FreeBSD/Linux Kernel Cross Reference
sys/bsd/kern/kern_descrip.c

     /*
      * Copyright (c) 2000-2016 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/guarded.h>
    #include <sys/priv.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/stat.h>
    #include <sys/ioctl.h>
    #include <sys/fcntl.h>
    #include <sys/fsctl.h>
    #include <sys/malloc.h>
    #include <sys/mman.h>
    #include <sys/mount.h>
    #include <sys/syslog.h>
    #include <sys/unistd.h>
    #include <sys/resourcevar.h>
    #include <sys/aio_kern.h>
    #include <sys/ev.h>
    #include <kern/locks.h>
   #include <sys/uio_internal.h>
   #include <sys/codesign.h>
   #include <sys/codedir_internal.h>
   #include <sys/mount_internal.h>
   #include <sys/kdebug.h>
   #include <sys/sysproto.h>
   #include <sys/pipe.h>
   #include <sys/spawn.h>
   #include <sys/cprotect.h>
   #include <sys/ubc_internal.h>
   
   #include <kern/kern_types.h>
   #include <kern/kalloc.h>
   #include <kern/waitq.h>
   #include <kern/ipc_misc.h>
   #include <kern/ast.h>
   
   #include <vm/vm_protos.h>
   #include <mach/mach_port.h>
   
   #include <security/audit/audit.h>
   #if CONFIG_MACF
   #include <security/mac_framework.h>
   #endif
   
   #include <stdbool.h>
   #include <os/atomic_private.h>
   #include <os/overflow.h>
   #include <IOKit/IOBSD.h>
   
   #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
   kern_return_t ipc_object_copyin(ipc_space_t, mach_port_name_t,
       mach_msg_type_name_t, ipc_port_t *, mach_port_context_t, mach_msg_guard_flags_t *, uint32_t);
   void ipc_port_release_send(ipc_port_t);
   
   void fileport_releasefg(struct fileglob *fg);
   
   /* flags for fp_close_and_unlock */
   #define FD_DUP2RESV 1
   
   /* We don't want these exported */
   
   __private_extern__
   int unlink1(vfs_context_t, vnode_t, user_addr_t, enum uio_seg, int);
   
   /* Conflict wait queue for when selects collide (opaque type) */
   extern struct waitq select_conflict_queue;
   
   #define f_flag fp_glob->fg_flag
   #define f_type fp_glob->fg_ops->fo_type
   #define f_cred fp_glob->fg_cred
   #define f_ops fp_glob->fg_ops
   #define f_offset fp_glob->fg_offset
   
   ZONE_DEFINE_TYPE(fg_zone, "fileglob", struct fileglob, ZC_ZFREE_CLEARMEM);
   ZONE_DEFINE_ID(ZONE_ID_FILEPROC, "fileproc", struct fileproc, ZC_ZFREE_CLEARMEM);
   
   /*
    * If you need accounting for KM_OFILETABL consider using
    * KALLOC_HEAP_DEFINE to define a view.
    */
   #define KM_OFILETABL KHEAP_DEFAULT
   
   /*
    * rdar://88960128
    */
   #define fd_alloc_files(n_files, flags)                       \
           __typed_allocators_ignore_push                        \
           kheap_alloc(KM_OFILETABL, n_files * OFILESIZE, flags) \
           __typed_allocators_ignore_pop
   
   #define fd_free_files(files, n_files)                        \
           __typed_allocators_ignore_push                        \
           kheap_free(KM_OFILETABL, ofiles, n_files * OFILESIZE) \
           __typed_allocators_ignore_pop
   
   /*
    * Descriptor management.
    */
   int nfiles;                     /* actual number of open files */
   /*
    * "uninitialized" ops -- ensure FILEGLOB_DTYPE(fg) always exists
    */
   static const struct fileops uninitops;
   
   os_refgrp_decl(, f_refgrp, "files refcounts", NULL);
   static LCK_GRP_DECLARE(file_lck_grp, "file");
   
   
   #pragma mark fileglobs
   
   /*!
    * @function fg_free
    *
    * @brief
    * Free a file structure.
    */
   static void
   fg_free(struct fileglob *fg)
   {
           os_atomic_dec(&nfiles, relaxed);
   
           if (fg->fg_vn_data) {
                   fg_vn_data_free(fg->fg_vn_data);
                   fg->fg_vn_data = NULL;
           }
   
           kauth_cred_t cred = fg->fg_cred;
           if (IS_VALID_CRED(cred)) {
                   kauth_cred_unref(&cred);
                   fg->fg_cred = NOCRED;
           }
           lck_mtx_destroy(&fg->fg_lock, &file_lck_grp);
   
   #if CONFIG_MACF && CONFIG_VNGUARD
           vng_file_label_destroy(fg);
   #endif
           zfree(fg_zone, fg);
   }
   
   OS_ALWAYS_INLINE
   void
   fg_ref(proc_t p, struct fileglob *fg)
   {
   #if DEBUG || DEVELOPMENT
           proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
   #else
           (void)p;
   #endif
           os_ref_retain_raw(&fg->fg_count, &f_refgrp);
   }
   
   void
   fg_drop_live(struct fileglob *fg)
   {
           os_ref_release_live_raw(&fg->fg_count, &f_refgrp);
   }
   
   int
   fg_drop(proc_t p, struct fileglob *fg)
   {
           struct vnode *vp;
           struct vfs_context context;
           int error = 0;
   
           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 && DTYPE_VNODE == FILEGLOB_DTYPE(fg) &&
               (p->p_ladvflag & P_LADVLOCK)) {
                   struct flock lf = {
                           .l_whence = SEEK_SET,
                           .l_type = F_UNLCK,
                   };
   
                   vp = (struct vnode *)fg_get_data(fg);
                   if ((error = vnode_getwithref(vp)) == 0) {
                           (void)VNOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_POSIX, &context, NULL);
                           (void)vnode_put(vp);
                   }
           }
   
           if (os_ref_release_raw(&fg->fg_count, &f_refgrp) == 0) {
                   /*
                    * Since we ensure that fg->fg_ops is always initialized,
                    * it is safe to invoke fo_close on the fg
                    */
                   error = fo_close(fg, &context);
   
                   fg_free(fg);
           }
   
           return error;
   }
   
   inline
   void
   fg_set_data(
           struct fileglob *fg,
           void *fg_data)
   {
           uintptr_t *store = &fg->fg_data;
   
   #if __has_feature(ptrauth_calls)
           int type = FILEGLOB_DTYPE(fg);
   
           if (fg_data) {
                   type ^= OS_PTRAUTH_DISCRIMINATOR("fileglob.fg_data");
                   fg_data = ptrauth_sign_unauthenticated(fg_data,
                       ptrauth_key_process_independent_data,
                       ptrauth_blend_discriminator(store, type));
           }
   #endif // __has_feature(ptrauth_calls)
   
           *store = (uintptr_t)fg_data;
   }
   
   inline
   void *
   fg_get_data_volatile(struct fileglob *fg)
   {
           uintptr_t *store = &fg->fg_data;
           void *fg_data = (void *)*store;
   
   #if __has_feature(ptrauth_calls)
           int type = FILEGLOB_DTYPE(fg);
   
           if (fg_data) {
                   type ^= OS_PTRAUTH_DISCRIMINATOR("fileglob.fg_data");
                   fg_data = ptrauth_auth_data(fg_data,
                       ptrauth_key_process_independent_data,
                       ptrauth_blend_discriminator(store, type));
           }
   #endif // __has_feature(ptrauth_calls)
   
           return fg_data;
   }
   
   static void
   fg_transfer_filelocks(proc_t p, struct fileglob *fg, thread_t thread)
   {
           struct vnode *vp;
           struct vfs_context context;
           struct proc *old_proc = current_proc();
   
           assert(fg != NULL);
   
           assert(p != old_proc);
           context.vc_thread = thread;
           context.vc_ucred = fg->fg_cred;
   
           /* Transfer all POSIX Style locks to new proc */
           if (p && DTYPE_VNODE == FILEGLOB_DTYPE(fg) &&
               (p->p_ladvflag & P_LADVLOCK)) {
                   struct flock lf = {
                           .l_whence = SEEK_SET,
                           .l_start = 0,
                           .l_len = 0,
                           .l_type = F_TRANSFER,
                   };
   
                   vp = (struct vnode *)fg_get_data(fg);
                   if (vnode_getwithref(vp) == 0) {
                           (void)VNOP_ADVLOCK(vp, (caddr_t)old_proc, F_TRANSFER, &lf, F_POSIX, &context, NULL);
                           (void)vnode_put(vp);
                   }
           }
   
           /* Transfer all OFD Style locks to new proc */
           if (p && DTYPE_VNODE == FILEGLOB_DTYPE(fg) &&
               (fg->fg_lflags & FG_HAS_OFDLOCK)) {
                   struct flock lf = {
                           .l_whence = SEEK_SET,
                           .l_start = 0,
                           .l_len = 0,
                           .l_type = F_TRANSFER,
                   };
   
                   vp = (struct vnode *)fg_get_data(fg);
                   if (vnode_getwithref(vp) == 0) {
                           (void)VNOP_ADVLOCK(vp, (caddr_t)fg, F_TRANSFER, &lf, F_OFD_LOCK, &context, NULL);
                           (void)vnode_put(vp);
                   }
           }
           return;
   }
   
   bool
   fg_sendable(struct fileglob *fg)
   {
           switch (FILEGLOB_DTYPE(fg)) {
           case DTYPE_VNODE:
           case DTYPE_SOCKET:
           case DTYPE_PIPE:
           case DTYPE_PSXSHM:
           case DTYPE_NETPOLICY:
                   return (fg->fg_lflags & FG_CONFINED) == 0;
   
           default:
                   return false;
           }
   }
   
   #pragma mark file descriptor table (static helpers)
   
   static 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_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);
           }
   }
   
   static void
   procfdtbl_waitfd(struct proc * p, int fd)
   {
           p->p_fd.fd_ofileflags[fd] |= UF_RESVWAIT;
           msleep(&p->p_fd, &p->p_fd.fd_lock, PRIBIO, "ftbl_waitfd", NULL);
   }
   
   static 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
    */
   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_afterlast) {
                   panic("fdrelse: fd_afterlast inconsistent");
           }
   #endif
           procfdtbl_clearfd(p, fd);
   
           nfd = fdp->fd_afterlast;
           while (nfd > 0 && fdp->fd_ofiles[nfd - 1] == NULL &&
               !(fdp->fd_ofileflags[nfd - 1] & UF_RESERVED)) {
                   nfd--;
           }
           fdp->fd_afterlast = nfd;
   
   #if CONFIG_PROC_RESOURCE_LIMITS
           fdp->fd_nfiles_open--;
   #endif /* CONFIG_PROC_RESOURCE_LIMITS */
   }
   
   
   /*
    * 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
    *              fp_flags                        Flags to augment the new fp
    *              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 changed out from under it.
    */
   static int
   finishdup(proc_t p, struct filedesc *fdp, int old, int new,
       fileproc_flags_t fp_flags, int32_t *retval)
   {
           struct fileproc *nfp;
           struct fileproc *ofp;
   #if CONFIG_MACF
           int error;
           kauth_cred_t cred;
   #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;
           }
   
   #if CONFIG_MACF
           cred = kauth_cred_proc_ref(p);
           error = mac_file_check_dup(cred, ofp->fp_glob, new);
           kauth_cred_unref(&cred);
   
           if (error) {
                   fdrelse(p, new);
                   return error;
           }
   #endif
   
           fg_ref(p, ofp->fp_glob);
   
           proc_fdunlock(p);
   
           nfp = fileproc_alloc_init();
   
           if (fp_flags) {
                   nfp->fp_flags |= fp_flags;
           }
           nfp->fp_glob = ofp->fp_glob;
   
           proc_fdlock(p);
   
   #if DIAGNOSTIC
           if (fdp->fd_ofiles[new] != 0) {
                   panic("finishdup: overwriting fd_ofiles with new %d", new);
           }
           if ((fdp->fd_ofileflags[new] & UF_RESERVED) == 0) {
                   panic("finishdup: unreserved fileflags with new %d", new);
           }
   #endif
   
           if (new >= fdp->fd_afterlast) {
                   fdp->fd_afterlast = new + 1;
           }
           procfdtbl_releasefd(p, new, nfp);
           *retval = new;
           return 0;
   }
   
   
   #pragma mark file descriptor table (exported functions)
   
   void
   proc_dirs_lock_shared(proc_t p)
   {
           lck_rw_lock_shared(&p->p_fd.fd_dirs_lock);
   }
   
   void
   proc_dirs_unlock_shared(proc_t p)
   {
           lck_rw_unlock_shared(&p->p_fd.fd_dirs_lock);
   }
   
   void
   proc_dirs_lock_exclusive(proc_t p)
   {
           lck_rw_lock_exclusive(&p->p_fd.fd_dirs_lock);
   }
   
   void
   proc_dirs_unlock_exclusive(proc_t p)
   {
           lck_rw_unlock_exclusive(&p->p_fd.fd_dirs_lock);
   }
   
   /*
    * 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_fd.fd_lock);
   }
   
   void
   proc_fdlock_spin(proc_t p)
   {
           lck_mtx_lock_spin(&p->p_fd.fd_lock);
   }
   
   void
   proc_fdlock_assert(proc_t p, int assertflags)
   {
           lck_mtx_assert(&p->p_fd.fd_lock, 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_fd.fd_lock);
   }
   
   bool
   fdt_available_locked(proc_t p, int n)
   {
           struct filedesc *fdp = &p->p_fd;
           struct fileproc **fpp;
           char *flags;
           int i;
           int lim = proc_limitgetcur_nofile(p);
   
           if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) {
                   return true;
           }
           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 true;
                   }
           }
           return false;
   }
   
   
   struct fdt_iterator
   fdt_next(proc_t p, int fd, bool only_settled)
   {
           struct fdt_iterator it;
           struct filedesc *fdp = &p->p_fd;
           struct fileproc *fp;
           int nfds = fdp->fd_afterlast;
   
           while (++fd < nfds) {
                   fp = fdp->fd_ofiles[fd];
                   if (fp == NULL || fp->fp_glob == NULL) {
                           continue;
                   }
                   if (only_settled && (fdp->fd_ofileflags[fd] & UF_RESERVED)) {
                           continue;
                   }
                   it.fdti_fd = fd;
                   it.fdti_fp = fp;
                   return it;
           }
   
           it.fdti_fd = nfds;
           it.fdti_fp = NULL;
           return it;
   }
   
   struct fdt_iterator
   fdt_prev(proc_t p, int fd, bool only_settled)
   {
           struct fdt_iterator it;
           struct filedesc *fdp = &p->p_fd;
           struct fileproc *fp;
   
           while (--fd >= 0) {
                   fp = fdp->fd_ofiles[fd];
                   if (fp == NULL || fp->fp_glob == NULL) {
                           continue;
                   }
                   if (only_settled && (fdp->fd_ofileflags[fd] & UF_RESERVED)) {
                           continue;
                   }
                   it.fdti_fd = fd;
                   it.fdti_fp = fp;
                   return it;
           }
   
           it.fdti_fd = -1;
           it.fdti_fp = NULL;
           return it;
   }
   
   void
   fdt_init(proc_t p)
   {
           struct filedesc *fdp = &p->p_fd;
   
           lck_mtx_init(&fdp->fd_kqhashlock, &proc_kqhashlock_grp, &proc_lck_attr);
           lck_mtx_init(&fdp->fd_knhashlock, &proc_knhashlock_grp, &proc_lck_attr);
           lck_mtx_init(&fdp->fd_lock, &proc_fdmlock_grp, &proc_lck_attr);
           lck_rw_init(&fdp->fd_dirs_lock, &proc_dirslock_grp, &proc_lck_attr);
   }
   
   void
   fdt_destroy(proc_t p)
   {
           struct filedesc *fdp = &p->p_fd;
   
           lck_mtx_destroy(&fdp->fd_kqhashlock, &proc_kqhashlock_grp);
           lck_mtx_destroy(&fdp->fd_knhashlock, &proc_knhashlock_grp);
           lck_mtx_destroy(&fdp->fd_lock, &proc_fdmlock_grp);
           lck_rw_destroy(&fdp->fd_dirs_lock, &proc_dirslock_grp);
   }
   
   void
   fdt_exec(proc_t p, short posix_spawn_flags, thread_t thread, bool in_exec)
   {
           struct filedesc *fdp = &p->p_fd;
           thread_t self = current_thread();
           struct uthread *ut = get_bsdthread_info(self);
           struct kqworkq *dealloc_kqwq = NULL;
   
           /*
            * If the current thread is bound as a workq/workloop
            * servicing thread, we need to unbind it first.
            */
           if (ut->uu_kqr_bound && get_bsdthreadtask_info(self) == p) {
                   kqueue_threadreq_unbind(p, ut->uu_kqr_bound);
           }
   
