bsd/sys/file.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *      @(#)file.h      8.3 (Berkeley) 1/9/95
  56  */
  57
  58 #ifndef _SYS_FILE_H_
  59 #define _SYS_FILE_H_
  60
  61 #include <sys/fcntl.h>
  62 #include <sys/unistd.h>
  63
  64 #ifdef KERNEL
  65 #include <sys/queue.h>
  66 #include <sys/cdefs.h>
  67
  68 struct proc;
  69 struct uio;
  70
  71 /*
  72  * Kernel descriptor table.
  73  * One entry for each open kernel vnode and socket.
  74  */
  75 struct file {
  76         LIST_ENTRY(file) f_list;/* list of active files */
  77         short   f_flag;         /* see fcntl.h */
  78 #define DTYPE_VNODE     1       /* file */
  79 #define DTYPE_SOCKET    2       /* communications endpoint */
  80 #define DTYPE_PSXSHM    3       /* POSIX Shared memory */
  81 #define DTYPE_PSXSEM    4       /* POSIX Semaphores */
  82         short   f_type;         /* descriptor type */
  83         short   f_count;        /* reference count */
  84         short   f_msgcount;     /* references from message queue */
  85         struct  ucred *f_cred;  /* credentials associated with descriptor */
  86         struct  fileops {
  87                 int     (*fo_read)      __P((struct file *fp, struct uio *uio,
  88                                             struct ucred *cred));
  89                 int     (*fo_write)     __P((struct file *fp, struct uio *uio,
  90                                             struct ucred *cred));
  91                 int     (*fo_ioctl)     __P((struct file *fp, u_long com,
  92                                             caddr_t data, struct proc *p));
  93                 int     (*fo_select)    __P((struct file *fp, int which,
  94                                             struct proc *p));
  95                 int     (*fo_close)     __P((struct file *fp, struct proc *p));
  96         } *f_ops;
  97         off_t   f_offset;
  98         caddr_t f_data;         /* vnode or socket */
  99 };
 100
 101 LIST_HEAD(filelist, file);
 102 extern struct filelist filehead;        /* head of list of open files */
 103 extern int maxfiles;                    /* kernel limit on number of open files */
 104 extern int nfiles;                      /* actual number of open files */
 105
 106 __BEGIN_DECLS
 107 int fref __P((struct file *));  /* take a reference on file pointer */
 108 int frele __P((struct file *)); /* release a reference on file pointer */
 109 int fcount __P((struct file *));        /* returns the reference count */
 110 __END_DECLS
 111
 112 #endif /* KERNEL */
 113
 114 #endif /* !_SYS_FILE_H_ */