server_test.go

package dns

import (
	"crypto/tls"
	"fmt"
	"io"
	"net"
	"runtime"
	"sync"
	"testing"
	"time"
)

func HelloServer(w ResponseWriter, req *Msg) {
	m := new(Msg)
	m.SetReply(req)

	m.Extra = make([]RR, 1)
	m.Extra[0] = &TXT{Hdr: RR_Header{Name: m.Question[0].Name, Rrtype: TypeTXT, Class: ClassINET, Ttl: 0}, Txt: []string{"Hello world"}}
	w.WriteMsg(m)
}

func HelloServerBadID(w ResponseWriter, req *Msg) {
	m := new(Msg)
	m.SetReply(req)
	m.Id++

	m.Extra = make([]RR, 1)
	m.Extra[0] = &TXT{Hdr: RR_Header{Name: m.Question[0].Name, Rrtype: TypeTXT, Class: ClassINET, Ttl: 0}, Txt: []string{"Hello world"}}
	w.WriteMsg(m)
}

func AnotherHelloServer(w ResponseWriter, req *Msg) {
	m := new(Msg)
	m.SetReply(req)

	m.Extra = make([]RR, 1)
	m.Extra[0] = &TXT{Hdr: RR_Header{Name: m.Question[0].Name, Rrtype: TypeTXT, Class: ClassINET, Ttl: 0}, Txt: []string{"Hello example"}}
	w.WriteMsg(m)
}

func RunLocalUDPServer(laddr string) (*Server, string, error) {
	server, l, _, err := RunLocalUDPServerWithFinChan(laddr)

	return server, l, err
}

func RunLocalUDPServerWithFinChan(laddr string) (*Server, string, chan struct{}, error) {
	pc, err := net.ListenPacket("udp", laddr)
	if err != nil {
		return nil, "", nil, err
	}
	server := &Server{PacketConn: pc, ReadTimeout: time.Hour, WriteTimeout: time.Hour}

	waitLock := sync.Mutex{}
	waitLock.Lock()
	server.NotifyStartedFunc = waitLock.Unlock

	fin := make(chan struct{}, 0)

	go func() {
		server.ActivateAndServe()
		close(fin)
		pc.Close()
	}()

	waitLock.Lock()
	return server, pc.LocalAddr().String(), fin, nil
}

func RunLocalUDPServerUnsafe(laddr string) (*Server, string, error) {
	pc, err := net.ListenPacket("udp", laddr)
	if err != nil {
		return nil, "", err
	}
	server := &Server{PacketConn: pc, Unsafe: true,
		ReadTimeout: time.Hour, WriteTimeout: time.Hour}

	waitLock := sync.Mutex{}
	waitLock.Lock()
	server.NotifyStartedFunc = waitLock.Unlock

	go func() {
		server.ActivateAndServe()
		pc.Close()
	}()

	waitLock.Lock()
	return server, pc.LocalAddr().String(), nil
}

func RunLocalTCPServer(laddr string) (*Server, string, error) {
	l, err := net.Listen("tcp", laddr)
	if err != nil {
		return nil, "", err
	}

	server := &Server{Listener: l, ReadTimeout: time.Hour, WriteTimeout: time.Hour}

	waitLock := sync.Mutex{}
	waitLock.Lock()
	server.NotifyStartedFunc = waitLock.Unlock

	go func() {
		server.ActivateAndServe()
		l.Close()
	}()

	waitLock.Lock()
	return server, l.Addr().String(), nil
}

func RunLocalTLSServer(laddr string, config *tls.Config) (*Server, string, error) {
	l, err := tls.Listen("tcp", laddr, config)
	if err != nil {
		return nil, "", err
	}

	server := &Server{Listener: l, ReadTimeout: time.Hour, WriteTimeout: time.Hour}

	waitLock := sync.Mutex{}
	waitLock.Lock()
	server.NotifyStartedFunc = waitLock.Unlock

	go func() {
		server.ActivateAndServe()
		l.Close()
	}()

	waitLock.Lock()
	return server, l.Addr().String(), nil
}

func TestServing(t *testing.T) {
	HandleFunc("miek.nl.", HelloServer)
	HandleFunc("example.com.", AnotherHelloServer)
	defer HandleRemove("miek.nl.")
	defer HandleRemove("example.com.")

