tailscale/wgengine/router/ifconfig_windows_test.go
Tom 2903d42921
wgengine/router: delete hardcoded link-local address on Windows (#4740)
Fixes #4647

It seems that Windows creates a link-local address for the TUN driver, seemingly
based on the (fixed) adapter GUID. This results in a fixed MAC address, which
for some reason doesn't handle loopback correctly. Given the derived link-local
address is preferred for lookups (thanks LLMNR), traffic which addresses the
current node by hostname uses this broken address and never works.

To address this, we remove the broken link-local address from the wintun adapter.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2022-05-27 14:42:55 -07:00

287 lines
7.0 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 router
import (
"fmt"
"math/rand"
"net"
"strings"
"testing"
"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
"inet.af/netaddr"
)
func randIP() net.IP {
b := byte(rand.Intn(3))
return net.IP{b, b, b, b}
}
func randRouteData() *winipcfg.RouteData {
return &winipcfg.RouteData{
Destination: net.IPNet{
IP: randIP(),
Mask: net.CIDRMask(rand.Intn(3)+1, 32),
},
NextHop: randIP(),
Metric: uint32(rand.Intn(3)),
}
}
func TestRouteLess(t *testing.T) {
type D = winipcfg.RouteData
ipnet := func(s string) net.IPNet {
ipp, err := netaddr.ParseIPPrefix(s)
if err != nil {
t.Fatalf("error parsing test data %q: %v", s, err)
}
return *ipp.IPNet()
}
tests := []struct {
ri, rj *winipcfg.RouteData
want bool
}{
{
ri: &D{Metric: 1},
rj: &D{Metric: 2},
want: true,
},
{
ri: &D{Destination: ipnet("1.1.0.0/16"), Metric: 2},
rj: &D{Destination: ipnet("2.2.0.0/16"), Metric: 1},
want: true,
},
{
ri: &D{Destination: ipnet("1.1.0.0/16"), Metric: 1},
rj: &D{Destination: ipnet("2.2.0.0/16"), Metric: 1},
want: true,
},
{
ri: &D{Destination: ipnet("1.1.0.0/32"), Metric: 2},
rj: &D{Destination: ipnet("1.1.0.0/16"), Metric: 1},
want: true,
},
{
ri: &D{Destination: ipnet("1.1.0.0/32"), Metric: 1},
rj: &D{Destination: ipnet("1.1.0.0/16"), Metric: 1},
want: true,
},
{
ri: &D{Destination: ipnet("1.1.0.0/16"), Metric: 1, NextHop: net.ParseIP("3.3.3.3")},
rj: &D{Destination: ipnet("1.1.0.0/16"), Metric: 1, NextHop: net.ParseIP("4.4.4.4")},
want: true,
},
}
for i, tt := range tests {
got := routeLess(tt.ri, tt.rj)
if got != tt.want {
t.Errorf("%v. less = %v; want %v", i, got, tt.want)
}
back := routeLess(tt.rj, tt.ri)
if back && got {
t.Errorf("%v. less both ways", i)
}
}
}
func TestRouteLessConsistent(t *testing.T) {
for i := 0; i < 10000; i++ {
ri := randRouteData()
rj := randRouteData()
if routeLess(ri, rj) && routeLess(rj, ri) {
t.Fatalf("both compare less to each other:\n\t%#v\nand\n\t%#v", ri, rj)
}
}
}
func equalNetIPs(a, b []*net.IPNet) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if netCompare(*a[i], *b[i]) != 0 {
return false
}
}
return true
}
func ipnet4(ip string, bits int) *net.IPNet {
return &net.IPNet{
IP: net.ParseIP(ip),
Mask: net.CIDRMask(bits, 32),
}
}
// each cidr can end in "[4]" to mean To4 form.
func nets(cidrs ...string) (ret []*net.IPNet) {
for _, s := range cidrs {
to4 := strings.HasSuffix(s, "[4]")
if to4 {
s = strings.TrimSuffix(s, "[4]")
}
ip, ipNet, err := net.ParseCIDR(s)
if err != nil {
panic(fmt.Sprintf("Bogus CIDR %q in test", s))
}
if to4 {
ip = ip.To4()
}
ipNet.IP = ip
ret = append(ret, ipNet)
}
return
}
func TestDeltaNets(t *testing.T) {
tests := []struct {
a, b []*net.IPNet
wantAdd, wantDel []*net.IPNet
}{
{
a: nets("1.2.3.4/24", "1.2.3.4/31", "1.2.3.3/32", "10.0.1.1/32", "100.0.1.1/32"),
b: nets("10.0.1.1/32", "100.0.2.1/32", "1.2.3.3/32", "1.2.3.4/24"),
