Example #1
0
func TestDNS_CaseInsensitiveNodeLookup(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "Foo",
		Address:    "127.0.0.1",
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("fOO.node.dc1.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 1 {
		t.Fatalf("empty lookup: %#v", in)
	}
}
Example #2
0
func TestDNS_ServiceLookup_TagPeriod(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "foo",
		Address:    "127.0.0.1",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"v1.master"},
			Port:    12345,
		},
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("v1.master.db.service.consul.", dns.TypeSRV)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 1 {
		t.Fatalf("Bad: %#v", in)
	}

	srvRec, ok := in.Answer[0].(*dns.SRV)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if srvRec.Port != 12345 {
		t.Fatalf("Bad: %#v", srvRec)
	}
	if srvRec.Target != "foo.node.dc1.consul." {
		t.Fatalf("Bad: %#v", srvRec)
	}

	aRec, ok := in.Extra[0].(*dns.A)
	if !ok {
		t.Fatalf("Bad: %#v", in.Extra[0])
	}
	if aRec.Hdr.Name != "foo.node.dc1.consul." {
		t.Fatalf("Bad: %#v", in.Extra[0])
	}
	if aRec.A.String() != "127.0.0.1" {
		t.Fatalf("Bad: %#v", in.Extra[0])
	}
}
Example #3
0
func TestDNS_IsAlive(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	m := new(dns.Msg)
	m.SetQuestion("_test.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 1 {
		t.Fatalf("Bad: %#v", in)
	}

	txt, ok := in.Answer[0].(*dns.TXT)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if txt.Txt[0] != "ok" {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
}
Example #4
0
func (s *server) unregister() error {
	resp := new(dns.Msg)
	resp.Answer = []dns.RR{}
	resp.Extra = []dns.RR{}
	s.composeLookupAnswers(resp, 0)
	return s.multicastResponse(resp)
}
Example #5
0
func ExamplePrivateHandle() {
	dns.PrivateHandle("APAIR", TypeAPAIR, NewAPAIR)
	defer dns.PrivateHandleRemove(TypeAPAIR)

	rr, err := dns.NewRR("miek.nl. APAIR (1.2.3.4    1.2.3.5)")
	if err != nil {
		log.Fatal("could not parse APAIR record: ", err)
	}
	fmt.Println(rr)
	// Output: miek.nl.	3600	IN	APAIR	1.2.3.4 1.2.3.5

	m := new(dns.Msg)
	m.Id = 12345
	m.SetQuestion("miek.nl.", TypeAPAIR)
	m.Answer = append(m.Answer, rr)

	fmt.Println(m)
	// ;; opcode: QUERY, status: NOERROR, id: 12345
	// ;; flags: rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
	//
	// ;; QUESTION SECTION:
	// ;miek.nl.	IN	 APAIR
	//
	// ;; ANSWER SECTION:
	// miek.nl.	3600	IN	APAIR	1.2.3.4 1.2.3.5
}
Example #6
0
func (s *server) composeBrowsingAnswers(resp *dns.Msg, ttl uint32) {
	ptr := &dns.PTR{
		Hdr: dns.RR_Header{
			Name:   s.service.ServiceName(),
			Rrtype: dns.TypePTR,
			Class:  dns.ClassINET,
			Ttl:    ttl,
		},
		Ptr: s.service.ServiceInstanceName(),
	}
	resp.Answer = append(resp.Answer, ptr)

	txt := &dns.TXT{
		Hdr: dns.RR_Header{
			Name:   s.service.ServiceInstanceName(),
			Rrtype: dns.TypeTXT,
			Class:  dns.ClassINET,
			Ttl:    ttl,
		},
		Txt: s.service.Text,
	}
	srv := &dns.SRV{
		Hdr: dns.RR_Header{
			Name:   s.service.ServiceInstanceName(),
			Rrtype: dns.TypeSRV,
			Class:  dns.ClassINET,
			Ttl:    ttl,
		},
		Priority: 0,
		Weight:   0,
		Port:     uint16(s.service.Port),
		Target:   s.service.HostName,
	}
	resp.Extra = append(resp.Extra, srv, txt)

