Ejemplo n.º 1
0
func statusRR(label string) []dns.RR {
	h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
	h.Name = label

	status := map[string]string{"v": VERSION, "id": serverID}

	hostname, err := os.Hostname()
	if err == nil {
		status["h"] = hostname
	}

	qCounter := metrics.Get("queries").(metrics.Meter)
	status["up"] = strconv.Itoa(int(time.Since(timeStarted).Seconds()))
	status["qs"] = strconv.FormatInt(qCounter.Count(), 10)
	status["qps1"] = fmt.Sprintf("%.4f", qCounter.Rate1())

	js, err := json.Marshal(status)

	return []dns.RR{&dns.TXT{Hdr: h, Txt: []string{string(js)}}}
}
Ejemplo n.º 2
0
func setupZoneData(data map[string]interface{}, Zone *Zone) {
	recordTypes := map[string]uint16{
		"a":     dns.TypeA,
		"aaaa":  dns.TypeAAAA,
		"alias": dns.TypeMF,
		"cname": dns.TypeCNAME,
		"mx":    dns.TypeMX,
		"ns":    dns.TypeNS,
		"txt":   dns.TypeTXT,
		"spf":   dns.TypeSPF,
		"srv":   dns.TypeSRV,
	}

	for dk, dv_inter := range data {
		dv := dv_inter.(map[string]interface{})

		//log.Printf("K %s V %s TYPE-V %T\n", dk, dv, dv)

		label := Zone.AddLabel(dk)

		for rType, rdata := range dv {
			switch rType {
			case "max_hosts":
				label.MaxHosts = valueToInt(rdata)
				continue
			case "ttl":
				label.Ttl = valueToInt(rdata)
				continue
			}

			dnsType, ok := recordTypes[rType]
			if !ok {
				log.Printf("Unsupported record type '%s'\n", rType)
				continue
			}

			if rdata == nil {
				//log.Printf("No %s records for label %s\n", rType, dk)
				continue
			}

			//log.Printf("rdata %s TYPE-R %T\n", rdata, rdata)

			records := make(map[string][]interface{})

			switch rdata.(type) {
			case map[string]interface{}:
				// Handle NS map syntax, map[ns2.example.net:<nil> ns1.example.net:<nil>]
				tmp := make([]interface{}, 0)
				for rdataK, rdataV := range rdata.(map[string]interface{}) {
					if rdataV == nil {
						rdataV = ""
					}
					tmp = append(tmp, []string{rdataK, rdataV.(string)})
				}
				records[rType] = tmp
			case string:
				// CNAME and alias
				tmp := make([]interface{}, 1)
				tmp[0] = rdata.(string)
				records[rType] = tmp
			default:
				records[rType] = rdata.([]interface{})
			}

			//log.Printf("RECORDS %s TYPE-REC %T\n", Records, Records)

			label.Records[dnsType] = make(Records, len(records[rType]))

			for i := 0; i < len(records[rType]); i++ {
				//log.Printf("RT %T %#v\n", records[rType][i], records[rType][i])

				record := new(Record)

				var h dns.RR_Header
				h.Class = dns.ClassINET
				h.Rrtype = dnsType

				// We add the TTL as a last pass because we might not have
				// processed it yet when we process the record data.

				switch len(label.Label) {
				case 0:
					h.Name = Zone.Origin + "."
				default:
					h.Name = label.Label + "." + Zone.Origin + "."
				}

				switch dnsType {
				case dns.TypeA, dns.TypeAAAA:

					str, weight := getStringWeight(records[rType][i].([]interface{}))
					ip := str
					record.Weight = weight

					switch dnsType {
					case dns.TypeA:
						if x := net.ParseIP(ip); x != nil {
							record.RR = &dns.A{Hdr: h, A: x}
							break
						}
						panic(fmt.Errorf("Bad A record %s for %s", ip, dk))
					case dns.TypeAAAA:
						if x := net.ParseIP(ip); x != nil {
							record.RR = &dns.AAAA{Hdr: h, AAAA: x}
							break
						}
						panic(fmt.Errorf("Bad AAAA record %s for %s", ip, dk))
					}

				case dns.TypeMX:
					rec := records[rType][i].(map[string]interface{})
					pref := uint16(0)
					mx := rec["mx"].(string)
					if !strings.HasSuffix(mx, ".") {
						mx = mx + "."
					}
					if rec["weight"] != nil {
						record.Weight = valueToInt(rec["weight"])
					}
					if rec["preference"] != nil {
						pref = uint16(valueToInt(rec["preference"]))
					}
					record.RR = &dns.MX{
						Hdr:        h,
						Mx:         mx,
						Preference: pref}

