xnu-1228.9.59.tar.gz

[apple/xnu.git] / bsd / kern / kern_descrip.c

/*
 * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1982, 1986, 1989, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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.
 *
 *	@(#)kern_descrip.c	8.8 (Berkeley) 2/14/95
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/vnode_internal.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/file_internal.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/syslog.h>
#include <sys/unistd.h>
#include <sys/resourcevar.h>
#include <sys/aio_kern.h>
#include <sys/ev.h>
#include <kern/lock.h>

#include <bsm/audit_kernel.h>

#include <sys/mount_internal.h>
#include <sys/kdebug.h>
#include <sys/sysproto.h>
#include <sys/pipe.h>
#include <kern/kern_types.h>
#include <kern/kalloc.h>
#include <libkern/OSAtomic.h>

#include <sys/ubc_internal.h>

struct psemnode;
struct pshmnode;

int fdopen(dev_t dev, int mode, int type, proc_t p);
int finishdup(proc_t p, struct filedesc *fdp, int old, int new, register_t *retval);

int falloc_locked(proc_t p, struct fileproc **resultfp, int *resultfd, vfs_context_t ctx, int locked);
int fdgetf_noref(proc_t p, int fd, struct fileproc **resultfp);
void fg_drop(struct fileproc * fp);
void fg_free(struct fileglob *fg);
void fg_ref(struct fileproc * fp);

/* flags for close_internal_locked */
#define FD_DUP2RESV 1
static int close_internal_locked(struct proc *p, int fd, struct fileproc *fp, int flags);

static int closef_finish(struct fileproc *fp, struct fileglob *fg, proc_t p, vfs_context_t ctx);

/* We don't want these exported */
__private_extern__
int open1(vfs_context_t, struct nameidata *, int, struct vnode_attr *, register_t *);

__private_extern__
int unlink1(vfs_context_t, struct nameidata *, int);

static void _fdrelse(struct proc * p, int fd);


extern void file_lock_init(void) __attribute__((section("__TEXT, initcode")));
extern int kqueue_stat(struct fileproc *fp, void *ub, int isstat4, proc_t p);
#if SOCKETS
extern int soo_stat(struct socket *so, void *ub, int isstat64);
#endif /* SOCKETS */

extern kauth_scope_t	kauth_scope_fileop;

extern int cs_debug;

#define f_flag f_fglob->fg_flag
#define f_type f_fglob->fg_type
#define f_msgcount f_fglob->fg_msgcount
#define f_cred f_fglob->fg_cred
#define f_ops f_fglob->fg_ops
#define f_offset f_fglob->fg_offset
#define f_data f_fglob->fg_data
/*
 * Descriptor management.
 */
struct filelist filehead;	/* head of list of open files */
struct fmsglist fmsghead;	/* head of list of open files */
struct fmsglist fmsg_ithead;	/* head of list of open files */
int nfiles;			/* actual number of open files */


lck_grp_attr_t * file_lck_grp_attr;
lck_grp_t * file_lck_grp;
lck_attr_t * file_lck_attr;

lck_mtx_t * uipc_lock;
lck_mtx_t * file_flist_lock;


/*
 * file_lock_init
 *
 * Description:	Initialize the file lock group and the uipc and flist locks
 *
 * Parameters:	(void)
 *
 * Returns:	void
 *
 * Notes:	Called at system startup from bsd_init().
 */
void
file_lock_init(void)
{
	/* allocate file lock group attribute and group */
	file_lck_grp_attr= lck_grp_attr_alloc_init();

	file_lck_grp = lck_grp_alloc_init("file",  file_lck_grp_attr);

	/* Allocate file lock attribute */
	file_lck_attr = lck_attr_alloc_init();

	uipc_lock = lck_mtx_alloc_init(file_lck_grp, file_lck_attr);
	file_flist_lock = lck_mtx_alloc_init(file_lck_grp, file_lck_attr);
}


/*
 * proc_fdlock, proc_fdlock_spin
 *
 * Description:	Lock to control access to the per process struct fileproc
 *		and struct filedesc
 *
 * Parameters:	p				Process to take the lock on
 *
 * Returns:	void
 *
 * Notes:	The lock is initialized in forkproc() and destroyed in
 *		reap_child_process().
 */
void
proc_fdlock(proc_t p)
{
	lck_mtx_lock(&p->p_fdmlock);
}

void
proc_fdlock_spin(proc_t p)
{
	lck_mtx_lock_spin(&p->p_fdmlock);
}

void
proc_fdlock_assert(proc_t p, int assertflags)
{
	lck_mtx_assert(&p->p_fdmlock, assertflags);
}


/*
 * proc_fdunlock
 *
 * Description:	Unlock the lock previously locked by a call to proc_fdlock()
 *
 * Parameters:	p				Process to drop the lock on
 *
 * Returns:	void
 */
void
proc_fdunlock(proc_t p)
{
	lck_mtx_unlock(&p->p_fdmlock);
}


/*
 * System calls on descriptors.
 */


/*
 * getdtablesize
 *
 * Description:	Returns the per process maximum size of the descriptor table
 *
 * Parameters:	p				Process being queried
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *
 * Implicit returns:
 *		*retval (modified)		Size of dtable
 */
int
getdtablesize(proc_t p, __unused struct getdtablesize_args *uap, register_t *retval)
{
	proc_fdlock_spin(p);
	*retval = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
	proc_fdunlock(p);

	return (0);
}


void
procfdtbl_reservefd(struct proc * p, int fd)
{
	p->p_fd->fd_ofiles[fd] = NULL;
        p->p_fd->fd_ofileflags[fd] |= UF_RESERVED;
}

void
procfdtbl_markclosefd(struct proc * p, int fd)
{
        p->p_fd->fd_ofileflags[fd] |= (UF_RESERVED | UF_CLOSING);
}

void
procfdtbl_releasefd(struct proc * p, int fd, struct fileproc * fp)
{
	if (fp != NULL)
        	p->p_fd->fd_ofiles[fd] = fp;
        p->p_fd->fd_ofileflags[fd] &= ~UF_RESERVED;
	if ((p->p_fd->fd_ofileflags[fd] & UF_RESVWAIT) == UF_RESVWAIT) {
		p->p_fd->fd_ofileflags[fd] &= ~UF_RESVWAIT;
		wakeup(&p->p_fd);
	}
}

void 
procfdtbl_waitfd(struct proc * p, int fd)
{
        p->p_fd->fd_ofileflags[fd] |= UF_RESVWAIT;
	msleep(&p->p_fd, &p->p_fdmlock, PRIBIO, "ftbl_waitfd", NULL);
}


void
procfdtbl_clearfd(struct proc * p, int fd)
{
	int waiting;

	waiting = (p->p_fd->fd_ofileflags[fd] & UF_RESVWAIT);
	p->p_fd->fd_ofiles[fd] = NULL;       
	p->p_fd->fd_ofileflags[fd] = 0;
	if ( waiting == UF_RESVWAIT) {
		wakeup(&p->p_fd);
	}
}

/*
 * _fdrelse
 *
 * Description:	Inline utility function to free an fd in a filedesc
 *
 * Parameters:	fdp				Pointer to filedesc fd lies in
 *		fd				fd to free
 *		reserv				fd should be reserved
 *
 * Returns:	void
 *
 * Locks:	Assumes proc_fdlock for process pointing to fdp is held by
 *		the caller
 */
static void
_fdrelse(struct proc * p, int fd)
{
	struct filedesc *fdp = p->p_fd;
	int nfd = 0;

	if (fd < fdp->fd_freefile)
		fdp->fd_freefile = fd;
#if DIAGNOSTIC
	if (fd > fdp->fd_lastfile)
 		panic("fdrelse: fd_lastfile inconsistent");
#endif
	procfdtbl_clearfd(p, fd);

	while ((nfd = fdp->fd_lastfile) > 0 &&
			fdp->fd_ofiles[nfd] == NULL &&
			!(fdp->fd_ofileflags[nfd] & UF_RESERVED))
		fdp->fd_lastfile--;
}


/*
 * dup
 *
 * Description:	Duplicate a file descriptor.
 *
 * Parameters:	p				Process performing the dup
 *		uap->fd				The fd to dup
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		!0				Errno
 *
 * Implicit returns:
 *		*retval (modified)		The new descriptor
 */
int
dup(proc_t p, struct dup_args *uap, register_t *retval)
{
	struct filedesc *fdp = p->p_fd;
	int old = uap->fd;
	int new, error;
	struct fileproc *fp;

	proc_fdlock(p);
	if ( (error = fp_lookup(p, old, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	if ( (error = fdalloc(p, 0, &new)) ) {
		fp_drop(p, old, fp, 1);
		proc_fdunlock(p);
		return (error);
	}
	error = finishdup(p, fdp, old, new, retval);
	fp_drop(p, old, fp, 1);
	proc_fdunlock(p);

	return (error);
}


/*
 * dup2
 *
 * Description:	Duplicate a file descriptor to a particular value.
 *
 * Parameters:	p				Process performing the dup
 *		uap->fd				The fd to dup
 *		uap->to				The fd to dup it to
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		!0				Errno
 *
 * Implicit returns:
 *		*retval (modified)		The new descriptor
 */
int
dup2(proc_t p, struct dup2_args *uap, register_t *retval)
{
	struct filedesc *fdp = p->p_fd;
	int old = uap->from, new = uap->to;
	int i, error;
	struct fileproc *fp, *nfp;

	proc_fdlock(p);

startover:
	if ( (error = fp_lookup(p, old, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	if (new < 0 ||
		(rlim_t)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
	    new >= maxfiles) {
		fp_drop(p, old, fp, 1);
		proc_fdunlock(p);
		return (EBADF);
	}
	if (old == new) {
		fp_drop(p, old, fp, 1);
		*retval = new;
		proc_fdunlock(p);
		return (0);
	}
	if (new < 0 || new >= fdp->fd_nfiles) {
		if ( (error = fdalloc(p, new, &i)) ) {
			fp_drop(p, old, fp, 1);
			proc_fdunlock(p);
			return (error);
		}
		if (new != i) {
			fdrelse(p, i);
			goto closeit;
		}
	} else {
closeit:
		while ((fdp->fd_ofileflags[new] & UF_RESERVED) == UF_RESERVED)  {
				fp_drop(p, old, fp, 1);
				procfdtbl_waitfd(p, new);
#if DIAGNOSTIC
				proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif
				goto startover;
		}

		if ((fdp->fd_ofiles[new] != NULL)  && ((error = fp_lookup(p, new, &nfp, 1)) == 0)) {
			fp_drop(p, old, fp, 1);
			(void)close_internal_locked(p, new, nfp, FD_DUP2RESV);
#if DIAGNOSTIC
			proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif
			procfdtbl_clearfd(p, new);
			goto startover;
		} else  {
#if DIAGNOSTIC
			if (fdp->fd_ofiles[new] != NULL)
				panic("dup2: unable to get ref on a fileproc %d\n", new);
#endif
			procfdtbl_reservefd(p, new);
		}

#if DIAGNOSTIC
		proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif

	}
#if DIAGNOSTIC
	if (fdp->fd_ofiles[new] != 0)
		panic("dup2-1: overwriting fd_ofiles with new %d\n", new);
	if ((fdp->fd_ofileflags[new] & UF_RESERVED) == 0)
		panic("dup2-1: unreserved  fileflags  with new %d\n", new);
#endif
	error = finishdup(p, fdp, old, new, retval);
	fp_drop(p, old, fp, 1);
	proc_fdunlock(p);

	return(error);
}


/*
 * fcntl
 *
 * Description:	The file control system call.
 *
 * Parameters:	p				Process performing the fcntl
 *		uap->fd				The fd to operate against
 *		uap->cmd			The command to perform
 *		uap->arg			Pointer to the command argument
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		!0				Errno (see fcntl_nocancel)
 *
 * Implicit returns:
 *		*retval (modified)		fcntl return value (if any)
 *
 * Notes:	This system call differs from fcntl_nocancel() in that it
 *		tests for cancellation prior to performing a potentially
 *		blocking operation.
 */
int
fcntl(proc_t p, struct fcntl_args *uap, register_t *retval)
{
	__pthread_testcancel(1);
	return(fcntl_nocancel(p, (struct fcntl_nocancel_args *)uap, retval));
}


/*
 * fcntl_nocancel
 *
 * Description:	A non-cancel-testing file control system call.
 *
 * Parameters:	p				Process performing the fcntl
 *		uap->fd				The fd to operate against
 *		uap->cmd			The command to perform
 *		uap->arg			Pointer to the command argument
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		EINVAL
 *	fp_lookup:EBADF				Bad file descriptor
 * [F_DUPFD]
 *	fdalloc:EMFILE
 *	fdalloc:ENOMEM
 *	finishdup:EBADF
 *	finishdup:ENOMEM
 * [F_SETOWN]
 *		ESRCH
 * [F_SETLK]
 *		EBADF
 *		EOVERFLOW
 *	copyin:EFAULT
 *	vnode_getwithref:???
 *	VNOP_ADVLOCK:???
 * [F_GETLK]
 *		EBADF
 *		EOVERFLOW
 *	copyin:EFAULT
 *	copyout:EFAULT
 *	vnode_getwithref:???
 *	VNOP_ADVLOCK:???
 * [F_PREALLOCATE]
 *		EBADF
 *		EINVAL
 *	copyin:EFAULT
 *	copyout:EFAULT
 *	vnode_getwithref:???
 *	VNOP_ALLOCATE:???
 * [F_SETSIZE,F_RDADVISE]
 *		EBADF
 *	copyin:EFAULT
 *	vnode_getwithref:???
 * [F_RDAHEAD,F_NOCACHE]
 *		EBADF
 *	vnode_getwithref:???
 * [???]
 *
 * Implicit returns:
 *		*retval (modified)		fcntl return value (if any)
 */
int
fcntl_nocancel(proc_t p, struct fcntl_nocancel_args *uap, register_t *retval)
{
	int fd = uap->fd;
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;
	char *pop;
	struct vnode *vp = NULLVP;	/* for AUDIT_ARG() at end */
	int i, tmp, error, error2, flg = F_POSIX;
	struct flock fl;
	struct vfs_context context;
	off_t offset;
	int newmin;
	daddr64_t lbn, bn;
	int devBlockSize = 0;
	unsigned int fflag;
	user_addr_t argp;

