package htlcswitch import ( "bytes" "crypto/sha256" "encoding/binary" "fmt" "io" "io/ioutil" "net" "os" "sync" "sync/atomic" "testing" "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/wire" "github.com/go-errors/errors" sphinx "github.com/lightningnetwork/lightning-onion" "github.com/lightningnetwork/lnd/chainntnfs" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/clock" "github.com/lightningnetwork/lnd/contractcourt" "github.com/lightningnetwork/lnd/htlcswitch/hop" "github.com/lightningnetwork/lnd/invoices" "github.com/lightningnetwork/lnd/lnpeer" "github.com/lightningnetwork/lnd/lntest/mock" "github.com/lightningnetwork/lnd/lntypes" "github.com/lightningnetwork/lnd/lnwallet/chainfee" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/ticker" ) type mockPreimageCache struct { sync.Mutex preimageMap map[lntypes.Hash]lntypes.Preimage } func newMockPreimageCache() *mockPreimageCache { return &mockPreimageCache{ preimageMap: make(map[lntypes.Hash]lntypes.Preimage), } } func (m *mockPreimageCache) LookupPreimage( hash lntypes.Hash) (lntypes.Preimage, bool) { m.Lock() defer m.Unlock() p, ok := m.preimageMap[hash] return p, ok } func (m *mockPreimageCache) AddPreimages(preimages ...lntypes.Preimage) error { m.Lock() defer m.Unlock() for _, preimage := range preimages { m.preimageMap[preimage.Hash()] = preimage } return nil } func (m *mockPreimageCache) SubscribeUpdates() *contractcourt.WitnessSubscription { return nil } type mockFeeEstimator struct { byteFeeIn chan chainfee.SatPerKWeight quit chan struct{} } func (m *mockFeeEstimator) EstimateFeePerKW( numBlocks uint32) (chainfee.SatPerKWeight, error) { select { case feeRate := <-m.byteFeeIn: return feeRate, nil case <-m.quit: return 0, fmt.Errorf("exiting") } } func (m *mockFeeEstimator) RelayFeePerKW() chainfee.SatPerKWeight { return 1e3 } func (m *mockFeeEstimator) Start() error { return nil } func (m *mockFeeEstimator) Stop() error { close(m.quit) return nil } var _ chainfee.Estimator = (*mockFeeEstimator)(nil) type mockForwardingLog struct { sync.Mutex events map[time.Time]channeldb.ForwardingEvent } func (m *mockForwardingLog) AddForwardingEvents(events []channeldb.ForwardingEvent) error { m.Lock() defer m.Unlock() for _, event := range events { m.events[event.Timestamp] = event } return nil } type mockServer struct { started int32 // To be used atomically. shutdown int32 // To be used atomically. wg sync.WaitGroup quit chan struct{} t testing.TB name string messages chan lnwire.Message id [33]byte htlcSwitch *Switch registry *mockInvoiceRegistry pCache *mockPreimageCache interceptorFuncs []messageInterceptor } var _ lnpeer.Peer = (*mockServer)(nil) func initDB() (*channeldb.DB, error) { tempPath, err := ioutil.TempDir("", "switchdb") if err != nil { return nil, err } db, err := channeldb.Open(tempPath) if err != nil { return nil, err } return db, err } func initSwitchWithDB(startingHeight uint32, db *channeldb.DB) (*Switch, error) { var err error if db == nil { db, err = initDB() if err != nil { return nil, err } } cfg := Config{ DB: db, SwitchPackager: channeldb.NewSwitchPackager(), FwdingLog: &mockForwardingLog{ events: make(map[time.Time]channeldb.ForwardingEvent), }, FetchLastChannelUpdate: func(lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) { return nil, nil }, Notifier: &mock.ChainNotifier{ SpendChan: make(chan *chainntnfs.SpendDetail), EpochChan: make(chan *chainntnfs.BlockEpoch), ConfChan: make(chan *chainntnfs.TxConfirmation), }, FwdEventTicker: ticker.NewForce(DefaultFwdEventInterval), LogEventTicker: ticker.NewForce(DefaultLogInterval), AckEventTicker: ticker.NewForce(DefaultAckInterval), HtlcNotifier: &mockHTLCNotifier{}, Clock: clock.NewDefaultClock(), HTLCExpiry: time.Hour, } return New(cfg, startingHeight) } func newMockServer(t testing.TB, name string, startingHeight uint32, db *channeldb.DB, defaultDelta uint32) (*mockServer, error) { var id [33]byte h := sha256.Sum256([]byte(name)) copy(id[:], h[:]) pCache := newMockPreimageCache() htlcSwitch, err := initSwitchWithDB(startingHeight, db) if err != nil { return nil, err } registry := newMockRegistry(defaultDelta) return &mockServer{ t: t, id: id, name: name, messages: make(chan lnwire.Message, 3000), quit: make(chan struct{}), registry: registry, htlcSwitch: htlcSwitch, pCache: pCache, interceptorFuncs: make([]messageInterceptor, 0), }, nil } func (s *mockServer) Start() error { if !atomic.CompareAndSwapInt32(&s.started, 0, 1) { return errors.New("mock server already started") } if err := s.htlcSwitch.Start(); err != nil { return err } s.wg.Add(1) go func() { defer s.wg.Done() defer func() { s.htlcSwitch.Stop() }() for { select { case msg := <-s.messages: var shouldSkip bool for _, interceptor := range s.interceptorFuncs { skip, err := interceptor(msg) if err != nil { s.t.Fatalf("%v: error in the "+ "interceptor: %v", s.name, err) return } shouldSkip = shouldSkip || skip } if shouldSkip { continue } if err := s.readHandler(msg); err != nil { s.t.Fatal(err) return } case <-s.quit: return } } }() return nil } func (s *mockServer) QuitSignal() <-chan struct{} { return s.quit } // mockHopIterator represents the test version of hop iterator which instead // of encrypting the path in onion blob just stores the path as a list of hops. type mockHopIterator struct { hops []*hop.Payload } func newMockHopIterator(hops ...*hop.Payload) hop.Iterator { return &mockHopIterator{hops: hops} } func (r *mockHopIterator) HopPayload() (*hop.Payload, error) { h := r.hops[0] r.hops = r.hops[1:] return h, nil } func (r *mockHopIterator) ExtraOnionBlob() []byte { return nil } func (r *mockHopIterator) ExtractErrorEncrypter( extracter hop.ErrorEncrypterExtracter) (hop.ErrorEncrypter, lnwire.FailCode) { return extracter(nil) } func (r *mockHopIterator) EncodeNextHop(w io.Writer) error { var hopLength [4]byte binary.BigEndian.PutUint32(hopLength[:], uint32(len(r.hops))) if _, err := w.Write(hopLength[:]); err != nil { return err } for _, hop := range r.hops { fwdInfo := hop.ForwardingInfo() if err := encodeFwdInfo(w, &fwdInfo); err != nil { return err } } return nil } func encodeFwdInfo(w io.Writer, f *hop.ForwardingInfo) error { if _, err := w.Write([]byte{byte(f.Network)}); err != nil { return err } if err := binary.Write(w, binary.BigEndian, f.NextHop); err != nil { return err } if err := binary.Write(w, binary.BigEndian, f.AmountToForward); err != nil { return err } if err := binary.Write(w, binary.BigEndian, f.OutgoingCTLV); err != nil { return err } return nil } var _ hop.Iterator = (*mockHopIterator)(nil) // mockObfuscator mock implementation of the failure obfuscator which only // encodes the failure and do not makes any onion obfuscation. type mockObfuscator struct { ogPacket *sphinx.OnionPacket failure lnwire.FailureMessage } // NewMockObfuscator