	if s.service.AddrIPv4 != nil {
		a := &dns.A{
			Hdr: dns.RR_Header{
				Name:   s.service.HostName,
				Rrtype: dns.TypeA,
				Class:  dns.ClassINET,
				Ttl:    ttl,
			},
			A: s.service.AddrIPv4,
		}
		resp.Extra = append(resp.Extra, a)
	}
	if s.service.AddrIPv6 != nil {
		aaaa := &dns.AAAA{
			Hdr: dns.RR_Header{
				Name:   s.service.HostName,
				Rrtype: dns.TypeAAAA,
				Class:  dns.ClassINET,
				Ttl:    ttl,
			},
			AAAA: s.service.AddrIPv6,
		}
		resp.Extra = append(resp.Extra, aaaa)
	}
}
Example #7
0
// resolveCNAME is used to recursively resolve CNAME records
func (d *DNSServer) resolveCNAME(name string) []dns.RR {
	// Do nothing if we don't have a recursor
	if len(d.recursors) == 0 {
		return nil
	}

	// Ask for any A records
	m := new(dns.Msg)
	m.SetQuestion(name, dns.TypeA)

	// Make a DNS lookup request
	c := &dns.Client{Net: "udp"}
	var r *dns.Msg
	var rtt time.Duration
	var err error
	for _, recursor := range d.recursors {
		r, rtt, err = c.Exchange(m, recursor)
		if err == nil {
			d.logger.Printf("[DEBUG] dns: cname recurse RTT for %v (%v)", name, rtt)
			return r.Answer
		}
		d.logger.Printf("[ERR] dns: cname recurse failed for %v: %v", name, err)
	}
	d.logger.Printf("[ERR] dns: all resolvers failed for %v", name)
	return nil
}
Example #8
0
// parsePacket is used to parse an incoming packet
func (s *server) parsePacket(packet []byte, from net.Addr) error {
	var msg dns.Msg
	if err := msg.Unpack(packet); err != nil {
		log.Printf("[ERR] bonjour: Failed to unpack packet: %v", err)
		return err
	}
	return s.handleQuery(&msg, from)
}
Example #9
0
func TestDNS_ServiceLookup_CNAME(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "google",
		Address:    "www.google.com",
		Service: &structs.NodeService{
			Service: "search",
			Port:    80,
		},
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("search.service.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 4 {
		t.Fatalf("Bad: %#v", in)
	}

	// Should have google CNAME
	cnRec, ok := in.Answer[0].(*dns.CNAME)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if cnRec.Target != "www.google.com." {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}

	// Check we recursively resolve
	for i := 1; i < 4; i++ {
		if _, ok := in.Answer[i].(*dns.A); !ok {
			t.Fatalf("Bad: %#v", in.Answer[i])
		}
	}
}
Example #10
0
// Pack the dns.Msg and write to available connections (multicast)
func (c *client) sendQuery(msg *dns.Msg) error {
	buf, err := msg.Pack()
	if err != nil {
		return err
	}
	if c.ipv4conn != nil {
		c.ipv4conn.WriteTo(buf, ipv4Addr)
	}
	if c.ipv4conn != nil {
		c.ipv4conn.WriteTo(buf, ipv6Addr)
	}
	return nil
}
Example #11
0
// multicastResponse us used to send a multicast response packet
func (c *server) multicastResponse(msg *dns.Msg) error {
	buf, err := msg.Pack()
	if err != nil {
		log.Println("Failed to pack message!")
		return err
	}
	if c.ipv4conn != nil {
		c.ipv4conn.WriteTo(buf, ipv4Addr)
	}
	if c.ipv6conn != nil {
		c.ipv6conn.WriteTo(buf, ipv6Addr)
	}
	return nil
}
Example #12
0
// sendResponse is used to send a unicast response packet
func (s *server) sendResponse(resp *dns.Msg, from net.Addr) error {
	buf, err := resp.Pack()
	if err != nil {
		return err
	}
	addr := from.(*net.UDPAddr)
	if addr.IP.To4() != nil {
		_, err = s.ipv4conn.WriteToUDP(buf, addr)
		return err
	} else {
		_, err = s.ipv6conn.WriteToUDP(buf, addr)
		return err
	}
}
Example #13
0
func TestDNS_NodeLookup_CNAME(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "google",
		Address:    "www.google.com",
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("google.node.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	// Should have the CNAME record + a few A records
	if len(in.Answer) < 2 {
		t.Fatalf("Bad: %#v", in)
	}