	s, addrstr, err := RunLocalUDPServer("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl.", TypeTXT)
	r, _, err := c.Exchange(m, addrstr)
	if err != nil || len(r.Extra) == 0 {
		t.Fatal("failed to exchange miek.nl", err)
	}
	txt := r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello world" {
		t.Error("unexpected result for miek.nl", txt, "!= Hello world")
	}

	m.SetQuestion("example.com.", TypeTXT)
	r, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Fatal("failed to exchange example.com", err)
	}
	txt = r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello example" {
		t.Error("unexpected result for example.com", txt, "!= Hello example")
	}

	// Test Mixes cased as noticed by Ask.
	m.SetQuestion("eXaMplE.cOm.", TypeTXT)
	r, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Error("failed to exchange eXaMplE.cOm", err)
	}
	txt = r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello example" {
		t.Error("unexpected result for example.com", txt, "!= Hello example")
	}
}

func TestServingTLS(t *testing.T) {
	HandleFunc("miek.nl.", HelloServer)
	HandleFunc("example.com.", AnotherHelloServer)
	defer HandleRemove("miek.nl.")
	defer HandleRemove("example.com.")

	cert, err := tls.X509KeyPair(CertPEMBlock, KeyPEMBlock)
	if err != nil {
		t.Fatalf("unable to build certificate: %v", err)
	}

	config := tls.Config{
		Certificates: []tls.Certificate{cert},
	}

	s, addrstr, err := RunLocalTLSServer("127.0.0.1:0", &config)
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	c := new(Client)
	c.Net = "tcp-tls"
	c.TLSConfig = &tls.Config{
		InsecureSkipVerify: true,
	}

	m := new(Msg)
	m.SetQuestion("miek.nl.", TypeTXT)
	r, _, err := c.Exchange(m, addrstr)
	if err != nil || len(r.Extra) == 0 {
		t.Fatal("failed to exchange miek.nl", err)
	}
	txt := r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello world" {
		t.Error("unexpected result for miek.nl", txt, "!= Hello world")
	}

	m.SetQuestion("example.com.", TypeTXT)
	r, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Fatal("failed to exchange example.com", err)
	}
	txt = r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello example" {
		t.Error("unexpected result for example.com", txt, "!= Hello example")
	}

	// Test Mixes cased as noticed by Ask.
	m.SetQuestion("eXaMplE.cOm.", TypeTXT)
	r, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Error("failed to exchange eXaMplE.cOm", err)
	}
	txt = r.Extra[0].(*TXT).Txt[0]
	if txt != "Hello example" {
		t.Error("unexpected result for example.com", txt, "!= Hello example")
	}
}

func BenchmarkServe(b *testing.B) {
	b.StopTimer()
	HandleFunc("miek.nl.", HelloServer)
	defer HandleRemove("miek.nl.")
	a := runtime.GOMAXPROCS(4)

	s, addrstr, err := RunLocalUDPServer("127.0.0.1:0")
	if err != nil {
		b.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl", TypeSOA)

	b.StartTimer()
	for i := 0; i < b.N; i++ {
		c.Exchange(m, addrstr)
	}
	runtime.GOMAXPROCS(a)
}

func benchmarkServe6(b *testing.B) {
	b.StopTimer()
	HandleFunc("miek.nl.", HelloServer)
	defer HandleRemove("miek.nl.")
	a := runtime.GOMAXPROCS(4)
	s, addrstr, err := RunLocalUDPServer("[::1]:0")
	if err != nil {
		b.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl", TypeSOA)

	b.StartTimer()
	for i := 0; i < b.N; i++ {
		c.Exchange(m, addrstr)
	}
	runtime.GOMAXPROCS(a)
}

func HelloServerCompress(w ResponseWriter, req *Msg) {
	m := new(Msg)
	m.SetReply(req)
	m.Extra = make([]RR, 1)
	m.Extra[0] = &TXT{Hdr: RR_Header{Name: m.Question[0].Name, Rrtype: TypeTXT, Class: ClassINET, Ttl: 0}, Txt: []string{"Hello world"}}
	m.Compress = true
	w.WriteMsg(m)
}

func BenchmarkServeCompress(b *testing.B) {
	b.StopTimer()
	HandleFunc("miek.nl.", HelloServerCompress)
	defer HandleRemove("miek.nl.")
	a := runtime.GOMAXPROCS(4)
	s, addrstr, err := RunLocalUDPServer("127.0.0.1:0")
	if err != nil {
		b.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl", TypeSOA)
	b.StartTimer()
	for i := 0; i < b.N; i++ {
		c.Exchange(m, addrstr)
	}
	runtime.GOMAXPROCS(a)
}

func TestDotAsCatchAllWildcard(t *testing.T) {
	mux := NewServeMux()
	mux.Handle(".", HandlerFunc(HelloServer))
	mux.Handle("example.com.", HandlerFunc(AnotherHelloServer))

