package routing import ( "bytes" "encoding/binary" "encoding/hex" "encoding/json" "errors" "io/ioutil" "math/big" "net" "os" "strings" "testing" "time" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwire" "github.com/roasbeef/btcd/btcec" "github.com/roasbeef/btcd/chaincfg/chainhash" "github.com/roasbeef/btcd/wire" "github.com/roasbeef/btcutil" prand "math/rand" ) const ( // basicGraphFilePath is the file path for a basic graph used within // the tests. The basic graph consists of 5 nodes with 5 channels // connecting them. basicGraphFilePath = "testdata/basic_graph.json" // excessiveHopsGraphFilePath is a file path which stores the JSON dump // of a graph which was previously triggering an erroneous excessive // hops error. The error has since been fixed, but a test case // exercising it is kept around to guard against regressions. excessiveHopsGraphFilePath = "testdata/excessive_hops.json" ) var ( randSource = prand.NewSource(time.Now().Unix()) randInts = prand.New(randSource) testSig = &btcec.Signature{ R: new(big.Int), S: new(big.Int), } _, _ = testSig.R.SetString("63724406601629180062774974542967536251589935445068131219452686511677818569431", 10) _, _ = testSig.S.SetString("18801056069249825825291287104931333862866033135609736119018462340006816851118", 10) testAuthProof = channeldb.ChannelAuthProof{ NodeSig1: testSig, NodeSig2: testSig, BitcoinSig1: testSig, BitcoinSig2: testSig, } ) // testGraph is the struct which corresponds to the JSON format used to encode // graphs within the files in the testdata directory. // // TODO(roasbeef): add test graph auto-generator type testGraph struct { Info []string `json:"info"` Nodes []testNode `json:"nodes"` Edges []testChan `json:"edges"` } // testNode represents a node within the test graph above. We skip certain // information such as the node's IP address as that information isn't needed // for our tests. type testNode struct { Source bool `json:"source"` PubKey string `json:"pubkey"` Alias string `json:"alias"` } // testChan represents the JSON version of a payment channel. This struct // matches the Json that's encoded under the "edges" key within the test graph. type testChan struct { Node1 string `json:"node_1"` Node2 string `json:"node_2"` ChannelID uint64 `json:"channel_id"` ChannelPoint string `json:"channel_point"` Flags uint16 `json:"flags"` Expiry uint16 `json:"expiry"` MinHTLC int64 `json:"min_htlc"` FeeBaseMsat int64 `json:"fee_base_msat"` FeeRate int64 `json:"fee_rate"` Capacity int64 `json:"capacity"` } // makeTestGraph creates a new instance of a channeldb.ChannelGraph for testing // purposes. A callback which cleans up the created temporary directories is // also returned and intended to be executed after the test completes. func makeTestGraph() (*channeldb.ChannelGraph, 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 { return nil, nil, err } cleanUp := func() { cdb.Close() os.RemoveAll(tempDirName) } return cdb.ChannelGraph(), cleanUp, nil } // aliasMap is a map from a node's alias to its public key. This type is // provided in order to allow easily look up from the human rememberable alias // to an exact node's public key. type aliasMap map[string]*btcec.PublicKey // parseTestGraph returns a fully populated ChannelGraph given a path to a JSON // file which encodes a test graph. func parseTestGraph(path string) (*channeldb.ChannelGraph, func(), aliasMap, error) { graphJSON, err := ioutil.ReadFile(path) if err != nil { return nil, nil, nil, err } // First unmarshal the JSON graph into an instance of the testGraph // struct. Using the struct tags created above in the struct, the JSON // will be properly parsed into the struct above. var g testGraph if err := json.Unmarshal(graphJSON, &g); err != nil { return nil, nil, nil, err } // We'll use this fake address for the IP address of all the nodes in // our tests. This value isn't needed for path finding so it doesn't // need to be unique. var testAddrs []net.Addr testAddr, err := net.ResolveTCPAddr("tcp", "192.0.0.1:8888") if err != nil { return nil, nil, nil, err } testAddrs = append(testAddrs, testAddr) // Next, create a temporary graph database for usage within the test. graph, cleanUp, err := makeTestGraph() if err != nil { return nil, nil, nil, err } aliasMap := make(map[string]*btcec.PublicKey) var source *channeldb.LightningNode // First we insert all the nodes within the graph as vertexes. for _, node := range g.Nodes { pubBytes, err := hex.DecodeString(node.PubKey) if err != nil { return nil, nil, nil, err } pub, err := btcec.ParsePubKey(pubBytes, btcec.S256()) if err != nil { return nil, nil, nil, err } dbNode := &channeldb.LightningNode{ HaveNodeAnnouncement: true, AuthSig: testSig, LastUpdate: time.Now(), Addresses: testAddrs, PubKey: pub, Alias: node.Alias, Features: testFeatures, } // We require all aliases within the graph to be unique for our // tests. if _, ok := aliasMap[node.Alias]; ok { return nil, nil, nil, errors.New("aliases for nodes " + "must be unique!") } // If the alias is unique, then add the node to the // alias map for easy lookup. aliasMap[node.Alias] = pub // If the node is tagged as the source, then we create a // pointer to is so we can mark the source in the graph // properly. if node.Source { // If we come across a node that's marked as the // source, and we've already set the source in a prior // iteration, then the JSON has an error as only ONE // node can be the source in the graph. if source != nil { return nil, nil, nil, errors.New("JSON is invalid " + "multiple nodes are tagged as the source") } source = dbNode } // With the node fully parsed, add it as a vertex within the // graph. if err := graph.AddLightningNode(dbNode); err != nil { return nil, nil, nil, err } } if source != nil { // Set the selected source node if err := graph.SetSourceNode(source); err != nil { return nil, nil, nil, err } } // With all the vertexes inserted, we can now insert the edges into the // test graph. for _, edge := range g.Edges { node1Bytes, err := hex.DecodeString(edge.Node1) if err != nil { return nil, nil, nil, err } node1Pub, err := btcec.ParsePubKey(node1Bytes, btcec.S256()) if err != nil { return nil, nil, nil, err } node2Bytes, err := hex.DecodeString(edge.Node2) if err != nil { return nil, nil, nil, err } node2Pub, err := btcec.ParsePubKey(node2Bytes, btcec.S256()) if err != nil { return nil, nil, nil, err } fundingTXID := strings.Split(edge.ChannelPoint, ":")[0] txidBytes, err := chainhash.NewHashFromStr(fundingTXID) if err != nil { return nil, nil, nil, err } fundingPoint := wire.OutPoint{ Hash: *txidBytes, Index: 0, } // We first insert the existence of the edge between the two // nodes. edgeInfo := channeldb.ChannelEdgeInfo{ ChannelID: edge.ChannelID, NodeKey1: node1Pub, NodeKey2: node2Pub, BitcoinKey1: node1Pub, BitcoinKey2: node2Pub, AuthProof: &testAuthProof, ChannelPoint: fundingPoint, Capacity: btcutil.Amount(edge.Capacity), } err = graph.AddChannelEdge(&edgeInfo) if err != nil && err != channeldb.ErrEdgeAlreadyExist { return nil, nil, nil, err } edgePolicy := &channeldb.ChannelEdgePolicy{ Signature: testSig, Flags: edge.Flags, ChannelID: edge.ChannelID, LastUpdate: time.Now(), TimeLockDelta: edge.Expiry, MinHTLC: lnwire.MilliSatoshi(edge.MinHTLC), FeeBaseMSat: lnwire.MilliSatoshi(edge.FeeBaseMsat), FeeProportionalMillionths: lnwire.MilliSatoshi(edge.FeeRate), } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, nil, nil, err } } return graph, cleanUp, aliasMap, nil } func TestBasicGraphPathFinding(t *testing.T) { t.Parallel() graph, cleanUp, aliases, err := parseTestGraph(basicGraphFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } sourceVertex := newVertex(sourceNode.PubKey) ignoredEdges := make(map[uint64]struct{}) ignoredVertexes := make(map[vertex]struct{}) // With the test graph loaded, we'll test some basic path finding using // the pre-generated graph. Consult the testdata/basic_graph.json file // to follow along with the assumptions we'll use to test the path // finding. const startingHeight = 100 paymentAmt := lnwire.NewMSatFromSatoshis(100) target := aliases["sophon"] path, err := findPath(nil, graph, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute(paymentAmt, sourceVertex, path, startingHeight) if err != nil { t.Fatalf("unable to create path: %v", err) } // The length of the route selected should be of exactly length two. if len(route.Hops) != 2 { t.Fatalf("route is of incorrect length, expected %v got %v", 2, len(route.Hops)) } // As each hop only decrements a single block from the time-lock, the // total time lock value should two more than our starting block // height. if route.TotalTimeLock != 102 { t.Fatalf("expected time lock of %v, instead have %v", 2, route.TotalTimeLock) } // The first hop in the path should be an edge from roasbeef to goku. if !route.Hops[0].Channel.Node.PubKey.IsEqual(aliases["songoku"]) { t.Fatalf("first hop should be goku, is instead: %v", route.Hops[0].Channel.Node.Alias) } // The second hop should be from goku to sophon. if !route.Hops[1].Channel.Node.PubKey.IsEqual(aliases["sophon"]) { t.Fatalf("second hop should be sophon, is instead: %v", route.Hops[0].Channel.Node.Alias) } // Next, we'll assert that the "next hop" field in each route payload // properly points to the channel ID that the HTLC should be forwarded // along. hopPayloads := route.ToHopPayloads() if len(hopPayloads) != 2 { t.Fatalf("incorrect number of hop payloads: expected %v, got %v", 2, len(hopPayloads)) } // The first hop should point to the second hop. var expectedHop [8]byte binary.BigEndian.PutUint64(expectedHop[:], route.Hops[1].Channel.ChannelID) if !bytes.Equal(hopPayloads[0].NextAddress[:], expectedHop[:]) { t.Fatalf("first hop has incorrect next hop: expected %x, got %x", expectedHop[:], hopPayloads[0].NextAddress) } // The second hop should have a next hop value of all zeroes in order // to indicate it's the exit hop. var exitHop [8]byte if !bytes.Equal(hopPayloads[1].NextAddress[:], exitHop[:]) { t.Fatalf("first hop has incorrect next hop: expected %x, got %x", exitHop[:], hopPayloads[0].NextAddress) } // We'll also assert that the outgoing CLTV value for each hop was set // accordingly. if route.Hops[0].OutgoingTimeLock != 101 { t.Fatalf("expected outgoing time-lock of %v, instead have %v", 1, route.Hops[0].OutgoingTimeLock) } if route.Hops[1].OutgoingTimeLock != 101 { t.Fatalf("outgoing time-lock for final hop is incorrect: "+ "expected %v, got %v", 1, route.Hops[1].OutgoingTimeLock) } // Additionally, we'll ensure that the amount to forward, and fees // computed for each hop are correct. firstHopFee := route.Hops[0].Channel.FeeBaseMSat if route.TotalAmount != paymentAmt+firstHopFee { t.Fatalf("first hop forwarding amount incorrect: expected %v, got %v", paymentAmt+firstHopFee, route.Hops[0].AmtToForward) } if route.Hops[0].Fee != firstHopFee { t.Fatalf("first hop fee incorrect: expected %v, got %v", firstHopFee, route.Hops[0].Fee) } if route.Hops[1].AmtToForward != paymentAmt { t.Fatalf("second hop forwarding amount incorrect: expected %v, got %v", paymentAmt+firstHopFee, route.Hops[0].AmtToForward) } if route.Hops[1].Fee != 0 { t.Fatalf("second hop fee incorrect: expected %v, got %v", 0, route.Hops[1].Fee) } // Next, attempt to query for a path to Luo Ji for 100 satoshis, there // exist two possible paths in the graph, but the shorter (1 hop) path // should be selected. target = aliases["luoji"] path, err = findPath(nil, graph, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt) if err != nil { t.Fatalf("unable to find route: %v", err) } route, err = newRoute(paymentAmt, sourceVertex, path, startingHeight) if err != nil { t.Fatalf("unable to create path: %v", err) } // The length of the path should be exactly one hop as it's the // "shortest" known path in the graph. if len(route.Hops) != 1 { t.Fatalf("shortest path not selected, should be of length 1, "+ "is instead: %v", len(route.Hops)) } // As we have a direct path, the total time lock value should be // exactly the current block height plus one. if route.TotalTimeLock != 101 { t.Fatalf("expected time lock of %v, instead have %v", 1, route.TotalTimeLock) } // Additionally, since this is a single-hop payment, we shouldn't have // to pay any fees in total, so the total amount should be the payment // amount. if route.TotalAmount != paymentAmt { t.Fatalf("incorrect total amount, expected %v got %v", paymentAmt, route.TotalAmount) } } func TestKShortestPathFinding(t *testing.T) { t.Parallel() graph, cleanUp, aliases, err := parseTestGraph(basicGraphFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // In this test we'd like to ensure that our algoirthm to find the // k-shortest paths from a given source node to any destination node // works as exepcted. // In our basic_graph.json, there exist two paths from roasbeef to luo // ji. Our algorithm should properly find both paths, and also rank // them in order of their total "distance". paymentAmt := lnwire.NewMSatFromSatoshis(100) target := aliases["luoji"] paths, err := findPaths(nil, graph, sourceNode, target, paymentAmt) if err != nil { t.Fatalf("unable to find paths between roasbeef and "+ "luo ji: %v", err) } // The algorithm should've found two paths from roasbeef to luo ji. if len(paths) != 2 { t.Fatalf("two path shouldn't been found, instead %v were", len(paths)) } // Additinoally, the total hop length of the first path returned should // be _less_ than that of the second path returned. if len(paths[0]) > len(paths[1]) { t.Fatalf("paths found not ordered properly") } // Finally, we'll assert the exact expected ordering of both paths // found. assertExpectedPath := func(path []*ChannelHop, nodeAliases ...string) { for i, hop := range path { if hop.Node.Alias != nodeAliases[i] { t.Fatalf("expected %v to be pos #%v in hop, "+ "instead %v was", nodeAliases[i], i, hop.Node.Alias) } } } // The first route should be a direct route to luo ji. assertExpectedPath(paths[0], "roasbeef", "luoji") // The second route should be a route to luo ji via satoshi. assertExpectedPath(paths[1], "roasbeef", "satoshi", "luoji") } func TestNewRoutePathTooLong(t *testing.T) { t.Parallel() // Ensure that potential paths which are over the maximum hop-limit are // rejected. graph, cleanUp, aliases, err := parseTestGraph(excessiveHopsGraphFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } ignoredEdges := make(map[uint64]struct{}) ignoredVertexes := make(map[vertex]struct{}) paymentAmt := lnwire.NewMSatFromSatoshis(100) // We start by confirminig that routing a payment 20 hops away is possible. // Alice should be able to find a valid route to ursula. target := aliases["ursula"] _, err = findPath(nil, graph, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt) if err != nil { t.Fatalf("path should have been found") } // Vincent is 21 hops away from Alice, and thus no valid route should be // presented to Alice. target = aliases["vincent"] path, err := findPath(nil, graph, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt) if err == nil { t.Fatalf("should not have been able to find path, supposed to be "+ "greater than 20 hops, found route with %v hops", len(path)) } } func TestPathNotAvailable(t *testing.T) { t.Parallel() graph, cleanUp, _, err := parseTestGraph(basicGraphFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } ignoredEdges := make(map[uint64]struct{}) ignoredVertexes := make(map[vertex]struct{}) // With the test graph loaded, we'll test that queries for target that // are either unreachable within the graph, or unknown result in an // error. unknownNodeStr := "03dd46ff29a6941b4a2607525b043ec9b020b3f318a1bf281536fd7011ec59c882" unknownNodeBytes, err := hex.DecodeString(unknownNodeStr) if err != nil { t.Fatalf("unable to parse bytes: %v", err) } unknownNode, err := btcec.ParsePubKey(unknownNodeBytes, btcec.S256()) if err != nil { t.Fatalf("unable to parse pubkey: %v", err) } _, err = findPath(nil, graph, sourceNode, unknownNode, ignoredVertexes, ignoredEdges, 100) if !IsError(err, ErrNoPathFound) { t.Fatalf("path shouldn't have been found: %v", err) } } func TestPathInsufficientCapacity(t *testing.T) { t.Parallel() graph, cleanUp, aliases, err := parseTestGraph(basicGraphFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } ignoredEdges := make(map[uint64]struct{}) ignoredVertexes := make(map[vertex]struct{}) // Next, test that attempting to find a path in which the current // channel graph cannot support due to insufficient capacity triggers // an error. // To test his we'll attempt to make a payment of 1 BTC, or 100 million // satoshis. The largest channel in the basic graph is of size 100k // satoshis, so we shouldn't be able to find a path to sophon even // though we have a 2-hop link. target := aliases["sophon"] const payAmt = btcutil.SatoshiPerBitcoin _, err = findPath(nil, graph, sourceNode, target, ignoredVertexes, ignoredEdges, payAmt) if !IsError(err, ErrNoPathFound) { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } func TestPathInsufficientCapacityWithFee(t *testing.T) { t.Parallel() // TODO(roasbeef): encode live graph to json // TODO(roasbeef): need to add a case, or modify the fee ratio for one // to ensure that has going forward, but when fees are applied doesn't // work } // TODO(roasbeef): more time-lock calvulation tests