1 /* $NetBSD: gets_chk.c,v 1.7 2013/10/04 20:49:16 christos 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 1.7 2013/10/04 20:49:16 christos 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 extern char *__gets(char *);
44 #undef gets
45 #ifdef __NEWLIB__
46 #define __gets gets
47 #endif
48
49 char *
__gets_chk(char * __restrict buf,size_t slen)50 __gets_chk(char * __restrict buf, size_t slen)
51 {
52 char *abuf;
53 size_t len;
54
55 if (slen >= (size_t)INT_MAX)
56 return __gets(buf);
57
58 if ((abuf = malloc(slen + 1)) == NULL)
59 return __gets(buf);
60
61 if (fgets(abuf, (int)(slen + 1), stdin) == NULL) {
62 free(abuf);
63 return NULL;
64 }
65
66 len = strlen(abuf);
67 if (len > 0 && abuf[len - 1] == '\n')
68 --len;
69
70 if (len >= slen)
71 __chk_fail();
72
73 (void)memcpy(buf, abuf, len);
74
75 buf[len] = '\0';
76 free(abuf);
77 return buf;
78 }
79
