1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. 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 * From: @(#)open.c 8.1 (Berkeley) 6/11/93 37 * 38 * 39 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 40 * All Rights Reserved. 41 * 42 * Author: Alessandro Forin 43 * 44 * Permission to use, copy, modify and distribute this software and its 45 * documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 52 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $Id: open.c,v 1.4 1994/07/18 18:41:12 pk Exp $ 65 */ 66 67 #include "stand.h" 68 struct open_file files[SOPEN_MAX]; 69 70 /* 71 * File primitives proper 72 */ 73 74 int 75 open(fname, mode) 76 char *fname; 77 int mode; 78 { 79 register struct open_file *f; 80 register int fd, i, error; 81 char *file; 82 83 /* find a free file descriptor */ 84 for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++) 85 if (f->f_flags == 0) 86 goto fnd; 87 errno = EMFILE; 88 return (-1); 89 fnd: 90 /* 91 * Try to open the device. 92 * Convert open mode (0,1,2) to F_READ, F_WRITE. 93 */ 94 f->f_flags = mode + 1; 95 f->f_dev = (struct devsw *)0; 96 file = (char *)0; 97 error = devopen(f, fname, &file); 98 if (error || 99 (((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0)) 100 goto err; 101 102 /* see if we opened a raw device; otherwise, 'file' is the file name. */ 103 if (file == (char *)0) { 104 f->f_flags |= F_RAW; 105 return (0); 106 } 107 108 /* pass file name to the different filesystem open routines */ 109 for (i = 0; i < nfsys; i++) { 110 /* convert mode (0,1,2) to FREAD, FWRITE. */ 111 error = (file_system[i].open)(file, f); 112 if (error == 0) { 113 f->f_ops = &file_system[i]; 114 return (fd); 115 } 116 } 117 if (!error) 118 error = ENOENT; 119 120 err: 121 f->f_flags = 0; 122 errno = error; 123 return (-1); 124 } 125 126 /* 127 * Null filesystem 128 */ 129 int null_open (char *path, struct open_file *f) 130 { 131 errno = EIO; 132 return -1; 133 } 134 135 int null_close(struct open_file *f) 136 { 137 return 0; 138 } 139 140 int null_read (struct open_file *f, char *buf, u_int size, u_int *resid) 141 { 142 errno = EIO; 143 return -1; 144 } 145 146 int null_write (struct open_file *f, char *buf, u_int size, u_int *resid) 147 { 148 errno = EIO; 149 return -1; 150 } 151 152 off_t null_seek (struct open_file *f, off_t offset, int where) 153 { 154 errno = EIO; 155 return -1; 156 } 157 158 int null_stat (struct open_file *f, struct stat *sb) 159 { 160 errno = EIO; 161 return -1; 162 } 163 164