           /*
            * Deallocate the knotes for this process
            * and mark the tables non-existent so
            * subsequent kqueue closes go faster.
            */
           knotes_dealloc(p);
           assert(fdp->fd_knlistsize == 0);
           assert(fdp->fd_knhashmask == 0);
   
           proc_fdlock(p);
   
           /* Set the P_LADVLOCK flag if the flag set on old proc */
           if (in_exec && (current_proc()->p_ladvflag & P_LADVLOCK)) {
                   os_atomic_or(&p->p_ladvflag, P_LADVLOCK, relaxed);
           }
   
           for (int i = fdp->fd_afterlast; i-- > 0;) {
                   struct fileproc *fp = fdp->fd_ofiles[i];
                   char *flagp = &fdp->fd_ofileflags[i];
                   bool inherit_file = true;
   
                   if (fp == FILEPROC_NULL) {
                           continue;
                   }
   
                   /*
                    * no file descriptor should be in flux when in exec,
                    * because we stopped all other threads
                    */
                   if (*flagp & ~UF_INHERIT) {
                           panic("file %d/%p in flux during exec of %p", i, fp, p);
                   }
   
                   if (fp->fp_flags & FP_CLOEXEC) {
                           inherit_file = false;
                   } else if ((posix_spawn_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) &&
                       !(*flagp & UF_INHERIT)) {
                           /*
                            * Reverse the usual semantics of file descriptor
                            * inheritance - all of them should be closed
                            * except files marked explicitly as "inherit" and
                            * not marked close-on-exec.
                            */
                           inherit_file = false;
   #if CONFIG_MACF
                   } else if (mac_file_check_inherit(proc_ucred(p), fp->fp_glob)) {
                           inherit_file = false;
   #endif
                   }
   
                   *flagp = 0; /* clear UF_INHERIT */
   
                   if (!inherit_file) {
                           fp_close_and_unlock(p, i, fp, 0);
                           proc_fdlock(p);
                   } else if (in_exec) {
                           /* Transfer F_POSIX style lock to new proc */
                           proc_fdunlock(p);
                           fg_transfer_filelocks(p, fp->fp_glob, thread);
                           proc_fdlock(p);
                   }
           }
   
           /* release the per-process workq kq */
           if (fdp->fd_wqkqueue) {
                   dealloc_kqwq = fdp->fd_wqkqueue;
                   fdp->fd_wqkqueue = NULL;
           }
   
           proc_fdunlock(p);
   
           /* Anything to free? */
           if (dealloc_kqwq) {
                   kqworkq_dealloc(dealloc_kqwq);
           }
   }
   
   
   int
   fdt_fork(struct filedesc *newfdp, proc_t p, vnode_t uth_cdir, bool in_exec)
   {
           struct filedesc *fdp = &p->p_fd;
           struct fileproc **ofiles;
           char *ofileflags;
           int n_files, afterlast, freefile;
           vnode_t v_dir;
   #if CONFIG_PROC_RESOURCE_LIMITS
           int fd_nfiles_open = 0;
   #endif /* CONFIG_PROC_RESOURCE_LIMITS */
           proc_fdlock(p);
   
           newfdp->fd_flags = (fdp->fd_flags & FILEDESC_FORK_INHERITED_MASK);
           newfdp->fd_cmask = fdp->fd_cmask;
   #if CONFIG_PROC_RESOURCE_LIMITS
           newfdp->fd_nfiles_soft_limit = fdp->fd_nfiles_soft_limit;
           newfdp->fd_nfiles_hard_limit = fdp->fd_nfiles_hard_limit;
   #endif /* CONFIG_PROC_RESOURCE_LIMITS */
   
           /*
            * 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 = fdp->fd_rdir)) {
                   if (vnode_getwithref(v_dir) == 0) {
                           if (vnode_ref(v_dir) == 0) {
                                   newfdp->fd_rdir = v_dir;
                           }
                           vnode_put(v_dir);
                   }
                   if (newfdp->fd_rdir == NULL) {
                           /*
                            * 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.
                            */
                           proc_fdunlock(p);
                           return EPERM;
                   }
           }
   
           /*
            * If we are running with per-thread current working directories,
            * inherit the new current working directory from the current thread.
            */
           if ((v_dir = uth_cdir ? uth_cdir : fdp->fd_cdir)) {
                   if (vnode_getwithref(v_dir) == 0) {
                           if (vnode_ref(v_dir) == 0) {
                                   newfdp->fd_cdir = v_dir;
                           }
                           vnode_put(v_dir);
                   }
                   if (newfdp->fd_cdir == NULL && v_dir == 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 recycling it
                            */
                           vnode_rele(fdp->fd_cdir);
                           fdp->fd_cdir = NULL;
                   }
           }
   
           /*
            * 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.
            */
           afterlast = fdp->fd_afterlast;
           freefile = fdp->fd_freefile;
           if (afterlast <= NDFILE) {
                   n_files = NDFILE;
           } else {
                   n_files = roundup(afterlast, NDEXTENT);
           }
   
           proc_fdunlock(p);
   
           ofiles = fd_alloc_files(n_files, Z_WAITOK | Z_ZERO);
           if (ofiles == NULL) {
                   if (newfdp->fd_cdir) {
                           vnode_rele(newfdp->fd_cdir);
                           newfdp->fd_cdir = NULL;
                   }
                   if (newfdp->fd_rdir) {
                           vnode_rele(newfdp->fd_rdir);
                           newfdp->fd_rdir = NULL;
                   }
                   return ENOMEM;
           }
           ofileflags = (char *)&ofiles[n_files];
   
           proc_fdlock(p);
   
           for (int i = afterlast; i-- > 0;) {
                   struct fileproc *ofp, *nfp;
                   char flags;
   
                   ofp = fdp->fd_ofiles[i];
                   flags = fdp->fd_ofileflags[i];
   
                   if (ofp == NULL ||
                       (ofp->fp_glob->fg_lflags & FG_CONFINED) ||
                       ((ofp->fp_flags & FP_CLOFORK) && !in_exec) ||
                       ((ofp->fp_flags & FP_CLOEXEC) && in_exec) ||
                       (flags & UF_RESERVED)) {
                           if (i + 1 == afterlast) {
                                   afterlast = i;
                           }
                           if (i < freefile) {
                                   freefile = i;
                           }
   
                           continue;
                   }
   
                   nfp = fileproc_alloc_init();
                   nfp->fp_glob = ofp->fp_glob;
                   if (in_exec) {
                           nfp->fp_flags = (ofp->fp_flags & (FP_CLOEXEC | FP_CLOFORK));
                           if (ofp->fp_guard_attrs) {
                                   guarded_fileproc_copy_guard(ofp, nfp);
                           }
                   } else {
                           assert(ofp->fp_guard_attrs == 0);
                           nfp->fp_flags = (ofp->fp_flags & FP_CLOEXEC);
                   }
                   fg_ref(p, nfp->fp_glob);
   
                   ofiles[i] = nfp;
   #if CONFIG_PROC_RESOURCE_LIMITS
                   fd_nfiles_open++;
   #endif /* CONFIG_PROC_RESOURCE_LIMITS */
           }
   
           proc_fdunlock(p);
   
           newfdp->fd_ofiles = ofiles;
           newfdp->fd_ofileflags = ofileflags;
           newfdp->fd_nfiles = n_files;
           newfdp->fd_afterlast = afterlast;
           newfdp->fd_freefile = freefile;
   
   #if CONFIG_PROC_RESOURCE_LIMITS
           newfdp->fd_nfiles_open = fd_nfiles_open;
   #endif /* CONFIG_PROC_RESOURCE_LIMITS */
   
           return 0;
   }
   
   void
   fdt_invalidate(proc_t p)
  {
          struct filedesc *fdp = &p->p_fd;
          struct fileproc *fp, **ofiles;
          struct kqworkq *kqwq = NULL;
          vnode_t vn1 = NULL, vn2 = NULL;
          struct kqwllist *kqhash = NULL;
          u_long kqhashmask = 0;
          int n_files = 0;
  
          /*
           * deallocate all the knotes up front and claim empty
           * tables to make any subsequent kqueue closes faster.
           */
          knotes_dealloc(p);
          assert(fdp->fd_knlistsize == 0);
          assert(fdp->fd_knhashmask == 0);
  
          /*
           * dealloc all workloops that have outstanding retains
           * when created with scheduling parameters.
           */
          kqworkloops_dealloc(p);
  
          proc_fdlock(p);
  
          /* close file descriptors */
          if (fdp->fd_nfiles > 0 && fdp->fd_ofiles) {
                  for (int i = fdp->fd_afterlast; i-- > 0;) {
                          if ((fp = fdp->fd_ofiles[i]) != NULL) {
                                  if (fdp->fd_ofileflags[i] & UF_RESERVED) {
                                          panic("fdfree: found fp with UF_RESERVED");
                                  }
                                  fp_close_and_unlock(p, i, fp, 0);
                                  proc_fdlock(p);
                          }
                  }
          }
  
          n_files = fdp->fd_nfiles;
          ofiles = fdp->fd_ofiles;
          kqwq = fdp->fd_wqkqueue;
          vn1 = fdp->fd_cdir;
          vn2 = fdp->fd_rdir;
  
          fdp->fd_ofileflags = NULL;
          fdp->fd_ofiles = NULL;
          fdp->fd_nfiles = 0;
          fdp->fd_wqkqueue = NULL;
          fdp->fd_cdir = NULL;
          fdp->fd_rdir = NULL;
  
          proc_fdunlock(p);
  
          lck_mtx_lock(&fdp->fd_knhashlock);
  
          kqhash = fdp->fd_kqhash;
          kqhashmask = fdp->fd_kqhashmask;
  
          fdp->fd_kqhash = 0;
          fdp->fd_kqhashmask = 0;
  
          lck_mtx_unlock(&fdp->fd_knhashlock);
  
          fd_free_files(ofiles, n_files);
  
          if (kqwq) {
                  kqworkq_dealloc(kqwq);
          }
          if (vn1) {
                  vnode_rele(vn1);
          }
          if (vn2) {
                  vnode_rele(vn2);
          }
          if (kqhash) {
                  for (uint32_t i = 0; i <= kqhashmask; i++) {
                          assert(LIST_EMPTY(&kqhash[i]));
                  }
                  hashdestroy(kqhash, M_KQUEUE, kqhashmask);
          }
  }
  
  
  struct fileproc *
  fileproc_alloc_init(void)
  {
          struct fileproc *fp;
  
          fp = zalloc_id(ZONE_ID_FILEPROC, Z_WAITOK | Z_ZERO | Z_NOFAIL);
          os_ref_init(&fp->fp_iocount, &f_refgrp);
          return fp;
  }
  
  
  void
  fileproc_free(struct fileproc *fp)
  {
          os_ref_count_t __unused refc = os_ref_release(&fp->fp_iocount);
  #if DEVELOPMENT || DEBUG
          if (0 != refc) {
                  panic("%s: pid %d refc: %u != 0",
                      __func__, proc_pid(current_proc()), refc);
          }
  #endif
          if (fp->fp_guard_attrs) {
                  guarded_fileproc_unguard(fp);
          }
          assert(fp->fp_wset == NULL);
          zfree_id(ZONE_ID_FILEPROC, fp);
  }
  
  
  /*
   * 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;
  
  #if CONFIG_PROC_RESOURCE_LIMITS
  /*
   * Should be called only with the proc_fdlock held.
   */
  void
  fd_check_limit_exceeded(struct filedesc *fdp)
  {
  #if DIAGNOSTIC
          proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
  #endif
          if (!fd_above_soft_limit_notify(fdp) && fdp->fd_nfiles_soft_limit &&
              (fdp->fd_nfiles_open > fdp->fd_nfiles_soft_limit)) {
                  fd_above_soft_limit_send_notification(fdp);
                  act_set_astproc_resource(current_thread());
          } else if (!fd_above_hard_limit_notify(fdp) && fdp->fd_nfiles_hard_limit &&
              (fdp->fd_nfiles_open > fdp->fd_nfiles_hard_limit)) {
                  fd_above_hard_limit_send_notification(fdp);
                  act_set_astproc_resource(current_thread());
          }
  }
  #endif /* CONFIG_PROC_RESOURCE_LIMITS */
  
  /*
   * 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 last, numfiles, oldnfiles;
          struct fileproc **newofiles, **ofiles;
          char *newofileflags;
          int lim = proc_limitgetcur_nofile(p);
  
          /*
           * 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
  
          for (;;) {
                  last = (int)MIN((unsigned int)fdp->fd_nfiles, (unsigned int)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_afterlast) {
                                          fdp->fd_afterlast = i + 1;
                                  }
                                  if (want <= fdp->fd_freefile) {
                                          fdp->fd_freefile = i;
                                  }
                                  *result = i;
  #if CONFIG_PROC_RESOURCE_LIMITS
                                  fdp->fd_nfiles_open++;
                                  fd_check_limit_exceeded(fdp);
  #endif /* CONFIG_PROC_RESOURCE_LIMITS */
                                  return 0;
                          }
                  }
  
                  /*
                   * No space in current array.  Expand?
                   */
                  if ((rlim_t)fdp->fd_nfiles >= lim) {
                          return EMFILE;
                  }
                  if (fdp->fd_nfiles < NDEXTENT) {
                          numfiles = NDEXTENT;
                  } else {
                          numfiles = 2 * fdp->fd_nfiles;
                  }
                  /* Enforce lim */
                  if ((rlim_t)numfiles > lim) {
                          numfiles = (int)lim;
                  }
                  proc_fdunlock(p);
                  newofiles = fd_alloc_files(numfiles, Z_WAITOK);
                  proc_fdlock(p);
                  if (newofiles == NULL) {
                          return ENOMEM;
                  }
                  if (fdp->fd_nfiles >= numfiles) {
                          fd_free_files(newofiles, numfiles);
                          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;
                  fd_free_files(ofiles, oldnfiles);
                  fdexpand++;
          }
  }
  
  
  #pragma mark fileprocs
  
  void
  fileproc_modify_vflags(struct fileproc *fp, fileproc_vflags_t vflags, boolean_t clearflags)
  {
          if (clearflags) {
                  os_atomic_andnot(&fp->fp_vflags, vflags, relaxed);
          } else {
                  os_atomic_or(&fp->fp_vflags, vflags, relaxed);
          }
  }
  
  fileproc_vflags_t
  fileproc_get_vflags(struct fileproc *fp)
  {
          return os_atomic_load(&fp->fp_vflags, relaxed);
  }
  
  /*
   * falloc_withinit
   *
   * Create a new open file structure and allocate
   * a file descriptor 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
   *              fp_zalloc                       fileproc allocator to use
   *              crarg                           allocator args
   *
   * Returns:     0                               Success
   *              ENFILE                          Too many open files in system
   *              fdalloc:EMFILE                  Too many open files in process
   *              fdalloc:ENOMEM                  M_OFILETABL zone exhausted
   *              ENOMEM                          fp_zone or fg_zone zone
   *                                              exhausted
   *
   * Implicit returns:
   *              *resultfd (modified)            Returned fileproc pointer
   *              *resultfd (modified)            Returned fd
   *
   * Notes:       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_withinit(proc_t p, struct fileproc **resultfp, int *resultfd,
      vfs_context_t ctx, fp_initfn_t fp_init, void *initarg)
  {
          struct fileproc *fp;
          struct fileglob *fg;
          int error, nfd;
  #if CONFIG_MACF
          kauth_cred_t cred;
  #endif
  
          /* Make sure we don't go beyond the system-wide limit */
          if (nfiles >= maxfiles) {
                  tablefull("file");
                  return ENFILE;
          }
  
          proc_fdlock(p);
  
          /* fdalloc will make sure the process stays below per-process limit */
          if ((error = fdalloc(p, 0, &nfd))) {
                  proc_fdunlock(p);
                  return error;
          }
  
