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 */ 32 33 #ifndef _SYS_FILEDESC_H_ 34 #define _SYS_FILEDESC_H_ 35 36 #ifndef _SYS_TYPES_H_ 37 #include <sys/types.h> 38 #endif 39 #ifndef _SYS_QUEUE_H_ 40 #include <sys/queue.h> 41 #endif 42 #ifndef _SYS_SPINLOCK_H_ 43 #include <sys/spinlock.h> 44 #endif 45 #ifndef _SYS_NAMECACHE_H_ 46 #include <sys/namecache.h> 47 #endif 48 49 /* 50 * This structure is used for the management of descriptors. It may be 51 * shared by multiple processes. 52 * 53 * A process is initially started out with NDFILE descriptors stored within 54 * this structure, selected to be enough for typical applications based on 55 * the historical limit of 20 open files (and the usage of descriptors by 56 * shells) and the constraint of being one less than a power of 2. 57 * If these descriptors are exhausted, a larger descriptor table 58 * may be allocated, up to a process' resource limit; the internal arrays 59 * are then unused. Each time the file table runs out, it is doubled until 60 * the resource limit is reached. 61 */ 62 #define NDFILE 15 /* must be of the form 2^n - 1 */ 63 #define NTDCACHEFD 4 /* max td's caching same fd */ 64 65 struct file; 66 struct klist; 67 struct fdcache; 68 69 struct fdnode { 70 struct file *fp; 71 char fileflags; 72 char isfull; 73 char iterator; 74 char reserved; /* descriptor has been reserved */ 75 int allocated; /* subtree allocation count */ 76 struct fdcache *tdcache[NTDCACHEFD]; 77 }; 78 79 struct filedesc { 80 struct fdnode *fd_files; /* file structures for open files */ 81 struct vnode *fd_cdir; /* current directory (phaseout) */ 82 struct vnode *fd_rdir; /* root directory (phaseout) */ 83 struct vnode *fd_jdir; /* jail root directory (phaseout) */ 84 struct nchandle fd_ncdir; /* current directory */ 85 struct nchandle fd_nrdir; /* root directory */ 86 struct nchandle fd_njdir; /* jail directory */ 87 int fd_nfiles; /* number of open files allocated */ 88 int fd_lastfile; /* high-water mark of fd_files */ 89 int fd_freefile; /* approx. next free file */ 90 int fd_cmask; /* mask for file creation */ 91 int fd_refcnt; /* reference count */ 92 int fd_softrefs; /* softrefs to prevent destruction */ 93 int fd_holdleaderscount; /* block fdfree() for shared close() */ 94 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 95 int fd_closedcounter; /* detect close() */ 96 struct spinlock fd_spin; 97 struct fdnode fd_builtin_files[NDFILE]; 98 }; 99 100 /* 101 * Structure to keep track of (process leader, struct fildedesc) tuples. 102 * Each process has a pointer to such a structure when detailed tracking 103 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor 104 * table to be shared by processes having different "p_leader" pointers 105 * and thus distinct POSIX style locks. 106 */ 107 struct filedesc_to_leader { 108 int fdl_refcount; /* references from struct proc */ 109 int fdl_holdcount; /* temporary hold during closef */ 110 int fdl_wakeup; /* fdfree() waits on closef() */ 111 struct proc *fdl_leader; /* owner of POSIX locks */ 112 /* Circular list */ 113 struct filedesc_to_leader *fdl_prev; 114 struct filedesc_to_leader *fdl_next; 115 }; 116 117 /* 118 * Per-process open flags. 119 */ 120 #define UF_EXCLOSE 0x01 /* auto-close on exec */ 121 122 /* 123 * This structure that holds the information needed to send a SIGIO or 124 * a SIGURG signal to a process or process group when new data arrives 125 * on a device or socket. The structure is placed on an SLIST belonging 126 * to the proc or pgrp so that the entire list may be revoked when the 127 * process exits or the process group disappears. 128 */ 129 struct sigio { 130 union { 131 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */ 132 struct pgrp *siu_pgrp; /* process group to receive ... */ 133 } sio_u; 134 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */ 135 struct sigio **sio_myref; /* location of the pointer that holds */ 136 struct ucred *sio_ucred; /* current credentials */ 137 uid_t sio_ruid; /* real user id */ 138 pid_t sio_pgid; /* pgid for signals */ 139 }; 140 #define sio_proc sio_u.siu_proc 141 #define sio_pgrp sio_u.siu_pgrp 142 143 SLIST_HEAD(sigiolst, sigio); 144 145 #ifdef _KERNEL 146 147 /* Type flags for kern_dup(). */ 148 #define DUP_FIXED 0x1 /* Copy to specific fd even if in use */ 149 #define DUP_VARIABLE 0x2 /* Copy fd to an unused fd */ 150 #define DUP_CLOEXEC 0x4 /* Set fd close on exec flag */ 151 #define DUP_FCNTL 0x8 /* Set for F_DUPFD and F_DUPFD_CLOEXEC */ 152 153 struct thread; 154 struct proc; 155 struct lwp; 156 157 /* 158 * Kernel global variables and routines. 159 */ 160 int fdalloc (struct proc *p, int want, int *result); 161 int fdavail (struct proc *p, int n); 162 int falloc (struct lwp *lp, struct file **resultfp, int *resultfd); 163 void fsetfd (struct filedesc *fdp, struct file *fp, int fd); 164 int fgetfdflags(struct filedesc *fdp, int fd, int *flagsp); 165 int fsetfdflags(struct filedesc *fdp, int fd, int add_flags); 166 int fclrfdflags(struct filedesc *fdp, int fd, int rem_flags); 167 void fsetcred (struct file *fp, struct ucred *cr); 168 void fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask); 169 struct filedesc *fdinit (struct proc *p); 170 struct filedesc *fdshare (struct proc *p); 171 int fdcopy (struct proc *p, struct filedesc **fpp); 172 void fdfree (struct proc *p, struct filedesc *repl); 173 int fdrevoke(void *f_data, short f_type, struct ucred *cred); 174 int closef (struct file *fp, struct proc *p); 175 void fdcloseexec (struct proc *p); 176 int fdcheckstd (struct lwp *lp); 177 struct file *holdfp (struct thread *td, int fd, int flag); 178 struct file *holdfp_fdp (struct filedesc *fdp, int fd, int flag); 179 struct file *holdfp_fdp_locked (struct filedesc *fdp, int fd, int flag); 180 int holdsock (struct thread *td, int fdes, struct file **fpp); 181 int holdvnode (struct thread *td, int fd, struct file **fpp); 182 int holdvnode2 (struct thread *td, int fd, struct file **fpp, 183 char *fflagsp); 184 void dropfp(struct thread *td, int fd, struct file *fp); 185 int fdissequential (struct file *); 186 void fdsequential (struct file *, int); 187 pid_t fgetown (struct sigio **); 188 int fsetown (pid_t, struct sigio **); 189 void funsetown (struct sigio **); 190 void funsetownlst (struct sigiolst *); 191 void setugidsafety (struct proc *p); 192 void allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data); 193 void fexitcache(struct thread *td); 194 195 struct filedesc_to_leader * 196 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 197 struct proc *leader); 198 199 #endif 200 201 #endif 202