func dnsAppend(q dns.Question, m *dns.Msg, rr dns.RR) {
hdr := dns.RR_Header{Name: q.Name, Class: q.Qclass, Ttl: 0}
if rrS, ok := rr.(*dns.A); ok {
hdr.Rrtype = dns.TypeA
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.AAAA); ok {
hdr.Rrtype = dns.TypeAAAA
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.CNAME); ok {
hdr.Rrtype = dns.TypeCNAME
rrS.Hdr = hdr
} else if rrS, ok := rr.(*dns.TXT); ok {
hdr.Rrtype = dns.TypeTXT
rrS.Hdr = hdr
} else {
log.Printf("error: unknown dnsAppend RR type: %+v\n", rr)
return
}
if q.Qtype == dns.TypeANY || q.Qtype == rr.Header().Rrtype {
m.Answer = append(m.Answer, rr)
} else {
m.Extra = append(m.Extra, rr)
}
}
func statusRR(z *Zone) []dns.RR {
h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
h.Name = "_status." + z.Origin + "."
status := map[string]string{"v": VERSION, "id": serverId}
hostname, err := os.Hostname()
if err == nil {
status["h"] = hostname
}
status["up"] = strconv.Itoa(int(time.Since(timeStarted).Seconds()))
status["qs"] = strconv.FormatUint(qCounter, 10)
js, err := json.Marshal(status)
return []dns.RR{&dns.RR_TXT{Hdr: h, Txt: []string{string(js)}}}
}
func (s *Service) answer(q dns.Question) (answers []dns.RR) {
name := strings.TrimSuffix(q.Name, s.Config.Domain)
if name != "" && strings.HasSuffix(name, ".") {
name = name[0 : len(name)-1]
}
instances := s.AWSService.GetEC2FromName(name)
for _, inst := range instances {
var target string
ttl := s.Config.Ttl
hdr := dns.RR_Header{
Name: q.Name,
Class: dns.ClassINET,
Rrtype: q.Qtype,
Ttl: ttl,
}
if inst.PubicDNS != "" {
hdr.Rrtype = dns.TypeCNAME
target = inst.PubicDNS
if !strings.HasSuffix(target, ".") {
target += "."
}
} else if q.Qtype == dns.TypeA {
target = inst.PublicIP
if target == "" {
target = inst.PrivateIP
}
}
if target == "" {
continue
}
if hdr.Rrtype == dns.TypeCNAME {
answers = append(answers, &dns.CNAME{
Hdr: hdr,
Target: target,
})
} else if hdr.Rrtype == dns.TypeA {
answers = append(answers, &dns.A{
Hdr: hdr,
A: net.ParseIP(target),
})
}
}
return answers
}
func statusRR(label string) []dns.RR {
h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
h.Name = label
status := map[string]string{"v": VERSION, "id": serverID}
hostname, err := os.Hostname()
if err == nil {
status["h"] = hostname
}
qCounter := metrics.Get("queries").(metrics.Meter)
status["up"] = strconv.Itoa(int(time.Since(timeStarted).Seconds()))
status["qs"] = strconv.FormatInt(qCounter.Count(), 10)
status["qps1"] = fmt.Sprintf("%.4f", qCounter.Rate1())
js, err := json.Marshal(status)
return []dns.RR{&dns.TXT{Hdr: h, Txt: []string{string(js)}}}
}
// Resolve wraps Unbound's ub_resolve.
func (u *Unbound) Resolve(name string, rrtype, rrclass uint16) (*Result, error) {
res := C.new_ub_result()
r := new(Result)
defer C.ub_resolve_free(res)
i := C.ub_resolve(u.ctx, C.CString(name), C.int(rrtype), C.int(rrclass), &res)
err := newError(int(i))
if err != nil {
return nil, err
}
r.Qname = C.GoString(res.qname)
r.Qtype = uint16(res.qtype)
r.Qclass = uint16(res.qclass)
r.CanonName = C.GoString(res.canonname)
r.Rcode = int(res.rcode)
r.AnswerPacket = new(dns.Msg)
r.AnswerPacket.Unpack(C.GoBytes(res.answer_packet, res.answer_len)) // Should always work
r.HaveData = res.havedata == 1
r.NxDomain = res.nxdomain == 1
r.Secure = res.secure == 1
r.Bogus = res.bogus == 1
r.WhyBogus = C.GoString(res.why_bogus)
// Re-create the RRs
var h dns.RR_Header
h.Name = r.Qname
h.Rrtype = r.Qtype
h.Class = r.Qclass
h.Ttl = 0
r.Data = make([][]byte, 0)
r.Rr = make([]dns.RR, 0)
j := 0
if r.HaveData {
b := C.GoBytes(unsafe.Pointer(C.array_elem_char(res.data, C.int(j))), C.array_elem_int(res.len, C.int(j)))
for len(b) != 0 {
// Create the RR
h.Rdlength = uint16(len(b))
msg := make([]byte, 20+len(h.Name)) // Long enough
off, _ := dns.PackStruct(&h, msg, 0)
msg = msg[:off]
rrbuf := append(msg, b...)
