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eth, eth/downloader: move block processing into the downlaoder

This commit is contained in:
Péter Szilágyi 2015-06-12 13:35:29 +03:00
parent 0fc71877a7
commit fc7abd9886
4 changed files with 255 additions and 233 deletions
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177
eth/downloader/downloader.go
View File

@ -3,6 +3,7 @@ package downloader
import (
"bytes"
"errors"
"math"
"math/rand"
"sync"
"sync/atomic"
@ -28,25 +29,27 @@ var (
crossCheckCycle = time.Second // Period after which to check for expired cross checks
maxBannedHashes = 4096 // Number of bannable hashes before phasing old ones out
maxBlockProcess = 256 // Number of blocks to import at once into the chain
)
var (
errBusy = errors.New("busy")
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")
errEmptyHashSet = errors.New("empty hash set by peer")
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")
errCancelHashFetch = errors.New("hash fetching cancelled (requested)")
errCancelBlockFetch = errors.New("block downloading cancelled (requested)")
errNoSyncActive = errors.New("no sync active")
errBusy = errors.New("busy")
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")
errEmptyHashSet = errors.New("empty hash set by peer")
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")
errCancelHashFetch = errors.New("hash fetching canceled (requested)")
errCancelBlockFetch = errors.New("block downloading canceled (requested)")
errCancelChainImport = errors.New("chain importing canceled (requested)")
errNoSyncActive = errors.New("no sync active")
)
// hashCheckFn is a callback type for verifying a hash's presence in the local chain.
@ -55,6 +58,9 @@ type hashCheckFn func(common.Hash) bool
// blockRetrievalFn is a callback type for retrieving a block from the local chain.
type blockRetrievalFn func(common.Hash) *types.Block
// chainInsertFn is a callback type to insert a batch of blocks into the local chain.
type chainInsertFn func(types.Blocks) (int, error)
// peerDropFn is a callback type for dropping a peer detected as malicious.
type peerDropFn func(id string)
@ -88,13 +94,15 @@ type Downloader struct {
importLock sync.Mutex
// Callbacks
hasBlock hashCheckFn // Checks if a block is present in the chain
getBlock blockRetrievalFn // Retrieves a block from the chain
dropPeer peerDropFn // Retrieved the TD of our own chain
hasBlock hashCheckFn // Checks if a block is present in the chain
getBlock blockRetrievalFn // Retrieves a block from the chain
insertChain chainInsertFn // Injects a batch of blocks into the chain
dropPeer peerDropFn // Retrieved the TD of our own chain
// Status
synchroniseMock func(id string, hash common.Hash) error // Replacement for synchronise during testing
synchronising int32
processing int32
notified int32
// Channels
@ -113,18 +121,19 @@ 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, dropPeer peerDropFn) *Downloader {
func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock blockRetrievalFn, insertChain chainInsertFn, dropPeer peerDropFn) *Downloader {
// Create the base downloader
downloader := &Downloader{
mux: mux,
queue: newQueue(),
peers: newPeerSet(),
hasBlock: hasBlock,
getBlock: getBlock,
dropPeer: dropPeer,
newPeerCh: make(chan *peer, 1),
hashCh: make(chan hashPack, 1),
blockCh: make(chan blockPack, 1),
mux: mux,
queue: newQueue(),
peers: newPeerSet(),
hasBlock: hasBlock,
getBlock: getBlock,
insertChain: insertChain,
dropPeer: dropPeer,
newPeerCh: make(chan *peer, 1),
hashCh: make(chan hashPack, 1),
blockCh: make(chan blockPack, 1),
}
// Inject all the known bad hashes
downloader.banned = set.New()
@ -157,7 +166,7 @@ func (d *Downloader) Stats() (pending int, cached int, importing int, estimate t
return
}
// Synchronising returns the state of the downloader
// Synchronising returns whether the downloader is currently retrieving blocks.
func (d *Downloader) Synchronising() bool {
return atomic.LoadInt32(&d.synchronising) > 0
}
@ -260,19 +269,6 @@ func (d *Downloader) synchronise(id string, hash common.Hash) error {
return d.syncWithPeer(p, hash)
}
// TakeBlocks takes blocks from the queue and yields them to the caller.