	cnRec, ok := in.Answer[0].(*dns.CNAME)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if cnRec.Target != "www.google.com." {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if cnRec.Hdr.Ttl != 0 {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
}
Example #14
0
func TestDNS_NodeLookup_AAAA(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "bar",
		Address:    "::4242:4242",
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("bar.node.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 1 {
		t.Fatalf("Bad: %#v", in)
	}

	aRec, ok := in.Answer[0].(*dns.AAAA)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if aRec.AAAA.String() != "::4242:4242" {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if aRec.Hdr.Ttl != 0 {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
}
Example #15
0
// Retrieve the MX records for miek.nl.
func ExampleMX() {
	config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
	c := new(dns.Client)
	m := new(dns.Msg)
	m.SetQuestion("miek.nl.", dns.TypeMX)
	m.RecursionDesired = true
	r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
	if err != nil {
		return
	}
	if r.Rcode != dns.RcodeSuccess {
		return
	}
	for _, a := range r.Answer {
		if mx, ok := a.(*dns.MX); ok {
			fmt.Printf("%s\n", mx.String())
		}
	}
}
Example #16
0
func TestDNS_ReverseLookup_CustomDomain(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()
	srv.domain = dns.Fqdn("custom")

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register node
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "foo2",
		Address:    "127.0.0.2",
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("2.0.0.127.in-addr.arpa.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) != 1 {
		t.Fatalf("Bad: %#v", in)
	}

	ptrRec, ok := in.Answer[0].(*dns.PTR)
	if !ok {
		t.Fatalf("Bad: %#v", in.Answer[0])
	}
	if ptrRec.Ptr != "foo2.node.dc1.custom." {
		t.Fatalf("Bad: %#v", ptrRec)
	}
}
Example #17
0
// handleQuery is used to handle an incoming query
func (s *server) handleQuery(query *dns.Msg, from net.Addr) error {
	// Ignore answer for now
	if len(query.Answer) > 0 {
		return nil
	}
	// Ignore questions with Authorative section for now
	if len(query.Ns) > 0 {
		return nil
	}

	// Handle each question
	var (
		resp dns.Msg
		err  error
	)
	if len(query.Question) > 0 {
		for i, _ := range query.Question {
			resp = dns.Msg{}
			resp.SetReply(query)
			resp.Answer = []dns.RR{}
			resp.Extra = []dns.RR{}
			if err = s.handleQuestion(query.Question[i], &resp); err != nil {
				log.Printf("[ERR] bonjour: failed to handle question %v: %v",
					query.Question[i], err)
				continue
			}
			// Check if there is an answer
			if len(resp.Answer) > 0 {
				//return s.sendResponse(&resp, from)
				//log.Println("====== BEGIN ======")
				//log.Println(resp.String())
				//log.Println("======= END =======")
				if e := s.multicastResponse(&resp); e != nil {
					err = e
				}
			}
		}
	}

	return err
}
Example #18
0
// nodeLookup is used to handle a node query
func (d *DNSServer) nodeLookup(network, datacenter, node string, req, resp *dns.Msg) {
	// Only handle ANY and A type requests
	qType := req.Question[0].Qtype
	if qType != dns.TypeANY && qType != dns.TypeA {
		return
	}

