1 /* $NetBSD: open.c,v 1.12 1996/09/30 16:01:21 ws 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)open.c 8.1 (Berkeley) 6/11/93 39 * 40 * 41 * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 42 * All Rights Reserved. 43 * 44 * Author: Alessandro Forin 45 * 46 * Permission to use, copy, modify and distribute this software and its 47 * documentation is hereby granted, provided that both the copyright 48 * notice and this permission notice appear in all copies of the 49 * software, derivative works or modified versions, and any portions 50 * thereof, and that both notices appear in supporting documentation. 51 * 52 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 53 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 54 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 55 * 56 * Carnegie Mellon requests users of this software to return to 57 * 58 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 59 * School of Computer Science 60 * Carnegie Mellon University 61 * Pittsburgh PA 15213-3890 62 * 63 * any improvements or extensions that they make and grant Carnegie the 64 * rights to redistribute these changes. 65 */ 66 67 #include "stand.h" 68 69 struct open_file files[SOPEN_MAX]; 70 71 /* 72 * File primitives proper 73 */ 74 75 int 76 open(fname, mode) 77 const char *fname; 78 int mode; 79 { 80 register struct open_file *f; 81 register int fd, i, error; 82 char *file; 83 84 /* find a free file descriptor */ 85 for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++) 86 if (f->f_flags == 0) 87 goto fnd; 88 errno = EMFILE; 89 return (-1); 90 fnd: 91 /* 92 * Try to open the device. 93 * Convert open mode (0,1,2) to F_READ, F_WRITE. 94 */ 95 f->f_flags = mode + 1; 96 f->f_dev = (struct devsw *)0; 97 f->f_ops = (struct fs_ops *)0; 98 file = (char *)0; 99 error = devopen(f, fname, &file); 100 if (error || 101 (((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0)) 102 goto err; 103 104 /* see if we opened a raw device; otherwise, 'file' is the file name. */ 105 if (file == (char *)0 || *file == '\0') { 106 f->f_flags |= F_RAW; 107 return (fd); 108 } 109 110 /* pass file name to the different filesystem open routines */ 111 for (i = 0; i < nfsys; i++) { 112 /* convert mode (0,1,2) to FREAD, FWRITE. */ 113 error = (file_system[i].open)(file, f); 114 if (error == 0) { 115 f->f_ops = &file_system[i]; 116 return (fd); 117 } 118 } 119 if (!error) 120 error = ENOENT; 121 122 f->f_dev->dv_close(f); 123 err: 124 f->f_flags = 0; 125 errno = error; 126 return (-1); 127 } 128