示例#1
0
文件: notify.go 项目: yuewko/coredns
// isNotify checks if state is a notify message and if so, will *also* check if it
// is from one of the configured masters. If not it will not be a valid notify
// message. If the zone z is not a secondary zone the message will also be ignored.
func (z *Zone) isNotify(state middleware.State) bool {
	if state.Req.Opcode != dns.OpcodeNotify {
		return false
	}
	if len(z.TransferFrom) == 0 {
		return false
	}
	remote := middleware.Addr(state.IP()).Normalize()
	for _, from := range z.TransferFrom {
		if from == remote {
			return true
		}
	}
	return false
}
示例#2
0
文件: xfr.go 项目: yuewko/coredns
// Serve an AXFR (and fallback of IXFR) as well.
func (x Xfr) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	state := middleware.State{W: w, Req: r}
	if !x.TransferAllowed(state) {
		return dns.RcodeServerFailure, nil
	}
	if state.QType() != dns.TypeAXFR && state.QType() != dns.TypeIXFR {
		return 0, fmt.Errorf("xfr called with non transfer type: %d", state.QType())
	}

	records := x.All()
	if len(records) == 0 {
		return dns.RcodeServerFailure, nil
	}

	ch := make(chan *dns.Envelope)
	defer close(ch)
	tr := new(dns.Transfer)
	go tr.Out(w, r, ch)

	j, l := 0, 0
	records = append(records, records[0]) // add closing SOA to the end
	log.Printf("[INFO] Outgoing transfer of %d records of zone %s to %s started", len(records), x.origin, state.IP())
	for i, r := range records {
		l += dns.Len(r)
		if l > transferLength {
			ch <- &dns.Envelope{RR: records[j:i]}
			l = 0
			j = i
		}
	}
	if j < len(records) {
		ch <- &dns.Envelope{RR: records[j:]}
	}

	w.Hijack()
	// w.Close() // Client closes connection
	return dns.RcodeSuccess, nil
}
示例#3
0
文件: file.go 项目: yuewko/coredns
func (f File) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	state := middleware.State{W: w, Req: r}

	if state.QClass() != dns.ClassINET {
		return dns.RcodeServerFailure, errors.New("can only deal with ClassINET")
	}
	qname := state.Name()
	zone := middleware.Zones(f.Zones.Names).Matches(qname)
	if zone == "" {
		if f.Next != nil {
			return f.Next.ServeDNS(ctx, w, r)
		}
		return dns.RcodeServerFailure, errors.New("no next middleware found")
	}
	z, ok := f.Zones.Z[zone]
	if !ok {
		return f.Next.ServeDNS(ctx, w, r)
	}
	if z == nil {
		return dns.RcodeServerFailure, nil
	}
	if r.Opcode == dns.OpcodeNotify {
		if z.isNotify(state) {
			m := new(dns.Msg)
			m.SetReply(r)
			m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
			state.SizeAndDo(m)
			w.WriteMsg(m)

			log.Printf("[INFO] Notify from %s for %s: checking transfer", state.IP(), zone)
			ok, err := z.shouldTransfer()
			if ok {
				z.TransferIn()
			} else {
				log.Printf("[INFO] Notify from %s for %s: no serial increase seen", state.IP(), zone)
			}
			if err != nil {
				log.Printf("[WARNING] Notify from %s for %s: failed primary check: %s", state.IP(), zone, err)
			}
			return dns.RcodeSuccess, nil
		}
		log.Printf("[INFO] Dropping notify from %s for %s", state.IP(), zone)
		return dns.RcodeSuccess, nil
	}

	if z.Expired != nil && *z.Expired {
		log.Printf("[ERROR] Zone %s is expired", zone)
		return dns.RcodeServerFailure, nil
	}

	if state.QType() == dns.TypeAXFR || state.QType() == dns.TypeIXFR {
		xfr := Xfr{z}
		return xfr.ServeDNS(ctx, w, r)
	}

	answer, ns, extra, result := z.Lookup(qname, state.QType(), state.Do())

	m := new(dns.Msg)
	m.SetReply(r)
	m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
	m.Answer, m.Ns, m.Extra = answer, ns, extra

	switch result {
	case Success:
	case NoData:
	case NameError:
		m.Rcode = dns.RcodeNameError
	case Delegation:
		m.Authoritative = false
	case ServerFailure:
		return dns.RcodeServerFailure, nil
	}

	state.SizeAndDo(m)
	m, _ = state.Scrub(m)
	w.WriteMsg(m)
	return dns.RcodeSuccess, nil
}