package routing import ( "bytes" "crypto/sha256" "encoding/binary" "encoding/hex" "encoding/json" "errors" "io/ioutil" "math" "math/big" "net" "os" "strings" "testing" "time" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcd/chaincfg/chainhash" "github.com/btcsuite/btcd/wire" "github.com/btcsuite/btcutil" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwire" 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" // specExampleFilePath is a file path which stores an example which // implementations will use in order to ensure that they're calculating // the payload for each hop in path properly. specExampleFilePath = "testdata/spec_example.json" // noFeeLimit is the maximum value of a payment through Lightning. We // can use this value to signal there is no fee limit since payments // should never be larger than this. noFeeLimit = lnwire.MilliSatoshi(math.MaxUint32) ) 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{ NodeSig1Bytes: testSig.Serialize(), NodeSig2Bytes: testSig.Serialize(), BitcoinSig1Bytes: testSig.Serialize(), BitcoinSig2Bytes: testSig.Serialize(), } ) // 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 memorable 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 } dbNode := &channeldb.LightningNode{ HaveNodeAnnouncement: true, AuthSigBytes: testSig.Serialize(), LastUpdate: time.Now(), Addresses: testAddrs, Alias: node.Alias, Features: testFeatures, } copy(dbNode.PubKeyBytes[:], pubBytes) // 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!") } pub, err := btcec.ParsePubKey(pubBytes, btcec.S256()) if err != nil { return nil, nil, nil, err } // 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 } node2Bytes, err := hex.DecodeString(edge.Node2) 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, AuthProof: &testAuthProof, ChannelPoint: fundingPoint, Capacity: btcutil.Amount(edge.Capacity), } copy(edgeInfo.NodeKey1Bytes[:], node1Bytes) copy(edgeInfo.NodeKey2Bytes[:], node2Bytes) copy(edgeInfo.BitcoinKey1Bytes[:], node1Bytes) copy(edgeInfo.BitcoinKey2Bytes[:], node2Bytes) err = graph.AddChannelEdge(&edgeInfo) if err != nil && err != channeldb.ErrEdgeAlreadyExist { return nil, nil, nil, err } edgePolicy := &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), Flags: lnwire.ChanUpdateFlag(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 } type testChannelPolicy struct { Expiry uint16 MinHTLC lnwire.MilliSatoshi FeeBaseMsat lnwire.MilliSatoshi FeeRate lnwire.MilliSatoshi } type testChannelEnd struct { Alias string testChannelPolicy } func defaultTestChannelEnd(alias string) *testChannelEnd { return &testChannelEnd{ Alias: alias, testChannelPolicy: testChannelPolicy{ Expiry: 144, MinHTLC: lnwire.MilliSatoshi(1000), FeeBaseMsat: lnwire.MilliSatoshi(1000), FeeRate: lnwire.MilliSatoshi(1), }, } } func symmetricTestChannel(alias1 string, alias2 string, capacity btcutil.Amount, policy *testChannelPolicy) *testChannel { return &testChannel{ Capacity: capacity, Node1: &testChannelEnd{ Alias: alias1, testChannelPolicy: *policy, }, Node2: &testChannelEnd{ Alias: alias2, testChannelPolicy: *policy, }, } } type testChannel struct { Node1 *testChannelEnd Node2 *testChannelEnd Capacity btcutil.Amount } // createTestGraph returns a fully populated ChannelGraph based on a set of // test channels. Additional required information like keys are derived in // a deterministical way and added to the channel graph. A list of nodes is // not required and derived from the channel data. The goal is to keep // instantiating a test channel graph as light weight as possible. func createTestGraph(testChannels []*testChannel) (*channeldb.ChannelGraph, func(), aliasMap, error) { // 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) nodeIndex := byte(0) addNodeWithAlias := func(alias