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open.c revision 1.22
      1 /*	$NetBSD: open.c,v 1.22 2003/02/01 14:54:22 dsl 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 (at) 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 /*
     70  *	File primitives proper
     71  */
     72 
     73 #ifdef HELLO_CTAGS
     74 oopen(){}
     75 #endif
     76 
     77 int
     78 #ifndef __INTERNAL_LIBSA_CREAD
     79 open(fname, mode)
     80 #else
     81 oopen(fname, mode)
     82 #endif
     83 	const char *fname;
     84 	int mode;
     85 {
     86 	struct open_file *f;
     87 	int fd, error;
     88 #if !defined(LIBSA_SINGLE_FILESYSTEM)
     89 	int i, besterror;
     90 #endif
     91 	char *file;
     92 
     93 	/* find a free file descriptor */
     94 	for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++)
     95 		if (f->f_flags == 0)
     96 			goto fnd;
     97 	errno = EMFILE;
     98 	return (-1);
     99 fnd:
    100 	/*
    101 	 * Try to open the device.
    102 	 * Convert open mode (0,1,2) to F_READ, F_WRITE.
    103 	 */
    104 	f->f_flags = mode + 1;
    105 #if !defined(LIBSA_SINGLE_DEVICE)
    106 	f->f_dev = (struct devsw *)0;
    107 #endif
    108 #if !defined(LIBSA_SINGLE_FILESYSTEM)
    109 	f->f_ops = (struct fs_ops *)0;
    110 #endif
    111 #if !defined(LIBSA_NO_RAW_ACCESS)
    112 	f->f_offset = 0;
    113 #endif
    114 	file = (char *)0;
    115 	error = devopen(f, fname, &file);
    116 	if (error
    117 #if !defined(LIBSA_SINGLE_DEVICE)
    118 	    || (((f->f_flags & F_NODEV) == 0) &&
    119 		f->f_dev == (struct devsw *)0)
    120 #endif
    121 	    )
    122 		goto err;
    123 
    124 #if !defined(LIBSA_NO_RAW_ACCESS)
    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 		return (fd);
    129 	}
    130 #endif
    131 
    132 	/* pass file name to the different filesystem open routines */
    133 #if !defined(LIBSA_SINGLE_FILESYSTEM)
    134 	besterror = ENOENT;
    135 	for (i = 0; i < nfsys; i++) {
    136 		error = FS_OPEN(&file_system[i])(file, f);
    137 		if (error == 0) {
    138 			f->f_ops = &file_system[i];
    139 			return (fd);
    140 		}
    141 		if (error != EINVAL)
    142 			besterror = error;
    143 	}
    144 	error = besterror;
    145 #else
    146 	error = FS_OPEN(&file_system[i])(file, f);
    147 	if (error == 0)
    148 		return (fd);
    149 	if (error == EINVAL)
    150 		error = ENOENT;
    151 #endif
    152 
    153 	if ((f->f_flags & F_NODEV) == 0) {
    154 #if !defined(LIBSA_SINGLE_DEVICE)
    155 		if (DEV_CLOSE(f->f_dev) != NULL)
    156 #endif
    157 			(void)DEV_CLOSE(f->f_dev)(f);
    158 	}
    159 err:
    160 	f->f_flags = 0;
    161 	errno = error;
    162 	return (-1);
    163 }
    164