	AUDIT_ARG(fd, uap->fd);
	AUDIT_ARG(cmd, uap->cmd);

	proc_fdlock(p);
	if ( (error = fp_lookup(p, fd, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	context.vc_thread = current_thread();
	context.vc_ucred = fp->f_cred;
	if (proc_is64bit(p)) {
		argp = uap->arg;
	}
	else {
		/*
		 * Since the arg parameter is defined as a long but may be
		 * either a long or a pointer we must take care to handle
		 * sign extension issues.  Our sys call munger will sign
		 * extend a long when we are called from a 32-bit process.
		 * Since we can never have an address greater than 32-bits
		 * from a 32-bit process we lop off the top 32-bits to avoid
		 * getting the wrong address
		 */
		argp = CAST_USER_ADDR_T(uap->arg);
	}

	pop = &fdp->fd_ofileflags[fd];

#if CONFIG_MACF
	error = mac_file_check_fcntl(proc_ucred(p), fp->f_fglob, uap->cmd,
	    uap->arg);
	if (error)
		goto out;
#endif

	switch (uap->cmd) {

	case F_DUPFD:
		newmin = CAST_DOWN(int, uap->arg);
		if ((u_int)newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
		    newmin >= maxfiles) {
			error = EINVAL;
			goto out;
		}
		if ( (error = fdalloc(p, newmin, &i)) )
			goto out;
		error = finishdup(p, fdp, fd, i, retval);
		goto out;

	case F_GETFD:
		*retval = (*pop & UF_EXCLOSE)? 1 : 0;
		error = 0;
		goto out;

	case F_SETFD:
		*pop = (*pop &~ UF_EXCLOSE) |
			(uap->arg & 1)? UF_EXCLOSE : 0;
		error = 0;
		goto out;

	case F_GETFL:
		*retval = OFLAGS(fp->f_flag);
		error = 0;
		goto out;

	case F_SETFL:
		fp->f_flag &= ~FCNTLFLAGS;
		tmp = CAST_DOWN(int, uap->arg);
		fp->f_flag |= FFLAGS(tmp) & FCNTLFLAGS;
		tmp = fp->f_flag & FNONBLOCK;
		error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
		if (error)
			goto out;
		tmp = fp->f_flag & FASYNC;
		error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, &context);
		if (!error)
			goto out;
		fp->f_flag &= ~FNONBLOCK;
		tmp = 0;
		(void)fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
		goto out;

	case F_GETOWN:
		if (fp->f_type == DTYPE_SOCKET) {
			*retval = ((struct socket *)fp->f_data)->so_pgid;
			error = 0;
			goto out;
		}
		error = fo_ioctl(fp, (int)TIOCGPGRP, (caddr_t)retval, &context);
		*retval = -*retval;
		goto out;

	case F_SETOWN:
		tmp = CAST_DOWN(pid_t, uap->arg);
		if (fp->f_type == DTYPE_SOCKET) {
			((struct socket *)fp->f_data)->so_pgid = tmp;
			error =0;
			goto out;
		}
		if (fp->f_type == DTYPE_PIPE) {
			error =  fo_ioctl(fp, (int)TIOCSPGRP, (caddr_t)&tmp, &context);
			goto out;
		}

		if (tmp <= 0) {
			tmp = -tmp;
		} else {
			proc_t p1 = proc_find(tmp);
			if (p1 == 0) {
				error = ESRCH;
				goto out;
			}
			tmp = (int)p1->p_pgrpid;
			proc_rele(p1);
		}
		error =  fo_ioctl(fp, (int)TIOCSPGRP, (caddr_t)&tmp, &context);
		goto out;

	case F_SETLKW:
		flg |= F_WAIT;
		/* Fall into F_SETLK */

	case F_SETLK:
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;

		fflag = fp->f_flag;
		offset = fp->f_offset;
		proc_fdunlock(p);

		/* Copy in the lock structure */
		error = copyin(argp, (caddr_t)&fl, sizeof(fl));
		if (error) {
			goto outdrop;
		}

		if ((fl.l_whence == SEEK_CUR) && (fl.l_start + offset < fl.l_start)) {
		    error = EOVERFLOW;
		    goto outdrop;
		}

		if ( (error = vnode_getwithref(vp)) ) {
			goto outdrop;
		}
		if (fl.l_whence == SEEK_CUR)
			fl.l_start += offset;

#if CONFIG_MACF
		error = mac_file_check_lock(proc_ucred(p), fp->f_fglob,
		    F_SETLK, &fl);
		if (error) {
			(void)vnode_put(vp);
			goto outdrop;
		}
#endif
		switch (fl.l_type) {

		case F_RDLCK:
			if ((fflag & FREAD) == 0) {
				(void)vnode_put(vp);
				error = EBADF;
				goto outdrop;
			}
			// XXX UInt32 unsafe for LP64 kernel
			OSBitOrAtomic(P_LADVLOCK, (UInt32 *)&p->p_ladvflag);
			error = VNOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg, &context);
			(void)vnode_put(vp);
			goto outdrop;

		case F_WRLCK:
			if ((fflag & FWRITE) == 0) {
				(void)vnode_put(vp);
				error = EBADF;
				goto outdrop;
			}
			// XXX UInt32 unsafe for LP64 kernel
			OSBitOrAtomic(P_LADVLOCK, (UInt32 *)&p->p_ladvflag);
			error = VNOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg, &context);
			(void)vnode_put(vp);
			goto outdrop;

		case F_UNLCK:
			error = VNOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &fl,
				F_POSIX, &context);
			(void)vnode_put(vp);
			goto outdrop;

		default:
			(void)vnode_put(vp);
			error = EINVAL;
			goto outdrop;
		}

	case F_GETLK:
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;

		offset = fp->f_offset;
		proc_fdunlock(p);

		/* Copy in the lock structure */
		error = copyin(argp, (caddr_t)&fl, sizeof(fl));
		if (error)
			goto outdrop;

		/* Check starting byte and ending byte for EOVERFLOW in SEEK_CUR */
		/* and ending byte for EOVERFLOW in SEEK_SET */
		if (((fl.l_whence == SEEK_CUR) && 
		     ((fl.l_start + offset < fl.l_start) ||
		      ((fl.l_len > 0) && (fl.l_start+offset + fl.l_len - 1 < fl.l_start+offset)))) ||
		    ((fl.l_whence == SEEK_SET) && (fl.l_len > 0) && (fl.l_start + fl.l_len - 1 < fl.l_start)))
		{
			/* lf_advlock doesn't check start/end for F_GETLK if file has no locks */
			error = EOVERFLOW;
			goto outdrop;
		}

		if ((fl.l_whence == SEEK_SET) && (fl.l_start < 0)) {
			error = EINVAL;
			goto outdrop;
		}

		switch (fl.l_type) {
		case F_RDLCK:
		case F_UNLCK:
		case F_WRLCK:
			break;
		default:
			error = EINVAL;
			goto outdrop;
		}

		switch (fl.l_whence) {
		case SEEK_CUR:
		case SEEK_SET:
		case SEEK_END:
			break;
		default:
			error = EINVAL;
			goto outdrop;
		}

		if ( (error = vnode_getwithref(vp)) == 0 ) {
			if (fl.l_whence == SEEK_CUR)
			        fl.l_start += offset;

#if CONFIG_MACF
			error = mac_file_check_lock(proc_ucred(p), fp->f_fglob,
			    F_GETLK, &fl);
			if (error == 0)
#endif
			error = VNOP_ADVLOCK(vp, (caddr_t)p, F_GETLK, &fl, F_POSIX, &context);

			(void)vnode_put(vp);

			if (error == 0)
				error = copyout((caddr_t)&fl, argp, sizeof(fl));
		}
		goto outdrop;

	case F_PREALLOCATE: {
		fstore_t alloc_struct;    /* structure for allocate command */
		u_int32_t alloc_flags = 0;

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}

		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		/* make sure that we have write permission */
		if ((fp->f_flag & FWRITE) == 0) {
			error = EBADF;
			goto outdrop;
		}

		error = copyin(argp, (caddr_t)&alloc_struct, sizeof(alloc_struct));
		if (error)
			goto outdrop;

		/* now set the space allocated to 0 */
		alloc_struct.fst_bytesalloc = 0;
		
		/*
		 * Do some simple parameter checking
		 */

		/* set up the flags */

		alloc_flags |= PREALLOCATE;
		
		if (alloc_struct.fst_flags & F_ALLOCATECONTIG)
			alloc_flags |= ALLOCATECONTIG;

		if (alloc_struct.fst_flags & F_ALLOCATEALL)
			alloc_flags |= ALLOCATEALL;

		/*
		 * Do any position mode specific stuff.  The only
		 * position mode  supported now is PEOFPOSMODE
		 */

		switch (alloc_struct.fst_posmode) {
	
		case F_PEOFPOSMODE:
			if (alloc_struct.fst_offset != 0) {
				error = EINVAL;
				goto outdrop;
			}

			alloc_flags |= ALLOCATEFROMPEOF;
			break;

		case F_VOLPOSMODE:
			if (alloc_struct.fst_offset <= 0) {
				error = EINVAL;
				goto outdrop;
			}

			alloc_flags |= ALLOCATEFROMVOL;
			break;

		default: {
			error = EINVAL;
			goto outdrop;
			}
		}
		if ( (error = vnode_getwithref(vp)) == 0 ) {
		        /*
			 * call allocate to get the space
			 */
		        error = VNOP_ALLOCATE(vp,alloc_struct.fst_length,alloc_flags,
					      &alloc_struct.fst_bytesalloc, alloc_struct.fst_offset,
					      &context);
			(void)vnode_put(vp);

			error2 = copyout((caddr_t)&alloc_struct, argp, sizeof(alloc_struct));

			if (error == 0)
				error = error2;
		}
		goto outdrop;
		
		}
	case F_SETSIZE:
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		error = copyin(argp, (caddr_t)&offset, sizeof (off_t));
		if (error)
			goto outdrop;

		error = vnode_getwithref(vp);
		if (error)
			goto outdrop;

#if CONFIG_MACF
		error = mac_vnode_check_truncate(&context,
		    fp->f_fglob->fg_cred, vp);
		if (error) {
			(void)vnode_put(vp);
			goto outdrop;
		}
#endif
		/*
		 * Make sure that we are root.  Growing a file
		 * without zero filling the data is a security hole 
		 * root would have access anyway so we'll allow it
		 */
		if (!is_suser()) {
			error = EACCES;
		} else {
			/*
			 * set the file size
			 */
			error = vnode_setsize(vp, offset, IO_NOZEROFILL,
			    &context);
		}

		(void)vnode_put(vp);
		goto outdrop;

	case F_RDAHEAD:
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		if (uap->arg)
		        fp->f_fglob->fg_flag &= ~FNORDAHEAD;
		else
		        fp->f_fglob->fg_flag |= FNORDAHEAD;

		goto out;

	case F_NOCACHE:
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		if (uap->arg)
		        fp->f_fglob->fg_flag |= FNOCACHE;
		else
		        fp->f_fglob->fg_flag &= ~FNOCACHE;

		goto out;

	case F_GLOBAL_NOCACHE:
	        if (fp->f_type != DTYPE_VNODE) {
		        error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if ( (error = vnode_getwithref(vp)) == 0 ) {

		        *retval = vnode_isnocache(vp);

			if (uap->arg)
			        vnode_setnocache(vp);
			else
			        vnode_clearnocache(vp);

			(void)vnode_put(vp);
		}
		goto outdrop;

	case F_CHECK_OPENEVT:
	        if (fp->f_type != DTYPE_VNODE) {
		        error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if ( (error = vnode_getwithref(vp)) == 0 ) {

		        *retval = vnode_is_openevt(vp);

			if (uap->arg)
			        vnode_set_openevt(vp);
			else
			        vnode_clear_openevt(vp);

			(void)vnode_put(vp);
		}
		goto outdrop;

	case F_RDADVISE: {
		struct radvisory ra_struct;

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if ( (error = copyin(argp, (caddr_t)&ra_struct, sizeof(ra_struct))) )
			goto outdrop;
		if ( (error = vnode_getwithref(vp)) == 0 ) {
		        error = VNOP_IOCTL(vp, F_RDADVISE, (caddr_t)&ra_struct, 0, &context);

			(void)vnode_put(vp);
		}
		goto outdrop;
		}

	case F_READBOOTSTRAP:
	case F_WRITEBOOTSTRAP: {
		fbootstraptransfer_t fbt_struct;
		user_fbootstraptransfer_t user_fbt_struct;
		int	sizeof_struct;
		caddr_t boot_structp;

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if (IS_64BIT_PROCESS(p)) {
			sizeof_struct = sizeof(user_fbt_struct);
			boot_structp = (caddr_t) &user_fbt_struct;
		}
		else {
			sizeof_struct = sizeof(fbt_struct);
			boot_structp = (caddr_t) &fbt_struct;
		}
		error = copyin(argp, boot_structp, sizeof_struct);
		if (error)
			goto outdrop;
		if ( (error = vnode_getwithref(vp)) ) {
			goto outdrop;
		}
		if (uap->cmd == F_WRITEBOOTSTRAP) {
		        /*
			 * Make sure that we are root.  Updating the
			 * bootstrap on a disk could be a security hole
			 */
			if (!is_suser()) {
				(void)vnode_put(vp);
				error = EACCES;
				goto outdrop;
			}
		}
		if (strncmp(vnode_mount(vp)->mnt_vfsstat.f_fstypename, "hfs",
			sizeof(vnode_mount(vp)->mnt_vfsstat.f_fstypename)) != 0) {
			error = EINVAL;
		} else {
			/*
			 * call vnop_ioctl to handle the I/O
			 */
			error = VNOP_IOCTL(vp, uap->cmd, boot_structp, 0, &context);
		}
		(void)vnode_put(vp);
		goto outdrop;
	}
	case F_LOG2PHYS: {
		struct log2phys l2p_struct;    /* structure for allocate command */

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);
		if ( (error = vnode_getwithref(vp)) ) {
			goto outdrop;
		}
		error = VNOP_OFFTOBLK(vp, fp->f_offset, &lbn);
		if (error) {
			(void)vnode_put(vp);
			goto outdrop;
		}
		error = VNOP_BLKTOOFF(vp, lbn, &offset);
		if (error) {
			(void)vnode_put(vp);
			goto outdrop;
		}
		devBlockSize = vfs_devblocksize(vnode_mount(vp));

		error = VNOP_BLOCKMAP(vp, offset, devBlockSize, &bn, NULL, NULL, 0, &context);

		(void)vnode_put(vp);

		if (!error) {
			l2p_struct.l2p_flags = 0;	/* for now */
			l2p_struct.l2p_contigbytes = 0;	/* for now */
			l2p_struct.l2p_devoffset = bn * devBlockSize;
			l2p_struct.l2p_devoffset += fp->f_offset - offset;
			error = copyout((caddr_t)&l2p_struct, argp, sizeof(l2p_struct));
		}
		goto outdrop;
		}
	case F_GETPATH: {
		char *pathbufp;
		int pathlen;