initializes a dummy mockObfuscator used for testing. func NewMockObfuscator() hop.ErrorEncrypter { return &mockObfuscator{} } func (o *mockObfuscator) OnionPacket() *sphinx.OnionPacket { return o.ogPacket } func (o *mockObfuscator) Type() hop.EncrypterType { return hop.EncrypterTypeMock } func (o *mockObfuscator) Encode(w io.Writer) error { return nil } func (o *mockObfuscator) Decode(r io.Reader) error { return nil } func (o *mockObfuscator) Reextract( extracter hop.ErrorEncrypterExtracter) error { return nil } func (o *mockObfuscator) EncryptFirstHop(failure lnwire.FailureMessage) ( lnwire.OpaqueReason, error) { o.failure = failure var b bytes.Buffer if err := lnwire.EncodeFailure(&b, failure, 0); err != nil { return nil, err } return b.Bytes(), nil } func (o *mockObfuscator) IntermediateEncrypt(reason lnwire.OpaqueReason) lnwire.OpaqueReason { return reason } func (o *mockObfuscator) EncryptMalformedError(reason lnwire.OpaqueReason) lnwire.OpaqueReason { return reason } // mockDeobfuscator mock implementation of the failure deobfuscator which // only decodes the failure do not makes any onion obfuscation. type mockDeobfuscator struct{} func newMockDeobfuscator() ErrorDecrypter { return &mockDeobfuscator{} } func (o *mockDeobfuscator) DecryptError(reason lnwire.OpaqueReason) (*ForwardingError, error) { r := bytes.NewReader(reason) failure, err := lnwire.DecodeFailure(r, 0) if err != nil { return nil, err } return NewForwardingError(failure, 1), nil } var _ ErrorDecrypter = (*mockDeobfuscator)(nil) // mockIteratorDecoder test version of hop iterator decoder which decodes the // encoded array of hops. type mockIteratorDecoder struct { mu sync.RWMutex responses map[[32]byte][]hop.DecodeHopIteratorResponse decodeFail bool } func newMockIteratorDecoder() *mockIteratorDecoder { return &mockIteratorDecoder{ responses: make(map[[32]byte][]hop.DecodeHopIteratorResponse), } } func (p *mockIteratorDecoder) DecodeHopIterator(r io.Reader, rHash []byte, cltv uint32) (hop.Iterator, lnwire.FailCode) { var b [4]byte _, err := r.Read(b[:]) if err != nil { return nil, lnwire.CodeTemporaryChannelFailure } hopLength := binary.BigEndian.Uint32(b[:]) hops := make([]*hop.Payload, hopLength) for i := uint32(0); i < hopLength; i++ { var f hop.ForwardingInfo if err := decodeFwdInfo(r, &f); err != nil { return nil, lnwire.CodeTemporaryChannelFailure } var nextHopBytes [8]byte binary.BigEndian.PutUint64(nextHopBytes[:], f.NextHop.ToUint64()) hops[i] = hop.NewLegacyPayload(&sphinx.HopData{ Realm: [1]byte{}, // hop.BitcoinNetwork NextAddress: nextHopBytes, ForwardAmount: uint64(f.AmountToForward), OutgoingCltv: f.OutgoingCTLV, }) } return newMockHopIterator(hops...), lnwire.CodeNone } func (p *mockIteratorDecoder) DecodeHopIterators(id []byte, reqs []hop.DecodeHopIteratorRequest) ( []hop.DecodeHopIteratorResponse, error) { idHash := sha256.Sum256(id) p.mu.RLock() if resps, ok := p.responses[idHash]; ok { p.mu.RUnlock() return resps, nil } p.mu.RUnlock() batchSize := len(reqs) resps := make([]hop.DecodeHopIteratorResponse, 0, batchSize) for _, req := range reqs { iterator, failcode := p.DecodeHopIterator( req.OnionReader, req.RHash, req.IncomingCltv, ) if p.decodeFail { failcode = lnwire.CodeTemporaryChannelFailure } resp := hop.DecodeHopIteratorResponse{ HopIterator: iterator, FailCode: failcode, } resps = append(resps, resp) } p.mu.Lock() p.responses[idHash] = resps