1 /* $NetBSD: strncat_chk.c,v 1.4 2009/11/17 20:44:26 drochner Exp $ */ 2 3 /*- 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include <sys/cdefs.h> 32 __RCSID("$NetBSD: strncat_chk.c,v 1.4 2009/11/17 20:44:26 drochner Exp $"); 33 34 /*LINTLIBRARY*/ 35 36 #include <ssp/ssp.h> 37 #include <string.h> 38 #include <stdio.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