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net/{interfaces,netmon}: remove "interesting", EqualFiltered API

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This removes a lot of API from net/interfaces (including all the
filter types, EqualFiltered, active Tailscale interface func, etc) and
moves the "major" change detection to net/netmon which knows more
about the world and the previous/new states.

Updates #9040

Change-Id: I7fe66a23039c6347ae5458745b709e7ebdcce245
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2023-08-23 11:48:05 -07:00 committed by Brad Fitzpatrick
parent 6dfa403e6b
commit 11ece02f52
7 changed files with 476 additions and 196 deletions
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21
net/dns/nm.go
View File

@ -8,13 +8,14 @@
import (
"context"
"fmt"
"net"
"net/netip"
"sort"
"time"
"github.com/godbus/dbus/v5"
"github.com/josharian/native"
"tailscale.com/net/interfaces"
"tailscale.com/net/tsaddr"
"tailscale.com/util/dnsname"
)
@ -139,14 +140,18 @@ func (m *nmManager) trySet(ctx context.Context, config OSConfig) error {
// tell it explicitly to keep it. Read out the current interface
// settings and mirror them out to NetworkManager.
var addrs6 []map[string]any
addrs, _, err := interfaces.Tailscale()
if err == nil {
if tsIf, err := net.InterfaceByName(m.interfaceName); err == nil {
addrs, _ := tsIf.Addrs()
for _, a := range addrs {
if a.Is6() {
addrs6 = append(addrs6, map[string]any{
"address": a.String(),
"prefix": uint32(128),
})
if ipnet, ok := a.(*net.IPNet); ok {
nip, ok := netip.AddrFromSlice(ipnet.IP)
nip = nip.Unmap()
if ok && tsaddr.IsTailscaleIP(nip) && nip.Is6() {
addrs6 = append(addrs6, map[string]any{
"address": nip.String(),
"prefix": uint32(128),
})
}
}
}
}

