Replace the one use of ibuf_prepend() using a similar ibuf_new() + ibuf_cat()

method but instead of overwriting ibuf internals replace the buf a level up.
Users of ikev2_msg_send() are not allowed to hold and reuse a pointer to
msg_data (which is another footgun to disarm at some point).
OK tb@

diff --git a/sbin/iked/iked.h b/sbin/iked/iked.h
index 059c1fe..2a26b93 100644 (file)
--- a/sbin/iked/iked.h
+++ b/sbin/iked/iked.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: iked.h,v 1.213 2023/05/23 13:57:14 claudio Exp $      */
+/*     $OpenBSD: iked.h,v 1.214 2023/05/30 08:41:15 claudio Exp $      */
 
 /*
  * Copyright (c) 2019 Tobias Heider <tobias.heider@stusta.de>
@@ -1279,7 +1279,6 @@ struct ibuf *
         ibuf_dup(struct ibuf *);
 struct ibuf *
         ibuf_random(size_t);
-int     ibuf_prepend(struct ibuf *, void *, size_t);
 int     ibuf_strcat(struct ibuf **, const char *);
 int     ibuf_strlen(struct ibuf *);
 

diff --git a/sbin/iked/ikev2_msg.c b/sbin/iked/ikev2_msg.c
index a3fe326..77a9a16 100644 (file)
--- a/sbin/iked/ikev2_msg.c
+++ b/sbin/iked/ikev2_msg.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ikev2_msg.c,v 1.92 2023/05/23 13:57:14 claudio Exp $  */
+/*     $OpenBSD: ikev2_msg.c,v 1.93 2023/05/30 08:41:15 claudio Exp $  */
 
 /*
  * Copyright (c) 2019 Tobias Heider <tobias.heider@stusta.de>
@@ -290,10 +290,18 @@ ikev2_msg_send(struct iked *env, struct iked_message *msg)
            ibuf_length(buf), isnatt ? ", NAT-T" : "");
 
        if (isnatt) {
-               if (ibuf_prepend(buf, &natt, sizeof(natt)) == -1) {
+               struct ibuf *new;
+               if ((new = ibuf_new(&natt, sizeof(natt))) == NULL) {
                        log_debug("%s: failed to set NAT-T", __func__);
                        return (-1);
                }
+               if (ibuf_cat(new, buf) == -1) {
+                       ibuf_free(new);
+                       log_debug("%s: failed to set NAT-T", __func__);
+                       return (-1);
+               }
+               ibuf_free(buf);
+               buf = msg->msg_data = new;
        }
 
        if (sendtofrom(msg->msg_fd, ibuf_data(buf), ibuf_size(buf), 0,

diff --git a/sbin/iked/imsg_util.c b/sbin/iked/imsg_util.c
index 6774e2e..67ba8a2 100644 (file)
--- a/sbin/iked/imsg_util.c
+++ b/sbin/iked/imsg_util.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: imsg_util.c,v 1.16 2023/05/23 13:57:14 claudio Exp $  */
+/*     $OpenBSD: imsg_util.c,v 1.17 2023/05/30 08:41:15 claudio Exp $  */
 
 /*
  * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
@@ -145,25 +145,6 @@ ibuf_setsize(struct ibuf *buf, size_t len)
        return (0);
 }
 
-int
-ibuf_prepend(struct ibuf *buf, void *data, size_t len)
-{
-       struct ibuf     *new;
-
-       /* Swap buffers (we could also use memmove here) */
-       if ((new = ibuf_new(data, len)) == NULL)
-               return (-1);
-       if (ibuf_cat(new, buf) == -1) {
-               ibuf_free(new);
-               return (-1);
-       }
-       free(buf->buf);
-       memcpy(buf, new, sizeof(*buf));
-       free(new);
-
-       return (0);
-}
-
 int
 ibuf_strcat(struct ibuf **buf, const char *s)
 {