wireguard-go/device/device_test.go
Josh Bleecher Snyder af408eb940 device: print direction when ping transit fails
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-08 12:01:08 -08:00

426 lines
10 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2021 WireGuard LLC. All Rights Reserved.
*/
package device
import (
"bytes"
"encoding/hex"
"fmt"
"io/ioutil"
"math/rand"
"net"
"runtime"
"runtime/pprof"
"sync"
"sync/atomic"
"testing"
"time"
"golang.zx2c4.com/wireguard/tun/tuntest"
)
func getFreePort(tb testing.TB) string {
l, err := net.ListenPacket("udp", "localhost:0")
if err != nil {
tb.Fatal(err)
}
defer l.Close()
return fmt.Sprintf("%d", l.LocalAddr().(*net.UDPAddr).Port)
}
// uapiCfg returns a string that contains cfg formatted use with IpcSet.
// cfg is a series of alternating key/value strings.
// uapiCfg exists because editors and humans like to insert
// whitespace into configs, which can cause failures, some of which are silent.
// For example, a leading blank newline causes the remainder
// of the config to be silently ignored.
func uapiCfg(cfg ...string) string {
if len(cfg)%2 != 0 {
panic("odd number of args to uapiReader")
}
buf := new(bytes.Buffer)
for i, s := range cfg {
buf.WriteString(s)
sep := byte('\n')
if i%2 == 0 {
sep = '='
}
buf.WriteByte(sep)
}
return buf.String()
}
// genConfigs generates a pair of configs that connect to each other.
// The configs use distinct, probably-usable ports.
func genConfigs(tb testing.TB) (cfgs [2]string) {
var port1, port2 string
for port1 == port2 {
port1 = getFreePort(tb)
port2 = getFreePort(tb)
}
cfgs[0] = uapiCfg(
"private_key", "481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58",
"listen_port", port1,
"replace_peers", "true",
"public_key", "f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725",
"protocol_version", "1",
"replace_allowed_ips", "true",
"allowed_ip", "1.0.0.2/32",
"endpoint", "127.0.0.1:"+port2,
)
cfgs[1] = uapiCfg(
"private_key", "98c7989b1661a0d64fd6af3502000f87716b7c4bbcf00d04fc6073aa7b539768",
"listen_port", port2,
"replace_peers", "true",
"public_key", "49e80929259cebdda4f322d6d2b1a6fad819d603acd26fd5d845e7a123036427",
"protocol_version", "1",
"replace_allowed_ips", "true",
"allowed_ip", "1.0.0.1/32",
"endpoint", "127.0.0.1:"+port1,
)
return
}
// A testPair is a pair of testPeers.
type testPair [2]testPeer
// A testPeer is a peer used for testing.
type testPeer struct {
tun *tuntest.ChannelTUN
dev *Device
ip net.IP
}
type SendDirection bool
const (
Ping SendDirection = true
Pong SendDirection = false
)
func (d SendDirection) String() string {
if d == Ping {
return "ping"
}
return "pong"
}
func (pair *testPair) Send(tb testing.TB, ping SendDirection, done chan struct{}) {
tb.Helper()
p0, p1 := pair[0], pair[1]
if !ping {
// pong is the new ping
p0, p1 = p1, p0
}
msg := tuntest.Ping(p0.ip, p1.ip)
p1.tun.Outbound <- msg
timer := time.NewTimer(5 * time.Second)
defer timer.Stop()
var err error
select {
case msgRecv := <-p0.tun.Inbound:
if !bytes.Equal(msg, msgRecv) {
err = fmt.Errorf("%s did not transit correctly", ping)
}
case <-timer.C:
err = fmt.Errorf("%s did not transit", ping)
case <-done:
}
if err != nil {
// The error may have occurred because the test is done.
select {
case <-done:
return
default:
}
// Real error.
tb.Error(err)
}
}
// genTestPair creates a testPair.
