xref: /netbsd-src/lib/libc/stdio/vsnprintf.c (revision 76c7fc5f6b13ed0b1508e6b313e88e59977ed78e)
1 /*	$NetBSD: vsnprintf.c,v 1.29 2017/01/12 18:16:52 christos Exp $	*/
2 
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  * 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  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)vsnprintf.c	8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: vsnprintf.c,v 1.29 2017/01/12 18:16:52 christos Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include "namespace.h"
45 
46 #include <assert.h>
47 #include <errno.h>
48 #include <locale.h>
49 #include <stdio.h>
50 #include "reentrant.h"
51 #include "setlocale_local.h"
52 #include "local.h"
53 
54 #if __SSP_FORTIFY_LEVEL != 0
55 # undef vsnprintf
56 # define vsnprintf _vsnprintf
57 # undef snprintf
58 # define snprintf _snprintf
59 int      snprintf(char * __restrict, size_t, const char * __restrict, ...)
60     __printflike(3, 4);
61 int      vsnprintf(char * __restrict, size_t, const char * __restrict,
62     __va_list) __printflike(3, 0);
63 #endif
64 
65 #ifdef __weak_alias
66 __weak_alias(vsnprintf,_vsnprintf)
67 __weak_alias(vsnprintf_l,_vsnprintf_l)
68 __weak_alias(snprintf,_snprintf)
69 __weak_alias(snprintf_l,_snprintf_l)
70 #endif
71 
72 int
73 vsnprintf_l(char *str, size_t n, locale_t loc, const char *fmt, va_list ap)
74 {
75 	int ret;
76 	FILE f;
77 	struct __sfileext fext;
78 	unsigned char dummy[1];
79 
80 	_DIAGASSERT(n == 0 || str != NULL);
81 	_DIAGASSERT(fmt != NULL);
82 
83 	if (n > INT_MAX) {
84 		errno = EOVERFLOW;
85 		return -1;
86 	}
87 
88 	_FILEEXT_SETUP(&f, &fext);
89 	f._file = -1;
90 	f._flags = __SWR | __SSTR;
91 	if (n == 0) {
92 		f._bf._base = f._p = dummy;
93 		f._bf._size = f._w = 0;
94 	} else {
95 		f._bf._base = f._p = (unsigned char *)str;
96 		_DIAGASSERT(__type_fit(int, n - 1));
97 		f._bf._size = f._w = (int)(n - 1);
98 	}
99 	ret = __vfprintf_unlocked_l(&f, loc, fmt, ap);
100 	*f._p = 0;
101 	return ret;
102 }
103 
104 int
105 vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
106 {
107 	return vsnprintf_l(str, n, _current_locale(), fmt, ap);
108 }
109 
110 int
111 snprintf(char *str, size_t n, const char *fmt, ...)
112 {
113 	va_list ap;
114 	int ret;
115 
116 	va_start(ap, fmt);
117 	ret = vsnprintf(str, n, fmt, ap);
118 	va_end(ap);
119 	return ret;
120 }
121 
122 int
123 snprintf_l(char *str, size_t n, locale_t loc, const char *fmt, ...)
124 {
125 	va_list ap;
126 	int ret;
127 
128 	va_start(ap, fmt);
129 	ret = vsnprintf_l(str, n, loc, fmt, ap);
130 	va_end(ap);
131 	return ret;
132 }
133