1 /* $NetBSD: filedesc.h,v 1.25 2002/10/23 09:14:58 jdolecek Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 36 */ 37 38 #ifndef _SYS_FILEDESC_H_ 39 #define _SYS_FILEDESC_H_ 40 41 /* 42 * This structure is used for the management of descriptors. It may be 43 * shared by multiple processes. 44 * 45 * A process is initially started out with NDFILE descriptors stored within 46 * this structure, selected to be enough for typical applications based on 47 * the historical limit of 20 open files (and the usage of descriptors by 48 * shells). If these descriptors are exhausted, a larger descriptor table 49 * may be allocated, up to a process' resource limit; the internal arrays 50 * are then unused. The initial expansion is set to NDEXTENT; each time 51 * it runs out, it is doubled until the resource limit is reached. NDEXTENT 52 * should be selected to be the biggest multiple of OFILESIZE (see below) 53 * that will fit in a power-of-two sized piece of memory. 54 */ 55 #define NDFILE 20 56 #define NDEXTENT 50 /* 250 bytes in 256-byte alloc */ 57 58 struct filedesc { 59 struct file **fd_ofiles; /* file structures for open files */ 60 char *fd_ofileflags; /* per-process open file flags */ 61 int fd_nfiles; /* number of open files allocated */ 62 int fd_lastfile; /* high-water mark of fd_ofiles */ 63 int fd_freefile; /* approx. next free file */ 64 int fd_refcnt; /* reference count */ 65 66 int fd_knlistsize; /* size of fd_knlist */ 67 struct klist *fd_knlist; /* 68 * list of attached fd knotes, 69 * indexed by fd number 70 */ 71 u_long fd_knhashmask; /* size of fd_knhash */ 72 struct klist *fd_knhash; /* 73 * hash table for attached 74 * non-fd knotes 75 */ 76 }; 77 78 struct cwdinfo { 79 struct vnode *cwdi_cdir; /* current directory */ 80 struct vnode *cwdi_rdir; /* root directory */ 81 u_short cwdi_cmask; /* mask for file creation */ 82 u_short cwdi_refcnt; /* reference count */ 83 }; 84 85 86 /* 87 * Basic allocation of descriptors: 88 * one of the above, plus arrays for NDFILE descriptors. 89 */ 90 struct filedesc0 { 91 struct filedesc fd_fd; 92 /* 93 * These arrays are used when the number of open files is 94 * <= NDFILE, and are then pointed to by the pointers above. 95 */ 96 struct file *fd_dfiles[NDFILE]; 97 char fd_dfileflags[NDFILE]; 98 }; 99 100 /* 101 * Per-process open flags. 102 */ 103 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 104 105 /* 106 * Storage required per open file descriptor. 107 */ 108 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 109 110 #ifdef _KERNEL 111 /* 112 * Kernel global variables and routines. 113 */ 114 int dupfdopen(struct proc *p, int indx, int dfd, int mode, int error); 115 int fdalloc(struct proc *p, int want, int *result); 116 void fdexpand(struct proc *p); 117 int fdavail(struct proc *p, int n); 118 int falloc(struct proc *p, struct file **resultfp, int *resultfd); 119 void ffree(struct file *); 120 struct filedesc *fdcopy(struct proc *p); 121 struct filedesc *fdinit(struct proc *p); 122 void fdshare(struct proc *p1, struct proc *p2); 123 void fdunshare(struct proc *p); 124 void fdinit1(struct filedesc0 *newfdp); 125 void fdclear(struct proc *p); 126 void fdfree(struct proc *p); 127 void fdremove(struct filedesc *, int); 128 int fdrelease(struct proc *, int); 129 void fdcloseexec(struct proc *); 130 int fdcheckstd(struct proc *); 131 132 struct file *fd_getfile(struct filedesc *, int); 133 134 struct cwdinfo *cwdinit(struct proc *); 135 void cwdshare(struct proc *, struct proc *); 136 void cwdunshare(struct proc *); 137 void cwdfree(struct proc *); 138 139 int closef(struct file *, struct proc *); 140 int getsock(struct filedesc *, int, struct file **); 141 #endif /* _KERNEL */ 142 143 #endif /* !_SYS_FILEDESC_H_ */ 144