func genTestPair(tb testing.TB) (pair testPair) {
const maxAttempts = 10
NextAttempt:
for i := 0; i < maxAttempts; i++ {
cfg := genConfigs(tb)
// Bring up a ChannelTun for each config.
for i := range pair {
p := &pair[i]
p.tun = tuntest.NewChannelTUN()
if i == 0 {
p.ip = net.ParseIP("1.0.0.1")
} else {
p.ip = net.ParseIP("1.0.0.2")
}
level := LogLevelVerbose
if _, ok := tb.(*testing.B); ok && !testing.Verbose() {
level = LogLevelError
}
p.dev = NewDevice(p.tun.TUN(), NewLogger(level, fmt.Sprintf("dev%d: ", i)))
p.dev.Up()
if err := p.dev.IpcSet(cfg[i]); err != nil {
// genConfigs attempted to pick ports that were free.
// There's a tiny window between genConfigs closing the port
// and us opening it, during which another process could
// start using it. We probably just lost that race.
// Try again from the beginning.
// If there's something permanent wrong,
// we'll see that when we run out of attempts.
tb.Logf("failed to configure device %d: %v", i, err)
p.dev.Close()
continue NextAttempt
}
// The device might still not be up, e.g. due to an error
// in RoutineTUNEventReader's call to dev.Up that got swallowed.
// Assume it's due to a transient error (port in use), and retry.
if !p.dev.isUp() {
tb.Logf("device %d did not come up, trying again", i)
p.dev.Close()
continue NextAttempt
}
// The device is up. Close it when the test completes.
tb.Cleanup(p.dev.Close)
}
return // success
}
tb.Fatalf("genChannelTUNs: failed %d times", maxAttempts)
return
}
func TestTwoDevicePing(t *testing.T) {
goroutineLeakCheck(t)
pair := genTestPair(t)
t.Run("ping 1.0.0.1", func(t *testing.T) {
pair.Send(t, Ping, nil)
})
t.Run("ping 1.0.0.2", func(t *testing.T) {
pair.Send(t, Pong, nil)
})
}
func TestUpDown(t *testing.T) {
goroutineLeakCheck(t)
const itrials = 200
const otrials = 10
for n := 0; n < otrials; n++ {
pair := genTestPair(t)
for i := range pair {
for k := range pair[i].dev.peers.keyMap {
pair[i].dev.IpcSet(fmt.Sprintf("public_key=%s\npersistent_keepalive_interval=1\n", hex.EncodeToString(k[:])))
}
}
var wg sync.WaitGroup
wg.Add(len(pair))
for i := range pair {
go func(d *Device) {
defer wg.Done()
for i := 0; i < itrials; i++ {
d.Up()
time.Sleep(time.Duration(rand.Intn(int(time.Nanosecond * (0x10000 - 1)))))
d.Down()
time.Sleep(time.Duration(rand.Intn(int(time.Nanosecond * (0x10000 - 1)))))
}
}(pair[i].dev)
}
wg.Wait()
for i := range pair {
pair[i].dev.Up()
pair[i].dev.Close()
}
}
}
// TestConcurrencySafety does other things concurrently with tunnel use.
// It is intended to be used with the race detector to catch data races.
func TestConcurrencySafety(t *testing.T) {
pair := genTestPair(t)
done := make(chan struct{})
const warmupIters = 10
var warmup sync.WaitGroup
warmup.Add(warmupIters)
go func() {
// Send data continuously back and forth until we're done.
// Note that we may continue to attempt to send data
// even after done is closed.
i := warmupIters
for ping := Ping; ; ping = !ping {
pair.Send(t, ping, done)
select {
case <-done:
return
default:
}
if i > 0 {
warmup.Done()
i--
}
}
}()
warmup.Wait()
applyCfg := func(cfg string) {
err := pair[0].dev.IpcSet(cfg)
if err != nil {
t.Fatal(err)
}
}
// Change persistent_keepalive_interval concurrently with tunnel use.
t.Run("persistentKeepaliveInterval", func(t *testing.T) {
cfg := uapiCfg(
"public_key", "f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725",
"persistent_keepalive_interval", "1",
)
for i := 0; i < 1000; i++ {
applyCfg(cfg)
}
})
// Change private keys concurrently with tunnel use.
t.Run("privateKey", func(t *testing.T) {
bad := uapiCfg("private_key", "7777777777777777777777777777777777777777777777777777777777777777")
good := uapiCfg("private_key", "481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58")
// Set iters to a large number like 1000 to flush out data races quickly.
