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 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Copyright (c) 2011 The FreeBSD Foundation
11 * All rights reserved.
12 * Portions of this software were developed by David Chisnall
13 * under sponsorship from the FreeBSD Foundation.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 *    notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 *    notice, this list of conditions and the following disclaimer in the
22 *    documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40#if defined(LIBC_SCCS) && !defined(lint)
41static char sccsid[] = "@(#)vsnprintf.c	8.1 (Berkeley) 6/4/93";
42#endif /* LIBC_SCCS and not lint */
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD$");
45
46#include <errno.h>
47#include <limits.h>
48#include <stdio.h>
49#include "local.h"
50#include "xlocale_private.h"
51
52int
53vsnprintf_l(char * __restrict str, size_t n, locale_t locale,
54		const char * __restrict fmt, __va_list ap)
55{
56	size_t on;
57	int ret;
58	char dummy[2];
59	FILE f = FAKE_FILE;
60	FIX_LOCALE(locale);
61
62	on = n;
63	if (n != 0)
64		n--;
65	if (n > INT_MAX) {
66		errno = EOVERFLOW;
67		*str = '\0';
68		return (EOF);
69	}
70	/* Stdio internals do not deal correctly with zero length buffer */
71	if (n == 0) {
72		if (on > 0)
73	  		*str = '\0';
74		str = dummy;
75		n = 1;
76	}
77	f._flags = __SWR | __SSTR;
78	f._bf._base = f._p = (unsigned char *)str;
79	f._bf._size = f._w = n;
80	ret = __vfprintf(&f, locale, fmt, ap);
81	if (on > 0)
82		*f._p = '\0';
83	return (ret);
84}
85int
86vsnprintf(char * __restrict str, size_t n, const char * __restrict fmt,
87    __va_list ap)
88{
89	return vsnprintf_l(str, n, __get_locale(), fmt, ap);
90}
91