openwrt/package/utils/busybox/patches/230-ntpd_delayed_resolve.patch

--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -251,6 +251,7 @@ typedef struct {
 typedef struct {
 	len_and_sockaddr *p_lsa;
 	char             *p_dotted;
+	char             *p_hostname;
 	int              p_fd;
 	int              datapoint_idx;
 	uint32_t         lastpkt_refid;
@@ -756,8 +757,9 @@ add_peers(const char *s)
 	peer_t *p;
 
 	p = xzalloc(sizeof(*p));
-	p->p_lsa = xhost2sockaddr(s, 123);
-	p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa);
+	p->p_hostname = s;
+	p->p_lsa = NULL;
+	p->p_dotted = NULL;
 	p->p_fd = -1;
 	p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3);
 	p->next_action_time = G.cur_time; /* = set_next(p, 0); */
@@ -806,6 +808,25 @@ send_query_to_peer(peer_t *p)
 	 *
 	 * Uncomment this and use strace to see it in action:
 	 */
+
+	/* See if the peer hostname already resolved yet, if not, retry to resolv and return on failure */
+	if (!p->p_lsa)
+	{
+		p->p_lsa = host2sockaddr(p->p_hostname, 123);
+
+		if (p->p_lsa)
+		{
+			p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa);
+			VERB1 bb_error_msg("resolved peer %s to %s", p->p_hostname, p->p_dotted);
+		}
+		else
+		{
+			set_next(p, RETRY_INTERVAL);
+			VERB1 bb_error_msg("could not resolve peer %s, skipping", p->p_hostname);
+			return;
+		}
+	}
+
 #define PROBE_LOCAL_ADDR /* { len_and_sockaddr lsa; lsa.len = LSA_SIZEOF_SA; getsockname(p->query.fd, &lsa.u.sa, &lsa.len); } */
 
 	if (p->p_fd == -1) {