Golang State.Do方法代碼示例

// ServeDNS implements the middleware.Handler interface.
func (d Dnssec) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	state := middleware.State{W: w, Req: r}

	do := state.Do()
	qname := state.Name()
	qtype := state.QType()
	zone := middleware.Zones(d.zones).Matches(qname)
	if zone == "" {
		return d.Next.ServeDNS(ctx, w, r)
	}

	// Intercept queries for DNSKEY, but only if one of the zones matches the qname, otherwise we let
	// the query through.
	if qtype == dns.TypeDNSKEY {
		for _, z := range d.zones {
			if qname == z {
				resp := d.getDNSKEY(state, z, do)
				state.SizeAndDo(resp)
				w.WriteMsg(resp)
				return dns.RcodeSuccess, nil
			}
		}
	}

	drr := NewDnssecResponseWriter(w, d)
	return d.Next.ServeDNS(ctx, drr, r)
}

func (d *DnssecResponseWriter) WriteMsg(res *dns.Msg) error {
	// By definition we should sign anything that comes back, we should still figure out for
	// which zone it should be.
	state := middleware.State{W: d.ResponseWriter, Req: res}

	qname := state.Name()
	zone := middleware.Zones(d.d.zones).Matches(qname)
	if zone == "" {
		return d.ResponseWriter.WriteMsg(res)
	}

	if state.Do() {
		res = d.d.Sign(state, zone, time.Now().UTC())
	}
	state.SizeAndDo(res)

	return d.ResponseWriter.WriteMsg(res)
}

// Report is a plain reporting function that the server can use for REFUSED and other
// queries that are turned down because they don't match any middleware.
func Report(state middleware.State, zone, rcode string, size int, start time.Time) {
	if requestCount == nil {
		// no metrics are enabled
		return
	}

	// Proto and Family
	net := state.Proto()
	fam := "1"
	if state.Family() == 2 {
		fam = "2"
	}

	typ := state.QType()

	requestCount.WithLabelValues(zone, net, fam).Inc()
	requestDuration.WithLabelValues(zone).Observe(float64(time.Since(start) / time.Millisecond))

	if state.Do() {
		requestDo.WithLabelValues(zone).Inc()
	}

	if _, known := monitorType[typ]; known {
		requestType.WithLabelValues(zone, dns.Type(typ).String()).Inc()
	} else {
		requestType.WithLabelValues(zone, other).Inc()
	}

	if typ == dns.TypeIXFR || typ == dns.TypeAXFR {
		responseTransferSize.WithLabelValues(zone, net).Observe(float64(size))
		requestTransferSize.WithLabelValues(zone, net).Observe(float64(state.Size()))
	} else {
		responseSize.WithLabelValues(zone, net).Observe(float64(size))
		requestSize.WithLabelValues(zone, net).Observe(float64(state.Size()))
	}

	responseRcode.WithLabelValues(zone, rcode).Inc()
}

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
}