rr, _, err := dns.UnpackRR(rrbuf, 0)
if err == nil {
r.Rr = append(r.Rr, rr)
}
r.Data = append(r.Data, b)
j++
b = C.GoBytes(unsafe.Pointer(C.array_elem_char(res.data, C.int(j))), C.array_elem_int(res.len, C.int(j)))
}
}
return r, err
}
func (srv *Server) serve(w dns.ResponseWriter, req *dns.Msg, z *Zone) {
qname := req.Question[0].Name
qtype := req.Question[0].Qtype
var qle *querylog.Entry
if srv.queryLogger != nil {
qle = &querylog.Entry{
Time: time.Now().UnixNano(),
Origin: z.Origin,
Name: qname,
Qtype: qtype,
}
defer srv.queryLogger.Write(qle)
}
logPrintf("[zone %s] incoming %s %s (id %d) from %s\n", z.Origin, qname,
dns.TypeToString[qtype], req.Id, w.RemoteAddr())
// Global meter
metrics.Get("queries").(metrics.Meter).Mark(1)
// Zone meter
z.Metrics.Queries.Mark(1)
logPrintln("Got request", req)
label := getQuestionName(z, req)
z.Metrics.LabelStats.Add(label)
// IP that's talking to us (not EDNS CLIENT SUBNET)
var realIP net.IP
if addr, ok := w.RemoteAddr().(*net.UDPAddr); ok {
realIP = make(net.IP, len(addr.IP))
copy(realIP, addr.IP)
} else if addr, ok := w.RemoteAddr().(*net.TCPAddr); ok {
realIP = make(net.IP, len(addr.IP))
copy(realIP, addr.IP)
}
if qle != nil {
qle.RemoteAddr = realIP.String()
}
z.Metrics.ClientStats.Add(realIP.String())
var ip net.IP // EDNS or real IP
var edns *dns.EDNS0_SUBNET
var opt_rr *dns.OPT
for _, extra := range req.Extra {
switch extra.(type) {
case *dns.OPT:
for _, o := range extra.(*dns.OPT).Option {
opt_rr = extra.(*dns.OPT)
switch e := o.(type) {
case *dns.EDNS0_NSID:
// do stuff with e.Nsid
case *dns.EDNS0_SUBNET:
z.Metrics.EdnsQueries.Mark(1)
logPrintln("Got edns", e.Address, e.Family, e.SourceNetmask, e.SourceScope)
if e.Address != nil {
edns = e
ip = e.Address
if qle != nil {
qle.HasECS = true
qle.ClientAddr = fmt.Sprintf("%s/%d", ip, e.SourceNetmask)
}
}
}
}
}
}
if len(ip) == 0 { // no edns subnet
ip = realIP
if qle != nil {
qle.ClientAddr = fmt.Sprintf("%s/%d", ip, len(ip)*8)
}
}
targets, netmask := z.Options.Targeting.GetTargets(ip)
if qle != nil {
qle.Targets = targets
}
m := new(dns.Msg)
if qle != nil {
defer func() {
qle.Rcode = m.Rcode
qle.Answers = len(m.Answer)
}()
}
m.SetReply(req)
if e := m.IsEdns0(); e != nil {
m.SetEdns0(4096, e.Do())
}
m.Authoritative = true
// TODO: set scope to 0 if there are no alternate responses
if edns != nil {
if edns.Family != 0 {
if netmask < 16 {
netmask = 16
}
edns.SourceScope = uint8(netmask)
m.Extra = append(m.Extra, opt_rr)
}
}
labels, labelQtype := z.findLabels(label, targets, qTypes{dns.TypeMF, dns.TypeCNAME, qtype})
if labelQtype == 0 {
labelQtype = qtype
}
if labels == nil {
permitDebug := !*flagPrivateDebug || (realIP != nil && realIP.IsLoopback())
firstLabel := (strings.Split(label, "."))[0]
if qle != nil {
qle.LabelName = firstLabel
}
if permitDebug && firstLabel == "_status" {
if qtype == dns.TypeANY || qtype == dns.TypeTXT {
m.Answer = statusRR(label + "." + z.Origin + ".")
