Do not send zero sized vendor or client ids.

The frontend and engine do not like this due to improved error
checking.

Found by Josh Grosse and Renato Aguiar, thanks!

diff --git a/sbin/dhcpleased/dhcpleased.c b/sbin/dhcpleased/dhcpleased.c
index 0a6a7e5..d3ff1ce 100644 (file)
--- a/sbin/dhcpleased/dhcpleased.c
+++ b/sbin/dhcpleased/dhcpleased.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dhcpleased.c,v 1.31 2024/08/25 09:53:53 florian Exp $ */
+/*     $OpenBSD: dhcpleased.c,v 1.32 2024/08/27 05:55:39 florian Exp $ */
 
 /*
  * Copyright (c) 2017, 2021 Florian Obser <florian@openbsd.org>
@@ -733,14 +733,18 @@ main_imsg_send_config(struct dhcpleased_conf *xconf)
                    sizeof(*iface_conf));
                main_imsg_compose_engine(IMSG_RECONF_IFACE, -1, iface_conf,
                    sizeof(*iface_conf));
-               main_imsg_compose_frontend(IMSG_RECONF_VC_ID, -1,
-                   iface_conf->vc_id, iface_conf->vc_id_len);
-               main_imsg_compose_engine(IMSG_RECONF_VC_ID, -1,
-                   iface_conf->vc_id, iface_conf->vc_id_len);
-               main_imsg_compose_frontend(IMSG_RECONF_C_ID, -1,
-                   iface_conf->c_id, iface_conf->c_id_len);
-               main_imsg_compose_engine(IMSG_RECONF_C_ID, -1,
-                   iface_conf->c_id, iface_conf->c_id_len);
+               if (iface_conf->vc_id_len) {
+                       main_imsg_compose_frontend(IMSG_RECONF_VC_ID, -1,
+                           iface_conf->vc_id, iface_conf->vc_id_len);
+                       main_imsg_compose_engine(IMSG_RECONF_VC_ID, -1,
+                           iface_conf->vc_id, iface_conf->vc_id_len);
+               }
+               if (iface_conf->c_id_len) {
+                       main_imsg_compose_frontend(IMSG_RECONF_C_ID, -1,
+                           iface_conf->c_id, iface_conf->c_id_len);
+                       main_imsg_compose_engine(IMSG_RECONF_C_ID, -1,
+                           iface_conf->c_id, iface_conf->c_id_len);
+               }
                if (iface_conf->h_name != NULL)
                        main_imsg_compose_frontend(IMSG_RECONF_H_NAME, -1,
                            iface_conf->h_name, strlen(iface_conf->h_name) + 1);