lnd.xprv/routing/pathfind_test.go
2017-02-02 00:24:16 -08:00

411 lines
12 KiB
Go

package routing
import (
"encoding/hex"
"encoding/json"
"errors"
"io/ioutil"
"net"
"os"
"strings"
"testing"
"time"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/chaincfg/chainhash"
"github.com/roasbeef/btcd/wire"
"github.com/roasbeef/btcutil"
)
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 = "testdata/excessive_hops.json"
)
// testGraph is the struct which coresponds 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 float64 `json:"fee_rate"`
Capacity int64 `json:"capacity"`
}
// makeTestGraph creates a new instance of a channeldb.ChannelGraph for testing
// purposes. A callback which cleans up the created temporary directories is
// also returned and intended to be executed after the test completes.
func makeTestGraph() (*channeldb.ChannelGraph, func(), error) {
// First, create a temporary directory to be used for the duration of
// this test.
tempDirName, err := ioutil.TempDir("", "channeldb")
if err != nil {
return nil, nil, err
}
// Next, create channeldb for the first time.
cdb, err := channeldb.Open(tempDirName)
if err != nil {
return nil, nil, err
}
cleanUp := func() {
cdb.Close()
os.RemoveAll(tempDirName)
}
return cdb.ChannelGraph(), cleanUp, nil
}
// aliasMap is a map from a node's alias to its public key. This type is
// provided in order to allow easily look up from the human rememberable alias
// to an exact node's public key.
type aliasMap map[string]*btcec.PublicKey
// parseTestGraph returns a fully populated ChannelGraph given a path to a JSON
// file which encodes a test graph.
func parseTestGraph(path string) (*channeldb.ChannelGraph, func(), aliasMap, error) {
graphJson, err := ioutil.ReadFile(path)
if err != nil {
return nil, nil, nil, err
}
// First unmarshal the JSON graph into an instance of the testGraph
// struct. Using the struct tags created above in the struct, the JSON
// will be properly parsed into the struct above.
var g testGraph
if err := json.Unmarshal(graphJson, &g); err != nil {
return nil, nil, nil, err
}
// We'll use this fake address for the IP address of all the nodes in
// our tests. This value isn't needed for path finding so it doesn't
// need to be unique.
testAddr, err := net.ResolveTCPAddr("tcp", "192.0.0.1:8888")
if err != nil {
return nil, nil, nil, err
}
// Next, create a temporary graph database for usage within the test.
graph, cleanUp, err := makeTestGraph()
if err != nil {
return nil, nil, nil, err
}
aliasMap := make(map[string]*btcec.PublicKey)
var source *channeldb.LightningNode
// First we insert all the nodes within the graph as vertexes.
for _, node := range g.Nodes {
pubBytes, err := hex.DecodeString(node.PubKey)
if err != nil {
return nil, nil, nil, err
}
pub, err := btcec.ParsePubKey(pubBytes, btcec.S256())
if err != nil {
return nil, nil, nil, err
}
dbNode := &channeldb.LightningNode{
LastUpdate: time.Now(),
Address: testAddr,
PubKey: pub,
Alias: node.Alias,
}
// 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!")
} else {
// 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
}
}
// Set the selected source node
if err := graph.SetSourceNode(source); err != nil {
return nil, nil, nil, err
}
// With all the vertexes inserted, we can now insert the edges into the
// test graph.
for _, edge := range g.Edges {
node1Bytes, err := hex.DecodeString(edge.Node1)
if err != nil {
return nil, nil, nil, err
}
node1Pub, err := btcec.ParsePubKey(node1Bytes, btcec.S256())
if err != nil {
return nil, nil, nil, err
}
node2Bytes, err := hex.DecodeString(edge.Node2)
if err != nil {
return nil, nil, nil, err
}
node2Pub, err := btcec.ParsePubKey(node2Bytes, btcec.S256())
if err != nil {
return nil, nil, nil, err
}
fundingTXID := strings.Split(edge.ChannelPoint, ":")[0]
txidBytes, err := chainhash.NewHashFromStr(fundingTXID)
if err != nil {
return nil, nil, nil, err
}
fundingPoint := wire.OutPoint{
Hash: *txidBytes,
Index: 0,
}
// We first insert the existence of the edge between the two
// nodes.