func (d *Downloader) TakeBlocks() []*Block {
blocks := d.queue.TakeBlocks()
if len(blocks) > 0 {
d.importLock.Lock()
d.importStart = time.Now()
d.importQueue = blocks
d.importDone = 0
d.importLock.Unlock()
}
return blocks
}
// Has checks if the downloader knows about a particular hash, meaning that its
// either already downloaded of pending retrieval.
func (d *Downloader) Has(hash common.Hash) bool {
@ -307,19 +303,16 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash) (err error) {
// Cancel cancels all of the operations and resets the queue. It returns true
// if the cancel operation was completed.
func (d *Downloader) Cancel() bool {
// If we're not syncing just return.
hs, bs := d.queue.Size()
if atomic.LoadInt32(&d.synchronising) == 0 && hs == 0 && bs == 0 {
return false
}
func (d *Downloader) Cancel() {
// Close the current cancel channel
d.cancelLock.Lock()
select {
case <-d.cancelCh:
// Channel was already closed
default:
close(d.cancelCh)
if d.cancelCh != nil {
select {
case <-d.cancelCh:
// Channel was already closed
default:
close(d.cancelCh)
}
}
d.cancelLock.Unlock()
@ -330,11 +323,11 @@ func (d *Downloader) Cancel() bool {
d.importQueue = nil
d.importDone = 0
d.importLock.Unlock()
return true
}
// XXX Make synchronous
// fetchHahes starts retrieving hashes backwards from a specific peer and hash,
// up until it finds a common ancestor. If the source peer times out, alternative
// ones are tried for continuation.
func (d *Downloader) fetchHashes(p *peer, h common.Hash) error {
var (
start = time.Now()
@ -530,10 +523,13 @@ out:
glog.V(logger.Detail).Infof("%s: no blocks delivered", peer)
break
}
// All was successful, promote the peer
// All was successful, promote the peer and potentially start processing
peer.Promote()
peer.SetIdle()
glog.V(logger.Detail).Infof("%s: delivered %d blocks", peer, len(blockPack.blocks))
if atomic.LoadInt32(&d.processing) == 0 {
go d.process()
}
case errInvalidChain:
// The hash chain is invalid (blocks are not ordered properly), abort
@ -709,6 +705,71 @@ func (d *Downloader) banBlocks(peerId string, head common.Hash) error {
}
}
// process takes blocks from the queue and tries to import them into the chain.
func (d *Downloader) process() (err error) {
// Make sure only one goroutine is ever allowed to process blocks at once
if !atomic.CompareAndSwapInt32(&d.processing, 0, 1) {
return
}
// If the processor just exited, but there are freshly pending items, try to
// reenter. This is needed because the goroutine spinned up for processing
// the fresh blocks might have been rejected entry to to this present thread
// not yet releasing the `processing` state.
defer func() {
if err == nil && d.queue.GetHeadBlock() != nil {
err = d.process()
}
}()
// Release the lock upon exit (note, before checking for reentry!)
defer atomic.StoreInt32(&d.processing, 0)
// Fetch the current cancel channel to allow termination
d.cancelLock.RLock()
cancel := d.cancelCh
d.cancelLock.RUnlock()
// Repeat the processing as long as there are blocks to import
for {
// Fetch the next batch of blocks
blocks := d.queue.TakeBlocks()
if len(blocks) == 0 {
return nil
}
// Reset the import statistics
d.importLock.Lock()
d.importStart = time.Now()
d.importQueue = blocks
d.importDone = 0
d.importLock.Unlock()
// Actually import the blocks
glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
for len(blocks) != 0 { // TODO: quit
// Check for any termination requests
select {
case <-cancel:
return errCancelChainImport
default:
}
// Retrieve the first batch of blocks to insert
max := int(math.Min(float64(len(blocks)), float64(maxBlockProcess)))
raw := make(types.Blocks, 0, max)
for _, block := range blocks[:max] {
raw = append(raw, block.RawBlock)
}
// Try to inset the blocks, drop the originating peer if there's an error
index, err := d.insertChain(raw)
if err != nil {
glog.V(logger.Debug).Infoln("Block #%d import failed:", raw[index].NumberU64(), err)
d.dropPeer(blocks[index].OriginPeer)
d.Cancel()
return errCancelChainImport
}
blocks = blocks[max:]
}
}
}
// DeliverBlocks injects a new batch of blocks received from a remote node.
