freebsd-skq/lib/libc/string/wcslcat.c
brooks e7eafcf596 Avoid reading pass the end of the source buffer when it is not NUL
terminated.

If this buffer is adjacent to an unmapped page or a version of C with
bounds checked is used this may result in a crash.

PR:		206178
Submitted by:	Alexander Cherepanov <cherepan@mccme.ru>
MFC after:	1 week
2016-01-13 21:50:08 +00:00

75 lines
2.5 KiB
C

/*
* Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* 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.
*
* from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp
*/
#include <sys/cdefs.h>
#if 0
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: wcslcat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
#endif /* LIBC_SCCS and not lint */
#endif
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <wchar.h>
/*
* Appends src to string dst of size siz (unlike wcsncat, siz is the
* full size of dst, not space left). At most siz-1 characters
* will be copied. Always NUL terminates (unless siz == 0).
* Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
* truncation occurred.
*/
size_t
wcslcat(wchar_t *dst, const wchar_t *src, size_t siz)
{
wchar_t *d = dst;
const wchar_t *s = src;
size_t n = siz;
size_t dlen;
/* Find the end of dst and adjust bytes left but don't go past end */
while (n-- != 0 && *d != '\0')
d++;
dlen = d - dst;
n = siz - dlen;
if (n == 0)
return(dlen + wcslen(s));
while (*s != '\0') {
if (n != 1) {
*d++ = *s;
n--;
}
s++;
}
*d = '\0';
return(dlen + (s - src)); /* count does not include NUL */
}