package downloader
import (
"encoding/binary"
"errors"
"fmt"
"math/big"
"sync/atomic"
"testing"
"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"
)
var (
knownHash = common.Hash{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
unknownHash = common.Hash{2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2}
bannedHash = common.Hash{3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3}
genesis = createBlock(1, common.Hash{}, knownHash)
)
// idCounter is used by the createHashes method the generate deterministic but unique hashes
var idCounter = int64(2) // #1 is the genesis block
// createHashes generates a batch of hashes rooted at a specific point in the chain.
func createHashes(amount int, root common.Hash) (hashes []common.Hash) {
hashes = make([]common.Hash, amount+1)
hashes[len(hashes)-1] = root
for i := 0; i < len(hashes)-1; i++ {
binary.BigEndian.PutUint64(hashes[i][:8], uint64(idCounter))
idCounter++
}
return
}
// createBlock assembles a new block at the given chain height.
func createBlock(i int, parent, hash common.Hash) *types.Block {
header := &types.Header{Number: big.NewInt(int64(i))}
block := types.NewBlockWithHeader(header)
block.HeaderHash = hash
block.ParentHeaderHash = parent
return block
}
// copyBlock makes a deep copy of a block suitable for local modifications.
func copyBlock(block *types.Block) *types.Block {
return createBlock(int(block.Number().Int64()), block.ParentHeaderHash, block.HeaderHash)
}
func createBlocksFromHashes(hashes []common.Hash) map[common.Hash]*types.Block {
blocks := make(map[common.Hash]*types.Block)
for i := 0; i < len(hashes); i++ {
parent := knownHash
if i < len(hashes)-1 {
parent = hashes[i+1]
}
blocks[hashes[i]] = createBlock(len(hashes)-i, parent, hashes[i])
}
return blocks
}
type downloadTester struct {
downloader *Downloader
ownHashes []common.Hash // Hash chain belonging to the tester
ownBlocks map[common.Hash]*types.Block // Blocks belonging to the tester
peerHashes map[string][]common.Hash // Hash chain belonging to different test peers
peerBlocks map[string]map[common.Hash]*types.Block // Blocks belonging to different test peers
maxHashFetch int // Overrides the maximum number of retrieved hashes
}
func newTester() *downloadTester {
tester := &downloadTester{
ownHashes: []common.Hash{knownHash},
ownBlocks: map[common.Hash]*types.Block{knownHash: genesis},
peerHashes: make(map[string][]common.Hash),
peerBlocks: make(map[string]map[common.Hash]*types.Block),
}
var mux event.TypeMux
downloader := New(&mux, tester.hasBlock, tester.getBlock, tester.insertChain, tester.dropPeer)
tester.downloader = downloader
return tester
}
// 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])
for atomic.LoadInt32(&dl.downloader.processing) == 1 {
time.Sleep(time.Millisecond)
}
return err
}
// 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
}
// getBlock retrieves a block from the testers canonical chain.
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))
if err == nil {
// Assign the owned hashes and blocks to the peer (deep copy)
dl.peerHashes[id] = make([]common.Hash, len(hashes))
copy(dl.peerHashes[id], hashes)
dl.peerBlocks[id] = make(map[common.Hash]*types.Block)
for hash, block := range blocks {
dl.peerBlocks[id][hash] = copyBlock(block)
}
}
return err
}
// dropPeer simulates a hard peer removal from the connection pool.
func (dl *downloadTester) dropPeer(id string) {
delete(dl.peerHashes, id)
delete(dl.peerBlocks, id)
dl.downloader.UnregisterPeer(id)
}
// peerGetBlocksFn constructs a getHashes 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) peerGetHashesFn(id string) func(head common.Hash) error {
return func(head common.Hash) error {
limit := MaxHashFetch
if dl.maxHashFetch > 0 {
limit = dl.maxHashFetch
}
// Gather the next batch of hashes
hashes := dl.peerHashes[id]
result := make([]common.Hash, 0, limit)
for i, hash := range hashes {
if hash == head {
i++
for len(result) < cap(result) && i < len(hashes) {
result = append(result, hashes[i])
i++
}
break
}
}
// Delay delivery a bit to allow attacks to unfold
go func() {
time.Sleep(time.Millisecond)
dl.downloader.DeliverHashes(id, result)
}()
return nil
}
}
// peerGetBlocksFn constructs a getBlocks function associated with a particular
// peer in the download tester. The returned function can be used to retrieve
// batches of blocks from the particularly requested peer.
func (dl *downloadTester) peerGetBlocksFn(id string) func([]common.Hash) error {
return func(hashes []common.Hash) error {
blocks := dl.peerBlocks[id]
result := make([]*types.Block, 0, len(hashes))
for _, hash := range hashes {
if block, ok := blocks[hash]; ok {
result = append(result, block)
}
}
go dl.downloader.DeliverBlocks(id, result)
return nil
}
}
// Tests that simple synchronization, without throttling from a good peer works.
