bsd/sys/filedesc.h

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1990, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)filedesc.h  8.1 (Berkeley) 6/2/93
  62  */
  63
  64 #ifndef _SYS_FILEDESC_H_
  65 #define _SYS_FILEDESC_H_
  66
  67 #include <sys/appleapiopts.h>
  68
  69 /*
  70  * This structure is used for the management of descriptors.  It may be
  71  * shared by multiple processes.
  72  *
  73  * A process is initially started out with NDFILE descriptors [XXXstored within
  74  * this structureXXX], selected to be enough for typical applications based on
  75  * the historical limit of 20 open files (and the usage of descriptors by
  76  * shells).  If these descriptors are exhausted, a larger descriptor table
  77  * may be allocated, up to a process' resource limit; [XXXthe internal arrays
  78  * are then unusedXXX].  The initial expansion is set to NDEXTENT; each time
  79  * it runs out, it is doubled until the resource limit is reached. NDEXTENT
  80  * should be selected to be the biggest multiple of OFILESIZE (see below)
  81  * that will fit in a power-of-two sized piece of memory.
  82  */
  83 #define NDFILE          25              /* 125 bytes */
  84 #define NDEXTENT        50              /* 250 bytes in 256-byte alloc. */
  85
  86 #ifdef BSD_KERNEL_PRIVATE
  87
  88 struct klist;
  89
  90 struct filedesc {
  91         struct  fileproc **fd_ofiles;   /* file structures for open files */
  92         char    *fd_ofileflags;         /* per-process open file flags */
  93         struct  vnode *fd_cdir;         /* current directory */
  94         struct  vnode *fd_rdir;         /* root directory */
  95         int     fd_nfiles;              /* number of open files allocated */
  96         int     fd_lastfile;            /* high-water mark of fd_ofiles */
  97         int     fd_freefile;            /* approx. next free file */
  98         u_short fd_cmask;               /* mask for file creation */
  99         uint32_t        fd_refcnt;              /* reference count */
 100
 101         int     fd_knlistsize;          /* size of knlist */
 102         struct  klist *fd_knlist;       /* list of attached knotes */
 103         u_long  fd_knhashmask;          /* size of knhash */
 104         struct  klist *fd_knhash;       /* hash table for attached knotes */
 105         int     fd_flags;
 106 };
 107
 108 /*
 109  * definitions for fd_flags;
 110  */
 111 #define FD_CHROOT       0x01    /* process was chrooted... keep track even */
 112                                 /* if we're force unmounted and unable to */
 113                                 /* take a vnode_ref on fd_rdir during a fork */
 114
 115 /*
 116  * Per-process open flags.
 117  */
 118 #define UF_EXCLOSE      0x01            /* auto-close on exec */
 119 #define UF_RESERVED     0x04            /* open pending / in progress */
 120 #define UF_CLOSING      0x08            /* close in progress */
 121
 122 #ifdef KERNEL
 123 #define UF_RESVWAIT     0x10            /* close in progress */
 124 #define UF_INHERIT      0x20            /* "inherit-on-exec" */
 125 #define UF_VALID_FLAGS  \
 126         (UF_EXCLOSE | UF_RESERVED | UF_CLOSING | UF_RESVWAIT | UF_INHERIT)
 127 #endif /* KERNEL */
 128
 129 /*
 130  * Storage required per open file descriptor.
 131  */
 132 #define OFILESIZE (sizeof(struct file *) + sizeof(char))
 133
 134 #ifdef KERNEL
 135 /*
 136  * Kernel global variables and routines.
 137  */
 138 extern int      dupfdopen(struct filedesc *fdp,
 139                                 int indx, int dfd, int mode, int error);
 140 extern int      fdalloc(proc_t p, int want, int *result);
 141 extern void     fdrelse(proc_t p, int fd);
 142 extern int      fdavail(proc_t p, int n);
 143 #define         fdfile(p, fd)                                   \
 144                         (&(p)->p_fd->fd_ofiles[(fd)])
 145 #define         fdflags(p, fd)                                  \
 146                         (&(p)->p_fd->fd_ofileflags[(fd)])
 147 extern int      falloc(proc_t p, struct fileproc **resultfp, int *resultfd, vfs_context_t ctx);
 148 extern void     ffree(struct file *fp);
 149
 150 #ifdef __APPLE_API_PRIVATE
 151 extern struct   filedesc *fdcopy(proc_t p, struct vnode *uth_cdir);
 152 extern void     fdfree(proc_t p);
 153 extern void     fdexec(proc_t p, short flags);
 154 #endif /* __APPLE_API_PRIVATE */
 155
 156 #endif /* KERNEL */
 157
 158 #endif /* BSD_KERNEL_PRIVATE */
 159
 160 #endif /* !_SYS_FILEDESC_H_ */