1/*	$NetBSD: gets_chk.c,v 1.5 2008/04/28 20:23:00 martin 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: gets_chk.c,v 1.5 2008/04/28 20:23:00 martin 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 gets
44
45char *
46__gets_chk(char * __restrict buf, size_t slen)
47{
48	char *abuf;
49	size_t len;
50
51	if (slen >= (size_t)INT_MAX)
52		return gets(buf);
53
54	if ((abuf = malloc(slen + 1)) == NULL)
55		return gets(buf);
56
57	if (fgets(abuf, (int)(slen + 1), stdin) == NULL) {
58		free(abuf);
59		return NULL;
60	}
61
62	len = strlen(abuf);
63	if (len > 0 && abuf[len - 1] == '\n')
64		--len;
65
66	if (len >= slen)
67		__chk_fail();
68
69	(void)memcpy(buf, abuf, len);
70
71	buf[len] = '\0';
72	free(abuf);
73	return buf;
74}
75