218
net/interfaces/interfaces.go
View File

@ -11,6 +11,7 @@
"net/http"
"net/netip"
"runtime"
"slices"
"sort"
"strings"
@ -24,49 +25,6 @@
// which HTTP proxy the system should use.
var LoginEndpointForProxyDetermination = "https://controlplane.tailscale.com/"
// Tailscale returns the current machine's Tailscale interface, if any.
// If none is found, all zero values are returned.
// A non-nil error is only returned on a problem listing the system interfaces.
func Tailscale() ([]netip.Addr, *net.Interface, error) {
ifs, err := netInterfaces()
if err != nil {
return nil, nil, err
}
for _, iface := range ifs {
if !maybeTailscaleInterfaceName(iface.Name) {
continue
}
addrs, err := iface.Addrs()
if err != nil {
continue
}
var tsIPs []netip.Addr
for _, a := range addrs {
if ipnet, ok := a.(*net.IPNet); ok {
nip, ok := netip.AddrFromSlice(ipnet.IP)
nip = nip.Unmap()
if ok && tsaddr.IsTailscaleIP(nip) {
tsIPs = append(tsIPs, nip)
}
}
}
if len(tsIPs) > 0 {
return tsIPs, iface.Interface, nil
}
}
return nil, nil, nil
}
// maybeTailscaleInterfaceName reports whether s is an interface
// name that might be used by Tailscale.
func maybeTailscaleInterfaceName(s string) bool {
return s == "Tailscale" ||
strings.HasPrefix(s, "wg") ||
strings.HasPrefix(s, "ts") ||
strings.HasPrefix(s, "tailscale") ||
strings.HasPrefix(s, "utun")
}
func isUp(nif *net.Interface) bool { return nif.Flags&net.FlagUp != 0 }
func isLoopback(nif *net.Interface) bool { return nif.Flags&net.FlagLoopback != 0 }
@ -300,9 +258,9 @@ func (s *State) String() string {
}
}
sb.WriteString("ifs={")
ifs := make([]string, 0, len(s.Interface))
var ifs []string
for k := range s.Interface {
if anyInterestingIP(s.InterfaceIPs[k]) {
if s.keepInterfaceInStringSummary(k) {
ifs = append(ifs, k)
}
}
@ -318,23 +276,40 @@ func (s *State) String() string {
if i > 0 {
sb.WriteString(" ")
}
if s.Interface[ifName].IsUp() {
fmt.Fprintf(&sb, "%s:[", ifName)
needSpace := false
for _, pfx := range s.InterfaceIPs[ifName] {
if !isInterestingIP(pfx.Addr()) {
continue
}
if needSpace {
sb.WriteString(" ")
}
fmt.Fprintf(&sb, "%s", pfx)
needSpace = true
}
sb.WriteString("]")
} else {
fmt.Fprintf(&sb, "%s:down", ifName)
iface := s.Interface[ifName]
if iface.Interface == nil {
fmt.Fprintf(&sb, "%s:nil", ifName)
continue
}
if !iface.IsUp() {
fmt.Fprintf(&sb, "%s:down", ifName)
continue
}
fmt.Fprintf(&sb, "%s:[", ifName)
needSpace := false
for _, pfx := range s.InterfaceIPs[ifName] {
a := pfx.Addr()
if a.IsMulticast() {
continue
}
fam := "4"
if a.Is6() {
fam = "6"
}
if needSpace {
sb.WriteString(" ")
}
needSpace = true
switch {
case a.IsLoopback():
fmt.Fprintf(&sb, "lo%s", fam)
case a.IsLinkLocalUnicast():
fmt.Fprintf(&sb, "llu%s", fam)
default:
fmt.Fprintf(&sb, "%s", pfx)
}
}
sb.WriteString("]")
}
sb.WriteString("}")
@ -351,18 +326,8 @@ func (s *State) String() string {
return sb.String()
}
// An InterfaceFilter indicates whether EqualFiltered should use i when deciding whether two States are equal.
// ips are all the IPPrefixes associated with i.
type InterfaceFilter func(i Interface, ips []netip.Prefix) bool
// An IPFilter indicates whether EqualFiltered should use ip when deciding whether two States are equal.
// ip is an ip address associated with some interface under consideration.
type IPFilter func(ip netip.Addr) bool
// EqualFiltered reports whether s and s2 are equal,
// considering only interfaces in s for which filter returns true,
// and considering only IPs for those interfaces for which filterIP returns true.
func (s *State) EqualFiltered(s2 *State, useInterface InterfaceFilter, useIP IPFilter) bool {
// Equal reports whether s and s2 are exactly equal.
func (s *State) Equal(s2 *State) bool {
if s == nil && s2 == nil {
return true
}
@ -378,19 +343,16 @@ func (s *State) EqualFiltered(s2 *State, useInterface InterfaceFilter, useIP IPF
return false
}
for iname, i := range s.Interface {
ips := s.InterfaceIPs[iname]
if !useInterface(i, ips) {
continue
}
i2, ok := s2.Interface[iname]
if !ok {
return false
}
ips2, ok := s2.InterfaceIPs[iname]
if !ok {
if !i.Equal(i2) {
return false
}
if !interfacesEqual(i, i2) || !prefixesEqualFiltered(ips, ips2, useIP) {
