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/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)filedesc.h 8.1 (Berkeley) 6/2/93
* $FreeBSD$
*/
#ifndef _SYS_FILEDESC_H_
#define _SYS_FILEDESC_H_
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/queue.h>
/*
* This structure is used for the management of descriptors. It may be
* shared by multiple processes.
*
* A process is initially started out with NDFILE descriptors stored within
* this structure, selected to be enough for typical applications based on
* the historical limit of 20 open files (and the usage of descriptors by
* shells). If these descriptors are exhausted, a larger descriptor table
* may be allocated, up to a process' resource limit; the internal arrays
* are then unused. The initial expansion is set to NDEXTENT; each time
* it runs out, it is doubled until the resource limit is reached. NDEXTENT
* should be selected to be the biggest multiple of OFILESIZE (see below)
* that will fit in a power-of-two sized piece of memory.
*/
#define NDFILE 20
#define NDEXTENT 50 /* 250 bytes in 256-byte alloc. */
struct filedesc {
struct file **fd_ofiles; /* file structures for open files */
char *fd_ofileflags; /* per-process open file flags */
struct vnode *fd_cdir; /* current directory */
struct vnode *fd_rdir; /* root directory */
struct vnode *fd_jdir; /* jail root directory */
int fd_nfiles; /* number of open files allocated */
int fd_lastfile; /* high-water mark of fd_ofiles */
int fd_freefile; /* approx. next free file */
u_short fd_cmask; /* mask for file creation */
u_short fd_refcnt; /* reference count */
int fd_knlistsize; /* size of knlist */
struct klist *fd_knlist; /* list of attached knotes */
u_long fd_knhashmask; /* size of knhash */
struct klist *fd_knhash; /* hash table for attached knotes */
struct mtx fd_mtx; /* mtx to protect the members of struct filedesc */
};
/*
* Basic allocation of descriptors:
* one of the above, plus arrays for NDFILE descriptors.
*/
struct filedesc0 {
struct filedesc fd_fd;
/*
* These arrays are used when the number of open files is
* <= NDFILE, and are then pointed to by the pointers above.
*/
struct file *fd_dfiles[NDFILE];
char fd_dfileflags[NDFILE];
};
/*
* Per-process open flags.
*/
#define UF_EXCLOSE 0x01 /* auto-close on exec */
#if 0
#define UF_MAPPED 0x02 /* mapped from device */
#endif
/*
* Storage required per open file descriptor.
*/
#define OFILESIZE (sizeof(struct file *) + sizeof(char))
/*
* This structure holds the information needed to send a SIGIO or
* a SIGURG signal to a process or process group when new data arrives
* on a device or socket. The structure is placed on an SLIST belonging
* to the proc or pgrp so that the entire list may be revoked when the
* process exits or the process group disappears.
*
* (c) const
* (pg) locked by either the process or process group lock
*/
struct sigio {
union {
struct proc *siu_proc; /* (c) process to receive SIGIO/SIGURG */
struct pgrp *siu_pgrp; /* (c) process group to receive ... */
} sio_u;
SLIST_ENTRY(sigio) sio_pgsigio; /* (pg) sigio's for process or group */
struct sigio **sio_myref; /* (c) location of the pointer that holds
* the reference to this structure */
struct ucred *sio_ucred; /* (c) current credentials */
pid_t sio_pgid; /* (c) pgid for signals */
};
#define sio_proc sio_u.siu_proc
#define sio_pgrp sio_u.siu_pgrp
SLIST_HEAD(sigiolst, sigio);
#ifdef _KERNEL
#define FILEDESC_LOCK_DESC "filedesc structure"
/* Lock a file descriptor table. */
#define FILEDESC_LOCK(fd) mtx_lock(&(fd)->fd_mtx)
#define FILEDESC_UNLOCK(fd) mtx_unlock(&(fd)->fd_mtx)
#define FILEDESC_LOCKED(fd) mtx_owned(&(fd)->fd_mtx)
#define FILEDESC_LOCK_ASSERT(fd, type) mtx_assert(&(fd)->fd_mtx, (type))
int closef(struct file *fp, struct thread *p);
int dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd,
int mode, int error);
int falloc(struct thread *p, struct file **resultfp, int *resultfd);
int fdalloc(struct thread *p, int want, int *result);
int fdavail(struct thread *td, int n);
void fdcloseexec(struct thread *td);
int fdcheckstd(struct thread *td);
struct filedesc *fdcopy(struct thread *td);
void fdfree(struct thread *td);
struct filedesc *fdinit(struct thread *td);
struct filedesc *fdshare(struct proc *p);
void ffree(struct file *fp);
static __inline struct file * fget_locked(struct filedesc *fdp, int fd);
pid_t fgetown(struct sigio *sigio);
int fsetown(pid_t pgid, struct sigio **sigiop);
void funsetown(struct sigio *sigio);
void funsetownlst(struct sigiolst *sigiolst);
int getvnode(struct filedesc *fdp, int fd, struct file **fpp);
void setugidsafety(struct thread *td);
static __inline struct file *
fget_locked(fdp, fd)
struct filedesc *fdp;
int fd;
{
/* u_int cast checks for negative descriptors. */
return ((u_int)fd >= fdp->fd_nfiles ? NULL : fdp->fd_ofiles[fd]);
}
#endif /* _KERNEL */
#endif /* !_SYS_FILEDESC_H_ */
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