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tailscale/wgengine/magicsock/magicsock_test.go

749 lines
18 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package magicsock
import (
"bytes"
crand "crypto/rand"
"crypto/tls"
"encoding/binary"
"fmt"
"net"
"net/http"
"net/http/httptest"
"os"
"strings"
"sync"
"testing"
"time"
"github.com/google/go-cmp/cmp"
"github.com/tailscale/wireguard-go/device"
"github.com/tailscale/wireguard-go/tun/tuntest"
"github.com/tailscale/wireguard-go/wgcfg"
"tailscale.com/derp"
"tailscale.com/derp/derphttp"
"tailscale.com/derp/derpmap"
"tailscale.com/stun"
"tailscale.com/types/key"
"tailscale.com/types/logger"
)
func TestListen(t *testing.T) {
epCh := make(chan string, 16)
epFunc := func(endpoints []string) {
for _, ep := range endpoints {
epCh <- ep
}
}
stunAddr, stunCleanupFn := serveSTUN(t)
defer stunCleanupFn()
port := pickPort(t)
conn, err := Listen(Options{
Port: port,
DERPs: derpmap.NewTestWorld(stunAddr),
EndpointsFunc: epFunc,
Logf: t.Logf,
})
if err != nil {
t.Fatal(err)
}
defer conn.Close()
go func() {
var pkt [64 << 10]byte
for {
_, _, _, err := conn.ReceiveIPv4(pkt[:])
if err != nil {
return
}
}
}()
timeout := time.After(10 * time.Second)
var endpoints []string
suffix := fmt.Sprintf(":%d", port)
collectEndpoints:
for {
select {
case ep := <-epCh:
endpoints = append(endpoints, ep)
if strings.HasSuffix(ep, suffix) {
break collectEndpoints
}
case <-timeout:
t.Fatalf("timeout with endpoints: %v", endpoints)
}
}
}
func pickPort(t *testing.T) uint16 {
t.Helper()
conn, err := net.ListenPacket("udp4", ":0")
if err != nil {
t.Fatal(err)
}
defer conn.Close()
return uint16(conn.LocalAddr().(*net.UDPAddr).Port)
}
func TestDerpIPConstant(t *testing.T) {
if DerpMagicIP != derpMagicIP.String() {
t.Errorf("str %q != IP %v", DerpMagicIP, derpMagicIP)
}
if len(derpMagicIP) != 4 {
t.Errorf("derpMagicIP is len %d; want 4", len(derpMagicIP))
}
}
func TestPickDERPFallback(t *testing.T) {
c := &Conn{
derps: derpmap.Prod(),
}
a := c.pickDERPFallback()
if a == 0 {
t.Fatalf("pickDERPFallback returned 0")
}
// Test that it's consistent.
for i := 0; i < 50; i++ {
b := c.pickDERPFallback()
if a != b {
t.Fatalf("got inconsistent %d vs %d values", a, b)
}
}
// Test that that the pointer value of c is blended in and
// distribution over nodes works.
got := map[int]int{}
for i := 0; i < 50; i++ {
c = &Conn{derps: derpmap.Prod()}
got[c.pickDERPFallback()]++
}
t.Logf("distribution: %v", got)
if len(got) < 2 {
t.Errorf("expected more than 1 node; got %v", got)
}
// Test that stickiness works.
