router7/internal/dns/dns_test.go

735 lines
20 KiB
Go

// Copyright 2018 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package dns
import (
"fmt"
"io/ioutil"
"net"
"net/http"
"net/http/httptest"
"net/url"
"os"
"strings"
"sync/atomic"
"testing"
"time"
"github.com/rtr7/router7/internal/dhcp4d"
"github.com/miekg/dns"
)
// TODO(later): upstream a dnstest.Recorder implementation
type recorder struct {
response *dns.Msg
}
func (r *recorder) WriteMsg(m *dns.Msg) error {
r.response = m
return nil
}
func (r *recorder) LocalAddr() net.Addr { return nil }
func (r *recorder) RemoteAddr() net.Addr { return nil }
func (r *recorder) Write([]byte) (int, error) { return 0, nil }
func (r *recorder) Close() error { return nil }
func (r *recorder) TsigStatus() error { return nil }
func (r *recorder) TsigTimersOnly(bool) {}
func (r *recorder) Hijack() {}
func TestNXDOMAIN(t *testing.T) {
r := &recorder{}
s := NewServer("localhost:0", "lan")
m := new(dns.Msg)
m.SetQuestion("foo.invalid.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.MsgHdr.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
}
func TestResolveError(t *testing.T) {
r := &recorder{}
s := NewServer("localhost:0", "lan")
s.upstream = []string{"266.266.266.266:53"}
m := new(dns.Msg)
m.SetQuestion("foo.invalid.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if r.response != nil {
t.Fatalf("r.response unexpectedly not nil: %v", r.response)
}
}
func TestResolveFallback(t *testing.T) {
s := NewServer("localhost:0", "lan")
s.upstream = []string{
"266.266.266.266:53",
dnsServerAddr(t, dns.HandlerFunc(func(w dns.ResponseWriter, r *dns.Msg) {
reply(w, r, " 3600 IN A 127.0.0.1")
})),
}
if err := resolveTestTarget(s, "google.ch.", net.ParseIP("127.0.0.1")); err != nil {
t.Fatal(err)
}
}
func dnsServerAddr(t *testing.T, h dns.Handler) string {
t.Helper()
pc, err := net.ListenPacket("udp", "localhost:0")
if err != nil {
t.Fatal(err)
}
go dns.ActivateAndServe(nil, pc, h)
return pc.LocalAddr().String()
}
func TestResolveFallbackOnce(t *testing.T) {
s := NewServer("localhost:0", "lan")
var slowHits uint32
s.upstream = []string{
dnsServerAddr(t, dns.HandlerFunc(func(w dns.ResponseWriter, r *dns.Msg) {
atomic.AddUint32(&slowHits, 1)
// trigger fallback by sending no reply
})),
dnsServerAddr(t, dns.HandlerFunc(func(w dns.ResponseWriter, r *dns.Msg) {
reply(w, r, " 3600 IN A 127.0.0.1")
})),
"266.266.266.266:53",
}
for i := 0; i < 2; i++ {
if err := resolveTestTarget(s, "google.ch.", net.ParseIP("127.0.0.1")); err != nil {
t.Fatal(err)
}
}
if got, want := atomic.LoadUint32(&slowHits), uint32(1); got != want {
t.Errorf("slow upstream server hits = %d, wanted %d", got, want)
}
}
func reply(w dns.ResponseWriter, r *dns.Msg, response string) {
rr, _ := dns.NewRR(r.Question[0].Name + response)
m := new(dns.Msg)
m.SetReply(r)
m.Answer = append(m.Answer, rr)
w.WriteMsg(m)
}
func TestResolveLatencySteering(t *testing.T) {
s := NewServer("localhost:0", "lan")
var slowHits uint32
s.upstream = []string{
dnsServerAddr(t, dns.HandlerFunc(func(w dns.ResponseWriter, r *dns.Msg) {
atomic.AddUint32(&slowHits, 1)
time.Sleep(10 * time.Millisecond)
reply(w, r, " 3600 IN A 127.0.0.1")
})),
dnsServerAddr(t, dns.HandlerFunc(func(w dns.ResponseWriter, r *dns.Msg) {
reply(w, r, " 3600 IN A 127.0.0.1")
})),
"266.266.266.266:53",
}
if err := resolveTestTarget(s, "google.ch.", net.ParseIP("127.0.0.1")); err != nil {
t.Fatal(err)
}
s.probeUpstreamLatency()
if err := resolveTestTarget(s, "google.ch.", net.ParseIP("127.0.0.1")); err != nil {
t.Fatal(err)
}
want := uint32(2) // one for resolving, one for probing
if got := atomic.LoadUint32(&slowHits); got != want {
t.Errorf("slow upstream server hits = %d, wanted %d", got, want)
}
}
func TestDHCPDomain(t *testing.T) {
s := NewServer("localhost:0", "example.org")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
},
})
t.Run("testtarget.lan.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget.example.org.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
})
}
func TestDHCP(t *testing.T) {
r := &recorder{}
s := NewServer("localhost:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
