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
}
func (e Etcd) 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, fmt.Errorf("can only deal with ClassINET")
}
name := state.Name()
if e.Debug {
if debug := isDebug(name); debug != "" {
e.debug = r.Question[0].Name
state.Clear()
state.Req.Question[0].Name = debug
}
}
// We need to check stubzones first, because we may get a request for a zone we
// are not auth. for *but* do have a stubzone forward for. If we do the stubzone
// handler will handle the request.
if e.Stubmap != nil && len(*e.Stubmap) > 0 {
for zone := range *e.Stubmap {
if middleware.Name(zone).Matches(name) {
stub := Stub{Etcd: e, Zone: zone}
return stub.ServeDNS(ctx, w, r)
}
}
}
zone := middleware.Zones(e.Zones).Matches(state.Name())
if zone == "" {
if e.Next == nil {
return dns.RcodeServerFailure, nil
}
return e.Next.ServeDNS(ctx, w, r)
}
var (
records, extra []dns.RR
debug []msg.Service
err error
)
switch state.Type() {
case "A":
records, debug, err = e.A(zone, state, nil)
case "AAAA":
records, debug, err = e.AAAA(zone, state, nil)
case "TXT":
records, debug, err = e.TXT(zone, state)
case "CNAME":
records, debug, err = e.CNAME(zone, state)
case "PTR":
records, debug, err = e.PTR(zone, state)
case "MX":
records, extra, debug, err = e.MX(zone, state)
case "SRV":
records, extra, debug, err = e.SRV(zone, state)
case "SOA":
records, debug, err = e.SOA(zone, state)
case "NS":
if state.Name() == zone {
records, extra, debug, err = e.NS(zone, state)
break
}
fallthrough
default:
// Do a fake A lookup, so we can distinguish between NODATA and NXDOMAIN
_, debug, err = e.A(zone, state, nil)
}
if e.debug != "" {
// Substitute this name with the original when we return the request.
state.Clear()
state.Req.Question[0].Name = e.debug
}
if isEtcdNameError(err) {
return e.Err(zone, dns.RcodeNameError, state, debug, err)
}
if err != nil {
return e.Err(zone, dns.RcodeServerFailure, state, debug, err)
}
if len(records) == 0 {
return e.Err(zone, dns.RcodeSuccess, state, debug, err)
}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
m.Answer = append(m.Answer, records...)
m.Extra = append(m.Extra, extra...)
if e.debug != "" {
m.Extra = append(m.Extra, servicesToTxt(debug)...)
}
m = dedup(m)
state.SizeAndDo(m)
m, _ = state.Scrub(m)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
log.Printf("[debug] here entering ServeDNS: ctx:%v dnsmsg:%v\n", ctx, r)
state := middleware.State{W: w, Req: r}
if state.QClass() != dns.ClassINET {
return dns.RcodeServerFailure, fmt.Errorf("can only deal with ClassINET")
}
// Check that query matches one of the zones served by this middleware,
// otherwise delegate to the next in the pipeline.
zone := middleware.Zones(k.Zones).Matches(state.Name())
if zone == "" {
if k.Next == nil {
return dns.RcodeServerFailure, nil
}
return k.Next.ServeDNS(ctx, w, r)
}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
var (
records, extra []dns.RR
err error
)
switch state.Type() {
case "A":
records, err = k.A(zone, state, nil)
case "AAAA":
records, err = k.AAAA(zone, state, nil)
case "TXT":
records, err = k.TXT(zone, state)
// TODO: change lookup to return appropriate error. Then add code below
// this switch to check for the error and return not implemented.
//return dns.RcodeNotImplemented, nil
case "CNAME":
records, err = k.CNAME(zone, state)
case "MX":
records, extra, err = k.MX(zone, state)
case "SRV":
records, extra, err = k.SRV(zone, state)
case "SOA":
records = []dns.RR{k.SOA(zone, state)}
case "NS":
if state.Name() == zone {
records, extra, err = k.NS(zone, state)
break
}
fallthrough
default:
// Do a fake A lookup, so we can distinguish betwen NODATA and NXDOMAIN
_, err = k.A(zone, state, nil)
}
if isKubernetesNameError(err) {
return k.Err(zone, dns.RcodeNameError, state)
}
if err != nil {
return dns.RcodeServerFailure, err
}
if len(records) == 0 {
return k.Err(zone, dns.RcodeSuccess, state)
}
m.Answer = append(m.Answer, records...)
m.Extra = append(m.Extra, extra...)
m = dedup(m)
state.SizeAndDo(m)
m, _ = state.Scrub(m)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
