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 37 #include "namespace.h" 38 #include <errno.h> 39 #include <unistd.h> 40 #include <stdint.h> 41 #include <stdio.h> 42 #include "un-namespace.h" 43 #include "libc_private.h" 44 #include "local.h" 45 46 static inline char * 47 _gets_s(char *buf, rsize_t n) 48 { 49 int c; 50 char *s; 51 52 ORIENT(stdin, -1); 53 for (s = buf, n--; (c = __sgetc(stdin)) != '\n' && n > 0 ; n--) { 54 if (c == EOF) { 55 if (s == buf) { 56 return (NULL); 57 } else 58 break; 59 } else 60 *s++ = c; 61 } 62 63 /* 64 * If end of buffer reached, discard until \n or eof. 65 * Then throw an error. 66 */ 67 if (n == 0) { 68 /* discard */ 69 while ((c = __sgetc(stdin)) != '\n' && c != EOF); 70 /* throw the error after lock released prior to exit */ 71 __throw_constraint_handler_s("gets_s : end of buffer", E2BIG); 72 return (NULL); 73 } 74 *s = 0; 75 return (buf); 76 } 77 78 /* ISO/IEC 9899:2011 K.3.7.4.1 */ 79 char * 80 gets_s(char *buf, rsize_t n) 81 { 82 char *ret; 83 if (buf == NULL) { 84 __throw_constraint_handler_s("gets_s : str is NULL", EINVAL); 85 return(NULL); 86 } else if (n > RSIZE_MAX) { 87 __throw_constraint_handler_s("gets_s : n > RSIZE_MAX", 88 EINVAL); 89 return(NULL); 90 } else if (n == 0) { 91 __throw_constraint_handler_s("gets_s : n == 0", EINVAL); 92 return(NULL); 93 } 94 95 FLOCKFILE_CANCELSAFE(stdin); 96 ret = _gets_s(buf, n); 97 FUNLOCKFILE_CANCELSAFE(); 98 return (ret); 99 } 100