xref: /netbsd/lib/libc/ssp/fgets_chk.c (revision 6550d01e)
1 /*	$NetBSD: fgets_chk.c,v 1.6 2009/02/05 05:41:51 lukem 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: fgets_chk.c,v 1.6 2009/02/05 05:41:51 lukem Exp $");
33 
34 /*LINTLIBRARY*/
35 
36 #include <ssp/ssp.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <limits.h>
40 #include <stdlib.h>
41 #include <ssp/stdio.h>
42 
43 #undef fgets
44 
45 char *
46 __fgets_chk(char * __restrict buf, int len, size_t slen, FILE *fp)
47 {
48 	if (slen >= (size_t)INT_MAX)
49 		return fgets(buf, len, fp);
50 
51 	if (len >= 0 && (size_t)len > slen)
52 		__chk_fail();
53 
54 	return fgets(buf, len, fp);
55 }
56