package discover import ( "crypto/ecdsa" "fmt" "math/rand" "net" "reflect" "testing" "testing/quick" "github.com/ethereum/go-ethereum/crypto" ) func TestTable_pingReplace(t *testing.T) { doit := func(newNodeIsResponding, lastInBucketIsResponding bool) { transport := newPingRecorder() tab := newTable(transport, NodeID{}, &net.UDPAddr{}, "") last := fillBucket(tab, 200) pingSender := randomID(tab.self.ID, 200) // this gotPing should replace the last node // if the last node is not responding. transport.responding[last.ID] = lastInBucketIsResponding transport.responding[pingSender] = newNodeIsResponding tab.bond(true, pingSender, &net.UDPAddr{}, 0) // first ping goes to sender (bonding pingback) if !transport.pinged[pingSender] { t.Error("table did not ping back sender") } if newNodeIsResponding { // second ping goes to oldest node in bucket // to see whether it is still alive. if !transport.pinged[last.ID] { t.Error("table did not ping last node in bucket") } } tab.mutex.Lock() defer tab.mutex.Unlock() if l := len(tab.buckets[200].entries); l != bucketSize { t.Errorf("wrong bucket size after gotPing: got %d, want %d", bucketSize, l) } if lastInBucketIsResponding || !newNodeIsResponding { if !contains(tab.buckets[200].entries, last.ID) { t.Error("last entry was removed") } if contains(tab.buckets[200].entries, pingSender) { t.Error("new entry was added") } } else { if contains(tab.buckets[200].entries, last.ID) { t.Error("last entry was not removed") } if !contains(tab.buckets[200].entries, pingSender) { t.Error("new entry was not added") } } } doit(true, true) doit(false, true) doit(false, true) doit(false, false) } func TestBucket_bumpNoDuplicates(t *testing.T) { t.Parallel() cfg := &quick.Config{ MaxCount: 1000, Rand: quickrand, Values: func(args []reflect.Value, rand *rand.Rand) { // generate a random list of nodes. this will be the content of the bucket. n := rand.Intn(bucketSize-1) + 1 nodes := make([]*Node, n) for i := range nodes { nodes[i] = &Node{ID: randomID(NodeID{}, 200)} } args[0] = reflect.ValueOf(nodes) // generate random bump positions. bumps := make([]int, rand.Intn(100)) for i := range bumps { bumps[i] = rand.Intn(len(nodes)) } args[1] = reflect.ValueOf(bumps) }, } prop := func(nodes []*Node, bumps []int) (ok bool) { b := &bucket{entries: make([]*Node, len(nodes))} copy(b.entries, nodes) for i, pos := range bumps { b.bump(b.entries[pos]) if hasDuplicates(b.entries) { t.Logf("bucket has duplicates after %d/%d bumps:", i+1, len(bumps)) for _, n := range b.entries { t.Logf(" %p", n) } return false } } return true } if err := quick.Check(prop, cfg); err != nil { t.Error(err) } } func fillBucket(tab *Table, ld int) (last *Node) { b := tab.buckets[ld] for len(b.entries) < bucketSize { b.entries = append(b.entries, &Node{ID: randomID(tab.self.ID, ld)}) } return b.entries[bucketSize-1] } type pingRecorder struct{ responding, pinged map[NodeID]bool } func newPingRecorder() *pingRecorder { return &pingRecorder{make(map[NodeID]bool), make(map[NodeID]bool)} } func (t *pingRecorder) findnode(toid NodeID, toaddr *net.UDPAddr, target NodeID) ([]*Node, error) { panic("findnode called on pingRecorder") } func (t *pingRecorder) close() { panic("close called on pingRecorder") } func (t *pingRecorder) waitping(from NodeID) error { return nil // remote always pings } func (t *pingRecorder) ping(toid NodeID, toaddr *net.UDPAddr) error { t.pinged[toid] = true if t.responding[toid] { return nil } else { return errTimeout } } func TestTable_closest(t *testing.T) { t.Parallel() test := func(test *closeTest) bool { // for any node table, Target and N tab := newTable(nil, test.Self, &net.UDPAddr{}, "") tab.add(test.All) // check that doClosest(Target, N) returns nodes result := tab.closest(test.Target, test.N).entries if hasDuplicates(result) { t.Errorf("result contains duplicates") return false } if !sortedByDistanceTo(test.Target, result) { t.Errorf("result is not sorted by distance to target") return false } // check that the number of results is min(N, tablen) wantN := test.N