Golang State.SizeAndDo方法代碼示例

func (c Chaos) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	state := middleware.State{W: w, Req: r}
	if state.QClass() != dns.ClassCHAOS || state.QType() != dns.TypeTXT {
		return c.Next.ServeDNS(ctx, w, r)
	}

	m := new(dns.Msg)
	m.SetReply(r)

	hdr := dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeTXT, Class: dns.ClassCHAOS, Ttl: 0}
	switch state.Name() {
	default:
		return c.Next.ServeDNS(ctx, w, r)
	case "authors.bind.":
		for a, _ := range c.Authors {
			m.Answer = append(m.Answer, &dns.TXT{Hdr: hdr, Txt: []string{trim(a)}})
		}
	case "version.bind.", "version.server.":
		m.Answer = []dns.RR{&dns.TXT{Hdr: hdr, Txt: []string{trim(c.Version)}}}
	case "hostname.bind.", "id.server.":
		hostname, err := os.Hostname()
		if err != nil {
			hostname = "localhost"
		}
		m.Answer = []dns.RR{&dns.TXT{Hdr: hdr, Txt: []string{trim(hostname)}}}
	}
	state.SizeAndDo(m)
	w.WriteMsg(m)
	return 0, nil
}

// 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 (l Logger) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	state := middleware.State{W: w, Req: r}
	for _, rule := range l.Rules {
		if middleware.Name(rule.NameScope).Matches(state.Name()) {
			responseRecorder := middleware.NewResponseRecorder(w)
			rcode, err := l.Next.ServeDNS(ctx, responseRecorder, r)

			if rcode > 0 {
				// There was an error up the chain, but no response has been written yet.
				// The error must be handled here so the log entry will record the response size.
				if l.ErrorFunc != nil {
					l.ErrorFunc(responseRecorder, r, rcode)
				} else {
					rc := middleware.RcodeToString(rcode)

					answer := new(dns.Msg)
					answer.SetRcode(r, rcode)
					state.SizeAndDo(answer)

					metrics.Report(state, metrics.Dropped, rc, answer.Len(), time.Now())
					w.WriteMsg(answer)
				}
				rcode = 0
			}
			rep := middleware.NewReplacer(r, responseRecorder, CommonLogEmptyValue)
			rule.Log.Println(rep.Replace(rule.Format))
			return rcode, err

		}
	}
	return l.Next.ServeDNS(ctx, w, r)
}

// NoData write a nodata response to the client.
func (k Kubernetes) Err(zone string, rcode int, state middleware.State) (int, error) {
	m := new(dns.Msg)
	m.SetRcode(state.Req, rcode)
	m.Ns = []dns.RR{k.SOA(zone, state)}
	state.SizeAndDo(m)
	state.W.WriteMsg(m)
	return rcode, nil
}

// DefaultErrorFunc responds to an DNS request with an error.
func DefaultErrorFunc(w dns.ResponseWriter, r *dns.Msg, rcode int) {
	state := middleware.State{W: w, Req: r}
	rc := middleware.RcodeToString(rcode)

	answer := new(dns.Msg)
	answer.SetRcode(r, rcode)
	state.SizeAndDo(answer)

	metrics.Report(state, metrics.Dropped, rc, answer.Len(), time.Now())
	w.WriteMsg(answer)
}

func (h ErrorHandler) recovery(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) {
	rec := recover()
	if rec == nil {
		return
	}

	state := middleware.State{W: w, Req: r}
	// Obtain source of panic
	// From: https://gist.github.com/swdunlop/9629168
	var name, file string // function name, file name
	var line int
	var pc [16]uintptr
	n := runtime.Callers(3, pc[:])
	for _, pc := range pc[:n] {
		fn := runtime.FuncForPC(pc)
		if fn == nil {
			continue
		}
		file, line = fn.FileLine(pc)
		name = fn.Name()
		if !strings.HasPrefix(name, "runtime.") {
			break
		}
	}

	// Trim file path
	delim := "/coredns/"
	pkgPathPos := strings.Index(file, delim)
	if pkgPathPos > -1 && len(file) > pkgPathPos+len(delim) {
		file = file[pkgPathPos+len(delim):]
	}

	panicMsg := fmt.Sprintf("%s [PANIC %s %s] %s:%d - %v", time.Now().Format(timeFormat), r.Question[0].Name, dns.Type(r.Question[0].Qtype), file, line, rec)
	if h.Debug {
		// Write error and stack trace to the response rather than to a log
		var stackBuf [4096]byte
		stack := stackBuf[:runtime.Stack(stackBuf[:], false)]
		answer := debugMsg(dns.RcodeServerFailure, r)
		// add stack buf in TXT, limited to 255 chars for now.
		txt, _ := dns.NewRR(". IN 0 TXT " + string(stack[:255]))
		answer.Answer = append(answer.Answer, txt)
		state.SizeAndDo(answer)
		w.WriteMsg(answer)
	} else {
		// Currently we don't use the function name, since file:line is more conventional
		h.Log.Printf(panicMsg)
	}
}

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)
}

func (s Stub) ServeDNS(ctx context.Context, w dns.ResponseWriter, req *dns.Msg) (int, error) {
	if hasStubEdns0(req) {
		log.Printf("[WARNING] Forwarding cycle detected, refusing msg: %s", req.Question[0].Name)
		return dns.RcodeRefused, errors.New("stub forward cycle")
	}
	req = addStubEdns0(req)
	proxy, ok := (*s.Etcd.Stubmap)[s.Zone]
	if !ok { // somebody made a mistake..
		return dns.RcodeServerFailure, nil
	}

	state := middleware.State{W: w, Req: req}
	m, e := proxy.Forward(state)
	if e != nil {
		return dns.RcodeServerFailure, e
	}
	m.RecursionAvailable, m.Compress = true, true
	state.SizeAndDo(m)
	w.WriteMsg(m)
	return dns.RcodeSuccess, nil
}

func (h ErrorHandler) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
	defer h.recovery(ctx, w, r)

	rcode, err := h.Next.ServeDNS(ctx, w, r)

	if err != nil {
		state := middleware.State{W: w, Req: r}
		errMsg := fmt.Sprintf("%s [ERROR %d %s %s] %v", time.Now().Format(timeFormat), rcode, state.Name(), state.Type(), err)

		if h.Debug {
			// Write error to response as a txt message instead of to log
			answer := debugMsg(rcode, r)
			txt, _ := dns.NewRR(". IN 0 TXT " + errMsg)
			answer.Answer = append(answer.Answer, txt)
			state.SizeAndDo(answer)
			w.WriteMsg(answer)
			return 0, err
		}
		h.Log.Println(errMsg)
	}

	return rcode, err
}

// Lookup will use name and type to forge a new message and will send that upstream. It will
// set any EDNS0 options correctly so that downstream will be able to process the reply.
// Lookup is not suitable for forwarding request. Ssee for that.
func (p Proxy) Lookup(state middleware.State, name string, tpe uint16) (*dns.Msg, error) {
	req := new(dns.Msg)
	req.SetQuestion(name, tpe)
	state.SizeAndDo(req)
	return p.lookup(state, req)
}

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
}