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		pathlen = MAXPATHLEN;
		MALLOC(pathbufp, char *, pathlen, M_TEMP, M_WAITOK);
		if (pathbufp == NULL) {
			error = ENOMEM;
			goto outdrop;
		}
		if ( (error = vnode_getwithref(vp)) == 0 ) {
		        error = vn_getpath(vp, pathbufp, &pathlen);
		        (void)vnode_put(vp);

			if (error == 0)
			        error = copyout((caddr_t)pathbufp, argp, pathlen);
		}
		FREE(pathbufp, M_TEMP);
		goto outdrop;
	}

	case F_PATHPKG_CHECK: {
		char *pathbufp;
		size_t pathlen;

		if (fp->f_type != DTYPE_VNODE) {
		        error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		pathlen = MAXPATHLEN;
		pathbufp = kalloc(MAXPATHLEN);

		if ( (error = copyinstr(argp, pathbufp, MAXPATHLEN, &pathlen)) == 0 ) {
		        if ( (error = vnode_getwithref(vp)) == 0 ) {
			        error = vn_path_package_check(vp, pathbufp, pathlen, retval);

				(void)vnode_put(vp);
			}
		}
		kfree(pathbufp, MAXPATHLEN);
		goto outdrop;
	}

	case F_CHKCLEAN:   // used by regression tests to see if all dirty pages got cleaned by fsync()
	case F_FULLFSYNC:  // fsync + flush the journal + DKIOCSYNCHRONIZECACHE
	case F_FREEZE_FS:  // freeze all other fs operations for the fs of this fd
	case F_THAW_FS: {  // thaw all frozen fs operations for the fs of this fd
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if ( (error = vnode_getwithref(vp)) == 0 ) {
		        error = VNOP_IOCTL(vp, uap->cmd, (caddr_t)NULL, 0, &context);

			(void)vnode_put(vp);
		}
		break;
	}

	/*
	 * SPI (private) for opening a file starting from a dir fd
	 */
	case F_OPENFROM: {
		struct user_fopenfrom fopen;
		struct vnode_attr va;
		struct nameidata nd;
		int cmode;

		/* Check if this isn't a valid file descriptor */
		if ((fp->f_type != DTYPE_VNODE) ||
		    (fp->f_flag & FREAD) == 0) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if (vnode_getwithref(vp)) {
			error = ENOENT;
			goto outdrop;
		}
		
		/* Only valid for directories */
		if (vp->v_type != VDIR) {
			vnode_put(vp);
			error = ENOTDIR;
			goto outdrop;
		}

		/* Get flags, mode and pathname arguments. */
		if (IS_64BIT_PROCESS(p)) {
			error = copyin(argp, &fopen, sizeof(fopen));
		} else {
			struct fopenfrom fopen32;

			error = copyin(argp, &fopen32, sizeof(fopen32));
			fopen.o_flags = fopen32.o_flags;
			fopen.o_mode = fopen32.o_mode;
			fopen.o_pathname = CAST_USER_ADDR_T(fopen32.o_pathname);
		}
		if (error) {
			vnode_put(vp);
			goto outdrop;
		}
		VATTR_INIT(&va);
		/* Mask off all but regular access permissions */
		cmode = ((fopen.o_mode &~ fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
		VATTR_SET(&va, va_mode, cmode & ACCESSPERMS);

		/* Start the lookup relative to the file descriptor's vnode. */
		NDINIT(&nd, LOOKUP, USEDVP | FOLLOW | AUDITVNPATH1, UIO_USERSPACE,
		       fopen.o_pathname, &context);
		nd.ni_dvp = vp;

		error = open1(&context, &nd, fopen.o_flags, &va, retval);

		vnode_put(vp);
		break;
	}
	/*
	 * SPI (private) for unlinking a file starting from a dir fd
	 */
	case F_UNLINKFROM: {
		struct nameidata nd;
		user_addr_t pathname;

		/* Check if this isn't a valid file descriptor */
		if ((fp->f_type != DTYPE_VNODE) ||
		    (fp->f_flag & FREAD) == 0) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if (vnode_getwithref(vp)) {
			error = ENOENT;
			goto outdrop;
		}
		
		/* Only valid for directories */
		if (vp->v_type != VDIR) {
			vnode_put(vp);
			error = ENOTDIR;
			goto outdrop;
		}

		/* Get flags, mode and pathname arguments. */
		if (IS_64BIT_PROCESS(p)) {
			pathname = (user_addr_t)argp;
		} else {
			pathname = CAST_USER_ADDR_T(argp);
		}

		/* Start the lookup relative to the file descriptor's vnode. */
		NDINIT(&nd, DELETE, USEDVP | AUDITVNPATH1, UIO_USERSPACE, pathname, &context);
		nd.ni_dvp = vp;

		error = unlink1(&context, &nd, 0);
		
		vnode_put(vp);
		break;

	}

	case F_ADDSIGS: {
		struct user_fsignatures fs;
		kern_return_t kr;
		vm_address_t kernel_blob_addr;
		vm_size_t kernel_blob_size;

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);
		error = vnode_getwithref(vp);
		if (error)
			goto outdrop;

		if (IS_64BIT_PROCESS(p)) {
			error = copyin(argp, &fs, sizeof (fs));
		} else {
			struct fsignatures fs32;

			error = copyin(argp, &fs32, sizeof (fs32));
			fs.fs_file_start = fs32.fs_file_start;
			fs.fs_blob_start = CAST_USER_ADDR_T(fs32.fs_blob_start);
			fs.fs_blob_size = fs32.fs_blob_size;
		}

		if (error) {
			vnode_put(vp);
			goto outdrop;
		}

		if(ubc_cs_blob_get(vp, CPU_TYPE_ANY, fs.fs_file_start))
		{
			if(cs_debug)
				printf("CODE SIGNING: resident blob offered for: %s\n", vp->v_name);
			vnode_put(vp);
			goto outdrop;
		}
				   
#define CS_MAX_BLOB_SIZE (1ULL * 1024 * 1024) /* XXX ? */
		if (fs.fs_blob_size > CS_MAX_BLOB_SIZE) {
			error = E2BIG;
			vnode_put(vp);
			goto outdrop;
		}

		kernel_blob_size = CAST_DOWN(vm_size_t, fs.fs_blob_size);
		kr = ubc_cs_blob_allocate(&kernel_blob_addr, &kernel_blob_size);
		if (kr != KERN_SUCCESS) {
			error = ENOMEM;
			vnode_put(vp);
			goto outdrop;
		}

		error = copyin(fs.fs_blob_start,
			       (void *) kernel_blob_addr,
			       kernel_blob_size);
		if (error) {
			ubc_cs_blob_deallocate(kernel_blob_addr,
					       kernel_blob_size);
			vnode_put(vp);
			goto outdrop;
		}

		error = ubc_cs_blob_add(
			vp,
			CPU_TYPE_ANY,	/* not for a specific architecture */
			fs.fs_file_start,
			kernel_blob_addr,
			kernel_blob_size);
		if (error) {
			ubc_cs_blob_deallocate(kernel_blob_addr,
					       kernel_blob_size);
		} else {
			/* ubc_blob_add() has consumed "kernel_blob_addr" */
		}

		(void) vnode_put(vp);
		break;
	}

	case F_MARKDEPENDENCY: {
		struct vnode *root_vp;
		struct vnode_attr va;
		vfs_context_t ctx = vfs_context_current();
		kauth_cred_t cred;

		if ((current_proc()->p_flag & P_DEPENDENCY_CAPABLE) == 0) {
		    error = EPERM;
		    goto out;
		}
		
		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}

		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if (vnode_getwithref(vp)) {
			error = ENOENT;
			goto outdrop;
		}

		// the passed in vnode must be the root dir of the file system
		if (VFS_ROOT(vp->v_mount, &root_vp, ctx) != 0 || vp != root_vp) {
		    error = EINVAL;
		    vnode_put(vp);
		    goto outdrop;
		}
		vnode_put(root_vp);

		// get the owner of the root dir
		VATTR_INIT(&va);
		VATTR_WANTED(&va, va_uid);
		if (vnode_getattr(vp, &va, ctx) != 0) {
		    error = EINVAL;
		    vnode_put(vp);
		    goto outdrop;
		}

		// and last, check that the caller is the super user or
		// the owner of the mount point
		cred = vfs_context_ucred(ctx);
		if (!is_suser() && va.va_uid != kauth_cred_getuid(cred)) {
			error = EACCES;
			vnode_put(vp);
			goto outdrop;
		}

		// if all those checks pass then we can mark the dependency
		vfs_markdependency(vp->v_mount);
		error = 0;

		vnode_put(vp);
		
		break;
	}

	default:
		if (uap->cmd < FCNTL_FS_SPECIFIC_BASE) {
			error = EINVAL;
			goto out;
		}

		// if it's a fs-specific fcntl() then just pass it through

		if (fp->f_type != DTYPE_VNODE) {
			error = EBADF;
			goto out;
		}
		vp = (struct vnode *)fp->f_data;
		proc_fdunlock(p);

		if ( (error = vnode_getwithref(vp)) == 0 ) {
			error = VNOP_IOCTL(vp, uap->cmd, CAST_DOWN(caddr_t, argp), 0, &context);

			(void)vnode_put(vp);
		}
		break;
	
	}

outdrop:
	AUDIT_ARG(vnpath_withref, vp, ARG_VNODE1);
	fp_drop(p, fd, fp, 0);
	return(error);
out:
	fp_drop(p, fd, fp, 1);
	proc_fdunlock(p);
	return(error);
}


/*
 * finishdup
 *
 * Description:	Common code for dup, dup2, and fcntl(F_DUPFD).
 *
 * Parameters:	p				Process performing the dup
 *		old				The fd to dup
 *		new				The fd to dup it to
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		EBADF
 *		ENOMEM
 *
 * Implicit returns:
 *		*retval (modified)		The new descriptor
 *
 * Locks:	Assumes proc_fdlock for process pointing to fdp is held by
 *		the caller
 *
 * Notes:	This function may drop and reacquire this lock; it is unsafe
 *		for a caller to assume that other state protected by the lock
 *		has not been subsequently changes out from under it.
 */
int
finishdup(proc_t p, struct filedesc *fdp, int old, int new, register_t *retval)
{
	struct fileproc *nfp;
	struct fileproc *ofp;
#if CONFIG_MACF
	int error;
#endif

#if DIAGNOSTIC
	proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif

	if ((ofp = fdp->fd_ofiles[old]) == NULL ||
			(fdp->fd_ofileflags[old] & UF_RESERVED)) {
		fdrelse(p, new);
		return (EBADF);
	}
	fg_ref(ofp);

#if CONFIG_MACF
	error = mac_file_check_dup(proc_ucred(p), ofp->f_fglob, new);
	if (error) {
		fg_drop(ofp);
		fdrelse(p, new);
		return (error);
	}
#endif

	proc_fdunlock(p);

	MALLOC_ZONE(nfp, struct fileproc *, sizeof(struct fileproc), M_FILEPROC, M_WAITOK);
	/* Failure check follows proc_fdlock() due to handling requirements */

	proc_fdlock(p);

	if (nfp == NULL) {
		fg_drop(ofp);
		fdrelse(p, new);
		return (ENOMEM);
	}

	bzero(nfp, sizeof(struct fileproc));

	nfp->f_flags = 0;
	nfp->f_fglob = ofp->f_fglob;
	nfp->f_iocount = 0;

#if DIAGNOSTIC
	if (fdp->fd_ofiles[new] != 0)
		panic("finishdup: overwriting fd_ofiles with new %d\n", new);
	if ((fdp->fd_ofileflags[new] & UF_RESERVED) == 0)
		panic("finishdup: unreserved  fileflags  with new %d\n", new);
#endif

	if (new > fdp->fd_lastfile)
		fdp->fd_lastfile = new;
	procfdtbl_releasefd(p, new, nfp);
	*retval = new;
	return (0);
}


/*
 * close
 *
 * Description:	The implementation of the close(2) system call
 *
 * Parameters:	p			Process in whose per process file table
 *					the close is to occur
 *		uap->fd			fd to be closed
 *		retval			<unused>
 *
 * Returns:	0			Success
 *	fp_lookup:EBADF			Bad file descriptor
 *	close_internal:EBADF
 *	close_internal:??? 		Anything returnable by a per-fileops
 *					close function
 */
int
close(proc_t p, struct close_args *uap, register_t *retval)
{
	__pthread_testcancel(1);
	return(close_nocancel(p, (struct close_nocancel_args *)uap, retval));
}


int
close_nocancel(proc_t p, struct close_nocancel_args *uap, __unused register_t *retval)
{
	struct fileproc *fp;
	int fd = uap->fd;
	int error =0;

	AUDIT_SYSCLOSE(p, fd);

	proc_fdlock(p);

	if ( (error = fp_lookup(p,fd,&fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}

	error = close_internal_locked(p, fd, fp, 0);

	proc_fdunlock(p);

	return(error);
}


/*
 * close_internal_locked
 *
 * Close a file descriptor.
 *
 * Parameters:	p			Process in whose per process file table
 *					the close is to occur
 *		fd			fd to be closed
 *		fp			fileproc associated with the fd
 *
 * Returns:	0			Success
 *		EBADF			fd already in close wait state
 *	closef_locked:??? 		Anything returnable by a per-fileops
 *					close function
 *
 * Locks:	Assumes proc_fdlock for process is held by the caller and returns
 *		with lock held
 *
 * Notes:	This function may drop and reacquire this lock; it is unsafe
 *		for a caller to assume that other state protected by the lock
 *		has not been subsequently changes out from under it, if the
 *		caller made the call with the lock held.
 */
static int
close_internal_locked(proc_t p, int fd, struct fileproc *fp, int flags)
{
	struct filedesc *fdp = p->p_fd;
	int error =0;
	int resvfd = flags & FD_DUP2RESV;


#if DIAGNOSTIC
	proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif

	/* Keep people from using the filedesc while we are closing it */
	procfdtbl_markclosefd(p, fd);


	if ((fp->f_flags & FP_CLOSING) == FP_CLOSING) {
		panic("close_internal_locked:  being called on already closing fd\n");
	}


