package routing import ( "bytes" "crypto/sha256" "encoding/binary" "encoding/hex" "encoding/json" "errors" "fmt" "io/ioutil" "math" "math/big" "net" "os" "reflect" "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/feature" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/record" "github.com/lightningnetwork/lnd/routing/route" "github.com/lightningnetwork/lnd/zpay32" ) 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 ( noRestrictions = &RestrictParams{ FeeLimit: noFeeLimit, ProbabilitySource: noProbabilitySource, CltvLimit: math.MaxUint32, } testPathFindingConfig = &PathFindingConfig{} tlvFeatures = lnwire.NewFeatureVector( lnwire.NewRawFeatureVector( lnwire.TLVOnionPayloadOptional, ), lnwire.Features, ) payAddrFeatures = lnwire.NewFeatureVector( lnwire.NewRawFeatureVector( lnwire.PaymentAddrOptional, ), lnwire.Features, ) tlvPayAddrFeatures = lnwire.NewFeatureVector( lnwire.NewRawFeatureVector( lnwire.TLVOnionPayloadOptional, lnwire.PaymentAddrOptional, ), lnwire.Features, ) ) var ( 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(), } ) // noProbabilitySource is used in testing to return the same probability 1 for // all edges. func noProbabilitySource(route.Vertex, route.Vertex, lnwire.MilliSatoshi) float64 { return 1 } // 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"` ChannelFlags uint8 `json:"channel_flags"` MessageFlags uint8 `json:"message_flags"` Expiry uint16 `json:"expiry"` MinHTLC int64 `json:"min_htlc"` MaxHTLC int64 `json:"max_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 } // parseTestGraph returns a fully populated ChannelGraph given a path to a JSON // file which encodes a test graph. func parseTestGraph(path string) (*testGraphInstance, error) { graphJSON, err := ioutil.ReadFile(path) if err != nil { return 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, 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, 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, err } aliasMap := make(map[string]route.Vertex) 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, err } dbNode := &channeldb.LightningNode{ HaveNodeAnnouncement: true, AuthSigBytes: testSig.Serialize(), LastUpdate: testTime, 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, 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] = dbNode.PubKeyBytes // 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, 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, err } } if source != nil { // Set the selected source node if err := graph.SetSourceNode(source); err != nil { return 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, err } node2Bytes, err := hex.DecodeString(edge.Node2) if err != nil { return nil, err } if bytes.Compare(node1Bytes, node2Bytes) == 1 { return nil, fmt.Errorf( "channel %v node order incorrect", edge.ChannelID, ) } fundingTXID := strings.Split(edge.ChannelPoint, ":")[0] txidBytes, err := chainhash.NewHashFromStr(fundingTXID) if err != nil { return 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, err } edgePolicy := &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), MessageFlags: lnwire.ChanUpdateMsgFlags(edge.MessageFlags), ChannelFlags: lnwire.ChanUpdateChanFlags(edge.ChannelFlags), ChannelID: edge.ChannelID, LastUpdate: testTime, TimeLockDelta: edge.Expiry, MinHTLC: lnwire.MilliSatoshi(edge.MinHTLC), MaxHTLC: lnwire.MilliSatoshi(edge.MaxHTLC), FeeBaseMSat: lnwire.MilliSatoshi(edge.FeeBaseMsat), FeeProportionalMillionths: lnwire.MilliSatoshi(edge.FeeRate), } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, err } } return &testGraphInstance{ graph: graph, cleanUp: cleanUp, aliasMap: aliasMap, }, nil } type testChannelPolicy struct { Expiry uint16 MinHTLC lnwire.MilliSatoshi MaxHTLC lnwire.MilliSatoshi FeeBaseMsat lnwire.MilliSatoshi FeeRate lnwire.MilliSatoshi LastUpdate time.Time Disabled bool Features *lnwire.FeatureVector } type testChannelEnd struct { Alias string *testChannelPolicy } func symmetricTestChannel(alias1, alias2 string, capacity btcutil.Amount, policy *testChannelPolicy, chanID ...uint64) *testChannel { // Leaving id zero will result in auto-generation of a channel id during // graph construction. var id uint64 if len(chanID) > 0 { id = chanID[0] } policy2 := *policy return asymmetricTestChannel( alias1, alias2, capacity, policy, &policy2, id, ) } func asymmetricTestChannel(alias1, alias2 string, capacity btcutil.Amount, policy1, policy2 *testChannelPolicy, id uint64) *testChannel { return &testChannel{ Capacity: capacity, Node1: &testChannelEnd{ Alias: alias1, testChannelPolicy: policy1, }, Node2: &testChannelEnd{ Alias: alias2, testChannelPolicy: policy2, }, ChannelID: id, } } type testChannel struct { Node1 *testChannelEnd Node2 *testChannelEnd Capacity btcutil.Amount ChannelID uint64 } type testGraphInstance struct { graph *channeldb.ChannelGraph cleanUp func() // 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. aliasMap map[string]route.Vertex // privKeyMap maps a node alias to its private key. This is used to be // able to mock a remote node's signing behaviour. privKeyMap map[string]*btcec.PrivateKey } // createTestGraphFromChannels 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 createTestGraphFromChannels(testChannels []*testChannel, source string) ( *testGraphInstance, 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, 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, err } aliasMap := make(map[string]route.Vertex) privKeyMap := make(map[string]*btcec.PrivateKey) nodeIndex := byte(0) addNodeWithAlias := func(alias string, features *lnwire.FeatureVector) ( *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, } privKey, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), keyBytes) if features == nil { features = lnwire.EmptyFeatureVector() } dbNode := &channeldb.LightningNode{ HaveNodeAnnouncement: true, AuthSigBytes: testSig.Serialize(), LastUpdate: testTime, Addresses: testAddrs, Alias: alias, Features: features, } copy(dbNode.PubKeyBytes[:], pubKey.SerializeCompressed()) privKeyMap[alias] = privKey // 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] = dbNode.PubKeyBytes nodeIndex++ return dbNode, nil } // Add the source node. dbNode, err := addNodeWithAlias(source, lnwire.EmptyFeatureVector()) if err != nil { return nil, err } if err = graph.SetSourceNode(dbNode); err != nil { return nil, err } // Initialize variable that keeps track of the next channel id to assign // if none is specified. nextUnassignedChannelID := uint64(100000) for _, testChannel := range testChannels { for _, node := range []*testChannelEnd{ testChannel.Node1, testChannel.Node2} { _, exists := aliasMap[node.Alias] if !exists { var features *lnwire.FeatureVector if node.testChannelPolicy != nil { features = node.testChannelPolicy.Features } _, err := addNodeWithAlias( node.Alias, features, ) if err != nil { return nil, err } } } channelID := testChannel.ChannelID // If no channel id is specified, generate an id. if channelID == 0 { channelID = nextUnassignedChannelID nextUnassignedChannelID++ } var hash [sha256.Size]byte hash[len(hash)-1] = byte(channelID) fundingPoint := &wire.OutPoint{ Hash: chainhash.Hash(hash), Index: 0, } // Sort nodes node1 := testChannel.Node1 node2 := testChannel.Node2 node1Vertex := aliasMap[node1.Alias] node2Vertex := aliasMap[node2.Alias] if bytes.Compare(node1Vertex[:], node2Vertex[:]) == 1 { node1, node2 = node2, node1 node1Vertex, node2Vertex = node2Vertex, node1Vertex } // We first insert the existence of the edge