go-pulse/p2p/discover/table_test.go
timcooijmans 7b5107b73f
p2p/discover: avoid dropping unverified nodes when table is almost empty (#21396)
This change improves discovery behavior in small networks. Very small
networks would often fail to bootstrap because all member nodes were
dropping table content due to findnode failure. The check is now changed
to avoid dropping nodes on findnode failure when their bucket is almost
empty. It also relaxes the liveness check requirement for FINDNODE/v4
response nodes, returning unverified nodes as results when there aren't
any verified nodes yet.

The "findnode failed" log now reports whether the node was dropped
instead of the number of results. The value of the "results" was
always zero by definition.

Co-authored-by: Felix Lange <fjl@twurst.com>
2020-08-24 14:42:39 +02:00

429 lines
12 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package discover
import (
"crypto/ecdsa"
"fmt"
"math/rand"
"net"
"reflect"
"testing"
"testing/quick"
"time"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
"github.com/ethereum/go-ethereum/p2p/netutil"
)
func TestTable_pingReplace(t *testing.T) {
run := func(newNodeResponding, lastInBucketResponding bool) {
name := fmt.Sprintf("newNodeResponding=%t/lastInBucketResponding=%t", newNodeResponding, lastInBucketResponding)
t.Run(name, func(t *testing.T) {
t.Parallel()
testPingReplace(t, newNodeResponding, lastInBucketResponding)
})
}
run(true, true)
run(false, true)
run(true, false)
run(false, false)
}
func testPingReplace(t *testing.T, newNodeIsResponding, lastInBucketIsResponding bool) {
transport := newPingRecorder()
tab, db := newTestTable(transport)
defer db.Close()
defer tab.close()
<-tab.initDone
// Fill up the sender's bucket.
pingKey, _ := crypto.HexToECDSA("45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8")
pingSender := wrapNode(enode.NewV4(&pingKey.PublicKey, net.IP{127, 0, 0, 1}, 99, 99))
last := fillBucket(tab, pingSender)
// Add the sender as if it just pinged us. Revalidate should replace the last node in
// its bucket if it is unresponsive. Revalidate again to ensure that
transport.dead[last.ID()] = !lastInBucketIsResponding
transport.dead[pingSender.ID()] = !newNodeIsResponding
tab.addSeenNode(pingSender)
tab.doRevalidate(make(chan struct{}, 1))
tab.doRevalidate(make(chan struct{}, 1))
if !transport.pinged[last.ID()] {
// Oldest node in bucket is pinged to see whether it is still alive.
t.Error("table did not ping last node in bucket")
}
tab.mutex.Lock()
defer tab.mutex.Unlock()
wantSize := bucketSize
if !lastInBucketIsResponding && !newNodeIsResponding {
wantSize--
}
if l := len(tab.bucket(pingSender.ID()).entries); l != wantSize {
t.Errorf("wrong bucket size after bond: got %d, want %d", l, wantSize)
}
if found := contains(tab.bucket(pingSender.ID()).entries, last.ID()); found != lastInBucketIsResponding {
t.Errorf("last entry found: %t, want: %t", found, lastInBucketIsResponding)
}
wantNewEntry := newNodeIsResponding && !lastInBucketIsResponding
if found := contains(tab.bucket(pingSender.ID()).entries, pingSender.ID()); found != wantNewEntry {
t.Errorf("new entry found: %t, want: %t", found, wantNewEntry)
}
}
func TestBucket_bumpNoDuplicates(t *testing.T) {
t.Parallel()
cfg := &quick.Config{
MaxCount: 1000,
Rand: rand.New(rand.NewSource(time.Now().Unix())),
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] = nodeAtDistance(enode.ID{}, 200, intIP(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) {
tab, db := newTestTable(newPingRecorder())
defer db.Close()
defer tab.close()
b := &bucket{entries: make([]*node, len(nodes))}
copy(b.entries, nodes)
for i, pos := range bumps {
tab.bumpInBucket(b, 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
}
}
checkIPLimitInvariant(t, tab)
return true
}
if err := quick.Check(prop, cfg); err != nil {
t.Error(err)
}
}
// This checks that the table-wide IP limit is applied correctly.
