160 lines
4.6 KiB
C
160 lines
4.6 KiB
C
/* $NetBSD: open.c,v 1.16 1997/01/28 09:41:03 pk Exp $ */
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/*-
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* Copyright (c) 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* The Mach Operating System project at Carnegie-Mellon University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)open.c 8.1 (Berkeley) 6/11/93
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*
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*
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* Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
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* All Rights Reserved.
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*
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* Author: Alessandro Forin
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "stand.h"
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struct fs_ops *exclusive_file_system;
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struct open_file files[SOPEN_MAX];
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static int
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o_gethandle(void)
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{
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int fd;
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for (fd = 0; fd < SOPEN_MAX; fd++)
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if (files[fd].f_flags == 0)
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return(fd);
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return(-1);
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}
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static void
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o_rainit(struct open_file *f)
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{
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f->f_rabuf = malloc(SOPEN_RASIZE);
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f->f_ralen = 0;
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f->f_raoffset = 0;
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}
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int
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open(const char *fname, int mode)
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{
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struct fs_ops *fs;
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struct open_file *f;
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int fd, i, error, besterror;
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const char *file;
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if ((fd = o_gethandle()) == -1) {
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errno = EMFILE;
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return(-1);
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}
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f = &files[fd];
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f->f_flags = mode + 1;
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f->f_dev = (struct devsw *)0;
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f->f_ops = (struct fs_ops *)0;
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f->f_offset = 0;
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f->f_devdata = NULL;
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file = (char *)0;
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if (exclusive_file_system != NULL) {
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fs = exclusive_file_system;
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error = (fs->fo_open)(fname, f);
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if (error == 0)
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goto ok;
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goto err;
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}
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error = devopen(f, fname, &file);
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if (error ||
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(((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0))
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goto err;
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/* see if we opened a raw device; otherwise, 'file' is the file name. */
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if (file == (char *)0 || *file == '\0') {
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f->f_flags |= F_RAW;
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f->f_rabuf = NULL;
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return (fd);
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}
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/* pass file name to the different filesystem open routines */
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besterror = ENOENT;
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for (i = 0; file_system[i] != NULL; i++) {
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fs = file_system[i];
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error = (fs->fo_open)(file, f);
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if (error == 0)
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goto ok;
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if (error != EINVAL)
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besterror = error;
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}
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error = besterror;
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fail:
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if ((f->f_flags & F_NODEV) == 0 && f->f_dev != NULL)
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f->f_dev->dv_close(f);
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if (error)
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devclose(f);
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err:
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f->f_flags = 0;
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errno = error;
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return (-1);
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ok:
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f->f_ops = fs;
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o_rainit(f);
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return (fd);
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}
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