	handler := mux.match("www.miek.nl.", TypeTXT)
	if handler == nil {
		t.Error("wildcard match failed")
	}

	handler = mux.match("www.example.com.", TypeTXT)
	if handler == nil {
		t.Error("example.com match failed")
	}

	handler = mux.match("a.www.example.com.", TypeTXT)
	if handler == nil {
		t.Error("a.www.example.com match failed")
	}

	handler = mux.match("boe.", TypeTXT)
	if handler == nil {
		t.Error("boe. match failed")
	}
}

func TestCaseFolding(t *testing.T) {
	mux := NewServeMux()
	mux.Handle("_udp.example.com.", HandlerFunc(HelloServer))

	handler := mux.match("_dns._udp.example.com.", TypeSRV)
	if handler == nil {
		t.Error("case sensitive characters folded")
	}

	handler = mux.match("_DNS._UDP.EXAMPLE.COM.", TypeSRV)
	if handler == nil {
		t.Error("case insensitive characters not folded")
	}
}

func TestRootServer(t *testing.T) {
	mux := NewServeMux()
	mux.Handle(".", HandlerFunc(HelloServer))

	handler := mux.match(".", TypeNS)
	if handler == nil {
		t.Error("root match failed")
	}
}

type maxRec struct {
	max int
	sync.RWMutex
}

var M = new(maxRec)

func HelloServerLargeResponse(resp ResponseWriter, req *Msg) {
	m := new(Msg)
	m.SetReply(req)
	m.Authoritative = true
	m1 := 0
	M.RLock()
	m1 = M.max
	M.RUnlock()
	for i := 0; i < m1; i++ {
		aRec := &A{
			Hdr: RR_Header{
				Name:   req.Question[0].Name,
				Rrtype: TypeA,
				Class:  ClassINET,
				Ttl:    0,
			},
			A: net.ParseIP(fmt.Sprintf("127.0.0.%d", i+1)).To4(),
		}
		m.Answer = append(m.Answer, aRec)
	}
	resp.WriteMsg(m)
}

func TestServingLargeResponses(t *testing.T) {
	HandleFunc("example.", HelloServerLargeResponse)
	defer HandleRemove("example.")

	s, addrstr, err := RunLocalUDPServer("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	// Create request
	m := new(Msg)
	m.SetQuestion("web.service.example.", TypeANY)

	c := new(Client)
	c.Net = "udp"
	M.Lock()
	M.max = 2
	M.Unlock()
	_, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Errorf("failed to exchange: %v", err)
	}
	// This must fail
	M.Lock()
	M.max = 20
	M.Unlock()
	_, _, err = c.Exchange(m, addrstr)
	if err == nil {
		t.Error("failed to fail exchange, this should generate packet error")
	}
	// But this must work again
	c.UDPSize = 7000
	_, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Errorf("failed to exchange: %v", err)
	}
}

func TestServingResponse(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}
	HandleFunc("miek.nl.", HelloServer)
	s, addrstr, err := RunLocalUDPServer("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl.", TypeTXT)
	m.Response = false
	_, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Fatal("failed to exchange", err)
	}
	m.Response = true
	_, _, err = c.Exchange(m, addrstr)
	if err == nil {
		t.Fatal("exchanged response message")
	}

	s.Shutdown()
	s, addrstr, err = RunLocalUDPServerUnsafe("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	defer s.Shutdown()

	m.Response = true
	_, _, err = c.Exchange(m, addrstr)
	if err != nil {
		t.Fatal("could exchanged response message in Unsafe mode")
	}
}

func TestShutdownTCP(t *testing.T) {
	s, _, err := RunLocalTCPServer("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	err = s.Shutdown()
	if err != nil {
		t.Errorf("could not shutdown test TCP server, %v", err)
	}
}

func TestShutdownTLS(t *testing.T) {
	cert, err := tls.X509KeyPair(CertPEMBlock, KeyPEMBlock)
	if err != nil {
		t.Fatalf("unable to build certificate: %v", err)
	}

	config := tls.Config{
		Certificates: []tls.Certificate{cert},
	}

	s, _, err := RunLocalTLSServer("127.0.0.1:0", &config)
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	err = s.Shutdown()
	if err != nil {
		t.Errorf("could not shutdown test TLS server, %v", err)
	}
}

type trigger struct {
	done bool
	sync.RWMutex
}

func (t *trigger) Set() {
	t.Lock()
	defer t.Unlock()
	t.done = true
}
func (t *trigger) Get() bool {
	t.RLock()
	defer t.RUnlock()
	return t.done
}