#if DIAGNOSTIC
	if ((fdp->fd_ofileflags[fd] & UF_RESERVED) == 0)
		panic("close_internal: unreserved  fileflags  with fd %d\n", fd);
#endif

	fp->f_flags |= FP_CLOSING;

	if ( (fp->f_flags & FP_AIOISSUED) || kauth_authorize_fileop_has_listeners() ) {

	        proc_fdunlock(p);

		if ( (fp->f_type == DTYPE_VNODE) && kauth_authorize_fileop_has_listeners() ) {
		        /*
			 * call out to allow 3rd party notification of close. 
			 * Ignore result of kauth_authorize_fileop call.
			 */
		        if (vnode_getwithref((vnode_t)fp->f_data) == 0) {
		        	u_int	fileop_flags = 0;
		        	if ((fp->f_flags & FP_WRITTEN) != 0)
		        		fileop_flags |= KAUTH_FILEOP_CLOSE_MODIFIED;
			        kauth_authorize_fileop(fp->f_fglob->fg_cred, KAUTH_FILEOP_CLOSE, 
						       (uintptr_t)fp->f_data, (uintptr_t)fileop_flags);
				vnode_put((vnode_t)fp->f_data);
			}
		}
		if (fp->f_flags & FP_AIOISSUED)
		        /*
			 * cancel all async IO requests that can be cancelled.
			 */
		        _aio_close( p, fd );

		proc_fdlock(p);
	}

	if (fd < fdp->fd_knlistsize)
		knote_fdclose(p, fd);

	if (fp->f_flags & FP_WAITEVENT) 
		(void)waitevent_close(p, fp);

	if ((fp->f_flags & FP_INCHRREAD) == 0)
		fileproc_drain(p, fp);

	if (resvfd == 0)
		_fdrelse(p, fd);

	error = closef_locked(fp, fp->f_fglob, p);
	if ((fp->f_flags & FP_WAITCLOSE) == FP_WAITCLOSE)
		wakeup(&fp->f_flags);
	fp->f_flags &= ~(FP_WAITCLOSE | FP_CLOSING);

	proc_fdunlock(p);

	FREE_ZONE(fp, sizeof(*fp), M_FILEPROC);	

	proc_fdlock(p);

#if DIAGNOSTIC
	if (resvfd != 0) {
		if ((fdp->fd_ofileflags[fd] & UF_RESERVED) == 0)
			panic("close with reserved fd returns with freed fd:%d: proc: %x\n", fd, (unsigned int)p);
	}
#endif

	return(error);
}


/*
 * fstat1
 *
 * Description:	Return status information about a file descriptor.
 *
 * Parameters:	p				The process doing the fstat
 *		fd				The fd to stat
 *		ub				The user stat buffer
 *		xsecurity			The user extended security
 *						buffer, or 0 if none
 *		xsecurity_size			The size of xsecurity, or 0
 *						if no xsecurity
 *		isstat64			Flag to indicate 64 bit version
 *						for inode size, etc.
 *
 * Returns:	0				Success
 *		EBADF
 *		EFAULT
 *	fp_lookup:EBADF				Bad file descriptor
 *	vnode_getwithref:???
 *	copyout:EFAULT
 *	vnode_getwithref:???
 *	vn_stat:???
 *	soo_stat:???
 *	pipe_stat:???
 *	pshm_stat:???
 *	kqueue_stat:???
 *
 * Notes:	Internal implementation for all other fstat() related
 *		functions
 *
 *		XXX switch on node type is bogus; need a stat in struct
 *		XXX fileops instead.
 */
static int
fstat1(proc_t p, int fd, user_addr_t ub, user_addr_t xsecurity, user_addr_t xsecurity_size, int isstat64)
{
	struct fileproc *fp;
	struct stat sb;
	struct stat64 sb64;
	struct user_stat user_sb;
	struct user_stat64 user_sb64;
	int error, my_size;
	int funnel_state;
	file_type_t type;
	caddr_t data;
	kauth_filesec_t fsec;
	user_size_t xsecurity_bufsize;
	vfs_context_t ctx = vfs_context_current();
	void * sbptr;


	AUDIT_ARG(fd, fd);

	if ((error = fp_lookup(p, fd, &fp, 0)) != 0) {
		return(error);
	}
	type = fp->f_type;
	data = fp->f_data;
	fsec = KAUTH_FILESEC_NONE;

	sbptr = (isstat64 != 0) ? (void *)&sb64: (void *)&sb;

	switch (type) {

	case DTYPE_VNODE:
		if ((error = vnode_getwithref((vnode_t)data)) == 0) {
			/*
			 * If the caller has the file open, and is not
			 * requesting extended security information, we are
			 * going to let them get the basic stat information.
			 */
			if (xsecurity == USER_ADDR_NULL) {
				error = vn_stat_noauth((vnode_t)data, sbptr, NULL, isstat64, ctx);
			} else {
				error = vn_stat((vnode_t)data, sbptr, &fsec, isstat64, ctx);
			}

			AUDIT_ARG(vnpath, (struct vnode *)data, ARG_VNODE1);
			(void)vnode_put((vnode_t)data);
		}
		break;

#if SOCKETS
	case DTYPE_SOCKET:
		error = soo_stat((struct socket *)data, sbptr, isstat64);
		break;
#endif /* SOCKETS */

	case DTYPE_PIPE:
		error = pipe_stat((void *)data, sbptr, isstat64);
		break;

	case DTYPE_PSXSHM:
		error = pshm_stat((void *)data, sbptr, isstat64);
		break;

	case DTYPE_KQUEUE:
	        funnel_state = thread_funnel_set(kernel_flock, TRUE);
		error = kqueue_stat(fp, sbptr, isstat64, p);
		thread_funnel_set(kernel_flock, funnel_state);
		break;

	default:
		error = EBADF;
		goto out;
	}
	if (error == 0) {
		caddr_t sbp;

		if (isstat64 != 0) {
			sb64.st_lspare = 0;
			sb64.st_qspare[0] = 0LL;
			sb64.st_qspare[1] = 0LL;
			if (IS_64BIT_PROCESS(current_proc())) {
				munge_stat64(&sb64, &user_sb64); 
				my_size = sizeof(user_sb64);
				sbp = (caddr_t)&user_sb64;
			} else {
				my_size = sizeof(sb64);
				sbp = (caddr_t)&sb64;
			}
		} else {
			sb.st_lspare = 0;
			sb.st_qspare[0] = 0LL;
			sb.st_qspare[1] = 0LL;
			if (IS_64BIT_PROCESS(current_proc())) {
				munge_stat(&sb, &user_sb); 
				my_size = sizeof(user_sb);
				sbp = (caddr_t)&user_sb;
			} else {
				my_size = sizeof(sb);
				sbp = (caddr_t)&sb;
			}
		}

		error = copyout(sbp, ub, my_size);
	}

	/* caller wants extended security information? */
	if (xsecurity != USER_ADDR_NULL) {

		/* did we get any? */
		 if (fsec == KAUTH_FILESEC_NONE) {
			if (susize(xsecurity_size, 0) != 0) {
				error = EFAULT;
				goto out;
			}
		} else {
			/* find the user buffer size */
			xsecurity_bufsize = fusize(xsecurity_size);

			/* copy out the actual data size */
			if (susize(xsecurity_size, KAUTH_FILESEC_COPYSIZE(fsec)) != 0) {
				error = EFAULT;
				goto out;
			}

			/* if the caller supplied enough room, copy out to it */
			if (xsecurity_bufsize >= KAUTH_FILESEC_COPYSIZE(fsec))
				error = copyout(fsec, xsecurity, KAUTH_FILESEC_COPYSIZE(fsec));
		}
	}
out:
	fp_drop(p, fd, fp, 0);
	if (fsec != NULL)
		kauth_filesec_free(fsec);
	return (error);
}


/*
 * fstat_extended
 *
 * Description:	Extended version of fstat supporting returning extended
 *		security information
 *
 * Parameters:	p				The process doing the fstat
 *		uap->fd				The fd to stat
 *		uap->ub				The user stat buffer
 *		uap->xsecurity			The user extended security
 *						buffer, or 0 if none
 *		uap->xsecurity_size		The size of xsecurity, or 0
 *
 * Returns:	0				Success
 *		!0				Errno (see fstat1)
 */
int
fstat_extended(proc_t p, struct fstat_extended_args *uap, __unused register_t *retval)
{
	return(fstat1(p, uap->fd, uap->ub, uap->xsecurity, uap->xsecurity_size, 0));
}
 

/*
 * fstat
 *
 * Description:	Get file status for the file associated with fd
 *
 * Parameters:	p				The process doing the fstat
 *		uap->fd				The fd to stat
 *		uap->ub				The user stat buffer
 *
 * Returns:	0				Success
 *		!0				Errno (see fstat1)
 */
int
fstat(proc_t p, register struct fstat_args *uap, __unused register_t *retval)
{
	return(fstat1(p, uap->fd, uap->ub, 0, 0, 0));
}


/*
 * fstat64_extended
 *
 * Description:	Extended version of fstat64 supporting returning extended
 *		security information
 *
 * Parameters:	p				The process doing the fstat
 *		uap->fd				The fd to stat
 *		uap->ub				The user stat buffer
 *		uap->xsecurity			The user extended security
 *						buffer, or 0 if none
 *		uap->xsecurity_size		The size of xsecurity, or 0
 *
 * Returns:	0				Success
 *		!0				Errno (see fstat1)
 */
int
fstat64_extended(proc_t p, struct fstat64_extended_args *uap, __unused register_t *retval)
{
	return(fstat1(p, uap->fd, uap->ub, uap->xsecurity, uap->xsecurity_size, 1));
}
 

/*
 * fstat64
 *
 * Description:	Get 64 bit version of the file status for the file associated
 *		with fd
 *
 * Parameters:	p				The process doing the fstat
 *		uap->fd				The fd to stat
 *		uap->ub				The user stat buffer
 *
 * Returns:	0				Success
 *		!0				Errno (see fstat1)
 */
int
fstat64(proc_t p, register struct fstat64_args *uap, __unused register_t *retval)
{
	return(fstat1(p, uap->fd, uap->ub, 0, 0, 1));
}


/*
 * fpathconf
 *
 * Description:	Return pathconf information about a file descriptor.
 *
 * Parameters:	p				Process making the request
 *		uap->fd				fd to get information about
 *		uap->name			Name of information desired
 *		retval				Pointer to the call return area
 *
 * Returns:	0				Success
 *		EINVAL
 *	fp_lookup:EBADF				Bad file descriptor
 *	vnode_getwithref:???
 *	vn_pathconf:???
 *
 * Implicit returns:
 *		*retval (modified)		Returned information (numeric)
 */
int
fpathconf(proc_t p, struct fpathconf_args *uap, register_t *retval)
{
	int fd = uap->fd;
	struct fileproc *fp;
	struct vnode *vp;
	int error = 0;
	file_type_t type;
	caddr_t data;


	AUDIT_ARG(fd, uap->fd);
	if ( (error = fp_lookup(p, fd, &fp, 0)) )
		return(error);
	type = fp->f_type;
	data = fp->f_data;

	switch (type) {

	case DTYPE_SOCKET:
	        if (uap->name != _PC_PIPE_BUF) {
		        error = EINVAL;
			goto out;
		}
		*retval = PIPE_BUF;
		error = 0;
		goto out;

	case DTYPE_PIPE:
	        *retval = PIPE_BUF;
		error = 0;
		goto out;

	case DTYPE_VNODE:
		vp = (struct vnode *)data;

		if ( (error = vnode_getwithref(vp)) == 0) {
		        AUDIT_ARG(vnpath, vp, ARG_VNODE1);

			error = vn_pathconf(vp, uap->name, retval, vfs_context_current());

			(void)vnode_put(vp);
		}
		goto out;

	case DTYPE_PSXSHM:
	case DTYPE_PSXSEM:
	case DTYPE_KQUEUE:
	case DTYPE_FSEVENTS:
		error = EINVAL;
		goto out;

	}
	/*NOTREACHED*/
out:
	fp_drop(p, fd, fp, 0);
	return(error);
}

/*
 * Statistics counter for the number of times a process calling fdalloc()
 * has resulted in an expansion of the per process open file table.
 *
 * XXX This would likely be of more use if it were per process
 */
int fdexpand;


/*
 * fdalloc
 *
 * Description:	Allocate a file descriptor for the process.
 *
 * Parameters:	p				Process to allocate the fd in
 *		want				The fd we would prefer to get
 *		result				Pointer to fd we got
 *
 * Returns:	0				Success
 *		EMFILE
 *		ENOMEM
 *
 * Implicit returns:
 *		*result (modified)		The fd which was allocated
 */
int
fdalloc(proc_t p, int want, int *result)
{
	struct filedesc *fdp = p->p_fd;
	int i;
	int lim, last, numfiles, oldnfiles;
	struct fileproc **newofiles, **ofiles;
	char *newofileflags;

	/*
	 * Search for a free descriptor starting at the higher
	 * of want or fd_freefile.  If that fails, consider
	 * expanding the ofile array.
	 */
#if DIAGNOSTIC
	proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
#endif

	lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
	for (;;) {
		last = min(fdp->fd_nfiles, lim);
		if ((i = want) < fdp->fd_freefile)
			i = fdp->fd_freefile;
		for (; i < last; i++) {
			if (fdp->fd_ofiles[i] == NULL && !(fdp->fd_ofileflags[i] & UF_RESERVED)) {
				procfdtbl_reservefd(p, i);
				if (i > fdp->fd_lastfile)
					fdp->fd_lastfile = i;
				if (want <= fdp->fd_freefile)
					fdp->fd_freefile = i;
				*result = i;
				return (0);
			}
		}

		/*
		 * No space in current array.  Expand?
		 */
		if (fdp->fd_nfiles >= lim)
			return (EMFILE);
		if (fdp->fd_nfiles < NDEXTENT)
			numfiles = NDEXTENT;
		else
			numfiles = 2 * fdp->fd_nfiles;
		/* Enforce lim */
		if (numfiles > lim)
			numfiles = lim;
		proc_fdunlock(p);
		MALLOC_ZONE(newofiles, struct fileproc **,
				numfiles * OFILESIZE, M_OFILETABL, M_WAITOK);
		proc_fdlock(p);
		if (newofiles == NULL) {
			return (ENOMEM);
		}
		if (fdp->fd_nfiles >= numfiles) {
			FREE_ZONE(newofiles, numfiles * OFILESIZE, M_OFILETABL);
			continue;
		}
		newofileflags = (char *) &newofiles[numfiles];
		/*
		 * Copy the existing ofile and ofileflags arrays
		 * and zero the new portion of each array.
		 */
		oldnfiles = fdp->fd_nfiles;
		(void) memcpy(newofiles, fdp->fd_ofiles,
				oldnfiles * sizeof(*fdp->fd_ofiles));
		(void) memset(&newofiles[oldnfiles], 0,
				(numfiles - oldnfiles) * sizeof(*fdp->fd_ofiles));