between the two // nodes. edgeInfo := channeldb.ChannelEdgeInfo{ ChannelID: channelID, AuthProof: &testAuthProof, ChannelPoint: *fundingPoint, Capacity: testChannel.Capacity, NodeKey1Bytes: node1Vertex, BitcoinKey1Bytes: node1Vertex, NodeKey2Bytes: node2Vertex, BitcoinKey2Bytes: node2Vertex, } err = graph.AddChannelEdge(&edgeInfo) if err != nil && err != channeldb.ErrEdgeAlreadyExist { return nil, err } if node1.testChannelPolicy != nil { var msgFlags lnwire.ChanUpdateMsgFlags if node1.MaxHTLC != 0 { msgFlags |= lnwire.ChanUpdateOptionMaxHtlc } var channelFlags lnwire.ChanUpdateChanFlags if node1.Disabled { channelFlags |= lnwire.ChanUpdateDisabled } edgePolicy := &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), MessageFlags: msgFlags, ChannelFlags: channelFlags, ChannelID: channelID, LastUpdate: node1.LastUpdate, TimeLockDelta: node1.Expiry, MinHTLC: node1.MinHTLC, MaxHTLC: node1.MaxHTLC, FeeBaseMSat: node1.FeeBaseMsat, FeeProportionalMillionths: node1.FeeRate, } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, err } } if node2.testChannelPolicy != nil { var msgFlags lnwire.ChanUpdateMsgFlags if node2.MaxHTLC != 0 { msgFlags |= lnwire.ChanUpdateOptionMaxHtlc } var channelFlags lnwire.ChanUpdateChanFlags if node2.Disabled { channelFlags |= lnwire.ChanUpdateDisabled } channelFlags |= lnwire.ChanUpdateDirection edgePolicy := &channeldb.ChannelEdgePolicy{ SigBytes: testSig.Serialize(), MessageFlags: msgFlags, ChannelFlags: channelFlags, ChannelID: channelID, LastUpdate: node2.LastUpdate, TimeLockDelta: node2.Expiry, MinHTLC: node2.MinHTLC, MaxHTLC: node2.MaxHTLC, FeeBaseMSat: node2.FeeBaseMsat, FeeProportionalMillionths: node2.FeeRate, } if err := graph.UpdateEdgePolicy(edgePolicy); err != nil { return nil, err } } channelID++ } return &testGraphInstance{ graph: graph, cleanUp: cleanUp, aliasMap: aliasMap, privKeyMap: privKeyMap, }, 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", "first", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }), symmetricTestChannel("first", "a", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }), symmetricTestChannel("first", "b", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 100, MinHTLC: 1, MaxHTLC: 100000000, }), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 600, MinHTLC: 1, MaxHTLC: 100000000, }), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() const ( startingHeight = 100 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( ctx.source, path, startingHeight, finalHopParams{ amt: paymentAmt, cltvDelta: finalHopCLTV, records: nil, }, ) if err != nil { t.Fatalf("unable to create path: %v", err) } // Assert that the lowest fee route is returned. if route.Hops[1].PubKeyBytes != ctx.keyFromAlias("b") { t.Fatalf("expected route to pass through b, "+ "but got a route through %v", ctx.aliasFromKey(route.Hops[1].PubKeyBytes)) } } func getAliasFromPubKey(pubKey route.Vertex, aliases map[string]route.Vertex) string { for alias, key := range aliases { if key == pubKey { return alias } } return "" } type expectedHop struct { alias string fee lnwire.MilliSatoshi fwdAmount lnwire.MilliSatoshi timeLock uint32 } type basicGraphPathFindingTestCase struct { target string paymentAmt btcutil.Amount feeLimit lnwire.MilliSatoshi expectedTotalAmt lnwire.MilliSatoshi expectedTotalTimeLock uint32 expectedHops []expectedHop expectFailureNoPath bool } var basicGraphPathFindingTests = []basicGraphPathFindingTestCase{ // Basic route with one intermediate hop. {target: "sophon", paymentAmt: 100, feeLimit: noFeeLimit, expectedTotalTimeLock: 102, expectedTotalAmt: 100110, expectedHops: []expectedHop{ {alias: "songoku", fwdAmount: 100000, fee: 110, timeLock: 101}, {alias: "sophon", fwdAmount: 100000, fee: 0, timeLock: 101}, }}, // Basic direct (one hop) route. {target: "luoji", paymentAmt: 100, feeLimit: noFeeLimit, expectedTotalTimeLock: 101, expectedTotalAmt: 100000, expectedHops: []expectedHop{ {alias: "luoji", fwdAmount: 100000, fee: 0, timeLock: 101}, }}, // Three hop route where fees need to be added in to the forwarding amount. // The high fee hop phamnewun should be avoided. {target: "elst", paymentAmt: 50000, feeLimit: noFeeLimit, expectedTotalTimeLock: 103, expectedTotalAmt: 50050210, expectedHops: []expectedHop{ {alias: "songoku", fwdAmount: 50000200, fee: 50010, timeLock: 102}, {alias: "sophon", fwdAmount: 50000000, fee: 200, timeLock: 101}, {alias: "elst", fwdAmount: 50000000, fee: 0, timeLock: 101}, }}, // Three hop route where fees need to be added in to the forwarding amount. // However this time the fwdAmount becomes too large for the roasbeef <-> // songoku channel. Then there is no other option than to choose the // expensive phamnuwen channel. This test case was failing before // the route search was executed backwards. {target: "elst", paymentAmt: 100000, feeLimit: noFeeLimit, expectedTotalTimeLock: 103, expectedTotalAmt: 110010220, expectedHops: []expectedHop{ {alias: "phamnuwen", fwdAmount: 100000200, fee: 10010020, timeLock: 102}, {alias: "sophon", fwdAmount: 100000000, fee: 200, timeLock: 101}, {alias: "elst", fwdAmount: 100000000, fee: 0, timeLock: 101}, }}, // Basic route with fee limit. {target: "sophon", paymentAmt: 100, feeLimit: 50, expectFailureNoPath: true, }} func TestBasicGraphPathFinding(t *testing.T) { t.Parallel() testGraphInstance, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer testGraphInstance.cleanUp() // 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. for _, testCase := range basicGraphPathFindingTests { t.Run(testCase.target, func(subT *testing.T) { testBasicGraphPathFindingCase(subT, testGraphInstance, &testCase) }) } } func testBasicGraphPathFindingCase(t *testing.T, graphInstance *testGraphInstance, test *basicGraphPathFindingTestCase) { aliases := graphInstance.aliasMap expectedHops := test.expectedHops expectedHopCount := len(expectedHops) sourceNode, err := graphInstance.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } sourceVertex := route.Vertex(sourceNode.PubKeyBytes) const ( startingHeight = 100 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(test.paymentAmt) target := graphInstance.aliasMap[test.target] path, err := findPath( &graphParams{ graph: graphInstance.graph, }, &RestrictParams{ FeeLimit: test.feeLimit, ProbabilitySource: noProbabilitySource, CltvLimit: math.MaxUint32, }, testPathFindingConfig, sourceNode.PubKeyBytes, target, paymentAmt, startingHeight+finalHopCLTV, ) if test.expectFailureNoPath { if err == nil { t.Fatal("expected no path to be found") } return } if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( sourceVertex, path, startingHeight, finalHopParams{ amt: paymentAmt, cltvDelta: finalHopCLTV, records: nil, }, ) if err != nil { t.Fatalf("unable to create path: %v", err) } if len(route.Hops) != len(expectedHops) { t.Fatalf("route is of incorrect length, expected %v got %v", expectedHopCount, len(route.Hops)) } // Check hop nodes for i := 0; i < len(expectedHops); i++ { if route.Hops[i].PubKeyBytes != aliases[expectedHops[i].alias] { t.Fatalf("%v-th hop should be %v, is instead: %v", i, expectedHops[i], getAliasFromPubKey(route.Hops[i].PubKeyBytes, aliases)) } } // 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. sphinxPath, err := route.ToSphinxPath() if err != nil { t.Fatalf("unable to make sphinx path: %v", err) } if sphinxPath.TrueRouteLength() != expectedHopCount { t.Fatalf("incorrect number of hop payloads: expected %v, got %v", expectedHopCount, sphinxPath.TrueRouteLength()) } // Hops