} else {
m.Ns = append(m.Ns, z.SoaRR())
}
m.Authoritative = true
w.WriteMsg(m)
return
}
if firstLabel == "_country" {
if qtype == dns.TypeANY || qtype == dns.TypeTXT {
h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
h.Name = label + "." + z.Origin + "."
txt := []string{
w.RemoteAddr().String(),
ip.String(),
}
targets, netmask := z.Options.Targeting.GetTargets(ip)
txt = append(txt, strings.Join(targets, " "))
txt = append(txt, fmt.Sprintf("/%d", netmask), serverID, serverIP)
m.Answer = []dns.RR{&dns.TXT{Hdr: h,
Txt: txt,
}}
} else {
m.Ns = append(m.Ns, z.SoaRR())
}
m.Authoritative = true
w.WriteMsg(m)
return
}
// return NXDOMAIN
m.SetRcode(req, dns.RcodeNameError)
m.Authoritative = true
m.Ns = []dns.RR{z.SoaRR()}
w.WriteMsg(m)
return
}
if servers := labels.Picker(labelQtype, labels.MaxHosts); servers != nil {
var rrs []dns.RR
for _, record := range servers {
rr := dns.Copy(record.RR)
rr.Header().Name = qname
rrs = append(rrs, rr)
}
m.Answer = rrs
}
if len(m.Answer) == 0 {
// Return a SOA so the NOERROR answer gets cached
m.Ns = append(m.Ns, z.SoaRR())
}
logPrintln(m)
if qle != nil {
qle.LabelName = labels.Label
qle.Answers = len(m.Answer)
qle.Rcode = m.Rcode
}
err := w.WriteMsg(m)
if err != nil {
// if Pack'ing fails the Write fails. Return SERVFAIL.
log.Println("Error writing packet", m)
dns.HandleFailed(w, req)
}
return
}
func setupZoneData(data map[string]interface{}, Zone *Zone) {
recordTypes := map[string]uint16{
"a": dns.TypeA,
"aaaa": dns.TypeAAAA,
"ns": dns.TypeNS,
"cname": dns.TypeCNAME,
"alias": dns.TypeMF,
}
for dk, dv_inter := range data {
dv := dv_inter.(map[string]interface{})
//log.Printf("K %s V %s TYPE-V %T\n", dk, dv, dv)
dk = strings.ToLower(dk)
Zone.Labels[dk] = new(Label)
label := Zone.Labels[dk]
label.Label = dk
label.Ttl = Zone.Options.Ttl
label.MaxHosts = Zone.Options.MaxHosts
if ttl, ok := dv["ttl"]; ok {
label.Ttl = valueToInt(ttl)
}
if maxHosts, ok := dv["max_hosts"]; ok {
label.MaxHosts = valueToInt(maxHosts)
}
for rType, dnsType := range recordTypes {
rdata := dv[rType]
if rdata == nil {
//log.Printf("No %s records for label %s\n", rType, dk)
continue
}
//log.Printf("rdata %s TYPE-R %T\n", rdata, rdata)
records := make(map[string][]interface{})
switch rdata.(type) {
case map[string]interface{}:
// Handle NS map syntax, map[ns2.example.net:<nil> ns1.example.net:<nil>]
tmp := make([]interface{}, 0)
for rdata_k, rdata_v := range rdata.(map[string]interface{}) {
if rdata_v == nil {
rdata_v = ""
}
tmp = append(tmp, []string{rdata_k, rdata_v.(string)})
}
records[rType] = tmp
case string:
// CNAME and alias
tmp := make([]interface{}, 1)
tmp[0] = rdata.(string)
records[rType] = tmp
default:
records[rType] = rdata.([]interface{})
}
//log.Printf("RECORDS %s TYPE-REC %T\n", Records, Records)
if label.Records == nil {
label.Records = make(map[uint16]Records)
label.Weight = make(map[uint16]int)
}
label.Records[dnsType] = make(Records, len(records[rType]))
for i := 0; i < len(records[rType]); i++ {
//log.Printf("RT %T %#v\n", records[rType][i], records[rType][i])
record := new(Record)
var h dns.RR_Header
// log.Println("TTL OPTIONS", Zone.Options.Ttl)
h.Ttl = uint32(label.Ttl)
h.Class = dns.ClassINET
h.Rrtype = dnsType
h.Name = label.Label + "." + Zone.Origin + "."