  #if CONFIG_MACF
          cred = kauth_cred_proc_ref(p);
          error = mac_file_check_create(cred);
          kauth_cred_unref(&cred);
          if (error) {
                  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);
  
          fp = fileproc_alloc_init();
          if (fp_init) {
                  fp_init(fp, initarg);
          }
  
          fg = zalloc_flags(fg_zone, Z_WAITOK | Z_ZERO);
          lck_mtx_init(&fg->fg_lock, &file_lck_grp, LCK_ATTR_NULL);
  
          os_ref_retain_locked(&fp->fp_iocount);
          os_ref_init_raw(&fg->fg_count, &f_refgrp);
          fg->fg_ops = &uninitops;
          fp->fp_glob = fg;
  
          kauth_cred_ref(ctx->vc_ucred);
  
          fp->f_cred = ctx->vc_ucred;
  
          os_atomic_inc(&nfiles, relaxed);
  
          proc_fdlock(p);
  
          p->p_fd.fd_ofiles[nfd] = fp;
  
          proc_fdunlock(p);
  
          if (resultfp) {
                  *resultfp = fp;
          }
          if (resultfd) {
                  *resultfd = nfd;
          }
  
          return 0;
  }
  
  int
  falloc(proc_t p, struct fileproc **resultfp, int *resultfd, vfs_context_t ctx)
  {
          return falloc_withinit(p, resultfp, resultfd, ctx, NULL, 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
   */
  void
  fp_free(proc_t p, int fd, struct fileproc * fp)
  {
          proc_fdlock_spin(p);
          fdrelse(p, fd);
          proc_fdunlock(p);
  
          fg_free(fp->fp_glob);
          os_ref_release_live(&fp->fp_iocount);
          fileproc_free(fp);
  }
  
  
  struct fileproc *
  fp_get_noref_locked(proc_t p, int fd)
  {
          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 NULL;
          }
  
          zone_id_require(ZONE_ID_FILEPROC, sizeof(*fp), fp);
          return fp;
  }
  
  struct fileproc *
  fp_get_noref_locked_with_iocount(proc_t p, int fd)
  {
          struct filedesc *fdp = &p->p_fd;
          struct fileproc *fp = NULL;
  
          if (fd < 0 || fd >= fdp->fd_nfiles ||
              (fp = fdp->fd_ofiles[fd]) == NULL ||
              os_ref_get_count(&fp->fp_iocount) <= 1 ||
              ((fdp->fd_ofileflags[fd] & UF_RESERVED) &&
              !(fdp->fd_ofileflags[fd] & UF_CLOSING))) {
                  panic("%s: caller without an ioccount on fileproc (%d/:%p)",
                      __func__, fd, fp);
          }
  
          zone_id_require(ZONE_ID_FILEPROC, sizeof(*fp), fp);
          return fp;
  }
  
  
  /*
   * 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 fp_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;
          }
  
          zone_id_require(ZONE_ID_FILEPROC, sizeof(*fp), fp);
          os_ref_retain_locked(&fp->fp_iocount);
  
          if (resultfp) {
                  *resultfp = fp;
          }
          if (!locked) {
                  proc_fdunlock(p);
          }
  
          return 0;
  }
  
  
  int
  fp_get_ftype(proc_t p, int fd, file_type_t ftype, int err, struct fileproc **fpp)
  {
          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 != ftype) {
                  proc_fdunlock(p);
                  return err;
          }
  
          zone_id_require(ZONE_ID_FILEPROC, sizeof(*fp), fp);
          os_ref_retain_locked(&fp->fp_iocount);
          proc_fdunlock(p);
  
          *fpp = fp;
          return 0;
  }
  
  
  /*
   * 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;
          }
  
          if (1 == os_ref_release_locked(&fp->fp_iocount)) {
                  if (fp->fp_flags & FP_SELCONFLICT) {
                          fp->fp_flags &= ~FP_SELCONFLICT;
                  }
  
                  if (fdp->fd_fpdrainwait) {
                          fdp->fd_fpdrainwait = 0;
                          needwakeup = 1;
                  }
          }
          if (!locked) {
                  proc_fdunlock(p);
          }
          if (needwakeup) {
                  wakeup(&fdp->fd_fpdrainwait);
          }
  
          return 0;
  }
  
  
  /*
   * 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 descriptors, 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.
   */
  static void
  fileproc_drain(proc_t p, struct fileproc * fp)
  {
          struct filedesc *fdp = &p->p_fd;
          struct vfs_context context;
          thread_t thread;
          bool is_current_proc;
  
          is_current_proc = (p == current_proc());
  
          if (!is_current_proc) {
                  proc_lock(p);
                  thread = proc_thread(p); /* XXX */
                  thread_reference(thread);
                  proc_unlock(p);
          } else {
                  thread = current_thread();
          }
  
          context.vc_thread = thread;
          context.vc_ucred = fp->fp_glob->fg_cred;
  
          /* Set the vflag for drain */
          fileproc_modify_vflags(fp, FPV_DRAIN, FALSE);
  
          while (os_ref_get_count(&fp->fp_iocount) > 1) {
                  lck_mtx_convert_spin(&fdp->fd_lock);
  
                  fo_drain(fp, &context);
                  if ((fp->fp_flags & FP_INSELECT) == FP_INSELECT) {
                          struct select_set *selset;
  
                          if (fp->fp_guard_attrs) {
                                  selset = fp->fp_guard->fpg_wset;
                          } else {
                                  selset = fp->fp_wset;
                          }
                          if (waitq_wakeup64_all(selset, NO_EVENT64,
                              THREAD_INTERRUPTED, WAITQ_WAKEUP_DEFAULT) == KERN_INVALID_ARGUMENT) {
                                  panic("bad wait queue for waitq_wakeup64_all %p (%sfp:%p)",
                                      selset, fp->fp_guard_attrs ? "guarded " : "", fp);
                          }
                  }
                  if ((fp->fp_flags & FP_SELCONFLICT) == FP_SELCONFLICT) {
                          if (waitq_wakeup64_all(&select_conflict_queue, NO_EVENT64,
                              THREAD_INTERRUPTED, WAITQ_WAKEUP_DEFAULT) == KERN_INVALID_ARGUMENT) {
                                  panic("bad select_conflict_queue");
                          }
                  }
                  fdp->fd_fpdrainwait = 1;
                  msleep(&fdp->fd_fpdrainwait, &fdp->fd_lock, PRIBIO, "fpdrain", NULL);
          }
  #if DIAGNOSTIC
          if ((fp->fp_flags & FP_INSELECT) != 0) {
                  panic("FP_INSELECT set on drained fp");
          }
  #endif
          if ((fp->fp_flags & FP_SELCONFLICT) == FP_SELCONFLICT) {
                  fp->fp_flags &= ~FP_SELCONFLICT;
          }
  
          if (!is_current_proc) {
                  thread_deallocate(thread);
          }
  }
  
  
  int
  fp_close_and_unlock(proc_t p, int fd, struct fileproc *fp, int flags)
  {
          struct filedesc *fdp = &p->p_fd;
          struct fileglob *fg = fp->fp_glob;
  #if CONFIG_MACF
          kauth_cred_t cred;
  #endif
  
  #if DIAGNOSTIC
          proc_fdlock_assert(p, LCK_MTX_ASSERT_OWNED);
  #endif
  
          /*
           * Keep most people from finding the filedesc while we are closing it.
           *
           * Callers are:
           *
           * - dup2() which always waits for UF_RESERVED to clear
           *
           * - close/guarded_close/... who will fail the fileproc lookup if
           *   UF_RESERVED is set,
           *
           * - fdexec()/fdfree() who only run once all threads in the proc
           *   are properly canceled, hence no fileproc in this proc should
           *   be in flux.
           *
           * Which means that neither UF_RESERVED nor UF_CLOSING should be set.
           *
           * Callers of fp_get_noref_locked_with_iocount() can still find
           * this entry so that they can drop their I/O reference despite
           * not having remembered the fileproc pointer (namely select() and
           * file_drop()).
           */
          if (p->p_fd.fd_ofileflags[fd] & (UF_RESERVED | UF_CLOSING)) {
                  panic("%s: called with fileproc in flux (%d/:%p)",
                      __func__, fd, fp);
          }
          p->p_fd.fd_ofileflags[fd] |= (UF_RESERVED | UF_CLOSING);
  
          if ((fp->fp_flags & FP_AIOISSUED) ||
  #if CONFIG_MACF
              (FILEGLOB_DTYPE(fg) == DTYPE_VNODE)
  #else
              kauth_authorize_fileop_has_listeners()
  #endif
              ) {
                  proc_fdunlock(p);
  
                  if (FILEGLOB_DTYPE(fg) == DTYPE_VNODE) {
                          /*
                           * call out to allow 3rd party notification of close.
                           * Ignore result of kauth_authorize_fileop call.
                           */
  #if CONFIG_MACF
                          cred = kauth_cred_proc_ref(p);
                          mac_file_notify_close(cred, fp->fp_glob);
                          kauth_cred_unref(&cred);
  #endif
  
                          if (kauth_authorize_fileop_has_listeners() &&
                              vnode_getwithref((vnode_t)fg_get_data(fg)) == 0) {
                                  u_int   fileop_flags = 0;
                                  if (fg->fg_flag & FWASWRITTEN) {
                                          fileop_flags |= KAUTH_FILEOP_CLOSE_MODIFIED;
                                  }
                                  kauth_authorize_fileop(fg->fg_cred, KAUTH_FILEOP_CLOSE,
                                      (uintptr_t)fg_get_data(fg), (uintptr_t)fileop_flags);
  
                                  vnode_put((vnode_t)fg_get_data(fg));
                          }
                  }
  
                  if (fp->fp_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);
          }
  
          fileproc_drain(p, fp);
  
          if (flags & FD_DUP2RESV) {
                  fdp->fd_ofiles[fd] = NULL;
                  fdp->fd_ofileflags[fd] &= ~UF_CLOSING;
          } else {
                  fdrelse(p, fd);
          }
  
          proc_fdunlock(p);
  
          if (ENTR_SHOULDTRACE && FILEGLOB_DTYPE(fg) == DTYPE_SOCKET) {
                  KERNEL_ENERGYTRACE(kEnTrActKernSocket, DBG_FUNC_END,
                      fd, 0, (int64_t)VM_KERNEL_ADDRPERM(fg_get_data(fg)));
          }
  
          fileproc_free(fp);
  
          return fg_drop(p, fg);
  }
  
  /*
   * dupfdopen
   *
   * Description: Duplicate the specified descriptor to a free descriptor;
   *              this is the second half of fdopen(), above.
   *
   * Parameters:  p                               current process pointer
   *              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(proc_t p, int indx, int dfd, int flags, int error)
  {
          struct filedesc *fdp = &p->p_fd;
          struct fileproc *wfp;
          struct fileproc *fp;
  #if CONFIG_MACF
          int myerror;
  #endif
  
          /*
           * 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(kauth_cred_get(), wfp->fp_glob, 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:
                  if (fp_isguarded(wfp, GUARD_DUP)) {
                          proc_fdunlock(p);
                          return EPERM;
                  }
  
                  /*
                   * Check that the mode the file is being opened for is a
                   * subset of the mode of the existing descriptor.
                   */
                  if (((flags & (FREAD | FWRITE)) | wfp->f_flag) != wfp->f_flag) {
                          proc_fdunlock(p);
                          return EACCES;
                  }
                  if (indx >= fdp->fd_afterlast) {
                          fdp->fd_afterlast = indx + 1;
                  }
  
                  if (fp->fp_glob) {
                          fg_free(fp->fp_glob);
                  }
                  fg_ref(p, wfp->fp_glob);
                  fp->fp_glob = wfp->fp_glob;
                  /*
                   * Historically, open(/dev/fd/<n>) preserves close on fork/exec,
                   * unlike dup(), dup2() or fcntl(F_DUPFD).
                   *
                   * open1() already handled O_CLO{EXEC,FORK}
                   */
                  fp->fp_flags |= (wfp->fp_flags & (FP_CLOFORK | FP_CLOEXEC));
  
                  procfdtbl_releasefd(p, indx, NULL);
                  fp_drop(p, indx, fp, 1);
                  proc_fdunlock(p);
                  return 0;
  
          default:
                  proc_fdunlock(p);
                  return error;
          }
          /* NOTREACHED */
  }
  
  
  #pragma mark KPIS (sys/file.h)
  
  /*
   * fg_get_vnode
   *
   * Description: Return vnode associated with the file structure, if
   *              any.  The lifetime of the returned vnode is bound to
   *              the lifetime of the file structure.
   *
   * Parameters:  fg                              Pointer to fileglob to
   *                                              inspect
   *
   * Returns:     vnode_t
   */
  vnode_t
  fg_get_vnode(struct fileglob *fg)
  {
          if (FILEGLOB_DTYPE(fg) == DTYPE_VNODE) {
                  return (vnode_t)fg_get_data(fg);
          } else {
                  return NULL;
          }
  }
  
  
  /*
   * 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 fp_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 fileproc *fp;
          int error;
  
          error = fp_get_ftype(p, fd, DTYPE_VNODE, ENOTSUP, &fp);
          if (error == 0) {
                  if (resultfp) {
                          *resultfp = fp;
                  }
                  if (resultvp) {
                          *resultvp = (struct vnode *)fp_get_data(fp);
                  }
          }
  
          return error;
  }
  
  
  /*
   * fp_get_pipe_id
   *
   * Description: Get pipe id for a given fd from the per process open file table
   *              of the specified process.
   *
   * Parameters:  p                               Process in which fd lives
   *              fd                              fd to get information for
   *              result_pipe_id                  Pointer to result pipe id
   *
   * Returns:     0                               Success
   *              EIVAL                           NULL pointer arguments passed
   *              fp_lookup:EBADF                 Bad file descriptor
   *              ENOTSUP                         fd does not refer to a pipe
   *
   * Implicit returns:
   *              *result_pipe_id (modified)      pipe id
   *
   * Locks:       Internally takes and releases proc_fdlock
   */
  int
  fp_get_pipe_id(proc_t p, int fd, uint64_t *result_pipe_id)
  {
          struct fileproc *fp = FILEPROC_NULL;
          struct fileglob *fg = NULL;
          int error = 0;
  
          if (p == NULL || result_pipe_id == NULL) {
                  return EINVAL;
          }
  
          proc_fdlock(p);
          if ((error = fp_lookup(p, fd, &fp, 1))) {
                  proc_fdunlock(p);
                  return error;
          }
          fg = fp->fp_glob;
  
          if (FILEGLOB_DTYPE(fg) == DTYPE_PIPE) {
                  *result_pipe_id = pipe_id((struct pipe*)fg_get_data(fg));
          } else {
                  error = ENOTSUP;
          }
  
          fp_drop(p, fd, fp, 1);
          proc_fdunlock(p);
          return error;
  }
  
  
  /*
   * 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 fp_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 inherently 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 fp_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)
  {
          return file_vnode_withvid(fd, vpp, NULL);
  }
  
  
  /*
   * file_vnode_withvid
   *
   * 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
   *              vidp                            pointer to vid of the returned vnode
   *
   * 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 fp_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 inherently 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 fp_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_withvid(int fd, struct vnode **vpp, uint32_t *vidp)
  {
          struct fileproc *fp;
          int error;
  
          error = fp_get_ftype(current_proc(), fd, DTYPE_VNODE, EINVAL, &fp);
          if (error == 0) {
                  if (vpp) {
                          *vpp = (struct vnode *)fp_get_data(fp);
                  }
                  if (vidp) {
                          *vidp = vnode_vid((struct vnode *)fp_get_data(fp));
                  }
          }
          return error;
  }
  
  /*
   * 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 fp_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 inherently 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 fp_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)
  {
          struct fileproc *fp;
          int error;
  
          error = fp_get_ftype(current_proc(), fd, DTYPE_SOCKET, ENOTSOCK, &fp);
          if (error == 0) {
                  if (sp) {
                          *sp = (struct socket *)fp_get_data(fp);
                  }
          }
          return error;
  }
  
  
  /*
   * 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
   */
  int
  file_flags(int fd, int *flags)
  {
          proc_t p = current_proc();
          struct fileproc *fp;
          int error = EBADF;
  
          proc_fdlock_spin(p);
          fp = fp_get_noref_locked(p, fd);
          if (fp) {
                  *flags = (int)fp->f_flag;
                  error = 0;
          }
          proc_fdunlock(p);
  
          return error;
  }
  
  
  /*
   * 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
   *
   * Description: Given an fd, look it up in the current process's per process
   *              open file table, and drop it's fileproc's fp_iocount by one
   *
   * Notes:       This is intended as a corresponding operation to the functions
   *              file_vnode() and file_socket() operations.
   *
   *              If the caller can't possibly hold an I/O reference,
   *              this function will panic the kernel rather than allowing
   *              for memory corruption. Callers should always call this
   *              because they acquired an I/O reference on this file before.
   *
   *              Use of this function is discouraged.
   */
  int
  file_drop(int fd)
  {
          struct fileproc *fp;
          proc_t p = current_proc();
          struct filedesc *fdp = &p->p_fd;
          int     needwakeup = 0;
  
          proc_fdlock_spin(p);
          fp = fp_get_noref_locked_with_iocount(p, fd);
  
          if (1 == os_ref_release_locked(&fp->fp_iocount)) {
                  if (fp->fp_flags & FP_SELCONFLICT) {
                          fp->fp_flags &= ~FP_SELCONFLICT;
                  }
  
                  if (fdp->fd_fpdrainwait) {
                          fdp->fd_fpdrainwait = 0;
                          needwakeup = 1;
                  }
          }
          proc_fdunlock(p);
  
          if (needwakeup) {
                  wakeup(&fdp->fd_fpdrainwait);
          }
          return 0;
  }
  
  
  #pragma mark syscalls
  
  #ifndef HFS_GET_BOOT_INFO
  #define HFS_GET_BOOT_INFO   (FCNTL_FS_SPECIFIC_BASE + 0x00004)
  #endif
  
  #ifndef HFS_SET_BOOT_INFO
  #define HFS_SET_BOOT_INFO   (FCNTL_FS_SPECIFIC_BASE + 0x00005)
  #endif
  
  #ifndef APFSIOC_REVERT_TO_SNAPSHOT
  #define APFSIOC_REVERT_TO_SNAPSHOT  _IOW('J', 1, u_int64_t)
  #endif
  