const someNode = 123456
c.myDerp = someNode
if got := c.pickDERPFallback(); got != someNode {
t.Errorf("not sticky: got %v; want %v", got, someNode)
}
}
type stunStats struct {
mu sync.Mutex
readIPv4 int
readIPv6 int
}
func serveSTUN(t *testing.T) (addr string, cleanupFn func()) {
t.Helper()
// TODO(crawshaw): use stats to test re-STUN logic
var stats stunStats
pc, err := net.ListenPacket("udp4", ":3478")
if err != nil {
t.Fatalf("failed to open STUN listener: %v", err)
}
stunAddr := pc.LocalAddr().String()
stunAddr = strings.Replace(stunAddr, "0.0.0.0:", "127.0.0.1:", 1)
doneCh := make(chan struct{})
go runSTUN(t, pc, &stats, doneCh)
return stunAddr, func() {
pc.Close()
<-doneCh
}
}
func runSTUN(t *testing.T, pc net.PacketConn, stats *stunStats, done chan<- struct{}) {
defer close(done)
var buf [64 << 10]byte
for {
n, addr, err := pc.ReadFrom(buf[:])
if err != nil {
if strings.Contains(err.Error(), "closed network connection") {
t.Logf("STUN server shutdown")
return
}
continue
}
ua := addr.(*net.UDPAddr)
pkt := buf[:n]
if !stun.Is(pkt) {
continue
}
txid, err := stun.ParseBindingRequest(pkt)
if err != nil {
continue
}
stats.mu.Lock()
if ua.IP.To4() != nil {
stats.readIPv4++
} else {
stats.readIPv6++
}
stats.mu.Unlock()
res := stun.Response(txid, ua.IP, uint16(ua.Port))
if _, err := pc.WriteTo(res, addr); err != nil {
t.Logf("STUN server write failed: %v", err)
}
}
}
func makeConfigs(t *testing.T, ports []uint16) []wgcfg.Config {
t.Helper()
var privKeys []wgcfg.PrivateKey
var addresses [][]wgcfg.CIDR
for i := range ports {
privKey, err := wgcfg.NewPrivateKey()
if err != nil {
t.Fatal(err)
}
privKeys = append(privKeys, privKey)
addresses = append(addresses, []wgcfg.CIDR{
parseCIDR(t, fmt.Sprintf("1.0.0.%d/32", i+1)),
})
}
var cfgs []wgcfg.Config
for i, port := range ports {
cfg := wgcfg.Config{
Name: fmt.Sprintf("peer%d", i+1),
PrivateKey: privKeys[i],
Addresses: addresses[i],
ListenPort: port,
}
for peerNum, port := range ports {
if peerNum == i {
continue
}
peer := wgcfg.Peer{
PublicKey: privKeys[peerNum].Public(),
AllowedIPs: addresses[peerNum],
Endpoints: []wgcfg.Endpoint{{
Host: "127.0.0.1",
Port: port,
}},
PersistentKeepalive: 25,
}
cfg.Peers = append(cfg.Peers, peer)
}
cfgs = append(cfgs, cfg)
}
return cfgs
}
func parseCIDR(t *testing.T, addr string) wgcfg.CIDR {
t.Helper()
cidr, err := wgcfg.ParseCIDR(addr)
if err != nil {
t.Fatal(err)
}
return *cidr
}
func runDERP(t *testing.T) (s *derp.Server, addr string, cleanupFn func()) {
var serverPrivateKey key.Private
if _, err := crand.Read(serverPrivateKey[:]); err != nil {
t.Fatal(err)
}
s = derp.NewServer(serverPrivateKey, t.Logf)
httpsrv := httptest.NewUnstartedServer(derphttp.Handler(s))
httpsrv.Config.TLSNextProto = make(map[string]func(*http.Server, *tls.Conn, http.Handler))
httpsrv.StartTLS()
t.Logf("DERP server URL: %s", httpsrv.URL)
addr = strings.TrimPrefix(httpsrv.URL, "https://")
cleanupFn = func() {
httpsrv.CloseClientConnections()
httpsrv.Close()
s.Close()
}
return s, addr, cleanupFn
}
// devLogger returns a wireguard-go device.Logger that writes
// wireguard logs to the test logger.
func devLogger(t *testing.T, prefix string) *device.Logger {
pfx := []interface{}{prefix}
logf := func(format string, args ...interface{}) {
t.Helper()
t.Logf("%s: "+format, append(pfx, args...)...)
