1 /* 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 34 * $FreeBSD: src/sys/sys/filedesc.h,v 1.19.2.5 2003/06/06 20:21:32 tegge Exp $ 35 * $DragonFly: src/sys/sys/filedesc.h,v 1.2 2003/06/17 04:28:58 dillon Exp $ 36 */ 37 38 #ifndef _SYS_FILEDESC_H_ 39 #define _SYS_FILEDESC_H_ 40 41 #include <sys/queue.h> 42 43 /* 44 * This structure is used for the management of descriptors. It may be 45 * shared by multiple processes. 46 * 47 * A process is initially started out with NDFILE descriptors stored within 48 * this structure, selected to be enough for typical applications based on 49 * the historical limit of 20 open files (and the usage of descriptors by 50 * shells). If these descriptors are exhausted, a larger descriptor table 51 * may be allocated, up to a process' resource limit; the internal arrays 52 * are then unused. The initial expansion is set to NDEXTENT; each time 53 * it runs out, it is doubled until the resource limit is reached. NDEXTENT 54 * should be selected to be the biggest multiple of OFILESIZE (see below) 55 * that will fit in a power-of-two sized piece of memory. 56 */ 57 #define NDFILE 20 58 #define NDEXTENT 50 /* 250 bytes in 256-byte alloc. */ 59 60 struct klist; 61 62 struct filedesc { 63 struct file **fd_ofiles; /* file structures for open files */ 64 char *fd_ofileflags; /* per-process open file flags */ 65 struct vnode *fd_cdir; /* current directory */ 66 struct vnode *fd_rdir; /* root directory */ 67 struct vnode *fd_jdir; /* jail root directory */ 68 int fd_nfiles; /* number of open files allocated */ 69 u_short fd_lastfile; /* high-water mark of fd_ofiles */ 70 u_short fd_freefile; /* approx. next free file */ 71 u_short fd_cmask; /* mask for file creation */ 72 u_short fd_refcnt; /* reference count */ 73 74 int fd_knlistsize; /* size of knlist */ 75 struct klist *fd_knlist; /* list of attached knotes */ 76 u_long fd_knhashmask; /* size of knhash */ 77 struct klist *fd_knhash; /* hash table for attached knotes */ 78 int fd_holdleaderscount; /* block fdfree() for shared close() */ 79 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 80 }; 81 82 /* 83 * Basic allocation of descriptors: 84 * one of the above, plus arrays for NDFILE descriptors. 85 */ 86 struct filedesc0 { 87 struct filedesc fd_fd; 88 /* 89 * These arrays are used when the number of open files is 90 * <= NDFILE, and are then pointed to by the pointers above. 91 */ 92 struct file *fd_dfiles[NDFILE]; 93 char fd_dfileflags[NDFILE]; 94 }; 95 96 97 98 /* 99 * Structure to keep track of (process leader, struct fildedesc) tuples. 100 * Each process has a pointer to such a structure when detailed tracking 101 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor 102 * table to be shared by processes having different "p_leader" pointers 103 * and thus distinct POSIX style locks. 104 */ 105 struct filedesc_to_leader { 106 int fdl_refcount; /* references from struct proc */ 107 int fdl_holdcount; /* temporary hold during closef */ 108 int fdl_wakeup; /* fdfree() waits on closef() */ 109 struct proc *fdl_leader; /* owner of POSIX locks */ 110 /* Circular list */ 111 struct filedesc_to_leader *fdl_prev; 112 struct filedesc_to_leader *fdl_next; 113 }; 114 115 /* 116 * Per-process open flags. 117 */ 118 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 119 #if 0 120 #define UF_MAPPED 0x02 /* mapped from device */ 121 #endif 122 123 /* 124 * Storage required per open file descriptor. 125 */ 126 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 127 128 /* 129 * This structure that holds the information needed to send a SIGIO or 130 * a SIGURG signal to a process or process group when new data arrives 131 * on a device or socket. The structure is placed on an SLIST belonging 132 * to the proc or pgrp so that the entire list may be revoked when the 133 * process exits or the process group disappears. 134 */ 135 struct sigio { 136 union { 137 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */ 138 struct pgrp *siu_pgrp; /* process group to receive ... */ 139 } sio_u; 140 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */ 141 struct sigio **sio_myref; /* location of the pointer that holds 142 * the reference to this structure */ 143 struct ucred *sio_ucred; /* current credentials */ 144 uid_t sio_ruid; /* real user id */ 145 pid_t sio_pgid; /* pgid for signals */ 146 }; 147 #define sio_proc sio_u.siu_proc 148 #define sio_pgrp sio_u.siu_pgrp 149 150 SLIST_HEAD(sigiolst, sigio); 151 152 #ifdef _KERNEL 153 /* 154 * Kernel global variables and routines. 155 */ 156 int dupfdopen __P((struct proc *, struct filedesc *, int, int, int, int)); 157 int fdalloc __P((struct proc *p, int want, int *result)); 158 int fdavail __P((struct proc *p, int n)); 159 int falloc __P((struct proc *p, struct file **resultfp, int *resultfd)); 160 void ffree __P((struct file *)); 161 struct filedesc *fdinit __P((struct proc *p)); 162 struct filedesc *fdshare __P((struct proc *p)); 163 struct filedesc *fdcopy __P((struct proc *p)); 164 void fdfree __P((struct proc *p)); 165 int closef __P((struct file *fp,struct proc *p)); 166 void fdcloseexec __P((struct proc *p)); 167 int fdcheckstd __P((struct proc *p)); 168 struct file *holdfp __P((struct filedesc* fdp, int fd, int flag)); 169 int getvnode __P((struct filedesc *fdp, int fd, struct file **fpp)); 170 int fdissequential __P((struct file *)); 171 void fdsequential __P((struct file *, int)); 172 pid_t fgetown __P((struct sigio *)); 173 int fsetown __P((pid_t, struct sigio **)); 174 void funsetown __P((struct sigio *)); 175 void funsetownlst __P((struct sigiolst *)); 176 void setugidsafety __P((struct proc *p)); 177 178 struct filedesc_to_leader * 179 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 180 struct proc *leader); 181 182 #endif 183 184 #endif 185