  #define CHECK_ADD_OVERFLOW_INT64L(x, y) \
                  (((((x) > 0) && ((y) > 0) && ((x) > LLONG_MAX - (y))) || \
                  (((x) < 0) && ((y) < 0) && ((x) < LLONG_MIN - (y)))) \
                  ? 1 : 0)
  
  /*
   * sys_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
  sys_getdtablesize(proc_t p, __unused struct getdtablesize_args *uap, int32_t *retval)
  {
          *retval = proc_limitgetcur_nofile(p);
          return 0;
  }
  
  
  /*
   * check_file_seek_range
   *
   * Description: Checks if seek offsets are in the range of 0 to LLONG_MAX.
   *
   * Parameters:  fl              Flock structure.
   *              cur_file_offset Current offset in the file.
   *
   * Returns:     0               on Success.
   *              EOVERFLOW       on overflow.
   *              EINVAL          on offset less than zero.
   */
  
  static int
  check_file_seek_range(struct flock *fl, off_t cur_file_offset)
  {
          if (fl->l_whence == SEEK_CUR) {
                  /* Check if the start marker is beyond LLONG_MAX. */
                  if (CHECK_ADD_OVERFLOW_INT64L(fl->l_start, cur_file_offset)) {
                          /* Check if start marker is negative */
                          if (fl->l_start < 0) {
                                  return EINVAL;
                          }
                          return EOVERFLOW;
                  }
                  /* Check if the start marker is negative. */
                  if (fl->l_start + cur_file_offset < 0) {
                          return EINVAL;
                  }
                  /* Check if end marker is beyond LLONG_MAX. */
                  if ((fl->l_len > 0) && (CHECK_ADD_OVERFLOW_INT64L(fl->l_start +
                      cur_file_offset, fl->l_len - 1))) {
                          return EOVERFLOW;
                  }
                  /* Check if the end marker is negative. */
                  if ((fl->l_len <= 0) && (fl->l_start + cur_file_offset +
                      fl->l_len < 0)) {
                          return EINVAL;
                  }
          } else if (fl->l_whence == SEEK_SET) {
                  /* Check if the start marker is negative. */
                  if (fl->l_start < 0) {
                          return EINVAL;
                  }
                  /* Check if the end marker is beyond LLONG_MAX. */
                  if ((fl->l_len > 0) &&
                      CHECK_ADD_OVERFLOW_INT64L(fl->l_start, fl->l_len - 1)) {
                          return EOVERFLOW;
                  }
                  /* Check if the end marker is negative. */
                  if ((fl->l_len < 0) && fl->l_start + fl->l_len < 0) {
                          return EINVAL;
                  }
          }
          return 0;
  }
  
  
  /*
   * sys_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
  sys_dup(proc_t p, struct dup_args *uap, int32_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 (fp_isguarded(fp, GUARD_DUP)) {
                  error = fp_guard_exception(p, old, fp, kGUARD_EXC_DUP);
                  (void) fp_drop(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, 0, retval);
  
          if (ENTR_SHOULDTRACE && FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
                  KERNEL_ENERGYTRACE(kEnTrActKernSocket, DBG_FUNC_START,
                      new, 0, (int64_t)VM_KERNEL_ADDRPERM(fp_get_data(fp)));
          }
  
          fp_drop(p, old, fp, 1);
          proc_fdunlock(p);
  
          return error;
  }
  
  /*
   * sys_dup2
   *
   * Description: Duplicate a file descriptor to a particular value.
   *
   * Parameters:  p                               Process performing the dup
   *              uap->from                       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
  sys_dup2(proc_t p, struct dup2_args *uap, int32_t *retval)
  {
          return dup2(p, uap->from, uap->to, retval);
  }
  
  int
  dup2(proc_t p, int old, int new, int *retval)
  {
          struct filedesc *fdp = &p->p_fd;
          struct fileproc *fp, *nfp;
          int i, error;
  
          proc_fdlock(p);
  
  startover:
          if ((error = fp_lookup(p, old, &fp, 1))) {
                  proc_fdunlock(p);
                  return error;
          }
          if (fp_isguarded(fp, GUARD_DUP)) {
                  error = fp_guard_exception(p, old, fp, kGUARD_EXC_DUP);
                  (void) fp_drop(p, old, fp, 1);
                  proc_fdunlock(p);
                  return error;
          }
          if (new < 0 || new >= proc_limitgetcur_nofile(p)) {
                  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:
                  if ((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 ((nfp = fdp->fd_ofiles[new]) != NULL) {
                          if (fp_isguarded(nfp, GUARD_CLOSE)) {
                                  fp_drop(p, old, fp, 1);
                                  error = fp_guard_exception(p,
                                      new, nfp, kGUARD_EXC_CLOSE);
                                  proc_fdunlock(p);
                                  return error;
                          }
                          (void)fp_close_and_unlock(p, new, nfp, FD_DUP2RESV);
                          proc_fdlock(p);
                          assert(fdp->fd_ofileflags[new] & UF_RESERVED);
                  } else {
  #if DIAGNOSTIC
                          if (fdp->fd_ofiles[new] != NULL) {
                                  panic("dup2: no ref on fileproc %d", new);
                          }
  #endif
                          procfdtbl_reservefd(p, new);
                  }
          }
  #if DIAGNOSTIC
          if (fdp->fd_ofiles[new] != 0) {
                  panic("dup2: overwriting fd_ofiles with new %d", new);
          }
          if ((fdp->fd_ofileflags[new] & UF_RESERVED) == 0) {
                  panic("dup2: unreserved fileflags with new %d", new);
          }
  #endif
          error = finishdup(p, fdp, old, new, 0, 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
  sys_fcntl(proc_t p, struct fcntl_args *uap, int32_t *retval)
  {
          __pthread_testcancel(1);
          return sys_fcntl_nocancel(p, (struct fcntl_nocancel_args *)uap, retval);
  }
  
  #define ACCOUNT_OPENFROM_ENTITLEMENT \
          "com.apple.private.vfs.role-account-openfrom"
  
  /*
   * sys_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:???
   *      msleep:ETIMEDOUT
   * [F_GETLK]
   *              EBADF
   *              EOVERFLOW
   *      copyin:EFAULT
   *      copyout:EFAULT
   *      vnode_getwithref:???
   *      VNOP_ADVLOCK:???
   * [F_PREALLOCATE]
   *              EBADF
   *              EFBIG
   *              EINVAL
   *              ENOSPC
   *      copyin:EFAULT
   *      copyout:EFAULT
   *      vnode_getwithref:???
   *      VNOP_ALLOCATE:???
   * [F_SETSIZE,F_RDADVISE]
   *              EBADF
   *              EINVAL
   *      copyin:EFAULT
   *      vnode_getwithref:???
   * [F_RDAHEAD,F_NOCACHE]
   *              EBADF
   *      vnode_getwithref:???
   * [???]
   *
   * Implicit returns:
   *              *retval (modified)              fcntl return value (if any)
   */
  #define SYS_FCNTL_DECLARE_VFS_CONTEXT(context) \
          struct vfs_context context = { \
              .vc_thread = current_thread(), \
              .vc_ucred = fp->f_cred, \
          }
  
  static user_addr_t
  sys_fnctl_parse_arg(proc_t p, user_long_t arg)
  {
          /*
           * 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
           */
          return proc_is64bit(p) ? arg : CAST_USER_ADDR_T((uint32_t)arg);
  }
  
  /* cleanup code common to fnctl functions, for when the fdlock is still held */
  static int
  sys_fcntl_out(proc_t p, int fd, struct fileproc *fp, int error)
  {
          fp_drop(p, fd, fp, 1);
          proc_fdunlock(p);
          return error;
  }
  
  /* cleanup code common to fnctl acting on vnodes, once they unlocked the fdlock */
  static int
  sys_fcntl_outdrop(proc_t p, int fd, struct fileproc *fp, struct vnode *vp, int error)
  {
  #pragma unused(vp)
  
          AUDIT_ARG(vnpath_withref, vp, ARG_VNODE1);
          fp_drop(p, fd, fp, 0);
          return error;
  }
  
  typedef int (*sys_fnctl_handler_t)(proc_t p, int fd, int cmd, user_long_t arg,
      struct fileproc *fp, int32_t *retval);
  
  typedef int (*sys_fnctl_vnode_handler_t)(proc_t p, int fd, int cmd,
      user_long_t arg, struct fileproc *fp, struct vnode *vp, int32_t *retval);
  
  /*
   * SPI (private) for opening a file starting from a dir fd
   *
   * Note: do not inline to keep stack usage under control.
   */
  __attribute__((noinline))
  static int
  sys_fcntl__OPENFROM(proc_t p, int fd, int cmd, user_long_t arg,
      struct fileproc *fp, struct vnode *vp, int32_t *retval)
  {
  #pragma unused(cmd)
  
          user_addr_t argp = sys_fnctl_parse_arg(p, arg);
          struct user_fopenfrom fopen;
          struct vnode_attr *va;
          struct nameidata *nd;
          int error, cmode;
          bool has_entitlement;
  
          /* Check if this isn't a valid file descriptor */
          if ((fp->f_flag & FREAD) == 0) {
                  return sys_fcntl_out(p, fd, fp, EBADF);
          }
          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;
          }
  
          /*
           * Only entitled apps may use the credentials of the thread
           * that opened the file descriptor.
           * Non-entitled threads will use their own context.
           */
          has_entitlement = IOCurrentTaskHasEntitlement(ACCOUNT_OPENFROM_ENTITLEMENT);
  
          /* Get flags, mode and pathname arguments. */
          if (IS_64BIT_PROCESS(p)) {
                  error = copyin(argp, &fopen, sizeof(fopen));
          } else {
                  struct user32_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;
          }
  
          /* open1() can have really deep stacks, so allocate those */
          va = kalloc_type(struct vnode_attr, Z_WAITOK | Z_ZERO | Z_NOFAIL);
          nd = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
  
          AUDIT_ARG(fflags, fopen.o_flags);
          AUDIT_ARG(mode, fopen.o_mode);
          VATTR_INIT(va);
          /* Mask off all but regular access permissions */
          cmode = ((fopen.o_mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
          VATTR_SET(va, va_mode, cmode & ACCESSPERMS);
  
          SYS_FCNTL_DECLARE_VFS_CONTEXT(context);
  
          /* Start the lookup relative to the file descriptor's vnode. */
          NDINIT(nd, LOOKUP, OP_OPEN, USEDVP | FOLLOW | AUDITVNPATH1, UIO_USERSPACE,
              fopen.o_pathname, has_entitlement ? &context : vfs_context_current());
          nd->ni_dvp = vp;
  
          error = open1(has_entitlement ? &context : vfs_context_current(),
              nd, fopen.o_flags, va, NULL, NULL, retval, AUTH_OPEN_NOAUTHFD);
  
          kfree_type(struct vnode_attr, va);
          kfree_type(struct nameidata, nd);
  
          vnode_put(vp);
  
  outdrop:
          return sys_fcntl_outdrop(p, fd, fp, vp, error);
  }
  
  int
  sys_fcntl_nocancel(proc_t p, struct fcntl_nocancel_args *uap, int32_t *retval)
  {
          int fd = uap->fd;
          int cmd = uap->cmd;
          struct filedesc *fdp = &p->p_fd;
          struct fileproc *fp;
          struct vnode *vp = NULLVP;      /* for AUDIT_ARG() at end */
          unsigned int oflags, nflags;
          int i, tmp, error, error2, flg = 0;
          struct flock fl = {};
          struct flocktimeout fltimeout;
          struct timespec *timeout = NULL;
          off_t offset;
          int newmin;
          daddr64_t lbn, bn;
          unsigned int fflag;
          user_addr_t argp;
          boolean_t is64bit;
          int has_entitlement = 0;
  
          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;
          }
  
          SYS_FCNTL_DECLARE_VFS_CONTEXT(context);
  
          is64bit = proc_is64bit(p);
          if (is64bit) {
                  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((uint32_t)uap->arg);
          }
  
  #if CONFIG_MACF
          error = mac_file_check_fcntl(kauth_cred_get(), fp->fp_glob, cmd, uap->arg);
          if (error) {
                  goto out;
          }
  #endif
  
          switch (cmd) {
          case F_DUPFD:
          case F_DUPFD_CLOEXEC:
                  if (fp_isguarded(fp, GUARD_DUP)) {
                          error = fp_guard_exception(p, fd, fp, kGUARD_EXC_DUP);
                          goto out;
                  }
                  newmin = CAST_DOWN_EXPLICIT(int, uap->arg); /* arg is an int, so we won't lose bits */
                  AUDIT_ARG(value32, newmin);
                  if (newmin < 0 || newmin >= proc_limitgetcur_nofile(p)) {
                          error = EINVAL;
                          goto out;
                  }
                  if ((error = fdalloc(p, newmin, &i))) {
                          goto out;
                  }
                  error = finishdup(p, fdp, fd, i,
                      cmd == F_DUPFD_CLOEXEC ? FP_CLOEXEC : 0, retval);
                  goto out;
  
          case F_GETFD:
                  *retval = (fp->fp_flags & FP_CLOEXEC) ? FD_CLOEXEC : 0;
                  error = 0;
                  goto out;
  
          case F_SETFD:
                  AUDIT_ARG(value32, (uint32_t)uap->arg);
                  if (uap->arg & FD_CLOEXEC) {
                          fp->fp_flags |= FP_CLOEXEC;
                          error = 0;
                  } else if (!fp->fp_guard_attrs) {
                          fp->fp_flags &= ~FP_CLOEXEC;
                          error = 0;
                  } else {
                          error = fp_guard_exception(p,
                              fd, fp, kGUARD_EXC_NOCLOEXEC);
                  }
                  goto out;
  
          case F_GETFL:
                  fflag = fp->f_flag;
                  if ((fflag & O_EVTONLY) && proc_disallow_rw_for_o_evtonly(p)) {
                          /*
                           * We insert back F_READ so that conversion back to open flags with
                           * OFLAGS() will come out right. We only need to set 'FREAD' as the
                           * 'O_RDONLY' is always implied.
                           */
                          fflag |= FREAD;
                  }
                  *retval = OFLAGS(fflag);
                  error = 0;
                  goto out;
  
          case F_SETFL:
                  // FIXME (rdar://54898652)
                  //
                  // this code is broken if fnctl(F_SETFL), ioctl() are
                  // called concurrently for the same fileglob.
  
                  tmp = CAST_DOWN_EXPLICIT(int, uap->arg); /* arg is an int, so we won't lose bits */
                  AUDIT_ARG(value32, tmp);
  
                  os_atomic_rmw_loop(&fp->f_flag, oflags, nflags, relaxed, {
                          nflags  = oflags & ~FCNTLFLAGS;
                          nflags |= FFLAGS(tmp) & FCNTLFLAGS;
                  });
                  tmp = nflags & FNONBLOCK;
                  error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, &context);
                  if (error) {
                          goto out;
                  }
                  tmp = nflags & FASYNC;
                  error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, &context);
                  if (!error) {
                          goto out;
                  }
                  os_atomic_andnot(&fp->f_flag, FNONBLOCK, relaxed);
                  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_get_data(fp))->so_pgid;
                          error = 0;
                          goto out;
                  }
                  error = fo_ioctl(fp, TIOCGPGRP, (caddr_t)retval, &context);
                  *retval = -*retval;
                  goto out;
  
          case F_SETOWN:
                  tmp = CAST_DOWN_EXPLICIT(pid_t, uap->arg); /* arg is an int, so we won't lose bits */
                  AUDIT_ARG(value32, tmp);
                  if (fp->f_type == DTYPE_SOCKET) {
                          ((struct socket *)fp_get_data(fp))->so_pgid = tmp;
                          error = 0;
                          goto out;
                  }
                  if (fp->f_type == DTYPE_PIPE) {
                          error =  fo_ioctl(fp, 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, TIOCSPGRP, (caddr_t)&tmp, &context);
                  goto out;
  
          case F_SETNOSIGPIPE:
                  tmp = CAST_DOWN_EXPLICIT(int, uap->arg);
                  if (fp->f_type == DTYPE_SOCKET) {
  #if SOCKETS
                          error = sock_setsockopt((struct socket *)fp_get_data(fp),
                              SOL_SOCKET, SO_NOSIGPIPE, &tmp, sizeof(tmp));
  #else
                          error = EINVAL;
  #endif
                  } else {
                          struct fileglob *fg = fp->fp_glob;
  