}
return &device.Logger{
Debug: logger.StdLogger(logf),
Info: logger.StdLogger(logf),
Error: logger.StdLogger(logf),
}
}
// TestDeviceStartStop exercises the startup and shutdown logic of
// wireguard-go, which is intimately intertwined with magicsock's own
// lifecycle. We seem to be good at generating deadlocks here, so if
// this test fails you should suspect a deadlock somewhere in startup
// or shutdown. It may be an infrequent flake, so run with
// -count=10000 to be sure.
func TestDeviceStartStop(t *testing.T) {
conn, err := Listen(Options{
EndpointsFunc: func(eps []string) {},
Logf: t.Logf,
})
if err != nil {
t.Fatal(err)
}
defer conn.Close()
tun := tuntest.NewChannelTUN()
dev := device.NewDevice(tun.TUN(), &device.DeviceOptions{
Logger: devLogger(t, "dev"),
CreateEndpoint: conn.CreateEndpoint,
CreateBind: conn.CreateBind,
SkipBindUpdate: true,
})
dev.Up()
dev.Close()
}
func TestTwoDevicePing(t *testing.T) {
// Wipe default DERP list, add local server.
// (Do it now, or derpHost will try to connect to derp1.tailscale.com.)
derpServer, derpAddr, derpCleanupFn := runDERP(t)
defer derpCleanupFn()
stunAddr, stunCleanupFn := serveSTUN(t)
defer stunCleanupFn()
derps := derpmap.NewTestWorldWith(&derpmap.Server{
ID: 1,
HostHTTPS: derpAddr,
STUN4: stunAddr,
Geo: "Testopolis",
})
epCh1 := make(chan []string, 16)
conn1, err := Listen(Options{
Logf: logger.WithPrefix(t.Logf, "conn1: "),
DERPs: derps,
EndpointsFunc: func(eps []string) {
epCh1 <- eps
},
derpTLSConfig: &tls.Config{InsecureSkipVerify: true},
})
if err != nil {
t.Fatal(err)
}
defer conn1.Close()
epCh2 := make(chan []string, 16)
conn2, err := Listen(Options{
Logf: logger.WithPrefix(t.Logf, "conn2: "),
DERPs: derps,
EndpointsFunc: func(eps []string) {
epCh2 <- eps
},
derpTLSConfig: &tls.Config{InsecureSkipVerify: true},
})
if err != nil {
t.Fatal(err)
}
defer conn2.Close()
ports := []uint16{conn1.LocalPort(), conn2.LocalPort()}
cfgs := makeConfigs(t, ports)
if err := conn1.SetPrivateKey(cfgs[0].PrivateKey); err != nil {
t.Fatal(err)
}
if err := conn2.SetPrivateKey(cfgs[1].PrivateKey); err != nil {
t.Fatal(err)
}
//uapi1, _ := cfgs[0].ToUAPI()
//t.Logf("cfg0: %v", uapi1)
//uapi2, _ := cfgs[1].ToUAPI()
//t.Logf("cfg1: %v", uapi2)
tun1 := tuntest.NewChannelTUN()
dev1 := device.NewDevice(tun1.TUN(), &device.DeviceOptions{
Logger: devLogger(t, "dev1"),
CreateEndpoint: conn1.CreateEndpoint,
CreateBind: conn1.CreateBind,
SkipBindUpdate: true,
})
dev1.Up()
if err := dev1.Reconfig(&cfgs[0]); err != nil {
t.Fatal(err)
}
defer dev1.Close()
tun2 := tuntest.NewChannelTUN()
dev2 := device.NewDevice(tun2.TUN(), &device.DeviceOptions{
Logger: devLogger(t, "dev2"),
CreateEndpoint: conn2.CreateEndpoint,
CreateBind: conn2.CreateBind,
SkipBindUpdate: true,
})
dev2.Up()
defer dev2.Close()
if err := dev2.Reconfig(&cfgs[1]); err != nil {
t.Fatal(err)
}
ping1 := func(t *testing.T) {
t.Helper()
msg2to1 := tuntest.Ping(net.ParseIP("1.0.0.1"), net.ParseIP("1.0.0.2"))
tun2.Outbound <- msg2to1
select {