},
})
t.Run("testtarget.lan.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
})
expired := time.Now().Add(-1 * time.Second)
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
Expiry: time.Now().Add(1 * time.Minute),
},
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 150},
Expiry: expired,
},
{
Hostname: "aged",
Addr: net.IP{192, 168, 42, 42},
Expiry: time.Now().Add(1 * time.Minute),
},
})
t.Run("testtarget.lan. (expired)", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
})
t.Run("notfound.lan.", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("notfound.lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
})
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "aged",
Addr: net.IP{192, 168, 42, 42},
Expiry: expired,
},
})
t.Run("aged.lan. (expired)", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("aged.lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
})
}
func TestHostname(t *testing.T) {
hostname, err := os.Hostname()
if err != nil {
t.Skipf("os.Hostname: %v", err)
}
r := &recorder{}
s := NewServer("127.0.0.2:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: strings.ToUpper(hostname),
Addr: net.IP{192, 168, 42, 23},
},
})
t.Run("A", func(t *testing.T) {
for _, hostname := range []string{
hostname,
strings.ToUpper(hostname),
} {
t.Run(hostname, func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion(hostname+".lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers for %v: got %d, want %d", m.Question, got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.A); !ok {
t.Fatalf("unexpected response type: got %T, want dns.A", a)
}
if got, want := a.(*dns.A).A, net.ParseIP("127.0.0.2"); !got.Equal(want) {
t.Fatalf("unexpected response IP: got %v, want %v", got, want)
}
})
}
})
t.Run("PTR", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("2.0.0.127.in-addr.arpa.", dns.TypePTR)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers: got %d, want %d", got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.PTR); !ok {
t.Fatalf("unexpected response type: got %T, want dns.PTR", a)
}
if got, want := a.(*dns.PTR).Ptr, hostname+".lan."; got != want {
t.Fatalf("unexpected response record: got %q, want %q", got, want)
}
})
t.Run("MoreRecent", func(t *testing.T) {
now := time.Now()
older := dhcp4d.Lease{
Hostname: "xps",
Addr: net.IP{192, 168, 42, 23},
Expiry: now.Add(1 * time.Second),
}
newer := dhcp4d.Lease{
Hostname: "xps",
Addr: net.IP{192, 168, 42, 42},
Expiry: now.Add(2 * time.Second),
}
for _, tt := range []struct {
name string
order []dhcp4d.Lease
}{
{
name: "older, newer",
order: []dhcp4d.Lease{older, newer},
},
{
name: "newer, older",
order: []dhcp4d.Lease{newer, older},
},
} {
t.Run(tt.name, func(t *testing.T) {
s.SetLeases(tt.order)
m := new(dns.Msg)
m.SetQuestion("xps.lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers for %v: got %d, want %d", m.Question, got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.A); !ok {
t.Fatalf("unexpected response type: got %T, want dns.A", a)
}
if got, want := a.(*dns.A).A, net.ParseIP("192.168.42.42"); !got.Equal(want) {
t.Fatalf("unexpected response IP: got %v, want %v", got, want)
}
})
}
})
}
func TestHostnameDHCP(t *testing.T) {
hostname, err := os.Hostname()
if err != nil {
t.Skipf("os.Hostname: %v", err)
}
r := &recorder{}
s := NewServer("127.0.0.2:0", "lan")
t.Run("A", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion(hostname+".lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers for %v: got %d, want %d", m.Question, got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.A); !ok {
t.Fatalf("unexpected response type: got %T, want dns.A", a)
}
if got, want := a.(*dns.A).A, net.ParseIP("127.0.0.2"); !got.Equal(want) {
t.Fatalf("unexpected response IP: got %v, want %v", got, want)
}
})
t.Run("PTR", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("2.0.0.127.in-addr.arpa.", dns.TypePTR)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers: got %d, want %d", got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.PTR); !ok {
t.Fatalf("unexpected response type: got %T, want dns.PTR", a)
}
