// Copyright (c) 2021 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 resolver
import (
"flag"
"fmt"
"reflect"
"strings"
"testing"
"time"
dns "golang.org/x/net/dns/dnsmessage"
"tailscale.com/hostinfo"
"tailscale.com/types/dnstype"
)
func (rr resolverAndDelay) String() string {
return fmt.Sprintf("%v+%v", rr.name, rr.startDelay)
}
func TestResolversWithDelays(t *testing.T) {
// query
q := func(ss ...string) (ipps []*dnstype.Resolver) {
for _, host := range ss {
ipps = append(ipps, &dnstype.Resolver{Addr: host})
}
return
}
// output
o := func(ss ...string) (rr []resolverAndDelay) {
for _, s := range ss {
var d time.Duration
s, durStr, hasPlus := strings.Cut(s, "+")
if hasPlus {
var err error
d, err = time.ParseDuration(durStr)
if err != nil {
panic(fmt.Sprintf("parsing duration in %q: %v", s, err))
}
}
rr = append(rr, resolverAndDelay{
name: &dnstype.Resolver{Addr: s},
startDelay: d,
})
}
return
}
tests := []struct {
name string
in []*dnstype.Resolver
want []resolverAndDelay
}{
{
name: "unknown-no-delays",
in: q("1.2.3.4", "2.3.4.5"),
want: o("1.2.3.4", "2.3.4.5"),
},
{
name: "google-all-ipv4",
in: q("8.8.8.8", "8.8.4.4"),
want: o("https://dns.google/dns-query", "8.8.8.8+0.5s", "8.8.4.4+0.7s"),
},
{
name: "google-only-ipv6",
in: q("2001:4860:4860::8888", "2001:4860:4860::8844"),
want: o("https://dns.google/dns-query", "2001:4860:4860::8888+0.5s", "2001:4860:4860::8844+0.7s"),
},
{
name: "google-all-four",
in: q("8.8.8.8", "8.8.4.4", "2001:4860:4860::8888", "2001:4860:4860::8844"),
want: o("https://dns.google/dns-query", "8.8.8.8+0.5s", "8.8.4.4+0.7s", "2001:4860:4860::8888+0.5s", "2001:4860:4860::8844+0.7s"),
},
{
name: "quad9-one-v4-one-v6",
in: q("9.9.9.9", "2620:fe::fe"),
want: o("https://dns.quad9.net/dns-query", "9.9.9.9+0.5s", "2620:fe::fe+0.5s"),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := resolversWithDelays(tt.in)
if !reflect.DeepEqual(got, tt.want) {
t.Errorf("got %v; want %v", got, tt.want)
}
})
}
}
func TestGetRCode(t *testing.T) {
tests := []struct {
name string
packet []byte
want dns.RCode
}{
{
name: "empty",
packet: []byte{},
want: dns.RCode(5),
},
{
name: "too-short",
packet: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
want: dns.RCode(5),
},
{
name: "noerror",
packet: []byte{0xC4, 0xFE, 0x81, 0xA0, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01},
want: dns.RCode(0),
},
{
name: "refused",
packet: []byte{0xee, 0xa1, 0x81, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
want: dns.RCode(5),
},
{
name: "nxdomain",
packet: []byte{0x34, 0xf4, 0x81, 0x83, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01},
want: dns.RCode(3),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := getRCode(tt.packet)
if got != tt.want {
t.Errorf("got %d; want %d", got, tt.want)
}
})
}
}
func TestMaxDoHInFlight(t *testing.T) {
tests := []struct {
goos string
ver string
want int
}{
{"ios", "", 10},
{"ios", "1532", 10},
{"ios", "9.3.2", 10},
{"ios", "14.3.2", 10},
{"ios", "15.3.2", 1000},
{"ios", "20.3.2", 1000},
{"android", "", 1000},
{"darwin", "", 1000},
{"linux", "", 1000},
}
for _, tc := range tests {
t.Run(fmt.Sprintf("%s-%s", tc.goos, tc.ver), func(t *testing.T) {
hostinfo.SetOSVersion(tc.ver)
got := maxDoHInFlight(tc.goos)
if got != tc.want {
t.Errorf("got %d; want %d", got, tc.want)
}
})
}
}
var testDNS = flag.Bool("test-dns", false, "run tests that require a working DNS server")
func TestGetKnownDoHClientForProvider(t *testing.T) {
var fwd forwarder
c, ok := fwd.getKnownDoHClientForProvider("https://dns.google/dns-query")
if !ok {
t.Fatal("not found")
}
if !*testDNS {
t.Skip("skipping without --test-dns")
}
res, err := c.Head("https://dns.google/")
if err != nil {
t.Fatal(err)
}
defer res.Body.Close()
t.Logf("Got: %+v", res)
}
func BenchmarkNameFromQuery(b *testing.B) {
builder := dns.NewBuilder(nil, dns.Header{})
builder.StartQuestions()
builder.Question(dns.Question{
Name: dns.MustNewName("foo.example."),
Type: dns.TypeA,
Class: dns.ClassINET,
})
msg, err := builder.Finish()
if err != nil {
b.Fatal(err)
}
b.ResetTimer()
b.ReportAllocs()
for i := 0; i < b.N; i++ {
_, err := nameFromQuery(msg)
if err != nil {
b.Fatal(err)
}
}
}
// Reproduces https://github.com/tailscale/tailscale/issues/2533
// Fixed by https://github.com/tailscale/tailscale/commit/f414a9cc01f3264912513d07c0244ff4f3e4ba54
//
// NOTE: fuzz tests act like unit tests when run without `-fuzz`
func FuzzClampEDNSSize(f *testing.F) {
// Empty DNS packet
f.Add([]byte{
// query id
0x12, 0x34,
// flags: standard query, recurse
0x01, 0x20,
// num questions
0x00, 0x00,
// num answers
0x00, 0x00,
// num authority RRs
0x00, 0x00,
// num additional RRs
0x00, 0x00,
})
// Empty OPT
f.Add([]byte{
// header
0xaf, 0x66, 0x01, 0x20, 0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x01,
// query
0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f,
0x6d, 0x00, 0x00, 0x01, 0x00, 0x01,
// OPT
0x00, // name: <root>
0x00, 0x29, // type: OPT
0x10, 0x00, // UDP payload size
0x00, // higher bits in extended RCODE
0x00, // EDNS0 version
0x80, 0x00, // "Z" field
0x00, 0x00, // data length
})
// Query for "google.com"
f.Add([]byte{
// header
0xaf, 0x66, 0x01, 0x20, 0x00, 0x01, 0x00, 0x00,
0x00, 0x00, 0x00, 0x01,
// query
0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f,
0x6d, 0x00, 0x00, 0x01, 0x00, 0x01,
// OPT
0x00, 0x00, 0x29, 0x10, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00,
0x0c, 0x00, 0x0a, 0x00, 0x08, 0x62, 0x18, 0x1a, 0xcb, 0x19,
0xd7, 0xee, 0x23,
})
f.Fuzz(func(t *testing.T, data []byte) {
clampEDNSSize(data, maxResponseBytes)
})
}