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