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 1.8 2004/11/12 00:09:27 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 struct namecache; 62 63 struct filedesc { 64 struct file **fd_ofiles; /* file structures for open files */ 65 char *fd_ofileflags; /* per-process open file flags */ 66 struct vnode *fd_cdir; /* current directory (phaseout) */ 67 struct vnode *fd_rdir; /* root directory (phaseout) */ 68 struct vnode *fd_jdir; /* jail root directory (phaseout) */ 69 struct namecache *fd_ncdir; /* current directory */ 70 struct namecache *fd_nrdir; /* root directory */ 71 struct namecache *fd_njdir; /* jail directory */ 72 int fd_nfiles; /* number of open files allocated */ 73 u_short fd_lastfile; /* high-water mark of fd_ofiles */ 74 u_short fd_freefile; /* approx. next free file */ 75 u_short fd_cmask; /* mask for file creation */ 76 u_short fd_refcnt; /* reference count */ 77 78 int fd_knlistsize; /* size of knlist */ 79 struct klist *fd_knlist; /* list of attached knotes */ 80 u_long fd_knhashmask; /* size of knhash */ 81 struct klist *fd_knhash; /* hash table for attached knotes */ 82 int fd_holdleaderscount; /* block fdfree() for shared close() */ 83 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 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 }; 99 100 101 102 /* 103 * Structure to keep track of (process leader, struct fildedesc) tuples. 104 * Each process has a pointer to such a structure when detailed tracking 105 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor 106 * table to be shared by processes having different "p_leader" pointers 107 * and thus distinct POSIX style locks. 108 */ 109 struct filedesc_to_leader { 110 int fdl_refcount; /* references from struct proc */ 111 int fdl_holdcount; /* temporary hold during closef */ 112 int fdl_wakeup; /* fdfree() waits on closef() */ 113 struct proc *fdl_leader; /* owner of POSIX locks */ 114 /* Circular list */ 115 struct filedesc_to_leader *fdl_prev; 116 struct filedesc_to_leader *fdl_next; 117 }; 118 119 /* 120 * Per-process open flags. 121 */ 122 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 123 #if 0 124 #define UF_MAPPED 0x02 /* mapped from device */ 125 #endif 126 127 /* 128 * Storage required per open file descriptor. 129 */ 130 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 131 132 /* 133 * This structure that holds the information needed to send a SIGIO or 134 * a SIGURG signal to a process or process group when new data arrives 135 * on a device or socket. The structure is placed on an SLIST belonging 136 * to the proc or pgrp so that the entire list may be revoked when the 137 * process exits or the process group disappears. 138 */ 139 struct sigio { 140 union { 141 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */ 142 struct pgrp *siu_pgrp; /* process group to receive ... */ 143 } sio_u; 144 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */ 145 struct sigio **sio_myref; /* location of the pointer that holds 146 * the reference to this structure */ 147 struct ucred *sio_ucred; /* current credentials */ 148 uid_t sio_ruid; /* real user id */ 149 pid_t sio_pgid; /* pgid for signals */ 150 }; 151 #define sio_proc sio_u.siu_proc 152 #define sio_pgrp sio_u.siu_pgrp 153 154 SLIST_HEAD(sigiolst, sigio); 155 156 #ifdef _KERNEL 157 158 struct thread; 159 struct proc; 160 161 /* 162 * Kernel global variables and routines. 163 */ 164 int dupfdopen (struct filedesc *, int, int, int, int); 165 int fdalloc (struct proc *p, int want, int *result); 166 int fdavail (struct proc *p, int n); 167 int falloc (struct proc *p, struct file **resultfp, int *resultfd); 168 int fsetfd (struct proc *p, struct file *fp, int *resultfd); 169 void fsetcred (struct file *fp, struct ucred *cr); 170 void ffree (struct file *); 171 struct filedesc *fdinit (struct proc *p); 172 struct filedesc *fdshare (struct proc *p); 173 struct filedesc *fdcopy (struct proc *p); 174 void fdfree (struct proc *p); 175 int closef (struct file *fp, struct thread *td); 176 void fdcloseexec (struct proc *p); 177 int fdcheckstd (struct proc *p); 178 struct file *holdfp (struct filedesc *fdp, int fd, int flag); 179 int getvnode (struct filedesc *fdp, int fd, struct file **fpp); 180 int fdissequential (struct file *); 181 void fdsequential (struct file *, int); 182 pid_t fgetown (struct sigio *); 183 int fsetown (pid_t, struct sigio **); 184 void funsetown (struct sigio *); 185 void funsetownlst (struct sigiolst *); 186 void setugidsafety (struct proc *p); 187 188 struct filedesc_to_leader * 189 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 190 struct proc *leader); 191 192 #endif 193 194 #endif 195