	// Make an RPC request
	args := structs.NodeSpecificRequest{
		Datacenter:   datacenter,
		Node:         node,
		QueryOptions: structs.QueryOptions{AllowStale: d.config.AllowStale},
	}
	var out structs.IndexedNodeServices
RPC:
	if err := d.agent.RPC("Catalog.NodeServices", &args, &out); err != nil {
		d.logger.Printf("[ERR] dns: rpc error: %v", err)
		resp.SetRcode(req, dns.RcodeServerFailure)
		return
	}

	// Verify that request is not too stale, redo the request
	if args.AllowStale && out.LastContact > d.config.MaxStale {
		args.AllowStale = false
		d.logger.Printf("[WARN] dns: Query results too stale, re-requesting")
		goto RPC
	}

	// If we have no address, return not found!
	if out.NodeServices == nil {
		resp.SetRcode(req, dns.RcodeNameError)
		return
	}

	// Add the node record
	records := d.formatNodeRecord(&out.NodeServices.Node, out.NodeServices.Node.Address,
		req.Question[0].Name, qType, d.config.NodeTTL)
	if records != nil {
		resp.Answer = append(resp.Answer, records...)
	}
}
Example #19
0
// handleTest is used to handle DNS queries in the ".consul." domain
func (d *DNSServer) handleTest(resp dns.ResponseWriter, req *dns.Msg) {
	q := req.Question[0]
	defer func(s time.Time) {
		d.logger.Printf("[DEBUG] dns: request for %v (%v)", q, time.Now().Sub(s))
	}(time.Now())

	if !(q.Qtype == dns.TypeANY || q.Qtype == dns.TypeTXT) {
		return
	}
	if q.Name != testQuery {
		return
	}

	// Always respond with TXT "ok"
	m := new(dns.Msg)
	m.SetReply(req)
	m.Authoritative = true
	m.RecursionAvailable = true
	header := dns.RR_Header{Name: q.Name, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0}
	txt := &dns.TXT{Hdr: header, Txt: []string{"ok"}}
	m.Answer = append(m.Answer, txt)
	d.addSOA(consulDomain, m)
	if err := resp.WriteMsg(m); err != nil {
		d.logger.Printf("[WARN] dns: failed to respond: %v", err)
	}
}
Example #20
0
// Performs the actual query by service name (browse) or service instance name (lookup),
// start response listeners goroutines and loops over the entries channel.
func (c *client) query(params *LookupParams) error {
	var serviceName, serviceInstanceName string
	serviceName = fmt.Sprintf("%s.%s.", trimDot(params.Service), trimDot(params.Domain))
	if params.Instance != "" {
		serviceInstanceName = fmt.Sprintf("%s.%s", params.Instance, serviceName)
	}

	// send the query
	m := new(dns.Msg)
	if serviceInstanceName != "" {
		m.Question = []dns.Question{
			dns.Question{serviceInstanceName, dns.TypeSRV, dns.ClassINET},
			dns.Question{serviceInstanceName, dns.TypeTXT, dns.ClassINET},
		}
		m.RecursionDesired = false
	} else {
		m.SetQuestion(serviceName, dns.TypePTR)
		m.RecursionDesired = false
	}
	if err := c.sendQuery(m); err != nil {
		return err
	}

	return nil
}
Example #21
0
// Data receiving routine reads from connection, unpacks packets into dns.Msg
// structures and sends them to a given msgCh channel
func (c *client) recv(l *net.UDPConn, msgCh chan *dns.Msg) {
	if l == nil {
		return
	}
	buf := make([]byte, 65536)
	for !c.closed {
		n, _, err := l.ReadFrom(buf)
		if err != nil {
			continue
		}
		msg := new(dns.Msg)
		if err := msg.Unpack(buf[:n]); err != nil {
			log.Printf("[ERR] mdns: Failed to unpack packet: %v", err)
			continue
		}
		select {
		case msgCh <- msg:
		case <-c.closedCh:
			return
		}
	}
}
Example #22
0
// serviceARecords is used to add the SRV records for a service lookup
func (d *DNSServer) serviceSRVRecords(dc string, nodes structs.CheckServiceNodes, req, resp *dns.Msg, ttl time.Duration) {
	handled := make(map[string]struct{})
	for _, node := range nodes {
		// Avoid duplicate entries, possible if a node has
		// the same service the same port, etc.
		tuple := fmt.Sprintf("%s:%s:%d", node.Node.Node, node.Service.Address, node.Service.Port)
		if _, ok := handled[tuple]; ok {
			continue
		}
		handled[tuple] = struct{}{}