switch dnsType {
case dns.TypeA, dns.TypeAAAA:
rec := records[rType][i].([]interface{})
ip := rec[0].(string)
var err error
switch rec[1].(type) {
case string:
record.Weight, err = strconv.Atoi(rec[1].(string))
if err != nil {
panic("Error converting weight to integer")
}
label.Weight[dnsType] += record.Weight
case float64:
record.Weight = int(rec[1].(float64))
label.Weight[dnsType] += record.Weight
}
switch dnsType {
case dns.TypeA:
if x := net.ParseIP(ip); x != nil {
record.RR = &dns.RR_A{Hdr: h, A: x}
break
}
panic("Bad A record")
case dns.TypeAAAA:
if x := net.ParseIP(ip); x != nil {
record.RR = &dns.RR_AAAA{Hdr: h, AAAA: x}
break
}
panic("Bad AAAA record")
}
case dns.TypeCNAME:
rec := records[rType][i]
record.RR = &dns.RR_CNAME{Hdr: h, Target: dns.Fqdn(rec.(string))}
case dns.TypeMF:
rec := records[rType][i]
// MF records (how we store aliases) are not FQDNs
record.RR = &dns.RR_MF{Hdr: h, Mf: rec.(string)}
case dns.TypeNS:
rec := records[rType][i]
if h.Ttl < 86400 {
h.Ttl = 86400
}
var ns string
switch rec.(type) {
case string:
ns = rec.(string)
case []string:
recl := rec.([]string)
ns = recl[0]
if len(recl[1]) > 0 {
log.Println("NS records with names syntax not supported")
}
default:
log.Printf("Data: %T %#v\n", rec, rec)
panic("Unrecognized NS format/syntax")
}
rr := &dns.RR_NS{Hdr: h, Ns: dns.Fqdn(ns)}
record.RR = rr
default:
log.Println("type:", rType)
panic("Don't know how to handle this type")
}
if record.RR == nil {
panic("record.RR is nil")
}
label.Records[dnsType][i] = *record
}
if label.Weight[dnsType] > 0 {
sort.Sort(RecordsByWeight{label.Records[dnsType]})
}
}
}
setupSOA(Zone)
//log.Println(Zones[k])
}
func setupZoneData(data map[string]interface{}, Zone *Zone) {
recordTypes := map[string]uint16{
"a": dns.TypeA,
"aaaa": dns.TypeAAAA,
"alias": dns.TypeMF,
"cname": dns.TypeCNAME,
"mx": dns.TypeMX,
"ns": dns.TypeNS,
"txt": dns.TypeTXT,
"spf": dns.TypeSPF,
"srv": dns.TypeSRV,
"ptr": dns.TypePTR,
}
for dk, dv_inter := range data {
dv := dv_inter.(map[string]interface{})
//log.Printf("K %s V %s TYPE-V %T\n", dk, dv, dv)
label := Zone.AddLabel(dk)
for rType, rdata := range dv {
switch rType {
case "max_hosts":
label.MaxHosts = valueToInt(rdata)
continue
case "ttl":
label.Ttl = valueToInt(rdata)
continue
}
dnsType, ok := recordTypes[rType]
if !ok {
log.Printf("Unsupported record type '%s'\n", rType)
continue
}
if rdata == nil {
//log.Printf("No %s records for label %s\n", rType, dk)
continue
}
//log.Printf("rdata %s TYPE-R %T\n", rdata, rdata)
records := make(map[string][]interface{})
switch rdata.(type) {
case map[string]interface{}:
// Handle NS map syntax, map[ns2.example.net:<nil> ns1.example.net:<nil>]
tmp := make([]interface{}, 0)
for rdataK, rdataV := range rdata.(map[string]interface{}) {
if rdataV == nil {
rdataV = ""
}
tmp = append(tmp, []string{rdataK, rdataV.(string)})
}
records[rType] = tmp
case string:
// CNAME and alias
tmp := make([]interface{}, 1)
tmp[0] = rdata.(string)
records[rType] = tmp
default:
records[rType] = rdata.([]interface{})
}
//log.Printf("RECORDS %s TYPE-REC %T\n", Records, Records)
label.Records[dnsType] = make(Records, len(records[rType]))
for i := 0; i < len(records[rType]); i++ {
//log.Printf("RT %T %#v\n", records[rType][i], records[rType][i])
record := new(Record)
var h dns.RR_Header
h.Class = dns.ClassINET
h.Rrtype = dnsType
// We add the TTL as a last pass because we might not have
// processed it yet when we process the record data.
switch len(label.Label) {
case 0:
h.Name = Zone.Origin + "."
default:
h.Name = label.Label + "." + Zone.Origin + "."
