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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 30 * $FreeBSD: src/sys/sys/filedesc.h,v 1.19.2.5 2003/06/06 20:21:32 tegge Exp $ 31 * $DragonFly: src/sys/sys/filedesc.h,v 1.20 2006/10/27 04:56:33 dillon Exp $ 32 */ 33 34 #ifndef _SYS_FILEDESC_H_ 35 #define _SYS_FILEDESC_H_ 36 37 #ifndef _SYS_TYPES_H_ 38 #include <sys/types.h> 39 #endif 40 #ifndef _SYS_QUEUE_H_ 41 #include <sys/queue.h> 42 #endif 43 #ifndef _SYS_SPINLOCK_H_ 44 #include <sys/spinlock.h> 45 #endif 46 #ifndef _SYS_NAMECACHE_H_ 47 #include <sys/namecache.h> 48 #endif 49 50 /* 51 * This structure is used for the management of descriptors. It may be 52 * shared by multiple processes. 53 * 54 * A process is initially started out with NDFILE descriptors stored within 55 * this structure, selected to be enough for typical applications based on 56 * the historical limit of 20 open files (and the usage of descriptors by 57 * shells) and the constraint of being one less than a power of 2. 58 * If these descriptors are exhausted, a larger descriptor table 59 * may be allocated, up to a process' resource limit; the internal arrays 60 * are then unused. Each time the file table runs out, it is doubled until 61 * the resource limit is reached. 62 */ 63 #define NDFILE 15 /* must be of the form 2^n - 1 */ 64 #define NTDCACHEFD 4 /* max td's caching same fd */ 65 66 struct file; 67 struct klist; 68 struct fdcache; 69 70 struct fdnode { 71 struct file *fp; 72 char fileflags; 73 char isfull; 74 char iterator; 75 char reserved; /* descriptor has been reserved */ 76 int allocated; /* subtree allocation count */ 77 struct fdcache *tdcache[NTDCACHEFD]; 78 }; 79 80 struct filedesc { 81 struct fdnode *fd_files; /* file structures for open files */ 82 struct vnode *fd_cdir; /* current directory (phaseout) */ 83 struct vnode *fd_rdir; /* root directory (phaseout) */ 84 struct vnode *fd_jdir; /* jail root directory (phaseout) */ 85 struct nchandle fd_ncdir; /* current directory */ 86 struct nchandle fd_nrdir; /* root directory */ 87 struct nchandle fd_njdir; /* jail directory */ 88 int fd_nfiles; /* number of open files allocated */ 89 int fd_lastfile; /* high-water mark of fd_files */ 90 int fd_freefile; /* approx. next free file */ 91 int fd_cmask; /* mask for file creation */ 92 int fd_refcnt; /* reference count */ 93 int fd_softrefs; /* softrefs to prevent destruction */ 94 int fd_holdleaderscount; /* block fdfree() for shared close() */ 95 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 96 int fd_closedcounter; /* detect close() */ 97 struct spinlock fd_spin; 98 struct fdnode fd_builtin_files[NDFILE]; 99 }; 100 101 /* 102 * Structure to keep track of (process leader, struct fildedesc) tuples. 103 * Each process has a pointer to such a structure when detailed tracking 104 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor 105 * table to be shared by processes having different "p_leader" pointers 106 * and thus distinct POSIX style locks. 107 */ 108 struct filedesc_to_leader { 109 int fdl_refcount; /* references from struct proc */ 110 int fdl_holdcount; /* temporary hold during closef */ 111 int fdl_wakeup; /* fdfree() waits on closef() */ 112 struct proc *fdl_leader; /* owner of POSIX locks */ 113 /* Circular list */ 114 struct filedesc_to_leader *fdl_prev; 115 struct filedesc_to_leader *fdl_next; 116 }; 117 118 /* 119 * Per-process open flags. 120 */ 121 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 122 123 /* 124 * This structure that holds the information needed to send a SIGIO or 125 * a SIGURG signal to a process or process group when new data arrives 126 * on a device or socket. The structure is placed on an SLIST belonging 127 * to the proc or pgrp so that the entire list may be revoked when the 128 * process exits or the process group disappears. 129 */ 130 struct sigio { 131 union { 132 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */ 133 struct pgrp *siu_pgrp; /* process group to receive ... */ 134 } sio_u; 135 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */ 136 struct sigio **sio_myref; /* location of the pointer that holds */ 137 struct ucred *sio_ucred; /* current credentials */ 138 uid_t sio_ruid; /* real user id */ 139 pid_t sio_pgid; /* pgid for signals */ 140 }; 141 #define sio_proc sio_u.siu_proc 142 #define sio_pgrp sio_u.siu_pgrp 143 144 SLIST_HEAD(sigiolst, sigio); 145 146 #ifdef _KERNEL 147 148 struct thread; 149 struct proc; 150 struct lwp; 151 152 /* 153 * Kernel global variables and routines. 154 */ 155 int dupfdopen (struct thread *, int, int, int, int); 156 int fdalloc (struct proc *p, int want, int *result); 157 int fdavail (struct proc *p, int n); 158 int falloc (struct lwp *lp, struct file **resultfp, int *resultfd); 159 void fsetfd (struct filedesc *fdp, struct file *fp, int fd); 160 int fgetfdflags(struct filedesc *fdp, int fd, int *flagsp); 161 int fsetfdflags(struct filedesc *fdp, int fd, int add_flags); 162 int fclrfdflags(struct filedesc *fdp, int fd, int rem_flags); 163 void fsetcred (struct file *fp, struct ucred *cr); 164 void fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask); 165 struct filedesc *fdinit (struct proc *p); 166 struct filedesc *fdshare (struct proc *p); 167 int fdcopy (struct proc *p, struct filedesc **fpp); 168 void fdfree (struct proc *p, struct filedesc *repl); 169 int fdrevoke(void *f_data, short f_type, struct ucred *cred); 170 int closef (struct file *fp, struct proc *p); 171 void fdcloseexec (struct proc *p); 172 int fdcheckstd (struct lwp *lp); 173 struct file *holdfp (struct thread *td, int fd, int flag); 174 struct file *holdfp_fdp (struct filedesc *fdp, int fd, int flag); 175 struct file *holdfp_fdp_locked (struct filedesc *fdp, int fd, int flag); 176 int holdsock (struct thread *td, int fdes, struct file **fpp); 177 int holdvnode (struct thread *td, int fd, struct file **fpp); 178 void dropfp(struct thread *td, int fd, struct file *fp); 179 int fdissequential (struct file *); 180 void fdsequential (struct file *, int); 181 pid_t fgetown (struct sigio **); 182 int fsetown (pid_t, struct sigio **); 183 void funsetown (struct sigio **); 184 void funsetownlst (struct sigiolst *); 185 void setugidsafety (struct proc *p); 186 void allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data); 187 void fexitcache(struct thread *td); 188 189 struct filedesc_to_leader * 190 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 191 struct proc *leader); 192 193 #endif 194 195 #endif 196