Make sure we find a link-local address and rdomain

pointed out by jsg & miod

diff --git a/sbin/dhcp6leased/dhcp6leased.c b/sbin/dhcp6leased/dhcp6leased.c
index 658be71..9d9c4d5 100644 (file)
--- a/sbin/dhcp6leased/dhcp6leased.c
+++ b/sbin/dhcp6leased/dhcp6leased.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dhcp6leased.c,v 1.4 2024/06/02 15:43:24 florian Exp $ */
+/*     $OpenBSD: dhcp6leased.c,v 1.5 2024/06/02 17:33:48 florian Exp $ */
 
 /*
  * Copyright (c) 2017, 2021, 2024 Florian Obser <florian@openbsd.org>
@@ -750,8 +750,8 @@ void
 open_udpsock(uint32_t if_index)
 {
        struct ifaddrs          *ifap, *ifa;
-       struct sockaddr_in6     *sin6;
-       int                      udpsock = -1, rdomain, opt = 1;
+       struct sockaddr_in6     *sin6 = NULL;
+       int                      udpsock = -1, rdomain = -1, opt = 1;
        char                     if_name[IF_NAMESIZE];
 
        if (if_indextoname(if_index, if_name) == NULL) {
@@ -797,6 +797,18 @@ open_udpsock(uint32_t if_index)
                        }
        }
 
+       if(sin6 == NULL) {
+               log_warnx("%s: missing link-local address on %s", __func__,
+                   if_name);
+               goto out;
+       }
+
+       if(rdomain == -1) {
+               log_warnx("%s: cannot find rdomain for %s", __func__,
+                   if_name);
+               goto out;
+       }
+
        sin6->sin6_port = htons(CLIENT_PORT);
        log_debug("%s: %s rdomain: %d", __func__, sin6_to_str(sin6),
            rdomain);