		(void) memcpy(newofileflags, fdp->fd_ofileflags,
				oldnfiles * sizeof(*fdp->fd_ofileflags));
		(void) memset(&newofileflags[oldnfiles], 0,
				(numfiles - oldnfiles) *
						sizeof(*fdp->fd_ofileflags));
		ofiles = fdp->fd_ofiles;
		fdp->fd_ofiles = newofiles;
		fdp->fd_ofileflags = newofileflags;
		fdp->fd_nfiles = numfiles;
		FREE_ZONE(ofiles, oldnfiles * OFILESIZE, M_OFILETABL);
		fdexpand++;
	}
}


/*
 * fdavail
 *
 * Description:	Check to see whether n user file descriptors are available
 *		to the process p.
 *
 * Parameters:	p				Process to check in
 *		n				The number of fd's desired
 *
 * Returns:	0				No
 *		1				Yes
 *
 * Locks:	Assumes proc_fdlock for process is held by the caller
 *
 * Notes:	The answer only remains valid so long as the proc_fdlock is
 *		held by the caller.
 */
int
fdavail(proc_t p, int n)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc **fpp;
	char *flags;
	int i, lim;

	lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
	if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
		return (1);
	fpp = &fdp->fd_ofiles[fdp->fd_freefile];
	flags = &fdp->fd_ofileflags[fdp->fd_freefile];
	for (i = fdp->fd_nfiles - fdp->fd_freefile; --i >= 0; fpp++, flags++)
		if (*fpp == NULL && !(*flags & UF_RESERVED) && --n <= 0)
			return (1);
	return (0);
}


/*
 * fdrelse
 *
 * Description:	Legacy KPI wrapper function for _fdrelse
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to free
 *
 * Returns:	void
 *
 * Locks:	Assumes proc_fdlock for process is held by the caller
 */
void
fdrelse(proc_t p, int fd)
{
	_fdrelse(p, fd);
}


/*
 * fdgetf_noref
 *
 * Description:	Get the fileproc pointer for the given fd from the per process
 *		open file table without taking an explicit reference on it.
 *
 * Parameters:	p				Process containing fd
 *		fd				fd to obtain fileproc for
 *		resultfp			Pointer to pointer return area
 *
 * Returns:	0				Success
 *		EBADF
 *
 * Implicit returns:
 *		*resultfp (modified)		Pointer to fileproc pointer
 *
 * Locks:	Assumes proc_fdlock for process is held by the caller
 *
 * Notes:	Because there is no reference explicitly taken, the returned
 *		fileproc pointer is only valid so long as the proc_fdlock
 *		remains held by the caller.
 */
int
fdgetf_noref(proc_t p, int fd, struct fileproc **resultfp)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		return (EBADF);
	}
	if (resultfp)
		*resultfp = fp;
	return (0);
}


/*
 * fp_getfvp
 *
 * Description:	Get fileproc and vnode pointer for a given fd from the per
 *		process open file table of the specified process, and if
 *		successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultvp			Pointer to result vnode pointer
 *						area, or 0 if none
 *
 * Returns:	0				Success
 *		EBADF				Bad file descriptor
 *		ENOTSUP				fd does not refer to a vnode
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultvp (modified)		vnode pointer
 *
 * Notes:	The resultfp and resultvp fields are optional, and may be
 *		independently specified as NULL to skip returning information
 *
 * Locks:	Internally takes and releases proc_fdlock
 */
int
fp_getfvp(proc_t p, int fd, struct fileproc **resultfp, struct vnode **resultvp)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_VNODE) {
		proc_fdunlock(p);
		return(ENOTSUP);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultvp)
		*resultvp = (struct vnode *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfvpandvid
 *
 * Description:	Get fileproc, vnode pointer, and vid for a given fd from the
 *		per process open file table of the specified process, and if
 *		successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultvp			Pointer to result vnode pointer
 *						area, or 0 if none
 *		vidp				Pointer to resuld vid area
 *
 * Returns:	0				Success
 *		EBADF				Bad file descriptor
 *		ENOTSUP				fd does not refer to a vnode
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultvp (modified)		vnode pointer
 *		*vidp				vid value
 *
 * Notes:	The resultfp and resultvp fields are optional, and may be
 *		independently specified as NULL to skip returning information
 *
 * Locks:	Internally takes and releases proc_fdlock
 */
int
fp_getfvpandvid(proc_t p, int fd, struct fileproc **resultfp,
		struct vnode **resultvp, uint32_t *vidp)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_VNODE) {
		proc_fdunlock(p);
		return(ENOTSUP);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultvp)
		*resultvp = (struct vnode *)fp->f_data;
	if (vidp)
		*vidp = (uint32_t)vnode_vid((struct vnode *)fp->f_data);
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfsock
 *
 * Description:	Get fileproc and socket pointer for a given fd from the
 *		per process open file table of the specified process, and if
 *		successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		results				Pointer to result socket
 *						pointer area, or 0 if none
 *
 * Returns:	EBADF			The file descriptor is invalid
 *		EOPNOTSUPP		The file descriptor is not a socket
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*results (modified)		socket pointer
 *
 * Notes:	EOPNOTSUPP should probably be ENOTSOCK; this function is only
 *		ever called from accept1().
 */
int
fp_getfsock(proc_t p, int fd, struct fileproc **resultfp,
	    struct socket **results)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_SOCKET) {
		proc_fdunlock(p);
		return(EOPNOTSUPP);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (results)
		*results = (struct socket *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfkq
 *
 * Description:	Get fileproc and kqueue pointer for a given fd from the
 *		per process open file table of the specified process, and if
 *		successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultkq			Pointer to result kqueue
 *						pointer area, or 0 if none
 *
 * Returns:	EBADF			The file descriptor is invalid
 *		EBADF			The file descriptor is not a socket
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultkq (modified)		kqueue pointer
 *
 * Notes:	The second EBADF should probably be something else to make
 *		the error condition distinct.
 */
int
fp_getfkq(proc_t p, int fd, struct fileproc **resultfp,
	  struct kqueue **resultkq)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if ( fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_KQUEUE) {
		proc_fdunlock(p);
		return(EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultkq)
		*resultkq = (struct kqueue *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfpshm
 *
 * Description:	Get fileproc and POSIX shared memory pointer for a given fd
 *		from the per process open file table of the specified process
 *		and if successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultpshm			Pointer to result POSIX
 *						shared memory pointer
 *						pointer area, or 0 if none
 *
 * Returns:	EBADF			The file descriptor is invalid
 *		EBADF			The file descriptor is not a POSIX
 *					shared memory area
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultpshm (modified)		POSIX shared memory pointer
 *
 * Notes:	The second EBADF should probably be something else to make
 *		the error condition distinct.
 */
int
fp_getfpshm(proc_t p, int fd, struct fileproc **resultfp,
	    struct pshmnode **resultpshm)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_PSXSHM) {

		proc_fdunlock(p);
		return(EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultpshm)
		*resultpshm = (struct pshmnode *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfsem
 *
 * Description:	Get fileproc and POSIX semaphore pointer for a given fd from
 *		the per process open file table of the specified process
 *		and if successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultpsem			Pointer to result POSIX
 *						semaphore pointer area, or
 *						0 if none
 *
 * Returns:	EBADF			The file descriptor is invalid
 *		EBADF			The file descriptor is not a POSIX
 *					semaphore
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultpsem (modified)		POSIX semaphore pointer
 *
 * Notes:	The second EBADF should probably be something else to make
 *		the error condition distinct.
 *
 *		In order to support unnamed POSIX semaphores, the named
 *		POSIX semaphores will have to move out of the per-process
 *		open filetable, and into a global table that is shared with
 *		unnamed POSIX semaphores, since unnamed POSIX semaphores
 *		are typically used by declaring instances in shared memory,
 *		and there's no other way to do this without changing the
 *		underlying type, which would introduce binary compatibility
 *		issues.
 */
int
fp_getfpsem(proc_t p, int fd, struct fileproc **resultfp,
	    struct psemnode **resultpsem)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_PSXSEM) {
		proc_fdunlock(p);
		return(EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultpsem)
		*resultpsem = (struct psemnode *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_getfpipe
 *
 * Description:	Get fileproc and pipe pointer for a given fd from the
 *		per process open file table of the specified process
 *		and if successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultpipe			Pointer to result pipe
 *						pointer area, or 0 if none
 *
 * Returns:	EBADF			The file descriptor is invalid
 *		EBADF			The file descriptor is not a socket
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultpipe (modified)		pipe pointer
 *
 * Notes:	The second EBADF should probably be something else to make
 *		the error condition distinct.
 */
int
fp_getfpipe(proc_t p, int fd, struct fileproc **resultfp,
	    struct pipe **resultpipe)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != DTYPE_PIPE) {
		proc_fdunlock(p);
		return(EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultpipe)
		*resultpipe = (struct pipe *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


#define DTYPE_ATALK -1		/* XXX This does not belong here */


/*
 * fp_getfatalk
 *
 * Description:	Get fileproc and atalk pointer for a given fd from the
 *		per process open file table of the specified process
 *		and if successful, increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		resultatalk			Pointer to result atalk
 *						pointer area, or 0 if none
 * Returns:	EBADF			The file descriptor is invalid
 *		EBADF			The file descriptor is not a socket
 *		0			Success
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *		*resultatalk (modified)		atalk pointer
 *
 * Notes:	The second EBADF should probably be something else to make
 *		the error condition distinct.
 *
 *		XXX This code is specific to AppleTalk protocol support, and
 *		XXX should be conditionally compiled
 */
int
fp_getfatalk(proc_t p, int fd, struct fileproc **resultfp,
	     struct atalk **resultatalk)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		proc_fdunlock(p);
		return (EBADF);
	}
	if (fp->f_type != (DTYPE_ATALK+1)) {
		proc_fdunlock(p);
		return(EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (resultatalk)
		*resultatalk = (struct atalk *)fp->f_data;
	proc_fdunlock(p);

	return (0);
}


/*
 * fp_lookup
 *
 * Description:	Get fileproc pointer for a given fd from the per process
 *		open file table of the specified process and if successful,
 *		increment the f_iocount
 *
 * Parameters:	p				Process in which fd lives
 *		fd				fd to get information for
 *		resultfp			Pointer to result fileproc
 *						pointer area, or 0 if none
 *		locked				!0 if the caller holds the
 *						proc_fdlock, 0 otherwise
 *
 * Returns:	0			Success
 *		EBADF			Bad file descriptor
 *
 * Implicit returns:
 *		*resultfp (modified)		Fileproc pointer
 *
 * Locks:	If the argument 'locked' is non-zero, then the caller is
 *		expected to have taken and held the proc_fdlock; if it is
 *		zero, than this routine internally takes and drops this lock.
 */
int
fp_lookup(proc_t p, int fd, struct fileproc **resultfp, int locked)
{
	struct filedesc *fdp = p->p_fd;
	struct fileproc *fp;

	if (!locked)
		proc_fdlock_spin(p);
	if (fd < 0 || fdp == NULL || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			(fdp->fd_ofileflags[fd] & UF_RESERVED)) {
		if (!locked)
			proc_fdunlock(p);
		return (EBADF);
	}
	fp->f_iocount++;

	if (resultfp)
		*resultfp = fp;
	if (!locked)
		proc_fdunlock(p);
		
	return (0);
}


/*
 * fp_drop_written
 *
 * Description:	Set the FP_WRITTEN flag on the fileproc and drop the I/O
 *		reference previously taken by calling fp_lookup et. al.
 *
 * Parameters:	p				Process in which the fd lives
 *		fd				fd associated with the fileproc
 *		fp				fileproc on which to set the
 *						flag and drop the reference
 *
 * Returns:	0				Success
 *	fp_drop:EBADF				Bad file descriptor
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the supplied process
 *
 * Notes:	The fileproc must correspond to the fd in the supplied proc
 */
int
fp_drop_written(proc_t p, int fd, struct fileproc *fp)
{
        int error;

	proc_fdlock_spin(p);

	fp->f_flags |= FP_WRITTEN;
	
	error = fp_drop(p, fd, fp, 1);

	proc_fdunlock(p);
		
	return (error);
}


/*
 * fp_drop_event
 *
 * Description:	Set the FP_WAITEVENT flag on the fileproc and drop the I/O
 *		reference previously taken by calling fp_lookup et. al.
 *
 * Parameters:	p				Process in which the fd lives
 *		fd				fd associated with the fileproc
 *		fp				fileproc on which to set the
 *						flag and drop the reference
 *
 * Returns:	0				Success
 *	fp_drop:EBADF				Bad file descriptor
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the supplied process
 *
 * Notes:	The fileproc must correspond to the fd in the supplied proc
 */
int
fp_drop_event(proc_t p, int fd, struct fileproc *fp)
{
        int error;

	proc_fdlock_spin(p);

	fp->f_flags |= FP_WAITEVENT;
	
	error = fp_drop(p, fd, fp, 1);

	proc_fdunlock(p);
		
	return (error);
}


/*
 * fp_drop
 *
 * Description:	Drop the I/O reference previously taken by calling fp_lookup
 *		et. al.
 *
 * Parameters:	p				Process in which the fd lives
 *		fd				fd associated with the fileproc
 *		fp				fileproc on which to set the
 *						flag and drop the reference
 *		locked				flag to internally take and
 *						drop proc_fdlock if it is not
 *						already held by the caller
 *
 * Returns:	0				Success
 *		EBADF				Bad file descriptor
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the supplied process if 'locked' is non-zero, and assumes that
 *		the caller already holds this lock if 'locked' is non-zero.
 *
 * Notes:	The fileproc must correspond to the fd in the supplied proc
 */
int
fp_drop(proc_t p, int fd, struct fileproc *fp, int locked)
{
	struct filedesc *fdp = p->p_fd;
	int	needwakeup = 0;

	if (!locked)
		proc_fdlock_spin(p);
	 if ((fp == FILEPROC_NULL) && (fd < 0 || fd >= fdp->fd_nfiles ||
			(fp = fdp->fd_ofiles[fd]) == NULL ||
			((fdp->fd_ofileflags[fd] & UF_RESERVED) &&
			 !(fdp->fd_ofileflags[fd] & UF_CLOSING)))) {
		if (!locked)
			proc_fdunlock(p);
		return (EBADF);
	}
	fp->f_iocount--;

	if (p->p_fpdrainwait && fp->f_iocount == 0) {
	        p->p_fpdrainwait = 0;
		needwakeup = 1;
	}
	if (!locked)
		proc_fdunlock(p);
	if (needwakeup)
	        wakeup(&p->p_fpdrainwait);
		
