Official Go implementation of the Ethereum protocol
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go-ethereum/cmd/devp2p/internal/v5test/discv5tests.go

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// Copyright 2020 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package v5test
import (
"bytes"
"net"
"sync"
"time"
"github.com/ethereum/go-ethereum/internal/utesting"
"github.com/ethereum/go-ethereum/p2p/discover/v5wire"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/netutil"
)
// Suite is the discv5 test suite.
type Suite struct {
Dest *enode.Node
Listen1, Listen2 string // listening addresses
}
func (s *Suite) listen1(log logger) (*conn, net.PacketConn) {
c := newConn(s.Dest, log)
l := c.listen(s.Listen1)
return c, l
}
func (s *Suite) listen2(log logger) (*conn, net.PacketConn, net.PacketConn) {
c := newConn(s.Dest, log)
l1, l2 := c.listen(s.Listen1), c.listen(s.Listen2)
return c, l1, l2
}
func (s *Suite) AllTests() []utesting.Test {
return []utesting.Test{
{Name: "Ping", Fn: s.TestPing},
{Name: "PingLargeRequestID", Fn: s.TestPingLargeRequestID},
{Name: "PingMultiIP", Fn: s.TestPingMultiIP},
{Name: "PingHandshakeInterrupted", Fn: s.TestPingHandshakeInterrupted},
{Name: "TalkRequest", Fn: s.TestTalkRequest},
{Name: "FindnodeZeroDistance", Fn: s.TestFindnodeZeroDistance},
{Name: "FindnodeResults", Fn: s.TestFindnodeResults},
}
}
// This test sends PING and expects a PONG response.
func (s *Suite) TestPing(t *utesting.T) {
conn, l1 := s.listen1(t)
defer conn.close()
ping := &v5wire.Ping{ReqID: conn.nextReqID()}
switch resp := conn.reqresp(l1, ping).(type) {
case *v5wire.Pong:
checkPong(t, resp, ping, l1)
default:
t.Fatal("expected PONG, got", resp.Name())
}
}
func checkPong(t *utesting.T, pong *v5wire.Pong, ping *v5wire.Ping, c net.PacketConn) {
if !bytes.Equal(pong.ReqID, ping.ReqID) {
t.Fatalf("wrong request ID %x in PONG, want %x", pong.ReqID, ping.ReqID)
}
if !pong.ToIP.Equal(laddr(c).IP) {
t.Fatalf("wrong destination IP %v in PONG, want %v", pong.ToIP, laddr(c).IP)
}
if int(pong.ToPort) != laddr(c).Port {
t.Fatalf("wrong destination port %v in PONG, want %v", pong.ToPort, laddr(c).Port)
}
}
// This test sends PING with a 9-byte request ID, which isn't allowed by the spec.
// The remote node should not respond.
func (s *Suite) TestPingLargeRequestID(t *utesting.T) {
conn, l1 := s.listen1(t)
defer conn.close()
ping := &v5wire.Ping{ReqID: make([]byte, 9)}
switch resp := conn.reqresp(l1, ping).(type) {
case *v5wire.Pong:
t.Errorf("PONG response with unknown request ID %x", resp.ReqID)
case *readError:
if resp.err == v5wire.ErrInvalidReqID {
t.Error("response with oversized request ID")
} else if !netutil.IsTimeout(resp.err) {
t.Error(resp)
}
}
}
// In this test, a session is established from one IP as usual. The session is then reused
// on another IP, which shouldn't work. The remote node should respond with WHOAREYOU for
// the attempt from a different IP.
func (s *Suite) TestPingMultiIP(t *utesting.T) {
conn, l1, l2 := s.listen2(t)
defer conn.close()
// Create the session on l1.
ping := &v5wire.Ping{ReqID: conn.nextReqID()}
resp := conn.reqresp(l1, ping)
if resp.Kind() != v5wire.PongMsg {
t.Fatal("expected PONG, got", resp)
}
checkPong(t, resp.(*v5wire.Pong), ping, l1)
// Send on l2. This reuses the session because there is only one codec.
