xref: /freebsd/lib/libc/secure/sprintf_chk.c (revision be04fec42638f30f50b5b55fd8e3634c0fb89928)
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: sprintf_chk.c,v 1.6 2009/02/05 05:40:36 lukem Exp $");
34 
35 #include <limits.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 
39 #include <ssp/stdio.h>
40 #undef vsnprintf
41 #undef vsprintf
42 
43 int
__sprintf_chk(char * __restrict buf,int flags,size_t slen,const char * __restrict fmt,...)44 __sprintf_chk(char * __restrict buf, int flags, size_t slen,
45     const char * __restrict fmt, ...)
46 {
47 	va_list ap;
48 	int rv;
49 
50 	va_start(ap, fmt);
51 	if (slen > (size_t)INT_MAX)
52 		rv = vsprintf(buf, fmt, ap);
53 	else {
54 		if ((rv = vsnprintf(buf, slen, fmt, ap)) >= 0 &&
55 		    (size_t)rv >= slen)
56 			__chk_fail();
57 	}
58 	va_end(ap);
59 
60 	return (rv);
61 }
62