	return (0);
}


/*
 * file_vnode
 *
 * Description:	Given an fd, look it up in the current process's per process
 *		open file table, and return its internal vnode pointer.
 *
 * Parameters:	fd				fd to obtain vnode from
 *		vpp				pointer to vnode return area
 *
 * Returns:	0				Success
 *		EINVAL				The fd does not refer to a
 *						vnode fileproc entry
 *	fp_lookup:EBADF				Bad file descriptor
 *
 * Implicit returns:
 *		*vpp (modified)			Returned vnode pointer
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the current process
 *
 * Notes:	If successful, this function increments the f_iocount on the
 *		fd's corresponding fileproc.
 *
 *		The fileproc referenced is not returned; because of this, care
 *		must be taken to not drop the last reference (e.g. by closing
 *		the file).  This is inhernely unsafe, since the reference may
 *		not be recoverable from the vnode, if there is a subsequent
 *		close that destroys the associate fileproc.  The caller should
 *		therefore retain their own reference on the fileproc so that
 *		the f_iocount can be dropped subsequently.  Failure to do this
 *		can result in the returned pointer immediately becoming invalid
 *		following the call.
 *
 *		Use of this function is discouraged.
 */
int
file_vnode(int fd, struct vnode **vpp)
{
	proc_t p = current_proc();
	struct fileproc *fp;
	int error;
	
	proc_fdlock_spin(p);
	if ( (error = fp_lookup(p, fd, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	if (fp->f_type != DTYPE_VNODE) {
		fp_drop(p, fd, fp,1);
		proc_fdunlock(p);
		return(EINVAL);
	}
	*vpp = (struct vnode *)fp->f_data;
	proc_fdunlock(p);

	return(0);
}


/*
 * file_socket
 *
 * Description:	Given an fd, look it up in the current process's per process
 *		open file table, and return its internal socket pointer.
 *
 * Parameters:	fd				fd to obtain vnode from
 *		sp				pointer to socket return area
 *
 * Returns:	0				Success
 *		ENOTSOCK			Not a socket
 *		fp_lookup:EBADF			Bad file descriptor
 *
 * Implicit returns:
 *		*sp (modified)			Returned socket pointer
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the current process
 *
 * Notes:	If successful, this function increments the f_iocount on the
 *		fd's corresponding fileproc.
 *
 *		The fileproc referenced is not returned; because of this, care
 *		must be taken to not drop the last reference (e.g. by closing
 *		the file).  This is inhernely unsafe, since the reference may
 *		not be recoverable from the socket, if there is a subsequent
 *		close that destroys the associate fileproc.  The caller should
 *		therefore retain their own reference on the fileproc so that
 *		the f_iocount can be dropped subsequently.  Failure to do this
 *		can result in the returned pointer immediately becoming invalid
 *		following the call.
 *
 *		Use of this function is discouraged.
 */
int
file_socket(int fd, struct socket **sp)
{
	proc_t p = current_proc();
	struct fileproc *fp;
	int error;
	
	proc_fdlock_spin(p);
	if ( (error = fp_lookup(p, fd, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	if (fp->f_type != DTYPE_SOCKET) {
		fp_drop(p, fd, fp,1);
		proc_fdunlock(p);
		return(ENOTSOCK);
	}
	*sp = (struct socket *)fp->f_data;
	proc_fdunlock(p);

	return(0);
}


/*
 * file_flags
 *
 * Description:	Given an fd, look it up in the current process's per process
 *		open file table, and return its fileproc's flags field.
 *
 * Parameters:	fd				fd whose flags are to be
 *						retrieved
 *		flags				pointer to flags data area
 *
 * Returns:	0				Success
 *		ENOTSOCK			Not a socket
 *		fp_lookup:EBADF			Bad file descriptor
 *
 * Implicit returns:
 *		*flags (modified)		Returned flags field
 *
 * Locks:	This function internally takes and drops the proc_fdlock for
 *		the current process
 *
 * Notes:	This function will internally increment and decrement the
 *		f_iocount of the fileproc as part of its operation.
 */
int
file_flags(int fd, int *flags)
{

	proc_t p = current_proc();
	struct fileproc *fp;
	int error;
	
	proc_fdlock_spin(p);
	if ( (error = fp_lookup(p, fd, &fp, 1)) ) {
		proc_fdunlock(p);
		return(error);
	}
	*flags = (int)fp->f_flag;
	fp_drop(p, fd, fp,1);
	proc_fdunlock(p);

	return(0);
}


/*
 * file_drop
 *
 * Description:	Drop an iocount reference on an fd, and wake up any waiters
 *		for draining (i.e. blocked in fileproc_drain() called during
 *		the last attempt to close a file).
 *
 * Parameters:	fd				fd on which an ioreference is
 *						to be dropped
 *
 * Returns:	0				Success
 *		EBADF				Bad file descriptor
 *
 * Description:	Given an fd, look it up in the current process's per process
 *		open file table, and drop it's fileproc's f_iocount by one
 *
 * Notes:	This is intended as a corresponding operation to the functions
 *		file_vnode() and file_socket() operations.
 *
 *		Technically, the close reference is supposed to be protected
 *		by a fileproc_drain(), however, a drain will only block if
 *		the fd refers to a character device, and that device has had
 *		preparefileread() called on it.  If it refers to something
 *		other than a character device, then the drain will occur and
 *		block each close attempt, rather than merely the last close.
 *
 *		Since it's possible for an fd that refers to a character
 *		device to have an intermediate close followed by an open to
 *		cause a different file to correspond to that descriptor,
 *		unless there was a cautionary reference taken on the fileproc,
 *		this is an inherently unsafe function.  This happens in the
 *		case where multiple fd's in a process refer to the same
 *		character device (e.g. stdin/out/err pointing to a tty, etc.).
 *
 *		Use of this function is discouraged.
 */
int 
file_drop(int fd)
{
	struct fileproc *fp;
	proc_t p = current_proc();
	int	needwakeup = 0;

	proc_fdlock_spin(p);
	if (fd < 0 || fd >= p->p_fd->fd_nfiles ||
			(fp = p->p_fd->fd_ofiles[fd]) == NULL ||
			((p->p_fd->fd_ofileflags[fd] & UF_RESERVED) &&
			 !(p->p_fd->fd_ofileflags[fd] & UF_CLOSING))) {
		proc_fdunlock(p);
		return (EBADF);
	}
	fp->f_iocount --;

	if (p->p_fpdrainwait && fp->f_iocount == 0) {
	        p->p_fpdrainwait = 0;
		needwakeup = 1;
	}
	proc_fdunlock(p);

	if (needwakeup)
	        wakeup(&p->p_fpdrainwait);
	return(0);
}


/*
 * falloc
 *
 * Description:	Allocate an entry in the per process open file table and
 *		return the corresponding fileproc and fd.
 *
 * Parameters:	p				The process in whose open file
 *						table the fd is to be allocated
 *		resultfp			Pointer to fileproc pointer
 *						return area
 *		resultfd			Pointer to fd return area
 *		ctx				VFS context
 *
 * Returns:	0				Success
 *	falloc:ENFILE				Too many open files in system
 *	falloc:EMFILE				Too many open files in process
 *	falloc:ENOMEM				M_FILEPROC or M_FILEGLOB zone
 *						exhausted
 *
 * Implicit returns:
 *		*resultfd (modified)		Returned fileproc pointer
 *		*resultfd (modified)		Returned fd
 *
 * Locks:	This function takes and drops the proc_fdlock; if this lock
 *		is alread held, use falloc_locked() instead.
 *
 * Notes:	This function takes separate process and context arguments
 *		solely to support kern_exec.c; otherwise, it would take
 *		neither, and expect falloc_locked() to use the
 *		vfs_context_current() routine internally.
 */
int
falloc(proc_t p, struct fileproc **resultfp, int *resultfd, vfs_context_t ctx)
{
	int error;

	proc_fdlock(p);
	error = falloc_locked(p, resultfp, resultfd, ctx, 1);
	proc_fdunlock(p);

	return(error);
}


/*
 * falloc_locked
 *
 * Create a new open file structure and allocate
 * a file decriptor for the process that refers to it.
 *
 * Returns:	0			Success
 *
 * Description:	Allocate an entry in the per process open file table and
 *		return the corresponding fileproc and fd.
 *
 * Parameters:	p				The process in whose open file
 *						table the fd is to be allocated
 *		resultfp			Pointer to fileproc pointer
 *						return area
 *		resultfd			Pointer to fd return area
 *		ctx				VFS context
 *		locked				Flag to indicate whether the
 *						caller holds proc_fdlock
 *
 * Returns:	0				Success
 *		ENFILE				Too many open files in system
 *		fdalloc:EMFILE			Too many open files in process
 *		ENOMEM				M_FILEPROC or M_FILEGLOB zone
 *						exhausted
 *	fdalloc:ENOMEM
 *
 * Implicit returns:
 *		*resultfd (modified)		Returned fileproc pointer
 *		*resultfd (modified)		Returned fd
 *
 * Locks:	If the parameter 'locked' is zero, this function takes and
 *		drops the proc_fdlock; if non-zero, the caller must hold the
 *		lock.
 *
 * Notes:	If you intend to use a non-zero 'locked' parameter, use the
 *		utility function falloc() instead.
 *
 *		This function takes separate process and context arguments
 *		solely to support kern_exec.c; otherwise, it would take
 *		neither, and use the vfs_context_current() routine internally.
 */
int
falloc_locked(proc_t p, struct fileproc **resultfp, int *resultfd,
	      vfs_context_t ctx, int locked)
{
	struct fileproc *fp, *fq;
	struct fileglob *fg;
	int error, nfd;

	if (!locked)
		proc_fdlock(p);
	if ( (error = fdalloc(p, 0, &nfd)) ) {
		if (!locked)
			proc_fdunlock(p);
		return (error);
	}
	if (nfiles >= maxfiles) {
		if (!locked)
			proc_fdunlock(p);
		tablefull("file");
		return (ENFILE);
	}
#if CONFIG_MACF
	error = mac_file_check_create(proc_ucred(p));
	if (error) {
		if (!locked)
			proc_fdunlock(p);
		return (error);
	}
#endif

	/*
	 * Allocate a new file descriptor.
	 * If the process has file descriptor zero open, add to the list
	 * of open files at that point, otherwise put it at the front of
	 * the list of open files.
	 */
	proc_fdunlock(p);

	MALLOC_ZONE(fp, struct fileproc *, sizeof(struct fileproc), M_FILEPROC, M_WAITOK);
	if (fp == NULL) {
		if (locked)
			proc_fdlock(p);
		return (ENOMEM);
	}
	MALLOC_ZONE(fg, struct fileglob *, sizeof(struct fileglob), M_FILEGLOB, M_WAITOK);
	if (fg == NULL) {
		FREE_ZONE(fp, sizeof(*fp), M_FILEPROC);
		if (locked)
			proc_fdlock(p);
		return (ENOMEM);
	}
	bzero(fp, sizeof(struct fileproc));
	bzero(fg, sizeof(struct fileglob));
	lck_mtx_init(&fg->fg_lock, file_lck_grp, file_lck_attr);

	fp->f_iocount = 1;
	fg->fg_count = 1;
	fp->f_fglob = fg;
#if CONFIG_MACF
	mac_file_label_init(fg);
#endif

	kauth_cred_ref(ctx->vc_ucred);

	proc_fdlock(p);

	fp->f_cred = ctx->vc_ucred;

#if CONFIG_MACF
	mac_file_label_associate(fp->f_cred, fg);
#endif

	lck_mtx_lock_spin(file_flist_lock);

	nfiles++;

	if ( (fq = p->p_fd->fd_ofiles[0]) ) {
		LIST_INSERT_AFTER(fq->f_fglob, fg, f_list);
	} else {
		LIST_INSERT_HEAD(&filehead, fg, f_list);
	}
	lck_mtx_unlock(file_flist_lock);

	p->p_fd->fd_ofiles[nfd] = fp;

	if (!locked)
		proc_fdunlock(p);

	if (resultfp)
		*resultfp = fp;
	if (resultfd)
		*resultfd = nfd;

	return (0);
}


/*
 * fg_free
 *
 * Description:	Free a file structure; drop the global open file count, and
 *		drop the credential reference, if the fileglob has one, and
 *		destroy the instance mutex before freeing
 *
 * Parameters:	fg				Pointer to fileglob to be
 *						freed
 *
 * Returns:	void
 */
void
fg_free(struct fileglob *fg)
{
	lck_mtx_lock_spin(file_flist_lock);
	LIST_REMOVE(fg, f_list);
	nfiles--;
	lck_mtx_unlock(file_flist_lock);

	if (IS_VALID_CRED(fg->fg_cred)) {
		kauth_cred_unref(&fg->fg_cred);
	}
	lck_mtx_destroy(&fg->fg_lock, file_lck_grp);

#if CONFIG_MACF
	mac_file_label_destroy(fg);
#endif
	FREE_ZONE(fg, sizeof *fg, M_FILEGLOB);
}


/*
 * fdexec
 *
 * Description:	Perform close-on-exec processing for all files in a process
 *		that are either marked as close-on-exec, or which were in the
 *		process of being opened at the time of the execve
 *
 * Parameters:	p				Pointer to process calling
 *						execve
 *
 * Returns:	void
 *
 * Locks:	This function internally takes and drops proc_fdlock()
 *
 * Notes:	This function drops and retakes the kernel funnel; this is
 *		inherently unsafe, since another thread may have the
 *		proc_fdlock.
 *
 * XXX:		We should likely reverse the lock and funnel drop/acquire
 *		order to avoid the small race window; it's also possible that
 *		if the program doing the exec has an outstanding listen socket
 *		and a network connection is completed asyncrhonously that we
 *		will end up with a "ghost" socket reference in the new process.
 *
 *		This needs reworking to make it safe to remove the funnel from
 *		the execve and posix_spawn system calls.
 */
void
fdexec(proc_t p)
{
	struct filedesc *fdp = p->p_fd;
	int i = fdp->fd_lastfile;
	struct fileproc *fp;

	proc_fdlock(p);
	while (i >= 0) {

		fp = fdp->fd_ofiles[i];
		if (
		    ((fdp->fd_ofileflags[i] & (UF_RESERVED|UF_EXCLOSE)) == UF_EXCLOSE)
#if CONFIG_MACF
		    || (fp && mac_file_check_inherit(proc_ucred(p), fp->f_fglob))
#endif
		) {
                        if (i < fdp->fd_knlistsize)
                                knote_fdclose(p, i);
			procfdtbl_clearfd(p, i);
			if (i == fdp->fd_lastfile && i > 0)
				fdp->fd_lastfile--;
			if (i < fdp->fd_freefile)
				fdp->fd_freefile = i;
			closef_locked(fp, fp->f_fglob, p);
			FREE_ZONE(fp, sizeof(*fp), M_FILEPROC);
		}
		i--;
	}
	proc_fdunlock(p);
}


