/*-
 * Copyright (c) 1982, 1986, 1989, 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.
 * 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.
 *
 *	@(#)file.h	8.3 (Berkeley) 1/9/95
 * $FreeBSD: src/sys/sys/file.h,v 1.72 2006/05/16 07:50:54 ps Exp $
 */

#ifndef _SYS_FILE_H_
#define	_SYS_FILE_H_

#ifndef _KERNEL
#include <sys/types.h> /* XXX */
#include <sys/fcntl.h>
#include <sys/unistd.h>
#else
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>

struct stat;
struct thread;
struct uio;
struct knote;
struct vnode;
struct socket;


#endif /* _KERNEL */

#define	DTYPE_VNODE	1	/* file */
#define	DTYPE_SOCKET	2	/* communications endpoint */
#define	DTYPE_PIPE	3	/* pipe */
#define	DTYPE_FIFO	4	/* fifo (named pipe) */
#define	DTYPE_KQUEUE	5	/* event queue */
#define	DTYPE_CRYPTO	6	/* crypto */
#define	DTYPE_MQUEUE	7	/* posix message queue */

#ifdef _KERNEL

struct file;
struct ucred;

typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
		    struct ucred *active_cred, int flags,
		    struct thread *td);
#define	FOF_OFFSET	1	/* Use the offset in uio argument */
typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
		    struct ucred *active_cred, struct thread *td);
typedef	int fo_poll_t(struct file *fp, int events,
		    struct ucred *active_cred, struct thread *td);
typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
typedef	int fo_stat_t(struct file *fp, struct stat *sb,
		    struct ucred *active_cred, struct thread *td);
typedef	int fo_close_t(struct file *fp, struct thread *td);
typedef	int fo_flags_t;

struct fileops {
	fo_rdwr_t	*fo_read;
	fo_rdwr_t	*fo_write;
	fo_ioctl_t	*fo_ioctl;
	fo_poll_t	*fo_poll;
	fo_kqfilter_t	*fo_kqfilter;
	fo_stat_t	*fo_stat;
	fo_close_t	*fo_close;
	fo_flags_t	fo_flags;	/* DFLAG_* below */
};

#define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
#define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */

/*
 * Kernel descriptor table.
 * One entry for each open kernel vnode and socket.
 *
 * Below is the list of locks that protects members in struct file.
 *
 * (fl)	filelist_lock
 * (f)	f_mtx in struct file
 * none	not locked
 */

struct file {
	LIST_ENTRY(file) f_list;/* (fl) list of active files */
	short	f_type;		/* descriptor type */
	void	*f_data;	/* file descriptor specific data */
	u_int	f_flag;		/* see fcntl.h */
	struct mtx	*f_mtxp;	/* mutex to protect data */
	struct fileops *f_ops;	/* File operations */
	struct	ucred *f_cred;	/* credentials associated with descriptor */
	int	f_count;	/* (f) reference count */
	struct vnode *f_vnode;	/* NULL or applicable vnode */

	/* DFLAG_SEEKABLE specific fields */
	off_t	f_offset;
	short     f_vnread_flags; /* 
				   * (f) home grown sleep lock for f_offset
				   * Used only for shared vnode locking in
				   * vnread()
				   */
#define  FOFFSET_LOCKED       0x1
#define  FOFFSET_LOCK_WAITING 0x2		 
	/* DTYPE_SOCKET specific fields */
	short	f_gcflag;	/* used by thread doing fd garbage collection */
#define	FMARK		0x1	/* mark during gc() */
#define	FDEFER		0x2	/* defer for next gc pass */
	int	f_msgcount;	/* (f) references from message queue */

	/* DTYPE_VNODE specific fields */
	int	f_seqcount;	/*
				 * count of sequential accesses -- cleared
				 * by most seek operations.
				 */
	off_t	f_nextoff;	/*
				 * offset of next expected read or write
				 */
	void	*f_label;	/* Place-holder for struct label pointer. */
};

#endif /* _KERNEL */

/*
 * Userland version of struct file, for sysctl
 */
struct xfile {
	size_t	xf_size;	/* size of struct xfile */
	pid_t	xf_pid;		/* owning process */
	uid_t	xf_uid;		/* effective uid of owning process */
	int	xf_fd;		/* descriptor number */
	void	*xf_file;	/* address of struct file */
	short	xf_type;	/* descriptor type */
	int	xf_count;	/* reference count */
	int	xf_msgcount;	/* references from message queue */
	off_t	xf_offset;	/* file offset */
	void	*xf_data;	/* file descriptor specific data */
	void	*xf_vnode;	/* vnode pointer */
	u_int	xf_flag;	/* flags (see fcntl.h) */
};

