freebsd-src/lib/libc/secure/strncat_chk.c
Kyle Evans be04fec426 Import _FORTIFY_SOURCE implementation from NetBSD
This is a mostly-unmodified copy of the various *_chk implementations
and headers from NetBSD, without yet modifying system headers to start
actually including them.  A future commit will also apply the needed
bits to fix ssp/unistd.h.

Reviewed by:	imp, pauamma_gundo.com (both previous versions), kib
Sponsored by:	Stormshield
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D32306
2024-05-13 00:23:49 -05:00

71 lines
2.1 KiB
C

/*-
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: strncat_chk.c,v 1.5 2014/09/17 00:39:28 joerg Exp $");
#include <stdio.h>
#include <string.h>
#include <ssp/string.h>
char *
__strncat_chk(char * __restrict dst, const char * __restrict src, size_t len,
size_t slen)
{
char *d;
if (len == 0)
return (dst);
if (len > slen)
__chk_fail();
for (d = dst; *d; d++) {
if (slen-- == 0)
__chk_fail();
}
do {
if ((*d = *src++) == '\0')
break;
if (slen-- == 0)
__chk_fail();
d++;
} while (--len != 0);
if (slen-- == 0)
__chk_fail();
*d = '\0';
return (dst);
}