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Merge pull request #1544 from karalabe/fix-stall-detector

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eth, eth/downloader: don't report stall if fetcher filled the block
This commit is contained in:
Jeffrey Wilcke 2015-07-29 06:11:43 -07:00
commit e7f4232b10
3 changed files with 65 additions and 43 deletions
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32
eth/downloader/downloader.go
View File

@ -21,6 +21,7 @@ import (
"bytes"
"errors"
"math"
"math/big"
"math/rand"
"sync"
"sync/atomic"
@ -232,10 +233,10 @@ func (d *Downloader) UnregisterPeer(id string) error {
// Synchronise tries to sync up our local block chain with a remote peer, both
// adding various sanity checks as well as wrapping it with various log entries.
func (d *Downloader) Synchronise(id string, head common.Hash) {
glog.V(logger.Detail).Infof("Attempting synchronisation: %v, 0x%x", id, head)
func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int) {
glog.V(logger.Detail).Infof("Attempting synchronisation: %v, head 0x%x, TD %v", id, head[:4], td)
switch err := d.synchronise(id, head); err {
switch err := d.synchronise(id, head, td); err {
case nil:
glog.V(logger.Detail).Infof("Synchronisation completed")
@ -257,7 +258,7 @@ func (d *Downloader) Synchronise(id string, head common.Hash) {
// synchronise will select the peer and use it for synchronising. If an empty string is given
// it will use the best peer possible and synchronize if it's TD is higher than our own. If any of the
// checks fail an error will be returned. This method is synchronous
func (d *Downloader) synchronise(id string, hash common.Hash) error {
func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int) error {
// Mock out the synchonisation if testing
if d.synchroniseMock != nil {
return d.synchroniseMock(id, hash)
@ -295,7 +296,7 @@ func (d *Downloader) synchronise(id string, hash common.Hash) error {
if p == nil {
return errUnknownPeer
}
return d.syncWithPeer(p, hash)
return d.syncWithPeer(p, hash, td)
}
// Has checks if the downloader knows about a particular hash, meaning that its
@ -306,7 +307,7 @@ func (d *Downloader) Has(hash common.Hash) bool {
// syncWithPeer starts a block synchronization based on the hash chain from the
// specified peer and head hash.
func (d *Downloader) syncWithPeer(p *peer, hash common.Hash) (err error) {
func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err error) {
d.mux.Post(StartEvent{})
defer func() {
// reset on error
@ -335,7 +336,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash) (err error) {
return err
}
errc := make(chan error, 2)
go func() { errc <- d.fetchHashes(p, number+1) }()
go func() { errc <- d.fetchHashes(p, td, number+1) }()
go func() { errc <- d.fetchBlocks(number + 1) }()
// If any fetcher fails, cancel the other
@ -788,7 +789,7 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
// fetchHashes keeps retrieving hashes from the requested number, until no more
// are returned, potentially throttling on the way.
func (d *Downloader) fetchHashes(p *peer, from uint64) error {
func (d *Downloader) fetchHashes(p *peer, td *big.Int, from uint64) error {
glog.V(logger.Debug).Infof("%v: downloading hashes from #%d", p, from)
// Create a timeout timer, and the associated hash fetcher
@ -827,8 +828,19 @@ func (d *Downloader) fetchHashes(p *peer, from uint64) error {
case d.processCh <- false:
case <-d.cancelCh:
}
// Error out if no hashes were retrieved at all
if !gotHashes {
// If no hashes 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 hashes up from 11 (R's TD was higher, it must have something)
// R: Nothing to give
if !gotHashes && td.Cmp(d.headBlock().Td) > 0 {
return errStallingPeer
}
return nil

