package downloader
import (
"encoding/binary"
"math/big"
"testing"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
)
var (
knownHash = common.Hash{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
unknownHash = common.Hash{9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9}
)
func createHashes(start, amount int) (hashes []common.Hash) {
hashes = make([]common.Hash, amount+1)
hashes[len(hashes)-1] = knownHash
for i := range hashes[:len(hashes)-1] {
binary.BigEndian.PutUint64(hashes[i][:8], uint64(i+2))
}
return
}
func createBlock(i int, prevHash, hash common.Hash) *types.Block {
header := &types.Header{Number: big.NewInt(int64(i))}
block := types.NewBlockWithHeader(header)
block.HeaderHash = hash
block.ParentHeaderHash = prevHash
return block
}
func createBlocksFromHashes(hashes []common.Hash) map[common.Hash]*types.Block {
blocks := make(map[common.Hash]*types.Block)
for i, hash := range hashes {
blocks[hash] = createBlock(len(hashes)-i, knownHash, hash)
}
return blocks
}
type downloadTester struct {
downloader *Downloader
hashes []common.Hash // Chain of hashes simulating
blocks map[common.Hash]*types.Block // Blocks associated with the hashes
chain []common.Hash // Block-chain being constructed
t *testing.T
pcount int
done chan bool
activePeerId string
}
func newTester(t *testing.T, hashes []common.Hash, blocks map[common.Hash]*types.Block) *downloadTester {
tester := &downloadTester{
t: t,
hashes: hashes,
blocks: blocks,
chain: []common.Hash{knownHash},
done: make(chan bool),
}
downloader := New(tester.hasBlock, tester.getBlock)
tester.downloader = downloader
return tester
}
func (dl *downloadTester) sync(peerId string, hash common.Hash) error {
dl.activePeerId = peerId
return dl.downloader.Synchronise(peerId, hash)
}
func (dl *downloadTester) insertBlocks(blocks types.Blocks) {
for _, block := range blocks {
dl.chain = append(dl.chain, block.Hash())
}
}
func (dl *downloadTester) hasBlock(hash common.Hash) bool {
for _, h := range dl.chain {
if h == hash {
return true
}
}
return false
}
func (dl *downloadTester) getBlock(hash common.Hash) *types.Block {
return dl.blocks[knownHash]
}
func (dl *downloadTester) getHashes(hash common.Hash) error {
dl.downloader.DeliverHashes(dl.activePeerId, dl.hashes)
return nil
}
func (dl *downloadTester) getBlocks(id string) func([]common.Hash) error {
return func(hashes []common.Hash) error {
blocks := make([]*types.Block, len(hashes))
for i, hash := range hashes {
blocks[i] = dl.blocks[hash]
}
go dl.downloader.DeliverBlocks(id, blocks)
return nil
}
}
func (dl *downloadTester) newPeer(id string, td *big.Int, hash common.Hash) {
dl.pcount++
dl.downloader.RegisterPeer(id, hash, dl.getHashes, dl.getBlocks(id))
}
func (dl *downloadTester) badBlocksPeer(id string, td *big.Int, hash common.Hash) {
dl.pcount++
// This bad peer never returns any blocks
dl.downloader.RegisterPeer(id, hash, dl.getHashes, func([]common.Hash) error {
return nil
})
}
func TestDownload(t *testing.T) {
minDesiredPeerCount = 4
blockTtl = 1 * time.Second
targetBlocks := 1000
hashes := createHashes(0, targetBlocks)
blocks := createBlocksFromHashes(hashes)
tester := newTester(t, hashes, blocks)
tester.newPeer("peer1", big.NewInt(10000), hashes[0])
tester.newPeer("peer2", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})
tester.activePeerId = "peer1"
err := tester.sync("peer1", hashes[0])
if err != nil {
t.Error("download error", err)
}
inqueue := len(tester.downloader.queue.blockCache)
if inqueue != targetBlocks {
t.Error("expected", targetBlocks, "have", inqueue)
}
}
func TestMissing(t *testing.T) {
targetBlocks := 1000
hashes := createHashes(0, 1000)
extraHashes := createHashes(1001, 1003)
blocks := createBlocksFromHashes(append(extraHashes, hashes...))
tester := newTester(t, hashes, blocks)
tester.newPeer("peer1", big.NewInt(10000), hashes[len(hashes)-1])
hashes = append(extraHashes, hashes[:len(hashes)-1]...)
