1 /*- 2 * 3 * SPDX-License-Identifier: BSD-2-Clause 4 * 5 * Copyright (c) 2006 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Christos Zoulas. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 #include <sys/cdefs.h> 33 __RCSID("$NetBSD: strncat_chk.c,v 1.5 2014/09/17 00:39:28 joerg Exp $"); 34 35 #include <stdio.h> 36 #include <string.h> 37 38 #include <ssp/string.h> 39 40 char * 41 __strncat_chk(char * __restrict dst, const char * __restrict src, size_t len, 42 size_t slen) 43 { 44 char *d; 45 46 if (len == 0) 47 return (dst); 48 49 if (len > slen) 50 __chk_fail(); 51 52 for (d = dst; *d; d++) { 53 if (slen-- == 0) 54 __chk_fail(); 55 } 56 57 do { 58 if ((*d = *src++) == '\0') 59 break; 60 if (slen-- == 0) 61 __chk_fail(); 62 d++; 63 } while (--len != 0); 64 65 if (slen-- == 0) 66 __chk_fail(); 67 68 *d = '\0'; 69 return (dst); 70 } 71