}
switch dnsType {
case dns.TypeA, dns.TypeAAAA, dns.TypePTR:
str, weight := getStringWeight(records[rType][i].([]interface{}))
ip := str
record.Weight = weight
switch dnsType {
case dns.TypePTR:
record.RR = &dns.PTR{Hdr: h, Ptr: ip}
break
case dns.TypeA:
if x := net.ParseIP(ip); x != nil {
record.RR = &dns.A{Hdr: h, A: x}
break
}
panic(fmt.Errorf("Bad A record %s for %s", ip, dk))
case dns.TypeAAAA:
if x := net.ParseIP(ip); x != nil {
record.RR = &dns.AAAA{Hdr: h, AAAA: x}
break
}
panic(fmt.Errorf("Bad AAAA record %s for %s", ip, dk))
}
case dns.TypeMX:
rec := records[rType][i].(map[string]interface{})
pref := uint16(0)
mx := rec["mx"].(string)
if !strings.HasSuffix(mx, ".") {
mx = mx + "."
}
if rec["weight"] != nil {
record.Weight = valueToInt(rec["weight"])
}
if rec["preference"] != nil {
pref = uint16(valueToInt(rec["preference"]))
}
record.RR = &dns.MX{
Hdr: h,
Mx: mx,
Preference: pref}
case dns.TypeSRV:
rec := records[rType][i].(map[string]interface{})
priority := uint16(0)
srv_weight := uint16(0)
port := uint16(0)
target := rec["target"].(string)
if !dns.IsFqdn(target) {
target = target + "." + Zone.Origin
}
if rec["srv_weight"] != nil {
srv_weight = uint16(valueToInt(rec["srv_weight"]))
}
if rec["port"] != nil {
port = uint16(valueToInt(rec["port"]))
}
if rec["priority"] != nil {
priority = uint16(valueToInt(rec["priority"]))
}
record.RR = &dns.SRV{
Hdr: h,
Priority: priority,
Weight: srv_weight,
Port: port,
Target: target}
case dns.TypeCNAME:
rec := records[rType][i]
var target string
var weight int
switch rec.(type) {
case string:
target = rec.(string)
case []interface{}:
target, weight = getStringWeight(rec.([]interface{}))
}
if !dns.IsFqdn(target) {
target = target + "." + Zone.Origin
}
record.Weight = weight
record.RR = &dns.CNAME{Hdr: h, Target: dns.Fqdn(target)}
case dns.TypeMF:
rec := records[rType][i]
// MF records (how we store aliases) are not FQDNs
record.RR = &dns.MF{Hdr: h, Mf: rec.(string)}
case dns.TypeNS:
rec := records[rType][i]
if h.Ttl < 86400 {
h.Ttl = 86400
}
var ns string
switch rec.(type) {
case string:
ns = rec.(string)
case []string:
recl := rec.([]string)
ns = recl[0]
if len(recl[1]) > 0 {
log.Println("NS records with names syntax not supported")
}
default:
log.Printf("Data: %T %#v\n", rec, rec)
panic("Unrecognized NS format/syntax")
}
rr := &dns.NS{Hdr: h, Ns: dns.Fqdn(ns)}
record.RR = rr
case dns.TypeTXT:
rec := records[rType][i]
var txt string
switch rec.(type) {
case string:
txt = rec.(string)
case map[string]interface{}:
recmap := rec.(map[string]interface{})
if weight, ok := recmap["weight"]; ok {
record.Weight = valueToInt(weight)
}
if t, ok := recmap["txt"]; ok {
txt = t.(string)
}
}
if len(txt) > 0 {
rr := &dns.TXT{Hdr: h, Txt: []string{txt}}
record.RR = rr
} else {
log.Printf("Zero length txt record for '%s' in '%s'\n", label.Label, Zone.Origin)
continue
}
// Initial SPF support added here, cribbed from the TypeTXT case definition - SPF records should be handled identically
case dns.TypeSPF:
rec := records[rType][i]
var spf string
switch rec.(type) {
case string:
spf = rec.(string)
case map[string]interface{}:
recmap := rec.(map[string]interface{})
if weight, ok := recmap["weight"]; ok {
record.Weight = valueToInt(weight)
}
if t, ok := recmap["spf"]; ok {
spf = t.(string)
}
}
if len(spf) > 0 {
rr := &dns.SPF{Hdr: h, Txt: []string{spf}}
record.RR = rr
} else {
log.Printf("Zero length SPF record for '%s' in '%s'\n", label.Label, Zone.Origin)
continue
}
default:
log.Println("type:", rType)
panic("Don't know how to handle this type")
}
if record.RR == nil {
panic("record.RR is nil")
}
label.Weight[dnsType] += record.Weight
label.Records[dnsType][i] = *record
}
if label.Weight[dnsType] > 0 {
sort.Sort(RecordsByWeight{label.Records[dnsType]})
}
}
}
// loop over exisiting labels, create zone records for missing sub-domains
// and set TTLs
for k := range Zone.Labels {
if strings.Contains(k, ".") {
subLabels := strings.Split(k, ".")