case msgRecv := <-tun1.Inbound:
if !bytes.Equal(msg2to1, msgRecv) {
t.Error("ping did not transit correctly")
}
case <-time.After(3 * time.Second):
t.Error("ping did not transit")
}
}
ping2 := func(t *testing.T) {
t.Helper()
msg1to2 := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
tun1.Outbound <- msg1to2
select {
case msgRecv := <-tun2.Inbound:
if !bytes.Equal(msg1to2, msgRecv) {
t.Error("return ping did not transit correctly")
}
case <-time.After(3 * time.Second):
t.Error("return ping did not transit")
}
}
t.Run("ping 1.0.0.1", func(t *testing.T) { ping1(t) })
t.Run("ping 1.0.0.2", func(t *testing.T) { ping2(t) })
t.Run("ping 1.0.0.2 via SendPacket", func(t *testing.T) {
msg1to2 := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
if err := dev1.SendPacket(msg1to2); err != nil {
t.Fatal(err)
}
select {
case msgRecv := <-tun2.Inbound:
if !bytes.Equal(msg1to2, msgRecv) {
t.Error("return ping did not transit correctly")
}
case <-time.After(3 * time.Second):
t.Error("return ping did not transit")
}
})
t.Run("no-op dev1 reconfig", func(t *testing.T) {
if err := dev1.Reconfig(&cfgs[0]); err != nil {
t.Fatal(err)
}
ping1(t)
ping2(t)
})
if os.Getenv("RUN_CURSED_TESTS") == "" {
t.Skip("test is very broken, don't run in CI until it's reliable.")
}
pingSeq := func(t *testing.T, count int, totalTime time.Duration, strict bool) {
msg := func(i int) []byte {
b := tuntest.Ping(net.ParseIP("1.0.0.2"), net.ParseIP("1.0.0.1"))
b[len(b)-1] = byte(i) // set seq num
return b
}
// Space out ping transmissions so that the overall
// transmission happens in totalTime.
//
// We do this because the packet spray logic in magicsock is
// time-based to allow for reliable NAT traversal. However,
// for the packet spraying test further down, there needs to
// be at least 1 sprayed packet that is not the handshake, in
// case the handshake gets eaten by the race resolution logic.
//
// This is an inherent "race by design" in our current
// magicsock+wireguard-go codebase: sometimes, racing
// handshakes will result in a sub-optimal path for a few
// hundred milliseconds, until a subsequent spray corrects the
// issue. In order for the test to reflect that magicsock
// works as designed, we have to space out packet transmission
// here.
interPacketGap := totalTime / time.Duration(count)
if interPacketGap < 1*time.Millisecond {
interPacketGap = 0
}
for i := 0; i < count; i++ {
b := msg(i)
tun1.Outbound <- b
time.Sleep(interPacketGap)
}
for i := 0; i < count; i++ {
b := msg(i)
select {
case msgRecv := <-tun2.Inbound:
if !bytes.Equal(b, msgRecv) {
if strict {
t.Errorf("return ping %d did not transit correctly: %s", i, cmp.Diff(b, msgRecv))
}
}
case <-time.After(3 * time.Second):
if strict {
t.Errorf("return ping %d did not transit", i)
}
}
}
}
t.Run("ping 1.0.0.1 x50", func(t *testing.T) {
pingSeq(t, 50, 0, true)
})
// Add DERP relay.
derpEp := wgcfg.Endpoint{Host: "127.3.3.40", Port: 1}
ep0 := cfgs[0].Peers[0].Endpoints
ep0 = append([]wgcfg.Endpoint{derpEp}, ep0...)