func TestSynchronisation(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 make sure all blocks were retrieved
if err := tester.sync("peer"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if imported := len(tester.ownBlocks); imported != targetBlocks+1 {
t.Fatalf("synchronised block mismatch: have %v, want %v", imported, targetBlocks+1)
}
}
// Tests that an inactive downloader will not accept incoming hashes and blocks.
func TestInactiveDownloader(t *testing.T) {
tester := newTester()
// Check that neither hashes nor blocks are accepted
if err := tester.downloader.DeliverHashes("bad peer", []common.Hash{}); err != errNoSyncActive {
t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
}
if err := tester.downloader.DeliverBlocks("bad peer", []*types.Block{}); err != errNoSyncActive {
t.Errorf("error mismatch: have %v, want %v", err, errNoSyncActive)
}
}
// Tests that a canceled download wipes all previously accumulated state.
func TestCancel(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)
// 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)
}
// 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)
}
}
// Tests that if a large batch of blocks are being downloaded, it is throttled
// until the cached blocks are retrieved.
func TestThrottling(t *testing.T) {
// Create a long block chain to download and the tester
targetBlocks := 8 * blockCacheLimit
hashes := createHashes(targetBlocks, knownHash)
blocks := createBlocksFromHashes(hashes)
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 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)
cached = len(tester.downloader.queue.blockPool)
if cached == blockCacheLimit || len(tester.ownBlocks)+cached == targetBlocks+1 {
break
}
}
// 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)
}
<-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)
}
}
// Tests that if a peer returns an invalid chain with a block pointing to a non-
// existing parent, it is correctly detected and handled.
func TestNonExistingParentAttack(t *testing.T) {
tester := newTester()
// Forge a single-link chain with a forged header
hashes := createHashes(1, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
hashes = createHashes(1, knownHash)
blocks = createBlocksFromHashes(hashes)
blocks[hashes[0]].ParentHeaderHash = unknownHash
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("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 {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if !tester.hasBlock(tester.peerHashes["valid"][0]) {
t.Fatalf("tester didn't accept known-parent block: %v", tester.peerBlocks["valid"][hashes[0]])
}
}
// Tests that if a malicious peers keeps sending us repeating hashes, we don't
// loop indefinitely.
func TestRepeatingHashAttack(t *testing.T) { // TODO: Is this thing valid??
tester := newTester()
// Create a valid chain, but drop the last link
hashes := createHashes(blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
tester.newPeer("attack", hashes[:len(hashes)-1], blocks)
// Try and sync with the malicious node
errc := make(chan error)
go func() {
errc <- tester.sync("attack")
}()
// Make sure that syncing returns and does so with a failure
select {
case <-time.After(time.Second):
t.Fatalf("synchronisation blocked")
case err := <-errc:
if err == nil {
t.Fatalf("synchronisation succeeded")
}
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that if a malicious peers returns a non-existent block hash, it should
// eventually time out and the sync reattempted.
func TestNonExistingBlockAttack(t *testing.T) {
tester := newTester()
// Create a valid chain, but forge the last link
hashes := createHashes(blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
hashes[len(hashes)/2] = unknownHash
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
if err := tester.sync("attack"); 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 {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that if a malicious peer is returning hashes in a weird order, that the
// sync throttler doesn't choke on them waiting for the valid blocks.
func TestInvalidHashOrderAttack(t *testing.T) {
tester := newTester()
// Create a valid long chain, but reverse some hashes within
hashes := createHashes(4*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
chunk1 := make([]common.Hash, blockCacheLimit)
chunk2 := make([]common.Hash, blockCacheLimit)
copy(chunk1, hashes[blockCacheLimit:2*blockCacheLimit])
copy(chunk2, hashes[2*blockCacheLimit:3*blockCacheLimit])
copy(hashes[2*blockCacheLimit:], chunk1)
copy(hashes[blockCacheLimit:], chunk2)
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
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.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that if a malicious peer makes up a random hash chain and tries to push
// indefinitely, it actually gets caught with it.
func TestMadeupHashChainAttack(t *testing.T) {
tester := newTester()
blockSoftTTL = 100 * time.Millisecond
crossCheckCycle = 25 * time.Millisecond
// Create a long chain of hashes without backing blocks
hashes := createHashes(4*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
tester.newPeer("attack", createHashes(1024*blockCacheLimit, knownHash), nil)
// Try and sync with the malicious node and check that it fails
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.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that if a malicious peer makes up a random hash chain, and tries to push
// indefinitely, one hash at a time, it actually gets caught with it. The reason
// this is separate from the classical made up chain attack is that sending hashes
// one by one prevents reliable block/parent verification.
func TestMadeupHashChainDrippingAttack(t *testing.T) {
// Create a random chain of hashes to drip
hashes := createHashes(16*blockCacheLimit, knownHash)
tester := newTester()
// Try and sync with the attacker, one hash at a time
tester.maxHashFetch = 1
tester.newPeer("attack", hashes, nil)
if err := tester.sync("attack"); err != errStallingPeer {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errStallingPeer)
}
}
// Tests that if a malicious peer makes up a random block chain, and tried to
// push indefinitely, it actually gets caught with it.