				case dns.TypeSRV:
					rec := records[rType][i].(map[string]interface{})
					priority := uint16(0)
					srv_weight := uint16(0)
					port := uint16(0)
					target := rec["target"].(string)

					if !dns.IsFqdn(target) {
						target = target + "." + Zone.Origin
					}

					if rec["srv_weight"] != nil {
						srv_weight = uint16(valueToInt(rec["srv_weight"]))
					}
					if rec["port"] != nil {
						port = uint16(valueToInt(rec["port"]))
					}
					if rec["priority"] != nil {
						priority = uint16(valueToInt(rec["priority"]))
					}
					record.RR = &dns.SRV{
						Hdr:      h,
						Priority: priority,
						Weight:   srv_weight,
						Port:     port,
						Target:   target}

				case dns.TypeCNAME:
					rec := records[rType][i]
					var target string
					var weight int
					switch rec.(type) {
					case string:
						target = rec.(string)
					case []interface{}:
						target, weight = getStringWeight(rec.([]interface{}))
					}
					if !dns.IsFqdn(target) {
						target = target + "." + Zone.Origin
					}
					record.Weight = weight
					record.RR = &dns.CNAME{Hdr: h, Target: dns.Fqdn(target)}

				case dns.TypeMF:
					rec := records[rType][i]
					// MF records (how we store aliases) are not FQDNs
					record.RR = &dns.MF{Hdr: h, Mf: rec.(string)}

				case dns.TypeNS:
					rec := records[rType][i]
					if h.Ttl < 86400 {
						h.Ttl = 86400
					}

					var ns string

					switch rec.(type) {
					case string:
						ns = rec.(string)
					case []string:
						recl := rec.([]string)
						ns = recl[0]
						if len(recl[1]) > 0 {
							log.Println("NS records with names syntax not supported")
						}
					default:
						log.Printf("Data: %T %#v\n", rec, rec)
						panic("Unrecognized NS format/syntax")
					}

					rr := &dns.NS{Hdr: h, Ns: dns.Fqdn(ns)}

					record.RR = rr

				case dns.TypeTXT:
					rec := records[rType][i]

					var txt string

					switch rec.(type) {
					case string:
						txt = rec.(string)
					case map[string]interface{}:

						recmap := rec.(map[string]interface{})

						if weight, ok := recmap["weight"]; ok {
							record.Weight = valueToInt(weight)
						}
						if t, ok := recmap["txt"]; ok {
							txt = t.(string)
						}
					}
					if len(txt) > 0 {
						rr := &dns.TXT{Hdr: h, Txt: []string{txt}}
						record.RR = rr
					} else {
						log.Printf("Zero length txt record for '%s' in '%s'\n", label.Label, Zone.Origin)
						continue
					}
					// Initial SPF support added here, cribbed from the TypeTXT case definition - SPF records should be handled identically

				case dns.TypeSPF:
					rec := records[rType][i]

					var spf string

					switch rec.(type) {
					case string:
						spf = rec.(string)
					case map[string]interface{}:

						recmap := rec.(map[string]interface{})

						if weight, ok := recmap["weight"]; ok {
							record.Weight = valueToInt(weight)
						}
						if t, ok := recmap["spf"]; ok {
							spf = t.(string)
						}
					}
					if len(spf) > 0 {
						rr := &dns.SPF{Hdr: h, Txt: []string{spf}}
						record.RR = rr
					} else {
						log.Printf("Zero length SPF record for '%s' in '%s'\n", label.Label, Zone.Origin)
						continue
					}

				default:
					log.Println("type:", rType)
					panic("Don't know how to handle this type")
				}

				if record.RR == nil {
					panic("record.RR is nil")
				}

				label.Weight[dnsType] += record.Weight
				label.Records[dnsType][i] = *record
			}
			if label.Weight[dnsType] > 0 {
				sort.Sort(RecordsByWeight{label.Records[dnsType]})
			}
		}
	}

	// loop over exisiting labels, create zone records for missing sub-domains
	// and set TTLs
	for k := range Zone.Labels {
		if strings.Contains(k, ".") {
			subLabels := strings.Split(k, ".")
			for i := 1; i < len(subLabels); i++ {
				subSubLabel := strings.Join(subLabels[i:], ".")
				if _, ok := Zone.Labels[subSubLabel]; !ok {
					Zone.AddLabel(subSubLabel)
				}
			}
		}
		if Zone.Labels[k].Ttl > 0 {
			for _, records := range Zone.Labels[k].Records {
				for _, r := range records {
					r.RR.Header().Ttl = uint32(Zone.Labels[k].Ttl)
				}
			}
		}
	}

	setupSOA(Zone)