cfgs[0].Peers[0].Endpoints = ep0
ep1 := cfgs[1].Peers[0].Endpoints
ep1 = append([]wgcfg.Endpoint{derpEp}, ep1...)
cfgs[1].Peers[0].Endpoints = ep1
if err := dev1.Reconfig(&cfgs[0]); err != nil {
t.Fatal(err)
}
if err := dev2.Reconfig(&cfgs[1]); err != nil {
t.Fatal(err)
}
t.Run("add DERP", func(t *testing.T) {
defer func() {
t.Logf("DERP vars: %s", derpServer.ExpVar().String())
}()
pingSeq(t, 20, 0, true)
})
// Disable real route.
cfgs[0].Peers[0].Endpoints = []wgcfg.Endpoint{derpEp}
cfgs[1].Peers[0].Endpoints = []wgcfg.Endpoint{derpEp}
if err := dev1.Reconfig(&cfgs[0]); err != nil {
t.Fatal(err)
}
if err := dev2.Reconfig(&cfgs[1]); err != nil {
t.Fatal(err)
}
time.Sleep(250 * time.Millisecond) // TODO remove
t.Run("all traffic over DERP", func(t *testing.T) {
defer func() {
t.Logf("DERP vars: %s", derpServer.ExpVar().String())
if t.Failed() || true {
uapi1, _ := cfgs[0].ToUAPI()
t.Logf("cfg0: %v", uapi1)
uapi2, _ := cfgs[1].ToUAPI()
t.Logf("cfg1: %v", uapi2)
}
}()
pingSeq(t, 20, 0, true)
})
dev1.RemoveAllPeers()
dev2.RemoveAllPeers()
// Give one peer a non-DERP endpoint. We expect the other to
// accept it via roamAddr.
cfgs[0].Peers[0].Endpoints = ep0
if ep2 := cfgs[1].Peers[0].Endpoints; len(ep2) != 1 {
t.Errorf("unexpected peer endpoints in dev2: %v", ep2)
}
if err := dev2.Reconfig(&cfgs[1]); err != nil {
t.Fatal(err)
}
if err := dev1.Reconfig(&cfgs[0]); err != nil {
t.Fatal(err)
}
// Dear future human debugging a test failure here: this test is
// flaky, and very infrequently will drop 1-2 of the 50 ping
// packets. This does not affect normal operation of tailscaled,
// but makes this test fail.
//
// TODO(danderson): finish root-causing and de-flake this test.
t.Run("one real route is enough thanks to spray", func(t *testing.T) {
pingSeq(t, 50, 700*time.Millisecond, false)
ep2 := dev2.Config().Peers[0].Endpoints
if len(ep2) != 2 {
t.Error("handshake spray failed to find real route")
}
})
}
// TestAddrSet tests AddrSet appendDests and UpdateDst.
func TestAddrSet(t *testing.T) {
mustUDPAddr := func(s string) *net.UDPAddr {
t.Helper()
ua, err := net.ResolveUDPAddr("udp", s)
if err != nil {
t.Fatal(err)
}
return ua
}
udpAddrs := func(ss ...string) (ret []net.UDPAddr) {
t.Helper()
for _, s := range ss {
ret = append(ret, *mustUDPAddr(s))
}
return ret
}
joinUDPs := func(in []*net.UDPAddr) string {
var sb strings.Builder
for i, ua := range in {
if i > 0 {
sb.WriteByte(',')
}
sb.WriteString(ua.String())
}
return sb.String()
}
var (
regPacket = []byte("some regular packet")
sprayPacket = []byte("0000")
)
binary.LittleEndian.PutUint32(sprayPacket[:4], device.MessageInitiationType)
if !shouldSprayPacket(sprayPacket) {
t.Fatal("sprayPacket should be classified as a spray packet for testing")
}
// A step is either a b+want appendDests tests, or an
// UpdateDst call, depending on which fields are set.