should point to the next hop for i := 0; i < len(expectedHops)-1; i++ { var expectedHop [8]byte binary.BigEndian.PutUint64(expectedHop[:], route.Hops[i+1].ChannelID) hopData, err := sphinxPath[i].HopPayload.HopData() if err != nil { t.Fatalf("unable to make hop data: %v", err) } if !bytes.Equal(hopData.NextAddress[:], expectedHop[:]) { t.Fatalf("first hop has incorrect next hop: expected %x, got %x", expectedHop[:], hopData.NextAddress[:]) } } // The final hop should have a next hop value of all zeroes in order // to indicate it's the exit hop. var exitHop [8]byte lastHopIndex := len(expectedHops) - 1 hopData, err := sphinxPath[lastHopIndex].HopPayload.HopData() if err != nil { t.Fatalf("unable to create hop data: %v", err) } if !bytes.Equal(hopData.NextAddress[:], exitHop[:]) { t.Fatalf("first hop has incorrect next hop: expected %x, got %x", exitHop[:], hopData.NextAddress) } var expectedTotalFee lnwire.MilliSatoshi for i := 0; i < expectedHopCount; i++ { // We'll ensure that the amount to forward, and fees // computed for each hop are correct. fee := route.HopFee(i) if fee != expectedHops[i].fee { t.Fatalf("fee incorrect for hop %v: expected %v, got %v", i, expectedHops[i].fee, fee) } if route.Hops[i].AmtToForward != expectedHops[i].fwdAmount { t.Fatalf("forwarding amount for hop %v incorrect: "+ "expected %v, got %v", i, expectedHops[i].fwdAmount, route.Hops[i].AmtToForward) } // We'll also assert that the outgoing CLTV value for each // hop was set accordingly. if route.Hops[i].OutgoingTimeLock != expectedHops[i].timeLock { t.Fatalf("outgoing time-lock for hop %v is incorrect: "+ "expected %v, got %v", i, expectedHops[i].timeLock, route.Hops[i].OutgoingTimeLock) } expectedTotalFee += expectedHops[i].fee } if route.TotalAmount != test.expectedTotalAmt { t.Fatalf("total amount incorrect: "+ "expected %v, got %v", test.expectedTotalAmt, route.TotalAmount) } if route.TotalTimeLock != test.expectedTotalTimeLock { t.Fatalf("expected time lock of %v, instead have %v", 2, route.TotalTimeLock) } } // TestPathFindingWithAdditionalEdges asserts that we are able to find paths to // nodes that do not exist in the graph by way of hop hints. We also test that // the path can support custom TLV records for the receiver under the // appropriate circumstances. func TestPathFindingWithAdditionalEdges(t *testing.T) { t.Parallel() graph, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.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" copy(doge.PubKeyBytes[:], dogePubKeyBytes) graph.aliasMap["doge"] = doge.PubKeyBytes // 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[route.Vertex][]*channeldb.ChannelEdgePolicy{ graph.aliasMap["songoku"]: {songokuToDoge}, } find := func(r *RestrictParams) ( []*channeldb.ChannelEdgePolicy, error) { return findPath( &graphParams{ graph: graph.graph, additionalEdges: additionalEdges, }, r, testPathFindingConfig, sourceNode.PubKeyBytes, doge.PubKeyBytes, paymentAmt, 0, ) } // We should now be able to find a path from roasbeef to doge. path, err := find(noRestrictions) 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, graph.aliasMap, path, "songoku", "doge") // Now, set custom records for the final hop. This should fail since no // dest features are set, and we won't have a node ann to fall back on. restrictions := *noRestrictions restrictions.DestCustomRecords = record.CustomSet{70000: []byte{}} _, err = find(&restrictions) if err != errNoTlvPayload { t.Fatalf("path shouldn't have been found: %v", err) } // Set empty dest features so we don't try the fallback. We should still // fail since the tlv feature isn't set. restrictions.DestFeatures = lnwire.EmptyFeatureVector() _, err = find(&restrictions) if err != errNoTlvPayload { t.Fatalf("path shouldn't have been found: %v", err) } // Finally, set the tlv feature in the payload and assert we found the // same path as before. restrictions.DestFeatures = tlvFeatures path, err = find(&restrictions) if err != nil { t.Fatalf("path should have been found: %v", err) } assertExpectedPath(t, graph.aliasMap, path, "songoku", "doge") } // TestNewRoute tests whether the construction of hop payloads by newRoute // is executed correctly. func TestNewRoute(t *testing.T) { var sourceKey [33]byte sourceVertex := route.Vertex(sourceKey) testPaymentAddr := [32]byte{0x01, 0x02, 0x03} const ( startingHeight = 100 finalHopCLTV = 1 ) createHop := func(baseFee lnwire.MilliSatoshi, feeRate lnwire.MilliSatoshi, bandwidth lnwire.MilliSatoshi, timeLockDelta uint16) *channeldb.ChannelEdgePolicy { return &channeldb.ChannelEdgePolicy{ Node: &channeldb.LightningNode{ Features: lnwire.NewFeatureVector( nil, nil, ), }, FeeProportionalMillionths: feeRate, FeeBaseMSat: baseFee, TimeLockDelta: timeLockDelta, } } 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 []*channeldb.ChannelEdgePolicy // paymentAmount is the amount that is send into the route // indicated by hops. paymentAmount lnwire.MilliSatoshi // destFeatures is a feature vector, that if non-nil, will // overwrite the final hop's feature vector in the graph. destFeatures *lnwire.FeatureVector paymentAddr *[32]byte // 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 expectedTLVPayload bool expectedMPP *record.MPP }{ { // For a single hop payment, no fees are expected to be paid. name: "single hop", paymentAmount: 100000, hops: []*channeldb.ChannelEdgePolicy{ createHop(100, 1000, 1000000, 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: []*channeldb.ChannelEdgePolicy{ createHop(0, 1000, 1000000, 10), createHop(30, 1000, 1000000, 5), }, expectedFees: []lnwire.MilliSatoshi{130, 0}, expectedTimeLocks: []uint32{1, 1}, expectedTotalAmount: 100130, expectedTotalTimeLock: 6, }, { // 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 tlv onion feature", destFeatures: tlvFeatures, paymentAmount: 100000, hops: []*channeldb.ChannelEdgePolicy{ createHop(0, 1000, 1000000, 10), createHop(30, 1000, 1000000, 5), }, expectedFees: []lnwire.MilliSatoshi{130, 0}, expectedTimeLocks: []uint32{1, 1}, expectedTotalAmount: 100130, expectedTotalTimeLock: 6, expectedTLVPayload: true, }, { // 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 single shot mpp", destFeatures: tlvPayAddrFeatures, paymentAddr: &testPaymentAddr, paymentAmount: 100000, hops: []*channeldb.ChannelEdgePolicy{ createHop(0, 1000, 1000000, 10), createHop(30, 1000, 1000000, 5), }, expectedFees: []lnwire.MilliSatoshi{130, 0}, expectedTimeLocks: []uint32{1, 1}, expectedTotalAmount: 100130, expectedTotalTimeLock: 6, expectedTLVPayload: true, expectedMPP: record.NewMPP( 100000, testPaymentAddr, ), }, { // 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: []*channeldb.ChannelEdgePolicy{ createHop(0, 10, 1000000, 10), createHop(0, 10, 1000000, 5), createHop(0, 10, 1000000, 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: []*channeldb.ChannelEdgePolicy{ createHop(0, 10000, 1000000, 10), createHop(0, 10000, 1000000, 5), createHop(0, 10000, 1000000, 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: []*channeldb.ChannelEdgePolicy{ createHop(0, 10000, 1000000, 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, 1000000, 5), // Second hop charges a fixed 1000 msat. createHop(1000, 0, 1000000, 3), }, expectedFees: []lnwire.MilliSatoshi{101, 1000, 0}, expectedTotalAmount: 101101, expectedTimeLocks: []uint32{4, 1, 1}, expectedTotalTimeLock: 9, }} for _, testCase := range testCases { testCase := testCase // Overwrite the final hop's features if the test requires a // custom