1 /* $NetBSD: open.c,v 1.16 1997/01/28 09:41:03 pk Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)open.c 8.1 (Berkeley) 6/11/93 35 * 36 * 37 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 38 * All Rights Reserved. 39 * 40 * Author: Alessandro Forin 41 * 42 * Permission to use, copy, modify and distribute this software and its 43 * documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 50 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include "stand.h" 67 68 struct fs_ops *exclusive_file_system; 69 70 struct open_file files[SOPEN_MAX]; 71 72 static int 73 o_gethandle(void) 74 { 75 int fd; 76 77 for (fd = 0; fd < SOPEN_MAX; fd++) 78 if (files[fd].f_flags == 0) 79 return (fd); 80 return (-1); 81 } 82 83 static void 84 o_rainit(struct open_file *f) 85 { 86 f->f_rabuf = malloc(SOPEN_RASIZE); 87 f->f_ralen = 0; 88 f->f_raoffset = 0; 89 } 90 91 int 92 open(const char *fname, int mode) 93 { 94 struct fs_ops *fs; 95 struct open_file *f; 96 int fd, i, error, besterror; 97 const char *file; 98 99 TSENTER(); 100 101 if ((fd = o_gethandle()) == -1) { 102 errno = EMFILE; 103 return (-1); 104 } 105 106 f = &files[fd]; 107 f->f_flags = mode + 1; 108 f->f_dev = NULL; 109 f->f_ops = NULL; 110 f->f_offset = 0; 111 f->f_devdata = NULL; 112 file = NULL; 113 114 if (exclusive_file_system != NULL) { 115 fs = exclusive_file_system; 116 error = (fs->fo_open)(fname, f); 117 if (error == 0) 118 goto ok; 119 goto err; 120 } 121 122 error = devopen(f, fname, &file); 123 if (error || 124 (((f->f_flags & F_NODEV) == 0) && f->f_dev == NULL)) 125 goto err; 126 127 /* see if we opened a raw device; otherwise, 'file' is the file name. */ 128 if (file == NULL || *file == '\0') { 129 f->f_flags |= F_RAW; 130 f->f_rabuf = NULL; 131 TSEXIT(); 132 return (fd); 133 } 134 135 /* pass file name to the different filesystem open routines */ 136 besterror = ENOENT; 137 for (i = 0; file_system[i] != NULL; i++) { 138 fs = file_system[i]; 139 error = (fs->fo_open)(file, f); 140 if (error == 0) 141 goto ok; 142 if (error != EINVAL) 143 besterror = error; 144 } 145 error = besterror; 146 147 if ((f->f_flags & F_NODEV) == 0 && f->f_dev != NULL) 148 f->f_dev->dv_close(f); 149 if (error) 150 devclose(f); 151 152 err: 153 f->f_flags = 0; 154 errno = error; 155 TSEXIT(); 156 return (-1); 157 158 ok: 159 f->f_ops = fs; 160 o_rainit(f); 161 TSEXIT(); 162 return (fd); 163 } 164