for i := 1; i < len(subLabels); i++ {
subSubLabel := strings.Join(subLabels[i:], ".")
if _, ok := Zone.Labels[subSubLabel]; !ok {
Zone.AddLabel(subSubLabel)
}
}
}
if Zone.Labels[k].Ttl > 0 {
for _, records := range Zone.Labels[k].Records {
for _, r := range records {
r.RR.Header().Ttl = uint32(Zone.Labels[k].Ttl)
}
}
}
}
setupSOA(Zone)
//log.Println(Zones[k])
}
func serve(w dns.ResponseWriter, req *dns.Msg, z *Zone) {
qtype := req.Question[0].Qtype
logPrintf("[zone %s] incoming %s %s %d from %s\n", z.Origin, req.Question[0].Name,
dns.Rr_str[qtype], req.MsgHdr.Id, w.RemoteAddr())
// is this safe/atomic or does it need to go through a channel?
qCounter++
logPrintln("Got request", req)
label := getQuestionName(z, req)
var country string
if geoIP != nil {
ip, _, _ := net.SplitHostPort(w.RemoteAddr().String())
country = strings.ToLower(geoIP.GetCountry(ip))
logPrintln("Country:", ip, country)
}
m := new(dns.Msg)
m.SetReply(req)
if e := m.IsEdns0(); e != nil {
m.SetEdns0(4096, e.Do())
}
m.Authoritative = true
// TODO(ask) Fix the findLabels API to make this work better
if alias := z.findLabels(label, "", dns.TypeMF); alias != nil &&
alias.Records[dns.TypeMF] != nil {
// We found an alias record, so pretend the question was for that name instead
label = alias.firstRR(dns.TypeMF).(*dns.RR_MF).Mf
}
labels := z.findLabels(label, country, qtype)
if labels == nil {
if label == "_status" && (qtype == dns.TypeANY || qtype == dns.TypeTXT) {
m.Answer = statusRR(z)
m.Authoritative = true
w.Write(m)
return
}
if label == "_country" && (qtype == dns.TypeANY || qtype == dns.TypeTXT) {
h := dns.RR_Header{Ttl: 1, Class: dns.ClassINET, Rrtype: dns.TypeTXT}
h.Name = "_country." + z.Origin + "."
m.Answer = []dns.RR{&dns.RR_TXT{Hdr: h,
Txt: []string{
w.RemoteAddr().String(),
string(country),
string(countries.CountryContinent[country]),
},
}}
m.Authoritative = true
w.Write(m)
return
}
// return NXDOMAIN
m.SetRcode(req, dns.RcodeNameError)
m.Authoritative = true
m.Ns = []dns.RR{z.SoaRR()}
w.Write(m)
return
}
if servers := labels.Picker(qtype, labels.MaxHosts); servers != nil {
var rrs []dns.RR
for _, record := range servers {
rr := record.RR
rr.Header().Name = req.Question[0].Name
rrs = append(rrs, rr)
}
m.Answer = rrs
}
if len(m.Answer) == 0 {
if labels := z.Labels[label]; labels != nil {
if _, ok := labels.Records[dns.TypeCNAME]; ok {
cname := labels.firstRR(dns.TypeCNAME)
m.Answer = append(m.Answer, cname)
}
} else {
m.Ns = append(m.Ns, z.SoaRR())
}
}
logPrintln(m)
err := w.Write(m)
if err != nil {
// if Pack'ing fails the Write fails. Return SERVFAIL.
log.Println("Error writing packet", m)
dns.HandleFailed(w, req)
}
return
}