}
for iname, vv := range s.InterfaceIPs {
if !slices.Equal(vv, s2.InterfaceIPs[iname]) {
return false
}
}
@ -413,60 +375,23 @@ func (s *State) HasIP(ip netip.Addr) bool {
return false
}
func interfacesEqual(a, b Interface) bool {
return a.Index == b.Index &&
func (a Interface) Equal(b Interface) bool {
if (a.Interface == nil) != (b.Interface == nil) {
return false
}
if !(a.Desc == b.Desc && netAddrsEqual(a.AltAddrs, b.AltAddrs)) {
return false
}
if a.Interface != nil && !(a.Index == b.Index &&
a.MTU == b.MTU &&
a.Name == b.Name &&
a.Flags == b.Flags &&
bytes.Equal([]byte(a.HardwareAddr), []byte(b.HardwareAddr))
}
func filteredIPPs(ipps []netip.Prefix, useIP IPFilter) []netip.Prefix {
// TODO: rewrite prefixesEqualFiltered to avoid making copies
x := make([]netip.Prefix, 0, len(ipps))
for _, ipp := range ipps {
if useIP(ipp.Addr()) {
x = append(x, ipp)
}
}
return x
}
func prefixesEqualFiltered(a, b []netip.Prefix, useIP IPFilter) bool {
return prefixesEqual(filteredIPPs(a, useIP), filteredIPPs(b, useIP))
}
func prefixesEqual(a, b []netip.Prefix) bool {
if len(a) != len(b) {
bytes.Equal([]byte(a.HardwareAddr), []byte(b.HardwareAddr))) {
return false
}
for i, v := range a {
if b[i] != v {
return false
}
}
return true
}
// UseInterestingInterfaces is an InterfaceFilter that reports whether i is an interesting interface.
// An interesting interface if it is (a) not owned by Tailscale and (b) routes interesting IP addresses.
// See UseInterestingIPs for the definition of an interesting IP address.
func UseInterestingInterfaces(i Interface, ips []netip.Prefix) bool {
return !isTailscaleInterface(i.Name, ips) && anyInterestingIP(ips)
}
// UseInterestingIPs is an IPFilter that reports whether ip is an interesting IP address.
// An IP address is interesting if it is neither a loopback nor a link local unicast IP address.
func UseInterestingIPs(ip netip.Addr) bool {
return isInterestingIP(ip)
}
// UseAllInterfaces is an InterfaceFilter that includes all interfaces.
func UseAllInterfaces(i Interface, ips []netip.Prefix) bool { return true }
// UseAllIPs is an IPFilter that includes all IPs.
func UseAllIPs(ips netip.Addr) bool { return true }
func (s *State) HasPAC() bool { return s != nil && s.PAC != "" }
// AnyInterfaceUp reports whether any interface seems like it has Internet access.
@ -477,6 +402,18 @@ func (s *State) AnyInterfaceUp() bool {
return s != nil && (s.HaveV4 || s.HaveV6)
}
func netAddrsEqual(a, b []net.Addr) bool {
if len(a) != len(b) {
return false
}
for i, av := range a {
if av.Network() != b[i].Network() || av.String() != b[i].String() {
return false
}
}
return true
}
func hasTailscaleIP(pfxs []netip.Prefix) bool {
for _, pfx := range pfxs {
if tsaddr.IsTailscaleIP(pfx.Addr()) {
@ -664,11 +601,23 @@ func isUsableV6(ip netip.Addr) bool {
v6Global1 = netip.MustParsePrefix("2000::/3")
)
// anyInterestingIP reports whether pfxs contains any IP that matches
// isInterestingIP.
func anyInterestingIP(pfxs []netip.Prefix) bool {
for _, pfx := range pfxs {
if isInterestingIP(pfx.Addr()) {
// keepInterfaceInStringSummary reports whether the named interface should be included
// in the String method's summary string.
func (s *State) keepInterfaceInStringSummary(ifName string) bool {
iface, ok := s.Interface[ifName]
if !ok || iface.Interface == nil {
return false
}
if ifName == s.DefaultRouteInterface {
return true
}
up := iface.IsUp()
for _, p := range s.InterfaceIPs[ifName] {
a := p.Addr()
if a.IsLinkLocalUnicast() || a.IsLoopback() {
continue
}
if up || a.IsGlobalUnicast() || a.IsPrivate() {
return true
}
}
@ -677,9 +626,12 @@ func anyInterestingIP(pfxs []netip.Prefix) bool {
// isInterestingIP reports whether ip is an interesting IP that we
// should log in interfaces.State logging. We don't need to show
// localhost or link-local addresses.
// loopback, link-local addresses, or non-Tailscale ULA addresses.
func isInterestingIP(ip netip.Addr) bool {
return !ip.IsLoopback() && !ip.IsLinkLocalUnicast()
if ip.IsLoopback() || ip.IsLinkLocalUnicast() {
return false
}
return true
}
var altNetInterfaces func() ([]Interface, error)