string) (*channeldb.LightningNode, error) { keyBytes := make([]byte, 32) keyBytes = []byte{ 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, nodeIndex + 1, } _, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), keyBytes) dbNode := &channeldb.LightningNode{ HaveNodeAnnouncement: true, AuthSigBytes: testSig.Serialize(), LastUpdate: time.Now(), Addresses: testAddrs, Alias: alias, Features: testFeatures, } copy(dbNode.PubKeyBytes[:], pubKey.SerializeCompressed()) // With the node fully parsed, add it as a vertex within the // graph. if err := graph.AddLightningNode(dbNode); err != nil { return nil, err } aliasMap[alias] = pubKey nodeIndex++ return dbNode, nil } var source *channeldb.LightningNode if source, err = addNodeWithAlias("roasbeef"); err != nil { return nil, nil, nil, err } // Set the source node if err := graph.SetSourceNode(source); err != nil { return nil, nil, nil, err } channelID := uint64(0) for _, testChannel := range testChannels { for _, alias := range []string{ testChannel.Node1.Alias, testChannel.Node2.Alias} { _, exists := aliasMap[alias] if !exists { addNodeWithAlias(alias) } } var hash [sha256.Size]byte hash[len(hash)-1] = byte(channelID) fundingPoint := &wire.OutPoint{ Hash: chainhash.Hash(hash), Index: 0, } // We first insert the existence of the edge between the two // nodes. edgeInfo := channeldb.ChannelEdgeInfo{ ChannelID: channelID, AuthProof: &testAuthProof, ChannelPoint: *fundingPoint, Capacity: testChannel.Capacity, } node1Bytes := aliasMap[testChannel.Node1.Alias].SerializeCompressed() node2Bytes := aliasMap[testChannel.Node2.Alias].SerializeCompressed() copy(edgeInfo.NodeKey1Bytes[:], node1Bytes) copy(edgeInfo.NodeKey2Bytes[:], node2Bytes) copy(edgeInfo.BitcoinKey1Bytes[:], node1Bytes) copy(edgeInfo.BitcoinKey2Bytes[:], node2Bytes) err = graph.AddChannelEdge(&edgeInfo) if err != nil && err != channeldb.ErrEdgeAlreadyExist { return nil, nil, nil, err } edgePolicy := &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), Flags: lnwire.ChanUpdateFlag(0), ChannelID: channelID, LastUpdate: time.Now(), TimeLockDelta: testChannel.Node1.Expiry, MinHTLC: testChannel.Node1.MinHTLC, FeeBaseMSat: testChannel.Node1.FeeBaseMsat, FeeProportionalMillionths: testChannel.Node1.FeeRate, } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, nil, nil, err } edgePolicy = &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), Flags: lnwire.ChanUpdateFlag(lnwire.ChanUpdateDirection), ChannelID: channelID, LastUpdate: time.Now(), TimeLockDelta: testChannel.Node2.Expiry, MinHTLC: testChannel.Node2.MinHTLC, FeeBaseMSat: testChannel.Node2.FeeBaseMsat, FeeProportionalMillionths: testChannel.Node2.FeeRate, } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, nil, nil, err } channelID++ } return graph, cleanUp, aliasMap, nil } // TestFindLowestFeePath tests that out of two routes with identical total // time lock values, the route with the lowest total fee should be returned. // The fee rates are chosen such that the test failed on the previous edge // weight function where one of the terms was fee squared. func TestFindLowestFeePath(t *testing.T) { t.Parallel() // Set up a test graph with two paths from roasbeef to target. Both // paths have equal total time locks, but the path through b has lower // fees (700 compared to 800 for the path through a). testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "a", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, }), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, }), symmetricTestChannel("roasbeef", "b", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 100, MinHTLC: 1, }), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 600, MinHTLC: 1, }), } graph, cleanUp, aliases, err := createTestGraph(testChannels) 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 := Vertex(sourceNode.PubKeyBytes) ignoredEdges := make(map[uint64]struct{}) ignoredVertexes := make(map[Vertex]struct{}) const ( startingHeight = 100 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(100) target := aliases["target"] path, err := findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt, nil, ) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( paymentAmt, infinity, sourceVertex, path, startingHeight, finalHopCLTV) if err != nil { t.Fatalf("unable to create path: %v", err) } // Assert that the lowest fee route is returned. if !bytes.Equal(route.Hops[0].Channel.Node.PubKeyBytes[:], aliases["b"].SerializeCompressed()) { t.Fatalf("expected route to pass through b, "+ "but got a route through %v", route.Hops[0].Channel.Node.Alias) } } 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 := Vertex(sourceNode.PubKeyBytes) 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 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(100) target := aliases["sophon"] path, err := findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt, nil, ) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( paymentAmt, noFeeLimit, sourceVertex, path, startingHeight, finalHopCLTV, ) 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 !bytes.Equal(route.Hops[0].Channel.Node.PubKeyBytes[:], aliases["songoku"].SerializeCompressed()) { 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 !bytes.Equal(route.Hops[1].Channel.Node.PubKeyBytes[:], aliases["sophon"].SerializeCompressed()) { 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 := computeFee( paymentAmt, route.Hops[1].Channel.ChannelEdgePolicy, ) if route.Hops[0].Fee != firstHopFee { t.Fatalf("first hop fee incorrect: expected %v, got %v", firstHopFee, route.Hops[0].Fee) } if route.TotalAmount != paymentAmt+firstHopFee { t.Fatalf("first hop forwarding amount incorrect: expected %v, got %v", paymentAmt+firstHopFee, route.TotalAmount) } if route.Hops[1].Fee != 0 { t.Fatalf("first hop fee incorrect: expected %v, got %v", firstHopFee, 0) } if route.Hops[1].AmtToForward != paymentAmt { t.Fatalf("second hop forwarding amount incorrect: expected %v, got %v", paymentAmt+firstHopFee, route.Hops[1].AmtToForward) } // Finally, the next and prev hop maps should be properly set. // // The previous hop from goku should be the channel from roasbeef, and // the next hop should be the channel to sophon. gokuPrevChan, ok := route.prevHopChannel(aliases["songoku"]) if !ok { t.Fatalf("goku didn't have next chan but should have") } if gokuPrevChan.ChannelID != route.Hops[0].Channel.ChannelID { t.Fatalf("incorrect prev chan: expected %v, got %v", gokuPrevChan.ChannelID, route.Hops[0].Channel.ChannelID) } gokuNextChan, ok := route.nextHopChannel(aliases["songoku"]) if !ok { t.Fatalf("goku didn't have prev chan but should have") } if gokuNextChan.ChannelID != route.Hops[1].Channel.ChannelID { t.Fatalf("incorrect prev chan: expected %v, got %v", gokuNextChan.ChannelID, route.Hops[1].Channel.ChannelID) } // Sophon shouldn't have a next chan, but she should have a prev chan. if _, ok := route.nextHopChannel(aliases["sophon"]); ok { t.Fatalf("incorrect next hop map, no vertexes should " + "be after sophon") } sophonPrevEdge, ok := route.prevHopChannel(aliases["sophon"]) if !ok { t.Fatalf("sophon didn't have prev chan but should have") } if sophonPrevEdge.ChannelID != route.Hops[1].Channel.ChannelID { t.Fatalf("incorrect prev chan: expected %v, got %v", sophonPrevEdge.ChannelID, route.Hops[1].Channel.ChannelID) } // 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, nil, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt, nil, ) if err != nil { t.Fatalf("unable to find route: %v", err) } route, err = newRoute( paymentAmt, noFeeLimit, sourceVertex, path, startingHeight, finalHopCLTV, ) 