	//log.Println(Zones[k])
}
Ejemplo n.º 3
0
func serve(w dns.ResponseWriter, req *dns.Msg, z *Zone) {

	qtype := req.Question[0].Qtype

	logPrintf("[zone %s] incoming %s %s %d from %s\n", z.Origin, req.Question[0].Name,
		dns.TypeToString[qtype], req.MsgHdr.Id, w.RemoteAddr())

	// Global meter
	metrics.Get("queries").(metrics.Meter).Mark(1)

	// Zone meter
	z.Metrics.Queries.Mark(1)

	logPrintln("Got request", req)

	label := getQuestionName(z, req)

	z.Metrics.LabelStats.Add(label)

	realIp, _, _ := net.SplitHostPort(w.RemoteAddr().String())

	z.Metrics.ClientStats.Add(realIp)

	var ip net.IP // EDNS or real IP
	var edns *dns.EDNS0_SUBNET
	var opt_rr *dns.OPT

	for _, extra := range req.Extra {

		switch extra.(type) {
		case *dns.OPT:
			for _, o := range extra.(*dns.OPT).Option {
				opt_rr = extra.(*dns.OPT)
				switch e := o.(type) {
				case *dns.EDNS0_NSID:
					// do stuff with e.Nsid
				case *dns.EDNS0_SUBNET:
					z.Metrics.EdnsQueries.Mark(1)
					logPrintln("Got edns", e.Address, e.Family, e.SourceNetmask, e.SourceScope)
					if e.Address != nil {
						edns = e
						ip = e.Address
					}
				}
			}
		}
	}

	if len(ip) == 0 { // no edns subnet
		ip = net.ParseIP(realIp)
	}

	targets, netmask := z.Options.Targeting.GetTargets(ip)

	m := new(dns.Msg)
	m.SetReply(req)
	if e := m.IsEdns0(); e != nil {
		m.SetEdns0(4096, e.Do())
	}
	m.Authoritative = true

	// TODO: set scope to 0 if there are no alternate responses
	if edns != nil {
		if edns.Family != 0 {
			if netmask < 16 {
				netmask = 16
			}
			edns.SourceScope = uint8(netmask)
			m.Extra = append(m.Extra, opt_rr)
		}
	}

	labels, labelQtype := z.findLabels(label, targets, qTypes{dns.TypeMF, dns.TypeCNAME, qtype})
	if labelQtype == 0 {
		labelQtype = qtype
	}

	if labels == nil {

		firstLabel := (strings.Split(label, "."))[0]

		if firstLabel == "_status" {
			if qtype == dns.TypeANY || qtype == dns.TypeTXT {
				m.Answer = statusRR(label + "." + z.Origin + ".")
			} else {
				m.Ns = append(m.Ns, z.SoaRR())
			}
			m.Authoritative = true
			w.WriteMsg(m)
			return
		}

		if firstLabel == "_country" {
			if qtype == dns.TypeANY || qtype == dns.TypeTXT {
				h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
				h.Name = label + "." + z.Origin + "."

				txt := []string{
					w.RemoteAddr().String(),
					ip.String(),
				}

				targets, netmask := z.Options.Targeting.GetTargets(ip)
				txt = append(txt, strings.Join(targets, " "))
				txt = append(txt, fmt.Sprintf("/%d", netmask), serverID, serverIP)

				m.Answer = []dns.RR{&dns.TXT{Hdr: h,
					Txt: txt,
				}}
			} else {
				m.Ns = append(m.Ns, z.SoaRR())
			}

			m.Authoritative = true
			w.WriteMsg(m)
			return
		}

		// return NXDOMAIN
		m.SetRcode(req, dns.RcodeNameError)
		m.Authoritative = true

		m.Ns = []dns.RR{z.SoaRR()}

		w.WriteMsg(m)
		return
	}

	if servers := labels.Picker(labelQtype, labels.MaxHosts); servers != nil {
		var rrs []dns.RR
		for _, record := range servers {
			rr := record.RR
			rr.Header().Name = req.Question[0].Name
			rrs = append(rrs, rr)
		}
		m.Answer = rrs
	}

	if len(m.Answer) == 0 {
		m.Ns = append(m.Ns, z.SoaRR())
	}

	logPrintln(m)

	err := w.WriteMsg(m)
	if err != nil {
		// if Pack'ing fails the Write fails. Return SERVFAIL.
		log.Println("Error writing packet", m)
		dns.HandleFailed(w, req)
	}
	return
}
Ejemplo n.º 4
0
func serve(w dns.ResponseWriter, req *dns.Msg, z *Zone) {

	qtype := req.Question[0].Qtype

	logPrintf("[zone %s] incoming  %s %s (id %d) from %s\n", z.Origin, req.Question[0].Name,
		dns.TypeToString[qtype], req.Id, w.RemoteAddr())

	// Global meter
	metrics.Get("queries").(metrics.Meter).Mark(1)