		// Add the SRV record
		srvRec := &dns.SRV{
			Hdr: dns.RR_Header{
				Name:   req.Question[0].Name,
				Rrtype: dns.TypeSRV,
				Class:  dns.ClassINET,
				Ttl:    uint32(ttl / time.Second),
			},
			Priority: 1,
			Weight:   1,
			Port:     uint16(node.Service.Port),
			Target:   fmt.Sprintf("%s.node.%s.%s", node.Node.Node, dc, d.domain),
		}
		resp.Answer = append(resp.Answer, srvRec)

		// Determine advertised address
		addr := node.Node.Address
		if node.Service.Address != "" {
			addr = node.Service.Address
		}

		// Add the extra record
		records := d.formatNodeRecord(&node.Node, addr, srvRec.Target, dns.TypeANY, ttl)
		if records != nil {
			resp.Extra = append(resp.Extra, records...)
		}
	}
}
Example #23
0
func TestDNS_Recurse(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	m := new(dns.Msg)
	m.SetQuestion("apple.com.", dns.TypeANY)

	c := new(dns.Client)
	c.Net = "tcp"
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	if len(in.Answer) == 0 {
		t.Fatalf("Bad: %#v", in)
	}
	if in.Rcode != dns.RcodeSuccess {
		t.Fatalf("Bad: %#v", in)
	}
}
Example #24
0
// Perform probing & announcement
//TODO: implement a proper probing & conflict resolution
func (s *server) probe() {
	q := new(dns.Msg)
	q.SetQuestion(s.service.ServiceInstanceName(), dns.TypePTR)
	q.RecursionDesired = false

	srv := &dns.SRV{
		Hdr: dns.RR_Header{
			Name:   s.service.ServiceInstanceName(),
			Rrtype: dns.TypeSRV,
			Class:  dns.ClassINET,
			Ttl:    3200,
		},
		Priority: 0,
		Weight:   0,
		Port:     uint16(s.service.Port),
		Target:   s.service.HostName,
	}
	txt := &dns.TXT{
		Hdr: dns.RR_Header{
			Name:   s.service.ServiceInstanceName(),
			Rrtype: dns.TypeTXT,
			Class:  dns.ClassINET,
			Ttl:    3200,
		},
		Txt: s.service.Text,
	}
	q.Ns = []dns.RR{srv, txt}

	randomizer := rand.New(rand.NewSource(time.Now().UnixNano()))
	for i := 0; i < 3; i++ {
		if err := s.multicastResponse(q); err != nil {
			log.Println("[ERR] bonjour: failed to send probe:", err.Error())
		}
		time.Sleep(time.Duration(randomizer.Intn(250)) * time.Millisecond)
	}

	resp := new(dns.Msg)
	resp.Answer = []dns.RR{}
	resp.Extra = []dns.RR{}
	s.composeLookupAnswers(resp, 3200)
	for i := 0; i < 3; i++ {
		if err := s.multicastResponse(resp); err != nil {
			log.Println("[ERR] bonjour: failed to send announcement:", err.Error())
		}
		time.Sleep(2 * time.Second)
	}
}
Example #25
0
// handleQUery is used to handle DNS queries in the configured domain
func (d *DNSServer) handleQuery(resp dns.ResponseWriter, req *dns.Msg) {
	q := req.Question[0]
	defer func(s time.Time) {
		d.logger.Printf("[DEBUG] dns: request for %v (%v)", q, time.Now().Sub(s))
	}(time.Now())

	// Check if this is potentially a test query
	if q.Name == testQuery {
		d.handleTest(resp, req)
		return
	}