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 TestPathFindingWithAdditionalEdges(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) } paymentAmt := lnwire.NewMSatFromSatoshis(100) // In this test, we'll test that we're able to find paths through // private channels when providing them as additional edges in our path // finding algorithm. To do so, we'll create a new node, doge, and // create a private channel between it and songoku. We'll then attempt // to find a path from our source node, roasbeef, to doge. dogePubKeyHex := "03dd46ff29a6941b4a2607525b043ec9b020b3f318a1bf281536fd7011ec59c882" dogePubKeyBytes, err := hex.DecodeString(dogePubKeyHex) if err != nil { t.Fatalf("unable to decode public key: %v", err) } dogePubKey, err := btcec.ParsePubKey(dogePubKeyBytes, btcec.S256()) if err != nil { t.Fatalf("unable to parse public key from bytes: %v", err) } doge := &channeldb.LightningNode{} doge.AddPubKey(dogePubKey) doge.Alias = "doge" // Create the channel edge going from songoku to doge and include it in // our map of additional edges. songokuToDoge := &channeldb.ChannelEdgePolicy{ Node: doge, ChannelID: 1337, FeeBaseMSat: 1, FeeProportionalMillionths: 1000, TimeLockDelta: 9, } additionalEdges := map[Vertex][]*channeldb.ChannelEdgePolicy{ NewVertex(aliases["songoku"]): {songokuToDoge}, } // We should now be able to find a path from roasbeef to doge. path, err := findPath( nil, graph, additionalEdges, sourceNode, dogePubKey, nil, nil, paymentAmt, nil, ) if err != nil { t.Fatalf("unable to find private path to doge: %v", err) } // The path should represent the following hops: // roasbeef -> songoku -> doge assertExpectedPath(t, path, "songoku", "doge") } 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 algorithm to find the // k-shortest paths from a given source node to any destination node // works as expected. // 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, 100, nil, ) if err != nil { t.Fatalf("unable to find paths between roasbeef and "+ "luo ji: %v", err) } // The algorithm should have 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)) } // Additionally, 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") } // The first route should be a direct route to luo ji. assertExpectedPath(t, paths[0], "roasbeef", "luoji") // The second route should be a route to luo ji via satoshi. assertExpectedPath(t, paths[1], "roasbeef", "satoshi", "luoji") } // TestNewRoute tests whether the construction of hop payloads by newRoute // is executed correctly. func TestNewRoute(t *testing.T) { var sourceKey [33]byte sourceVertex := Vertex(sourceKey) const ( startingHeight = 100 finalHopCLTV = 1 ) createHop := func(baseFee lnwire.MilliSatoshi, feeRate lnwire.MilliSatoshi, capacity btcutil.Amount, timeLockDelta uint16) *ChannelHop { return &ChannelHop{ ChannelEdgePolicy: &channeldb.ChannelEdgePolicy{ Node: &channeldb.LightningNode{}, FeeProportionalMillionths: feeRate, FeeBaseMSat: baseFee, TimeLockDelta: timeLockDelta, }, Capacity: capacity, } } testCases := []struct { // name identifies the test case in the test output. name string // hops is the list of hops (the route) that gets passed into // the call to newRoute. hops []*ChannelHop // paymentAmount is the amount that is send into the route // indicated by hops. paymentAmount lnwire.MilliSatoshi // expectedFees is a list of fees that every hop is expected // to charge for forwarding. expectedFees []lnwire.MilliSatoshi // expectedTimeLocks is a list of time lock values that every // hop is expected to specify in its outgoing HTLC. The time // lock values in this list are relative to the current block // height. expectedTimeLocks []uint32 // expectedTotalAmount is the total amount that is expected to // be returned from newRoute. This amount