package discover
import (
"crypto/ecdsa"
"errors"
"fmt"
"math/big"
"math/rand"
"net"
"reflect"
"testing"
"testing/quick"
"time"
"github.com/ethereum/go-ethereum/crypto"
)
var (
quickrand = rand.New(rand.NewSource(time.Now().Unix()))
quickcfg = &quick.Config{MaxCount: 5000, Rand: quickrand}
)
func TestHexID(t *testing.T) {
ref := NodeID{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, 0, 0, 0, 0, 0, 0, 0, 0, 128, 106, 217, 182, 31, 165, 174, 1, 67, 7, 235, 220, 150, 66, 83, 173, 205, 159, 44, 10, 57, 42, 161, 26, 188}
id1 := MustHexID("0x000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
id2 := MustHexID("000000000000000000000000000000000000000000000000000000000000000000000000000000806ad9b61fa5ae014307ebdc964253adcd9f2c0a392aa11abc")
if id1 != ref {
t.Errorf("wrong id1\ngot %v\nwant %v", id1[:], ref[:])
}
if id2 != ref {
t.Errorf("wrong id2\ngot %v\nwant %v", id2[:], ref[:])
}
}
func TestNodeID_recover(t *testing.T) {
prv := newkey()
hash := make([]byte, 32)
sig, err := crypto.Sign(hash, prv)
if err != nil {
t.Fatalf("signing error: %v", err)
}
pub := PubkeyID(&prv.PublicKey)
recpub, err := recoverNodeID(hash, sig)
if err != nil {
t.Fatalf("recovery error: %v", err)
}
if pub != recpub {
t.Errorf("recovered wrong pubkey:\ngot: %v\nwant: %v", recpub, pub)
}
}
func TestNodeID_distcmp(t *testing.T) {
distcmpBig := func(target, a, b NodeID) int {
tbig := new(big.Int).SetBytes(target[:])
abig := new(big.Int).SetBytes(a[:])
bbig := new(big.Int).SetBytes(b[:])
return new(big.Int).Xor(tbig, abig).Cmp(new(big.Int).Xor(tbig, bbig))
}
if err := quick.CheckEqual(distcmp, distcmpBig, quickcfg); err != nil {
t.Error(err)
}
}
// the random tests is likely to miss the case where they're equal.
func TestNodeID_distcmpEqual(t *testing.T) {
base := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
x := NodeID{15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
if distcmp(base, x, x) != 0 {
t.Errorf("distcmp(base, x, x) != 0")
}
}
func TestNodeID_logdist(t *testing.T) {
logdistBig := func(a, b NodeID) int {
abig, bbig := new(big.Int).SetBytes(a[:]), new(big.Int).SetBytes(b[:])
return new(big.Int).Xor(abig, bbig).BitLen()
}
if err := quick.CheckEqual(logdist, logdistBig, quickcfg); err != nil {
t.Error(err)
}
}
// the random tests is likely to miss the case where they're equal.
func TestNodeID_logdistEqual(t *testing.T) {
x := NodeID{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
if logdist(x, x) != 0 {
t.Errorf("logdist(x, x) != 0")
}
}
func TestNodeID_randomID(t *testing.T) {
// we don't use quick.Check here because its output isn't
// very helpful when the test fails.
for i := 0; i < quickcfg.MaxCount; i++ {
a := gen(NodeID{}, quickrand).(NodeID)
dist := quickrand.Intn(len(NodeID{}) * 8)
result := randomID(a, dist)
actualdist := logdist(result, a)
if dist != actualdist {
t.Log("a: ", a)
t.Log("result:", result)
t.Fatalf("#%d: distance of result is %d, want %d", i, actualdist, dist)
}
}
}
func (NodeID) Generate(rand *rand.Rand, size int) reflect.Value {
var id NodeID
m := rand.Intn(len(id))
for i := len(id) - 1; i > m; i-- {
id[i] = byte(rand.Uint32())
}
return reflect.ValueOf(id)
}
func TestTable_bumpOrAddPingReplace(t *testing.T) {
pingC := make(pingC)
tab := newTable(pingC, NodeID{}, &net.UDPAddr{})
last := fillBucket(tab, 200)
// this bumpOrAdd should not replace the last node
// because the node replies to ping.
