Fix netenv resolver interaction

Also fix endless loop in tcp resolver when network is down

nameserver/nameserver.go

@@ -106,12 +106,6 @@ func handleRequestAsWorker(w dns.ResponseWriter, query *dns.Msg) {
 }
 
 func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) error { //nolint:gocognit // TODO
-	// return with server failure if offline
-	if netenv.GetOnlineStatus() == netenv.StatusOffline {
-		returnServerFailure(w, query)
-		return nil
-	}
-
 	// only process first question, that's how everyone does it.
 	question := query.Question[0]
 	q := &resolver.Query{
@@ -119,6 +113,14 @@ func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) er
 		QType: dns.Type(question.Qtype),
 	}
 
+	// return with server failure if offline
+	if netenv.GetOnlineStatus() == netenv.StatusOffline &&
+		!netenv.IsOnlineStatusTestDomain(q.FQDN) {
+		log.Tracer(ctx).Debugf("resolver: not resolving %s, device is offline", q.FQDN)
+		returnServerFailure(w, query)
+		return nil
+	}
+
 	// check class
 	if question.Qclass != dns.ClassINET {
 		// we only serve IN records, return nxdomain