Files
tailscale/net/netmon/netmon_test.go
T
Jonathan Nobels 643e91f2eb net/netmon: move TailscaleInterfaceIndex out of netmon.State (#18428)
fixes tailscale/tailscale#18418

Both Serve and PeerAPI broke when we moved the TailscaleInterfaceName
into State, which is updated asynchronously and may not be
available when we configure the listeners.

This extracts the explicit interface name property from netmon.State
and adds as a static struct with getters that have proper error
handling.

The bug is only found in sandboxed Darwin clients, where we
need to know the Tailscale interface details in order to set up the
listeners correctly (they must bind to our interface explicitly to escape
the network sandboxing that is applied by NECP).

Currently set only sandboxed macOS and Plan9 set this but it will
also be useful on Windows to simplify interface filtering in netns.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
2026-01-16 14:53:23 -05:00

654 lines
15 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package netmon
import (
"flag"
"net"
"net/netip"
"reflect"
"strings"
"sync/atomic"
"testing"
"time"
"tailscale.com/util/eventbus"
"tailscale.com/util/eventbus/eventbustest"
"tailscale.com/util/mak"
)
func TestMonitorStartClose(t *testing.T) {
bus := eventbus.New()
defer bus.Close()
mon, err := New(bus, t.Logf)
if err != nil {
t.Fatal(err)
}
mon.Start()
if err := mon.Close(); err != nil {
t.Fatal(err)
}
}
func TestMonitorJustClose(t *testing.T) {
bus := eventbus.New()
defer bus.Close()
mon, err := New(bus, t.Logf)
if err != nil {
t.Fatal(err)
}
if err := mon.Close(); err != nil {
t.Fatal(err)
}
}
func TestMonitorInjectEvent(t *testing.T) {
bus := eventbus.New()
defer bus.Close()
mon, err := New(bus, t.Logf)
if err != nil {
t.Fatal(err)
}
defer mon.Close()
got := make(chan bool, 1)
mon.RegisterChangeCallback(func(*ChangeDelta) {
select {
case got <- true:
default:
}
})
mon.Start()
mon.InjectEvent()
select {
case <-got:
// Pass.
case <-time.After(5 * time.Second):
t.Fatal("timeout waiting for callback")
}
}
func TestMonitorInjectEventOnBus(t *testing.T) {
bus := eventbustest.NewBus(t)
mon, err := New(bus, t.Logf)
if err != nil {
t.Fatal(err)
}
defer mon.Close()
tw := eventbustest.NewWatcher(t, bus)
mon.Start()
mon.InjectEvent()
if err := eventbustest.Expect(tw, eventbustest.Type[ChangeDelta]()); err != nil {
t.Error(err)
}
}
var (
monitor = flag.String("monitor", "", `go into monitor mode like 'route monitor'; test never terminates. Value can be either "raw" or "callback"`)
monitorDuration = flag.Duration("monitor-duration", 0, "if non-zero, how long to run TestMonitorMode. Zero means forever.")
)
func TestMonitorMode(t *testing.T) {
switch *monitor {
case "":
t.Skip("skipping non-test without --monitor")
case "raw", "callback", "eventbus":
default:
t.Skipf(`invalid --monitor value: must be "raw", "callback" or "eventbus"`)
}
bus := eventbustest.NewBus(t)
tw := eventbustest.NewWatcher(t, bus)
mon, err := New(bus, t.Logf)
if err != nil {
t.Fatal(err)
}
switch *monitor {
case "raw":
var closed atomic.Bool
if *monitorDuration != 0 {
t := time.AfterFunc(*monitorDuration, func() {
closed.Store(true)
mon.Close()
})
defer t.Stop()
}
for {
msg, err := mon.om.Receive()
if closed.Load() {
return
}
if err != nil {
t.Fatal(err)
}
t.Logf("msg: %#v", msg)
}
case "callback":
var done <-chan time.Time
if *monitorDuration != 0 {
t := time.NewTimer(*monitorDuration)
defer t.Stop()
done = t.C
}
n := 0
mon.RegisterChangeCallback(func(d *ChangeDelta) {
n++
t.Logf("cb: changed=%v, ifSt=%v", d.RebindLikelyRequired, d.CurrentState())
})
mon.Start()
<-done
t.Logf("%v callbacks", n)
case "eventbus":
time.AfterFunc(*monitorDuration, bus.Close)
n := 0
mon.Start()
eventbustest.Expect(tw, func(event *ChangeDelta) (bool, error) {
n++
t.Logf("cb: changed=%v, ifSt=%v", event.RebindLikelyRequired, event.CurrentState())
return false, nil // Return false, indicating we wanna look for more events
})
t.Logf("%v events", n)
}
}
// tests (*ChangeDelta).RebindRequired
func TestRebindRequired(t *testing.T) {
// s1 must not be nil by definition
tests := []struct {
name string
s1, s2 *State
tsIfName string
want bool