168
net/interfaces/interfaces_test.go
View File

@ -23,19 +23,6 @@ func TestGetState(t *testing.T) {
}
t.Logf("Got: %s", j)
t.Logf("As string: %s", st)
st2, err := GetState()
if err != nil {
t.Fatal(err)
}
if !st.EqualFiltered(st2, UseAllInterfaces, UseAllIPs) {
// let's assume nobody was changing the system network interfaces between
// the two GetState calls.
t.Fatal("two States back-to-back were not equal")
}
t.Logf("As string:\n\t%s", st)
}
func TestLikelyHomeRouterIP(t *testing.T) {
@ -154,7 +141,7 @@ func TestIsUsableV6(t *testing.T) {
{"first ULA", "fc00::1", true},
{"Tailscale", "fd7a:115c:a1e0::1", false},
{"Cloud Run", "fddf:3978:feb1:d745::1", true},
{"zeros", "0000:0000:0000:0000:0000:0000:0000:0000", false},
{"zeros", "0::0", false},
{"Link Local", "fe80::1", false},
{"Global", "2602::1", true},
{"IPv4 public", "192.0.2.1", false},
@ -168,41 +155,6 @@ func TestIsUsableV6(t *testing.T) {
}
}
func TestStateEqualFilteredIPFilter(t *testing.T) {
// s1 and s2 are identical, except that an "interesting" interface
// has gained an "uninteresting" IP address.
s1 := &State{
InterfaceIPs: map[string][]netip.Prefix{"x": {
netip.MustParsePrefix("42.0.0.0/8"),
netip.MustParsePrefix("169.254.0.0/16"), // link local unicast
}},
Interface: map[string]Interface{"x": {Interface: &net.Interface{Name: "x"}}},
}
s2 := &State{
InterfaceIPs: map[string][]netip.Prefix{"x": {
netip.MustParsePrefix("42.0.0.0/8"),
netip.MustParsePrefix("169.254.0.0/16"), // link local unicast
netip.MustParsePrefix("127.0.0.0/8"), // loopback (added)
}},
Interface: map[string]Interface{"x": {Interface: &net.Interface{Name: "x"}}},
}
// s1 and s2 are different...
if s1.EqualFiltered(s2, UseAllInterfaces, UseAllIPs) {
t.Errorf("%+v != %+v", s1, s2)
}
// ...and they look different if you only restrict to interesting interfaces...
if s1.EqualFiltered(s2, UseInterestingInterfaces, UseAllIPs) {
t.Errorf("%+v != %+v when restricting to interesting interfaces _but not_ IPs", s1, s2)
}
// ...but because the additional IP address is uninteresting, we should treat them as the same.
if !s1.EqualFiltered(s2, UseInterestingInterfaces, UseInterestingIPs) {
t.Errorf("%+v == %+v when restricting to interesting interfaces and IPs", s1, s2)
}
}
func TestStateString(t *testing.T) {
tests := []struct {
name string
@ -222,11 +174,15 @@ func TestStateString(t *testing.T) {
"wlan0": {
Interface: &net.Interface{},
},
"lo": {
Interface: &net.Interface{},
},
},
InterfaceIPs: map[string][]netip.Prefix{
"eth0": {
netip.MustParsePrefix("10.0.0.2/8"),
},
"lo": {},
},
HaveV4: true,
},
@ -239,10 +195,13 @@ func TestStateString(t *testing.T) {
Interface: map[string]Interface{
"foo": {
Desc: "a foo thing",
Interface: &net.Interface{
Flags: net.FlagUp,
},
},
},
},
want: `interfaces.State{defaultRoute=foo (a foo thing) ifs={} v4=false v6=false}`,
want: `interfaces.State{defaultRoute=foo (a foo thing) ifs={foo:[]} v4=false v6=false}`,
},
}
for _, tt := range tests {
@ -254,3 +213,112 @@ func TestStateString(t *testing.T) {
})
}
}
func TestIsInterestingIP(t *testing.T) {
tests := []struct {
ip string
want bool
}{
{"fd7a:115c:a1e0:ab12:4843:cd96:624a:4603", true}, // Tailscale private ULA
{"fd15:bbfa:c583:4fce:f4fb:4ff:fe1a:4148", true}, // Other private ULA
{"10.2.3.4", true},
{"127.0.0.1", false},
{"::1", false},
{"2001::2", true},
{"169.254.1.2", false},
{"fe80::1", false},
}
for _, tt := range tests {
if got := isInterestingIP(netip.MustParseAddr(tt.ip)); got != tt.want {
t.Errorf("isInterestingIP(%q) = %v, want %v", tt.ip, got, tt.want)
}
}
}
// tests (*State).Equal
func TestEqual(t *testing.T) {
tests := []struct {
name string
s1, s2 *State
want bool // implies !wantMajor
}{
{
name: "eq_nil",
want: true,
},
{
name: "nil_mix",
s2: new(State),
want: false,
},
{
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: true,
},
{
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: false,
},
{
name: "some-interface-ips-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: false,
},
{
name: "altaddrs-changed",
s1: &State{
Interface: map[string]Interface{
"foo": {AltAddrs: []net.Addr{&net.TCPAddr{IP: net.ParseIP("1.2.3.4")}}},
},
},
s2: &State{
Interface: map[string]Interface{
"foo": {AltAddrs: []net.Addr{&net.TCPAddr{IP: net.ParseIP("5.6.7.8")}}},
},
},
want: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := tt.s2.Equal(tt.s1); got != tt.want {
t.Errorf("Equal = %v; want %v", got, tt.want)
}
})
}
}