p.mu.Unlock() return resps, nil } func decodeFwdInfo(r io.Reader, f *hop.ForwardingInfo) error { var net [1]byte if _, err := r.Read(net[:]); err != nil { return err } f.Network = hop.Network(net[0]) if err := binary.Read(r, binary.BigEndian, &f.NextHop); err != nil { return err } if err := binary.Read(r, binary.BigEndian, &f.AmountToForward); err != nil { return err } if err := binary.Read(r, binary.BigEndian, &f.OutgoingCTLV); err != nil { return err } return nil } // messageInterceptor is function that handles the incoming peer messages and // may decide should the peer skip the message or not. type messageInterceptor func(m lnwire.Message) (bool, error) // Record is used to set the function which will be triggered when new // lnwire message was received. func (s *mockServer) intersect(f messageInterceptor) { s.interceptorFuncs = append(s.interceptorFuncs, f) } func (s *mockServer) SendMessage(sync bool, msgs ...lnwire.Message) error { for _, msg := range msgs { select { case s.messages <- msg: case <-s.quit: return errors.New("server is stopped") } } return nil } func (s *mockServer) SendMessageLazy(sync bool, msgs ...lnwire.Message) error { panic("not implemented") } func (s *mockServer) readHandler(message lnwire.Message) error { var targetChan lnwire.ChannelID switch msg := message.(type) { case *lnwire.UpdateAddHTLC: targetChan = msg.ChanID case *lnwire.UpdateFulfillHTLC: targetChan = msg.ChanID case *lnwire.UpdateFailHTLC: targetChan = msg.ChanID case *lnwire.UpdateFailMalformedHTLC: targetChan = msg.ChanID case *lnwire.RevokeAndAck: targetChan = msg.ChanID case *lnwire.CommitSig: targetChan = msg.ChanID case *lnwire.FundingLocked: // Ignore return nil case *lnwire.ChannelReestablish: targetChan = msg.ChanID case *lnwire.UpdateFee: targetChan = msg.ChanID default: return fmt.Errorf("unknown message type: %T", msg) } // Dispatch the commitment update message to the proper channel link // dedicated to this channel. If the link is not found, we will discard // the message. link, err := s.htlcSwitch.GetLink(targetChan) if err != nil { return nil } // Create goroutine for this, in order to be able to properly stop // the server when handler stacked (server unavailable) link.HandleChannelUpdate(message) return nil } func (s *mockServer) PubKey() [33]byte { return s.id } func (s *mockServer) IdentityKey() *btcec.PublicKey { pubkey, _ := btcec.ParsePubKey(s.id[:], btcec.S256()) return pubkey } func (s *mockServer) Address() net.Addr { return nil } func (s *mockServer) AddNewChannel(channel *channeldb.OpenChannel, cancel <-chan struct{}) error { return nil } func (s *mockServer) WipeChannel(*wire.OutPoint) {} func (s *mockServer) LocalFeatures() *lnwire.FeatureVector { return nil } func (s *mockServer) RemoteFeatures() *lnwire.FeatureVector { return nil } func (s *mockServer) Stop() error { if !atomic.CompareAndSwapInt32(&s.shutdown, 0, 1) { return nil } close(s.quit) s.wg.Wait() return nil } func (s *mockServer) String() string { return s.name } type mockChannelLink struct { htlcSwitch *Switch shortChanID lnwire.ShortChannelID chanID lnwire.ChannelID peer lnpeer.Peer mailBox MailBox packets chan *htlcPacket eligible bool htlcID uint64 checkHtlcTransitResult *LinkError checkHtlcForwardResult *LinkError } // completeCircuit is a helper method for adding the finalized payment circuit // to the switch's circuit map. In testing, this should be executed after // receiving an htlc from the downstream packets channel. func (f *mockChannelLink) completeCircuit(pkt *htlcPacket) error { switch htlc := pkt.htlc.