	// Switch to TCP if the client is
	network := "udp"
	if _, ok := resp.RemoteAddr().(*net.TCPAddr); ok {
		network = "tcp"
	}

	// Setup the message response
	m := new(dns.Msg)
	m.SetReply(req)
	m.Authoritative = true
	m.RecursionAvailable = (len(d.recursors) > 0)

	// Only add the SOA if requested
	if req.Question[0].Qtype == dns.TypeSOA {
		d.addSOA(d.domain, m)
	}

	// Dispatch the correct handler
	d.dispatch(network, req, m)

	// Write out the complete response
	if err := resp.WriteMsg(m); err != nil {
		d.logger.Printf("[WARN] dns: failed to respond: %v", err)
	}
}
Example #26
0
// Retrieve the DNSKEY records of a zone and convert them
// to DS records for SHA1, SHA256 and SHA384.
func ExampleDS(zone string) {
	config, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
	c := new(dns.Client)
	m := new(dns.Msg)
	if zone == "" {
		zone = "miek.nl"
	}
	m.SetQuestion(dns.Fqdn(zone), dns.TypeDNSKEY)
	m.SetEdns0(4096, true)
	r, _, err := c.Exchange(m, config.Servers[0]+":"+config.Port)
	if err != nil {
		return
	}
	if r.Rcode != dns.RcodeSuccess {
		return
	}
	for _, k := range r.Answer {
		if key, ok := k.(*dns.DNSKEY); ok {
			for _, alg := range []uint8{dns.SHA1, dns.SHA256, dns.SHA384} {
				fmt.Printf("%s; %d\n", key.ToDS(alg).String(), key.Flags)
			}
		}
	}
}
Example #27
0
// addSOA is used to add an SOA record to a message for the given domain
func (d *DNSServer) addSOA(domain string, msg *dns.Msg) {
	soa := &dns.SOA{
		Hdr: dns.RR_Header{
			Name:   domain,
			Rrtype: dns.TypeSOA,
			Class:  dns.ClassINET,
			Ttl:    0,
		},
		Ns:      "ns." + domain,
		Mbox:    "postmaster." + domain,
		Serial:  uint32(time.Now().Unix()),
		Refresh: 3600,
		Retry:   600,
		Expire:  86400,
		Minttl:  0,
	}
	msg.Ns = append(msg.Ns, soa)
}
Example #28
0
// handlePtr is used to handle "reverse" DNS queries
func (d *DNSServer) handlePtr(resp dns.ResponseWriter, req *dns.Msg) {
	q := req.Question[0]
	defer func(s time.Time) {
		d.logger.Printf("[DEBUG] dns: request for %v (%v)", q, time.Now().Sub(s))
	}(time.Now())

	// Setup the message response
	m := new(dns.Msg)
	m.SetReply(req)
	m.Authoritative = true
	m.RecursionAvailable = (len(d.recursors) > 0)

	// Only add the SOA if requested
	if req.Question[0].Qtype == dns.TypeSOA {
		d.addSOA(d.domain, m)
	}

	datacenter := d.agent.config.Datacenter

	// Get the QName without the domain suffix
	qName := strings.ToLower(dns.Fqdn(req.Question[0].Name))

	args := structs.DCSpecificRequest{
		Datacenter:   datacenter,
		QueryOptions: structs.QueryOptions{AllowStale: d.config.AllowStale},
	}
	var out structs.IndexedNodes

	// TODO: Replace ListNodes with an internal RPC that can do the filter
	// server side to avoid transferring the entire node list.
	if err := d.agent.RPC("Catalog.ListNodes", &args, &out); err == nil {
		for _, n := range out.Nodes {
			arpa, _ := dns.ReverseAddr(n.Address)
			if arpa == qName {
				ptr := &dns.PTR{
					Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: 0},
					Ptr: fmt.Sprintf("%s.node.%s.%s", n.Node, datacenter, d.domain),
				}
				m.Answer = append(m.Answer, ptr)
				break
			}
		}
	}