                          lck_mtx_lock_spin(&fg->fg_lock);
                          if (tmp) {
                                  fg->fg_lflags |= FG_NOSIGPIPE;
                          } else {
                                  fg->fg_lflags &= ~FG_NOSIGPIPE;
                          }
                          lck_mtx_unlock(&fg->fg_lock);
                          error = 0;
                  }
                  goto out;
  
          case F_GETNOSIGPIPE:
                  if (fp->f_type == DTYPE_SOCKET) {
  #if SOCKETS
                          int retsize = sizeof(*retval);
                          error = sock_getsockopt((struct socket *)fp_get_data(fp),
                              SOL_SOCKET, SO_NOSIGPIPE, retval, &retsize);
  #else
                          error = EINVAL;
  #endif
                  } else {
                          *retval = (fp->fp_glob->fg_lflags & FG_NOSIGPIPE) ?
                              1 : 0;
                          error = 0;
                  }
                  goto out;
  
          case F_SETCONFINED:
                  /*
                   * If this is the only reference to this fglob in the process
                   * and it's already marked as close-on-fork then mark it as
                   * (immutably) "confined" i.e. any fd that points to it will
                   * forever be close-on-fork, and attempts to use an IPC
                   * mechanism to move the descriptor elsewhere will fail.
                   */
                  if (CAST_DOWN_EXPLICIT(int, uap->arg)) {
                          struct fileglob *fg = fp->fp_glob;
  
                          lck_mtx_lock_spin(&fg->fg_lock);
                          if (fg->fg_lflags & FG_CONFINED) {
                                  error = 0;
                          } else if (1 != os_ref_get_count_raw(&fg->fg_count)) {
                                  error = EAGAIN; /* go close the dup .. */
                          } else if (fp->fp_flags & FP_CLOFORK) {
                                  fg->fg_lflags |= FG_CONFINED;
                                  error = 0;
                          } else {
                                  error = EBADF;  /* open without O_CLOFORK? */
                          }
                          lck_mtx_unlock(&fg->fg_lock);
                  } else {
                          /*
                           * Other subsystems may have built on the immutability
                           * of FG_CONFINED; clearing it may be tricky.
                           */
                          error = EPERM;          /* immutable */
                  }
                  goto out;
  
          case F_GETCONFINED:
                  *retval = (fp->fp_glob->fg_lflags & FG_CONFINED) ? 1 : 0;
                  error = 0;
                  goto out;
  
          case F_SETLKWTIMEOUT:
          case F_SETLKW:
          case F_OFD_SETLKWTIMEOUT:
          case F_OFD_SETLKW:
                  flg |= F_WAIT;
                  OS_FALLTHROUGH;
  
          case F_SETLK:
          case F_OFD_SETLK:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
  
                  fflag = fp->f_flag;
                  offset = fp->f_offset;
                  proc_fdunlock(p);
  
                  /* Copy in the lock structure */
                  if (F_SETLKWTIMEOUT == cmd || F_OFD_SETLKWTIMEOUT == cmd) {
                          error = copyin(argp, (caddr_t) &fltimeout, sizeof(fltimeout));
                          if (error) {
                                  goto outdrop;
                          }
                          fl = fltimeout.fl;
                          timeout = &fltimeout.timeout;
                  } else {
                          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 */
                  error = check_file_seek_range(&fl, offset);
                  if (error) {
                          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(kauth_cred_get(), fp->fp_glob,
                      F_SETLK, &fl);
                  if (error) {
                          (void)vnode_put(vp);
                          goto outdrop;
                  }
  #endif
  
  #if CONFIG_FILE_LEASES
                  (void)vnode_breaklease(vp, O_WRONLY, vfs_context_current());
  #endif
  
                  switch (cmd) {
                  case F_OFD_SETLK:
                  case F_OFD_SETLKW:
                  case F_OFD_SETLKWTIMEOUT:
                          flg |= F_OFD_LOCK;
                          switch (fl.l_type) {
                          case F_RDLCK:
                                  if ((fflag & FREAD) == 0) {
                                          error = EBADF;
                                          break;
                                  }
                                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob,
                                      F_SETLK, &fl, flg, &context, timeout);
                                  break;
                          case F_WRLCK:
                                  if ((fflag & FWRITE) == 0) {
                                          error = EBADF;
                                          break;
                                  }
                                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob,
                                      F_SETLK, &fl, flg, &context, timeout);
                                  break;
                          case F_UNLCK:
                                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob,
                                      F_UNLCK, &fl, F_OFD_LOCK, &context,
                                      timeout);
                                  break;
                          default:
                                  error = EINVAL;
                                  break;
                          }
                          if (0 == error &&
                              (F_RDLCK == fl.l_type || F_WRLCK == fl.l_type)) {
                                  struct fileglob *fg = fp->fp_glob;
  
                                  /*
                                   * arrange F_UNLCK on last close (once
                                   * set, FG_HAS_OFDLOCK is immutable)
                                   */
                                  if ((fg->fg_lflags & FG_HAS_OFDLOCK) == 0) {
                                          lck_mtx_lock_spin(&fg->fg_lock);
                                          fg->fg_lflags |= FG_HAS_OFDLOCK;
                                          lck_mtx_unlock(&fg->fg_lock);
                                  }
                          }
                          break;
                  default:
                          flg |= F_POSIX;
                          switch (fl.l_type) {
                          case F_RDLCK:
                                  if ((fflag & FREAD) == 0) {
                                          error = EBADF;
                                          break;
                                  }
                                  // XXX UInt32 unsafe for LP64 kernel
                                  os_atomic_or(&p->p_ladvflag, P_LADVLOCK, relaxed);
                                  error = VNOP_ADVLOCK(vp, (caddr_t)p,
                                      F_SETLK, &fl, flg, &context, timeout);
                                  break;
                          case F_WRLCK:
                                  if ((fflag & FWRITE) == 0) {
                                          error = EBADF;
                                          break;
                                  }
                                  // XXX UInt32 unsafe for LP64 kernel
                                  os_atomic_or(&p->p_ladvflag, P_LADVLOCK, relaxed);
                                  error = VNOP_ADVLOCK(vp, (caddr_t)p,
                                      F_SETLK, &fl, flg, &context, timeout);
                                  break;
                          case F_UNLCK:
                                  error = VNOP_ADVLOCK(vp, (caddr_t)p,
                                      F_UNLCK, &fl, F_POSIX, &context, timeout);
                                  break;
                          default:
                                  error = EINVAL;
                                  break;
                          }
                          break;
                  }
                  (void) vnode_put(vp);
                  goto outdrop;
  
          case F_GETLK:
          case F_OFD_GETLK:
          case F_GETLKPID:
          case F_OFD_GETLKPID:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
  
                  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 */
                  error = check_file_seek_range(&fl, offset);
                  if (error) {
                          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(kauth_cred_get(), fp->fp_glob,
                              cmd, &fl);
                          if (error == 0)
  #endif
                          switch (cmd) {
                          case F_OFD_GETLK:
                                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob,
                                      F_GETLK, &fl, F_OFD_LOCK, &context, NULL);
                                  break;
                          case F_OFD_GETLKPID:
                                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob,
                                      F_GETLKPID, &fl, F_OFD_LOCK, &context, NULL);
                                  break;
                          default:
                                  error = VNOP_ADVLOCK(vp, (caddr_t)p,
                                      cmd, &fl, F_POSIX, &context, NULL);
                                  break;
                          }
  
                          (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_get_data(fp);
                  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;
                  }
  
                  if (alloc_struct.fst_flags & F_ALLOCATEPERSIST) {
                          alloc_flags |= ALLOCATEPERSIST;
                  }
  
                  /*
                   * 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_PUNCHHOLE: {
                  fpunchhole_t args;
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  /* need write permissions */
                  if ((fp->f_flag & FWRITE) == 0) {
                          error = EPERM;
                          goto outdrop;
                  }
  
                  if ((error = copyin(argp, (caddr_t)&args, sizeof(args)))) {
                          goto outdrop;
                  }
  
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
  
  #if CONFIG_MACF
                  if ((error = mac_vnode_check_write(&context, fp->fp_glob->fg_cred, vp))) {
                          (void)vnode_put(vp);
                          goto outdrop;
                  }
  #endif
  
                  error = VNOP_IOCTL(vp, F_PUNCHHOLE, (caddr_t)&args, 0, &context);
                  (void)vnode_put(vp);
  
                  goto outdrop;
          }
          case F_TRIM_ACTIVE_FILE: {
                  ftrimactivefile_t args;
  
                  if (priv_check_cred(kauth_cred_get(), PRIV_TRIM_ACTIVE_FILE, 0)) {
                          error = EACCES;
                          goto out;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  /* need write permissions */
                  if ((fp->f_flag & FWRITE) == 0) {
                          error = EPERM;
                          goto outdrop;
                  }
  
                  if ((error = copyin(argp, (caddr_t)&args, sizeof(args)))) {
                          goto outdrop;
                  }
  
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
  
                  error = VNOP_IOCTL(vp, F_TRIM_ACTIVE_FILE, (caddr_t)&args, 0, &context);
                  (void)vnode_put(vp);
  
                  goto outdrop;
          }
          case F_SPECULATIVE_READ: {
                  fspecread_t args;
                  off_t temp_length = 0;
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = copyin(argp, (caddr_t)&args, sizeof(args)))) {
                          goto outdrop;
                  }
  
                  /* Discard invalid offsets or lengths */
                  if ((args.fsr_offset < 0) || (args.fsr_length < 0)) {
                          error = EINVAL;
                          goto outdrop;
                  }
  
                  /*
                   * Round the file offset down to a page-size boundary (or to 0).
                   * The filesystem will need to round the length up to the end of the page boundary
                   * or to the EOF of the file.
                   */
                  uint64_t foff = (((uint64_t)args.fsr_offset) & ~((uint64_t)PAGE_MASK));
                  uint64_t foff_delta = args.fsr_offset - foff;
                  args.fsr_offset = (off_t) foff;
  
                  /*
                   * Now add in the delta to the supplied length. Since we may have adjusted the
                   * offset, increase it by the amount that we adjusted.
                   */
                  if (os_add_overflow(args.fsr_length, foff_delta, &args.fsr_length)) {
                          error = EOVERFLOW;
                          goto outdrop;
                  }
  
                  /*
                   * Make sure (fsr_offset + fsr_length) does not overflow.
                   */
                  if (os_add_overflow(args.fsr_offset, args.fsr_length, &temp_length)) {
                          error = EOVERFLOW;
                          goto outdrop;
                  }
  
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
                  error = VNOP_IOCTL(vp, F_SPECULATIVE_READ, (caddr_t)&args, 0, &context);
                  (void)vnode_put(vp);
  
                  goto outdrop;
          }
          case F_SETSIZE:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  error = copyin(argp, (caddr_t)&offset, sizeof(off_t));
                  if (error) {
                          goto outdrop;
                  }
                  AUDIT_ARG(value64, offset);
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          goto outdrop;
                  }
  
  #if CONFIG_MACF
                  error = mac_vnode_check_truncate(&context,
                      fp->fp_glob->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.
                   */
                  if (!kauth_cred_issuser(kauth_cred_get())) {
                          error = EACCES;
                  } else {
                          /*
                           * Require privilege to change file size without zerofill,
                           * else will change the file size and zerofill it.
                           */
                          error = priv_check_cred(kauth_cred_get(), PRIV_VFS_SETSIZE, 0);
                          if (error == 0) {
                                  error = vnode_setsize(vp, offset, IO_NOZEROFILL, &context);
                          } else {
                                  error = vnode_setsize(vp, offset, 0, &context);
                          }
  
  #if CONFIG_MACF
                          if (error == 0) {
                                  mac_vnode_notify_truncate(&context, fp->fp_glob->fg_cred, vp);
                          }
  #endif
                  }
  
                  (void)vnode_put(vp);
                  goto outdrop;
  
          case F_RDAHEAD:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  if (uap->arg) {
                          os_atomic_andnot(&fp->fp_glob->fg_flag, FNORDAHEAD, relaxed);
                  } else {
                          os_atomic_or(&fp->fp_glob->fg_flag, FNORDAHEAD, relaxed);
                  }
                  goto out;
  
          case F_NOCACHE:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  if (uap->arg) {
                          os_atomic_or(&fp->fp_glob->fg_flag, FNOCACHE, relaxed);
                  } else {
                          os_atomic_andnot(&fp->fp_glob->fg_flag, FNOCACHE, relaxed);
                  }
                  goto out;
  
          case F_NODIRECT:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  if (uap->arg) {
                          os_atomic_or(&fp->fp_glob->fg_flag, FNODIRECT, relaxed);
                  } else {
                          os_atomic_andnot(&fp->fp_glob->fg_flag, FNODIRECT, relaxed);
                  }
                  goto out;
  
          case F_SINGLE_WRITER:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  if (uap->arg) {
                          os_atomic_or(&fp->fp_glob->fg_flag, FSINGLE_WRITER, relaxed);
                  } else {
                          os_atomic_andnot(&fp->fp_glob->fg_flag, FSINGLE_WRITER, relaxed);
                  }
                  goto out;
  
          case F_GLOBAL_NOCACHE:
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  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_get_data(fp);
                  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_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = copyin(argp, (caddr_t)&ra_struct, sizeof(ra_struct)))) {
                          goto outdrop;
                  }
                  if (ra_struct.ra_offset < 0 || ra_struct.ra_count < 0) {
                          error = EINVAL;
                          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_FLUSH_DATA:
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = vnode_getwithref(vp)) == 0) {
                          error = VNOP_FSYNC(vp, MNT_NOWAIT, &context);
  
                          (void)vnode_put(vp);
                  }
                  goto outdrop;
  
          case F_LOG2PHYS:
          case F_LOG2PHYS_EXT: {
                  struct log2phys l2p_struct = {};    /* structure for allocate command */
                  int devBlockSize;
  
                  off_t file_offset = 0;
                  size_t a_size = 0;
                  size_t run = 0;
  
                  if (cmd == F_LOG2PHYS_EXT) {
                          error = copyin(argp, (caddr_t)&l2p_struct, sizeof(l2p_struct));
                          if (error) {
                                  goto out;
                          }
                          file_offset = l2p_struct.l2p_devoffset;
                  } else {
                          file_offset = fp->f_offset;
                  }
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
                  error = VNOP_OFFTOBLK(vp, file_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));
                  if (cmd == F_LOG2PHYS_EXT) {
                          if (l2p_struct.l2p_contigbytes < 0) {
                                  vnode_put(vp);
                                  error = EINVAL;
                                  goto outdrop;
                          }
  
                          a_size = (size_t)MIN((uint64_t)l2p_struct.l2p_contigbytes, SIZE_MAX);
                  } else {
                          a_size = devBlockSize;
                  }
  
                  error = VNOP_BLOCKMAP(vp, offset, a_size, &bn, &run, NULL, 0, &context);
  
                  (void)vnode_put(vp);
  
                  if (!error) {
                          l2p_struct.l2p_flags = 0;       /* for now */
                          if (cmd == F_LOG2PHYS_EXT) {
                                  l2p_struct.l2p_contigbytes = run - (file_offset - offset);
                          } else {
                                  l2p_struct.l2p_contigbytes = 0; /* for now */
                          }
  
                          /*
                           * The block number being -1 suggests that the file offset is not backed
                           * by any real blocks on-disk.  As a result, just let it be passed back up wholesale.
                           */
                          if (bn == -1) {
                                  /* Don't multiply it by the block size */
                                  l2p_struct.l2p_devoffset = bn;
                          } else {
                                  l2p_struct.l2p_devoffset = bn * devBlockSize;
                                  l2p_struct.l2p_devoffset += file_offset - offset;
                          }
                          error = copyout((caddr_t)&l2p_struct, argp, sizeof(l2p_struct));
                  }
                  goto outdrop;
          }
          case F_GETPATH:
          case F_GETPATH_NOFIRMLINK: {
                  char *pathbufp;
                  size_t pathlen;
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  pathlen = MAXPATHLEN;
                  pathbufp = zalloc(ZV_NAMEI);
  
                  if ((error = vnode_getwithref(vp)) == 0) {
                          error = vn_getpath_ext(vp, NULL, pathbufp,
                              &pathlen, cmd == F_GETPATH_NOFIRMLINK ?
                              VN_GETPATH_NO_FIRMLINK : 0);
                          (void)vnode_put(vp);
  
                          if (error == 0) {
                                  error = copyout((caddr_t)pathbufp, argp, pathlen);
                          }
                  }
                  zfree(ZV_NAMEI, pathbufp);
                  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_get_data(fp);
                  proc_fdunlock(p);
  
                  pathlen = MAXPATHLEN;
                  pathbufp = zalloc(ZV_NAMEI);
  
                  if ((error = copyinstr(argp, pathbufp, MAXPATHLEN, &pathlen)) == 0) {
                          if ((error = vnode_getwithref(vp)) == 0) {
                                  AUDIT_ARG(text, pathbufp);
                                  error = vn_path_package_check(vp, pathbufp, (int)pathlen, retval);
  
                                  (void)vnode_put(vp);
                          }
                  }
                  zfree(ZV_NAMEI, pathbufp);
                  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 + DKIOCSYNCHRONIZE
          case F_BARRIERFSYNC:  // fsync + barrier
          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_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = vnode_getwithref(vp)) == 0) {
                          error = VNOP_IOCTL(vp, 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: {
                  /* Check if this isn't a valid file descriptor */
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
  
                  return sys_fcntl__OPENFROM(p, fd, cmd, uap->arg, fp, vp, retval);
          }
  
          /*
           * SPI (private) for unlinking a file starting from a dir fd
           */
          case F_UNLINKFROM: {
                  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_get_data(fp);
                  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;
                  }
  