#ifdef _KERNEL

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_FILE);
#endif

LIST_HEAD(filelist, file);
extern struct filelist filehead; /* (fl) head of list of open files */
extern struct fileops vnops;
extern struct fileops badfileops;
extern struct fileops socketops;
extern int maxfiles;		/* kernel limit on number of open files */
extern int maxfilesperproc;	/* per process limit on number of open files */
extern int openfiles;		/* (fl) actual number of open files */
extern struct sx filelist_lock; /* sx to protect filelist and openfiles */

int fget(struct thread *td, int fd, struct file **fpp);
int fget_read(struct thread *td, int fd, struct file **fpp);
int fget_write(struct thread *td, int fd, struct file **fpp);
int fdrop(struct file *fp, struct thread *td);

/*
 * The socket operations are used a couple of places.
 * XXX: This is wrong, they should go through the operations vector for
 * XXX: sockets instead of going directly for the individual functions. /phk
 */
fo_rdwr_t	soo_read;
fo_rdwr_t	soo_write;
fo_ioctl_t	soo_ioctl;
fo_poll_t	soo_poll;
fo_kqfilter_t	soo_kqfilter;
fo_stat_t	soo_stat;
fo_close_t	soo_close;

/* Lock a file. */
#define	FILE_LOCK(f)	mtx_lock((f)->f_mtxp)
#define	FILE_UNLOCK(f)	mtx_unlock((f)->f_mtxp)
#define	FILE_LOCKED(f)	mtx_owned((f)->f_mtxp)
#define	FILE_LOCK_ASSERT(f, type) mtx_assert((f)->f_mtxp, (type))

int fgetvp(struct thread *td, int fd, struct vnode **vpp);
int fgetvp_read(struct thread *td, int fd, struct vnode **vpp);
int fgetvp_write(struct thread *td, int fd, struct vnode **vpp);

int fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp);
void fputsock(struct socket *sp);

#define	fhold_locked(fp)						\
	do {								\
		FILE_LOCK_ASSERT(fp, MA_OWNED);				\
		(fp)->f_count++;					\
	} while (0)

#define	fhold(fp)							\
	do {								\
		FILE_LOCK(fp);						\
		(fp)->f_count++;					\
		FILE_UNLOCK(fp);					\
	} while (0)

static __inline fo_rdwr_t	fo_read;
static __inline fo_rdwr_t	fo_write;
static __inline fo_ioctl_t	fo_ioctl;
static __inline fo_poll_t	fo_poll;
static __inline fo_kqfilter_t	fo_kqfilter;
static __inline fo_stat_t	fo_stat;
static __inline fo_close_t	fo_close;

static __inline int
fo_read(fp, uio, active_cred, flags, td)
	struct file *fp;
	struct uio *uio;
	struct ucred *active_cred;
	int flags;
	struct thread *td;
{

	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
}

static __inline int
fo_write(fp, uio, active_cred, flags, td)
	struct file *fp;
	struct uio *uio;
	struct ucred *active_cred;
	int flags;
	struct thread *td;
{

	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
}

static __inline int
fo_ioctl(fp, com, data, active_cred, td)
	struct file *fp;
	u_long com;
	void *data;
	struct ucred *active_cred;
	struct thread *td;
{

	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
}

static __inline int
fo_poll(fp, events, active_cred, td)
	struct file *fp;
	int events;
	struct ucred *active_cred;
	struct thread *td;
{

	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
}

static __inline int
fo_stat(fp, sb, active_cred, td)
	struct file *fp;
	struct stat *sb;
	struct ucred *active_cred;
	struct thread *td;
{

	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred, td));
}

static __inline int
fo_close(fp, td)
	struct file *fp;
	struct thread *td;
{

	return ((*fp->f_ops->fo_close)(fp, td));
}

static __inline int
fo_kqfilter(fp, kn)
	struct file *fp;
	struct knote *kn;
{

	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
}

#endif /* _KERNEL */

#endif /* !SYS_FILE_H */