func TestHandlerCloseTCP(t *testing.T) {

	ln, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		panic(err)
	}
	addr := ln.Addr().String()

	server := &Server{Addr: addr, Net: "tcp", Listener: ln}

	hname := "testhandlerclosetcp."
	triggered := &trigger{}
	HandleFunc(hname, func(w ResponseWriter, r *Msg) {
		triggered.Set()
		w.Close()
	})
	defer HandleRemove(hname)

	go func() {
		defer server.Shutdown()
		c := &Client{Net: "tcp"}
		m := new(Msg).SetQuestion(hname, 1)
		tries := 0
	exchange:
		_, _, err := c.Exchange(m, addr)
		if err != nil && err != io.EOF {
			t.Logf("exchange failed: %s\n", err)
			if tries == 3 {
				return
			}
			time.Sleep(time.Second / 10)
			tries++
			goto exchange
		}
	}()
	server.ActivateAndServe()
	if !triggered.Get() {
		t.Fatalf("handler never called")
	}
}

func TestShutdownUDP(t *testing.T) {
	s, _, fin, err := RunLocalUDPServerWithFinChan("127.0.0.1:0")
	if err != nil {
		t.Fatalf("unable to run test server: %v", err)
	}
	err = s.Shutdown()
	if err != nil {
		t.Errorf("could not shutdown test UDP server, %v", err)
	}
	select {
	case <-fin:
	case <-time.After(2 * time.Second):
		t.Error("Could not shutdown test UDP server. Gave up waiting")
	}
}

type ExampleFrameLengthWriter struct {
	Writer
}

func (e *ExampleFrameLengthWriter) Write(m []byte) (int, error) {
	fmt.Println("writing raw DNS message of length", len(m))
	return e.Writer.Write(m)
}

func ExampleDecorateWriter() {
	// instrument raw DNS message writing
	wf := DecorateWriter(func(w Writer) Writer {
		return &ExampleFrameLengthWriter{w}
	})

	// simple UDP server
	pc, err := net.ListenPacket("udp", "127.0.0.1:0")
	if err != nil {
		fmt.Println(err.Error())
		return
	}
	server := &Server{
		PacketConn:     pc,
		DecorateWriter: wf,
		ReadTimeout:    time.Hour, WriteTimeout: time.Hour,
	}

	waitLock := sync.Mutex{}
	waitLock.Lock()
	server.NotifyStartedFunc = waitLock.Unlock
	defer server.Shutdown()

	go func() {
		server.ActivateAndServe()
		pc.Close()
	}()

	waitLock.Lock()

	HandleFunc("miek.nl.", HelloServer)

	c := new(Client)
	m := new(Msg)
	m.SetQuestion("miek.nl.", TypeTXT)
	_, _, err = c.Exchange(m, pc.LocalAddr().String())
	if err != nil {
		fmt.Println("failed to exchange", err.Error())
		return
	}
	// Output: writing raw DNS message of length 56
}

var (
	// CertPEMBlock is a X509 data used to test TLS servers (used with tls.X509KeyPair)
	CertPEMBlock = []byte(`-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----`)

	// KeyPEMBlock is a X509 data used to test TLS servers (used with tls.X509KeyPair)
	KeyPEMBlock = []byte(`-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----`)
)

func testShutdownBindPort(t *testing.T, protocol string, port string) {
	handler := NewServeMux()
	handler.HandleFunc(".", func(w ResponseWriter, r *Msg) {})
	startedCh := make(chan struct{})
	s := &Server{
		Addr:    net.JoinHostPort("127.0.0.1", port),
		Net:     protocol,
		Handler: handler,
		NotifyStartedFunc: func() {
			startedCh <- struct{}{}
		},
	}
	go func() {
		if err := s.ListenAndServe(); err != nil {
			t.Log(err)
		}
	}()
	<-startedCh
	t.Logf("DNS server is started on: %s", s.Addr)
	if err := s.Shutdown(); err != nil {
		t.Fatal(err)
	}
	time.Sleep(100 * time.Millisecond)
	go func() {
		if err := s.ListenAndServe(); err != nil {
			t.Fatal(err)
		}
	}()
	<-startedCh
	t.Logf("DNS server is started on: %s", s.Addr)
}

func TestShutdownBindPortUDP(t *testing.T) {
	testShutdownBindPort(t, "udp", "1153")
}

func TestShutdownBindPortTCP(t *testing.T) {
	testShutdownBindPort(t, "tcp", "1154")
}