100
net/netmon/netmon.go
View File

@ -55,6 +55,10 @@ type Monitor struct {
change chan bool // send false to wake poller, true to also force ChangeDeltas be sent
stop chan struct{} // closed on Stop
// Things that must be set early, before use,
// and not change at runtime.
tsIfName string // tailscale interface name, if known/set ("tailscale0", "utun3", ...)
mu sync.Mutex // guards all following fields
cbs set.HandleSet[ChangeFunc]
ruleDelCB set.HandleSet[RuleDeleteCallback]
@ -76,6 +80,9 @@ type Monitor struct {
// ChangeDelta describes the difference between two network states.
type ChangeDelta struct {
// Monitor is the network monitor that sent this delta.
Monitor *Monitor
// Old is the old interface state, if known.
// It's nil if the old state is unknown.
// Do not mutate it.
@ -145,6 +152,15 @@ func (m *Monitor) interfaceStateUncached() (*interfaces.State, error) {
return interfaces.GetState()
}
// SetTailscaleInterfaceName sets the name of the Tailscale interface. For
// example, "tailscale0", "tun0", "utun3", etc.
//
// This must be called only early in tailscaled startup before the monitor is
// used.
func (m *Monitor) SetTailscaleInterfaceName(ifName string) {
m.tsIfName = ifName
}
// GatewayAndSelfIP returns the current network's default gateway, and
// the machine's default IP for that gateway.
//
@ -320,7 +336,11 @@ func (m *Monitor) notifyRuleDeleted(rdm ipRuleDeletedMessage) {
// considered when checking for network state changes.
// The ips parameter should be the IPs of the provided interface.
func (m *Monitor) isInterestingInterface(i interfaces.Interface, ips []netip.Prefix) bool {
return m.om.IsInterestingInterface(i.Name) && interfaces.UseInterestingInterfaces(i, ips)
if !m.om.IsInterestingInterface(i.Name) {
return false
}
return true
}
// debounce calls the callback function with a delay between events
@ -358,18 +378,19 @@ func (m *Monitor) handlePotentialChange(newState *interfaces.State, forceCallbac
defer m.mu.Unlock()
oldState := m.ifState
timeJumped := shouldMonitorTimeJump && m.checkWallTimeAdvanceLocked()
if !timeJumped && !forceCallbacks && oldState.EqualFiltered(newState, interfaces.UseAllInterfaces, interfaces.UseAllIPs) {
if !timeJumped && !forceCallbacks && oldState.Equal(newState) {
// Exactly equal. Nothing to do.
return
}
delta := &ChangeDelta{
Monitor: m,
Old: oldState,
New: newState,
TimeJumped: timeJumped,
}
delta.Major = !newState.EqualFiltered(oldState, m.isInterestingInterface, interfaces.UseInterestingIPs)
delta.Major = m.IsMajorChangeFrom(oldState, newState)
if delta.Major {
m.gwValid = false
m.ifState = newState
@ -394,6 +415,79 @@ func (m *Monitor) handlePotentialChange(newState *interfaces.State, forceCallbac
}
}
// IsMajorChangeFrom reports whether the transition from s1 to s2 is
// a "major" change, where major roughly means it's worth tearing down
// a bunch of connections and rebinding.
//
// TODO(bradiftz): tigten this definition.
func (m *Monitor) IsMajorChangeFrom(s1, s2 *interfaces.State) bool {
if s1 == nil && s2 == nil {
return false
}
if s1 == nil || s2 == nil {
return true
}
if s1.HaveV6 != s2.HaveV6 ||
s1.HaveV4 != s2.HaveV4 ||
s1.IsExpensive != s2.IsExpensive ||
s1.DefaultRouteInterface != s2.DefaultRouteInterface ||
s1.HTTPProxy != s2.HTTPProxy ||
s1.PAC != s2.PAC {
return true
}
for iname, i := range s1.Interface {
if iname == m.tsIfName {
// Ignore changes in the Tailscale interface itself.
continue
}
ips := s1.InterfaceIPs[iname]
if !m.isInterestingInterface(i, ips) {
continue
}
i2, ok := s2.Interface[iname]
if !ok {
return true
}
ips2, ok := s2.InterfaceIPs[iname]
if !ok {
return true
}
if !i.Equal(i2) || !prefixesMajorEqual(ips, ips2) {
return true
}
}
return false
}
// prefixesMajorEqual reports whether a and b are equal after ignoring
// boring things like link-local, loopback, and multicast addresses.
func prefixesMajorEqual(a, b []netip.Prefix) bool {
// trim returns a subslice of p with link local unicast,
// loopback, and multicast prefixes removed from the front.
trim := func(p []netip.Prefix) []netip.Prefix {
for len(p) > 0 {
a := p[0].Addr()
if a.IsLinkLocalUnicast() || a.IsLoopback() || a.IsMulticast() {
p = p[1:]
continue
}
break
}
return p
}
for {
a = trim(a)
b = trim(b)
if len(a) == 0 || len(b) == 0 {
return len(a) == 0 && len(b) == 0
}
if a[0] != b[0] {
return false
}
a, b = a[1:], b[1:]
}
}
func jsonSummary(x any) any {
j, err := json.Marshal(x)
if err != nil {