// This is usually invoked through the BlocksMsg by the protocol handler.
func (d *Downloader) DeliverBlocks(id string, blocks []*types.Block) error {

256
eth/downloader/downloader_test.go
View File

@ -2,8 +2,10 @@ package downloader
import (
"encoding/binary"
"errors"
"fmt"
"math/big"
"sync/atomic"
"testing"
"time"
@ -81,7 +83,7 @@ func newTester() *downloadTester {
peerBlocks: make(map[string]map[common.Hash]*types.Block),
}
var mux event.TypeMux
downloader := New(&mux, tester.hasBlock, tester.getBlock, tester.dropPeer)
downloader := New(&mux, tester.hasBlock, tester.getBlock, tester.insertChain, tester.dropPeer)
tester.downloader = downloader
return tester
@ -89,44 +91,14 @@ func newTester() *downloadTester {
// sync starts synchronizing with a remote peer, blocking until it completes.
func (dl *downloadTester) sync(id string) error {
return dl.downloader.synchronise(id, dl.peerHashes[id][0])
err := dl.downloader.synchronise(id, dl.peerHashes[id][0])
for atomic.LoadInt32(&dl.downloader.processing) == 1 {
time.Sleep(time.Millisecond)
}
return err
}
// syncTake is starts synchronising with a remote peer, but concurrently it also
// starts fetching blocks that the downloader retrieved. IT blocks until both go
// routines terminate.
func (dl *downloadTester) syncTake(id string) ([]*Block, error) {
// Start a block collector to take blocks as they become available
done := make(chan struct{})
took := []*Block{}
go func() {
for running := true; running; {
select {
case <-done:
running = false
default:
time.Sleep(time.Millisecond)
}
// Take a batch of blocks and accumulate
blocks := dl.downloader.TakeBlocks()
for _, block := range blocks {
dl.ownHashes = append(dl.ownHashes, block.RawBlock.Hash())
dl.ownBlocks[block.RawBlock.Hash()] = block.RawBlock
}
took = append(took, blocks...)
}
done <- struct{}{}
}()
// Start the downloading, sync the taker and return
err := dl.sync(id)
done <- struct{}{}
<-done
return took, err
}
// hasBlock checks if a block is present in the testers canonical chain.
// hasBlock checks if a block is pres ent in the testers canonical chain.
func (dl *downloadTester) hasBlock(hash common.Hash) bool {
return dl.getBlock(hash) != nil
}
@ -136,6 +108,18 @@ func (dl *downloadTester) getBlock(hash common.Hash) *types.Block {
return dl.ownBlocks[hash]
}
// insertChain injects a new batch of blocks into the simulated chain.
func (dl *downloadTester) insertChain(blocks types.Blocks) (int, error) {
for i, block := range blocks {
if _, ok := dl.ownBlocks[block.ParentHash()]; !ok {
return i, errors.New("unknown parent")
}
dl.ownHashes = append(dl.ownHashes, block.Hash())
dl.ownBlocks[block.Hash()] = block
}
return len(blocks), nil
}
// 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 {
err := dl.downloader.RegisterPeer(id, hashes[0], dl.peerGetHashesFn(id), dl.peerGetBlocksFn(id))
@ -223,27 +207,8 @@ func TestSynchronisation(t *testing.T) {
if err := tester.sync("peer"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if queued := len(tester.downloader.queue.blockPool); queued != targetBlocks {
t.Fatalf("synchronised block mismatch: have %v, want %v", queued, targetBlocks)
}
}
// Tests that the synchronized blocks can be correctly retrieved.
