sys/lib/libsa/open.c

   1 /*      $NetBSD: open.c,v 1.26 2007/11/24 13:20:56 isaki 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 "stand.h"
  64
  65 /*
  66  *      File primitives proper
  67  */
  68
  69 #ifdef HELLO_CTAGS
  70 oopen(){}
  71 #endif
  72
  73 int
  74 #ifndef __INTERNAL_LIBSA_CREAD
  75 open(const char *fname, int mode)
  76 #else
  77 oopen(const char *fname, int mode)
  78 #endif
  79 {
  80         struct open_file *f;
  81         int fd, error;
  82 #if !defined(LIBSA_SINGLE_FILESYSTEM)
  83         int i, besterror;
  84 #endif
  85         char *file;
  86
  87         /* find a free file descriptor */
  88         for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++)
  89                 if (f->f_flags == 0)
  90                         goto fnd;
  91         errno = EMFILE;
  92         return -1;
  93 fnd:
  94         /*
  95          * Try to open the device.
  96          * Convert open mode (0,1,2) to F_READ, F_WRITE.
  97          */
  98         f->f_flags = mode + 1;
  99 #if !defined(LIBSA_SINGLE_DEVICE)
 100         f->f_dev = (struct devsw *)0;
 101 #endif
 102 #if !defined(LIBSA_SINGLE_FILESYSTEM)
 103         f->f_ops = (struct fs_ops *)0;
 104 #endif
 105 #if !defined(LIBSA_NO_RAW_ACCESS)
 106         f->f_offset = 0;
 107 #endif
 108         file = (char *)0;
 109         error = devopen(f, fname, &file);
 110         if (error
 111 #if !defined(LIBSA_SINGLE_DEVICE)
 112             || (((f->f_flags & F_NODEV) == 0) &&
 113                 f->f_dev == (struct devsw *)0)
 114 #endif
 115             )
 116                 goto err;
 117
 118 #if !defined(LIBSA_NO_RAW_ACCESS)
 119         /* see if we opened a raw device; otherwise, 'file' is the file name. */
 120         if (file == (char *)0 || *file == '\0') {
 121                 f->f_flags |= F_RAW;
 122                 return fd;
 123         }
 124 #endif
 125
 126         /* pass file name to the different filesystem open routines */
 127 #if !defined(LIBSA_SINGLE_FILESYSTEM)
 128         besterror = ENOENT;
 129         for (i = 0; i < nfsys; i++) {
 130                 error = FS_OPEN(&file_system[i])(file, f);
 131                 if (error == 0) {
 132                         f->f_ops = &file_system[i];
 133                         return fd;
 134                 }
 135                 if (error != EINVAL)
 136                         besterror = error;
 137         }
 138         error = besterror;
 139 #else
 140         error = FS_OPEN(&file_system[i])(file, f);
 141         if (error == 0)
 142                 return fd;
 143         if (error == EINVAL)
 144                 error = ENOENT;
 145 #endif
 146
 147         if ((f->f_flags & F_NODEV) == 0) {
 148 #if !defined(LIBSA_SINGLE_DEVICE)
 149                 if (DEV_CLOSE(f->f_dev) != NULL)
 150 #endif
 151                         (void)DEV_CLOSE(f->f_dev)(f);
 152         }
 153 err:
 154         f->f_flags = 0;
 155         errno = error;
 156         return -1;
 157 }