}{
{
name: "nil_mix",
s2: new(State),
want: true,
},
{
name: "eq",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
want: false,
},
{
name: "new-with-no-addr",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
"bar": {},
},
},
want: false,
},
{
name: "ignore-tailscale-interface-appearing",
tsIfName: "tailscale0",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
"tailscale0": {netip.MustParsePrefix("100.69.4.20/32")},
},
},
want: false,
},
{
name: "ignore-tailscale-interface-disappearing",
tsIfName: "tailscale0",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
"tailscale0": {netip.MustParsePrefix("100.69.4.20/32")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
want: false,
},
{
name: "new-with-multicast-addr",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
"bar": {netip.MustParsePrefix("224.0.0.1/32")},
},
},
want: false,
},
{
name: "old-with-addr-dropped",
s1: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
"bar": {netip.MustParsePrefix("192.168.0.1/32")},
},
},
s2: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"bar": {netip.MustParsePrefix("192.168.0.1/32")},
},
},
want: true,
},
{
name: "old-with-no-addr-dropped",
s1: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {},
"bar": {netip.MustParsePrefix("192.168.0.1/16")},
},
},
s2: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"bar": {netip.MustParsePrefix("192.168.0.1/16")},
},
},
want: false,
},
{
name: "default-route-changed",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
want: true,
},
{
name: "some-interesting-ip-changed",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.3/16")},
},
},
want: true,
},
{
// (barnstar) TODO: ULA addresses are only useful in some contexts,
// so maybe this shouldn't trigger rebinds after all? Needs more thought.
name: "ipv6-ula-addressed-appeared",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {
netip.MustParsePrefix("10.0.1.2/16"),
netip.MustParsePrefix("fd15:bbfa:c583:4fce:f4fb:4ff:fe1a:4148/64"),
},
},
},
want: true,
},
{
// (barnstar) TODO: ULA addresses are only useful in some contexts,
// so maybe this shouldn't trigger rebinds after all? Needs more thought.
name: "ipv6-ula-addressed-disappeared",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {
netip.MustParsePrefix("10.0.1.2/16"),
netip.MustParsePrefix("fd15:bbfa:c583:4fce:f4fb:4ff:fe1a:4148/64"),
},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
want: true,
},
{
name: "ipv6-link-local-addressed-appeared",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {netip.MustParsePrefix("10.0.1.2/16")},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {
netip.MustParsePrefix("10.0.1.2/16"),
netip.MustParsePrefix("fe80::f242:25ff:fe64:b280/64"),
},
},
},
want: false,
},
{
name: "ipv6-addressed-changed",
s1: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {
netip.MustParsePrefix("10.0.1.2/16"),
netip.MustParsePrefix("2001::f242:25ff:fe64:b280/64"),
netip.MustParsePrefix("fe80::f242:25ff:fe64:b280/64"),
},
},
},
s2: &State{
DefaultRouteInterface: "foo",
InterfaceIPs: map[string][]netip.Prefix{
"foo": {
netip.MustParsePrefix("10.0.1.2/16"),
netip.MustParsePrefix("2001::beef:8bad:f00d:b280/64"),
netip.MustParsePrefix("fe80::f242:25ff:fe64:b280/64"),
},
},
},
want: true,
},
{
name: "have-addr-changed",
s1: &State{
HaveV6: false,
HaveV4: false,
},
s2: &State{
HaveV6: true,
HaveV4: true,
},
want: true,
},
{
name: "have-addr-unchanged",
s1: &State{
HaveV6: true,
HaveV4: true,
},
s2: &State{
HaveV6: true,
HaveV4: true,
},
want: false,
},
{
name: "new-is-less-expensive",
s1: &State{
IsExpensive: true,
},
s2: &State{
IsExpensive: false,
},
want: true,
},
{
name: "new-is-more-expensive",
s1: &State{
IsExpensive: false,
},
s2: &State{
IsExpensive: true,
},
want: false,
},
{
name: "uninteresting-interface-added",
s1: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"bar": {netip.MustParsePrefix("192.168.0.1/16")},
},
},
s2: &State{
DefaultRouteInterface: "bar",
InterfaceIPs: map[string][]netip.Prefix{
"bar": {netip.MustParsePrefix("192.168.0.1/16")},
"boring": {netip.MustParsePrefix("fd7a:115c:a1e0:ab12:4843:cd96:625e:13ce/64")},
},
},
want: false,
},
}