ping2 := &v5wire.Ping{ReqID: conn.nextReqID()}
conn.write(l2, ping2, nil)
switch resp := conn.read(l2).(type) {
case *v5wire.Pong:
t.Fatalf("remote responded to PING from %v for session on IP %v", laddr(l2).IP, laddr(l1).IP)
case *v5wire.Whoareyou:
t.Logf("got WHOAREYOU for new session as expected")
resp.Node = s.Dest
conn.write(l2, ping2, resp)
default:
t.Fatal("expected WHOAREYOU, got", resp)
}
// Catch the PONG on l2.
switch resp := conn.read(l2).(type) {
case *v5wire.Pong:
checkPong(t, resp, ping2, l2)
default:
t.Fatal("expected PONG, got", resp)
}
// Try on l1 again.
ping3 := &v5wire.Ping{ReqID: conn.nextReqID()}
conn.write(l1, ping3, nil)
switch resp := conn.read(l1).(type) {
case *v5wire.Pong:
t.Fatalf("remote responded to PING from %v for session on IP %v", laddr(l1).IP, laddr(l2).IP)
case *v5wire.Whoareyou:
t.Logf("got WHOAREYOU for new session as expected")
default:
t.Fatal("expected WHOAREYOU, got", resp)
}
}
// This test starts a handshake, but doesn't finish it and sends a second ordinary message
// packet instead of a handshake message packet. The remote node should respond with
// another WHOAREYOU challenge for the second packet.
func (s *Suite) TestPingHandshakeInterrupted(t *utesting.T) {
conn, l1 := s.listen1(t)
defer conn.close()
// First PING triggers challenge.
ping := &v5wire.Ping{ReqID: conn.nextReqID()}
conn.write(l1, ping, nil)
switch resp := conn.read(l1).(type) {
case *v5wire.Whoareyou:
t.Logf("got WHOAREYOU for PING")
default:
t.Fatal("expected WHOAREYOU, got", resp)
}
// Send second PING.
ping2 := &v5wire.Ping{ReqID: conn.nextReqID()}
switch resp := conn.reqresp(l1, ping2).(type) {
case *v5wire.Pong:
checkPong(t, resp, ping2, l1)
default:
t.Fatal("expected WHOAREYOU, got", resp)
}
}
// This test sends TALKREQ and expects an empty TALKRESP response.
func (s *Suite) TestTalkRequest(t *utesting.T) {
conn, l1 := s.listen1(t)
defer conn.close()
// Non-empty request ID.
id := conn.nextReqID()
resp := conn.reqresp(l1, &v5wire.TalkRequest{ReqID: id, Protocol: "test-protocol"})
switch resp := resp.(type) {
case *v5wire.TalkResponse:
if !bytes.Equal(resp.ReqID, id) {
t.Fatalf("wrong request ID %x in TALKRESP, want %x", resp.ReqID, id)
}
if len(resp.Message) > 0 {
t.Fatalf("non-empty message %x in TALKRESP", resp.Message)
}
default:
t.Fatal("expected TALKRESP, got", resp.Name())
}
// Empty request ID.
resp = conn.reqresp(l1, &v5wire.TalkRequest{Protocol: "test-protocol"})
switch resp := resp.(type) {
case *v5wire.TalkResponse:
if len(resp.ReqID) > 0 {
t.Fatalf("wrong request ID %x in TALKRESP, want empty byte array", resp.ReqID)
}
if len(resp.Message) > 0 {
t.Fatalf("non-empty message %x in TALKRESP", resp.Message)
}
default:
t.Fatal("expected TALKRESP, got", resp.Name())
}
}
// This test checks that the remote node returns itself for FINDNODE with distance zero.
func (s *Suite) TestFindnodeZeroDistance(t *utesting.T) {
conn, l1 := s.listen1(t)
defer conn.close()
nodes, err := conn.findnode(l1, []uint{0})
if err != nil {
t.Fatal(err)
}
if len(nodes) != 1 {
t.Fatalf("remote returned more than one node for FINDNODE [0]")
}
if nodes[0].ID() != conn.remote.ID() {
t.Errorf("ID of response node is %v, want %v", nodes[0].ID(), conn.remote.ID())
}
}
// In this test, multiple nodes ping the node under test. After waiting for them to be
// accepted into the remote table, the test checks that they are returned by FINDNODE.