wantAdd: nets("100.0.2.1/32"),
wantDel: nets("1.2.3.4/31", "100.0.1.1/32"),
},
{
a: nets("fe80::99d0:ec2d:b2e7:536b/64", "100.84.36.11/32"),
b: nets("100.84.36.11/32"),
wantDel: nets("fe80::99d0:ec2d:b2e7:536b/64"),
},
{
a: nets("100.84.36.11/32", "fe80::99d0:ec2d:b2e7:536b/64"),
b: nets("100.84.36.11/32"),
wantDel: nets("fe80::99d0:ec2d:b2e7:536b/64"),
},
{
a: nets("100.84.36.11/32", "fe80::99d0:ec2d:b2e7:536b/64"),
b: nets("100.84.36.11/32[4]"),
wantDel: nets("fe80::99d0:ec2d:b2e7:536b/64"),
},
{
a: excludeIPv6LinkLocal(nets("100.84.36.11/32", "fe80::99d0:ec2d:b2e7:536b/64")),
b: nets("100.84.36.11/32"),
wantDel: nets("fe80::99d0:ec2d:b2e7:536b/64"),
},
{
a: []*net.IPNet{
{
IP: net.ParseIP("1.2.3.4"),
Mask: net.IPMask{0xff, 0xff, 0xff, 0xff},
},
},
b: []*net.IPNet{
{
IP: net.ParseIP("1.2.3.4"),
Mask: net.IPMask{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
},
},
},
}
for i, tt := range tests {
add, del := deltaNets(tt.a, tt.b)
if !equalNetIPs(add, tt.wantAdd) {
t.Errorf("[%d] add:\n got: %v\n want: %v\n", i, add, tt.wantAdd)
}
if !equalNetIPs(del, tt.wantDel) {
t.Errorf("[%d] del:\n got: %v\n want: %v\n", i, del, tt.wantDel)
}
}
}
func formatRouteData(rds []*winipcfg.RouteData) string {
var b strings.Builder
for _, rd := range rds {
b.WriteString(fmt.Sprintf("%+v", rd))
}
return b.String()
}
func equalRouteDatas(a, b []*winipcfg.RouteData) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if routeDataCompare(a[i], b[i]) != 0 {
return false
}
}
return true
}
func TestFilterRoutes(t *testing.T) {
var h0 net.IP
in := []*winipcfg.RouteData{
// LinkLocal and Loopback routes.
{*ipnet4("169.254.0.0", 16), h0, 1},
{*ipnet4("169.254.255.255", 32), h0, 1},
{*ipnet4("127.0.0.0", 8), h0, 1},
{*ipnet4("127.255.255.255", 32), h0, 1},
// Local LAN routes.
{*ipnet4("192.168.0.0", 24), h0, 1},
{*ipnet4("192.168.0.255", 32), h0, 1},
{*ipnet4("192.168.1.0", 25), h0, 1},
{*ipnet4("192.168.1.127", 32), h0, 1},
// Some random other route.
{*ipnet4("192.168.2.23", 32), h0, 1},
// Our own tailscale address.
{*ipnet4("100.100.100.100", 32), h0, 1},
// Other tailscale addresses.
{*ipnet4("100.100.100.101", 32), h0, 1},
{*ipnet4("100.100.100.102", 32), h0, 1},
}
want := []*winipcfg.RouteData{
{*ipnet4("169.254.0.0", 16), h0, 1},
{*ipnet4("127.0.0.0", 8), h0, 1},
{*ipnet4("192.168.0.0", 24), h0, 1},
{*ipnet4("192.168.1.0", 25), h0, 1},
{*ipnet4("192.168.2.23", 32), h0, 1},
{*ipnet4("100.100.100.101", 32), h0, 1},
{*ipnet4("100.100.100.102", 32), h0, 1},
}
got := filterRoutes(in, mustCIDRs("100.100.100.100/32"))
if !equalRouteDatas(got, want) {
t.Errorf("\ngot: %v\n want: %v\n", formatRouteData(got), formatRouteData(want))
}
}
func TestDeltaRouteData(t *testing.T) {
var h0 net.IP
h1 := net.ParseIP("99.99.99.99")
h2 := net.ParseIP("99.99.9.99")
a := []*winipcfg.RouteData{
{*ipnet4("1.2.3.4", 32), h0, 1},
{*ipnet4("1.2.3.4", 24), h1, 2},
{*ipnet4("1.2.3.4", 24), h2, 1},
{*ipnet4("1.2.3.5", 32), h0, 1},
}
b := []*winipcfg.RouteData{
{*ipnet4("1.2.3.5", 32), h0, 1},
{*ipnet4("1.2.3.4", 24), h1, 2},
{*ipnet4("1.2.3.4", 24), h2, 2},
}
add, del := deltaRouteData(a, b)
wantAdd := []*winipcfg.RouteData{
{*ipnet4("1.2.3.4", 24), h2, 2},
}
wantDel := []*winipcfg.RouteData{
{*ipnet4("1.2.3.4", 32), h0, 1},
{*ipnet4("1.2.3.4", 24), h2, 1},
}
if !equalRouteDatas(add, wantAdd) {
t.Errorf("add:\n got: %v\n want: %v\n", formatRouteData(add), formatRouteData(wantAdd))
}
if !equalRouteDatas(del, wantDel) {
t.Errorf("del:\n got: %v\n want: %v\n", formatRouteData(del), formatRouteData(wantDel))
}
}