if got, want := a.(*dns.PTR).Ptr, hostname+".lan."; got != want {
t.Fatalf("unexpected response record: got %q, want %q", got, want)
}
})
t.Run("AAAA", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion(hostname+".lan.", dns.TypeAAAA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.MsgHdr.Rcode, dns.RcodeSuccess; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
if got, want := len(r.response.Answer), 0; got != want {
t.Fatalf("unexpected number of answers: got %d, want %d", got, want)
}
})
}
func TestLocalhost(t *testing.T) {
r := &recorder{}
s := NewServer("127.0.0.2:0", "lan")
t.Run("A", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("localhost.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers for %v: got %d, want %d", m.Question, got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.A); !ok {
t.Fatalf("unexpected response type: got %T, want dns.A", a)
}
if got, want := a.(*dns.A).A, net.ParseIP("127.0.0.1"); !got.Equal(want) {
t.Fatalf("unexpected response IP: got %v, want %v", got, want)
}
})
t.Run("AAAA", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("localhost.", dns.TypeAAAA)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers for %v: got %d, want %d", m.Question, got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.AAAA); !ok {
t.Fatalf("unexpected response type: got %T, want dns.A", a)
}
if got, want := a.(*dns.AAAA).AAAA, (net.ParseIP("::1")); !got.Equal(want) {
t.Fatalf("unexpected response IP: got %v, want %v", got, want)
}
})
t.Run("PTR", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("1.0.0.127.in-addr.arpa.", dns.TypePTR)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers: got %d, want %d", got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.PTR); !ok {
t.Fatalf("unexpected response type: got %T, want dns.PTR", a)
}
if got, want := a.(*dns.PTR).Ptr, "localhost."; got != want {
t.Fatalf("unexpected response record: got %q, want %q", got, want)
}
})
}
func TestDHCPReverse(t *testing.T) {
for _, test := range []struct {
ip net.IP
question string
}{
{
ip: net.IP{192, 168, 42, 23},
question: "23.42.168.192.in-addr.arpa.",
},
{
ip: net.IP{10, 0, 0, 2},
question: "2.0.0.10.in-addr.arpa.",
},
{
ip: net.IP{172, 16, 0, 1}, // 172.16/12 HostMin
question: "1.0.16.172.in-addr.arpa.",
},
{
ip: net.IP{172, 31, 255, 254}, // 172.16/12 HostMax
question: "254.255.31.172.in-addr.arpa.",
},
} {
t.Run(test.question, func(t *testing.T) {
r := &recorder{}
s := NewServer("localhost:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: test.ip,
},
})
m := new(dns.Msg)
m.SetQuestion(test.question, dns.TypePTR)
s.Mux.ServeDNS(r, m)
if got, want := len(r.response.Answer), 1; got != want {
t.Fatalf("unexpected number of answers: got %d, want %d", got, want)
}
a := r.response.Answer[0]
if _, ok := a.(*dns.PTR); !ok {
t.Fatalf("unexpected response type: got %T, want dns.PTR", a)
}
if got, want := a.(*dns.PTR).Ptr, "testtarget.lan."; got != want {
t.Fatalf("unexpected response record: got %q, want %q", got, want)
}
})
}
t.Run("no leases", func(t *testing.T) {
r := &recorder{}
s := NewServer("localhost:0", "lan")
m := new(dns.Msg)
m.SetQuestion("254.255.31.172.in-addr.arpa.", dns.TypePTR)
s.Mux.ServeDNS(r, m)
if got, want := r.response.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
})
}
func resolveTestTarget(s *Server, name string, want net.IP) error {
m := new(dns.Msg)
typ := dns.TypeA
if want.To4() == nil {
typ = dns.TypeAAAA
}
m.SetQuestion(name, typ)
r := &recorder{}
s.Mux.ServeDNS(r, m)
if r.response == nil {
return fmt.Errorf("nil response")
}
if got, want := len(r.response.Answer), 1; got != want {
return fmt.Errorf("unexpected number of answers: got %d, want %d", got, want)
}
a := r.response.Answer[0]
if typ == dns.TypeA {
if _, ok := a.(*dns.A); !ok {
return fmt.Errorf("unexpected response type: got %T, want dns.A", a)
}
if got := a.(*dns.A).A; !got.Equal(want) {
return fmt.Errorf("unexpected response IP: got %v, want %v", got, want)
}
} else {
if _, ok := a.(*dns.AAAA); !ok {
return fmt.Errorf("unexpected response type: got %T, want dns.A", a)
}
if got := a.(*dns.AAAA).AAAA; !got.Equal(want) {
