Exemplo n.º 1
0
func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.Msg, error) {
	addr, ipv6Miss := r.sb.ResolveName(name, ipType)
	if addr == nil && ipv6Miss {
		// Send a reply without any Answer sections
		log.Debugf("Lookup name %s present without IPv6 address", name)
		resp := createRespMsg(query)
		return resp, nil
	}
	if addr == nil {
		return nil, nil
	}

	log.Debugf("Lookup for %s: IP %v", name, addr)

	resp := createRespMsg(query)
	if len(addr) > 1 {
		addr = shuffleAddr(addr)
	}
	if ipType == types.IPv4 {
		for _, ip := range addr {
			rr := new(dns.A)
			rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: respTTL}
			rr.A = ip
			resp.Answer = append(resp.Answer, rr)
		}
	} else {
		for _, ip := range addr {
			rr := new(dns.AAAA)
			rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: respTTL}
			rr.AAAA = ip
			resp.Answer = append(resp.Answer, rr)
		}
	}
	return resp, nil
}
Exemplo n.º 2
0
func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.Msg, error) {
	addr := r.sb.ResolveName(name, ipType)
	if addr == nil {
		return nil, nil
	}

	log.Debugf("Lookup for %s: IP %v", name, addr)

	resp := new(dns.Msg)
	resp.SetReply(query)
	setCommonFlags(resp)

	if len(addr) > 1 {
		addr = shuffleAddr(addr)
	}
	if ipType == netutils.IPv4 {
		for _, ip := range addr {
			rr := new(dns.A)
			rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: respTTL}
			rr.A = ip
			resp.Answer = append(resp.Answer, rr)
		}
	} else {
		for _, ip := range addr {
			rr := new(dns.AAAA)
			rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: respTTL}
			rr.AAAA = ip
			resp.Answer = append(resp.Answer, rr)
		}
	}
	return resp, nil
}
Exemplo n.º 3
0
func route(w dns.ResponseWriter, req *dns.Msg) {
	if len(req.Question) != 1 {
		failWithRcode(w, req, dns.RcodeRefused)
		return
	}
	question := req.Question[0]
	qtype := question.Qtype
	if question.Qclass != dns.ClassINET {
		failWithRcode(w, req, dns.RcodeRefused)
		return
	}
	remoteIP := w.RemoteAddr().(*net.UDPAddr).IP
	m := new(dns.Msg)
	m.Id = req.Id
	switch qtype {
	case dns.TypeA:
		if remoteIP4 := remoteIP.To4(); remoteIP4 != nil {
			rr := new(dns.A)
			rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
				Class: dns.ClassINET, Ttl: 10}
			rr.A = remoteIP4
			m.Answer = []dns.RR{rr}
		}
	case dns.TypeAAAA:
		if remoteIP16 := remoteIP.To16(); remoteIP16 != nil {
			rr := new(dns.AAAA)
			rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
				Class: dns.ClassINET, Ttl: 10}
			rr.AAAA = remoteIP16
			m.Answer = []dns.RR{rr}
		}
	case dns.TypeTXT:
		rr := new(dns.TXT)
		rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
			Class: dns.ClassINET, Ttl: 10}
		rr.Txt = []string{fmt.Sprintf("Resolver IP: %v", remoteIP.String())}
		m.Answer = []dns.RR{rr}
	}
	m.Question = req.Question
	m.Response = true
	m.Authoritative = true
	w.WriteMsg(m)
}
Exemplo n.º 4
0
func parseValue(t uint16, value string, h dns.RR_Header) dns.RR {
	switch t {
	case dns.TypeA:
		a := new(dns.A)
		a.Hdr = h
		a.A, _ = parseA(value)
		return a
	case dns.TypeAAAA:
		aaaa := new(dns.AAAA)
		aaaa.Hdr = h
		aaaa.AAAA, _ = parseAAAA(value)
		return aaaa
	case dns.TypeSRV:
		srv := new(dns.SRV)
		srv.Hdr = h
		srv.Priority, srv.Weight, srv.Port, srv.Target, _ = parseSRV(value)
		return srv
	}
	return nil
}
Exemplo n.º 5
0
func answerAAAA(q *dns.Question, v *DNSValue) dns.RR {
	answer := new(dns.AAAA)
	answer.Header().Name = q.Name
	answer.Header().Rrtype = dns.TypeAAAA
	answer.Header().Class = dns.ClassINET
	answer.AAAA = net.ParseIP(v.Value)
	return answer
}
Exemplo n.º 6
0
func (s *server) AddressRecords(q dns.Question) (records []dns.RR, err error) {
	name := strings.ToLower(q.Name)
	if name == "master."+s.config.Domain || name == s.config.Domain {
		for _, m := range s.client.GetCluster() {
			u, e := url.Parse(m)
			if e != nil {
				continue
			}
			h, _, e := net.SplitHostPort(u.Host)
			if e != nil {
				continue
			}
			ip := net.ParseIP(h)
			switch {
			case ip.To4() != nil && q.Qtype == dns.TypeA:
				records = append(records, &dns.A{Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.Ttl}, A: ip.To4()})
			case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
				records = append(records, &dns.AAAA{Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.Ttl}, AAAA: ip.To16()})
			}
		}
		return
	}
	r, err := s.client.Get(path(name), false, true)
	if err != nil {
		println(err.Error())
		return nil, err
	}
	var serv *Service
	if !r.Node.Dir { // single element
		if err := json.Unmarshal([]byte(r.Node.Value), &serv); err != nil {
			log.Printf("error: Failure to parse value: %q", err)
			return nil, err
		}
		ip := net.ParseIP(serv.Host)
		ttl := uint32(r.Node.TTL)
		if ttl == 0 {
			ttl = s.Ttl
		}
		switch {
		case ip == nil:
		case ip.To4() != nil && q.Qtype == dns.TypeA:
			a := new(dns.A)
			a.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: ttl}
			a.A = ip.To4()
			records = append(records, a)
		case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
			aaaa := new(dns.AAAA)
			aaaa.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: ttl}
			aaaa.AAAA = ip.To16()
			records = append(records, aaaa)
		}
		return records, nil
	}
	for _, serv := range s.loopNodes(&r.Node.Nodes) {
		ip := net.ParseIP(serv.Host)
		switch {
		case ip == nil:
		case ip.To4() != nil && q.Qtype == dns.TypeA:
			a := new(dns.A)
			a.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: uint32(r.Node.TTL)}
			a.A = ip.To4()
			records = append(records, a)
		case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
			aaaa := new(dns.AAAA)
			aaaa.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: uint32(r.Node.TTL)}
			aaaa.AAAA = ip.To16()
			records = append(records, aaaa)
		}
	}
	if s.config.RoundRobin {
		switch l := len(records); l {
		case 2:
			if dns.Id()%2 == 0 {
				records[0], records[1] = records[1], records[0]
			}
		default:
			// Do a minimum of l swap, maximum of 4l swaps
			for j := 0; j < l*(int(dns.Id())%4+1); j++ {
				q := int(dns.Id()) % l
				p := int(dns.Id()) % l
				if q == p {
					p = (p + 1) % l
				}
				records[q], records[p] = records[p], records[q]
			}
		}
	}
	return records, nil
}
Exemplo n.º 7
0
// updateDNS updates the current slices of dns.RR so incoming requests get a
// fast answer
func updateDNS(s *dnsseeder) {

