wireguard-go/device/device_test.go
Josh Bleecher Snyder 63066ce406 device: fix persistent_keepalive_interval data races
Co-authored-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00

259 lines
6.3 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
*/
package device
import (
"bytes"
"errors"
"fmt"
"io"
"net"
"sync"
"testing"
"time"
"golang.zx2c4.com/wireguard/tun/tuntest"
)
func getFreePort(t *testing.T) string {
l, err := net.ListenPacket("udp", "localhost:0")
if err != nil {
t.Fatal(err)
}
defer l.Close()
return fmt.Sprintf("%d", l.LocalAddr().(*net.UDPAddr).Port)
}
// uapiCfg returns a reader that contains cfg formatted use with IpcSetOperation.
// 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) io.ReadSeeker {
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 bytes.NewReader(buf.Bytes())
}
// genConfigs generates a pair of configs that connect to each other.
// The configs use distinct, probably-usable ports.
func genConfigs(t *testing.T) (cfgs [2]io.Reader) {
var port1, port2 string
for port1 == port2 {
port1 = getFreePort(t)
port2 = getFreePort(t)
}
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 (pair *testPair) Send(t *testing.T, ping SendDirection, done chan struct{}) {
t.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 = errors.New("ping did not transit correctly")
}
case <-timer.C:
err = errors.New("ping did not transit")
case <-done:
}
if err != nil {
// The error may have occurred because the test is done.
select {
case <-done:
return
default:
}
// Real error.
t.Error(err)
}
}
// genTestPair creates a testPair.
func genTestPair(t *testing.T) (pair testPair) {
const maxAttempts = 10
NextAttempt:
for i := 0; i < maxAttempts; i++ {
cfg := genConfigs(t)
// 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")
}
p.dev = NewDevice(p.tun.TUN(), NewLogger(LogLevelDebug, fmt.Sprintf("dev%d: ", i)))
p.dev.Up()
if err := p.dev.IpcSetOperation(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.
t.Logf("failed to configure device %d: %v", i, err)
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.Get() {
t.Logf("device %d did not come up, trying again", i)
continue NextAttempt
}
// The device is up. Close it when the test completes.
t.Cleanup(p.dev.Close)
}
return // success
}
t.Fatalf("genChannelTUNs: failed %d times", maxAttempts)
return
}
func TestTwoDevicePing(t *testing.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)
})
}
// 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()
// 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++ {
cfg.Seek(0, io.SeekStart)
err := pair[0].dev.IpcSetOperation(cfg)
if err != nil {
t.Fatal(err)
}
}
})
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
}