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 43 #undef gets 44 45 char * 46 __gets_chk(char * __restrict buf, size_t slen) 47 { 48 char *abuf; 49 size_t len; 50 51 if (slen >= (size_t)INT_MAX) 52 return gets(buf); 53 54 if ((abuf = malloc(slen + 1)) == NULL) 55 return gets(buf); 56 57 if (fgets(abuf, (int)(slen + 1), stdin) == NULL) { 58 free(abuf); 59 return NULL; 60 } 61 62 len = strlen(abuf); 63 if (len > 0 && abuf[len - 1] == '\n') 64 --len; 65 66 if (len >= slen) 67 __chk_fail(); 68 69 (void)memcpy(buf, abuf, len); 70 71 buf[len] = '\0'; 72 free(abuf); 73 return buf; 74 } 75