	// Write out the complete response
	if err := resp.WriteMsg(m); err != nil {
		d.logger.Printf("[WARN] dns: failed to respond: %v", err)
	}
}
Example #29
0
// serviceNodeRecords is used to add the node records for a service lookup
func (d *DNSServer) serviceNodeRecords(nodes structs.CheckServiceNodes, req, resp *dns.Msg, ttl time.Duration) {
	qName := req.Question[0].Name
	qType := req.Question[0].Qtype
	handled := make(map[string]struct{})
	for _, node := range nodes {
		// Avoid duplicate entries, possible if a node has
		// the same service on multiple ports, etc.
		addr := node.Node.Address
		if node.Service.Address != "" {
			addr = node.Service.Address
		}

		if _, ok := handled[addr]; ok {
			continue
		}
		handled[addr] = struct{}{}

		// Add the node record
		records := d.formatNodeRecord(&node.Node, addr, qName, qType, ttl)
		if records != nil {
			resp.Answer = append(resp.Answer, records...)
		}
	}
}
Example #30
0
func TestDNS_ServiceLookup_FilterCritical(t *testing.T) {
	dir, srv := makeDNSServer(t)
	defer os.RemoveAll(dir)
	defer srv.agent.Shutdown()

	testutil.WaitForLeader(t, srv.agent.RPC, "dc1")

	// Register nodes
	args := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "foo",
		Address:    "127.0.0.1",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"master"},
			Port:    12345,
		},
		Check: &structs.HealthCheck{
			CheckID: "serf",
			Name:    "serf",
			Status:  structs.HealthCritical,
		},
	}

	var out struct{}
	if err := srv.agent.RPC("Catalog.Register", args, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	args2 := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "bar",
		Address:    "127.0.0.2",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"master"},
			Port:    12345,
		},
		Check: &structs.HealthCheck{
			CheckID: "serf",
			Name:    "serf",
			Status:  structs.HealthCritical,
		},
	}
	if err := srv.agent.RPC("Catalog.Register", args2, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	args3 := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "bar",
		Address:    "127.0.0.2",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"master"},
			Port:    12345,
		},
		Check: &structs.HealthCheck{
			CheckID:   "db",
			Name:      "db",
			ServiceID: "db",
			Status:    structs.HealthCritical,
		},
	}
	if err := srv.agent.RPC("Catalog.Register", args3, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	args4 := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "baz",
		Address:    "127.0.0.3",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"master"},
			Port:    12345,
		},
	}
	if err := srv.agent.RPC("Catalog.Register", args4, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	args5 := &structs.RegisterRequest{
		Datacenter: "dc1",
		Node:       "quux",
		Address:    "127.0.0.4",
		Service: &structs.NodeService{
			Service: "db",
			Tags:    []string{"master"},
			Port:    12345,
		},
		Check: &structs.HealthCheck{
			CheckID:   "db",
			Name:      "db",
			ServiceID: "db",
			Status:    structs.HealthWarning,
		},
	}
	if err := srv.agent.RPC("Catalog.Register", args5, &out); err != nil {
		t.Fatalf("err: %v", err)
	}

	m := new(dns.Msg)
	m.SetQuestion("db.service.consul.", dns.TypeANY)

	c := new(dns.Client)
	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
	in, _, err := c.Exchange(m, addr.String())
	if err != nil {
		t.Fatalf("err: %v", err)
	}

	// Only 4 and 5 are not failing, so we should get 2 answers
	if len(in.Answer) != 2 {
		t.Fatalf("Bad: %#v", in)
	}

	ips := make(map[string]bool)
	for _, resp := range in.Answer {
		aRec := resp.(*dns.A)
		ips[aRec.A.String()] = true
	}

	if !ips["127.0.0.3"] {
		t.Fatalf("Bad: %#v should contain 127.0.0.3 (state healthy)", in)
	}
	if !ips["127.0.0.4"] {
		t.Fatalf("Bad: %#v should contain 127.0.0.4 (state warning)", in)
	}
}