(type) { case *lnwire.UpdateAddHTLC: pkt.outgoingChanID = f.shortChanID pkt.outgoingHTLCID = f.htlcID htlc.ID = f.htlcID keystone := Keystone{pkt.inKey(), pkt.outKey()} if err := f.htlcSwitch.openCircuits(keystone); err != nil { return err } f.htlcID++ case *lnwire.UpdateFulfillHTLC, *lnwire.UpdateFailHTLC: err := f.htlcSwitch.teardownCircuit(pkt) if err != nil { return err } } f.mailBox.AckPacket(pkt.inKey()) return nil } func (f *mockChannelLink) deleteCircuit(pkt *htlcPacket) error { return f.htlcSwitch.deleteCircuits(pkt.inKey()) } func newMockChannelLink(htlcSwitch *Switch, chanID lnwire.ChannelID, shortChanID lnwire.ShortChannelID, peer lnpeer.Peer, eligible bool, ) *mockChannelLink { return &mockChannelLink{ htlcSwitch: htlcSwitch, chanID: chanID, shortChanID: shortChanID, peer: peer, eligible: eligible, } } func (f *mockChannelLink) HandleSwitchPacket(pkt *htlcPacket) error { f.mailBox.AddPacket(pkt) return nil } func (f *mockChannelLink) HandleLocalAddPacket(pkt *htlcPacket) error { _ = f.mailBox.AddPacket(pkt) return nil } func (f *mockChannelLink) HandleChannelUpdate(lnwire.Message) { } func (f *mockChannelLink) UpdateForwardingPolicy(_ ForwardingPolicy) { } func (f *mockChannelLink) CheckHtlcForward([32]byte, lnwire.MilliSatoshi, lnwire.MilliSatoshi, uint32, uint32, uint32) *LinkError { return f.checkHtlcForwardResult } func (f *mockChannelLink) CheckHtlcTransit(payHash [32]byte, amt lnwire.MilliSatoshi, timeout uint32, heightNow uint32) *LinkError { return f.checkHtlcTransitResult } func (f *mockChannelLink) Stats() (uint64, lnwire.MilliSatoshi, lnwire.MilliSatoshi) { return 0, 0, 0 } func (f *mockChannelLink) AttachMailBox(mailBox MailBox) { f.mailBox = mailBox f.packets = mailBox.PacketOutBox() } func (f *mockChannelLink) Start() error { f.mailBox.ResetMessages() f.mailBox.ResetPackets() return nil } func (f *mockChannelLink) ChanID() lnwire.ChannelID { return f.chanID } func (f *mockChannelLink) ShortChanID() lnwire.ShortChannelID { return f.shortChanID } func (f *mockChannelLink) Bandwidth() lnwire.MilliSatoshi { return 99999999 } func (f *mockChannelLink) Peer() lnpeer.Peer { return f.peer } func (f *mockChannelLink) ChannelPoint() *wire.OutPoint { return &wire.OutPoint{} } func (f *mockChannelLink) Stop() {} func (f *mockChannelLink) EligibleToForward() bool { return f.eligible } func (f *mockChannelLink) setLiveShortChanID(sid lnwire.ShortChannelID) { f.shortChanID = sid } func (f *mockChannelLink) UpdateShortChanID() (lnwire.ShortChannelID, error) { f.eligible = true return f.shortChanID, nil } var _ ChannelLink = (*mockChannelLink)(nil) func newDB() (*channeldb.DB, func(), error) { // First, create a temporary directory to be used for the duration of // this test. tempDirName, err := ioutil.TempDir("", "channeldb") if err != nil { return nil, nil, err } // Next, create channeldb for the first time. cdb, err := channeldb.Open(tempDirName) if err != nil { os.RemoveAll(tempDirName) return nil, nil, err } cleanUp := func() { cdb.Close() os.RemoveAll(tempDirName) } return cdb, cleanUp, nil } const testInvoiceCltvExpiry = 6 type mockInvoiceRegistry struct { settleChan chan lntypes.Hash registry *invoices.InvoiceRegistry cleanup func() } func