/*
 * fdcopy
 *
 * Description:	Copy a filedesc structure.  This is normally used as part of
 *		forkproc() when forking a new process, to copy the per process
 *		open file table over to the new process.
 *
 * Parameters:	p				Process whose open file table
 *						is to be copied (parent)
 *		uth_cdir			Per thread current working
 *						cirectory, or NULL
 *
 * Returns:	NULL				Copy failed
 *		!NULL				Pointer to new struct filedesc
 *
 * Locks:	This function internally takes and drops proc_fdlock()
 *
 * Notes:	Files are copied directly, ignoring the new resource limits
 *		for the process that's being copied into.  Since the descriptor
 *		references are just additional references, this does not count
 *		against the number of open files on the system.
 *
 *		The struct filedesc includes the current working directory,
 *		and the current root directory, if the process is chroot'ed.
 *
 *		If the exec was called by a thread using a per thread current
 *		working directory, we inherit the working directory from the
 *		thread making the call, rather than from the process.
 *
 *		In the case of a failure to obtain a reference, for most cases,
 *		the file entry will be silently droppped.  There's an exception
 *		for the case of a chroot dir, since a failure to to obtain a
 *		reference there would constitute an "escape" from the chroot
 *		environment, which must not be allowed.  In that case, we will
 *		deny the execve() operation, rather than allowing the escape.
 */
struct filedesc *
fdcopy(proc_t p, vnode_t uth_cdir)
{
	struct filedesc *newfdp, *fdp = p->p_fd;
	int i;
	struct fileproc *ofp, *fp;
	vnode_t	v_dir;

	MALLOC_ZONE(newfdp, struct filedesc *,
			sizeof(*newfdp), M_FILEDESC, M_WAITOK);
	if (newfdp == NULL)
		return(NULL);

	proc_fdlock(p);

	/*
	 * the FD_CHROOT flag will be inherited via this copy
	 */
	(void) memcpy(newfdp, fdp, sizeof(*newfdp));

	/*
	 * If we are running with per-thread current working directories,
	 * inherit the new current working directory from the current thread
	 * instead, before we take our references.
	 */
	if (uth_cdir != NULLVP)
		newfdp->fd_cdir = uth_cdir;

	/*
	 * For both fd_cdir and fd_rdir make sure we get
	 * a valid reference... if we can't, than set
	 * set the pointer(s) to NULL in the child... this
	 * will keep us from using a non-referenced vp
	 * and allows us to do the vnode_rele only on
	 * a properly referenced vp
	 */
	if ( (v_dir = newfdp->fd_cdir) ) {
	        if (vnode_getwithref(v_dir) == 0) {
		        if ( (vnode_ref(v_dir)) )
			        newfdp->fd_cdir = NULL;
			vnode_put(v_dir);
		} else
		        newfdp->fd_cdir = NULL;
	}
	if (newfdp->fd_cdir == NULL && fdp->fd_cdir) {
	        /*
		 * we couldn't get a new reference on
		 * the current working directory being
		 * inherited... we might as well drop
		 * our reference from the parent also
		 * since the vnode has gone DEAD making
		 * it useless... by dropping it we'll
		 * be that much closer to recyling it
		 */
	        vnode_rele(fdp->fd_cdir);
		fdp->fd_cdir = NULL;
	}

	if ( (v_dir = newfdp->fd_rdir) ) {
		if (vnode_getwithref(v_dir) == 0) {
			if ( (vnode_ref(v_dir)) )
			        newfdp->fd_rdir = NULL;
			vnode_put(v_dir);
		} else {
		        newfdp->fd_rdir = NULL;
		}
	}
	/* Coming from a chroot environment and unable to get a reference... */
	if (newfdp->fd_rdir == NULL && fdp->fd_rdir) {
	        /*
		 * We couldn't get a new reference on
		 * the chroot directory being
		 * inherited... this is fatal, since
		 * otherwise it would constitute an
		 * escape from a chroot environment by
		 * the new process.
		 */
		if (newfdp->fd_cdir)
		        vnode_rele(newfdp->fd_cdir);
		FREE_ZONE(newfdp, sizeof *newfdp, M_FILEDESC);
		return(NULL);
	}
	newfdp->fd_refcnt = 1;

	/*
	 * If the number of open files fits in the internal arrays
	 * of the open file structure, use them, otherwise allocate
	 * additional memory for the number of descriptors currently
	 * in use.
	 */
	if (newfdp->fd_lastfile < NDFILE)
		i = NDFILE;
	else {
		/*
		 * Compute the smallest multiple of NDEXTENT needed
		 * for the file descriptors currently in use,
		 * allowing the table to shrink.
		 */
		i = newfdp->fd_nfiles;
		while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2)
			i /= 2;
	}
	proc_fdunlock(p);

	MALLOC_ZONE(newfdp->fd_ofiles, struct fileproc **,
				i * OFILESIZE, M_OFILETABL, M_WAITOK);
	if (newfdp->fd_ofiles == NULL) {
		if (newfdp->fd_cdir)
		        vnode_rele(newfdp->fd_cdir);
		if (newfdp->fd_rdir)
			vnode_rele(newfdp->fd_rdir);

		FREE_ZONE(newfdp, sizeof(*newfdp), M_FILEDESC);
		return(NULL);
	}
	(void) memset(newfdp->fd_ofiles, 0, i * OFILESIZE);
	proc_fdlock(p);

	newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i];
	newfdp->fd_nfiles = i;

	if (fdp->fd_nfiles > 0) {
		struct fileproc **fpp;
		char *flags;

		(void) memcpy(newfdp->fd_ofiles, fdp->fd_ofiles,
					(newfdp->fd_lastfile + 1) * sizeof(*fdp->fd_ofiles));
		(void) memcpy(newfdp->fd_ofileflags, fdp->fd_ofileflags,
					(newfdp->fd_lastfile + 1) * sizeof(*fdp->fd_ofileflags));

		/*
		 * kq descriptors cannot be copied.
		 */
		if (newfdp->fd_knlistsize != -1) {
			fpp = &newfdp->fd_ofiles[newfdp->fd_lastfile];
			for (i = newfdp->fd_lastfile; i >= 0; i--, fpp--) {
				if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE) {
					*fpp = NULL;
					if (i < newfdp->fd_freefile)
						newfdp->fd_freefile = i;
				}
				if (*fpp == NULL && i == newfdp->fd_lastfile && i > 0)
					newfdp->fd_lastfile--;
			}
			newfdp->fd_knlist = NULL;
			newfdp->fd_knlistsize = -1;
			newfdp->fd_knhash = NULL;
			newfdp->fd_knhashmask = 0;
		}
		fpp = newfdp->fd_ofiles;
		flags = newfdp->fd_ofileflags;

		for (i = newfdp->fd_lastfile + 1; --i >= 0; fpp++, flags++)
			if ((ofp = *fpp) != NULL && !(*flags & UF_RESERVED)) {
				MALLOC_ZONE(fp, struct fileproc *, sizeof(struct fileproc), M_FILEPROC, M_WAITOK);
				if (fp == NULL) {
					/*
					 * XXX no room to copy, unable to
					 * XXX safely unwind state at present
					 */
					*fpp = NULL;
				} else {
					bzero(fp, sizeof(struct fileproc));
					fp->f_flags = ofp->f_flags;
					//fp->f_iocount = ofp->f_iocount;
					fp->f_iocount = 0;
					fp->f_fglob = ofp->f_fglob;
					(void)fg_ref(fp);
					*fpp = fp;
				}
			} else {
				if (i < newfdp->fd_freefile)
					newfdp->fd_freefile = i;
				*fpp = NULL;
				*flags = 0;
			}
	}

	proc_fdunlock(p);
	return (newfdp);
}


/*
 * fdfree
 *
 * Description:	Release a filedesc (per process open file table) structure;
 *		this is done on process exit(), or from forkproc_free() if
 *		the fork fails for some reason subsequent to a successful
 *		call to fdcopy()
 *
 * Parameters:	p				Pointer to process going away
 *
 * Returns:	void
 *
 * Locks:	This function internally takes and drops proc_fdlock()
 */
void
fdfree(proc_t p)
{
	struct filedesc *fdp;
	struct fileproc *fp;
	int i;

	proc_fdlock(p);

	/* Certain daemons might not have file descriptors */
	fdp = p->p_fd;

	if ((fdp == NULL) || (--fdp->fd_refcnt > 0)) {
	        proc_fdunlock(p);
		return;
	}
	if (fdp->fd_refcnt == 0xffff)
	        panic("fdfree: bad fd_refcnt");

	/* Last reference: the structure can't change out from under us */

	if (fdp->fd_nfiles > 0 && fdp->fd_ofiles) {
	        for (i = fdp->fd_lastfile; i >= 0; i--) {
			if ((fp = fdp->fd_ofiles[i]) != NULL) {
			  
			  if (fdp->fd_ofileflags[i] & UF_RESERVED)
			    	panic("fdfree: found fp with UF_RESERVED\n");

				/* closef drops the iocount ... */
				if ((fp->f_flags & FP_INCHRREAD) != 0) 
					fp->f_iocount++;
				procfdtbl_reservefd(p, i);

				if (i < fdp->fd_knlistsize)
					knote_fdclose(p, i);
				if (fp->f_flags & FP_WAITEVENT) 
					(void)waitevent_close(p, fp);
				(void) closef_locked(fp, fp->f_fglob, p);
				FREE_ZONE(fp, sizeof(*fp), M_FILEPROC);
			}
		}
		FREE_ZONE(fdp->fd_ofiles, fdp->fd_nfiles * OFILESIZE, M_OFILETABL);
		fdp->fd_ofiles = NULL;
		fdp->fd_nfiles = 0;
	}        

	proc_fdunlock(p);
	
	if (fdp->fd_cdir)
	        vnode_rele(fdp->fd_cdir);
	if (fdp->fd_rdir)
		vnode_rele(fdp->fd_rdir);

	proc_fdlock_spin(p);
	p->p_fd = NULL;
	proc_fdunlock(p);

	if (fdp->fd_knlist)
		FREE(fdp->fd_knlist, M_KQUEUE);
	if (fdp->fd_knhash)
		FREE(fdp->fd_knhash, M_KQUEUE);

	FREE_ZONE(fdp, sizeof(*fdp), M_FILEDESC);
}


/*
 * closef_finish
 *
 * Description:	Called on last open instance for a fileglob for a file being
 *		closed.
 *
 * Parameters:	fp			Pointer to fileproc for fd
 *		fg			Pointer to fileglob for fd
 *		p			Pointer to proc structure
 *
 * Returns:	0			Success
 *	<fo_close>:???			Anything returnable by a per-fileops
 *					close function
 *
 * Note:	fp can only be non-NULL if p is also non-NULL.  If p is NULL,
 *		then fg must eith be locked (FHASLOCK) or must not have a
 *		type of DTYPE_VNODE.
 *
 *		On return, the fg is freed.
 *
 *		This function may block draining output to a character
 *		device on last close of that device.
 */
static int
closef_finish(struct fileproc *fp, struct fileglob *fg, proc_t p, vfs_context_t ctx)
{
	int error;


	/* fg_ops completed initialization? */
	if (fg->fg_ops)
		error = fo_close(fg, ctx);
	else
		error = 0;

	/* if fp is non-NULL, drain it out */
	if (((fp != (struct fileproc *)0) && ((fp->f_flags & FP_INCHRREAD) != 0))) {
	        proc_fdlock_spin(p);
		if ( ((fp->f_flags & FP_INCHRREAD) != 0) ) {
		        fileproc_drain(p, fp);
		}
		proc_fdunlock(p);
	}
	fg_free(fg);

	return (error);
}

/*
 * closef_locked
 *
 * Description:	Internal form of closef; called with proc_fdlock held
 *
 * Parameters:	fp			Pointer to fileproc for fd
 *		fg			Pointer to fileglob for fd
 *		p			Pointer to proc structure
 *
 * Returns:	0			Success
 *	closef_finish:??? 		Anything returnable by a per-fileops
 *					close function
 *
 * Note:	Decrements reference count on file structure; if this was the
 *		last reference, then closef_finish() is called
 *
 *		p and fp are allowed to  be NULL when closing a file that was
 *		being passed in a message (but only if we are called when this
 *		is NOT the last reference).
 */
int
closef_locked(struct fileproc *fp, struct fileglob *fg, proc_t p)
{
	struct vnode *vp;
	struct flock lf;
	struct vfs_context context;
	int error;

	if (fg == NULL) {
		return (0);
	}

	/* Set up context with cred stashed in fg */
	if (p == current_proc())
		context.vc_thread = current_thread();
	else
		context.vc_thread = NULL;
	context.vc_ucred = fg->fg_cred;

	/*
	 * POSIX record locking dictates that any close releases ALL
	 * locks owned by this process.  This is handled by setting
	 * a flag in the unlock to free ONLY locks obeying POSIX
	 * semantics, and not to free BSD-style file locks.
	 * If the descriptor was in a message, POSIX-style locks
	 * aren't passed with the descriptor.
	 */
	if (p && (p->p_ladvflag & P_LADVLOCK) && fg->fg_type == DTYPE_VNODE) {
		proc_fdunlock(p);

		lf.l_whence = SEEK_SET;
		lf.l_start = 0;
		lf.l_len = 0;
		lf.l_type = F_UNLCK;
		vp = (struct vnode *)fg->fg_data;

		if ( (error = vnode_getwithref(vp)) == 0 ) {
			(void) VNOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX, &context);
			(void)vnode_put(vp);
		}
		proc_fdlock(p);
	}
	lck_mtx_lock_spin(&fg->fg_lock);
	fg->fg_count--;

	if (fg->fg_count > 0) {
		lck_mtx_unlock(&fg->fg_lock);
		return (0);
	}
#if DIAGNOSTIC
	if (fg->fg_count != 0)
		panic("fg %p: being freed with bad fg_count (%d)", fg, fg->fg_count);
#endif

	if (fp && (fp->f_flags & FP_WRITTEN))
	        fg->fg_flag |= FWASWRITTEN;

	fg->fg_lflags |= FG_TERM;
	lck_mtx_unlock(&fg->fg_lock);

	proc_fdunlock(p);
	error = closef_finish(fp, fg, p, &context);
	proc_fdlock(p);

	return(error);
}


/* sleep address to permit wakeup of select by fileproc_drain() */
extern int selwait;


