From: Christopher Faulet <cfaulet@haproxy.com>
Date: Tue, 10 Feb 2026 14:24:54 +0000 (+0100)
Subject: MINOR: h1-htx: Disable 0-copy for buffers of different size
X-Git-Tag: v3.4-dev5~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc586b4138d5219875a40b0107ee57120c76bef9;p=thirdparty%2Fhaproxy.git

MINOR: h1-htx: Disable 0-copy for buffers of different size

When a message payload is parsed, it is possible to swap buffers. We must
only take care both buffers have same size. It will be mandatory when the
large buffers support on channels will be added.
---

diff --git a/src/h1_htx.c b/src/h1_htx.c
index 1f806a76e..b956747c2 100644
--- a/src/h1_htx.c
+++ b/src/h1_htx.c
@@ -464,9 +464,10 @@ static size_t h1_copy_msg_data(struct htx **dsthtx, struct buffer *srcbuf, size_
 	 *   - count == srcbuf->data
 	 *   - srcbuf->head == sizeof(struct htx)
 	 *   => we can swap the buffers and place an htx header into
-	 *      the target buffer instead
+	 *      the target buffer instead (for buffers of same size)
 	 */
-	if (unlikely(htx_is_empty(tmp_htx) && count == b_data(srcbuf) &&
+	if (unlikely(b_size(srcbuf) == b_size(htxbuf) &&
+		     htx_is_empty(tmp_htx) && count == b_data(srcbuf) &&
 		     !ofs && b_head_ofs(srcbuf) == sizeof(struct htx))) {
 		void *raw_area = srcbuf->area;
 		void *htx_area = htxbuf->area;