new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
pinged := <-pingC
if pinged != last.ID {
t.Fatalf("pinged wrong node: %v\nwant %v", pinged, last.ID)
}
tab.mutex.Lock()
defer tab.mutex.Unlock()
if l := len(tab.buckets[200].entries); l != bucketSize {
t.Errorf("wrong bucket size after bumpOrAdd: got %d, want %d", bucketSize, l)
}
if !contains(tab.buckets[200].entries, last.ID) {
t.Error("last entry was removed")
}
if contains(tab.buckets[200].entries, new.ID) {
t.Error("new entry was added")
}
}
func TestTable_bumpOrAddPingTimeout(t *testing.T) {
tab := newTable(pingC(nil), NodeID{}, &net.UDPAddr{})
last := fillBucket(tab, 200)
// this bumpOrAdd should replace the last node
// because the node does not reply to ping.
new := tab.bumpOrAdd(randomID(tab.self.ID, 200), nil)
// wait for async bucket update. damn. this needs to go away.
time.Sleep(2 * time.Millisecond)
tab.mutex.Lock()
defer tab.mutex.Unlock()
if l := len(tab.buckets[200].entries); l != bucketSize {
t.Errorf("wrong bucket size after bumpOrAdd: got %d, want %d", bucketSize, l)
}
if contains(tab.buckets[200].entries, last.ID) {
t.Error("last entry was not removed")
}
if !contains(tab.buckets[200].entries, new.ID) {
t.Error("new entry was not added")
}
}
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 pingC chan NodeID
func (t pingC) findnode(n *Node, target NodeID) ([]*Node, error) {
panic("findnode called on pingRecorder")
}
func (t pingC) close() {
panic("close called on pingRecorder")
}
func (t pingC) ping(n *Node) error {
if t == nil {
return errTimeout
}
t <- n.ID
return nil
}
func TestTable_bump(t *testing.T) {
tab := newTable(nil, NodeID{}, &net.UDPAddr{})
// add an old entry and two recent ones
oldactive := time.Now().Add(-2 * time.Minute)
old := &Node{ID: randomID(tab.self.ID, 200), active: oldactive}
others := []*Node{
&Node{ID: randomID(tab.self.ID, 200), active: time.Now()},
&Node{ID: randomID(tab.self.ID, 200), active: time.Now()},
}
tab.add(append(others, old))
if tab.buckets[200].entries[0] == old {
t.Fatal("old entry is at front of bucket")
}
// bumping the old entry should move it to the front
tab.bump(old.ID)
if old.active == oldactive {
t.Error("activity timestamp not updated")
}
if tab.buckets[200].entries[0] != old {
t.Errorf("bumped entry did not move to the front of bucket")
}
}
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.bumpOrAdd(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(n *Node, target NodeID) ([]*Node, error) {
t.t.Logf("findnode query at dist %d", n.Addr.Port)
// current log distance is encoded in port number
var result []*Node
switch port := n.Addr.Port; port {
case 0:
panic("query to node at distance 0")
case 1:
result = append(result, &Node{ID: t.target, Addr: &net.UDPAddr{Port: 0}})
default:
// TODO: add more randomness to distances
port--
for i := 0; i < bucketSize; i++ {
result = append(result, &Node{ID: randomID(t.target, port), Addr: &net.UDPAddr{Port: port}})
}
}
return result, nil
}
func (t findnodeOracle) close() {}
func (t findnodeOracle) ping(n *Node) error {
return errors.New("ping is not supported by this transport")
}
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
}