feature vector. if testCase.destFeatures != nil { finalHop := testCase.hops[len(testCase.hops)-1] finalHop.Node.Features = testCase.destFeatures } assertRoute := func(t *testing.T, route *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++ { fee := route.HopFee(i) if testCase.expectedFees[i] != fee { t.Errorf("Expected fee for hop %v to "+ "be %v, but got %v instead", i, testCase.expectedFees[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) } } finalHop := route.Hops[len(route.Hops)-1] if !finalHop.LegacyPayload != testCase.expectedTLVPayload { t.Errorf("Expected final hop tlv payload: %t, "+ "but got: %t instead", testCase.expectedTLVPayload, !finalHop.LegacyPayload) } if !reflect.DeepEqual( finalHop.MPP, testCase.expectedMPP, ) { t.Errorf("Expected final hop mpp field: %v, "+ " but got: %v instead", testCase.expectedMPP, finalHop.MPP) } } t.Run(testCase.name, func(t *testing.T) { route, err := newRoute( sourceVertex, testCase.hops, startingHeight, finalHopParams{ amt: testCase.paymentAmount, cltvDelta: finalHopCLTV, records: nil, paymentAddr: testCase.paymentAddr, }, ) if testCase.expectError { expectedCode := testCase.expectedErrorCode if err == nil || !IsError(err, expectedCode) { t.Fatalf("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) return } assertRoute(t, route) } }) } } func TestNewRoutePathTooLong(t *testing.T) { t.Parallel() var testChannels []*testChannel // Setup a linear network of 21 hops. fromNode := "start" for i := 0; i < 21; i++ { toNode := fmt.Sprintf("node-%v", i+1) c := symmetricTestChannel(fromNode, toNode, 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000001, }) testChannels = append(testChannels, c) fromNode = toNode } ctx := newPathFindingTestContext(t, testChannels, "start") defer ctx.cleanup() // Assert that we can find 20 hop routes. node20 := ctx.keyFromAlias("node-20") payAmt := lnwire.MilliSatoshi(100001) _, err := ctx.findPath(node20, payAmt) if err != nil { t.Fatalf("unexpected pathfinding failure: %v", err) } // Assert that finding a 21 hop route fails. node21 := ctx.keyFromAlias("node-21") _, err = ctx.findPath(node21, payAmt) if err != errNoPathFound { t.Fatalf("not route error expected, but got %v", err) } // Assert that we can't find a 20 hop route if custom records make it // exceed the maximum payload size. ctx.restrictParams.DestFeatures = tlvFeatures ctx.restrictParams.DestCustomRecords = map[uint64][]byte{ 100000: bytes.Repeat([]byte{1}, 100), } _, err = ctx.findPath(node20, payAmt) if err != errNoPathFound { t.Fatalf("not route error expected, but got %v", err) } } func TestPathNotAvailable(t *testing.T) { t.Parallel() graph, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // 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) } var unknownNode route.Vertex copy(unknownNode[:], unknownNodeBytes) _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, unknownNode, 100, 0, ) if err != errNoPathFound { t.Fatalf("path shouldn't have been found: %v", err) } } // TestDestTLVGraphFallback asserts that we properly detect when we can send TLV // records to a receiver, and also that we fallback to the receiver's node // announcement if we don't have an invoice features. func TestDestTLVGraphFallback(t *testing.T) { t.Parallel() testChannels := []*testChannel{ asymmetricTestChannel("roasbeef", "luoji", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, 0), asymmetricTestChannel("roasbeef", "satoshi", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, Features: tlvFeatures, }, 0), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() sourceNode, err := ctx.graphParams.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } find := func(r *RestrictParams, target route.Vertex) ([]*channeldb.ChannelEdgePolicy, error) { return findPath( &graphParams{ graph: ctx.graphParams.graph, }, r, testPathFindingConfig, sourceNode.PubKeyBytes, target, 100, 0, ) } // Luoji's node ann has an empty feature vector. luoji := ctx.testGraphInstance.aliasMap["luoji"] // Satoshi's node ann supports TLV. satoshi := ctx.testGraphInstance.aliasMap["satoshi"] restrictions := *noRestrictions // Add custom records w/o any dest features. restrictions.DestCustomRecords = record.CustomSet{70000: []byte{}} // Path to luoji should fail because his node ann features are empty. _, err = find(&restrictions, luoji) if err != errNoTlvPayload { t.Fatalf("path shouldn't have been found: %v", err) } // However, path to satoshi should succeed via the fallback because his // node ann features have the TLV bit. path, err := find(&restrictions, satoshi) if err != nil { t.Fatalf("path should have been found: %v", err) } assertExpectedPath(t, ctx.testGraphInstance.aliasMap, path, "satoshi") // Add empty destination features. This should cause both paths to fail, // since this override anything in the graph. restrictions.DestFeatures = lnwire.EmptyFeatureVector() _, err = find(&restrictions, luoji) if err != errNoTlvPayload { t.Fatalf("path shouldn't have been found: %v", err) } _, err = find(&restrictions, satoshi) if err != errNoTlvPayload { t.Fatalf("path shouldn't have been found: %v", err) } // Finally, set the TLV dest feature. We should succeed in finding a // path to luoji. restrictions.DestFeatures = tlvFeatures path, err = find(&restrictions, luoji) if err != nil { t.Fatalf("path should have been found: %v", err) } assertExpectedPath(t, ctx.testGraphInstance.aliasMap, path, "luoji") } // TestMissingFeatureDep asserts that we fail path finding when the // destination's features are broken, in that the feature vector doesn't signal // all transitive dependencies. func TestMissingFeatureDep(t *testing.T) { t.Parallel() testChannels := []*testChannel{ asymmetricTestChannel("roasbeef", "conner", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, Features: payAddrFeatures, }, 0, ), asymmetricTestChannel("conner", "joost", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, Features: payAddrFeatures, }, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, 0, ), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() sourceNode, err := ctx.graphParams.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } find := func(r *RestrictParams, target route.Vertex) ([]*channeldb.ChannelEdgePolicy, error) { return findPath( &graphParams{ graph: ctx.graphParams.graph, }, r, testPathFindingConfig, sourceNode.PubKeyBytes, target, 100, 0, ) } // Conner's node in the graph has a broken feature vector, since it // signals payment addresses without signaling tlv onions. Pathfinding // should fail since we validate transitive feature dependencies for the // final node. conner := ctx.testGraphInstance.aliasMap["conner"] restrictions := *noRestrictions _, err = find(&restrictions, conner) if err != feature.NewErrMissingFeatureDep( lnwire.TLVOnionPayloadOptional, ) { t.Fatalf("path shouldn't have been found: %v", err) } // Now, set the TLV and payment addresses features to override the // broken features found in the graph. We should succeed in finding a // path to conner. restrictions.DestFeatures = tlvPayAddrFeatures path, err := find(&restrictions, conner) if err != nil { t.Fatalf("path should have been found: %v", err) } assertExpectedPath(t, ctx.testGraphInstance.aliasMap, path, "conner") // Finally, try to find a route to joost through conner. The // destination features are set properly from the previous assertions, // but conner's feature vector in the graph is still broken. We expect // errNoPathFound and not the missing feature dep err above since // intermediate hops are simply skipped if they have invalid feature // vectors, leaving no possible route to joost. joost := ctx.testGraphInstance.aliasMap["joost"] _, err = find(&restrictions, joost) if err != errNoPathFound { t.Fatalf("path shouldn't have been found: %v", err) } } // TestDestPaymentAddr asserts that we properly detect when we can send a // payment address to a receiver, and also that we fallback to the receiver's // node announcement if we don't have an invoice features. func TestDestPaymentAddr(t *testing.T) { t.Parallel() testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "luoji", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000000, }, ), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() sourceNode, err := ctx.graphParams.