	// Zone meter
	z.Metrics.Queries.Mark(1)

	logPrintln("Got request", req)

	label := getQuestionName(z, req)

	z.Metrics.LabelStats.Add(label)

	// IP that's talking to us (not EDNS CLIENT SUBNET)
	var realIP net.IP

	if addr, ok := w.RemoteAddr().(*net.UDPAddr); ok {
		realIP = make(net.IP, len(addr.IP))
		copy(realIP, addr.IP)
	} else if addr, ok := w.RemoteAddr().(*net.TCPAddr); ok {
		realIP = make(net.IP, len(addr.IP))
		copy(realIP, addr.IP)
	}

	z.Metrics.ClientStats.Add(realIP.String())

	var ip net.IP // EDNS or real IP
	var edns *dns.EDNS0_SUBNET
	var opt_rr *dns.OPT

	for _, extra := range req.Extra {

		switch extra.(type) {
		case *dns.OPT:
			for _, o := range extra.(*dns.OPT).Option {
				opt_rr = extra.(*dns.OPT)
				switch e := o.(type) {
				case *dns.EDNS0_NSID:
					// do stuff with e.Nsid
				case *dns.EDNS0_SUBNET:
					z.Metrics.EdnsQueries.Mark(1)
					logPrintln("Got edns", e.Address, e.Family, e.SourceNetmask, e.SourceScope)
					if e.Address != nil {
						edns = e
						ip = e.Address
					}
				}
			}
		}
	}

	if len(ip) == 0 { // no edns subnet
		ip = realIP
	}

	targets, netmask := z.Options.Targeting.GetTargets(ip)

	m := new(dns.Msg)
	m.SetReply(req)
	if e := m.IsEdns0(); e != nil {
		m.SetEdns0(4096, e.Do())
	}
	m.Authoritative = true

	// TODO: set scope to 0 if there are no alternate responses
	if edns != nil {
		if edns.Family != 0 {
			if netmask < 16 {
				netmask = 16
			}
			edns.SourceScope = uint8(netmask)
			m.Extra = append(m.Extra, opt_rr)
		}
	}

	labels, labelQtype := z.findLabels(label, targets, qTypes{dns.TypeMF, dns.TypeCNAME, qtype})
	if labelQtype == 0 {
		labelQtype = qtype
	}

	if labels == nil {

		permitDebug := !*flagPrivateDebug || (realIP != nil && realIP.IsLoopback())

		firstLabel := (strings.Split(label, "."))[0]

		if permitDebug && firstLabel == "_status" {
			if qtype == dns.TypeANY || qtype == dns.TypeTXT {
				m.Answer = statusRR(label + "." + z.Origin + ".")
			} else {
				m.Ns = append(m.Ns, z.SoaRR())
			}
			m.Authoritative = true
			w.WriteMsg(m)

			t := time.Now()
			logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)

			return
		}

		if firstLabel == "_country" {
			if qtype == dns.TypeANY || qtype == dns.TypeTXT {
				h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
				h.Name = label + "." + z.Origin + "."

				txt := []string{
					w.RemoteAddr().String(),
					ip.String(),
				}

				targets, netmask := z.Options.Targeting.GetTargets(ip)
				txt = append(txt, strings.Join(targets, " "))
				txt = append(txt, fmt.Sprintf("/%d", netmask), serverID, serverIP)

				m.Answer = []dns.RR{&dns.TXT{Hdr: h,
					Txt: txt,
				}}
			} else {
				m.Ns = append(m.Ns, z.SoaRR())
			}

			m.Authoritative = true
			w.WriteMsg(m)

			t := time.Now()
			logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)

			return
		}

		// return NXDOMAIN
		m.SetRcode(req, dns.RcodeNameError)
		m.Authoritative = true

		m.Ns = []dns.RR{z.SoaRR()}
		w.WriteMsg(m)

		t := time.Now()
		logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)

		return
	}

	if servers := labels.Picker(labelQtype, labels.MaxHosts); servers != nil {
		var rrs []dns.RR
		for _, record := range servers {
			rr := dns.Copy(record.RR)
			rr.Header().Name = req.Question[0].Name
			rrs = append(rrs, rr)
		}
		m.Answer = rrs
	}

	if len(m.Answer) == 0 {
		m.Ns = append(m.Ns, z.SoaRR())
	} else {
		if z.Labels[label] != nil {
			z.Labels[label].Hits++
			logPrintln("*********** ", z.Labels[label].Hits)
		}
	}

	//logPrintln(m)

	err := w.WriteMsg(m)
	if err != nil {
		// if Pack'ing fails the Write fails. Return SERVFAIL.
		log.Println("Error writing packet", m)
		dns.HandleFailed(w, req)
	}

	t := time.Now()
	logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)

	return
}