func (s *Suite) TestFindnodeResults(t *utesting.T) {
// Create bystanders.
nodes := make([]*bystander, 5)
added := make(chan enode.ID, len(nodes))
for i := range nodes {
nodes[i] = newBystander(t, s, added)
defer nodes[i].close()
}
// Get them added to the remote table.
timeout := 60 * time.Second
timeoutCh := time.After(timeout)
for count := 0; count < len(nodes); {
select {
case id := <-added:
t.Logf("bystander node %v added to remote table", id)
count++
case <-timeoutCh:
t.Errorf("remote added %d bystander nodes in %v, need %d to continue", count, timeout, len(nodes))
t.Logf("this can happen if the node has a non-empty table from previous runs")
return
}
}
t.Logf("all %d bystander nodes were added", len(nodes))
// Collect our nodes by distance.
var dists []uint
expect := make(map[enode.ID]*enode.Node)
for _, bn := range nodes {
n := bn.conn.localNode.Node()
expect[n.ID()] = n
d := uint(enode.LogDist(n.ID(), s.Dest.ID()))
if !containsUint(dists, d) {
dists = append(dists, d)
}
}
// Send FINDNODE for all distances.
conn, l1 := s.listen1(t)
defer conn.close()
foundNodes, err := conn.findnode(l1, dists)
if err != nil {
t.Fatal(err)
}
t.Logf("remote returned %d nodes for distance list %v", len(foundNodes), dists)
for _, n := range foundNodes {
delete(expect, n.ID())
}
if len(expect) > 0 {
t.Errorf("missing %d nodes in FINDNODE result", len(expect))
t.Logf("this can happen if the test is run multiple times in quick succession")
t.Logf("and the remote node hasn't removed dead nodes from previous runs yet")
} else {
t.Logf("all %d expected nodes were returned", len(nodes))
}
}
// A bystander is a node whose only purpose is filling a spot in the remote table.
type bystander struct {
dest *enode.Node
conn *conn
l net.PacketConn
addedCh chan enode.ID
done sync.WaitGroup
}
func newBystander(t *utesting.T, s *Suite, added chan enode.ID) *bystander {
conn, l := s.listen1(t)
conn.setEndpoint(l) // bystander nodes need IP/port to get pinged
bn := &bystander{
conn: conn,
l: l,
dest: s.Dest,
addedCh: added,
}
bn.done.Add(1)
go bn.loop()
return bn
}
// id returns the node ID of the bystander.
func (bn *bystander) id() enode.ID {
return bn.conn.localNode.ID()
}
// close shuts down loop.
func (bn *bystander) close() {
bn.conn.close()
bn.done.Wait()
}
// loop answers packets from the remote node until quit.
func (bn *bystander) loop() {
defer bn.done.Done()
var (
lastPing time.Time
wasAdded bool
)
for {
// Ping the remote node.
if !wasAdded && time.Since(lastPing) > 10*time.Second {
bn.conn.reqresp(bn.l, &v5wire.Ping{
ReqID: bn.conn.nextReqID(),
ENRSeq: bn.dest.Seq(),
})
lastPing = time.Now()
}
// Answer packets.
switch p := bn.conn.read(bn.l).(type) {
case *v5wire.Ping:
bn.conn.write(bn.l, &v5wire.Pong{
ReqID: p.ReqID,
ENRSeq: bn.conn.localNode.Seq(),
ToIP: bn.dest.IP(),
ToPort: uint16(bn.dest.UDP()),
}, nil)
wasAdded = true
bn.notifyAdded()
case *v5wire.Findnode:
bn.conn.write(bn.l, &v5wire.Nodes{ReqID: p.ReqID, Total: 1}, nil)
wasAdded = true
bn.notifyAdded()
case *v5wire.TalkRequest:
bn.conn.write(bn.l, &v5wire.TalkResponse{ReqID: p.ReqID}, nil)
case *readError:
if !netutil.IsTemporaryError(p.err) {
bn.conn.logf("shutting down: %v", p.err)
return
}
}
}
}
func (bn *bystander) notifyAdded() {
if bn.addedCh != nil {
bn.addedCh <- bn.id()
bn.addedCh = nil
}
}