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 1.11 2005/06/22 01:33:22 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) and the constraint of being one less than a power of 2. 51 * If these descriptors are exhausted, a larger descriptor table 52 * may be allocated, up to a process' resource limit; the internal arrays 53 * are then unused. Each time the file table runs out, it is doubled until 54 * the resource limit is reached. 55 */ 56 #define NDFILE 15 /* must be of the form 2^n - 1 */ 57 58 struct file; 59 struct klist; 60 struct namecache; 61 62 struct fdnode { 63 struct file *fp; 64 char fileflags; 65 char unused01; 66 char unused02; 67 char unused03; 68 int allocated; 69 }; 70 71 struct filedesc { 72 struct fdnode *fd_files; /* file structures for open files */ 73 struct vnode *fd_cdir; /* current directory (phaseout) */ 74 struct vnode *fd_rdir; /* root directory (phaseout) */ 75 struct vnode *fd_jdir; /* jail root directory (phaseout) */ 76 struct namecache *fd_ncdir; /* current directory */ 77 struct namecache *fd_nrdir; /* root directory */ 78 struct namecache *fd_njdir; /* jail directory */ 79 int fd_nfiles; /* number of open files allocated */ 80 int fd_lastfile; /* high-water mark of fd_files */ 81 int fd_freefile; /* approx. next free file */ 82 int fd_cmask; /* mask for file creation */ 83 int fd_refcnt; /* reference count */ 84 85 int fd_knlistsize; /* size of knlist */ 86 struct klist *fd_knlist; /* list of attached knotes */ 87 u_long fd_knhashmask; /* size of knhash */ 88 struct klist *fd_knhash; /* hash table for attached knotes */ 89 int fd_holdleaderscount; /* block fdfree() for shared close() */ 90 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 91 struct fdnode fd_builtin_files[NDFILE]; 92 }; 93 94 /* 95 * Structure to keep track of (process leader, struct fildedesc) tuples. 96 * Each process has a pointer to such a structure when detailed tracking 97 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor 98 * table to be shared by processes having different "p_leader" pointers 99 * and thus distinct POSIX style locks. 100 */ 101 struct filedesc_to_leader { 102 int fdl_refcount; /* references from struct proc */ 103 int fdl_holdcount; /* temporary hold during closef */ 104 int fdl_wakeup; /* fdfree() waits on closef() */ 105 struct proc *fdl_leader; /* owner of POSIX locks */ 106 /* Circular list */ 107 struct filedesc_to_leader *fdl_prev; 108 struct filedesc_to_leader *fdl_next; 109 }; 110 111 /* 112 * Per-process open flags. 113 */ 114 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 115 #if 0 116 #define UF_MAPPED 0x02 /* mapped from device */ 117 #endif 118 119 /* 120 * This structure that holds the information needed to send a SIGIO or 121 * a SIGURG signal to a process or process group when new data arrives 122 * on a device or socket. The structure is placed on an SLIST belonging 123 * to the proc or pgrp so that the entire list may be revoked when the 124 * process exits or the process group disappears. 125 */ 126 struct sigio { 127 union { 128 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */ 129 struct pgrp *siu_pgrp; /* process group to receive ... */ 130 } sio_u; 131 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */ 132 struct sigio **sio_myref; /* location of the pointer that holds 133 * the reference to this structure */ 134 struct ucred *sio_ucred; /* current credentials */ 135 uid_t sio_ruid; /* real user id */ 136 pid_t sio_pgid; /* pgid for signals */ 137 }; 138 #define sio_proc sio_u.siu_proc 139 #define sio_pgrp sio_u.siu_pgrp 140 141 SLIST_HEAD(sigiolst, sigio); 142 143 #ifdef _KERNEL 144 145 struct thread; 146 struct proc; 147 148 /* 149 * Kernel global variables and routines. 150 */ 151 int dupfdopen (struct filedesc *, int, int, int, int); 152 int fdalloc (struct proc *p, int want, int *result); 153 int fdavail (struct proc *p, int n); 154 void fdreserve (struct filedesc *fdp, int fd0, int incr); 155 int falloc (struct proc *p, struct file **resultfp, int *resultfd); 156 int fsetfd (struct proc *p, struct file *fp, int *resultfd); 157 void funsetfd (struct filedesc *fdp, int fd); 158 void fsetcred (struct file *fp, struct ucred *cr); 159 void ffree (struct file *); 160 struct filedesc *fdinit (struct proc *p); 161 struct filedesc *fdshare (struct proc *p); 162 struct filedesc *fdcopy (struct proc *p); 163 void fdfree (struct proc *p); 164 int closef (struct file *fp, struct thread *td); 165 void fdcloseexec (struct proc *p); 166 int fdcheckstd (struct proc *p); 167 struct file *holdfp (struct filedesc *fdp, int fd, int flag); 168 int getvnode (struct filedesc *fdp, int fd, struct file **fpp); 169 int fdissequential (struct file *); 170 void fdsequential (struct file *, int); 171 pid_t fgetown (struct sigio *); 172 int fsetown (pid_t, struct sigio **); 173 void funsetown (struct sigio *); 174 void funsetownlst (struct sigiolst *); 175 void setugidsafety (struct proc *p); 176 177 struct filedesc_to_leader * 178 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 179 struct proc *leader); 180 181 #endif 182 183 #endif 184