1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 2017, 2018
7 * Cyril S. E. Schubert
8 *
9 * This code is derived from software contributed to Berkeley by
10 * Chris Torek.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39
40 #include "namespace.h"
41 #include <errno.h>
42 #include <unistd.h>
43 #include <stdint.h>
44 #include <stdio.h>
45 #include "un-namespace.h"
46 #include "libc_private.h"
47 #include "local.h"
48
49 static inline char *
_gets_s(char * buf,rsize_t n)50 _gets_s(char *buf, rsize_t n)
51 {
52 int c;
53 char *s;
54
55 ORIENT(stdin, -1);
56 for (s = buf, n--; (c = __sgetc(stdin)) != '\n' && n > 0 ; n--) {
57 if (c == EOF) {
58 if (s == buf) {
59 return (NULL);
60 } else
61 break;
62 } else
63 *s++ = c;
64 }
65
66 /*
67 * If end of buffer reached, discard until \n or eof.
68 * Then throw an error.
69 */
70 if (n == 0) {
71 /* discard */
72 while ((c = __sgetc(stdin)) != '\n' && c != EOF);
73 /* throw the error after lock released prior to exit */
74 __throw_constraint_handler_s("gets_s : end of buffer", E2BIG);
75 return (NULL);
76 }
77 *s = 0;
78 return (buf);
79 }
80
81 /* ISO/IEC 9899:2011 K.3.7.4.1 */
82 char *
gets_s(char * buf,rsize_t n)83 gets_s(char *buf, rsize_t n)
84 {
85 char *ret;
86 if (buf == NULL) {
87 __throw_constraint_handler_s("gets_s : str is NULL", EINVAL);
88 return(NULL);
89 } else if (n > RSIZE_MAX) {
90 __throw_constraint_handler_s("gets_s : n > RSIZE_MAX",
91 EINVAL);
92 return(NULL);
93 } else if (n == 0) {
94 __throw_constraint_handler_s("gets_s : n == 0", EINVAL);
95 return(NULL);
96 }
97
98 FLOCKFILE_CANCELSAFE(stdin);
99 ret = _gets_s(buf, n);
100 FUNLOCKFILE_CANCELSAFE();
101 return (ret);
102 }
103