open.c revision 38451
138451Smsmith/* $NetBSD: open.c,v 1.16 1997/01/28 09:41:03 pk Exp $ */ 238451Smsmith 338451Smsmith/*- 438451Smsmith * Copyright (c) 1993 538451Smsmith * The Regents of the University of California. All rights reserved. 638451Smsmith * 738451Smsmith * This code is derived from software contributed to Berkeley by 838451Smsmith * The Mach Operating System project at Carnegie-Mellon University. 938451Smsmith * 1038451Smsmith * Redistribution and use in source and binary forms, with or without 1138451Smsmith * modification, are permitted provided that the following conditions 1238451Smsmith * are met: 1338451Smsmith * 1. Redistributions of source code must retain the above copyright 1438451Smsmith * notice, this list of conditions and the following disclaimer. 1538451Smsmith * 2. Redistributions in binary form must reproduce the above copyright 1638451Smsmith * notice, this list of conditions and the following disclaimer in the 1738451Smsmith * documentation and/or other materials provided with the distribution. 1838451Smsmith * 3. All advertising materials mentioning features or use of this software 1938451Smsmith * must display the following acknowledgement: 2038451Smsmith * This product includes software developed by the University of 2138451Smsmith * California, Berkeley and its contributors. 2238451Smsmith * 4. Neither the name of the University nor the names of its contributors 2338451Smsmith * may be used to endorse or promote products derived from this software 2438451Smsmith * without specific prior written permission. 2538451Smsmith * 2638451Smsmith * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2738451Smsmith * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2838451Smsmith * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2938451Smsmith * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 3038451Smsmith * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 3138451Smsmith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3238451Smsmith * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3338451Smsmith * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3438451Smsmith * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3538451Smsmith * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3638451Smsmith * SUCH DAMAGE. 3738451Smsmith * 3838451Smsmith * @(#)open.c 8.1 (Berkeley) 6/11/93 3938451Smsmith * 4038451Smsmith * 4138451Smsmith * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University 4238451Smsmith * All Rights Reserved. 4338451Smsmith * 4438451Smsmith * Author: Alessandro Forin 4538451Smsmith * 4638451Smsmith * Permission to use, copy, modify and distribute this software and its 4738451Smsmith * documentation is hereby granted, provided that both the copyright 4838451Smsmith * notice and this permission notice appear in all copies of the 4938451Smsmith * software, derivative works or modified versions, and any portions 5038451Smsmith * thereof, and that both notices appear in supporting documentation. 5138451Smsmith * 5238451Smsmith * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 5338451Smsmith * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 5438451Smsmith * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 5538451Smsmith * 5638451Smsmith * Carnegie Mellon requests users of this software to return to 5738451Smsmith * 5838451Smsmith * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 5938451Smsmith * School of Computer Science 6038451Smsmith * Carnegie Mellon University 6138451Smsmith * Pittsburgh PA 15213-3890 6238451Smsmith * 6338451Smsmith * any improvements or extensions that they make and grant Carnegie the 6438451Smsmith * rights to redistribute these changes. 6538451Smsmith */ 6638451Smsmith 6738451Smsmith#include "stand.h" 6838451Smsmith 6938451Smsmithstruct open_file files[SOPEN_MAX]; 7038451Smsmith 7138451Smsmithstatic int 7238451Smsmitho_gethandle(void) 7338451Smsmith{ 7438451Smsmith int fd; 7538451Smsmith 7638451Smsmith for (fd = 0; fd < SOPEN_MAX; fd++) 7738451Smsmith if (files[fd].f_flags == 0) 7838451Smsmith return(fd); 7938451Smsmith return(-1); 8038451Smsmith} 8138451Smsmith 8238451Smsmith 8338451Smsmithint 8438451Smsmithopen(const char *fname, int mode) 8538451Smsmith{ 8638451Smsmith struct open_file *f; 8738451Smsmith int fd, i, error, besterror; 8838451Smsmith char *file; 8938451Smsmith 9038451Smsmith if ((fd = o_gethandle()) == -1) { 9138451Smsmith errno = EMFILE; 9238451Smsmith return(-1); 9338451Smsmith } 9438451Smsmith 9538451Smsmith f = &files[fd]; 9638451Smsmith f->f_flags = mode + 1; 9738451Smsmith f->f_dev = (struct devsw *)0; 9838451Smsmith f->f_ops = (struct fs_ops *)0; 9938451Smsmith f->f_offset = 0; 10038451Smsmith f->f_devdata = NULL; 10138451Smsmith file = (char *)0; 10238451Smsmith error = devopen(f, fname, &file); 10338451Smsmith if (error || 10438451Smsmith (((f->f_flags & F_NODEV) == 0) && f->f_dev == (struct devsw *)0)) 10538451Smsmith goto err; 10638451Smsmith 10738451Smsmith /* see if we opened a raw device; otherwise, 'file' is the file name. */ 10838451Smsmith if (file == (char *)0 || *file == '\0') { 10938451Smsmith f->f_flags |= F_RAW; 11038451Smsmith return (fd); 11138451Smsmith } 11238451Smsmith 11338451Smsmith /* pass file name to the different filesystem open routines */ 11438451Smsmith besterror = ENOENT; 11538451Smsmith for (i = 0; file_system[i] != NULL; i++) { 11638451Smsmith 11738451Smsmith error = ((*file_system[i]).fo_open)(file, f); 11838451Smsmith if (error == 0) { 11938451Smsmith 12038451Smsmith f->f_ops = file_system[i]; 12138451Smsmith return (fd); 12238451Smsmith } 12338451Smsmith if (error != EINVAL) 12438451Smsmith besterror = error; 12538451Smsmith } 12638451Smsmith error = besterror; 12738451Smsmith 12838451Smsmith if ((f->f_flags & F_NODEV) == 0) 12938451Smsmith f->f_dev->dv_close(f); 13038451Smsmith if (error) 13138451Smsmith devclose(f); 13238451Smsmith 13338451Smsmith err: 13438451Smsmith f->f_flags = 0; 13538451Smsmith errno = error; 13638451Smsmith return (-1); 13738451Smsmith} 138