Only vis(3) the option, not the rest of the packet.

Lots of head scratching and help from the hackroom ensued because of a
inconveniently placed \r that truncated a string and placed garbage at
a weird place.

diff --git a/sbin/dhcp6leased/engine.c b/sbin/dhcp6leased/engine.c
index 5ab0754..7ae2af6 100644 (file)
--- a/sbin/dhcp6leased/engine.c
+++ b/sbin/dhcp6leased/engine.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: engine.c,v 1.17 2024/07/09 16:24:57 florian Exp $     */
+/*     $OpenBSD: engine.c,v 1.18 2024/07/10 10:30:46 florian Exp $     */
 
 /*
  * Copyright (c) 2017, 2021, 2024 Florian Obser <florian@openbsd.org>
@@ -1009,8 +1009,13 @@ parse_ia_pd_options(uint8_t *p, size_t len, struct prefix *prefix)
                        }
                        memcpy(&status_code, p, sizeof(uint16_t));
                        status_code = ntohs(status_code);
-                       visbuf = calloc(4, len - 2);
-                       strvisx(visbuf, p + 2, len - 2, VIS_SAFE);
+                       /* must be at least 4 * srclen + 1 long */
+                       visbuf = calloc(4, opt_hdr.len - 2 + 1);
+                       if (visbuf == NULL) {
+                               log_warn("%s", __func__);
+                               break;
+                       }
+                       strvisx(visbuf, p + 2, opt_hdr.len - 2, VIS_SAFE);
                        log_debug("%s: %s - %s", __func__,
                            dhcp_status2str(status_code), visbuf);
                        break;