74
eth/downloader/downloader_test.go
View File

@ -97,8 +97,18 @@ func newTester() *downloadTester {
}
// sync starts synchronizing with a remote peer, blocking until it completes.
func (dl *downloadTester) sync(id string) error {
err := dl.downloader.synchronise(id, dl.peerHashes[id][0])
func (dl *downloadTester) sync(id string, td *big.Int) error {
hash := dl.peerHashes[id][0]
// If no particular TD was requested, load from the peer's blockchain
if td == nil {
td = big.NewInt(1)
if block, ok := dl.peerBlocks[id][hash]; ok {
td = block.Td
}
}
err := dl.downloader.synchronise(id, hash, td)
for {
// If the queue is empty and processing stopped, break
hashes, blocks := dl.downloader.queue.Size()
@ -261,7 +271,7 @@ func TestSynchronisation60(t *testing.T) {
tester.newPeer("peer", eth60, hashes, blocks)
// Synchronise with the peer and make sure all blocks were retrieved
if err := tester.sync("peer"); err != nil {
if err := tester.sync("peer", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
@ -281,7 +291,7 @@ func TestCanonicalSynchronisation61(t *testing.T) {
tester.newPeer("peer", eth61, hashes, blocks)
// Synchronise with the peer and make sure all blocks were retrieved
if err := tester.sync("peer"); err != nil {
if err := tester.sync("peer", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
@ -312,7 +322,7 @@ func testThrottling(t *testing.T, protocol int) {
// Start a synchronisation concurrently
errc := make(chan error)
go func() {
errc <- tester.sync("peer")
errc <- tester.sync("peer", nil)
}()
// Iteratively take some blocks, always checking the retrieval count
for len(tester.ownBlocks) < targetBlocks+1 {
@ -361,14 +371,14 @@ func TestForkedSynchronisation61(t *testing.T) {
tester.newPeer("fork B", eth61, hashesB, blocksB)
// Synchronise with the peer and make sure all blocks were retrieved
if err := tester.sync("fork A"); err != nil {
if err := tester.sync("fork A", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != common+fork+1 {
t.Fatalf("synchronised block mismatch: have %v, want %v", imported, common+fork+1)
}
// Synchronise with the second peer and make sure that fork is pulled too
if err := tester.sync("fork B"); err != nil {
if err := tester.sync("fork B", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != common+2*fork+1 {
@ -411,7 +421,7 @@ func testCancel(t *testing.T, protocol int) {
t.Errorf("block or hash count mismatch: %d hashes, %d blocks, want 0", hashCount, blockCount)
}
// Synchronise with the peer, but cancel afterwards
if err := tester.sync("peer"); err != nil {
if err := tester.sync("peer", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
tester.downloader.cancel()
@ -438,14 +448,14 @@ func testMultiSynchronisation(t *testing.T, protocol int) {
}
// Synchronise with the middle peer and make sure half of the blocks were retrieved
id := fmt.Sprintf("peer #%d", targetPeers/2)
if err := tester.sync(id); err != nil {
if err := tester.sync(id, nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != len(tester.peerHashes[id]) {
t.Fatalf("synchronised block mismatch: have %v, want %v", imported, len(tester.peerHashes[id]))
}
// Synchronise with the best peer and make sure everything is retrieved
if err := tester.sync("peer #0"); err != nil {
if err := tester.sync("peer #0", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
@ -469,7 +479,7 @@ func TestSlowSynchronisation60(t *testing.T) {
// Try to sync with the peers (pull hashes from fast)
start := time.Now()
if err := tester.sync("fast"); err != nil {
if err := tester.sync("fast", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
@ -497,14 +507,14 @@ func TestNonExistingParentAttack60(t *testing.T) {
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 {
if err := tester.sync("attack", nil); err == nil {
t.Fatalf("block synchronization succeeded")
}
if tester.hasBlock(hashes[0]) {
t.Fatalf("tester accepted unknown-parent block: %v", blocks[hashes[0]])
}
// Try to synchronize with the valid chain and make sure it succeeds
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if !tester.hasBlock(tester.peerHashes["valid"][0]) {
@ -525,7 +535,7 @@ func TestRepeatingHashAttack60(t *testing.T) { // TODO: Is this thing valid??
// Try and sync with the malicious node
errc := make(chan error)
go func() {
errc <- tester.sync("attack")
errc <- tester.sync("attack", nil)
}()
// Make sure that syncing returns and does so with a failure
select {
@ -537,7 +547,7 @@ func TestRepeatingHashAttack60(t *testing.T) { // TODO: Is this thing valid??
}
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -555,11 +565,11 @@ func TestNonExistingBlockAttack60(t *testing.T) {
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 {
if err := tester.sync("attack", nil); err != errPeersUnavailable {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errPeersUnavailable)
