minix/lib/nbsd_libc/ssp/strncat_chk.c

/*	$NetBSD: strncat_chk.c,v 1.4 2009/11/17 20:44:26 drochner Exp $	*/

/*-
 * Copyright (c) 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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>
__RCSID("$NetBSD: strncat_chk.c,v 1.4 2009/11/17 20:44:26 drochner Exp $");

/*LINTLIBRARY*/

#include <ssp/ssp.h>
#include <string.h>
#include <stdio.h>

#if __SSP_FORTIFY_LEVEL > 0

char *
__strncat_chk(char * __restrict dst, const char * __restrict src, size_t len,
    size_t slen)
{
	char *d;

	if (len == 0)
		return dst;

	if (len > slen)
		__chk_fail();

	for (d = dst; *d; d++) {
		if (slen-- == 0)
			__chk_fail();
	}

	do {
		if ((*d = *src++) == '\0')
			break;
		if (slen-- == 0)
			__chk_fail();
		d++;
	} while (--len != 0);

	if (slen-- == 0)
		__chk_fail();

	*d = '\0';
	return dst;
}

#endif