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } find := func(r *RestrictParams, target route.Vertex) ([]*channeldb.ChannelEdgePolicy, error) { return findPath( &graphParams{ graph: ctx.graphParams.graph, }, r, testPathFindingConfig, sourceNode.PubKeyBytes, target, 100, 0, ) } luoji := ctx.testGraphInstance.aliasMap["luoji"] restrictions := *noRestrictions // Add payment address w/o any invoice features. restrictions.PaymentAddr = &[32]byte{1} // Add empty destination features. This should cause us to fail, since // this overrides anything in the graph. restrictions.DestFeatures = lnwire.EmptyFeatureVector() _, err = find(&restrictions, luoji) if err != errNoPaymentAddr { t.Fatalf("path shouldn't have been found: %v", err) } // Now, set the TLV and payment address features for the destination. We // should succeed in finding a path to luoji. restrictions.DestFeatures = tlvPayAddrFeatures path, err := find(&restrictions, luoji) if err != nil { t.Fatalf("path should have been found: %v", err) } assertExpectedPath(t, ctx.testGraphInstance.aliasMap, path, "luoji") } func TestPathInsufficientCapacity(t *testing.T) { t.Parallel() graph, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // 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 := graph.aliasMap["sophon"] payAmt := lnwire.NewMSatFromSatoshis(btcutil.SatoshiPerBitcoin) _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if 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, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // 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 := graph.aliasMap["songoku"] payAmt := lnwire.MilliSatoshi(10) _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != errNoPathFound { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } // TestRouteFailMaxHTLC tests that if we attempt to route an HTLC which is // larger than the advertised max HTLC of an edge, then path finding fails. func TestRouteFailMaxHTLC(t *testing.T) { t.Parallel() // Set up a test graph: // roasbeef <--> firstHop <--> secondHop <--> target // We will be adjusting the max HTLC of the edge between the first and // second hops. var firstToSecondID uint64 = 1 testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "first", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000001, }), symmetricTestChannel("first", "second", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000002, }, firstToSecondID), symmetricTestChannel("second", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, MinHTLC: 1, MaxHTLC: 100000003, }), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() // First, attempt to send a payment greater than the max HTLC we are // about to set, which should succeed. target := ctx.keyFromAlias("target") payAmt := lnwire.MilliSatoshi(100001) _, err := ctx.findPath(target, payAmt) if err != nil { t.Fatalf("graph should've been able to support payment: %v", err) } // Next, update the middle edge policy to only allow payments up to 100k // msat. graph := ctx.testGraphInstance.graph _, midEdge, _, err := graph.FetchChannelEdgesByID(firstToSecondID) if err != nil { t.Fatalf("unable to fetch channel edges by ID: %v", err) } midEdge.MessageFlags = 1 midEdge.MaxHTLC = payAmt - 1 if err := graph.UpdateEdgePolicy(midEdge); err != nil { t.Fatalf("unable to update edge: %v", err) } // We'll now attempt to route through that edge with a payment above // 100k msat, which should fail. _, err = ctx.findPath(target, payAmt) if 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. We also test that this is true only for non-local edges, as we'll // ignore the disable flags, with the assumption that the correct bandwidth is // found among the bandwidth hints. func TestRouteFailDisabledEdge(t *testing.T) { t.Parallel() graph, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // First, we'll try to route from roasbeef -> sophon. This should // succeed without issue, and return a single path via phamnuwen target := graph.aliasMap["sophon"] payAmt := lnwire.NewMSatFromSatoshis(105000) _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != nil { t.Fatalf("unable to find path: %v", err) } // Disable the edge roasbeef->phamnuwen. This should not impact the // path finding, as we don't consider the disable flag for local // channels (and roasbeef is the source). roasToPham := uint64(999991) _, e1, e2, err := graph.graph.FetchChannelEdgesByID(roasToPham) if err != nil { t.Fatalf("unable to fetch edge: %v", err) } e1.ChannelFlags |= lnwire.ChanUpdateDisabled if err := graph.graph.UpdateEdgePolicy(e1); err != nil { t.Fatalf("unable to update edge: %v", err) } e2.ChannelFlags |= lnwire.ChanUpdateDisabled if err := graph.graph.UpdateEdgePolicy(e2); err != nil { t.Fatalf("unable to update edge: %v", err) } _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != nil { t.Fatalf("unable to find path: %v", err) } // Now, we'll modify the edge from phamnuwen -> sophon, to read that // it's disabled. phamToSophon := uint64(99999) _, e, _, err := graph.graph.FetchChannelEdgesByID(phamToSophon) if err != nil { t.Fatalf("unable to fetch edge: %v", err) } e.ChannelFlags |= lnwire.ChanUpdateDisabled if err := graph.graph.UpdateEdgePolicy(e); err != nil { t.Fatalf("unable to update edge: %v", err) } // If we attempt to route through that edge, we should get a failure as // it is no longer eligible. _, err = findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != errNoPathFound { t.Fatalf("graph shouldn't be able to support payment: %v", err) } } // TestPathSourceEdgesBandwidth tests that explicitly passing in a set of // bandwidth hints is used by the path finding algorithm to consider whether to // use a local channel. func TestPathSourceEdgesBandwidth(t *testing.T) { t.Parallel() graph, err := parseTestGraph(basicGraphFilePath) if err != nil { t.Fatalf("unable to create graph: %v", err) } defer graph.cleanUp() sourceNode, err := graph.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } // First, we'll try to route from roasbeef -> sophon. This should // succeed without issue, and return a path via songoku, as that's the // cheapest path. target := graph.aliasMap["sophon"] payAmt := lnwire.NewMSatFromSatoshis(50000) path, err := findPath( &graphParams{ graph: graph.graph, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != nil { t.Fatalf("unable to find path: %v", err) } assertExpectedPath(t, graph.aliasMap, path, "songoku", "sophon") // Now we'll set the bandwidth of the edge roasbeef->songoku and // roasbeef->phamnuwen to 0. roasToSongoku := uint64(12345) roasToPham := uint64(999991) bandwidths := map[uint64]lnwire.MilliSatoshi{ roasToSongoku: 0, roasToPham: 0, } // Since both these edges has a bandwidth of zero, no path should be // found. _, err = findPath( &graphParams{ graph: graph.graph, bandwidthHints: bandwidths, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != