log output upstream dns server reply code

server.go

@@ -105,40 +105,49 @@ func handleRoot(w dns.ResponseWriter, r *dns.Msg) {
 		done = 0
 		for _, sv := range Servers {
 			if sv.match(domain) {
-				logger.Debug("%s query %s %s %s, forward to %s:%s\n",
+
+				res, err = sv.query(r)
+				if err != nil {
+					logger.Error("%s", err)
+					continue
+				}
+
+				logger.Debug("%s query %s %s %s, forward to %s:%s, %s\n",
 					w.RemoteAddr(),
 					domain,
 					dns.ClassToString[r.Question[0].Qclass],
 					dns.TypeToString[r.Question[0].Qtype],
-					sv.Proto, sv.Addr)
+					sv.Proto, sv.Addr,
-				res, err = sv.query(r)
+					dns.RcodeToString[res.Rcode],
-				if err == nil {
+				)
-					if !in_blacklist(res) && res.Rcode != dns.RcodeServerFailure {
+
-						w.WriteMsg(res)
+				if res.Rcode != dns.RcodeServerFailure && !in_blacklist(res) {
-						done = 1
+					w.WriteMsg(res)
-						break
+					done = 1
-					}
+					break
-				} else {
-					logger.Error("%s", err)
 				}
 			}
 		}
 
 		if done != 1 {
 			res, err = DefaultServer.query(r)
-			logger.Debug("%s query %s %s %s, use default server %s:%s\n",
+			if err != nil {
+				logger.Error("%s", err)
+				continue
+			}
+
+			logger.Debug("%s query %s %s %s, use default server %s:%s, %s\n",
 				w.RemoteAddr(),
 				domain,
 				dns.ClassToString[r.Question[0].Qclass],
 				dns.TypeToString[r.Question[0].Qtype],
-				DefaultServer.Proto, DefaultServer.Addr)
+				DefaultServer.Proto, DefaultServer.Addr,
-			if err == nil {
+				dns.RcodeToString[res.Rcode],
-				if !in_blacklist(res) && res.Rcode != dns.RcodeServerFailure {
+			)
-					w.WriteMsg(res)
+
-					done = 1
+			if res.Rcode != dns.RcodeServerFailure && !in_blacklist(res) {
-				}
+				w.WriteMsg(res)
-			} else {
+				done = 1
-				logger.Error("%s", err)
 			}
 		}