type step struct {
// advance is the time to advance the fake clock
// before the step.
advance time.Duration
// updateDst, if set, does an UpdateDst call and
// b+want are ignored.
updateDst *net.UDPAddr
b []byte
want string // comma-separated
}
tests := []struct {
name string
as *AddrSet
steps []step
}{
{
name: "reg_packet_no_curaddr",
as: &AddrSet{
addrs: udpAddrs("127.3.3.40:1", "123.45.67.89:123", "10.0.0.1:123"),
curAddr: -1, // unknown
roamAddr: nil,
},
steps: []step{
{b: regPacket, want: "127.3.3.40:1"},
},
},
{
name: "reg_packet_have_curaddr",
as: &AddrSet{
addrs: udpAddrs("127.3.3.40:1", "123.45.67.89:123", "10.0.0.1:123"),
curAddr: 1, // global IP
roamAddr: nil,
},
steps: []step{
{b: regPacket, want: "123.45.67.89:123"},
},
},
{
name: "reg_packet_have_roamaddr",
as: &AddrSet{
addrs: udpAddrs("127.3.3.40:1", "123.45.67.89:123", "10.0.0.1:123"),
curAddr: 2, // should be ignored
roamAddr: mustUDPAddr("5.6.7.8:123"),
},
steps: []step{
{b: regPacket, want: "5.6.7.8:123"},
{updateDst: mustUDPAddr("10.0.0.1:123")}, // no more roaming
{b: regPacket, want: "10.0.0.1:123"},
},
},
{
name: "start_roaming",
as: &AddrSet{
addrs: udpAddrs("127.3.3.40:1", "123.45.67.89:123", "10.0.0.1:123"),
curAddr: 2,
},
steps: []step{
{b: regPacket, want: "10.0.0.1:123"},
{updateDst: mustUDPAddr("4.5.6.7:123")},
{b: regPacket, want: "4.5.6.7:123"},
{updateDst: mustUDPAddr("5.6.7.8:123")},
{b: regPacket, want: "5.6.7.8:123"},
{updateDst: mustUDPAddr("123.45.67.89:123")}, // end roaming
{b: regPacket, want: "123.45.67.89:123"},
},
},
{
name: "spray_packet",
as: &AddrSet{
addrs: udpAddrs("127.3.3.40:1", "123.45.67.89:123", "10.0.0.1:123"),
curAddr: 2, // should be ignored
roamAddr: mustUDPAddr("5.6.7.8:123"),
},
steps: []step{
{b: sprayPacket, want: "127.3.3.40:1,123.45.67.89:123,10.0.0.1:123,5.6.7.8:123"},
{advance: 300 * time.Millisecond, b: regPacket, want: "127.3.3.40:1,123.45.67.89:123,10.0.0.1:123,5.6.7.8:123"},
{advance: 300 * time.Millisecond, b: regPacket, want: "127.3.3.40:1,123.45.67.89:123,10.0.0.1:123,5.6.7.8:123"},
{advance: 3, b: regPacket, want: "5.6.7.8:123"},
{advance: 2 * time.Millisecond, updateDst: mustUDPAddr("10.0.0.1:123")},
{advance: 3, b: regPacket, want: "10.0.0.1:123"},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
faket := time.Unix(0, 0)
tt.as.Logf = t.Logf
tt.as.clock = func() time.Time { return faket }
for i, st := range tt.steps {
faket = faket.Add(st.advance)
if st.updateDst != nil {
if err := tt.as.UpdateDst(st.updateDst); err != nil {
t.Fatal(err)
}
continue
}
got, _ := tt.as.appendDests(nil, st.b)
if gotStr := joinUDPs(got); gotStr != st.want {
t.Errorf("step %d: got %v; want %v", i, gotStr, st.want)
}
}
})
}
}