suppress the warning of openwrt

zfl9 · zfl9 · commit 3918af1cce81 · 2019-10-20T12:09:45.000+08:00
diff --git a/netutils.c b/netutils.c
@@ -33,6 +33,9 @@
 #define KEEPALIVE_RETRY_MAX_COUNT 5
 #define KEEPALIVE_RETRY_INTERVAL_SEC 1
 
+/* suppress the warning of openwrt */
+int initgroups(const char *user, gid_t group);
+
 /* setsockopt(SO_KEEPALIVE) */
 void set_keepalive(int sockfd) {
     if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &(int){1}, sizeof(int))) {
