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) } }