correct k8s name parsing response codes (#493)

middleware/kubernetes/kubernetes.go

@@ -225,7 +225,10 @@ func (k *Kubernetes) parseRequest(lowerCasedName, qtype string) (r recordRequest
 	}
 
 	offset := 0
-	if len(segs) == 5 {
+	if qtype == "SRV" {
+		if len(segs) != 5 {
+			return r, errInvalidRequest
+		}
 		// This is a SRV style request, get first two elements as port and
 		// protocol, stripping leading underscores if present.
 		if segs[0][0] == '_' {
@@ -233,38 +236,29 @@ func (k *Kubernetes) parseRequest(lowerCasedName, qtype string) (r recordRequest
 		} else {
 			r.port = segs[0]
 			if !symbolContainsWildcard(r.port) {
-				return r, errors.New("srv port must start with an underscore or be a wildcard")
+				return r, errInvalidRequest
 			}
 		}
 		if segs[1][0] == '_' {
 			r.protocol = segs[1][1:]
 			if r.protocol != "tcp" && r.protocol != "udp" {
-				return r, errors.New("invalid srv protocol: " + r.protocol)
+				return r, errInvalidRequest
 			}
 		} else {
 			r.protocol = segs[1]
 			if !symbolContainsWildcard(r.protocol) {
-				return r, errors.New("srv protocol must start with an underscore or be a wildcard")
-			}
+				return r, errInvalidRequest
 			}
-		offset = 2
-	} else if len(segs) == 4 {
-		// This is an endpoint A style request. Get first element as endpoint.
-		r.endpoint = segs[0]
-		offset = 1
 		}
-
-	// SRV requests require a port and protocol
-	if qtype == "SRV" {
 		if r.port == "" || r.protocol == "" {
-			return r, errors.New("invalid srv request")
-		}
+			return r, errInvalidRequest
 		}
-	// A requests cannot have port/protocol
-	if qtype == "A" {
-		if r.port != "" && r.protocol != "" {
-			return r, errors.New("invalid a request")
+		offset = 2
 	}
+	if qtype == "A" && len(segs) == 4 {
+		// This is an endpoint A record request. Get first element as endpoint.
+		r.endpoint = segs[0]
+		offset = 1
 	}
 
 	if len(segs) == (offset + 3) {
@@ -280,7 +274,7 @@ func (k *Kubernetes) parseRequest(lowerCasedName, qtype string) (r recordRequest
 		return r, nil
 	}
 
-	return r, errors.New("invalid request")
+	return r, errInvalidRequest
 
 }
 

test/kubernetes_test.go

@@ -181,17 +181,17 @@ var dnsTestCases = []test.Case{
 	},
 	{
 		Qname: "*.svc-1-a.test-1.svc.cluster.local.", Qtype: dns.TypeSRV,
-		Rcode:  dns.RcodeServerFailure,
+		Rcode:  dns.RcodeNameError,
 		Answer: []dns.RR{},
 	},
 	{
 		Qname: "*._not-udp-or-tcp.svc-1-a.test-1.svc.cluster.local.", Qtype: dns.TypeSRV,
-		Rcode:  dns.RcodeServerFailure,
+		Rcode:  dns.RcodeNameError,
 		Answer: []dns.RR{},
 	},
 	{
 		Qname: "svc-1-a.test-1.svc.cluster.local.", Qtype: dns.TypeSRV,
-		Rcode:  dns.RcodeServerFailure,
+		Rcode:  dns.RcodeNameError,
 		Answer: []dns.RR{},
 	},
 	{