// Don't leave it large. That can cause logical races
// in which the handshake is interleaved with key changes
// such that the private key appears to be unchanging but
// other state gets reset, which can cause handshake failures like
// "Received packet with invalid mac1".
const iters = 1
for i := 0; i < iters; i++ {
applyCfg(bad)
applyCfg(good)
}
})
close(done)
}
func assertNil(t *testing.T, err error) {
if err != nil {
t.Fatal(err)
}
}
func assertEqual(t *testing.T, a, b []byte) {
if !bytes.Equal(a, b) {
t.Fatal(a, "!=", b)
}
}
func randDevice(t *testing.T) *Device {
sk, err := newPrivateKey()
if err != nil {
t.Fatal(err)
}
tun := newDummyTUN("dummy")
logger := NewLogger(LogLevelError, "")
device := NewDevice(tun, logger)
device.SetPrivateKey(sk)
return device
}
func BenchmarkLatency(b *testing.B) {
pair := genTestPair(b)
// Establish a connection.
pair.Send(b, Ping, nil)
pair.Send(b, Pong, nil)
b.ResetTimer()
for i := 0; i < b.N; i++ {
pair.Send(b, Ping, nil)
pair.Send(b, Pong, nil)
}
}
func BenchmarkThroughput(b *testing.B) {
pair := genTestPair(b)
// Establish a connection.
pair.Send(b, Ping, nil)
pair.Send(b, Pong, nil)
// Measure how long it takes to receive b.N packets,
// starting when we receive the first packet.
var recv uint64
var elapsed time.Duration
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
var start time.Time
for {
<-pair[0].tun.Inbound
new := atomic.AddUint64(&recv, 1)
if new == 1 {
start = time.Now()
}
// Careful! Don't change this to else if; b.N can be equal to 1.
if new == uint64(b.N) {
elapsed = time.Since(start)
return
}
}
}()
// Send packets as fast as we can until we've received enough.
ping := tuntest.Ping(pair[0].ip, pair[1].ip)
pingc := pair[1].tun.Outbound
var sent uint64
for atomic.LoadUint64(&recv) != uint64(b.N) {
sent++
pingc <- ping
}
wg.Wait()
b.ReportMetric(float64(elapsed)/float64(b.N), "ns/op")
b.ReportMetric(1-float64(b.N)/float64(sent), "packet-loss")
}
func BenchmarkUAPIGet(b *testing.B) {
pair := genTestPair(b)
pair.Send(b, Ping, nil)
pair.Send(b, Pong, nil)
b.ReportAllocs()
b.ResetTimer()
for i := 0; i < b.N; i++ {
pair[0].dev.IpcGetOperation(ioutil.Discard)
}
}
func goroutineLeakCheck(t *testing.T) {
goroutines := func() (int, []byte) {
p := pprof.Lookup("goroutine")
b := new(bytes.Buffer)
p.WriteTo(b, 1)
return p.Count(), b.Bytes()
}
startGoroutines, startStacks := goroutines()
t.Cleanup(func() {
if t.Failed() {
return
}
// Give goroutines time to exit, if they need it.
for i := 0; i < 10000; i++ {
if runtime.NumGoroutine() <= startGoroutines {
return
}
time.Sleep(1 * time.Millisecond)
}
endGoroutines, endStacks := goroutines()
t.Logf("starting stacks:\n%s\n", startStacks)
t.Logf("ending stacks:\n%s\n", endStacks)
t.Fatalf("expected %d goroutines, got %d, leak?", startGoroutines, endGoroutines)
})
}