1 /* $NetBSD: strncat_chk.c,v 1.5 2014/09/17 00:39:28 joerg Exp $ */
2
3 /*-
4 * Copyright (c) 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: strncat_chk.c,v 1.5 2014/09/17 00:39:28 joerg Exp $");
33
34 /*LINTLIBRARY*/
35
36 #include <ssp/ssp.h>
37 #include <string.h>
38 #include <stdio.h>
39
40 char *__strncat_chk(char * __restrict, const char * __restrict, size_t,
41 size_t);
42
43 char *
__strncat_chk(char * __restrict dst,const char * __restrict src,size_t len,size_t slen)44 __strncat_chk(char * __restrict dst, const char * __restrict src, size_t len,
45 size_t slen)
46 {
47 char *d;
48
49 if (len == 0)
50 return dst;
51
52 if (len > slen)
53 __chk_fail();
54
55 for (d = dst; *d; d++) {
56 if (slen-- == 0)
57 __chk_fail();
58 }
59
60 do {
61 if ((*d = *src++) == '\0')
62 break;
63 if (slen-- == 0)
64 __chk_fail();
65 d++;
66 } while (--len != 0);
67
68 if (slen-- == 0)
69 __chk_fail();
70
71 *d = '\0';
72 return dst;
73 }
74