func TestTable_IPLimit(t *testing.T) {
transport := newPingRecorder()
tab, db := newTestTable(transport)
defer db.Close()
defer tab.close()
for i := 0; i < tableIPLimit+1; i++ {
n := nodeAtDistance(tab.self().ID(), i, net.IP{172, 0, 1, byte(i)})
tab.addSeenNode(n)
}
if tab.len() > tableIPLimit {
t.Errorf("too many nodes in table")
}
checkIPLimitInvariant(t, tab)
}
// This checks that the per-bucket IP limit is applied correctly.
func TestTable_BucketIPLimit(t *testing.T) {
transport := newPingRecorder()
tab, db := newTestTable(transport)
defer db.Close()
defer tab.close()
d := 3
for i := 0; i < bucketIPLimit+1; i++ {
n := nodeAtDistance(tab.self().ID(), d, net.IP{172, 0, 1, byte(i)})
tab.addSeenNode(n)
}
if tab.len() > bucketIPLimit {
t.Errorf("too many nodes in table")
}
checkIPLimitInvariant(t, tab)
}
// checkIPLimitInvariant checks that ip limit sets contain an entry for every
// node in the table and no extra entries.
func checkIPLimitInvariant(t *testing.T, tab *Table) {
t.Helper()
tabset := netutil.DistinctNetSet{Subnet: tableSubnet, Limit: tableIPLimit}
for _, b := range tab.buckets {
for _, n := range b.entries {
tabset.Add(n.IP())
}
}
if tabset.String() != tab.ips.String() {
t.Errorf("table IP set is incorrect:\nhave: %v\nwant: %v", tab.ips, tabset)
}
}
func TestTable_findnodeByID(t *testing.T) {
t.Parallel()
test := func(test *closeTest) bool {
// for any node table, Target and N
transport := newPingRecorder()
tab, db := newTestTable(transport)
defer db.Close()
defer tab.close()
fillTable(tab, test.All)
// check that closest(Target, N) returns nodes
result := tab.findnodeByID(test.Target, test.N, false).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 enode.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)
}
}
func TestTable_ReadRandomNodesGetAll(t *testing.T) {
cfg := &quick.Config{
MaxCount: 200,
Rand: rand.New(rand.NewSource(time.Now().Unix())),
Values: func(args []reflect.Value, rand *rand.Rand) {
args[0] = reflect.ValueOf(make([]*enode.Node, rand.Intn(1000)))
},
}
test := func(buf []*enode.Node) bool {
transport := newPingRecorder()
tab, db := newTestTable(transport)
defer db.Close()
defer tab.close()
<-tab.initDone
for i := 0; i < len(buf); i++ {
ld := cfg.Rand.Intn(len(tab.buckets))
fillTable(tab, []*node{nodeAtDistance(tab.self().ID(), ld, intIP(ld))})
}
gotN := tab.ReadRandomNodes(buf)
if gotN != tab.len() {
t.Errorf("wrong number of nodes, got %d, want %d", gotN, tab.len())
return false
}
if hasDuplicates(wrapNodes(buf[:gotN])) {
t.Errorf("result contains duplicates")
return false
}
return true
}
if err := quick.Check(test, cfg); err != nil {
t.Error(err)
}
}
type closeTest struct {
Self enode.ID
Target enode.ID
All []*node
N int
}
func (*closeTest) Generate(rand *rand.Rand, size int) reflect.Value {
t := &closeTest{
Self: gen(enode.ID{}, rand).(enode.ID),
Target: gen(enode.ID{}, rand).(enode.ID),
N: rand.Intn(bucketSize),
}
for _, id := range gen([]enode.ID{}, rand).([]enode.ID) {
r := new(enr.Record)
r.Set(enr.IP(genIP(rand)))
n := wrapNode(enode.SignNull(r, id))
n.livenessChecks = 1
t.All = append(t.All, n)
}
return reflect.ValueOf(t)
}
func TestTable_addVerifiedNode(t *testing.T) {
tab, db := newTestTable(newPingRecorder())
<-tab.initDone
defer db.Close()
defer tab.close()
// Insert two nodes.