if err := graph.AddChannelEdge(node1Pub, node2Pub, &fundingPoint,
edge.ChannelID); err != nil {
return nil, nil, nil, err
}
edge := &channeldb.ChannelEdge{
ChannelID: edge.ChannelID,
ChannelPoint: fundingPoint,
LastUpdate: time.Now(),
Expiry: edge.Expiry,
MinHTLC: btcutil.Amount(edge.MinHTLC),
FeeBaseMSat: btcutil.Amount(edge.FeeBaseMsat),
FeeProportionalMillionths: btcutil.Amount(edge.FeeRate),
Capacity: btcutil.Amount(edge.Capacity),
}
// As the graph itself is directed, we need to insert two edges
// into the graph: one from node1->node2 and one from
// node2->node1. A flag of 0 indicates this is the routing
// policy for the first node, and a flag of 1 indicates its the
// information for the second node.
edge.Flags = 0
if err := graph.UpdateEdgeInfo(edge); err != nil {
return nil, nil, nil, err
}
edge.Flags = 1
if err := graph.UpdateEdgeInfo(edge); err != nil {
return nil, nil, nil, err
}
}
return graph, cleanUp, aliasMap, nil
}
func TestBasicGraphPathFinding(t *testing.T) {
graph, cleanUp, aliases, err := parseTestGraph(basicGraphFilePath)
defer cleanUp()
if err != nil {
t.Fatalf("unable to create graph: %v", err)
}
// 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 paymentAmt = btcutil.Amount(100)
target := aliases["sophon"]
route, err := findRoute(graph, target, paymentAmt)
if err != nil {
t.Fatalf("unable to find route: %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 be two.
if route.TotalTimeLock != 2 {
t.Fatalf("expected time lock of %v, instead have %v", 2,
route.TotalTimeLock)
}
// The first hop in the path should be an edge from roasbeef to goku.
if !route.Hops[0].Channel.Node.PubKey.IsEqual(aliases["songoku"]) {
t.Fatalf("first hop should be goku, is instead: %v",
route.Hops[0].Channel.Node.Alias)
}
// WE shoul
// The second hop should be from goku to sophon.
if !route.Hops[1].Channel.Node.PubKey.IsEqual(aliases["sophon"]) {
t.Fatalf("second hop should be sophon, is instead: %v",
route.Hops[0].Channel.Node.Alias)
}
// Next, 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"]
route, err = findRoute(graph, target, paymentAmt)
if err != nil {
t.Fatalf("unable to find route: %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 one.
if route.TotalTimeLock != 1 {
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 TestNewRoutePathTooLong(t *testing.T) {
// 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)
}
const paymentAmt = btcutil.Amount(100)
// We start by confirminig that routing a payment 20 hops away is possible.
// Alice should be able to find a valid route to ursula.
target := aliases["ursula"]
route, err := findRoute(graph, target, paymentAmt)
if err != nil {
t.Fatalf("path should have been found")
}
// Vincent is 21 hops away from Alice, and thus no valid route should be
// presented to Alice.
target = aliases["vincent"]
route, err = findRoute(graph, target, paymentAmt)
if err == nil {
t.Fatalf("should not have been able to find path, supposed to be "+
"greater than 20 hops, found route with %v hops", len(route.Hops))
}
}
func TestPathNotAvailable(t *testing.T) {
graph, cleanUp, _, err := parseTestGraph(basicGraphFilePath)
defer cleanUp()
if err != nil {
t.Fatalf("unable to create graph: %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)
}
unknownNode, err := btcec.ParsePubKey(unknownNodeBytes, btcec.S256())
if err != nil {
t.Fatalf("unable to parse pubkey: %v", err)
}
if _, err := findRoute(graph, unknownNode, 100); err != ErrNoPathFound {
t.Fatalf("path shouldn't have been found: %v", err)
}
}
func TestPathInsufficientCapacity(t *testing.T) {
graph, cleanUp, aliases, err := parseTestGraph(basicGraphFilePath)
defer cleanUp()
if err != nil {
t.Fatalf("unable to create graph: %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 := aliases["sophon"]
const payAmt = btcutil.SatoshiPerBitcoin
_, err = findRoute(graph, target, payAmt)
if err != ErrInsufficientCapacity {
t.Fatalf("graph shouldn't be able to support payment: %v", err)
}
}
func TestPathInsufficientCapacityWithFee(t *testing.T) {
// TODO(roasbeef): encode live graph to json
}