Do not do ddns update if ip is same

1 files changed, 63 insertions, 0 deletions

diff --git a/dns/cilent.go b/dns/client.go
index 6efe1b5..f322b45 100644
--- a/dns/cilent.go
+++ b/dns/client.go
@@ -49,6 +49,37 @@ func (c *DNSClient) AXFR(zone *bind.Zone) (chan *dns.Envelope, error) {
         return t.In(m, fmt.Sprintf("%s:53", c.Server))
 }
 
+func (c *DNSClient) ReadRemoteZone(zone *bind.Zone) ([]RR, error) {
+        rrs := []RR{}
+        seenSoa := false
+
+        data, err := c.AXFR(zone)
+        if err != nil {
+                return nil, err
+        }
+
+        for rd := range data {
+                for _, r := range rd.RR {
+                        switch dr := FromDNS(r).(type) {
+                        case *SOA:
+                                // Transfers have 2 SOA records, exclude the last one
+                                if !seenSoa {
+                                        rrs = append(rrs, dr)
+                                        seenSoa = true
+                                }
+                        case RR:
+                                rrs = append(rrs, dr)
+                        default:
+                                // This should only be possible if we somehow are
+                                // missing generated DNS data types.
+                                return nil, fmt.Errorf("Invalid return type")
+                        }
+                }
+        }
+
+        return rrs, nil
+}
+
 func (c *DNSClient) StartUpdate(zone *bind.Zone) *DNSTransaction {
         m := &dns.Msg{}
         m.SetUpdate(zone.Name)
@@ -60,6 +91,18 @@ func (c *DNSClient) StartUpdate(zone *bind.Zone) *DNSTransaction {
         }
 }
 
+func (c *DNSClient) QueryRecursive(zone *bind.Zone, fqdn string, rtype uint16) *DNSTransaction {
+        m := &dns.Msg{}
+        m.RecursionDesired = true
+        m.SetQuestion(fqdn, rtype)
+
+        return &DNSTransaction{
+                zone: zone,
+                key:  zone.Keys()[0],
+                msg:  m,
+        }
+}
+
 func (c *DNSClient) SendUpdate(t *DNSTransaction) error {
         udp := &dns.Client{Net: "udp", TsigSecret: t.key.AsMap()}
         tcp := &dns.Client{Net: "tcp", TsigSecret: t.key.AsMap()}
@@ -79,3 +122,23 @@ func (c *DNSClient) SendUpdate(t *DNSTransaction) error {
 
         return nil
 }
+
+func (c *DNSClient) SendQuery(t *DNSTransaction) ([]dns.RR, error) {
+        udp := &dns.Client{Net: "udp", TsigSecret: t.key.AsMap()}
+        tcp := &dns.Client{Net: "tcp", TsigSecret: t.key.AsMap()}
+
+        t.msg.SetEdns0(4096, false)
+        t.key.Sign(t.msg)
+
+        in, _, err := udp.Exchange(t.msg, c.Server)
+        if in != nil && in.Truncated {
+                // If the TCP request succeeds, the err will reset to nil
+                in, _, err = tcp.Exchange(t.msg, c.Server)
+        }
+
+        if err != nil {
+                return nil, err
+        }
+
+        return in.Answer, nil
+}