withIsInterestingInterface(t, func(ni Interface, pfxs []netip.Prefix) bool {
return !strings.HasPrefix(ni.Name, "boring")
})
saveAndRestoreTailscaleIfaceProps(t)
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
// Populate dummy interfaces where missing.
for _, s := range []*State{tt.s1, tt.s2} {
if s == nil {
continue
}
for name := range s.InterfaceIPs {
if _, ok := s.Interface[name]; !ok {
mak.Set(&s.Interface, name, Interface{Interface: &net.Interface{
Name: name,
}})
}
}
}
SetTailscaleInterfaceProps(tt.tsIfName, 1)
cd, err := NewChangeDelta(tt.s1, tt.s2, false, true)
if err != nil {
t.Fatalf("NewChangeDelta error: %v", err)
}
_ = cd // in case we need it later
if got := cd.RebindLikelyRequired; got != tt.want {
t.Errorf("RebindRequired = %v; want %v", got, tt.want)
}
})
}
}
func saveAndRestoreTailscaleIfaceProps(t *testing.T) {
t.Helper()
index, _ := TailscaleInterfaceIndex()
name, _ := TailscaleInterfaceName()
t.Cleanup(func() {
SetTailscaleInterfaceProps(name, index)
})
}
func withIsInterestingInterface(t *testing.T, fn func(Interface, []netip.Prefix) bool) {
t.Helper()
old := IsInterestingInterface
IsInterestingInterface = fn
t.Cleanup(func() { IsInterestingInterface = old })
}
func TestIncludesRoutableIP(t *testing.T) {
routable := []netip.Prefix{
netip.MustParsePrefix("1.2.3.4/32"),
netip.MustParsePrefix("10.0.0.1/24"), // RFC1918 IPv4 (private)
netip.MustParsePrefix("172.16.0.1/12"), // RFC1918 IPv4 (private)
netip.MustParsePrefix("192.168.1.1/24"), // RFC1918 IPv4 (private)
netip.MustParsePrefix("fd15:dead:beef::1/64"), // IPv6 ULA
netip.MustParsePrefix("2001:db8::1/64"), // global IPv6
}
nonRoutable := []netip.Prefix{
netip.MustParsePrefix("ff00::/8"), // multicast IPv6 (should be filtered)
netip.MustParsePrefix("fe80::1/64"), // link-local IPv6
netip.MustParsePrefix("::1/128"), // loopback IPv6
netip.MustParsePrefix("::/128"), // unspecified IPv6
netip.MustParsePrefix("224.0.0.1/32"), // multicast IPv4
netip.MustParsePrefix("127.0.0.1/32"), // loopback IPv4
}
got, want := filterRoutableIPs(
append(nonRoutable, routable...),
), routable
if !reflect.DeepEqual(got, want) {
t.Fatalf("filterRoutableIPs returned %v; want %v", got, want)
}
}
func TestPrefixesEqual(t *testing.T) {
tests := []struct {
name string
a, b []netip.Prefix
want bool
}{
{
name: "empty",
a: []netip.Prefix{},
b: []netip.Prefix{},
want: true,
},
{
name: "single-equal",
a: []netip.Prefix{netip.MustParsePrefix("10.0.0.1/24")},
b: []netip.Prefix{netip.MustParsePrefix("10.0.0.1/24")},
want: true,
},
{
name: "single-different",
a: []netip.Prefix{netip.MustParsePrefix("10.0.0.1/24")},
b: []netip.Prefix{netip.MustParsePrefix("10.0.0.2/24")},
want: false,
},
{
name: "unordered-equal",
a: []netip.Prefix{
netip.MustParsePrefix("10.0.0.1/24"),
netip.MustParsePrefix("10.0.2.1/24"),
},
b: []netip.Prefix{
netip.MustParsePrefix("10.0.2.1/24"),
netip.MustParsePrefix("10.0.0.1/24"),
},
want: true,
},
{
name: "subset",
a: []netip.Prefix{
netip.MustParsePrefix("10.0.2.1/24"),
},
b: []netip.Prefix{
netip.MustParsePrefix("10.0.2.1/24"),
netip.MustParsePrefix("10.0.0.1/24"),
},
want: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := prefixesEqual(tt.a, tt.b)
if got != tt.want {
t.Errorf("prefixesEqual(%v, %v) = %v; want %v", tt.a, tt.b, got, tt.want)
}
})
}
}
func TestForeachInterface(t *testing.T) {
tests := []struct {
name string
addrs []net.Addr
want []string
}{
{
name: "Mixed_IPv4_and_IPv6",
addrs: []net.Addr{
&net.IPNet{IP: net.IPv4(1, 2, 3, 4), Mask: net.CIDRMask(24, 32)},
&net.IPAddr{IP: net.IP{5, 6, 7, 8}, Zone: ""},
&net.IPNet{IP: net.ParseIP("2001:db8::1"), Mask: net.CIDRMask(64, 128)},
&net.IPAddr{IP: net.ParseIP("2001:db8::2"), Zone: ""},
},
want: []string{"1.2.3.4", "5.6.7.8", "2001:db8::1", "2001:db8::2"},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
var got []string
ifaces := InterfaceList{
{
Interface: &net.Interface{Name: "eth0"},
AltAddrs: tt.addrs,
},
}
ifaces.ForeachInterface(func(iface Interface, prefixes []netip.Prefix) {
for _, prefix := range prefixes {
ip := prefix.Addr()
got = append(got, ip.String())
}
})
if !reflect.DeepEqual(got, tt.want) {
t.Errorf("got %q, want %q", got, tt.want)
}
})
}
}