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -583,11 +593,11 @@ func TestInvalidHashOrderAttack60(t *testing.T) {
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 {
if err := tester.sync("attack", nil); err != errInvalidChain {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errInvalidChain)
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -611,11 +621,11 @@ func TestMadeupHashChainAttack60(t *testing.T) {
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 {
if err := tester.sync("attack", nil); err != errCrossCheckFailed {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errCrossCheckFailed)
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -636,7 +646,7 @@ func TestMadeupHashChainDrippingAttack60(t *testing.T) {
// Try and sync with the attacker, one hash at a time
tester.maxHashFetch = 1
tester.newPeer("attack", eth60, randomHashes, nil)
if err := tester.sync("attack"); err != errStallingPeer {
if err := tester.sync("attack", nil); err != errStallingPeer {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
}
}
@ -659,7 +669,7 @@ func TestMadeupBlockChainAttack60(t *testing.T) {
// Try and sync with the malicious node and check that it fails
tester := newTester()
tester.newPeer("attack", eth60, gapped, blocks)
if err := tester.sync("attack"); err != errCrossCheckFailed {
if err := tester.sync("attack", nil); err != errCrossCheckFailed {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errCrossCheckFailed)
}
// Ensure that a valid chain can still pass sync
@ -667,7 +677,7 @@ func TestMadeupBlockChainAttack60(t *testing.T) {
crossCheckCycle = defaultCrossCheckCycle
tester.newPeer("valid", eth60, hashes, blocks)
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -690,7 +700,7 @@ func TestBannedChainStarvationAttack60(t *testing.T) {
// the head of the invalid chain is blocked too.
for banned := tester.downloader.banned.Size(); ; {
// Try to sync with the attacker, check hash chain failure
if err := tester.sync("attack"); err != errInvalidChain {
if err := tester.sync("attack", nil); err != errInvalidChain {
if tester.downloader.banned.Has(forkHashes[0]) && err == errBannedHead {
break
}
@ -711,7 +721,7 @@ func TestBannedChainStarvationAttack60(t *testing.T) {
t.Fatalf("banned attacker registered: %v", peer)
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -743,7 +753,7 @@ func TestBannedChainMemoryExhaustionAttack60(t *testing.T) {
// the head of the invalid chain is blocked too.
for {
// Try to sync with the attacker, check hash chain failure
if err := tester.sync("attack"); err != errInvalidChain {
if err := tester.sync("attack", nil); err != errInvalidChain {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errInvalidChain)
}
// Short circuit if the entire chain was banned.
@ -754,7 +764,7 @@ func TestBannedChainMemoryExhaustionAttack60(t *testing.T) {
if bans := tester.downloader.banned.Size(); bans > maxBannedHashes {
t.Fatalf("ban cap exceeded: have %v, want max %v", bans, maxBannedHashes)
}
for hash, _ := range core.BadHashes {
for hash := range core.BadHashes {
if !tester.downloader.banned.Has(hash) {
t.Fatalf("hard coded ban evacuated: %x", hash)
}
@ -764,7 +774,7 @@ func TestBannedChainMemoryExhaustionAttack60(t *testing.T) {
MaxBlockFetch = defaultMaxBlockFetch
maxBannedHashes = defaultMaxBannedHashes
if err := tester.sync("valid"); err != nil {
if err := tester.sync("valid", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -790,7 +800,7 @@ func TestOverlappingDeliveryAttack60(t *testing.T) {
return rawGetBlocks(append(request, hashes[0]))
}
// Test that synchronisation can complete, check for import success
if err := tester.sync("attack"); err != nil {
if err := tester.sync("attack", nil); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
start := time.Now()
@ -807,7 +817,7 @@ func TestOverlappingDeliveryAttack60(t *testing.T) {
func TestHighTDStarvationAttack61(t *testing.T) {
tester := newTester()
tester.newPeer("attack", eth61, []common.Hash{genesis.Hash()}, nil)
if err := tester.sync("attack"); err != errStallingPeer {
if err := tester.sync("attack", big.NewInt(1000000)); err != errStallingPeer {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
}
}
@ -849,7 +859,7 @@ func TestHashAttackerDropping(t *testing.T) {
// Simulate a synchronisation and check the required result
tester.downloader.synchroniseMock = func(string, common.Hash) error { return tt.result }
tester.downloader.Synchronise(id, genesis.Hash())
tester.downloader.Synchronise(id, genesis.Hash(), big.NewInt(1000))
if _, ok := tester.peerHashes[id]; !ok != tt.drop {
t.Errorf("test %d: peer drop mismatch for %v: have %v, want %v", i, tt.result, !ok, tt.drop)
}

2
eth/sync.go
View File

@ -164,5 +164,5 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
return
}
// Otherwise try to sync with the downloader
pm.downloader.Synchronise(peer.id, peer.Head())
pm.downloader.Synchronise(peer.id, peer.Head(), peer.Td())
}