return fmt.Errorf("unexpected response IP: got %v, want %v", got, want)
}
}
return nil
}
// TODO: multiple questions
func TestUppercase(t *testing.T) {
s := NewServer("127.0.0.2:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "UPPERCASE",
Addr: net.IP{192, 168, 42, 23},
},
})
for _, casing := range []string{
"UPPERCASE",
"uppercase",
"upperCase",
} {
if err := resolveTestTarget(s, casing+".lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
}
}
func TestSubname(t *testing.T) {
r := &recorder{}
s := NewServer("127.0.0.2:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
},
})
t.Run("testtarget.lan.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("192.168.42.23")); err != nil {
t.Fatal(err)
}
})
t.Run("sub.testtarget.lan.", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("notfound.lan.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
})
setSubname := func(host, ip, remoteAddr string) {
val := url.Values{
"host": []string{host},
"ip": []string{ip},
}
req := httptest.NewRequest("POST", "/dyndns", strings.NewReader(val.Encode()))
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
req.RemoteAddr = remoteAddr
rec := httptest.NewRecorder()
s.DyndnsHandler(rec, req)
resp := rec.Result()
if got, want := resp.StatusCode, http.StatusOK; got != want {
body, _ := ioutil.ReadAll(resp.Body)
t.Fatalf("POST /dyndns: unexpected HTTP status: got %v, want %v (%q)", resp.Status, want, string(body))
}
}
const ip = "fdf5:3606:2a21:1341:b26e:bfff:fe30:504b"
setSubname("sub.testtarget", ip, "192.168.42.23:1234")
for _, name := range []string{
"sub.testtarget.lan.",
"sub.testtarget.",
} {
t.Run(name+" (after dyndns)", func(t *testing.T) {
if err := resolveTestTarget(s, name, net.ParseIP(ip)); err != nil {
t.Fatal(err)
}
})
}
t.Run("Hostname", func(t *testing.T) {
hostname, err := os.Hostname()
if err != nil {
t.Skipf("os.Hostname: %v", err)
}
if err := resolveTestTarget(s, hostname+".lan.", net.ParseIP("127.0.0.2")); err != nil {
t.Fatal(err)
}
setSubname("sub.turin", ip, "127.0.0.2:1234")
if err := resolveTestTarget(s, "sub."+hostname+".lan.", net.ParseIP(ip)); err != nil {
t.Fatal(err)
}
})
}
func TestDNSEntries(t *testing.T) {
r := &recorder{}
s := NewServer("127.0.0.2:0", "lan")
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
},
{
Hostname: "testtarget-ipv6",
Addr: net.ParseIP("fe80:3::"),
},
})
s.SetDNSEntries([]IP{
IP{
Host: "testtarget",
IPv4: net.IP{7, 7, 7, 7},
IPv6: net.ParseIP("fe80:1::"),
},
IP{
Host: "testtarget.example.org",
IPv4: net.IP{8, 8, 8, 8},
IPv6: net.ParseIP("fe80:2::"),
},
{
Host: "testtarget-ipv6",
IPv4: net.IP{9, 9, 9, 9},
IPv6: net.ParseIP("fe80:9::"),
},
})
t.Run("testtarget.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.", net.IP{192, 168, 42, 23}); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget.lan.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.IP{192, 168, 42, 23}); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget-ipv6.lan. (IPv6)", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget-ipv6.lan.", net.ParseIP("fe80:3::")); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget-ipv6.lan. (no override???)", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget-ipv6.lan.", net.IP{9, 9, 9, 9}); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget.lan. (IPv6) (no override???)", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.lan.", net.ParseIP("fe80:1::")); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget.example.org.", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.example.org.", net.IP{8, 8, 8, 8}); err != nil {
t.Fatal(err)
}
})
t.Run("testtarget.example.org. (IPv6)", func(t *testing.T) {
if err := resolveTestTarget(s, "testtarget.example.org.", net.ParseIP("fe80:2::")); err != nil {
t.Fatal(err)
}
})
s.SetLeases([]dhcp4d.Lease{
{
Hostname: "testtarget",
Addr: net.IP{192, 168, 42, 23},
},
})
t.Run("testtarget.example.org. (deleted)", func(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("testtarget.example.org.", dns.TypeA)
s.Mux.ServeDNS(r, m)
if got, want := r.response.Rcode, dns.RcodeNameError; got != want {
t.Fatalf("unexpected rcode: got %v, want %v", got, want)
}
})
}