Example #1
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 #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])
}