tester.newPeer("peer2", big.NewInt(0), common.Hash{})
err := tester.sync("peer1", hashes[0])
if err != nil {
t.Error("download error", err)
}
inqueue := len(tester.downloader.queue.blockCache)
if inqueue != targetBlocks {
t.Error("expected", targetBlocks, "have", inqueue)
}
}
func TestTaking(t *testing.T) {
minDesiredPeerCount = 4
blockTtl = 1 * time.Second
targetBlocks := 1000
hashes := createHashes(0, targetBlocks)
blocks := createBlocksFromHashes(hashes)
tester := newTester(t, hashes, blocks)
tester.newPeer("peer1", big.NewInt(10000), hashes[0])
tester.newPeer("peer2", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})
err := tester.sync("peer1", hashes[0])
if err != nil {
t.Error("download error", err)
}
bs := tester.downloader.TakeBlocks()
if len(bs) != targetBlocks {
t.Error("retrieved block mismatch: have %v, want %v", len(bs), targetBlocks)
}
}
func TestInactiveDownloader(t *testing.T) {
targetBlocks := 1000
hashes := createHashes(0, targetBlocks)
blocks := createBlocksFromHashSet(createHashSet(hashes))
tester := newTester(t, hashes, nil)
err := tester.downloader.DeliverHashes("bad peer 001", hashes)
if err != errNoSyncActive {
t.Error("expected no sync error, got", err)
}
err = tester.downloader.DeliverBlocks("bad peer 001", blocks)
if err != errNoSyncActive {
t.Error("expected no sync error, got", err)
}
}
func TestCancel(t *testing.T) {
minDesiredPeerCount = 4
blockTtl = 1 * time.Second
targetBlocks := 1000
hashes := createHashes(0, targetBlocks)
blocks := createBlocksFromHashes(hashes)
tester := newTester(t, hashes, blocks)
tester.newPeer("peer1", big.NewInt(10000), hashes[0])
err := tester.sync("peer1", hashes[0])
if err != nil {
t.Error("download error", err)
}
if !tester.downloader.Cancel() {
t.Error("cancel operation unsuccessfull")
}
hashSize, blockSize := tester.downloader.queue.Size()
if hashSize > 0 || blockSize > 0 {
t.Error("block (", blockSize, ") or hash (", hashSize, ") not 0")
}
}
func TestThrottling(t *testing.T) {
minDesiredPeerCount = 4
blockTtl = 1 * time.Second
targetBlocks := 16 * blockCacheLimit
hashes := createHashes(0, targetBlocks)
blocks := createBlocksFromHashes(hashes)
tester := newTester(t, hashes, blocks)
tester.newPeer("peer1", big.NewInt(10000), hashes[0])
tester.newPeer("peer2", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{})
tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{})
// Concurrently download and take the blocks
errc := make(chan error, 1)
go func() {
errc <- tester.sync("peer1", hashes[0])
}()
done := make(chan struct{})
took := []*types.Block{}
go func() {
for running := true; running; {
select {
case <-done:
running = false
default:
time.Sleep(time.Millisecond)
}
// Take a batch of blocks and accumulate
took = append(took, tester.downloader.TakeBlocks()...)
}
done <- struct{}{}
}()
// Synchronise the two threads and verify
err := <-errc
done <- struct{}{}
<-done
if err != nil {
t.Fatalf("failed to synchronise blocks: %v", err)
}
if len(took) != targetBlocks {
t.Fatalf("downloaded block mismatch: have %v, want %v", len(took), targetBlocks)
}
}
// 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) {
// Forge a single-link chain with a forged header
hashes := createHashes(0, 1)
blocks := createBlocksFromHashes(hashes)
forged := blocks[hashes[0]]
forged.ParentHeaderHash = unknownHash
// Try and sync with the malicious node and check that it fails
tester := newTester(t, hashes, blocks)
tester.newPeer("attack", big.NewInt(10000), hashes[0])
if err := tester.sync("attack", hashes[0]); 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].ParentHash()) {
t.Fatalf("tester knows about the unknown hash")
}
tester.downloader.Cancel()
// Reconstruct a valid chain, and try to synchronize with it
forged.ParentHeaderHash = knownHash
tester.newPeer("valid", big.NewInt(20000), hashes[0])
if err := tester.sync("valid", hashes[0]); 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].ParentHash()) {
t.Fatalf("tester doesn't know about the origin hash")
}
}
