
+	tester.newPeer("attack", eth60, randomHashes, nil)
 	if err := tester.sync("attack"); err != errStallingPeer {
 		t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
 	}
@@ -540,7 +546,7 @@ func TestMadeupBlockChainAttack(t *testing.T) {
 	}
 	// Try and sync with the malicious node and check that it fails
 	tester := newTester()
-	tester.newPeer("attack", gapped, blocks)
+	tester.newPeer("attack", eth60, gapped, blocks)
 	if err := tester.sync("attack"); err != errCrossCheckFailed {
 		t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errCrossCheckFailed)
 	}
@@ -548,13 +554,13 @@ func TestMadeupBlockChainAttack(t *testing.T) {
 	blockSoftTTL = defaultBlockTTL
 	crossCheckCycle = defaultCrossCheckCycle
 
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
 	if err := tester.sync("valid"); err != nil {
 		t.Fatalf("failed to synchronise blocks: %v", err)
 	}
 }
 
-// tests that if one/multiple malicious peers try to feed a banned blockchain to
+// Tests that if one/multiple malicious peers try to feed a banned blockchain to
 // the downloader, it will not keep refetching the same chain indefinitely, but
 // gradually block pieces of it, until its head is also blocked.
 func TestBannedChainStarvationAttack(t *testing.T) {
@@ -565,8 +571,8 @@ func TestBannedChainStarvationAttack(t *testing.T) {
 	// Create the tester and ban the selected hash.
 	tester := newTester()
 	tester.downloader.banned.Add(forkHashes[fork-1])
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
-	tester.newPeer("attack", forkHashes, forkBlocks)
+	tester.newPeer("attack", eth60, forkHashes, forkBlocks)
 
 	// Iteratively try to sync, and verify that the banned hash list grows until
 	// the head of the invalid chain is blocked too.
@@ -586,7 +592,7 @@ func TestBannedChainStarvationAttack(t *testing.T) {
 		banned = bans
 	}
 	// Check that after banning an entire chain, bad peers get dropped
-	if err := tester.newPeer("new attacker", forkHashes, forkBlocks); err != errBannedHead {
+	if err := tester.newPeer("new attacker", eth60, forkHashes, forkBlocks); err != errBannedHead {
 		t.Fatalf("peer registration mismatch: have %v, want %v", err, errBannedHead)
 	}
 	if peer := tester.downloader.peers.Peer("new attacker"); peer != nil {
@@ -618,8 +624,8 @@ func TestBannedChainMemoryExhaustionAttack(t *testing.T) {
 	MaxBlockFetch = 4
 	maxBannedHashes = 256
 
-	tester.newPeer("valid", hashes, blocks)
+	tester.newPeer("valid", eth60, hashes, blocks)
-	tester.newPeer("attack", forkHashes, forkBlocks)
+	tester.newPeer("attack", eth60, forkHashes, forkBlocks)
 
 	// Iteratively try to sync, and verify that the banned hash list grows until
 	// the head of the invalid chain is blocked too.
@@ -664,7 +670,7 @@ func TestOverlappingDeliveryAttack(t *testing.T) {
 
 	// Register an attacker that always returns non-requested blocks too
 	tester := newTester()
-	tester.newPeer("attack", hashes, blocks)
+	tester.newPeer("attack", eth60, hashes, blocks)
 
 	rawGetBlocks := tester.downloader.peers.Peer("attack").getBlocks
 	tester.downloader.peers.Peer("attack").getBlocks = func(request []common.Hash) error {
@@ -712,7 +718,7 @@ func TestHashAttackerDropping(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, []common.Hash{genesis.Hash()}, nil); err != nil {
+		if err := tester.newPeer(id, eth60, []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 {
@@ -744,7 +750,7 @@ 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, []common.Hash{common.Hash{}}, nil); err != nil {
+		if err := tester.newPeer(id, eth60, []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

@@ -39,11 +39,13 @@ type peer struct {
 
 	getHashes hashFetcherFn  // Method to retrieve a batch of hashes (mockable for testing)
 	getBlocks blockFetcherFn // Method to retrieve a batch of blocks (mockable for testing)
+
+	version int // Eth protocol version number to switch strategies
 }
 
 // newPeer create a new downloader peer, with specific hash and block retrieval
 // mechanisms.
-func newPeer(id string, head common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) *peer {
+func newPeer(id string, version int, head common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) *peer {
 	return &peer{
 		id:        id,
 		head:      head,
@@ -51,6 +53,7 @@ func newPeer(id string, head common.Hash, getHashes hashFetcherFn, getBlocks blo
 		getHashes: getHashes,
 		getBlocks: getBlocks,
 		ignored:   set.New(),
+		version:   version,
 	}
 }
 

eth/handler.go

@@ -181,7 +181,7 @@ func (pm *ProtocolManager) handle(p *peer) error {
 	defer pm.removePeer(p.id)
 
 	// Register the peer in the downloader. If the downloader considers it banned, we disconnect
-	if err := pm.downloader.RegisterPeer(p.id, p.Head(), p.RequestHashes, p.RequestBlocks); err != nil {
+	if err := pm.downloader.RegisterPeer(p.id, p.version, p.Head(), p.RequestHashes, p.RequestBlocks); err != nil {
 		return err
 	}
 	// Propagate existing transactions. new transactions appearing