                  /*
                   * Only entitled apps may use the credentials of the thread
                   * that opened the file descriptor.
                   * Non-entitled threads will use their own context.
                   */
                  if (IOCurrentTaskHasEntitlement(ACCOUNT_OPENFROM_ENTITLEMENT)) {
                          has_entitlement = 1;
                  }
  
                  /* 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. */
                  error = unlink1(has_entitlement ? &context : vfs_context_current(),
                      vp, pathname, UIO_USERSPACE, 0);
  
                  vnode_put(vp);
                  break;
          }
  
          case F_ADDSIGS:
          case F_ADDFILESIGS:
          case F_ADDFILESIGS_FOR_DYLD_SIM:
          case F_ADDFILESIGS_RETURN:
          case F_ADDFILESIGS_INFO:
          {
                  struct cs_blob *blob = NULL;
                  struct user_fsignatures fs;
                  kern_return_t kr;
                  vm_offset_t kernel_blob_addr;
                  vm_size_t kernel_blob_size;
                  int blob_add_flags = 0;
                  const size_t sizeof_fs = (cmd == F_ADDFILESIGS_INFO ?
                      offsetof(struct user_fsignatures, fs_cdhash /* first output element */) :
                      offsetof(struct user_fsignatures, fs_fsignatures_size /* compat */));
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if (cmd == F_ADDFILESIGS_FOR_DYLD_SIM) {
                          blob_add_flags |= MAC_VNODE_CHECK_DYLD_SIM;
                          if ((proc_getcsflags(p) & CS_KILL) == 0) {
                                  proc_lock(p);
                                  proc_csflags_set(p, CS_KILL);
                                  proc_unlock(p);
                          }
                  }
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          goto outdrop;
                  }
  
                  if (IS_64BIT_PROCESS(p)) {
                          error = copyin(argp, &fs, sizeof_fs);
                  } else {
                          if (cmd == F_ADDFILESIGS_INFO) {
                                  error = EINVAL;
                                  vnode_put(vp);
                                  goto outdrop;
                          }
  
                          struct user32_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;
                  }
  
                  /*
                   * First check if we have something loaded a this offset
                   */
                  blob = ubc_cs_blob_get(vp, CPU_TYPE_ANY, CPU_SUBTYPE_ANY, fs.fs_file_start);
                  if (blob != NULL) {
                          /* If this is for dyld_sim revalidate the blob */
                          if (cmd == F_ADDFILESIGS_FOR_DYLD_SIM) {
                                  error = ubc_cs_blob_revalidate(vp, blob, NULL, blob_add_flags, proc_platform(p));
                                  if (error) {
                                          blob = NULL;
                                          if (error != EAGAIN) {
                                                  vnode_put(vp);
                                                  goto outdrop;
                                          }
                                  }
                          }
                  }
  
                  if (blob == NULL) {
                          /*
                           * An arbitrary limit, to prevent someone from mapping in a 20GB blob.  This should cover
                           * our use cases for the immediate future, but note that at the time of this commit, some
                           * platforms are nearing 2MB blob sizes (with a prior soft limit of 2.5MB).
                           *
                           * We should consider how we can manage this more effectively; the above means that some
                           * platforms are using megabytes of memory for signing data; it merely hasn't crossed the
                           * threshold considered ridiculous at the time of this change.
                           */
  #define CS_MAX_BLOB_SIZE (40ULL * 1024ULL * 1024ULL)
                          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 || kernel_blob_size < fs.fs_blob_size) {
                                  error = ENOMEM;
                                  vnode_put(vp);
                                  goto outdrop;
                          }
  
                          if (cmd == F_ADDSIGS) {
                                  error = copyin(fs.fs_blob_start,
                                      (void *) kernel_blob_addr,
                                      fs.fs_blob_size);
                          } else { /* F_ADDFILESIGS || F_ADDFILESIGS_RETURN || F_ADDFILESIGS_FOR_DYLD_SIM || F_ADDFILESIGS_INFO */
                                  int resid;
  
                                  error = vn_rdwr(UIO_READ,
                                      vp,
                                      (caddr_t) kernel_blob_addr,
                                      (int)kernel_blob_size,
                                      fs.fs_file_start + fs.fs_blob_start,
                                      UIO_SYSSPACE,
                                      0,
                                      kauth_cred_get(),
                                      &resid,
                                      p);
                                  if ((error == 0) && resid) {
                                          /* kernel_blob_size rounded to a page size, but signature may be at end of file */
                                          memset((void *)(kernel_blob_addr + (kernel_blob_size - resid)), 0x0, resid);
                                  }
                          }
  
                          if (error) {
                                  ubc_cs_blob_deallocate(kernel_blob_addr,
                                      kernel_blob_size);
                                  vnode_put(vp);
                                  goto outdrop;
                          }
  
                          blob = NULL;
                          error = ubc_cs_blob_add(vp,
                              proc_platform(p),
                              CPU_TYPE_ANY,                       /* not for a specific architecture */
                              CPU_SUBTYPE_ANY,
                              fs.fs_file_start,
                              &kernel_blob_addr,
                              kernel_blob_size,
                              NULL,
                              blob_add_flags,
                              &blob);
  
                          /* ubc_blob_add() has consumed "kernel_blob_addr" if it is zeroed */
                          if (error) {
                                  if (kernel_blob_addr) {
                                          ubc_cs_blob_deallocate(kernel_blob_addr,
                                              kernel_blob_size);
                                  }
                                  vnode_put(vp);
                                  goto outdrop;
                          } else {
  #if CHECK_CS_VALIDATION_BITMAP
                                  ubc_cs_validation_bitmap_allocate( vp );
  #endif
                          }
                  }
  
                  if (cmd == F_ADDFILESIGS_RETURN || cmd == F_ADDFILESIGS_FOR_DYLD_SIM ||
                      cmd == F_ADDFILESIGS_INFO) {
                          /*
                           * The first element of the structure is a
                           * off_t that happen to have the same size for
                           * all archs. Lets overwrite that.
                           */
                          off_t end_offset = 0;
                          if (blob) {
                                  end_offset = blob->csb_end_offset;
                          }
                          error = copyout(&end_offset, argp, sizeof(end_offset));
  
                          if (error) {
                                  vnode_put(vp);
                                  goto outdrop;
                          }
                  }
  
                  if (cmd == F_ADDFILESIGS_INFO) {
                          /* Return information. What we copy out depends on the size of the
                           * passed in structure, to keep binary compatibility. */
  
                          if (fs.fs_fsignatures_size >= sizeof(struct user_fsignatures)) {
                                  // enough room for fs_cdhash[20]+fs_hash_type
  
                                  if (blob != NULL) {
                                          error = copyout(blob->csb_cdhash,
                                              (vm_address_t)argp + offsetof(struct user_fsignatures, fs_cdhash),
                                              USER_FSIGNATURES_CDHASH_LEN);
                                          if (error) {
                                                  vnode_put(vp);
                                                  goto outdrop;
                                          }
                                          int hashtype = cs_hash_type(blob->csb_hashtype);
                                          error = copyout(&hashtype,
                                              (vm_address_t)argp + offsetof(struct user_fsignatures, fs_hash_type),
                                              sizeof(int));
                                          if (error) {
                                                  vnode_put(vp);
                                                  goto outdrop;
                                          }
                                  }
                          }
                  }
  
                  (void) vnode_put(vp);
                  break;
          }
  #if CONFIG_SUPPLEMENTAL_SIGNATURES
          case F_ADDFILESUPPL:
          {
                  struct vnode *ivp;
                  struct cs_blob *blob = NULL;
                  struct user_fsupplement fs;
                  int orig_fd;
                  struct fileproc* orig_fp = NULL;
                  kern_return_t kr;
                  vm_offset_t kernel_blob_addr;
                  vm_size_t kernel_blob_size;
  
                  if (!IS_64BIT_PROCESS(p)) {
                          error = EINVAL;
                          goto out; // drop fp and unlock fds
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  error = copyin(argp, &fs, sizeof(fs));
                  if (error) {
                          goto out;
                  }
  
                  orig_fd = fs.fs_orig_fd;
                  if ((error = fp_lookup(p, orig_fd, &orig_fp, 1))) {
                          printf("CODE SIGNING: Failed to find original file for supplemental signature attachment\n");
                          goto out;
                  }
  
                  if (orig_fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          fp_drop(p, orig_fd, orig_fp, 1);
                          goto out;
                  }
  
                  ivp = (struct vnode *)fp_get_data(orig_fp);
  
                  vp = (struct vnode *)fp_get_data(fp);
  
                  proc_fdunlock(p);
  
                  error = vnode_getwithref(ivp);
                  if (error) {
                          fp_drop(p, orig_fd, orig_fp, 0);
                          goto outdrop; //drop fp
                  }
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          vnode_put(ivp);
                          fp_drop(p, orig_fd, orig_fp, 0);
                          goto outdrop;
                  }
  
                  if (fs.fs_blob_size > CS_MAX_BLOB_SIZE) {
                          error = E2BIG;
                          goto dropboth; // drop iocounts on vp and ivp, drop orig_fp then drop fp via 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;
                          goto dropboth;
                  }
  
                  int resid;
                  error = vn_rdwr(UIO_READ, vp,
                      (caddr_t)kernel_blob_addr, (int)kernel_blob_size,
                      fs.fs_file_start + fs.fs_blob_start,
                      UIO_SYSSPACE, 0,
                      kauth_cred_get(), &resid, p);
                  if ((error == 0) && resid) {
                          /* kernel_blob_size rounded to a page size, but signature may be at end of file */
                          memset((void *)(kernel_blob_addr + (kernel_blob_size - resid)), 0x0, resid);
                  }
  
                  if (error) {
                          ubc_cs_blob_deallocate(kernel_blob_addr,
                              kernel_blob_size);
                          goto dropboth;
                  }
  
                  error = ubc_cs_blob_add_supplement(vp, ivp, fs.fs_file_start,
                      &kernel_blob_addr, kernel_blob_size, &blob);
  
                  /* ubc_blob_add_supplement() has consumed kernel_blob_addr if it is zeroed */
                  if (error) {
                          if (kernel_blob_addr) {
                                  ubc_cs_blob_deallocate(kernel_blob_addr,
                                      kernel_blob_size);
                          }
                          goto dropboth;
                  }
                  vnode_put(ivp);
                  vnode_put(vp);
                  fp_drop(p, orig_fd, orig_fp, 0);
                  break;
  
  dropboth:
                  vnode_put(ivp);
                  vnode_put(vp);
                  fp_drop(p, orig_fd, orig_fp, 0);
                  goto outdrop;
          }
  #endif
          case F_GETCODEDIR:
          case F_FINDSIGS: {
                  error = ENOTSUP;
                  goto out;
          }
          case F_CHECK_LV: {
                  struct fileglob *fg;
                  fchecklv_t lv = {};
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  fg = fp->fp_glob;
                  proc_fdunlock(p);
  
                  if (IS_64BIT_PROCESS(p)) {
                          error = copyin(argp, &lv, sizeof(lv));
                  } else {
                          struct user32_fchecklv lv32 = {};
  
                          error = copyin(argp, &lv32, sizeof(lv32));
                          lv.lv_file_start = lv32.lv_file_start;
                          lv.lv_error_message = (void *)(uintptr_t)lv32.lv_error_message;
                          lv.lv_error_message_size = lv32.lv_error_message_size;
                  }
                  if (error) {
                          goto outdrop;
                  }
  
  #if CONFIG_MACF
                  error = mac_file_check_library_validation(p, fg, lv.lv_file_start,
                      (user_long_t)lv.lv_error_message, lv.lv_error_message_size);
  #endif
  
                  break;
          }
          case F_GETSIGSINFO: {
                  struct cs_blob *blob = NULL;
                  fgetsigsinfo_t sigsinfo = {};
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          goto outdrop;
                  }
  
                  error = copyin(argp, &sigsinfo, sizeof(sigsinfo));
                  if (error) {
                          vnode_put(vp);
                          goto outdrop;
                  }
  
                  blob = ubc_cs_blob_get(vp, CPU_TYPE_ANY, CPU_SUBTYPE_ANY, sigsinfo.fg_file_start);
                  if (blob == NULL) {
                          error = ENOENT;
                          vnode_put(vp);
                          goto outdrop;
                  }
                  switch (sigsinfo.fg_info_request) {
                  case GETSIGSINFO_PLATFORM_BINARY:
                          sigsinfo.fg_sig_is_platform = blob->csb_platform_binary;
                          error = copyout(&sigsinfo.fg_sig_is_platform,
                              (vm_address_t)argp + offsetof(struct fgetsigsinfo, fg_sig_is_platform),
                              sizeof(sigsinfo.fg_sig_is_platform));
                          if (error) {
                                  vnode_put(vp);
                                  goto outdrop;
                          }
                          break;
                  default:
                          error = EINVAL;
                          vnode_put(vp);
                          goto outdrop;
                  }
                  vnode_put(vp);
                  break;
          }
  #if CONFIG_PROTECT
          case F_GETPROTECTIONCLASS: {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
  
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  struct vnode_attr va;
  
                  VATTR_INIT(&va);
                  VATTR_WANTED(&va, va_dataprotect_class);
                  error = VNOP_GETATTR(vp, &va, &context);
                  if (!error) {
                          if (VATTR_IS_SUPPORTED(&va, va_dataprotect_class)) {
                                  *retval = va.va_dataprotect_class;
                          } else {
                                  error = ENOTSUP;
                          }
                  }
  
                  vnode_put(vp);
                  break;
          }
  
          case F_SETPROTECTIONCLASS: {
                  /* tmp must be a valid PROTECTION_CLASS_* */
                  tmp = CAST_DOWN_EXPLICIT(uint32_t, uap->arg);
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
  
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* Only go forward if you have write access */
                  vfs_context_t ctx = vfs_context_current();
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), ctx) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  struct vnode_attr va;
  
                  VATTR_INIT(&va);
                  VATTR_SET(&va, va_dataprotect_class, tmp);
  
                  error = VNOP_SETATTR(vp, &va, ctx);
  
                  vnode_put(vp);
                  break;
          }
  
          case F_TRANSCODEKEY: {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  cp_key_t k = {
                          .len = CP_MAX_WRAPPEDKEYSIZE,
                  };
  
                  k.key = kalloc_data(CP_MAX_WRAPPEDKEYSIZE, Z_WAITOK | Z_ZERO);
                  if (k.key == NULL) {
                          error = ENOMEM;
                  } else {
                          error = VNOP_IOCTL(vp, F_TRANSCODEKEY, (caddr_t)&k, 1, &context);
                  }
  
                  vnode_put(vp);
  
                  if (error == 0) {
                          error = copyout(k.key, argp, k.len);
                          *retval = k.len;
                  }
                  kfree_data(k.key, CP_MAX_WRAPPEDKEYSIZE);
  
                  break;
          }
  
          case F_GETPROTECTIONLEVEL:  {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode*)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  error = VNOP_IOCTL(vp, F_GETPROTECTIONLEVEL, (caddr_t)retval, 0, &context);
  
                  vnode_put(vp);
                  break;
          }
  
          case F_GETDEFAULTPROTLEVEL:  {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode*)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /*
                   * if cp_get_major_vers fails, error will be set to proper errno
                   * and cp_version will still be 0.
                   */
  
                  error = VNOP_IOCTL(vp, F_GETDEFAULTPROTLEVEL, (caddr_t)retval, 0, &context);
  
                  vnode_put(vp);
                  break;
          }
  
  #endif /* CONFIG_PROTECT */
  
          case F_MOVEDATAEXTENTS: {
                  struct fileproc *fp2 = NULL;
                  struct vnode *src_vp = NULLVP;
                  struct vnode *dst_vp = NULLVP;
                  /* We need to grab the 2nd FD out of the arguments before moving on. */
                  int fd2 = CAST_DOWN_EXPLICIT(int32_t, uap->arg);
  
                  error = priv_check_cred(kauth_cred_get(), PRIV_VFS_MOVE_DATA_EXTENTS, 0);
                  if (error) {
                          goto out;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  /*
                   * For now, special case HFS+ and APFS only, since this
                   * is SPI.
                   */
                  src_vp = (struct vnode *)fp_get_data(fp);
                  if (src_vp->v_tag != VT_HFS && src_vp->v_tag != VT_APFS) {
                          error = ENOTSUP;
                          goto out;
                  }
  
                  /*
                   * Get the references before we start acquiring iocounts on the vnodes,
                   * while we still hold the proc fd lock
                   */
                  if ((error = fp_lookup(p, fd2, &fp2, 1))) {
                          error = EBADF;
                          goto out;
                  }
                  if (fp2->f_type != DTYPE_VNODE) {
                          fp_drop(p, fd2, fp2, 1);
                          error = EBADF;
                          goto out;
                  }
                  dst_vp = (struct vnode *)fp_get_data(fp2);
                  if (dst_vp->v_tag != VT_HFS && dst_vp->v_tag != VT_APFS) {
                          fp_drop(p, fd2, fp2, 1);
                          error = ENOTSUP;
                          goto out;
                  }
  