n1 := nodeAtDistance(tab.self().ID(), 256, net.IP{88, 77, 66, 1})
n2 := nodeAtDistance(tab.self().ID(), 256, net.IP{88, 77, 66, 2})
tab.addSeenNode(n1)
tab.addSeenNode(n2)
// Verify bucket content:
bcontent := []*node{n1, n2}
if !reflect.DeepEqual(tab.bucket(n1.ID()).entries, bcontent) {
t.Fatalf("wrong bucket content: %v", tab.bucket(n1.ID()).entries)
}
// Add a changed version of n2.
newrec := n2.Record()
newrec.Set(enr.IP{99, 99, 99, 99})
newn2 := wrapNode(enode.SignNull(newrec, n2.ID()))
tab.addVerifiedNode(newn2)
// Check that bucket is updated correctly.
newBcontent := []*node{newn2, n1}
if !reflect.DeepEqual(tab.bucket(n1.ID()).entries, newBcontent) {
t.Fatalf("wrong bucket content after update: %v", tab.bucket(n1.ID()).entries)
}
checkIPLimitInvariant(t, tab)
}
func TestTable_addSeenNode(t *testing.T) {
tab, db := newTestTable(newPingRecorder())
<-tab.initDone
defer db.Close()
defer tab.close()
// Insert two nodes.
n1 := nodeAtDistance(tab.self().ID(), 256, net.IP{88, 77, 66, 1})
n2 := nodeAtDistance(tab.self().ID(), 256, net.IP{88, 77, 66, 2})
tab.addSeenNode(n1)
tab.addSeenNode(n2)
// Verify bucket content:
bcontent := []*node{n1, n2}
if !reflect.DeepEqual(tab.bucket(n1.ID()).entries, bcontent) {
t.Fatalf("wrong bucket content: %v", tab.bucket(n1.ID()).entries)
}
// Add a changed version of n2.
newrec := n2.Record()
newrec.Set(enr.IP{99, 99, 99, 99})
newn2 := wrapNode(enode.SignNull(newrec, n2.ID()))
tab.addSeenNode(newn2)
// Check that bucket content is unchanged.
if !reflect.DeepEqual(tab.bucket(n1.ID()).entries, bcontent) {
t.Fatalf("wrong bucket content after update: %v", tab.bucket(n1.ID()).entries)
}
checkIPLimitInvariant(t, tab)
}
// This test checks that ENR updates happen during revalidation. If a node in the table
// announces a new sequence number, the new record should be pulled.
func TestTable_revalidateSyncRecord(t *testing.T) {
transport := newPingRecorder()
tab, db := newTestTable(transport)
<-tab.initDone
defer db.Close()
defer tab.close()
// Insert a node.
var r enr.Record
r.Set(enr.IP(net.IP{127, 0, 0, 1}))
id := enode.ID{1}
n1 := wrapNode(enode.SignNull(&r, id))
tab.addSeenNode(n1)
// Update the node record.
r.Set(enr.WithEntry("foo", "bar"))
n2 := enode.SignNull(&r, id)
transport.updateRecord(n2)
tab.doRevalidate(make(chan struct{}, 1))
intable := tab.getNode(id)
if !reflect.DeepEqual(intable, n2) {
t.Fatalf("table contains old record with seq %d, want seq %d", intable.Seq(), n2.Seq())
}
}
// 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 genIP(rand *rand.Rand) net.IP {
ip := make(net.IP, 4)
rand.Read(ip)
return ip
}
func quickcfg() *quick.Config {
return &quick.Config{
MaxCount: 5000,
Rand: rand.New(rand.NewSource(time.Now().Unix())),
}
}
func newkey() *ecdsa.PrivateKey {
key, err := crypto.GenerateKey()
if err != nil {
panic("couldn't generate key: " + err.Error())
}
return key
}