should include all // the fees to be paid to intermediate hops. expectedTotalAmount lnwire.MilliSatoshi // expectedTotalTimeLock is the time lock that is expected to // be returned from newRoute. This is the time lock that should // be specified in the HTLC that is sent by the source node. // expectedTotalTimeLock is relative to the current block height. expectedTotalTimeLock uint32 // expectError indicates whether the newRoute call is expected // to fail or succeed. expectError bool // expectedErrorCode indicates the expected error code when // expectError is true. expectedErrorCode errorCode }{ { // For a single hop payment, no fees are expected to be paid. name: "single hop", paymentAmount: 100000, hops: []*ChannelHop{ createHop(100, 1000, 1000, 10), }, expectedFees: []lnwire.MilliSatoshi{0}, expectedTimeLocks: []uint32{1}, expectedTotalAmount: 100000, expectedTotalTimeLock: 1, }, { // For a two hop payment, only the fee for the first hop // needs to be paid. The destination hop does not require // a fee to receive the payment. name: "two hop", paymentAmount: 100000, hops: []*ChannelHop{ createHop(0, 1000, 1000, 10), createHop(30, 1000, 1000, 5), }, expectedFees: []lnwire.MilliSatoshi{130, 0}, expectedTimeLocks: []uint32{1, 1}, expectedTotalAmount: 100130, expectedTotalTimeLock: 6, }, { // Insufficient capacity in first channel when fees are added. name: "two hop insufficient", paymentAmount: 100000, hops: []*ChannelHop{ createHop(0, 1000, 100, 10), createHop(0, 1000, 1000, 5), }, expectError: true, expectedErrorCode: ErrInsufficientCapacity, }, { // A three hop payment where the first and second hop // will both charge 1 msat. The fee for the first hop // is actually slightly higher than 1, because the amount // to forward also includes the fee for the second hop. This // gets rounded down to 1. name: "three hop", paymentAmount: 100000, hops: []*ChannelHop{ createHop(0, 10, 1000, 10), createHop(0, 10, 1000, 5), createHop(0, 10, 1000, 3), }, expectedFees: []lnwire.MilliSatoshi{1, 1, 0}, expectedTotalAmount: 100002, expectedTimeLocks: []uint32{4, 1, 1}, expectedTotalTimeLock: 9, }, { // A three hop payment where the fee of the first hop // is slightly higher (11) than the fee at the second hop, // because of the increase amount to forward. name: "three hop with fee carry over", paymentAmount: 100000, hops: []*ChannelHop{ createHop(0, 10000, 1000, 10), createHop(0, 10000, 1000, 5), createHop(0, 10000, 1000, 3), }, expectedFees: []lnwire.MilliSatoshi{1010, 1000, 0}, expectedTotalAmount: 102010, expectedTimeLocks: []uint32{4, 1, 1}, expectedTotalTimeLock: 9, }, { // A three hop payment where the fee policies of the first and // second hop are just high enough to show the fee carry over // effect. name: "three hop with minimal fees for carry over", paymentAmount: 100000, hops: []*ChannelHop{ createHop(0, 10000, 1000, 10), // First hop charges 0.1% so the second hop fee // should show up in the first hop fee as 1 msat // extra. createHop(0, 1000, 1000, 5), // Second hop charges a fixed 1000 msat. createHop(1000, 0, 1000, 3), }, expectedFees: []lnwire.MilliSatoshi{101, 1000, 0}, expectedTotalAmount: 101101, expectedTimeLocks: []uint32{4, 1, 1}, expectedTotalTimeLock: 9, }} for _, testCase := range testCases { assertRoute := func(t *testing.T, route *Route) { if route.TotalAmount != testCase.expectedTotalAmount { t.Errorf("Expected total amount is be %v"+ ", but got %v instead", testCase.expectedTotalAmount, route.TotalAmount) } for i := 0; i < len(testCase.expectedFees); i++ { if testCase.expectedFees[i] != route.Hops[i].Fee { t.Errorf("Expected fee for hop %v to "+ "be %v, but got %v instead", i, testCase.expectedFees[i], route.Hops[i].Fee) } } expectedTimeLockHeight := startingHeight + testCase.expectedTotalTimeLock if