errNoPathFound { t.Fatalf("graph shouldn't be able to support payment: %v", err) } // Set the bandwidth of roasbeef->phamnuwen high enough to carry the // payment. bandwidths[roasToPham] = 2 * payAmt // Now, if we attempt to route again, we should find the path via // phamnuven, as the other source edge won't be considered. path, err = findPath( &graphParams{ graph: graph.graph, bandwidthHints: bandwidths, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != nil { t.Fatalf("unable to find path: %v", err) } assertExpectedPath(t, graph.aliasMap, path, "phamnuwen", "sophon") // Finally, set the roasbeef->songoku bandwidth, but also set its // disable flag. bandwidths[roasToSongoku] = 2 * payAmt _, e1, e2, err := graph.graph.FetchChannelEdgesByID(roasToSongoku) if err != nil { t.Fatalf("unable to fetch edge: %v", err) } e1.ChannelFlags |= lnwire.ChanUpdateDisabled if err := graph.graph.UpdateEdgePolicy(e1); err != nil { t.Fatalf("unable to update edge: %v", err) } e2.ChannelFlags |= lnwire.ChanUpdateDisabled if err := graph.graph.UpdateEdgePolicy(e2); err != nil { t.Fatalf("unable to update edge: %v", err) } // Since we ignore disable flags for local channels, a path should // still be found. path, err = findPath( &graphParams{ graph: graph.graph, bandwidthHints: bandwidths, }, noRestrictions, testPathFindingConfig, sourceNode.PubKeyBytes, target, payAmt, 0, ) if err != nil { t.Fatalf("unable to find path: %v", err) } assertExpectedPath(t, graph.aliasMap, path, "songoku", "sophon") } 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 := createTestCtxFromFile(startingHeight, specExampleFilePath) if err != nil { t.Fatalf("unable to create router: %v", err) } defer cleanUp() // 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(nil, 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 route, err := ctx.router.FindRoute( bobNode.PubKeyBytes, carol, amt, noRestrictions, nil, ) if err != nil { t.Fatalf("unable to find route: %v", err) } // Now we'll examine the route returned for correctness. // // It should be sending the exact payment amount as there are no // additional hops. if route.TotalAmount != amt { t.Fatalf("wrong total amount: got %v, expected %v", route.TotalAmount, amt) } if route.Hops[0].AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", route.Hops[0].AmtToForward, amt) } fee := route.HopFee(0) if fee != 0 { t.Fatalf("wrong hop fee: got %v, expected %v", fee, 0) } // The CLTV expiry should be the current height plus 9 (the expiry for // the B -> C channel. if route.TotalTimeLock != startingHeight+zpay32.DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", route.TotalTimeLock, startingHeight+zpay32.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(nil, 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 source.PubKeyBytes != alice { t.Fatalf("source node not set") } // We'll now request a route from A -> B -> C. route, err = ctx.router.FindRoute( source.PubKeyBytes, carol, amt, noRestrictions, nil, ) if err != nil { t.Fatalf("unable to find routes: %v", err) } // The route should be two hops. if len(route.Hops) != 2 { t.Fatalf("route should be %v hops, is instead %v", 2, len(route.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 route.TotalAmount != expectedAmt { t.Fatalf("wrong amount: got %v, expected %v", route.TotalAmount, expectedAmt) } if route.TotalTimeLock != startingHeight+29 { t.Fatalf("wrong total time lock: got %v, expecting %v", route.TotalTimeLock, startingHeight+29) } // Ensure that the hops of the route are properly crafted. // // After taking the fee, Bob should be forwarding the remainder which // is the exact payment to Bob. if route.Hops[0].AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", route.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 fee = route.HopFee(0) if fee != 10199 { t.Fatalf("wrong hop fee: got %v, expected %v", fee, 10199) } // While for the final hop, as there's no additional hop afterwards, we // pay no fee. fee = route.HopFee(1) if fee != 0 { t.Fatalf("wrong hop fee: got %v, expected %v", fee, 0) } // The outgoing CLTV value itself should be the current height plus 30 // to meet Carol's requirements. if route.Hops[0].OutgoingTimeLock != startingHeight+zpay32.DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", route.Hops[0].OutgoingTimeLock, startingHeight+zpay32.DefaultFinalCLTVDelta) } // For B -> C, we assert that the final hop also has the proper // parameters. lastHop := route.Hops[1] if lastHop.AmtToForward != amt { t.Fatalf("wrong forward amount: got %v, expected %v", lastHop.AmtToForward, amt) } if lastHop.OutgoingTimeLock != startingHeight+zpay32.DefaultFinalCLTVDelta { t.Fatalf("wrong total time lock: got %v, expecting %v", lastHop.OutgoingTimeLock, startingHeight+zpay32.DefaultFinalCLTVDelta) } } func assertExpectedPath(t *testing.T, aliasMap map[string]route.Vertex, path []*channeldb.ChannelEdgePolicy, 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.PubKeyBytes != aliasMap[nodeAliases[i]] { t.Fatalf("expected %v to be pos #%v in hop, instead "+ "%v was", nodeAliases[i], i, hop.Node.Alias) } } } // TestNewRouteFromEmptyHops tests that the NewRouteFromHops function returns an // error when the hop list is empty. func TestNewRouteFromEmptyHops(t *testing.T) { t.Parallel() var source route.Vertex _, err := route.NewRouteFromHops(0, 0, source, []*route.Hop{}) if err != route.ErrNoRouteHopsProvided { t.Fatalf("expected empty hops error: instead got: %v", err) } } // TestRestrictOutgoingChannel asserts that a outgoing channel restriction is // obeyed by the path finding algorithm. func TestRestrictOutgoingChannel(t *testing.T) { t.Parallel() // Set up a test graph with three possible paths from roasbeef to // target. The path through channel 2 is the highest cost path. testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "a", 100000, &testChannelPolicy{ Expiry: 144, }, 1), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, }, 4), symmetricTestChannel("roasbeef", "b", 100000, &testChannelPolicy{ Expiry: 144, }, 2), symmetricTestChannel("roasbeef", "b", 100000, &testChannelPolicy{ Expiry: 144, }, 3), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 800, }, 5), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() const ( startingHeight = 100 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") outgoingChannelID := uint64(2) // Find the best path given the restriction to only use channel 2 as the // outgoing channel. ctx.restrictParams.OutgoingChannelID = &outgoingChannelID path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( ctx.source, path, startingHeight, finalHopParams{ amt: paymentAmt, cltvDelta: finalHopCLTV, records: nil, }, ) if err != nil { t.Fatalf("unable to create path: %v", err) } // Assert that the route starts with channel 2, in line with the // specified restriction. if route.Hops[0].ChannelID != 2 { t.Fatalf("expected route to pass through channel 2, "+ "but channel %v was selected instead", route.Hops[0].ChannelID) } } // TestRestrictLastHop asserts that a last hop restriction is obeyed by the path // finding algorithm. func TestRestrictLastHop(t *testing.T) { t.Parallel() // Set up a test graph with three possible paths from roasbeef to // target. The path via channel 1 and 2 is the lowest cost path. testChannels := []*testChannel{ symmetricTestChannel("source", "a", 100000, &testChannelPolicy{ Expiry: 144, }, 1), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 400, }, 2), symmetricTestChannel("source", "b", 100000, &testChannelPolicy{ Expiry: 144, }, 3), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeRate: 800, }, 4), } ctx := newPathFindingTestContext(t, testChannels, "source") defer ctx.cleanup() paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") lastHop := ctx.keyFromAlias("b") // Find the best path given the restriction to use b as the last hop. // This should force pathfinding to not take the lowest cost option. ctx.restrictParams.LastHop = &lastHop path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } if path[0].ChannelID != 3 { t.Fatalf("expected route to pass through channel 3, "+ "but channel %v was selected instead", path[0].ChannelID) } } // TestCltvLimit asserts that a cltv limit is obeyed by the path finding // algorithm. func TestCltvLimit(t *testing.T) { t.Run("no limit", func(t *testing.T) { testCltvLimit(t, 2016, 1) }) t.Run("no path", func(t *testing.T) { testCltvLimit(t, 50, 0) }) t.Run("force high cost", func(t *testing.T) { testCltvLimit(t, 80, 3) }) } func testCltvLimit(t *testing.T, limit uint32, expectedChannel uint64) { t.Parallel() // Set up a test graph with three possible paths to the target. The path // through a is the lowest cost with a high time lock (144). The path // through b has a higher cost but a lower time lock (100). That path // through c and d (two hops) has the same case as the path through b, // but the total time lock is lower (60). testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "a", 100000, &testChannelPolicy{}, 1), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 10000, MinHTLC: 1, }), symmetricTestChannel("roasbeef", "b", 100000, &testChannelPolicy{}, 2), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 100, FeeBaseMsat: 20000, MinHTLC: 1, }), symmetricTestChannel("roasbeef", "c", 100000, &testChannelPolicy{}, 3), symmetricTestChannel("c", "d", 100000, &testChannelPolicy{ Expiry: 30, FeeBaseMsat: 10000, MinHTLC: 1, }), symmetricTestChannel("d", "target", 100000, &testChannelPolicy{ Expiry: 30, FeeBaseMsat: 10000, MinHTLC: 1, }), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") ctx.restrictParams.CltvLimit = limit path, err := ctx.findPath(target, paymentAmt) if expectedChannel == 0 { // Finish test if we expect no route. if err == errNoPathFound { return } t.Fatal("expected no path to be found") } if err != nil { t.Fatalf("unable to find path: %v", err) } const ( startingHeight = 100 finalHopCLTV = 1 ) route, err := newRoute( ctx.source, path, startingHeight, finalHopParams{ amt: paymentAmt, cltvDelta: finalHopCLTV, records: nil, }, ) if err != nil { t.Fatalf("unable to create path: %v", err) } // Assert that the route starts with the expected channel. if route.Hops[0].ChannelID != expectedChannel { t.Fatalf("expected route to pass through channel %v, "+ "but channel %v was selected instead", expectedChannel, route.Hops[0].ChannelID) } } // TestProbabilityRouting asserts that path finding not only takes into account // fees but also success probability. func TestProbabilityRouting(t *testing.T) { t.Parallel() testCases := []struct { name string p10, p11, p20 float64 minProbability float64 expectedChan uint64 }{ // Test two variations with probabilities that should multiply // to the same total route probability. In both cases the three // hop route should be the best route. The three hop route has a // probability of 0.5 * 0.8 = 0.4. The fee is 5 (chan 10) + 8 // (chan 11) = 13. Path finding distance should work out to: 13 // + 10 (attempt penalty) / 0.4 = 38. The two hop route is 25 + // 10 / 0.7 = 39. { name: "three hop 1", p10: 0.8, p11: 0.5, p20: 0.7, minProbability: 0.1, expectedChan: 10, }, { name: "three hop 2", p10: 0.5, p11: 0.8, p20: 0.7, minProbability: 0.1, expectedChan: 10, }, // If the probability of the two hop route is increased, its // distance becomes 25 + 10 / 0.85 = 37. This is less than the // three hop route with its distance 38. So with an attempt // penalty of 10, the higher fee route is chosen because of the // compensation for success probability. { name: "two hop higher cost", p10: 0.5, p11: 0.8, p20: 0.85, minProbability: 0.1, expectedChan: 20, }, // If the same probabilities are used with a probability lower bound of // 0.5, we expect the three hop route with probability 0.4 to be // excluded and the two hop route to be picked. { name: "probability limit", p10: 0.8, p11: 0.5, p20: 0.7, minProbability: 0.5, expectedChan: 20, }, // With a probability limit above the probability of both routes, we // expect no route to be returned. This expectation is signaled by using // expected channel 0. { name: "probability limit no routes", p10: 0.8, p11: 0.5, p20: 0.7, minProbability: 0.8, expectedChan: 0, }, } for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { testProbabilityRouting( t, tc.p10, tc.p11, tc.p20, tc.minProbability, tc.expectedChan, ) }) } } func testProbabilityRouting(t *testing.T, p10, p11, p20, minProbability float64, expectedChan uint64) { t.Parallel() // Set up a test graph with two possible paths to the target: a three // hop path (via channels 10 and 11) and a two hop path (via channel // 20). testChannels := []*testChannel{ symmetricTestChannel("roasbeef", "a1", 100000, &testChannelPolicy{}), symmetricTestChannel("roasbeef", "b", 100000, &testChannelPolicy{}), symmetricTestChannel("a1", "a2", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: lnwire.NewMSatFromSatoshis(5), MinHTLC: 1, }, 10), symmetricTestChannel("a2", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: lnwire.NewMSatFromSatoshis(8), MinHTLC: 1, }, 11), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 100, FeeBaseMsat: lnwire.NewMSatFromSatoshis(25), MinHTLC: 1, }, 20), } ctx := newPathFindingTestContext(t, testChannels, "roasbeef") defer ctx.cleanup() alias := ctx.testGraphInstance.aliasMap paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.testGraphInstance.aliasMap["target"] // Configure a probability source with the test parameters. ctx.restrictParams.ProbabilitySource = func(fromNode, toNode route.Vertex, amt lnwire.MilliSatoshi) float64 { if amt == 0 { t.Fatal("expected non-zero amount") } switch { case fromNode == alias["a1"] && toNode == alias["a2"]: return p10 case fromNode == alias["a2"] && toNode == alias["target"]: return p11 case fromNode == alias["b"] && toNode == alias["target"]: return p20 default: return 1 } } ctx.pathFindingConfig = PathFindingConfig{ PaymentAttemptPenalty: lnwire.NewMSatFromSatoshis(10), MinProbability: minProbability, } path, err := ctx.findPath(target, paymentAmt) if expectedChan == 0 { if err != errNoPathFound { t.Fatalf("expected no path found, but got %v", err) } return } if err != nil { t.Fatal(err) } // Assert that the route passes through the expected channel. if path[1].ChannelID != expectedChan { t.Fatalf("expected route to pass through channel %v, "+ "but channel %v was selected instead", expectedChan, path[1].ChannelID) } } // TestEqualCostRouteSelection asserts that route probability will be used as a // tie breaker in case the path finding probabilities are equal. func TestEqualCostRouteSelection(t *testing.T) { t.Parallel() // Set up a test graph with two possible paths to the target: via a and // via b. The routing fees and probabilities are chosen such that the // algorithm will first explore target->a->source (backwards search). // This route has fee 6 and a penality of 4 for the 25% success // probability. The algorithm will then proceed with evaluating // target->b->source, which has a fee of 8 and a penalty of 2 for the // 50% success probability. Both routes have the same path finding cost // of 10. It is expected that in that case, the highest probability // route (through b) is chosen. testChannels := []*testChannel{ symmetricTestChannel("source", "a", 100000, &testChannelPolicy{}), symmetricTestChannel("source", "b", 100000, &testChannelPolicy{}), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: lnwire.NewMSatFromSatoshis(6), MinHTLC: 1, }, 1), symmetricTestChannel("b", "target", 100000, &testChannelPolicy{ Expiry: 100, FeeBaseMsat: lnwire.NewMSatFromSatoshis(8), MinHTLC: 1, }, 2), } ctx := newPathFindingTestContext(t, testChannels, "source") defer ctx.cleanup() alias := ctx.testGraphInstance.aliasMap paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.testGraphInstance.aliasMap["target"] ctx.restrictParams.ProbabilitySource = func(fromNode, toNode route.Vertex, amt lnwire.MilliSatoshi) float64 { switch { case fromNode == alias["source"] && toNode == alias["a"]: return 0.25 case fromNode == alias["source"] && toNode == alias["b"]: return 0.5 default: return 1 } } ctx.pathFindingConfig = PathFindingConfig{ PaymentAttemptPenalty: lnwire.NewMSatFromSatoshis(1), } path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatal(err) } if path[1].ChannelID != 2 { t.Fatalf("expected route to pass through channel %v, "+ "but channel %v was selected instead", 2, path[1].ChannelID) } } // TestNoCycle tries to guide the path finding algorithm into reconstructing an // endless route. It asserts that the algorithm is able to handle this properly. func TestNoCycle(t *testing.T) { t.Parallel() // Set up a test graph with two paths: source->a->target and // source->b->c->target. The fees are setup such that, searching // backwards, the algorithm will evaluate the following end of the route // first: ->target->c->target. This does not make sense, because if // target is reached, there is no need to continue to c. A proper // implementation will then go on with alternative routes. It will then // consider ->a->target because its cost is lower than the alternative // ->b->c->target and finally find source->a->target as the best route. testChannels := []*testChannel{ symmetricTestChannel("source", "a", 100000, &testChannelPolicy{ Expiry: 144, }, 1), symmetricTestChannel("source", "b", 100000, &testChannelPolicy{ Expiry: 144, }, 2), symmetricTestChannel("b", "c", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 2000, }, 3), symmetricTestChannel("c", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 0, }, 4), symmetricTestChannel("a", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 600, }, 5), } ctx := newPathFindingTestContext(t, testChannels, "source") defer ctx.cleanup() const ( startingHeight = 100 finalHopCLTV = 1 ) paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") // Find the best path given the restriction to only use channel 2 as the // outgoing channel. path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } route, err := newRoute( ctx.source, path, startingHeight, finalHopParams{ amt: paymentAmt, cltvDelta: finalHopCLTV, records: nil, }, ) if err != nil { t.Fatalf("unable to create path: %v", err) } if len(route.Hops) != 2 { t.Fatalf("unexpected route") } if route.Hops[0].ChannelID != 1 { t.Fatalf("unexpected first hop") } if route.Hops[1].ChannelID != 5 { t.Fatalf("unexpected second hop") } } // TestRouteToSelf tests that it is possible to find a route to the self node. func TestRouteToSelf(t *testing.T) { t.Parallel() testChannels := []*testChannel{ symmetricTestChannel("source", "a", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 500, }, 1), symmetricTestChannel("source", "b", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 1000, }, 2), symmetricTestChannel("a", "b", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 1000, }, 3), } ctx := newPathFindingTestContext(t, testChannels, "source") defer ctx.cleanup() paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.source // Find the best path to self. We expect this to be source->a->source, // because a charges the lowest forwarding fee. path, err := ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } ctx.assertPath(path, []uint64{1, 1}) outgoingChanID := uint64(1) lastHop := ctx.keyFromAlias("b") ctx.restrictParams.OutgoingChannelID = &outgoingChanID ctx.restrictParams.LastHop = &lastHop // Find the best path to self given that we want to go out via channel 1 // and return through node b. path, err = ctx.findPath(target, paymentAmt) if err != nil { t.Fatalf("unable to find path: %v", err) } ctx.assertPath(path, []uint64{1, 3, 2}) } // TestInsufficientBalance tests that a dedicated error is returned for // insufficient local balance. func TestInsufficientBalance(t *testing.T) { t.Parallel() testChannels := []*testChannel{ symmetricTestChannel("source", "target", 100000, &testChannelPolicy{ Expiry: 144, FeeBaseMsat: 500, }, 1), } ctx := newPathFindingTestContext(t, testChannels, "source") defer ctx.cleanup() paymentAmt := lnwire.NewMSatFromSatoshis(100) target := ctx.keyFromAlias("target") ctx.graphParams.bandwidthHints = map[uint64]lnwire.MilliSatoshi{ 1: lnwire.NewMSatFromSatoshis(50), } // Find the best path to self. We expect this to be source->a->source, // because a charges the lowest forwarding fee. _, err := ctx.findPath(target, paymentAmt) if err != errInsufficientBalance { t.Fatalf("expected insufficient balance error, but got: %v", err) } } type pathFindingTestContext struct { t *testing.T graphParams graphParams restrictParams RestrictParams pathFindingConfig PathFindingConfig testGraphInstance *testGraphInstance source route.Vertex } func newPathFindingTestContext(t *testing.T, testChannels []*testChannel, source string) *pathFindingTestContext { testGraphInstance, err := createTestGraphFromChannels( testChannels, source, ) if err != nil { t.Fatalf("unable to create graph: %v", err) } sourceNode, err := testGraphInstance.graph.SourceNode() if err != nil { t.Fatalf("unable to fetch source node: %v", err) } ctx := &pathFindingTestContext{ t: t, testGraphInstance: testGraphInstance, source: route.Vertex(sourceNode.PubKeyBytes), pathFindingConfig: *testPathFindingConfig, graphParams: graphParams{ graph: testGraphInstance.graph, }, restrictParams: *noRestrictions, } return ctx } func (c *pathFindingTestContext) keyFromAlias(alias string) route.Vertex { return c.testGraphInstance.aliasMap[alias] } func (c *pathFindingTestContext) aliasFromKey(pubKey route.Vertex) string { for alias, key := range c.testGraphInstance.aliasMap { if key == pubKey { return alias } } return "" } func (c *pathFindingTestContext) cleanup() { c.testGraphInstance.cleanUp() } func (c *pathFindingTestContext) findPath(target route.Vertex, amt lnwire.MilliSatoshi) ([]*channeldb.ChannelEdgePolicy, error) { return findPath( &c.graphParams, &c.restrictParams, &c.pathFindingConfig, c.source, target, amt, 0, ) } func (c *pathFindingTestContext) assertPath(path []*channeldb.ChannelEdgePolicy, expected []uint64) { if len(path) != len(expected) { c.t.Fatalf("expected path of length %v, but got %v", len(expected), len(path)) } for i, edge := range path { if edge.ChannelID != expected[i] { c.t.Fatalf("expected hop %v to be channel %v, "+ "but got %v", i, expected[i], edge.ChannelID) } } }