freebsd-src/lib/libc/secure/strlcat_chk.c
Kyle Evans cf8e5289a1 include: ssp: round out fortification of current set of headers
ssp/ssp.h needed some improvements:
 - `len` isn't always a size_t, it may need casted
 - In some cases we may want to use a len that isn't specified as a
    parameter (e.g., L_ctermid), so __ssp_redirect() should be more
    flexible.
 - In other cases we may want additional checking, so pull all of the
    declaration bits out of __ssp_redirect_raw() so that some functions
    can implement the body themselves.

strlcat/strlcpy should be the last of the fortified functions that get
their own __*_chk symbols, and these cases are only done to be
consistent with the rest of the str*() set.

Reviewed by:	markj
Sponsored by:	Klara, Inc.
Sponsored by:	Stormshield
Differential Revision:	https://reviews.freebsd.org/D45679
2024-07-13 00:16:24 -05:00

71 lines
1.9 KiB
C

/* $OpenBSD: strlcat.c,v 1.15 2015/03/02 21:41:08 millert Exp $ */
/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdio.h>
#include <string.h>
#include <ssp/string.h>
/*
* Appends src to string dst of size dsize (unlike strncat, dsize is the
* full size of dst, not space left). At most dsize-1 characters
* will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
* Returns strlen(src) + MIN(dsize, strlen(initial dst)).
* If retval >= dsize, truncation occurred.
*/
size_t
__strlcat_chk(char * __restrict dst, const char * __restrict src, size_t dsize,
size_t dbufsize)
{
const char *odst = dst;
const char *osrc = src;
size_t n = dsize;
size_t dlen;
if (dsize > dbufsize)
__chk_fail();
/* Find the end of dst and adjust bytes left but don't go past end. */
while (n-- != 0 && *dst != '\0') {
dst++;
}
dlen = dst - odst;
n = dsize - dlen;
if (n-- == 0)
return (dlen + strlen(src));
while (*src != '\0') {
if (n != 0) {
if (dbufsize-- == 0)
__chk_fail();
*dst++ = *src;
n--;
}
src++;
}
if (dbufsize-- == 0)
__chk_fail();
*dst = '\0';
return (dlen + (src - osrc)); /* count does not include NUL */
}