132
net/netmon/netmon_test.go
View File

@ -5,9 +5,14 @@
import (
"flag"
"net"
"net/netip"
"sync/atomic"
"testing"
"time"
"tailscale.com/net/interfaces"
"tailscale.com/util/mak"
)
func TestMonitorStartClose(t *testing.T) {
@ -108,3 +113,130 @@ func TestMonitorMode(t *testing.T) {
t.Logf("%v callbacks", n)
}
}
// tests (*State).IsMajorChangeFrom
func TestIsMajorChangeFrom(t *testing.T) {
type State = interfaces.State
type Interface = interfaces.Interface
tests := []struct {
name string
s1, s2 *State
want bool
}{
{
name: "eq_nil",
want: false,
},
{
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: "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,
},
{
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"),
// Brad saw this address coming & going on his home LAN, possibly
// via an Apple TV Thread routing advertisement? (Issue 9040)
netip.MustParsePrefix("fd15:bbfa:c583:4fce:f4fb:4ff:fe1a:4148/64"),
},
},
},
want: true, // TODO(bradfitz): want false (ignore the IPv6 ULA address on foo)
},
}
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,
}})
}
}
}
var m Monitor
m.om = &testOSMon{
Interesting: func(name string) bool { return true },
}
if got := m.IsMajorChangeFrom(tt.s1, tt.s2); got != tt.want {
t.Errorf("IsMajorChange = %v; want %v", got, tt.want)
}
})
}
}
type testOSMon struct {
osMon
Interesting func(name string) bool
}
func (m *testOSMon) IsInterestingInterface(name string) bool {
if m.Interesting == nil {
return true
}
return m.Interesting(name)
}

31
net/netns/netns_darwin.go
View File

@ -20,6 +20,7 @@
"tailscale.com/envknob"
"tailscale.com/net/interfaces"
"tailscale.com/net/netmon"
"tailscale.com/net/tsaddr"
"tailscale.com/types/logger"
)
@ -110,7 +111,7 @@ func getInterfaceIndex(logf logger.Logf, netMon *netmon.Monitor, address string)
// Verify that we didn't just choose the Tailscale interface;
// if so, we fall back to binding from the default.
_, tsif, err2 := interfaces.Tailscale()
tsif, err2 := tailscaleInterface()
if err2 == nil && tsif != nil && tsif.Index == idx {
logf("[unexpected] netns: interfaceIndexFor returned Tailscale interface")
return defaultIdx()
@ -119,6 +120,34 @@ func getInterfaceIndex(logf logger.Logf, netMon *netmon.Monitor, address string)
return idx, err
}
// tailscaleInterface returns the current machine's Tailscale interface, if any.
// If none is found, (nil, nil) is returned.
// A non-nil error is only returned on a problem listing the system interfaces.
func tailscaleInterface() (*net.Interface, error) {
ifs, err := net.Interfaces()
if err != nil {
return nil, err
}
for _, iface := range ifs {
if !strings.HasPrefix(iface.Name, "utun") {
continue
}
addrs, err := iface.Addrs()
if err != nil {
continue
}
for _, a := range addrs {
if ipnet, ok := a.(*net.IPNet); ok {
nip, ok := netip.AddrFromSlice(ipnet.IP)
if ok && tsaddr.IsTailscaleIP(nip.Unmap()) {
return &iface, nil
}
}
}
}
return nil, nil
}
// interfaceIndexFor returns the interface index that we should bind to in
// order to send traffic to the provided address.
func interfaceIndexFor(addr netip.Addr, canRecurse bool) (int, error) {

2
net/netns/netns_darwin_test.go
View File

@ -55,7 +55,7 @@ func TestGetInterfaceIndex(t *testing.T) {
}
t.Run("NoTailscale", func(t *testing.T) {
_, tsif, err := interfaces.Tailscale()
tsif, err := tailscaleInterface()
if err != nil {
t.Fatal(err)
}