func TestMadeupBlockChainAttack(t *testing.T) {
defaultBlockTTL := blockSoftTTL
defaultCrossCheckCycle := crossCheckCycle
blockSoftTTL = 100 * time.Millisecond
crossCheckCycle = 25 * time.Millisecond
// Create a long chain of blocks and simulate an invalid chain by dropping every second
hashes := createHashes(16*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
gapped := make([]common.Hash, len(hashes)/2)
for i := 0; i < len(gapped); i++ {
gapped[i] = hashes[2*i]
}
// Try and sync with the malicious node and check that it fails
tester := newTester()
tester.newPeer("attack", gapped, blocks)
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
tester.newPeer("valid", hashes, blocks)
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Advanced form of the above forged blockchain attack, where not only does the
// attacker make up a valid hashes for random blocks, but also forges the block
// parents to point to existing hashes.
func TestMadeupParentBlockChainAttack(t *testing.T) {
tester := newTester()
defaultBlockTTL := blockSoftTTL
defaultCrossCheckCycle := crossCheckCycle
blockSoftTTL = 100 * time.Millisecond
crossCheckCycle = 25 * time.Millisecond
// Create a long chain of blocks and simulate an invalid chain by dropping every second
hashes := createHashes(16*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
for _, block := range blocks {
block.ParentHeaderHash = knownHash // Simulate pointing to already known hash
}
tester.newPeer("attack", hashes, blocks)
// Try and sync with the malicious node and check that it fails
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.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
// the downloader, it will not keep refetching the same chain indefinitely, but
// gradually block pieces of it, until it's head is also blocked.
func TestBannedChainStarvationAttack(t *testing.T) {
// Create the tester and ban the selected hash
tester := newTester()
tester.downloader.banned.Add(bannedHash)
// Construct a valid chain, for it and ban the fork
hashes := createHashes(8*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
fork := len(hashes)/2 - 23
hashes = append(createHashes(4*blockCacheLimit, bannedHash), hashes[fork:]...)
blocks = createBlocksFromHashes(hashes)
tester.newPeer("attack", hashes, blocks)
// Iteratively try to sync, and verify that the banned hash list grows until
// 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 tester.downloader.banned.Has(hashes[0]) && err == errBannedHead {
break
}
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errInvalidChain)
}
// Check that the ban list grew with at least 1 new item, or all banned
bans := tester.downloader.banned.Size()
if bans < banned+1 {
t.Fatalf("ban count mismatch: have %v, want %v+", bans, banned+1)
}
banned = bans
}
// Check that after banning an entire chain, bad peers get dropped
if err := tester.newPeer("new attacker", hashes, blocks); err != errBannedHead {
t.Fatalf("peer registration mismatch: have %v, want %v", err, errBannedHead)
}
if peer := tester.downloader.peers.Peer("new attacker"); peer != nil {
t.Fatalf("banned attacker registered: %v", peer)
}
// Ensure that a valid chain can still pass sync
if err := tester.sync("valid"); err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
}
// Tests that if a peer sends excessively many/large invalid chains that are
// gradually banned, it will have an upper limit on the consumed memory and also
// the origin bad hashes will not be evacuated.
func TestBannedChainMemoryExhaustionAttack(t *testing.T) {
// Create the tester and ban the selected hash
tester := newTester()
tester.downloader.banned.Add(bannedHash)
// Reduce the test size a bit
defaultMaxBlockFetch := MaxBlockFetch
defaultMaxBannedHashes := maxBannedHashes
MaxBlockFetch = 4
maxBannedHashes = 256
// Construct a banned chain with more chunks than the ban limit
hashes := createHashes(8*blockCacheLimit, knownHash)
blocks := createBlocksFromHashes(hashes)
tester.newPeer("valid", hashes, blocks)
fork := len(hashes)/2 - 23
hashes = append(createHashes(maxBannedHashes*MaxBlockFetch, bannedHash), hashes[fork:]...)
blocks = createBlocksFromHashes(hashes)
tester.newPeer("attack", hashes, blocks)
// Iteratively try to sync, and verify that the banned hash list grows until
// 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 {
t.Fatalf("synchronisation error mismatch: have %v, want %v", err, errInvalidChain)
}
// Short circuit if the entire chain was banned
if tester.downloader.banned.Has(hashes[0]) {
break
}
// Otherwise ensure we never exceed the memory allowance and the hard coded bans are untouched
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 {
if !tester.downloader.banned.Has(hash) {
t.Fatalf("hard coded ban evacuated: %x", hash)
}
}
}
// Ensure that a valid chain can still pass sync
MaxBlockFetch = defaultMaxBlockFetch
maxBannedHashes = defaultMaxBannedHashes
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 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
{errCancelChainImport, 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, []common.Hash{knownHash}, 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)
}
// Simulate a synchronisation and check the required result
tester.downloader.synchroniseMock = func(string, common.Hash) error { return tt.result }
tester.downloader.Synchronise(id, knownHash)
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)
}
}
}
// 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)
}
}
}