  #if CONFIG_MACF
                  /* Re-do MAC checks against the new FD, pass in a fake argument */
                  error = mac_file_check_fcntl(kauth_cred_get(), fp2->fp_glob, cmd, 0);
                  if (error) {
                          fp_drop(p, fd2, fp2, 1);
                          goto out;
                  }
  #endif
                  /* Audit the 2nd FD */
                  AUDIT_ARG(fd, fd2);
  
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(src_vp)) {
                          fp_drop(p, fd2, fp2, 0);
                          error = ENOENT;
                          goto outdrop;
                  }
                  if (vnode_getwithref(dst_vp)) {
                          vnode_put(src_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /*
                   * Basic asserts; validate they are not the same and that
                   * both live on the same filesystem.
                   */
                  if (dst_vp == src_vp) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EINVAL;
                          goto outdrop;
                  }
  
                  if (dst_vp->v_mount != src_vp->v_mount) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EXDEV;
                          goto outdrop;
                  }
  
                  /* Now we have a legit pair of FDs.  Go to work */
  
                  /* Now check for write access to the target files */
                  if (vnode_authorize(src_vp, NULLVP,
                      (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), &context) != 0) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  if (vnode_authorize(dst_vp, NULLVP,
                      (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), &context) != 0) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  /* Verify that both vps point to files and not directories */
                  if (!vnode_isreg(src_vp) || !vnode_isreg(dst_vp)) {
                          error = EINVAL;
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          goto outdrop;
                  }
  
                  /*
                   * The exchangedata syscall handler passes in 0 for the flags to VNOP_EXCHANGE.
                   * We'll pass in our special bit indicating that the new behavior is expected
                   */
  
                  error = VNOP_EXCHANGE(src_vp, dst_vp, FSOPT_EXCHANGE_DATA_ONLY, &context);
  
                  vnode_put(src_vp);
                  vnode_put(dst_vp);
                  fp_drop(p, fd2, fp2, 0);
                  break;
          }
  
          case F_TRANSFEREXTENTS: {
                  struct fileproc *fp2 = NULL;
                  struct vnode *src_vp = NULLVP;
                  struct vnode *dst_vp = NULLVP;
  
                  /* Get 2nd FD out of the arguments. */
                  int fd2 = CAST_DOWN_EXPLICIT(int, uap->arg);
                  if (fd2 < 0) {
                          error = EINVAL;
                          goto out;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  /*
                   * Only allow this for APFS
                   */
                  src_vp = (struct vnode *)fp_get_data(fp);
                  if (src_vp->v_tag != VT_APFS) {
                          error = ENOTSUP;
                          goto out;
                  }
  
                  /*
                   * Get the references before we start acquiring iocounts on the vnodes,
                   * while we still hold the proc fd lock
                   */
                  if ((error = fp_lookup(p, fd2, &fp2, 1))) {
                          error = EBADF;
                          goto out;
                  }
                  if (fp2->f_type != DTYPE_VNODE) {
                          fp_drop(p, fd2, fp2, 1);
                          error = EBADF;
                          goto out;
                  }
                  dst_vp = (struct vnode *)fp_get_data(fp2);
                  if (dst_vp->v_tag != VT_APFS) {
                          fp_drop(p, fd2, fp2, 1);
                          error = ENOTSUP;
                          goto out;
                  }
  
  #if CONFIG_MACF
                  /* Re-do MAC checks against the new FD, pass in a fake argument */
                  error = mac_file_check_fcntl(kauth_cred_get(), fp2->fp_glob, cmd, 0);
                  if (error) {
                          fp_drop(p, fd2, fp2, 1);
                          goto out;
                  }
  #endif
                  /* Audit the 2nd FD */
                  AUDIT_ARG(fd, fd2);
  
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(src_vp)) {
                          fp_drop(p, fd2, fp2, 0);
                          error = ENOENT;
                          goto outdrop;
                  }
                  if (vnode_getwithref(dst_vp)) {
                          vnode_put(src_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /*
                   * Validate they are not the same and that
                   * both live on the same filesystem.
                   */
                  if (dst_vp == src_vp) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EINVAL;
                          goto outdrop;
                  }
                  if (dst_vp->v_mount != src_vp->v_mount) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EXDEV;
                          goto outdrop;
                  }
  
                  /* Verify that both vps point to files and not directories */
                  if (!vnode_isreg(src_vp) || !vnode_isreg(dst_vp)) {
                          error = EINVAL;
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          goto outdrop;
                  }
  
  
                  /*
                   * Okay, vps are legit. Check  access.  We'll require write access
                   * to both files.
                   */
                  if (vnode_authorize(src_vp, NULLVP,
                      (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), &context) != 0) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EBADF;
                          goto outdrop;
                  }
                  if (vnode_authorize(dst_vp, NULLVP,
                      (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), &context) != 0) {
                          vnode_put(src_vp);
                          vnode_put(dst_vp);
                          fp_drop(p, fd2, fp2, 0);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  /* Pass it on through to the fs */
                  error = VNOP_IOCTL(src_vp, cmd, (caddr_t)dst_vp, 0, &context);
  
                  vnode_put(src_vp);
                  vnode_put(dst_vp);
                  fp_drop(p, fd2, fp2, 0);
                  break;
          }
  
          /*
           * SPI for making a file compressed.
           */
          case F_MAKECOMPRESSED: {
                  uint32_t gcounter = CAST_DOWN_EXPLICIT(uint32_t, uap->arg);
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode*)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  /* get the vnode */
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* Is it a file? */
                  if ((vnode_isreg(vp) == 0) && (vnode_islnk(vp) == 0)) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  /* invoke ioctl to pass off to FS */
                  /* Only go forward if you have write access */
                  vfs_context_t ctx = vfs_context_current();
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), ctx) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  error = VNOP_IOCTL(vp, cmd, (caddr_t)&gcounter, 0, &context);
  
                  vnode_put(vp);
                  break;
          }
  
          /*
           * SPI (private) for indicating to a filesystem that subsequent writes to
           * the open FD will written to the Fastflow.
           */
          case F_SET_GREEDY_MODE:
          /* intentionally drop through to the same handler as F_SETSTATIC.
           * both fcntls should pass the argument and their selector into VNOP_IOCTL.
           */
  
          /*
           * SPI (private) for indicating to a filesystem that subsequent writes to
           * the open FD will represent static content.
           */
          case F_SETSTATICCONTENT: {
                  caddr_t ioctl_arg = NULL;
  
                  if (uap->arg) {
                          ioctl_arg = (caddr_t) 1;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* Only go forward if you have write access */
                  vfs_context_t ctx = vfs_context_current();
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), ctx) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  error = VNOP_IOCTL(vp, cmd, ioctl_arg, 0, &context);
                  (void)vnode_put(vp);
  
                  break;
          }
  
          /*
           * SPI (private) for indicating to the lower level storage driver that the
           * subsequent writes should be of a particular IO type (burst, greedy, static),
           * or other flavors that may be necessary.
           */
          case F_SETIOTYPE: {
                  caddr_t param_ptr;
                  uint32_t param;
  
                  if (uap->arg) {
                          /* extract 32 bits of flags from userland */
                          param_ptr = (caddr_t) uap->arg;
                          param = (uint32_t) param_ptr;
                  } else {
                          /* If no argument is specified, error out */
                          error = EINVAL;
                          goto out;
                  }
  
                  /*
                   * Validate the different types of flags that can be specified:
                   * all of them are mutually exclusive for now.
                   */
                  switch (param) {
                  case F_IOTYPE_ISOCHRONOUS:
                          break;
  
                  default:
                          error = EINVAL;
                          goto out;
                  }
  
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  error = vnode_getwithref(vp);
                  if (error) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* Only go forward if you have write access */
                  vfs_context_t ctx = vfs_context_current();
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), ctx) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  error = VNOP_IOCTL(vp, cmd, param_ptr, 0, &context);
                  (void)vnode_put(vp);
  
                  break;
          }
  
          /*
           * Set the vnode pointed to by 'fd'
           * and tag it as the (potentially future) backing store
           * for another filesystem
           */
          case F_SETBACKINGSTORE: {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
  
                  if (vp->v_tag != VT_HFS) {
                          error = EINVAL;
                          goto out;
                  }
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* only proceed if you have write access */
                  vfs_context_t ctx = vfs_context_current();
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), ctx) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
  
                  /* If arg != 0, set, otherwise unset */
                  if (uap->arg) {
                          error = VNOP_IOCTL(vp, cmd, (caddr_t)1, 0, &context);
                  } else {
                          error = VNOP_IOCTL(vp, cmd, (caddr_t)NULL, 0, &context);
                  }
  
                  vnode_put(vp);
                  break;
          }
  
          /*
           * like F_GETPATH, but special semantics for
           * the mobile time machine handler.
           */
          case F_GETPATH_MTMINFO: {
                  char *pathbufp;
                  int pathlen;
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  pathlen = MAXPATHLEN;
                  pathbufp = zalloc(ZV_NAMEI);
  
                  if ((error = vnode_getwithref(vp)) == 0) {
                          int backingstore = 0;
  
                          /* Check for error from vn_getpath before moving on */
                          if ((error = vn_getpath(vp, pathbufp, &pathlen)) == 0) {
                                  if (vp->v_tag == VT_HFS) {
                                          error = VNOP_IOCTL(vp, cmd, (caddr_t) &backingstore, 0, &context);
                                  }
                                  (void)vnode_put(vp);
  
                                  if (error == 0) {
                                          error = copyout((caddr_t)pathbufp, argp, pathlen);
                                  }
                                  if (error == 0) {
                                          /*
                                           * If the copyout was successful, now check to ensure
                                           * that this vnode is not a BACKINGSTORE vnode.  mtmd
                                           * wants the path regardless.
                                           */
                                          if (backingstore) {
                                                  error = EBUSY;
                                          }
                                  }
                          } else {
                                  (void)vnode_put(vp);
                          }
                  }
  
                  zfree(ZV_NAMEI, pathbufp);
                  goto outdrop;
          }
  
          case F_RECYCLE: {
  #if !DEBUG && !DEVELOPMENT
                  bool allowed = false;
  
                  //
                  // non-debug and non-development kernels have restrictions
                  // on who can all this fcntl.  the process has to be marked
                  // with the dataless-manipulator entitlement and either the
                  // process or thread have to be marked rapid-aging.
                  //
                  if (!vfs_context_is_dataless_manipulator(&context)) {
                          error = EPERM;
                          goto out;
                  }
  
                  proc_t proc = vfs_context_proc(&context);
                  if (proc && (proc->p_lflag & P_LRAGE_VNODES)) {
                          allowed = true;
                  } else {
                          thread_t thr = vfs_context_thread(&context);
                          if (thr) {
                                  struct uthread *ut = get_bsdthread_info(thr);
  
                                  if (ut && (ut->uu_flag & UT_RAGE_VNODES)) {
                                          allowed = true;
                                  }
                          }
                  }
                  if (!allowed) {
                          error = EPERM;
                          goto out;
                  }
  #endif
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  vnode_recycle(vp);
                  break;
          }
  
  #if CONFIG_FILE_LEASES
          case F_SETLEASE: {
                  struct fileglob *fg;
                  int fl_type;
                  int expcounts;
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  fg = fp->fp_glob;;
                  proc_fdunlock(p);
  
                  /*
                   * In order to allow a process to avoid breaking
                   * its own leases, the expected open count needs
                   * to be provided to F_SETLEASE when placing write lease.
                   * Similarly, in order to allow a process to place a read lease
                   * after opening the file multiple times in RW mode, the expected
                   * write count needs to be provided to F_SETLEASE when placing a
                   * read lease.
                   *
                   * We use the upper 30 bits of the integer argument (way more than
                   * enough) as the expected open/write count.
                   *
                   * If the caller passed 0 for the expected open count,
                   * assume 1.
                   */
                  fl_type = CAST_DOWN_EXPLICIT(int, uap->arg);
                  expcounts = (unsigned int)fl_type >> 2;
                  fl_type &= 3;
  
                  if (fl_type == F_WRLCK && expcounts == 0) {
                          expcounts = 1;
                  }
  
                  AUDIT_ARG(value32, fl_type);
  
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
  
                  /*
                   * Only support for regular file/dir mounted on local-based filesystem.
                   */
                  if ((vnode_vtype(vp) != VREG && vnode_vtype(vp) != VDIR) ||
                      !(vfs_flags(vnode_mount(vp)) & MNT_LOCAL)) {
                          error = EBADF;
                          vnode_put(vp);
                          goto outdrop;
                  }
  
                  /* For directory, we only support read lease. */
                  if (vnode_vtype(vp) == VDIR && fl_type == F_WRLCK) {
                          error = ENOTSUP;
                          vnode_put(vp);
                          goto outdrop;
                  }
  
                  switch (fl_type) {
                  case F_RDLCK:
                  case F_WRLCK:
                  case F_UNLCK:
                          error = vnode_setlease(vp, fg, fl_type, expcounts,
                              vfs_context_current());
                          break;
                  default:
                          error = EINVAL;
                          break;
                  }
  
                  vnode_put(vp);
                  goto outdrop;
          }
  
          case F_GETLEASE: {
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = vnode_getwithref(vp))) {
                          goto outdrop;
                  }
  
                  if ((vnode_vtype(vp) != VREG && vnode_vtype(vp) != VDIR) ||
                      !(vfs_flags(vnode_mount(vp)) & MNT_LOCAL)) {
                          error = EBADF;
                          vnode_put(vp);
                          goto outdrop;
                  }
  
                  error = 0;
                  *retval = vnode_getlease(vp);
                  vnode_put(vp);
                  goto outdrop;
          }
  #endif /* CONFIG_FILE_LEASES */
  
          /* SPI (private) for asserting background access to a file */
          case F_ASSERT_BG_ACCESS:
          /* SPI (private) for releasing background access to a file */
          case F_RELEASE_BG_ACCESS: {
                  /*
                   * Check if the process is platform code, which means
                   * that it is considered part of the Operating System.
                   */
                  if (!csproc_get_platform_binary(p)) {
                          error = EPERM;
                          goto out;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
  
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if (vnode_getwithref(vp)) {
                          error = ENOENT;
                          goto outdrop;
                  }
  
                  /* Verify that vp points to a file and not a directory */
                  if (!vnode_isreg(vp)) {
                          vnode_put(vp);
                          error = EINVAL;
                          goto outdrop;
                  }
  
                  /* Only proceed if you have write access */
                  if (vnode_authorize(vp, NULLVP, (KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA), &context) != 0) {
                          vnode_put(vp);
                          error = EBADF;
                          goto outdrop;
                  }
  
                  if (cmd == F_ASSERT_BG_ACCESS) {
                          fassertbgaccess_t args;
  
                          if ((error = copyin(argp, (caddr_t)&args, sizeof(args)))) {
                                  vnode_put(vp);
                                  goto outdrop;
                          }
  
                          error = VNOP_IOCTL(vp, F_ASSERT_BG_ACCESS, (caddr_t)&args, 0, &context);
                  } else {
                          // cmd == F_RELEASE_BG_ACCESS
                          error = VNOP_IOCTL(vp, F_RELEASE_BG_ACCESS, (caddr_t)NULL, 0, &context);
                  }
  
                  vnode_put(vp);
  
                  goto outdrop;
          }
  
          default:
                  /*
                   * This is an fcntl() that we d not recognize at this level;
                   * if this is a vnode, we send it down into the VNOP_IOCTL
                   * for this vnode; this can include special devices, and will
                   * effectively overload fcntl() to send ioctl()'s.
                   */
                  if ((cmd & IOC_VOID) && (cmd & IOC_INOUT)) {
                          error = EINVAL;
                          goto out;
                  }
  
                  /* Catch any now-invalid fcntl() selectors */
                  switch (cmd) {
                  case (int)APFSIOC_REVERT_TO_SNAPSHOT:
                  case (int)FSIOC_FIOSEEKHOLE:
                  case (int)FSIOC_FIOSEEKDATA:
                  case (int)FSIOC_CAS_BSDFLAGS:
                  case (int)FSIOC_AUTH_FS:
                  case HFS_GET_BOOT_INFO:
                  case HFS_SET_BOOT_INFO:
                  case FIOPINSWAP:
                  case F_MARKDEPENDENCY:
                  case TIOCREVOKE:
                  case TIOCREVOKECLEAR:
                          error = EINVAL;
                          goto out;
                  default:
                          break;
                  }
  
                  if (fp->f_type != DTYPE_VNODE) {
                          error = EBADF;
                          goto out;
                  }
                  vp = (struct vnode *)fp_get_data(fp);
                  proc_fdunlock(p);
  
                  if ((error = vnode_getwithref(vp)) == 0) {
  #define STK_PARAMS 128
                          char stkbuf[STK_PARAMS] = {0};
                          unsigned int size;
                          caddr_t data, memp;
                          /*
                           * For this to work properly, we have to copy in the
                           * ioctl() cmd argument if there is one; we must also
                           * check that a command parameter, if present, does
                           * not exceed the maximum command length dictated by
                           * the number of bits we have available in the command
                           * to represent a structure length.  Finally, we have
                           * to copy the results back out, if it is that type of
                           * ioctl().
                           */
                          size = IOCPARM_LEN(cmd);
                          if (size > IOCPARM_MAX) {
                                  (void)vnode_put(vp);
                                  error = EINVAL;
                                  break;
                          }
  