route.TotalTimeLock != expectedTimeLockHeight { t.Errorf("Expected total time lock to be %v"+ ", but got %v instead", expectedTimeLockHeight, route.TotalTimeLock) } for i := 0; i < len(testCase.expectedTimeLocks); i++ { expectedTimeLockHeight := startingHeight + testCase.expectedTimeLocks[i] if expectedTimeLockHeight != route.Hops[i].OutgoingTimeLock { t.Errorf("Expected time lock for hop "+ "%v to be %v, but got %v instead", i, expectedTimeLockHeight, route.Hops[i].OutgoingTimeLock) } } } t.Run(testCase.name, func(t *testing.T) { route, err := newRoute(testCase.paymentAmount, noFeeLimit, sourceVertex, testCase.hops, startingHeight, finalHopCLTV) if testCase.expectError { expectedCode := testCase.expectedErrorCode if err == nil || !IsError(err, expectedCode) { t.Errorf("expected newRoute to fail "+ "with error code %v, but got"+ "%v instead", expectedCode, err) } } else { if err != nil { t.Errorf("unable to create path: %v", err) } assertRoute(t, route) } }) } } func TestNewRoutePathTooLong(t *testing.T) { t.Skip() // 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 confirming 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, nil, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt, nil, ) 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, nil, sourceNode, target, ignoredVertexes, ignoredEdges, paymentAmt, nil, ) 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, nil, sourceNode, unknownNode, ignoredVertexes, ignoredEdges, 100, nil, ) 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"] payAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) _, err = findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, payAmt, nil, ) if !IsError(err, ErrNoPathFound) { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } // TestRouteFailMinHTLC tests that if we attempt to route an HTLC which is // smaller than the advertised minHTLC of an edge, then path finding fails. func TestRouteFailMinHTLC(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{}) // We'll not attempt to route an HTLC of 10 SAT from roasbeef to Son // Goku. However, the min HTLC of Son Goku is 1k SAT, as a result, this // attempt should fail. target := aliases["songoku"] payAmt := lnwire.MilliSatoshi(10) _, err = findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, payAmt, nil, ) if !IsError(err, ErrNoPathFound) { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } // TestRouteFailDisabledEdge tests that if we attempt to route to an edge // that's disabled, then that edge is disqualified, and the routing attempt // will fail. func TestRouteFailDisabledEdge(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{}) // First, we'll try to route from roasbeef -> songoku. This should // succeed without issue, and return a single path. target := aliases["songoku"] payAmt := lnwire.NewMSatFromSatoshis(10000) _, err = findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, payAmt, nil, ) if err != nil { t.Fatalf("unable to find path: %v", err) } // First, we'll modify the edge from roasbeef -> songoku, to read that // it's disabled. _, gokuEdge, _, err := graph.FetchChannelEdgesByID(12345) if err != nil { t.Fatalf("unable to fetch goku's edge: %v", err) } gokuEdge.Flags = lnwire.ChanUpdateDisabled if err := graph.UpdateEdgePolicy(gokuEdge); err != nil { t.Fatalf("unable to update edge: %v", err) } // Now, if we attempt to route through that edge, we should get a // failure as it is no longer eligible. _, err = findPath( nil, graph, nil, sourceNode, target, ignoredVertexes, ignoredEdges, payAmt, nil, ) if !IsError(err, ErrNoPathFound) { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } // TestRouteExceededFeeLimit tests that routes respect the fee limit imposed. func TestRouteExceededFeeLimit(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 := Vertex(sourceNode.PubKeyBytes) ignoredVertices := make(map[Vertex]struct{}) ignoredEdges := make(map[uint64]struct{}) // Find a path to send 100 satoshis from roasbeef to sophon. target := aliases["sophon"] amt := lnwire.NewMSatFromSatoshis(100) path, err := findPath( nil, graph, nil, sourceNode, target, ignoredVertices, ignoredEdges, amt, nil, ) if err != nil { t.Fatalf("unable to find path from roasbeef to phamnuwen for "+ "100 satoshis: %v", err) } // We'll now purposefully set a fee limit of 0 to trigger the exceeded // fee limit error. This should work since the path retrieved spans // multiple hops incurring a fee. feeLimit := lnwire.NewMSatFromSatoshis(0) _, err = newRoute(amt, feeLimit, sourceVertex, path, 100, 1) if !IsError(err, ErrFeeLimitExceeded) { t.Fatalf("route should've exceeded fee limit: %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 } func TestPathFindSpecExample(t *testing.T) { t.Parallel() // All our path finding tests will assume a starting height of 100, so // we'll pass that in to ensure that the router uses 100 as the current // height. const startingHeight = 100 ctx, cleanUp, err := createTestCtx(startingHeight, specExampleFilePath) defer cleanUp() if err != nil { t.Fatalf("unable to create router: %v", err) } const ( aliceFinalCLTV = 10 bobFinalCLTV = 20 carolFinalCLTV = 30 daveFinalCLTV = 40 ) // We'll first exercise the scenario of a direct payment from Bob to // Carol, so we set "B" as the source node so path finding starts from // Bob. bob := ctx.aliases["B"] bobNode, err := ctx.graph.FetchLightningNode(bob) if err != nil { t.Fatalf("unable to find bob: %v", err) } if err := ctx.graph.SetSourceNode(bobNode); err != nil { t.Fatalf("unable to set source node: %v", err) } // Query for a route of 4,999,999 mSAT to carol. carol := ctx.aliases["C"] const amt lnwire.MilliSatoshi = 4999999 routes, err := ctx.router.FindRoutes(carol, amt, noFeeLimit, 100) if err != nil { t.Fatalf("unable to find route: %v", err) } // We should come back with _exactly_ two routes. if len(routes) != 2 { t.Fatalf("expected %v routes, instead have: %v", 2, len(routes)) } // Now we'll examine the first route returned for correctness. // // It should be sending the exact payment amount as there are no // additional hops. firstRoute := routes[0] if firstRoute.TotalAmount != amt { t.Fatalf("wrong total amount: got %v, expected %v", firstRoute.TotalAmount, amt) } if firstRoute.Hops[0].AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", firstRoute.Hops[0].AmtToForward, amt) } if firstRoute.Hops[0].Fee != 0 { t.Fatalf("wrong hop fee: got %v, expected %v", firstRoute.Hops[0].Fee, 0) } // The CLTV expiry should be the current height plus 9 (the expiry for // the B -> C channel. if firstRoute.TotalTimeLock != startingHeight+DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", firstRoute.TotalTimeLock, startingHeight+DefaultFinalCLTVDelta) } // Next, we'll set A as the source node so we can assert that we create // the proper route for any queries starting with Alice. alice := ctx.aliases["A"] aliceNode, err := ctx.graph.FetchLightningNode(alice) if err != nil { t.Fatalf("unable to find alice: %v", err) } if err := ctx.graph.SetSourceNode(aliceNode); err != nil { t.Fatalf("unable to set source node: %v", err) } ctx.router.selfNode = aliceNode source, err := ctx.graph.SourceNode() if err != nil { t.Fatalf("unable to retrieve source node: %v", err) } if !bytes.Equal(source.PubKeyBytes[:], alice.SerializeCompressed()) { t.Fatalf("source node not set") } // We'll now request a route from A -> B -> C. ctx.router.routeCache = make(map[routeTuple][]*Route) routes, err = ctx.router.FindRoutes(carol, amt, noFeeLimit, 100) if err != nil { t.Fatalf("unable to find routes: %v", err) } // We should come back with _exactly_ two routes. if len(routes) != 2 { t.Fatalf("expected %v routes, instead have: %v", 2, len(routes)) } // Both routes should be two hops. if len(routes[0].Hops) != 2 { t.Fatalf("route should be %v hops, is instead %v", 2, len(routes[0].Hops)) } if len(routes[1].Hops) != 2 { t.Fatalf("route should be %v hops, is instead %v", 2, len(routes[1].Hops)) } // The total amount should factor in a fee of 10199 and also use a CLTV // delta total of 29 (20 + 9), expectedAmt := lnwire.MilliSatoshi(5010198) if routes[0].TotalAmount != expectedAmt { t.Fatalf("wrong amount: got %v, expected %v", routes[0].TotalAmount, expectedAmt) } if routes[0].TotalTimeLock != startingHeight+29 { t.Fatalf("wrong total time lock: got %v, expecting %v", routes[0].TotalTimeLock, startingHeight+29) } // Ensure that the hops of the first route are properly crafted. // // After taking the fee, Bob should be forwarding the remainder which // is the exact payment to Bob. if routes[0].Hops[0].AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", routes[0].Hops[0].AmtToForward, amt) } // We shouldn't pay any fee for the first, hop, but the fee for the // second hop posted fee should be exactly: // The fee that we pay for the second hop will be "applied to the first // hop, so we should get a fee of exactly: // // * 200 + 4999999 * 2000 / 1000000 = 10199 if routes[0].Hops[0].Fee != 10199 { t.Fatalf("wrong hop fee: got %v, expected %v", routes[0].Hops[0].Fee, 10199) } // While for the final hop, as there's no additional hop afterwards, we // pay no fee. if routes[0].Hops[1].Fee != 0 { t.Fatalf("wrong hop fee: got %v, expected %v", routes[0].Hops[0].Fee, 0) } // The outgoing CLTV value itself should be the current height plus 30 // to meet Carol's requirements. if routes[0].Hops[0].OutgoingTimeLock != startingHeight+DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", routes[0].Hops[0].OutgoingTimeLock, startingHeight+DefaultFinalCLTVDelta) } // For B -> C, we assert that the final hop also has the proper // parameters. lastHop := routes[0].Hops[1] if lastHop.AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", lastHop.AmtToForward, amt) } if lastHop.OutgoingTimeLock != startingHeight+DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", lastHop.OutgoingTimeLock, startingHeight+DefaultFinalCLTVDelta) } // We'll also make similar assertions for the second route from A to C // via D. secondRoute := routes[1] expectedAmt = 5020398 if secondRoute.TotalAmount != expectedAmt { t.Fatalf("wrong amount: got %v, expected %v", secondRoute.TotalAmount, expectedAmt) } expectedTimeLock := startingHeight + daveFinalCLTV + DefaultFinalCLTVDelta if secondRoute.TotalTimeLock != uint32(expectedTimeLock) { t.Fatalf("wrong total time lock: got %v, expecting %v", secondRoute.TotalTimeLock, expectedTimeLock) } onionPayload := secondRoute.Hops[0] if onionPayload.AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", onionPayload.AmtToForward, amt) } expectedTimeLock = startingHeight + DefaultFinalCLTVDelta if onionPayload.OutgoingTimeLock != uint32(expectedTimeLock) { t.Fatalf("wrong outgoing time lock: got %v, expecting %v", onionPayload.OutgoingTimeLock, expectedTimeLock) } // The B -> C hop should also be identical as the prior cases. lastHop = secondRoute.Hops[1] if lastHop.AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", lastHop.AmtToForward, amt) } if lastHop.OutgoingTimeLock != startingHeight+DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", lastHop.OutgoingTimeLock, startingHeight+DefaultFinalCLTVDelta) } } func assertExpectedPath(t *testing.T, path []*ChannelHop, nodeAliases ...string) { if len(path) != len(nodeAliases) { t.Fatal("number of hops and number of aliases do not match") } 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) } } }