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freebsd/lib/libc/stdio/vswprintf.c
David Schultz 666d00d34a If the size passed to {,v}s{w,n}printf is larger than INT_MAX+1
(i.e., the return value would overflow), set errno to EOVERFLOW
and return an error.  This improves the chances that buggy
applications -- for instance, ones that pass in a negative integer
as the size due to a bogus calculation -- will fail in safe ways.
Returning an error in these situations is specified by POSIX, but
POSIX appears to have an off-by-one error that isn't duplicated in
this change.

Previously, some of these functions would silently cap the size at
INT_MAX+1, and others would exit with an error after writing more
than INT_MAX characters.

PR:		39256
MFC after:	2 weeks
2012-04-21 06:10:18 +00:00

115 lines
3.3 KiB
C

/* $OpenBSD: vasprintf.c,v 1.4 1998/06/21 22:13:47 millert Exp $ */
/*
* Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* Copyright (c) 2011 The FreeBSD Foundation
* All rights reserved.
* Portions of this software were developed by David Chisnall
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if 0
__FBSDID("FreeBSD: src/lib/libc/stdio/vasprintf.c,v 1.16 2002/08/21 16:19:57 mike Exp ");
#endif
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include "local.h"
#include "xlocale_private.h"
int
vswprintf_l(wchar_t * __restrict s, size_t n, locale_t locale,
const wchar_t * __restrict fmt, __va_list ap)
{
static const mbstate_t initial;
mbstate_t mbs;
FILE f = FAKE_FILE;
char *mbp;
int ret, sverrno;
size_t nwc;
FIX_LOCALE(locale);
if (n == 0) {
errno = EINVAL;
return (-1);
}
if (n - 1 > INT_MAX) {
errno = EOVERFLOW;
*s = L'\0';
return (-1);
}
f._flags = __SWR | __SSTR | __SALC;
f._bf._base = f._p = (unsigned char *)malloc(128);
if (f._bf._base == NULL) {
errno = ENOMEM;
*s = L'\0';
return (-1);
}
f._bf._size = f._w = 127; /* Leave room for the NUL */
ret = __vfwprintf(&f, locale, fmt, ap);
if (ret < 0) {
sverrno = errno;
free(f._bf._base);
errno = sverrno;
*s = L'\0';
return (-1);
}
*f._p = '\0';
mbp = f._bf._base;
/*
* XXX Undo the conversion from wide characters to multibyte that
* fputwc() did in __vfwprintf().
*/
mbs = initial;
nwc = mbsrtowcs_l(s, (const char **)&mbp, n, &mbs, locale);
free(f._bf._base);
if (nwc == (size_t)-1) {
errno = EILSEQ;
*s = L'\0';
return (-1);
}
if (nwc == n) {
s[n - 1] = L'\0';
errno = EOVERFLOW;
return (-1);
}
return (ret);
}
int
vswprintf(wchar_t * __restrict s, size_t n, const wchar_t * __restrict fmt,
__va_list ap)
{
return vswprintf_l(s, n, __get_locale(), fmt, ap);
}