dnsproxy: Check split routing when creating a server

If VPN is not the default service i.e., default route is not via
VPN service then we need to add the VPN specified DNS server to
the proxy because some of the DNS queries might be to the VPN domain.

Reported-by: Yevhen Kyriukha <kirgene@gmail.com>

src/connman.h

@@ -738,6 +738,7 @@ void __connman_service_set_pac(struct connman_service *service,
 					const char *pac);
 bool __connman_service_is_hidden(struct connman_service *service);
 bool __connman_service_is_split_routing(struct connman_service *service);
+bool __connman_service_index_is_split_routing(int index);
 int __connman_service_get_index(struct connman_service *service);
 void __connman_service_set_hidden(struct connman_service *service);
 void __connman_service_set_hostname(struct connman_service *service,

src/dnsproxy.c

@@ -2282,7 +2282,9 @@ static struct server_data *create_server(int index,
 	}
 
 	if (protocol == IPPROTO_UDP) {
-		if (__connman_service_index_is_default(data->index)) {
+		if (__connman_service_index_is_default(data->index) ||
+				__connman_service_index_is_split_routing(
+								data->index)) {
 			data->enabled = true;
 			DBG("Adding DNS server %s", data->server);
 		}

src/service.c

@@ -2393,6 +2393,20 @@ __connman_service_is_split_routing(struct connman_service *service)
 	return service->do_split_routing;
 }
 
+bool __connman_service_index_is_split_routing(int index)
+{
+	struct connman_service *service;
+
+	if (index < 0)
+		return false;
+
+	service = __connman_service_lookup_from_index(index);
+	if (!service)
+		return false;
+
+	return __connman_service_is_split_routing(service);
+}
+
 int __connman_service_get_index(struct connman_service *service)
 {
 	if (!service)