add PTR

record/rdata.go

@@ -312,6 +312,44 @@ func srvEqual(a, b []SRV) bool {
 	return true
 }
 
+type PTR struct {
+	Ttl  int    `json:"ttl"`
+	Name string `json:"name"`
+}
+
+// Equal determines if the record is equal
+func (a PTR) Equal(b PTR) bool {
+	return a.Ttl == b.Ttl && a.Name == b.Name
+}
+
+func (a PTR) TTL() (uint32, bool) {
+	if a.Ttl >= 0 {
+		return uint32(a.Ttl), true
+	}
+	return 0, false
+}
+
+func ptrEqual(a, b []PTR) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	c := 0
+	for _, ax := range a {
+		for _, bx := range b {
+			if ax.Name == bx.Name {
+				if !ax.Equal(bx) {
+					return false
+				}
+				c++
+			}
+		}
+	}
+	if len(a) != c {
+		return false
+	}
+	return true
+}
+
 type CAA struct {
 	Ttl   int    `json:"ttl"`
 	Flag  uint8  `json:"flag"`

record/record.go

@@ -34,6 +34,7 @@ type Records struct {
 	NS    []NS    `json:"NS,omitempty"`
 	MX    []MX    `json:"MX,omitempty"`
 	SRV   []SRV   `json:"SRV,omitempty"`
+	PTR   []PTR   `json:"PTR,omitempty"`
 	CAA   []CAA   `json:"CAA,omitempty"`
 }
 
@@ -140,6 +141,10 @@ func (z Zone) Equal(zone Zone) bool {
 			return false
 		}
 
+		if !ptrEqual(rec.PTR, r2.PTR) {
+			return false
+		}
+
 		if !caaEqual(rec.CAA, r2.CAA) {
 			return false
 		}
@@ -174,6 +179,8 @@ func (z *Zone) Add(loc string, record Record) {
 		z.addNs(loc, record.(NS))
 	case SRV:
 		z.addSrv(loc, record.(SRV))
+	case PTR:
+		z.addPtr(loc, record.(PTR))
 	case CAA:
 		z.addCaa(loc, record.(CAA))
 	default:
@@ -264,6 +271,17 @@ func (z *Zone) addSrv(loc string, rec SRV) {
 	z.Locations[loc] = r
 }
 
+func (z Zone) addPtr(loc string, rec PTR) {
+	r := z.getOrAddLocation(loc)
+	if r.PTR == nil {
+		r.PTR = make([]PTR, 1)
+		r.PTR[0] = rec
+	} else {
+		r.PTR = append(r.PTR, rec)
+	}
+	z.Locations[loc] = r
+}
+
 func (z *Zone) addCaa(loc string, rec CAA) {
 	r := z.getOrAddLocation(loc)
 	if r.CAA == nil {
@@ -359,6 +377,11 @@ func (z Zone) String() (str string) {
 				spacedLoc(loc, maxL), r.Ttl, r.Priority, r.Weight, r.Port, r.Target))
 			checkError(i, err)
 		}
+		for _, r := range z.Locations[k].PTR {
+			i, err = sb.WriteString(fmt.Sprintf("%s%d     IN     SRV     %s\n",
+				spacedLoc(loc, maxL), r.Ttl, r.Name))
+			checkError(i, err)
+		}
 		for _, r := range z.Locations[k].CAA {
 			i, err = sb.WriteString(fmt.Sprintf("%s%d     IN     CAA     %d %s %s\n",
 				spacedLoc(loc, maxL), r.Ttl, r.Flag, r.Tag, r.Value))

redis.go

@@ -221,6 +221,21 @@ func (redis *Redis) SRV(name string, z *record.Zone, record *record.Records, zon
 	return
 }
 
+func (redis *Redis) PTR(name string, z *record.Zone, record *record.Records, zones []string) (answers, extras []dns.RR) {
+	for _, ptr := range record.PTR {
+		if len(ptr.Name) == 0 {
+			continue
+		}
+		r := new(dns.PTR)
+		r.Hdr = dns.RR_Header{Name: dns.Fqdn(name), Rrtype: dns.TypePTR,
+			Class: dns.ClassINET, Ttl: redis.ttl(ptr.Ttl)}
+		r.Ptr = ptr.Name
+		answers = append(answers, r)
+		extras = append(extras, redis.getExtras(ptr.Name, z, zones)...)
+	}
+	return
+}
+
 func (redis *Redis) CAA(name string, _ *record.Zone, record *record.Records) (answers, extras []dns.RR) {
 	if record == nil {
 		return
@@ -283,6 +298,10 @@ func (redis *Redis) AXFR(z *record.Zone, zones []string) (records []dns.RR) {
 			answers = append(answers, as...)
 			extras = append(extras, xs...)
 
+			as, xs = redis.PTR(fqdnKey, z, zoneRecords, zones)
+			answers = append(answers, as...)
+			extras = append(extras, xs...)
+
 			as, xs = redis.TXT(fqdnKey, z, zoneRecords)
 			answers = append(answers, as...)
 			extras = append(extras, xs...)
@@ -331,7 +350,7 @@ func (redis *Redis) fillExtras(name string, z *record.Zone, location string) []d
 	)
 
 	zoneRecords = redis.LoadZoneRecords(location, z)
-   	zoneRecords.MakeFqdn(z.Name)
+	zoneRecords.MakeFqdn(z.Name)
 
 	if zoneRecords == nil {
 		return nil