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 * $FreeBSD: head/lib/libc/stdio/gets_s.c 333895 2018-05-19 21:26:07Z cy $
37 */
38
39 #include "namespace.h"
40 #include <errno.h>
41 #include <unistd.h>
42 #include <stdint.h>
43 #include <stdio.h>
44 #include "un-namespace.h"
45 #include "libc_private.h"
46 #include "local.h"
47
48 static inline char *
_gets_s(char * buf,rsize_t n)49 _gets_s(char *buf, rsize_t n)
50 {
51 int c;
52 char *s;
53
54 ORIENT(stdin, -1);
55 for (s = buf, n--; (c = __sgetc(stdin)) != '\n' && n > 0 ; n--) {
56 if (c == EOF) {
57 if (s == buf) {
58 return (NULL);
59 } else
60 break;
61 } else
62 *s++ = c;
63 }
64
65 /*
66 * If end of buffer reached, discard until \n or eof.
67 * Then throw an error.
68 */
69 if (n == 0) {
70 /* discard */
71 while ((c = __sgetc(stdin)) != '\n' && c != EOF);
72 /* throw the error after lock released prior to exit */
73 __throw_constraint_handler_s("gets_s : end of buffer", E2BIG);
74 return (NULL);
75 }
76 *s = 0;
77 return (buf);
78 }
79
80 /* ISO/IEC 9899:2011 K.3.7.4.1 */
81 char *
gets_s(char * buf,rsize_t n)82 gets_s(char *buf, rsize_t n)
83 {
84 char *ret;
85 if (buf == NULL) {
86 __throw_constraint_handler_s("gets_s : str is NULL", EINVAL);
87 return(NULL);
88 } else if (n > RSIZE_MAX) {
89 __throw_constraint_handler_s("gets_s : n > RSIZE_MAX",
90 EINVAL);
91 return(NULL);
92 } else if (n == 0) {
93 __throw_constraint_handler_s("gets_s : n == 0", EINVAL);
94 return(NULL);
95 }
96
97 #if 0 /* XXX */
98 FLOCKFILE_CANCELSAFE(stdin);
99 #else
100 FLOCKFILE(stdin);
101 #endif
102 ret = _gets_s(buf, n);
103 #if 0 /* XXX */
104 FUNLOCKFILE_CANCELSAFE();
105 #else
106 FUNLOCKFILE(stdin);
107 #endif
108 return (ret);
109 }
110