Return NOTIMP for some unimplemented query types, NXDOMAIN otherwise

weaveworks · Apr 23, 2015 · a99ae96 · a99ae96
1 parent 3ad186d
commit a99ae96
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Showing 3 changed files with 32 additions and 6 deletions.
diff --git a/nameserver/dns.go b/nameserver/dns.go
@@ -12,6 +12,11 @@ const (
 	maxUDPSize         = 65535
 )
 
+// query types we currently do not implement
+var notImplementedQTypes = map[uint16]struct{} {
+	dns.TypeANY: struct{}{},
+}
+
 func makeHeader(r *dns.Msg, q *dns.Question) *dns.RR_Header {
 	return &dns.RR_Header{
 		Name: q.Name, Rrtype: q.Qtype,

diff --git a/nameserver/server.go b/nameserver/server.go
@@ -240,15 +240,24 @@ func (s *DNSServer) queryHandler(proto dnsProtocol) dns.HandlerFunc {
 			return
 		}
 
-		// catch unsupported queries
-		if q.Qtype != dns.TypeA {
-			Debug.Printf("[dns msgid %d] Unsuported query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype])
+		// catch queries that are not implemented
+		if _, notImpl := notImplementedQTypes[q.Qtype]; notImpl {
+			Debug.Printf("[dns msgid %d] Unimplemented query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype])
 			m := makeDNSNotImplResponse(r)
 			s.cache.Put(r, m, negLocalTTL, 0, now)
 			w.WriteMsg(m)
 			return
 		}
 
+		// catch queries that will not be responsed here...
+		if q.Qtype != dns.TypeA {
+			Debug.Printf("[dns msgid %d] Unexpected query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype])
+			m := makeDNSFailResponse(r)
+			s.cache.Put(r, m, negLocalTTL, 0, now)
+			w.WriteMsg(m)
+			return
+		}
+
 		for _, lookup := range lookups {
 			if ip, err := lookup.LookupName(q.Name); err == nil {
 				m := makeAddressReply(r, &q, []net.IP{ip})
@@ -297,7 +306,16 @@ func (s *DNSServer) rdnsHandler(proto dnsProtocol) dns.HandlerFunc {
 			return
 		}
 
-		// catch unsupported queries
+		// catch queries that are not implemented
+		if _, notImpl := notImplementedQTypes[q.Qtype]; notImpl {
+			Debug.Printf("[dns msgid %d] Unimplemented query type %s", r.MsgHdr.Id, dns.TypeToString[q.Qtype])
+			m := makeDNSNotImplResponse(r)
+			s.cache.Put(r, m, negLocalTTL, 0, now)
+			w.WriteMsg(m)
+			return
+		}
+
+		// catch queries that will not be responsed here...
 		if q.Qtype != dns.TypePTR {
 			Warning.Printf("[dns msgid %d] Unexpected reverse query type %s: %+v",
 				r.MsgHdr.Id, dns.TypeToString[q.Qtype], q)

diff --git a/nameserver/server_test.go b/nameserver/server_test.go
@@ -100,8 +100,11 @@ func TestUDPDNSServer(t *testing.T) {
 
 	assertExchange(t, testRDNSfail, dns.TypePTR, 0, 0, dns.RcodeNameError)
 
-	// This should fail because we don't handle MX records
-	assertExchange(t, successTestName, dns.TypeMX, 0, 0, dns.RcodeNotImplemented)
+	// This should fail because we don't have information about MX records
+	assertExchange(t, successTestName, dns.TypeMX, 0, 0, dns.RcodeNameError)
+
+	// This should fail because we don't support SOA records
+	assertExchange(t, successTestName, dns.TypeANY, 0, 0, dns.RcodeNotImplemented)
 
 	// This non-local query for an MX record should succeed by being
 	// passed on to the fallback server