newMockRegistry(minDelta uint32) *mockInvoiceRegistry { cdb, cleanup, err := newDB() if err != nil { panic(err) } registry := invoices.NewRegistry( cdb, invoices.NewInvoiceExpiryWatcher(clock.NewDefaultClock()), &invoices.RegistryConfig{ FinalCltvRejectDelta: 5, }, ) registry.Start() return &mockInvoiceRegistry{ registry: registry, cleanup: cleanup, } } func (i *mockInvoiceRegistry) LookupInvoice(rHash lntypes.Hash) ( channeldb.Invoice, error) { return i.registry.LookupInvoice(rHash) } func (i *mockInvoiceRegistry) SettleHodlInvoice(preimage lntypes.Preimage) error { return i.registry.SettleHodlInvoice(preimage) } func (i *mockInvoiceRegistry) NotifyExitHopHtlc(rhash lntypes.Hash, amt lnwire.MilliSatoshi, expiry uint32, currentHeight int32, circuitKey channeldb.CircuitKey, hodlChan chan<- interface{}, payload invoices.Payload) (invoices.HtlcResolution, error) { event, err := i.registry.NotifyExitHopHtlc( rhash, amt, expiry, currentHeight, circuitKey, hodlChan, payload, ) if err != nil { return nil, err } if i.settleChan != nil { i.settleChan <- rhash } return event, nil } func (i *mockInvoiceRegistry) CancelInvoice(payHash lntypes.Hash) error { return i.registry.CancelInvoice(payHash) } func (i *mockInvoiceRegistry) AddInvoice(invoice channeldb.Invoice, paymentHash lntypes.Hash) error { _, err := i.registry.AddInvoice(&invoice, paymentHash) return err } func (i *mockInvoiceRegistry) HodlUnsubscribeAll(subscriber chan<- interface{}) { i.registry.HodlUnsubscribeAll(subscriber) } var _ InvoiceDatabase = (*mockInvoiceRegistry)(nil) type mockCircuitMap struct { lookup chan *PaymentCircuit } var _ CircuitMap = (*mockCircuitMap)(nil) func (m *mockCircuitMap) OpenCircuits(...Keystone) error { return nil } func (m *mockCircuitMap) TrimOpenCircuits(chanID lnwire.ShortChannelID, start uint64) error { return nil } func (m *mockCircuitMap) DeleteCircuits(inKeys ...CircuitKey) error { return nil } func (m *mockCircuitMap) CommitCircuits( circuit ...*PaymentCircuit) (*CircuitFwdActions, error) { return nil, nil } func (m *mockCircuitMap) CloseCircuit(outKey CircuitKey) (*PaymentCircuit, error) { return nil, nil } func (m *mockCircuitMap) FailCircuit(inKey CircuitKey) (*PaymentCircuit, error) { return nil, nil } func (m *mockCircuitMap) LookupCircuit(inKey CircuitKey) *PaymentCircuit { return <-m.lookup } func (m *mockCircuitMap) LookupOpenCircuit(outKey CircuitKey) *PaymentCircuit { return nil } func (m *mockCircuitMap) LookupByPaymentHash(hash [32]byte) []*PaymentCircuit { return nil } func (m *mockCircuitMap) NumPending() int { return 0 } func (m *mockCircuitMap) NumOpen() int { return 0 } type mockOnionErrorDecryptor struct { sourceIdx int message []byte err error } func (m *mockOnionErrorDecryptor) DecryptError(encryptedData []byte) ( *sphinx.DecryptedError, error) { return &sphinx.DecryptedError{ SenderIdx: m.sourceIdx, Message: m.message, }, m.err } var _ htlcNotifier = (*mockHTLCNotifier)(nil) type mockHTLCNotifier struct{} func (h *mockHTLCNotifier) NotifyForwardingEvent(key HtlcKey, info HtlcInfo, eventType HtlcEventType) { } func (h *mockHTLCNotifier) NotifyLinkFailEvent(key HtlcKey, info HtlcInfo, eventType HtlcEventType, linkErr *LinkError, incoming bool) { } func (h *mockHTLCNotifier) NotifyForwardingFailEvent(key HtlcKey, eventType HtlcEventType) { } func (h *mockHTLCNotifier) NotifySettleEvent(key HtlcKey, eventType HtlcEventType) { }