1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 2017, 2018 7 * Cyril S. E. Schubert 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Chris Torek. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $FreeBSD: head/lib/libc/stdio/gets_s.c 333895 2018-05-19 21:26:07Z cy $ 37 */ 38 39 #include "namespace.h" 40 #include <errno.h> 41 #include <unistd.h> 42 #include <stdint.h> 43 #include <stdio.h> 44 #include "un-namespace.h" 45 #include "libc_private.h" 46 #include "local.h" 47 48 static inline char * 49 _gets_s(char *buf, rsize_t n) 50 { 51 int c; 52 char *s; 53 54 ORIENT(stdin, -1); 55 for (s = buf, n--; (c = __sgetc(stdin)) != '\n' && n > 0 ; n--) { 56 if (c == EOF) { 57 if (s == buf) { 58 return (NULL); 59 } else 60 break; 61 } else 62 *s++ = c; 63 } 64 65 /* 66 * If end of buffer reached, discard until \n or eof. 67 * Then throw an error. 68 */ 69 if (n == 0) { 70 /* discard */ 71 while ((c = __sgetc(stdin)) != '\n' && c != EOF); 72 /* throw the error after lock released prior to exit */ 73 __throw_constraint_handler_s("gets_s : end of buffer", E2BIG); 74 return (NULL); 75 } 76 *s = 0; 77 return (buf); 78 } 79 80 /* ISO/IEC 9899:2011 K.3.7.4.1 */ 81 char * 82 gets_s(char *buf, rsize_t n) 83 { 84 char *ret; 85 if (buf == NULL) { 86 __throw_constraint_handler_s("gets_s : str is NULL", EINVAL); 87 return(NULL); 88 } else if (n > RSIZE_MAX) { 89 __throw_constraint_handler_s("gets_s : n > RSIZE_MAX", 90 EINVAL); 91 return(NULL); 92 } else if (n == 0) { 93 __throw_constraint_handler_s("gets_s : n == 0", EINVAL); 94 return(NULL); 95 } 96 97 #if 0 /* XXX */ 98 FLOCKFILE_CANCELSAFE(stdin); 99 #else 100 FLOCKFILE(stdin); 101 #endif 102 ret = _gets_s(buf, n); 103 #if 0 /* XXX */ 104 FUNLOCKFILE_CANCELSAFE(); 105 #else 106 FUNLOCKFILE(stdin); 107 #endif 108 return (ret); 109 } 110