if tlen := tab.len(); tlen < test.N { wantN = tlen } if len(result) != wantN { t.Errorf("wrong number of nodes: got %d, want %d", len(result), wantN) return false } else if len(result) == 0 { return true // no need to check distance } // check that the result nodes have minimum distance to target. for _, b := range tab.buckets { for _, n := range b.entries { if contains(result, n.ID) { continue // don't run the check below for nodes in result } farthestResult := result[len(result)-1].ID if distcmp(test.Target, n.ID, farthestResult) < 0 { t.Errorf("table contains node that is closer to target but it's not in result") t.Logf(" Target: %v", test.Target) t.Logf(" Farthest Result: %v", farthestResult) t.Logf(" ID: %v", n.ID) return false } } } return true } if err := quick.Check(test, quickcfg); err != nil { t.Error(err) } } type closeTest struct { Self NodeID Target NodeID All []*Node N int } func (*closeTest) Generate(rand *rand.Rand, size int) reflect.Value { t := &closeTest{ Self: gen(NodeID{}, rand).(NodeID), Target: gen(NodeID{}, rand).(NodeID), N: rand.Intn(bucketSize), } for _, id := range gen([]NodeID{}, rand).([]NodeID) { t.All = append(t.All, &Node{ID: id}) } return reflect.ValueOf(t) } func TestTable_Lookup(t *testing.T) { self := gen(NodeID{}, quickrand).(NodeID) target := randomID(self, 200) transport := findnodeOracle{t, target} tab := newTable(transport, self, &net.UDPAddr{}, "") // lookup on empty table returns no nodes if results := tab.Lookup(target); len(results) > 0 { t.Fatalf("lookup on empty table returned %d results: %#v", len(results), results) } // seed table with initial node (otherwise lookup will terminate immediately) tab.add([]*Node{newNode(randomID(target, 200), &net.UDPAddr{Port: 200})}) results := tab.Lookup(target) t.Logf("results:") for _, e := range results { t.Logf(" ld=%d, %v", logdist(target, e.ID), e.ID) } if len(results) != bucketSize { t.Errorf("wrong number of results: got %d, want %d", len(results), bucketSize) } if hasDuplicates(results) { t.Errorf("result set contains duplicate entries") } if !sortedByDistanceTo(target, results) { t.Errorf("result set not sorted by distance to target") } if !contains(results, target) { t.Errorf("result set does not contain target") } } // findnode on this transport always returns at least one node // that is one bucket closer to the target. type findnodeOracle struct { t *testing.T target NodeID } func (t findnodeOracle) findnode(toid NodeID, toaddr *net.UDPAddr, target NodeID) ([]*Node, error) { t.t.Logf("findnode query at dist %d", toaddr.Port) // current log distance is encoded in port number var result []*Node switch toaddr.Port { case 0: panic("query to node at distance 0") default: // TODO: add more randomness to distances next := uint16(toaddr.Port) - 1 for i := 0; i < bucketSize; i++ { result = append(result, &Node{ID: randomID(t.target, int(next)), UDP: next}) } } return result, nil } func (t findnodeOracle) close() {} func (t findnodeOracle) waitping(from NodeID) error { return nil } func (t findnodeOracle) ping(toid NodeID, toaddr *net.UDPAddr) error { return nil } func hasDuplicates(slice []*Node) bool { seen := make(map[NodeID]bool) for _, e := range slice { if seen[e.ID] { return true } seen[e.ID] = true } return false } func sortedByDistanceTo(distbase NodeID, slice []*Node) bool { var last NodeID for i, e := range slice { if i > 0 && distcmp(distbase, e.ID, last) < 0 { return false } last = e.ID } return true } func contains(ns []*Node, id NodeID) bool { for _, n := range ns { if n.ID == id { return true } } return false } // gen wraps quick.Value so it's easier to use. // it generates a random value of the given value's type. func gen(typ interface{}, rand *rand.Rand) interface{} { v, ok := quick.Value(reflect.TypeOf(typ), rand) if !ok { panic(fmt.Sprintf("couldn't generate random value of type %T", typ)) } return v.Interface() } func newkey() *ecdsa.PrivateKey { key, err := crypto.GenerateKey() if err != nil { panic("couldn't generate key: " + err.Error()) } return key }