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 if ((fd = o_gethandle()) == -1) { 100 errno = EMFILE; 101 return(-1); 102 } 103 104 f = &files[fd]; 105 f->f_flags = mode + 1; 106 f->f_dev = (struct devsw *)0; 107 f->f_ops = (struct fs_ops *)0; 108 f->f_offset = 0; 109 f->f_devdata = NULL; 110 file = (char *)0; 111 112 if (exclusive_file_system != NULL) { 113 fs = exclusive_file_system; 114 error = (fs->fo_open)(fname, f); 115 if (error == 0) 116 goto ok; 117 goto err; 118 } 119 120 error = devopen(f, fname, &file); 121 if (error || 122 (((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0)) 123 goto err; 124 125 /* see if we opened a raw device; otherwise, 'file' is the file name. */ 126 if (file == (char *)0 || *file == '\0') { 127 f->f_flags |= F_RAW; 128 f->f_rabuf = NULL; 129 return (fd); 130 } 131 132 /* pass file name to the different filesystem open routines */ 133 besterror = ENOENT; 134 for (i = 0; file_system[i] != NULL; i++) { 135 fs = file_system[i]; 136 error = (fs->fo_open)(file, f); 137 if (error == 0) 138 goto ok; 139 if (error != EINVAL) 140 besterror = error; 141 } 142 error = besterror; 143 144 fail: 145 if ((f->f_flags & F_NODEV) == 0 && f->f_dev != NULL) 146 f->f_dev->dv_close(f); 147 if (error) 148 devclose(f); 149 150 err: 151 f->f_flags = 0; 152 errno = error; 153 return (-1); 154 155 ok: 156 f->f_ops = fs; 157 o_rainit(f); 158 return (fd); 159 } 160