You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
tailscale/wgengine/tsdns/tsdns_test.go

249 lines
6.2 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 tsdns
import (
"bytes"
"sync"
"testing"
dns "golang.org/x/net/dns/dnsmessage"
"inet.af/netaddr"
"tailscale.com/wgengine/packet"
)
var dnsMap = &Map{
domainToIP: map[string]netaddr.IP{
"test1.ipn.dev": netaddr.IPv4(1, 2, 3, 4),
"test2.ipn.dev": netaddr.IPv4(5, 6, 7, 8),
},
}
func dnspacket(srcip, dstip packet.IP, domain string, tp dns.Type, response bool) *packet.ParsedPacket {
dnsHeader := dns.Header{Response: response}
question := dns.Question{
Name: dns.MustNewName(domain),
Type: tp,
Class: dns.ClassINET,
}
udpHeader := &packet.UDPHeader{
IPHeader: packet.IPHeader{
SrcIP: srcip,
DstIP: dstip,
IPProto: packet.UDP,
},
SrcPort: 1234,
DstPort: 53,
}
builder := dns.NewBuilder(nil, dnsHeader)
builder.StartQuestions()
builder.Question(question)
payload, _ := builder.Finish()
buf := packet.Generate(udpHeader, payload)
pp := new(packet.ParsedPacket)
pp.Decode(buf)
return pp
}
func TestAcceptsPacket(t *testing.T) {
r := NewResolver(t.Logf)
r.SetMap(dnsMap)
src := packet.IP(0x64656667) // 100.101.102.103
dst := packet.IP(0x64646464) // 100.100.100.100
tests := []struct {
name string
request *packet.ParsedPacket
want bool
}{
{"valid", dnspacket(src, dst, "test1.ipn.dev.", dns.TypeA, false), true},
{"invalid", dnspacket(dst, src, "test1.ipn.dev.", dns.TypeA, false), false},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
accepts := r.AcceptsPacket(tt.request)
if accepts != tt.want {
t.Errorf("accepts = %v; want %v", accepts, tt.want)
}
})
}
}
func TestResolve(t *testing.T) {
r := NewResolver(t.Logf)
r.SetMap(dnsMap)
tests := []struct {
name string
domain string
ip netaddr.IP
code dns.RCode
iserr bool
}{
{"valid", "test1.ipn.dev", netaddr.IPv4(1, 2, 3, 4), dns.RCodeSuccess, false},
{"nxdomain", "test3.ipn.dev", netaddr.IP{}, dns.RCodeNameError, true},
{"not our domain", "google.com", netaddr.IP{}, dns.RCodeRefused, true},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ip, code, err := r.Resolve(tt.domain)
if err != nil && !tt.iserr {
t.Errorf("err = %v; want nil", err)
} else if err == nil && tt.iserr {
t.Errorf("err = nil; want non-nil")
}
if code != tt.code {
t.Errorf("code = %v; want %v", code, tt.code)
}
// Only check ip for non-err
if !tt.iserr && ip != tt.ip {
t.Errorf("ip = %v; want %v", ip, tt.ip)
}
})
}
}
func TestConcurrentSet(t *testing.T) {
r := NewResolver(t.Logf)
// This is purely to ensure that Resolve does not race with SetMap.
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
r.SetMap(dnsMap)
}()
go func() {
defer wg.Done()
r.Resolve("test1.ipn.dev")
}()
wg.Wait()
}
var validResponse = []byte{
// IP header
0x45, 0x00, 0x00, 0x58, 0xff, 0xff, 0x00, 0x00, 0x40, 0x11, 0xe7, 0x00,
// Source IP
0x64, 0x64, 0x64, 0x64,
// Destination IP
0x64, 0x65, 0x66, 0x67,
// UDP header
0x00, 0x35, 0x04, 0xd2, 0x00, 0x44, 0x53, 0xdd,
// DNS payload
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
// Answer:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x04, // length: 4 bytes
0x01, 0x02, 0x03, 0x04, // A: 1.2.3.4
}
var nxdomainResponse = []byte{
// IP header
0x45, 0x00, 0x00, 0x3b, 0xff, 0xff, 0x00, 0x00, 0x40, 0x11, 0xe7, 0x1d,
// Source IP
0x64, 0x64, 0x64, 0x64,
// Destination IP
0x64, 0x65, 0x66, 0x67,
// UDP header
0x00, 0x35, 0x04, 0xd2, 0x00, 0x27, 0x25, 0x33,
// DNS payload
0x00, 0x00, // transaction id: 0
0x84, 0x03, // flags: response, authoritative, error: nxdomain
0x00, 0x01, // one question
0x00, 0x00, // no answers
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x33, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
}
func TestFull(t *testing.T) {
r := NewResolver(t.Logf)
r.SetMap(dnsMap)
src := packet.IP(0x64656667) // 100.101.102.103
dst := packet.IP(0x64646464) // 100.100.100.100
// One full packet and one error packet
tests := []struct {
name string
request *packet.ParsedPacket
response []byte
}{
{"valid", dnspacket(src, dst, "test1.ipn.dev.", dns.TypeA, false), validResponse},
{"error", dnspacket(src, dst, "test3.ipn.dev.", dns.TypeA, false), nxdomainResponse},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
buf := make([]byte, 512)
response, err := r.Respond(tt.request, buf)
if err != nil {
t.Errorf("err = %v; want nil", err)
}
if !bytes.Equal(response, tt.response) {
t.Errorf("response = %x; want %x", response, tt.response)
}
})
}
}
func TestAllocs(t *testing.T) {
r := NewResolver(t.Logf)
r.SetMap(dnsMap)
src := packet.IP(0x64656667) // 100.101.102.103
dst := packet.IP(0x64646464) // 100.100.100.100
query := dnspacket(src, dst, "test1.ipn.dev.", dns.TypeA, false)
buf := make([]byte, 512)
allocs := testing.AllocsPerRun(100, func() {
r.Respond(query, buf)
})
if allocs > 0 {
t.Errorf("allocs = %v; want 0", allocs)
}
}
func BenchmarkFull(b *testing.B) {
r := NewResolver(b.Logf)
r.SetMap(dnsMap)
src := packet.IP(0x64656667) // 100.101.102.103
dst := packet.IP(0x64646464) // 100.100.100.100
// One full packet and one error packet
tests := []struct {
name string
request *packet.ParsedPacket
}{
{"valid", dnspacket(src, dst, "test1.ipn.dev.", dns.TypeA, false)},
{"nxdomain", dnspacket(src, dst, "test3.ipn.dev.", dns.TypeA, false)},
}
buf := make([]byte, 512)
for _, tt := range tests {
b.Run(tt.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
r.Respond(tt.request, buf)
}
})
}
}