	var rr4std, rr4non, rr6std, rr6non []dns.RR

	s.mtx.RLock()

	// loop over each dns recprd type we need
	for t := range []int{dnsV4Std, dnsV4Non, dnsV6Std, dnsV6Non} {
		// FIXME above needs to be convertwd into one scan of theList if possible

		numRR := 0

		for _, nd := range s.theList {
			// when we reach max exit
			if numRR >= 25 {
				break
			}

			if nd.status != statusCG {
				continue
			}

			if t == dnsV4Std || t == dnsV4Non {
				if t == dnsV4Std && nd.dnsType == dnsV4Std {
					r := new(dns.A)
					r.Hdr = dns.RR_Header{Name: s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
					r.A = nd.na.IP
					rr4std = append(rr4std, r)
					numRR++
				}

				// if the node is using a non standard port then add the encoded port info to DNS
				if t == dnsV4Non && nd.dnsType == dnsV4Non {
					r := new(dns.A)
					r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
					r.A = nd.na.IP
					rr4non = append(rr4non, r)
					numRR++
					r = new(dns.A)
					r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
					r.A = nd.nonstdIP
					rr4non = append(rr4non, r)
					numRR++
				}
			}
			if t == dnsV6Std || t == dnsV6Non {
				if t == dnsV6Std && nd.dnsType == dnsV6Std {
					r := new(dns.AAAA)
					r.Hdr = dns.RR_Header{Name: s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
					r.AAAA = nd.na.IP
					rr6std = append(rr6std, r)
					numRR++
				}
				// if the node is using a non standard port then add the encoded port info to DNS
				if t == dnsV6Non && nd.dnsType == dnsV6Non {
					r := new(dns.AAAA)
					r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
					r.AAAA = nd.na.IP
					rr6non = append(rr6non, r)
					numRR++
					r = new(dns.AAAA)
					r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
					r.AAAA = nd.nonstdIP
					rr6non = append(rr6non, r)
					numRR++
				}
			}

		}

	}

	s.mtx.RUnlock()

	config.dnsmtx.Lock()

	// update the map holding the details for this seeder
	for t := range []int{dnsV4Std, dnsV4Non, dnsV6Std, dnsV6Non} {
		switch t {
		case dnsV4Std:
			config.dns[s.dnsHost+".A"] = rr4std
		case dnsV4Non:
			config.dns["nonstd."+s.dnsHost+".A"] = rr4non
		case dnsV6Std:
			config.dns[s.dnsHost+".AAAA"] = rr6std
		case dnsV6Non:
			config.dns["nonstd."+s.dnsHost+".AAAA"] = rr6non
		}
	}

	config.dnsmtx.Unlock()

	if config.stats {
		s.counts.mtx.RLock()
		log.Printf("%s - DNS available: v4std: %v v4non: %v v6std: %v v6non: %v\n", s.name, len(rr4std), len(rr4non), len(rr6std), len(rr6non))
		log.Printf("%s - DNS counts: v4std: %v v4non: %v v6std: %v v6non: %v total: %v\n",
			s.name,
			s.counts.DNSCounts[dnsV4Std],
			s.counts.DNSCounts[dnsV4Non],
			s.counts.DNSCounts[dnsV6Std],
			s.counts.DNSCounts[dnsV6Non],
			s.counts.DNSCounts[dnsV4Std]+s.counts.DNSCounts[dnsV4Non]+s.counts.DNSCounts[dnsV6Std]+s.counts.DNSCounts[dnsV6Non])

		s.counts.mtx.RUnlock()

	}
}