1 /* $NetBSD: gets_chk.c,v 1.4 2007/08/04 19:37:52 kristerw 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 #include <sys/cdefs.h> 39 __RCSID("$NetBSD: gets_chk.c,v 1.4 2007/08/04 19:37:52 kristerw Exp $"); 40 41 /*LINTLIBRARY*/ 42 43 #include <ssp/ssp.h> 44 #include <stdio.h> 45 #include <string.h> 46 #include <limits.h> 47 #include <stdlib.h> 48 #include <ssp/stdio.h> 49 50 #undef gets 51 52 char * 53 __gets_chk(char * __restrict buf, size_t slen) 54 { 55 char *abuf; 56 size_t len; 57 58 if (slen >= (size_t)INT_MAX) 59 return gets(buf); 60 61 if ((abuf = malloc(slen + 1)) == NULL) 62 return gets(buf); 63 64 if (fgets(abuf, (int)(slen + 1), stdin) == NULL) 65 return NULL; 66 67 len = strlen(abuf); 68 if (len > 0 && abuf[len - 1] == '\n') 69 --len; 70 71 if (len >= slen) 72 __chk_fail(); 73 74 (void)memcpy(buf, abuf, len); 75 76 buf[len] = '\0'; 77 free(abuf); 78 return buf; 79 } 80