func TestBlockTaking(t *testing.T) {
// Create a small enough block chain to download and the tester
targetBlocks := blockCacheLimit - 15
hashes := createHashes(targetBlocks, knownHash)
blocks := createBlocksFromHashes(hashes)
tester := newTester()
tester.newPeer("peer", hashes, blocks)
// Synchronise with the peer and test block retrieval
if err := tester.sync("peer"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if took := tester.downloader.TakeBlocks(); len(took) != targetBlocks {
t.Fatalf("took block mismatch: have %v, want %v", len(took), targetBlocks)
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
t.Fatalf("synchronised block mismatch: have %v, want %v", imported, targetBlocks+1)
}
}
@ -270,20 +235,20 @@ func TestCancel(t *testing.T) {
tester := newTester()
tester.newPeer("peer", hashes, blocks)
// Synchronise with the peer, but cancel afterwards
if err := tester.sync("peer"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if !tester.downloader.Cancel() {
t.Fatalf("cancel operation failed")
}
// Make sure the queue reports empty and no blocks can be taken
// Make sure canceling works with a pristine downloader
tester.downloader.Cancel()
hashCount, blockCount := tester.downloader.queue.Size()
if hashCount > 0 || blockCount > 0 {
t.Errorf("block or hash count mismatch: %d hashes, %d blocks, want 0", hashCount, blockCount)
}
if took := tester.downloader.TakeBlocks(); len(took) != 0 {
t.Errorf("taken blocks mismatch: have %d, want %d", len(took), 0)
// Synchronise with the peer, but cancel afterwards
if err := tester.sync("peer"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
tester.downloader.Cancel()
hashCount, blockCount = tester.downloader.queue.Size()
if hashCount > 0 || blockCount > 0 {
t.Errorf("block or hash count mismatch: %d hashes, %d blocks, want 0", hashCount, blockCount)
}
}
@ -298,29 +263,46 @@ func TestThrottling(t *testing.T) {
tester := newTester()
tester.newPeer("peer", hashes, blocks)
// Wrap the importer to allow stepping
done := make(chan int)
tester.downloader.insertChain = func(blocks types.Blocks) (int, error) {
n, err := tester.insertChain(blocks)
done <- n
return n, err
}
// Start a synchronisation concurrently
errc := make(chan error)
go func() {
errc <- tester.sync("peer")
}()
// Iteratively take some blocks, always checking the retrieval count
for total := 0; total < targetBlocks; {
// Wait a bit for sync to complete
for len(tester.ownBlocks) < targetBlocks+1 {
// Wait a bit for sync to throttle itself
var cached int
for start := time.Now(); time.Since(start) < 3*time.Second; {
time.Sleep(25 * time.Millisecond)
if len(tester.downloader.queue.blockPool) == blockCacheLimit {
cached = len(tester.downloader.queue.blockPool)
if cached == blockCacheLimit || len(tester.ownBlocks)+cached == targetBlocks+1 {
break
}
}
// Fetch the next batch of blocks
took := tester.downloader.TakeBlocks()
if len(took) != blockCacheLimit {
t.Fatalf("block count mismatch: have %v, want %v", len(took), blockCacheLimit)
// Make sure we filled up the cache, then exhaust it
time.Sleep(25 * time.Millisecond) // give it a chance to screw up
if cached != blockCacheLimit && len(tester.ownBlocks)+cached < targetBlocks+1 {
t.Fatalf("block count mismatch: have %v, want %v", cached, blockCacheLimit)
}
total += len(took)
if total > targetBlocks {
t.Fatalf("target block count mismatch: have %v, want %v", total, targetBlocks)
<-done // finish previous blocking import
for cached > maxBlockProcess {
cached -= <-done
}
time.Sleep(25 * time.Millisecond) // yield to the insertion
}
<-done // finish the last blocking import
// Check that we haven't pulled more blocks than available
if len(tester.ownBlocks) > targetBlocks+1 {
t.Fatalf("target block count mismatch: have %v, want %v", len(tester.ownBlocks), targetBlocks+1)
}
if err := <-errc; err != nil {
t.Fatalf("block synchronization failed: %v", err)
@ -343,28 +325,18 @@ func TestNonExistingParentAttack(t *testing.T) {
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
if err := tester.sync("attack"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
if err := tester.sync("attack"); err == nil {
t.Fatalf("block synchronization succeeded")
}
bs := tester.downloader.TakeBlocks()
if len(bs) != 1 {
t.Fatalf("retrieved block mismatch: have %v, want %v", len(bs), 1)
if tester.hasBlock(hashes[0]) {
t.Fatalf("tester accepted unknown-parent block: %v", blocks[hashes[0]])
}
if tester.hasBlock(bs[0].RawBlock.ParentHash()) {
t.Fatalf("tester knows about the unknown hash")
}
tester.downloader.Cancel()
// Try to synchronize with the valid chain and make sure it succeeds
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
bs = tester.downloader.TakeBlocks()
if len(bs) != 1 {
t.Fatalf("retrieved block mismatch: have %v, want %v", len(bs), 1)
}
if !tester.hasBlock(bs[0].RawBlock.ParentHash()) {
t.Fatalf("tester doesn't know about the origin hash")
if !tester.hasBlock(tester.peerHashes["valid"][0]) {
