1/* $NetBSD: gets_chk.c,v 1.6 2010/01/17 23:13:32 wiz 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: gets_chk.c,v 1.6 2010/01/17 23:13:32 wiz Exp $"); 33 34/*LINTLIBRARY*/ 35 36#include <ssp/ssp.h> 37#include <stdio.h> 38#include <string.h> 39#include <limits.h> 40#include <stdlib.h> 41#include <ssp/stdio.h> 42 43extern char *__gets(char *); 44#undef gets 45 46char * 47__gets_chk(char * __restrict buf, size_t slen) 48{ 49 char *abuf; 50 size_t len; 51 52 if (slen >= (size_t)INT_MAX) 53 return __gets(buf); 54 55 if ((abuf = malloc(slen + 1)) == NULL) 56 return __gets(buf); 57 58 if (fgets(abuf, (int)(slen + 1), stdin) == NULL) { 59 free(abuf); 60 return NULL; 61 } 62 63 len = strlen(abuf); 64 if (len > 0 && abuf[len - 1] == '\n') 65 --len; 66 67 if (len >= slen) 68 __chk_fail(); 69 70 (void)memcpy(buf, abuf, len); 71 72 buf[len] = '\0'; 73 free(abuf); 74 return buf; 75} 76