/*
 * fileproc_drain
 *
 * Description:	Drain out pending I/O operations
 *
 * Parameters:	p				Process closing this file
 *		fp				fileproc struct for the open
 *						instance on the file
 *
 * Returns:	void
 *
 * Locks:	Assumes the caller holds the proc_fdlock
 *
 * Notes:	For character devices, this occurs on the last close of the
 *		device; for all other file descriptos, this occurs on each
 *		close to prevent fd's from being closed out from under
 *		operations currently in progress and blocked
 *
 * See Also: 	file_vnode(), file_socket(), file_drop(), and the cautions
 *		regarding their use and interaction with this function.
 */
void
fileproc_drain(proc_t p, struct fileproc * fp)
{
	struct vfs_context context;

	context.vc_thread = proc_thread(p);	/* XXX */
	context.vc_ucred = fp->f_fglob->fg_cred;

	fp->f_iocount-- ; /* (the one the close holds) */

	while (fp->f_iocount) {

	        lck_mtx_convert_spin(&p->p_fdmlock);

		if (fp->f_fglob->fg_ops->fo_drain) {
			(*fp->f_fglob->fg_ops->fo_drain)(fp, &context);
		}
		if (((fp->f_flags & FP_INSELECT)== FP_INSELECT)) {
			wait_queue_wakeup_all((wait_queue_t)fp->f_waddr, &selwait, THREAD_INTERRUPTED);
		} 
		p->p_fpdrainwait = 1;

		msleep(&p->p_fpdrainwait, &p->p_fdmlock, PRIBIO, "fpdrain", NULL);

	}
}


/*
 * fp_free
 *
 * Description:	Release the fd and free the fileproc associated with the fd
 *		in the per process open file table of the specified process;
 *		these values must correspond.
 *
 * Parameters:	p				Process containing fd
 *		fd				fd to be released
 *		fp				fileproc to be freed
 *
 * Returns:	0				Success
 *
 * Notes:	XXX function should be void - no one interprets the returns
 *		XXX code
 */
int
fp_free(proc_t p, int fd, struct fileproc * fp)
{
        proc_fdlock_spin(p);
	fdrelse(p, fd);
        proc_fdunlock(p);

	fg_free(fp->f_fglob);
	FREE_ZONE(fp, sizeof(*fp), M_FILEPROC);
	return(0);
}


/*
 * flock
 *
 * Description:	Apply an advisory lock on a file descriptor.
 *
 * Parameters:	p				Process making request
 *		uap->fd				fd on which the lock is to be
 *						attempted
 *		uap->how			(Un)Lock bits, including type
 *		retval				Pointer to the call return area
 *		
 * Returns:	0				Success
 *	fp_getfvp:EBADF				Bad file descriptor
 *	fp_getfvp:ENOTSUP			fd does not refer to a vnode
 *	vnode_getwithref:???
 *	VNOP_ADVLOCK:???
 *
 * Implicit returns:
 *		*retval (modified)		Size of dtable
 *
 * Notes:	Just attempt to get a record lock of the requested type on
 *		the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
 */
int
flock(proc_t p, struct flock_args *uap, __unused register_t *retval)
{
	int fd = uap->fd;
	int how = uap->how;
	struct fileproc *fp;
	struct vnode *vp;
	struct flock lf;
	vfs_context_t ctx = vfs_context_current();
	int error=0;

	AUDIT_ARG(fd, uap->fd);
	if ( (error = fp_getfvp(p, fd, &fp, &vp)) ) {
		return(error);
	}
	if ( (error = vnode_getwithref(vp)) ) {
		goto out1;
	}
	AUDIT_ARG(vnpath, vp, ARG_VNODE1);

	lf.l_whence = SEEK_SET;
	lf.l_start = 0;
	lf.l_len = 0;
	if (how & LOCK_UN) {
		lf.l_type = F_UNLCK;
		fp->f_flag &= ~FHASLOCK;
		error = VNOP_ADVLOCK(vp, (caddr_t)fp->f_fglob, F_UNLCK, &lf, F_FLOCK, ctx);
		goto out;
	}
	if (how & LOCK_EX)
		lf.l_type = F_WRLCK;
	else if (how & LOCK_SH)
		lf.l_type = F_RDLCK;
	else {
	        error = EBADF;
		goto out;
	}
#if CONFIG_MACF
	error = mac_file_check_lock(proc_ucred(p), fp->f_fglob, F_SETLK, &lf);
	if (error)
		goto out;
#endif
	fp->f_flag |= FHASLOCK;
	if (how & LOCK_NB) {
		error = VNOP_ADVLOCK(vp, (caddr_t)fp->f_fglob, F_SETLK, &lf, F_FLOCK, ctx);
		goto out;	
	}
	error = VNOP_ADVLOCK(vp, (caddr_t)fp->f_fglob, F_SETLK, &lf, F_FLOCK|F_WAIT, ctx);
out:
	(void)vnode_put(vp);
out1:
	fp_drop(p, fd, fp, 0);
	return(error);

}

/*
 * dupfdopen
 *
 * Description:	Duplicate the specified descriptor to a free descriptor;
 *		this is the second half of fdopen(), above.
 *
 * Parameters:	fdp				filedesc pointer to fill in
 *		indx				fd to dup to
 *		dfd				fd to dup from
 *		mode				mode to set on new fd
 *		error				command code
 *
 * Returns:	0				Success
 *		EBADF				Source fd is bad
 *		EACCES				Requested mode not allowed
 *		!0				'error', if not ENODEV or
 *						ENXIO
 *
 * Notes:	XXX This is not thread safe; see fdopen() above
 */
int
dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode, int error)
{
	struct fileproc *wfp;
	struct fileproc *fp;
#if CONFIG_MACF
	int myerror;
#endif
	proc_t p = current_proc();

	/*
	 * If the to-be-dup'd fd number is greater than the allowed number
	 * of file descriptors, or the fd to be dup'd has already been
	 * closed, reject.  Note, check for new == old is necessary as
	 * falloc could allocate an already closed to-be-dup'd descriptor
	 * as the new descriptor.
	 */
	proc_fdlock(p);

	fp = fdp->fd_ofiles[indx];
	if (dfd < 0 || dfd >= fdp->fd_nfiles ||
			(wfp = fdp->fd_ofiles[dfd]) == NULL || wfp == fp ||
	                (fdp->fd_ofileflags[dfd] & UF_RESERVED)) {

	        proc_fdunlock(p);
		return (EBADF);
	}
#if CONFIG_MACF
	myerror = mac_file_check_dup(proc_ucred(p), wfp->f_fglob, dfd);
	if (myerror) {
		proc_fdunlock(p);
		return (myerror);
	}
#endif
	/*
	 * There are two cases of interest here.
	 *
	 * For ENODEV simply dup (dfd) to file descriptor
	 * (indx) and return.
	 *
	 * For ENXIO steal away the file structure from (dfd) and
	 * store it in (indx).  (dfd) is effectively closed by
	 * this operation.
	 *
	 * Any other error code is just returned.
	 */
	switch (error) {
	case ENODEV:
		/*
		 * Check that the mode the file is being opened for is a
		 * subset of the mode of the existing descriptor.
		 */
	        if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
		        proc_fdunlock(p);
			return (EACCES);
		}
		if (indx > fdp->fd_lastfile)
			fdp->fd_lastfile = indx;
		(void)fg_ref(wfp);

		if (fp->f_fglob)
		        fg_free(fp->f_fglob);
		fp->f_fglob = wfp->f_fglob;

		fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];

	        proc_fdunlock(p);
		return (0);

	default:
	        proc_fdunlock(p);
		return (error);
	}
	/* NOTREACHED */
}


/*
 * fg_ref
 *
 * Description:	Add a reference to a fileglob by fileproc
 *
 * Parameters:	fp				fileproc containing fileglob
 *						pointer
 *
 * Returns:	void
 *
 * Notes:	XXX Should use OSAddAtomic?
 */
void
fg_ref(struct fileproc * fp)
{
	struct fileglob *fg;

	fg = fp->f_fglob;

	lck_mtx_lock_spin(&fg->fg_lock);

#if DIAGNOSTIC
	if ((fp->f_flags & ~((unsigned int)FP_VALID_FLAGS)) != 0)
		panic("fg_ref: invalid bits on fp%x\n", (unsigned int)fp);

	if (fg->fg_count == 0)
		panic("fg_ref: adding fgcount to zeroed fg :fp %x, fg%x\n ", (unsigned int)fp, (unsigned int)fg);
#endif
	fg->fg_count++;
	lck_mtx_unlock(&fg->fg_lock);
}


/*
 * fg_drop
 *
 * Description:	Remove a reference to a fileglob by fileproc
 *
 * Parameters:	fp				fileproc containing fileglob
 *						pointer
 *
 * Returns:	void
 *
 * Notes:	XXX Should use OSAddAtomic?
 */
void
fg_drop(struct fileproc * fp)
{
	struct fileglob *fg;

	fg = fp->f_fglob;
	lck_mtx_lock_spin(&fg->fg_lock);
	fg->fg_count--;
	lck_mtx_unlock(&fg->fg_lock);
}


/*
 * fg_insertuipc
 *
 * Description:	Insert fileglob onto message queue
 *
 * Parameters:	fg				Fileglob pointer to insert
 *
 * Returns:	void
 *
 * Locks:	Takes and drops fg_lock, potentially many times
 */
void
fg_insertuipc(struct fileglob * fg)
{
	int insertque = 0;

	lck_mtx_lock_spin(&fg->fg_lock);

	while (fg->fg_lflags & FG_RMMSGQ) {
		lck_mtx_convert_spin(&fg->fg_lock);

		fg->fg_lflags |= FG_WRMMSGQ;
		msleep(&fg->fg_lflags, &fg->fg_lock, 0, "fg_insertuipc", NULL);
	}

	fg->fg_count++;
	fg->fg_msgcount++;
	if (fg->fg_msgcount == 1) {
		fg->fg_lflags |= FG_INSMSGQ;
		insertque=1;
	}
	lck_mtx_unlock(&fg->fg_lock);

	if (insertque) {
		lck_mtx_lock_spin(uipc_lock);
		unp_gc_wait();
		LIST_INSERT_HEAD(&fmsghead, fg, f_msglist);
		lck_mtx_unlock(uipc_lock);
		lck_mtx_lock(&fg->fg_lock);
		fg->fg_lflags &= ~FG_INSMSGQ;
		if (fg->fg_lflags & FG_WINSMSGQ) {
			fg->fg_lflags &= ~FG_WINSMSGQ;
			wakeup(&fg->fg_lflags);
		}
		lck_mtx_unlock(&fg->fg_lock);
	}

}


/*
 * fg_removeuipc
 *
 * Description:	Remove fileglob from message queue
 *
 * Parameters:	fg				Fileglob pointer to remove
 *
 * Returns:	void
 *
 * Locks:	Takes and drops fg_lock, potentially many times
 */
void
fg_removeuipc(struct fileglob * fg)
{
	int removeque = 0;

	lck_mtx_lock_spin(&fg->fg_lock);
	while (fg->fg_lflags & FG_INSMSGQ) {
		lck_mtx_convert_spin(&fg->fg_lock);

		fg->fg_lflags |= FG_WINSMSGQ;
		msleep(&fg->fg_lflags, &fg->fg_lock, 0, "fg_removeuipc", NULL);
	}
	fg->fg_msgcount--;
	if (fg->fg_msgcount == 0) {
		fg->fg_lflags |= FG_RMMSGQ;
		removeque=1;
	}
	lck_mtx_unlock(&fg->fg_lock);

	if (removeque) {
		lck_mtx_lock_spin(uipc_lock);
		unp_gc_wait();
		LIST_REMOVE(fg, f_msglist);
		lck_mtx_unlock(uipc_lock);
		lck_mtx_lock(&fg->fg_lock);
		fg->fg_lflags &= ~FG_RMMSGQ;
		if (fg->fg_lflags & FG_WRMMSGQ) {
			fg->fg_lflags &= ~FG_WRMMSGQ;
			wakeup(&fg->fg_lflags);
		}
		lck_mtx_unlock(&fg->fg_lock);
	}
}


/*
 * fo_read
 *
 * Description:	Generic fileops read indirected through the fileops pointer
 *		in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer
 *		uio				user I/O structure pointer
 *		flags				FOF_ flags
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from read
 */
int
fo_read(struct fileproc *fp, struct uio *uio, int flags, vfs_context_t ctx)
{
	return ((*fp->f_ops->fo_read)(fp, uio, flags, ctx));
}


/*
 * fo_write
 *
 * Description:	Generic fileops write indirected through the fileops pointer
 *		in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer
 *		uio				user I/O structure pointer
 *		flags				FOF_ flags
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from write
 */
int
fo_write(struct fileproc *fp, struct uio *uio, int flags, vfs_context_t ctx)
{
	return((*fp->f_ops->fo_write)(fp, uio, flags, ctx));
}


/*
 * fo_ioctl
 *
 * Description:	Generic fileops ioctl indirected through the fileops pointer
 *		in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer
 *		com				ioctl command
 *		data				pointer to internalized copy
 *						of user space ioctl command
 *						parameter data in kernel space
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from ioctl
 *
 * Locks:	The caller is assumed to have held the proc_fdlock; this
 *		function releases and reacquires this lock.  If the caller
 *		accesses data protected by this lock prior to calling this
 *		function, it will need to revalidate/reacquire any cached
 *		protected data obtained prior to the call.
 */
int 
fo_ioctl(struct fileproc *fp, u_long com, caddr_t data, vfs_context_t ctx)
{
	int error;

	proc_fdunlock(vfs_context_proc(ctx));
	error = (*fp->f_ops->fo_ioctl)(fp, com, data, ctx);
	proc_fdlock(vfs_context_proc(ctx));
	return(error);
}       


/*
 * fo_select
 *
 * Description:	Generic fileops select indirected through the fileops pointer
 *		in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer
 *		which				select which
 *		wql				pointer to wait queue list
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from select
 */
int
fo_select(struct fileproc *fp, int which, void *wql, vfs_context_t ctx)
{       
	return((*fp->f_ops->fo_select)(fp, which, wql, ctx));
}


/*
 * fo_close
 *
 * Description:	Generic fileops close indirected through the fileops pointer
 *		in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer for
 *						file to close
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from close
 */
int
fo_close(struct fileglob *fg, vfs_context_t ctx)
{       
	return((*fg->fg_ops->fo_close)(fg, ctx));
}


/*
 * fo_kqfilter
 *
 * Description:	Generic fileops kqueue filter indirected through the fileops
 *		pointer in the fileproc structure
 *
 * Parameters:	fp				fileproc structure pointer
 *		kn				pointer to knote to filter on
 *		ctx				VFS context for operation
 *
 * Returns:	0				Success
 *		!0				Errno from kqueue filter
 */
int
fo_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx)
{
        return ((*fp->f_ops->fo_kqfilter)(fp, kn, ctx));
}