xref: /freebsd/lib/libc/secure/strcat_chk.c (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 /*-
2  *
3  * SPDX-License-Identifier: BSD-2-Clause
4  *
5  * Copyright (c) 2006 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Christos Zoulas.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: strcat_chk.c,v 1.5 2014/09/17 00:39:28 joerg Exp $");
34 
35 #include <string.h>
36 
37 #include <ssp/string.h>
38 
39 char *
40 __strcat_chk(char * __restrict dst, const char * __restrict src, size_t slen)
41 {
42 	char *d;
43 
44 	for (d = dst; *d; d++) {
45 		if (slen-- == 0)
46 			__chk_fail();
47 	}
48 
49 	while (*src) {
50 		if (slen-- == 0)
51 			__chk_fail();
52 		*d++ = *src++;
53 	}
54 
55 	if (slen-- == 0)
56 		__chk_fail();
57 
58 	*d = '\0';
59 	return (dst);
60 }
61