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
}
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 (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
}
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
}