                          memp = NULL;
                          if (size > sizeof(stkbuf)) {
                                  memp = (caddr_t)kalloc_data(size, Z_WAITOK);
                                  if (memp == 0) {
                                          (void)vnode_put(vp);
                                          error = ENOMEM;
                                          goto outdrop;
                                  }
                                  data = memp;
                          } else {
                                  data = &stkbuf[0];
                          }
  
                          if (cmd & IOC_IN) {
                                  if (size) {
                                          /* structure */
                                          error = copyin(argp, data, size);
                                          if (error) {
                                                  (void)vnode_put(vp);
                                                  if (memp) {
                                                          kfree_data(memp, size);
                                                  }
                                                  goto outdrop;
                                          }
  
                                          /* Bzero the section beyond that which was needed */
                                          if (size <= sizeof(stkbuf)) {
                                                  bzero((((uint8_t*)data) + size), (sizeof(stkbuf) - size));
                                          }
                                  } else {
                                          /* int */
                                          if (is64bit) {
                                                  *(user_addr_t *)data = argp;
                                          } else {
                                                  *(uint32_t *)data = (uint32_t)argp;
                                          }
                                  };
                          } else if ((cmd & IOC_OUT) && size) {
                                  /*
                                   * Zero the buffer so the user always
                                   * gets back something deterministic.
                                   */
                                  bzero(data, size);
                          } else if (cmd & IOC_VOID) {
                                  if (is64bit) {
                                          *(user_addr_t *)data = argp;
                                  } else {
                                          *(uint32_t *)data = (uint32_t)argp;
                                  }
                          }
  
                          error = VNOP_IOCTL(vp, cmd, CAST_DOWN(caddr_t, data), 0, &context);
  
                          (void)vnode_put(vp);
  
                          /* Copy any output data to user */
                          if (error == 0 && (cmd & IOC_OUT) && size) {
                                  error = copyout(data, argp, size);
                          }
                          if (memp) {
                                  kfree_data(memp, size);
                          }
                  }
                  break;
          }
  
  outdrop:
          return sys_fcntl_outdrop(p, fd, fp, vp, error);
  
  out:
          return sys_fcntl_out(p, fd, fp, error);
  }
  
  
  /*
   * sys_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
   *      fp_guard_exception:???          Guarded file descriptor
   *      close_internal:EBADF
   *      close_internal:???              Anything returnable by a per-fileops
   *                                      close function
   */
  int
  sys_close(proc_t p, struct close_args *uap, __unused int32_t *retval)
  {
          __pthread_testcancel(1);
          return close_nocancel(p, uap->fd);
  }
  
  int
  sys_close_nocancel(proc_t p, struct close_nocancel_args *uap, __unused int32_t *retval)
  {
          return close_nocancel(p, uap->fd);
  }
  
  int
  close_nocancel(proc_t p, int fd)
  {
          struct fileproc *fp;
  
          AUDIT_SYSCLOSE(p, fd);
  
          proc_fdlock(p);
          if ((fp = fp_get_noref_locked(p, fd)) == NULL) {
                  proc_fdunlock(p);
                  return EBADF;
          }
  
          if (fp_isguarded(fp, GUARD_CLOSE)) {
                  int error = fp_guard_exception(p, fd, fp, kGUARD_EXC_CLOSE);
                  proc_fdunlock(p);
                  return error;
          }
  
          return fp_close_and_unlock(p, fd, fp, 0);
  }
  
  
  /*
   * fstat
   *
   * 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
  fstat(proc_t p, int fd, user_addr_t ub, user_addr_t xsecurity,
      user_addr_t xsecurity_size, int isstat64)
  {
          struct fileproc *fp;
          union {
                  struct stat sb;
                  struct stat64 sb64;
          } source;
          union {
                  struct user64_stat user64_sb;
                  struct user32_stat user32_sb;
                  struct user64_stat64 user64_sb64;
                  struct user32_stat64 user32_sb64;
          } dest;
          int error, my_size;
          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 = (caddr_t)fp_get_data(fp);
          fsec = KAUTH_FILESEC_NONE;
  
          sbptr = (void *)&source;
  
          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, 0, ctx,
                                      fp->fp_glob->fg_cred);
                          } else {
                                  error = vn_stat((vnode_t)data, sbptr, &fsec, isstat64, 0, 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:
                  error = kqueue_stat((void *)data, sbptr, isstat64, p);
                  break;
  
          default:
                  error = EBADF;
                  goto out;
          }
          if (error == 0) {
                  caddr_t sbp;
  
                  if (isstat64 != 0) {
                          source.sb64.st_lspare = 0;
                          source.sb64.st_qspare[0] = 0LL;
                          source.sb64.st_qspare[1] = 0LL;
  
                          if (IS_64BIT_PROCESS(p)) {
                                  munge_user64_stat64(&source.sb64, &dest.user64_sb64);
                                  my_size = sizeof(dest.user64_sb64);
                                  sbp = (caddr_t)&dest.user64_sb64;
                          } else {
                                  munge_user32_stat64(&source.sb64, &dest.user32_sb64);
                                  my_size = sizeof(dest.user32_sb64);
                                  sbp = (caddr_t)&dest.user32_sb64;
                          }
                  } else {
                          source.sb.st_lspare = 0;
                          source.sb.st_qspare[0] = 0LL;
                          source.sb.st_qspare[1] = 0LL;
                          if (IS_64BIT_PROCESS(p)) {
                                  munge_user64_stat(&source.sb, &dest.user64_sb);
                                  my_size = sizeof(dest.user64_sb);
                                  sbp = (caddr_t)&dest.user64_sb;
                          } else {
                                  munge_user32_stat(&source.sb, &dest.user32_sb);
                                  my_size = sizeof(dest.user32_sb);
                                  sbp = (caddr_t)&dest.user32_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;
  }
  
  
  /*
   * sys_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 fstat)
   */
  int
  sys_fstat_extended(proc_t p, struct fstat_extended_args *uap, __unused int32_t *retval)
  {
          return fstat(p, uap->fd, uap->ub, uap->xsecurity, uap->xsecurity_size, 0);
  }
  
  
  /*
   * sys_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 fstat)
   */
  int
  sys_fstat(proc_t p, struct fstat_args *uap, __unused int32_t *retval)
  {
          return fstat(p, uap->fd, uap->ub, 0, 0, 0);
  }
  
  
  /*
   * sys_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 fstat)
   */
  int
  sys_fstat64_extended(proc_t p, struct fstat64_extended_args *uap, __unused int32_t *retval)
  {
          return fstat(p, uap->fd, uap->ub, uap->xsecurity, uap->xsecurity_size, 1);
  }
  
  
  /*
   * sys_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 fstat)
   */
  int
  sys_fstat64(proc_t p, struct fstat64_args *uap, __unused int32_t *retval)
  {
          return fstat(p, uap->fd, uap->ub, 0, 0, 1);
  }
  
  
  /*
   * sys_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
  sys_fpathconf(proc_t p, struct fpathconf_args *uap, int32_t *retval)
  {
          int fd = uap->fd;
          struct fileproc *fp;
          struct vnode *vp;
          int error = 0;
          file_type_t type;
  
  
          AUDIT_ARG(fd, uap->fd);
          if ((error = fp_lookup(p, fd, &fp, 0))) {
                  return error;
          }
          type = fp->f_type;
  
          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:
                  if (uap->name != _PC_PIPE_BUF) {
                          error = EINVAL;
                          goto out;
                  }
                  *retval = PIPE_BUF;
                  error = 0;
                  goto out;
  
          case DTYPE_VNODE:
                  vp = (struct vnode *)fp_get_data(fp);
  
                  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;
  
          default:
                  error = EINVAL;
                  goto out;
          }
          /*NOTREACHED*/
  out:
          fp_drop(p, fd, fp, 0);
          return error;
  }
  
  /*
   * sys_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
  sys_flock(proc_t p, struct flock_args *uap, __unused int32_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;
                  error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob, F_UNLCK, &lf, F_FLOCK, ctx, NULL);
                  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(kauth_cred_get(), fp->fp_glob, F_SETLK, &lf);
          if (error) {
                  goto out;
          }
  #endif
          error = VNOP_ADVLOCK(vp, (caddr_t)fp->fp_glob, F_SETLK, &lf,
              (how & LOCK_NB ? F_FLOCK : F_FLOCK | F_WAIT),
              ctx, NULL);
          if (!error) {
                  os_atomic_or(&fp->fp_glob->fg_flag, FWASLOCKED, relaxed);
          }
  out:
          (void)vnode_put(vp);
  out1:
          fp_drop(p, fd, fp, 0);
          return error;
  }
  
  /*
   * sys_fileport_makeport
   *
   * Description: Obtain a Mach send right for a given file descriptor.
   *
   * Parameters:  p               Process calling fileport
   *              uap->fd         The fd to reference
   *              uap->portnamep  User address at which to place port name.
   *
   * Returns:     0               Success.
   *              EBADF           Bad file descriptor.
   *              EINVAL          File descriptor had type that cannot be sent, misc. other errors.
   *              EFAULT          Address at which to store port name is not valid.
   *              EAGAIN          Resource shortage.
   *
   * Implicit returns:
   *              On success, name of send right is stored at user-specified address.
   */
  int
  sys_fileport_makeport(proc_t p, struct fileport_makeport_args *uap,
      __unused int *retval)
  {
          int err;
          int fd = uap->fd;
          user_addr_t user_portaddr = uap->portnamep;
          struct fileproc *fp = FILEPROC_NULL;
          struct fileglob *fg = NULL;
          ipc_port_t fileport;
          mach_port_name_t name = MACH_PORT_NULL;
  
          proc_fdlock(p);
          err = fp_lookup(p, fd, &fp, 1);
          if (err != 0) {
                  goto out_unlock;
          }
  
          fg = fp->fp_glob;
          if (!fg_sendable(fg)) {
                  err = EINVAL;
                  goto out_unlock;
          }
  
          if (fp_isguarded(fp, GUARD_FILEPORT)) {
                  err = fp_guard_exception(p, fd, fp, kGUARD_EXC_FILEPORT);
                  goto out_unlock;
          }
  
          /* Dropped when port is deallocated */
          fg_ref(p, fg);
  
          proc_fdunlock(p);
  
          /* Allocate and initialize a port */
          fileport = fileport_alloc(fg);
          if (fileport == IPC_PORT_NULL) {
                  fg_drop_live(fg);
                  err = EAGAIN;
                  goto out;
          }
  
          /* Add an entry.  Deallocates port on failure. */
          name = ipc_port_copyout_send(fileport, get_task_ipcspace(proc_task(p)));
          if (!MACH_PORT_VALID(name)) {
                  err = EINVAL;
                  goto out;
          }
  
          err = copyout(&name, user_portaddr, sizeof(mach_port_name_t));
          if (err != 0) {
                  goto out;
          }
  
          /* Tag the fileglob for debugging purposes */
          lck_mtx_lock_spin(&fg->fg_lock);
          fg->fg_lflags |= FG_PORTMADE;
          lck_mtx_unlock(&fg->fg_lock);
  
          fp_drop(p, fd, fp, 0);
  
          return 0;
  
  out_unlock:
          proc_fdunlock(p);
  out:
          if (MACH_PORT_VALID(name)) {
                  /* Don't care if another thread races us to deallocate the entry */
                  (void) mach_port_deallocate(get_task_ipcspace(proc_task(p)), name);
          }
  
          if (fp != FILEPROC_NULL) {
                  fp_drop(p, fd, fp, 0);
          }
  
          return err;
  }
  
  void
  fileport_releasefg(struct fileglob *fg)
  {
          (void)fg_drop(PROC_NULL, fg);
  }
  
  /*
   * fileport_makefd
   *
   * Description: Obtain the file descriptor for a given Mach send right.
   *
   * Returns:     0               Success
   *              EINVAL          Invalid Mach port name, or port is not for a file.
   *      fdalloc:EMFILE
   *      fdalloc:ENOMEM          Unable to allocate fileproc or extend file table.
   *
   * Implicit returns:
   *              *retval (modified)              The new descriptor
   */
  int
  fileport_makefd(proc_t p, ipc_port_t port, fileproc_flags_t fp_flags, int *retval)
  {
          struct fileglob *fg;
          struct fileproc *fp = FILEPROC_NULL;
          int fd;
          int err;
  
          fg = fileport_port_to_fileglob(port);
          if (fg == NULL) {
                  err = EINVAL;
                  goto out;
          }
  
          fp = fileproc_alloc_init();
  
          proc_fdlock(p);
          err = fdalloc(p, 0, &fd);
          if (err != 0) {
                  proc_fdunlock(p);
                  goto out;
          }
          if (fp_flags) {
                  fp->fp_flags |= fp_flags;
          }
  
          fp->fp_glob = fg;
          fg_ref(p, fg);
  
          procfdtbl_releasefd(p, fd, fp);
          proc_fdunlock(p);
  
          *retval = fd;
          err = 0;
  out:
          if ((fp != NULL) && (0 != err)) {
                  fileproc_free(fp);
          }
  
          return err;
  }
  
  /*
   * sys_fileport_makefd
   *
   * Description: Obtain the file descriptor for a given Mach send right.
   *
   * Parameters:  p               Process calling fileport
   *              uap->port       Name of send right to file port.
   *
   * Returns:     0               Success
   *              EINVAL          Invalid Mach port name, or port is not for a file.
   *      fdalloc:EMFILE
   *      fdalloc:ENOMEM          Unable to allocate fileproc or extend file table.
   *
   * Implicit returns:
   *              *retval (modified)              The new descriptor
   */
  int
  sys_fileport_makefd(proc_t p, struct fileport_makefd_args *uap, int32_t *retval)
  {
          ipc_port_t port = IPC_PORT_NULL;
          mach_port_name_t send = uap->port;
          kern_return_t res;
          int err;
  
          res = ipc_object_copyin(get_task_ipcspace(proc_task(p)),
              send, MACH_MSG_TYPE_COPY_SEND, &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
  
          if (res == KERN_SUCCESS) {
                  err = fileport_makefd(p, port, FP_CLOEXEC, retval);
          } else {
                  err = EINVAL;
          }
  
          if (IPC_PORT_NULL != port) {
                  ipc_port_release_send(port);
          }
  
          return err;
  }
  
  
  #pragma mark fileops wrappers
  
  /*
   * 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);
  }
  
  int
  fo_no_read(struct fileproc *fp, struct uio *uio, int flags, vfs_context_t ctx)
  {
  #pragma unused(fp, uio, flags, ctx)
          return ENXIO;
  }
  
  
  /*
   * 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);
  }
  
  int
  fo_no_write(struct fileproc *fp, struct uio *uio, int flags, vfs_context_t ctx)
  {
  #pragma unused(fp, uio, flags, ctx)
          return ENXIO;
  }
  
  
  /*
   * 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;
  }
  
  int
  fo_no_ioctl(struct fileproc *fp, u_long com, caddr_t data, vfs_context_t ctx)
  {
  #pragma unused(fp, com, data, ctx)
          return ENOTTY;
  }
  
  
  /*
   * 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);
  }
  
  int
  fo_no_select(struct fileproc *fp, int which, void *wql, vfs_context_t ctx)
  {
  #pragma unused(fp, which, wql, ctx)
          return ENOTSUP;
  }
  
  
  /*
   * 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_drain
   *
   * Description: Generic fileops kqueue filter indirected through the fileops
   *              pointer in the fileproc structure
   *
   * Parameters:  fp                              fileproc structure pointer
   *              ctx                             VFS context for operation
   *
   * Returns:     0                               Success
   *              !0                              errno from drain
   */
  int
  fo_drain(struct fileproc *fp, vfs_context_t ctx)
  {
          return (*fp->f_ops->fo_drain)(fp, ctx);
  }
  
  int
  fo_no_drain(struct fileproc *fp, vfs_context_t ctx)
  {
  #pragma unused(fp, ctx)
          return ENOTSUP;
  }
  
  
  /*
   * 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
   *
   * Returns:     (kn->kn_flags & EV_ERROR)       error in kn->kn_data
   *              0                               Filter is not active
   *              !0                              Filter is active
   */
  int
  fo_kqfilter(struct fileproc *fp, struct knote *kn, struct kevent_qos_s *kev)
  {
          return (*fp->f_ops->fo_kqfilter)(fp, kn, kev);
  }
  
  int
  fo_no_kqfilter(struct fileproc *fp, struct knote *kn, struct kevent_qos_s *kev)
  {
  #pragma unused(fp, kev)
          knote_set_error(kn, ENOTSUP);
          return 0;
  }