t.Fatalf("tester didn't accept known-parent block: %v", tester.peerBlocks["valid"][hashes[0]])
}
}
@ -442,11 +414,11 @@ func TestInvalidHashOrderAttack(t *testing.T) {
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
if _, err := tester.syncTake("attack"); err != errInvalidChain {
if err := tester.sync("attack"); 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.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -466,11 +438,11 @@ func TestMadeupHashChainAttack(t *testing.T) {
tester.newPeer("attack", createHashes(1024*blockCacheLimit, knownHash), nil)
// Try and sync with the malicious node and check that it fails
if _, err := tester.syncTake("attack"); err != errCrossCheckFailed {
if err := tester.sync("attack"); 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.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -487,7 +459,7 @@ func TestMadeupHashChainDrippingAttack(t *testing.T) {
// Try and sync with the attacker, one hash at a time
tester.maxHashFetch = 1
tester.newPeer("attack", hashes, nil)
if _, err := tester.syncTake("attack"); err != errStallingPeer {
if err := tester.sync("attack"); err != errStallingPeer {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
}
}
@ -512,7 +484,7 @@ func TestMadeupBlockChainAttack(t *testing.T) {
// Try and sync with the malicious node and check that it fails
tester := newTester()
tester.newPeer("attack", gapped, blocks)
if _, err := tester.syncTake("attack"); err != errCrossCheckFailed {
if err := tester.sync("attack"); err != errCrossCheckFailed {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errCrossCheckFailed)
}
// Ensure that a valid chain can still pass sync
@ -520,7 +492,7 @@ func TestMadeupBlockChainAttack(t *testing.T) {
crossCheckCycle = defaultCrossCheckCycle
tester.newPeer("valid", hashes, blocks)
if _, err := tester.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -548,14 +520,14 @@ func TestMadeupParentBlockChainAttack(t *testing.T) {
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
if _, err := tester.syncTake("attack"); err != errCrossCheckFailed {
if err := tester.sync("attack"); err != errCrossCheckFailed {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errCrossCheckFailed)
}
// Ensure that a valid chain can still pass sync
blockSoftTTL = defaultBlockTTL
crossCheckCycle = defaultCrossCheckCycle
if _, err := tester.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -582,7 +554,7 @@ func TestBannedChainStarvationAttack(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.syncTake("attack"); err != errInvalidChain {
if err := tester.sync("attack"); err != errInvalidChain {
if tester.downloader.banned.Has(hashes[0]) && err == errBannedHead {
break
}
@ -603,7 +575,7 @@ func TestBannedChainStarvationAttack(t *testing.T) {
t.Fatalf("banned attacker registered: %v", peer)
}
// Ensure that a valid chain can still pass sync
if _, err := tester.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
@ -637,7 +609,7 @@ func TestBannedChainMemoryExhaustionAttack(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.syncTake("attack"); err != errInvalidChain {
if err := tester.sync("attack"); err != errInvalidChain {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errInvalidChain)
}
// Short circuit if the entire chain was banned
@ -658,33 +630,34 @@ func TestBannedChainMemoryExhaustionAttack(t *testing.T) {
MaxBlockFetch = defaultMaxBlockFetch
maxBannedHashes = defaultMaxBannedHashes
if _, err := tester.syncTake("valid"); err != nil {
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that misbehaving peers are disconnected, whilst behaving ones are not.
func TestAttackerDropping(t *testing.T) {
// Define the disconnection requirement for individual errors
func TestHashAttackerDropping(t *testing.T) {
// Define the disconnection requirement for individual hash fetch errors
tests := []struct {
result error
drop bool
}{
{nil, false}, // Sync succeeded, all is well
{errBusy, false}, // Sync is already in progress, no problem
{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
{errEmptyHashSet, true}, // No hashes 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
{errCancelHashFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
{errCancelBlockFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
{nil, false}, // Sync succeeded, all is well
{errBusy, false}, // Sync is already in progress, no problem
{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
{errEmptyHashSet, true}, // No hashes 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
{errCancelHashFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
{errCancelBlockFetch, false}, // Synchronisation was canceled, origin may be innocent, don't drop
{errCancelChainImport, false}, // Synchronisation was canceled, origin may be innocent, don't drop
}
// Run the tests and check disconnection status
tester := newTester()
@ -706,3 +679,38 @@ func TestAttackerDropping(t *testing.T) {
}
}
}
// Tests that feeding bad blocks will result in a peer drop.
