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)}}}
}
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,
}
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:
str, weight := getStringWeight(records[rType][i].([]interface{}))
ip := str
record.Weight = weight
switch dnsType {
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.TypeToString[qtype], req.MsgHdr.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)
realIp, _, _ := net.SplitHostPort(w.RemoteAddr().String())
z.Metrics.ClientStats.Add(realIp)
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 len(ip) == 0 { // no edns subnet
ip = net.ParseIP(realIp)
}
targets, netmask := z.Options.Targeting.GetTargets(ip)
m := new(dns.Msg)
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 {
firstLabel := (strings.Split(label, "."))[0]
if 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 := record.RR
rr.Header().Name = req.Question[0].Name
rrs = append(rrs, rr)
}
m.Answer = rrs
}
if len(m.Answer) == 0 {
m.Ns = append(m.Ns, z.SoaRR())
}
logPrintln(m)
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 serve(w dns.ResponseWriter, req *dns.Msg, z *Zone) {
qtype := req.Question[0].Qtype
logPrintf("[zone %s] incoming %s %s (id %d) from %s\n", z.Origin, req.Question[0].Name,
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)
}
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 len(ip) == 0 { // no edns subnet
ip = realIP
}
targets, netmask := z.Options.Targeting.GetTargets(ip)
m := new(dns.Msg)
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 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)
t := time.Now()
logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)
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)
t := time.Now()
logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)
return
}
// return NXDOMAIN
m.SetRcode(req, dns.RcodeNameError)
m.Authoritative = true
m.Ns = []dns.RR{z.SoaRR()}
w.WriteMsg(m)
t := time.Now()
logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)
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 = req.Question[0].Name
rrs = append(rrs, rr)
}
m.Answer = rrs
}
if len(m.Answer) == 0 {
m.Ns = append(m.Ns, z.SoaRR())
} else {
if z.Labels[label] != nil {
z.Labels[label].Hits++
logPrintln("*********** ", z.Labels[label].Hits)
}
}
//logPrintln(m)
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)
}
t := time.Now()
logAccessPrintf("%s [%02d/%02d/%04d:%02d:%02d:%02d] %s %s %s\n", w.RemoteAddr(), t.Day(), t.Month(), t.Year(), t.Hour(), t.Minute(), t.Second(), req.Question[0].Name, dns.TypeToString[qtype], m.Answer)
return
}