func TestBlockAttackerDropping(t *testing.T) {
// Define the disconnection requirement for individual block import errors
tests := []struct {
failure bool
drop bool
}{{true, true}, {false, false}}
// 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, []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 {
t.Fatalf("test %d: registered peer not found", i)
}
// Assemble a good or bad block, depending of the test
raw := createBlock(1, knownHash, common.Hash{})
if tt.failure {
raw = createBlock(1, unknownHash, common.Hash{})
}
block := &Block{OriginPeer: id, RawBlock: raw}
// Simulate block processing and check the result
tester.downloader.queue.blockCache[0] = block
tester.downloader.process()
if _, ok := tester.peerHashes[id]; !ok != tt.drop {
t.Errorf("test %d: peer drop mismatch for %v: have %v, want %v", i, tt.failure, !ok, tt.drop)
}
}
}

2
eth/handler.go
View File

@ -80,7 +80,7 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
txsyncCh: make(chan *txsync),
quitSync: make(chan struct{}),
}
manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.removePeer)
manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.chainman.InsertChain, manager.removePeer)
manager.SubProtocol = p2p.Protocol{
Name: "eth",
Version: uint(protocolVersion),

53
eth/sync.go
View File

@ -1,9 +1,7 @@
package eth
import (
"math"
"math/rand"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
@ -15,12 +13,10 @@ import (
const (
forceSyncCycle = 10 * time.Second // Time interval to force syncs, even if few peers are available
blockProcCycle = 500 * time.Millisecond // Time interval to check for new blocks to process
notifyCheckCycle = 100 * time.Millisecond // Time interval to allow hash notifies to fulfill before hard fetching
notifyArriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
notifyFetchTimeout = 5 * time.Second // Maximum alloted time to return an explicitly requested block
minDesiredPeerCount = 5 // Amount of peers desired to start syncing
blockProcAmount = 256
// This is the target size for the packs of transactions sent by txsyncLoop.
// A pack can get larger than this if a single transactions exceeds this size.
@ -254,10 +250,10 @@ func (pm *ProtocolManager) fetcher() {
// syncer is responsible for periodically synchronising with the network, both
// downloading hashes and blocks as well as retrieving cached ones.
func (pm *ProtocolManager) syncer() {
forceSync := time.Tick(forceSyncCycle)
blockProc := time.Tick(blockProcCycle)
blockProcPend := int32(0)
// Abort any pending syncs if we terminate
defer pm.downloader.Cancel()
forceSync := time.Tick(forceSyncCycle)
for {
select {
case <-pm.newPeerCh:
@ -271,55 +267,12 @@ func (pm *ProtocolManager) syncer() {
// Force a sync even if not enough peers are present
go pm.synchronise(pm.peers.BestPeer())
case <-blockProc:
// Try to pull some blocks from the downloaded
if atomic.CompareAndSwapInt32(&blockProcPend, 0, 1) {
go func() {
pm.processBlocks()
atomic.StoreInt32(&blockProcPend, 0)
}()
}
case <-pm.quitSync:
return
}
}
}
// processBlocks retrieves downloaded blocks from the download cache and tries
// to construct the local block chain with it. Note, since the block retrieval
// order matters, access to this function *must* be synchronized/serialized.
func (pm *ProtocolManager) processBlocks() error {
pm.wg.Add(1)
defer pm.wg.Done()
// Short circuit if no blocks are available for insertion
blocks := pm.downloader.TakeBlocks()
if len(blocks) == 0 {
return nil
}
glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())
for len(blocks) != 0 && !pm.quit {
// Retrieve the first batch of blocks to insert
max := int(math.Min(float64(len(blocks)), float64(blockProcAmount)))
raw := make(types.Blocks, 0, max)
for _, block := range blocks[:max] {
raw = append(raw, block.RawBlock)
}
// Try to inset the blocks, drop the originating peer if there's an error
index, err := pm.chainman.InsertChain(raw)
if err != nil {
glog.V(logger.Debug).Infoln("Downloaded block import failed:", err)
pm.removePeer(blocks[index].OriginPeer)
pm.downloader.Cancel()
return err
}
blocks = blocks[max:]
}
return nil
}
// 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 (pm *ProtocolManager) synchronise(peer *peer) {