/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * 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.
 *
 *      @(#)fdesc_vnops.c       8.17 (Berkeley) 5/22/95
 *
 */

/*
 * /dev/fd Filesystem
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/proc_internal.h>
#include <sys/kernel.h> /* boottime */
#include <sys/resourcevar.h>
#include <sys/filedesc.h>
#include <sys/kauth.h>
#include <sys/vnode_internal.h>
#include <sys/malloc.h>
#include <sys/file_internal.h>
#include <sys/stat.h>
#include <sys/mount_internal.h>
#include <sys/namei.h>
#include <sys/dirent.h>
#include <sys/ubc.h>
#include <sys/socketvar.h>
#include <sys/pipe.h>
#include <sys/uio_internal.h>
#include <miscfs/fdesc/fdesc.h>
#include <vfs/vfs_support.h>
#include <pexpert/pexpert.h>

#define FDL_WANT        0x01
#define FDL_LOCKED      0x02
static int fdcache_lock;


#if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
#endif

#define NFDCACHE 3

#define FD_NHASH(ix) \
        (&fdhashtbl[(ix) & fdhash])
LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
u_long fdhash;

static int fdesc_attr(int fd, struct vnode_attr *vap, vfs_context_t a_context);


/*
 * Initialise cache headers
 */
int
fdesc_init(__unused struct vfsconf *vfsp)
{

        fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash);

        return( 0 );
}

int
fdesc_allocvp(ftype, ix, mp, vpp, vtype)
        fdntype ftype;
        int ix;
        struct mount *mp;
        struct vnode **vpp;
        enum vtype vtype;
{
        struct fdhashhead *fc;
        struct fdescnode *fd;
        int error = 0;
        int vid = 0;
        struct vnode_fsparam vfsp;

        fc = FD_NHASH(ix);
loop:
        for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
                if (fd->fd_ix == ix && vnode_mount(fd->fd_vnode) == mp) {
                        /*
                         * doing a vnode_getwithvid isn't technically 
                         * necessary since fdesc is an unsafe filesystem
                         * and we're running behind a funnel at this point
                         * however, vnode_get always succeeds, which isn't
                         * what we want if this vnode is in the process of
                         * being terminated
                         */
                        vid = vnode_vid(fd->fd_vnode);

                        if (vnode_getwithvid(fd->fd_vnode, vid))
                                goto loop;
                        *vpp = fd->fd_vnode;
                        (*vpp)->v_type = vtype;

                        return (error);
                }
        }

        /*
         * otherwise lock the array while we call getnewvnode
         * since that can block.
         */ 
        if (fdcache_lock & FDL_LOCKED) {
                fdcache_lock |= FDL_WANT;
                sleep((caddr_t) &fdcache_lock, PINOD);
                goto loop;
        }
        fdcache_lock |= FDL_LOCKED;

        MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);

        vfsp.vnfs_mp = mp;
        vfsp.vnfs_vtype = vtype;
        vfsp.vnfs_str = "fdesc";
        vfsp.vnfs_dvp = 0;
        vfsp.vnfs_fsnode = fd;
        vfsp.vnfs_cnp = 0;
        vfsp.vnfs_vops = fdesc_vnodeop_p;
        vfsp.vnfs_rdev = 0;
        vfsp.vnfs_filesize = 0;
        vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE;
        vfsp.vnfs_marksystem = 0;
        if (ftype == Froot)
                vfsp.vnfs_markroot = 1;
        else
                vfsp.vnfs_markroot = 0;

        error = vnode_create(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, vpp);
        if (error) {
                FREE(fd, M_TEMP);
                goto out;
        }
        (*vpp)->v_tag = VT_FDESC;
        fd->fd_vnode = *vpp;
        fd->fd_type = ftype;
        fd->fd_fd = -1;
        fd->fd_link = 0;
        fd->fd_ix = ix;
        LIST_INSERT_HEAD(fc, fd, fd_hash);

out:
        fdcache_lock &= ~FDL_LOCKED;

        if (fdcache_lock & FDL_WANT) {
                fdcache_lock &= ~FDL_WANT;
                wakeup((caddr_t) &fdcache_lock);
        }

        return (error);
}

/*
 * vp is the current namei directory
 * ndp is the name to locate in that directory...
 */
int
fdesc_lookup(ap)
        struct vnop_lookup_args /* {
                struct vnode * a_dvp;
                struct vnode ** a_vpp;
                struct componentname * a_cnp;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode **vpp = ap->a_vpp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        char *pname = cnp->cn_nameptr;
        struct proc *p = vfs_context_proc(ap->a_context);
        int numfiles = p->p_fd->fd_nfiles;
        int fd;
        int error;
        struct vnode *fvp;
        char *ln;

        if (cnp->cn_namelen == 1 && *pname == '.') {
                *vpp = dvp;
                
                if ( (error = vnode_get(dvp)) ) {
                        return(error);
                }
                return (0);
        }

        switch (VTOFDESC(dvp)->fd_type) {
        default:
        case Flink:
        case Fdesc:
                /* should never happen */
                error = ENOTDIR;
                goto bad;

        case Froot:
                if (cnp->cn_namelen == 2 && bcmp(pname, "fd", 2) == 0) {
                        error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp, VDIR);
                        if (error)
                                goto bad;
                        *vpp = fvp;
                        return (0);
                }

                ln = NULL;
                switch (cnp->cn_namelen) {
                case 5:
                        if (bcmp(pname, "stdin", 5) == 0) {
                                ln = "fd/0";
                                fd = FD_STDIN;
                        }
                        break;
                case 6:
                        if (bcmp(pname, "stdout", 6) == 0) {
                                ln = "fd/1";
                                fd = FD_STDOUT;
                        } else
                        if (bcmp(pname, "stderr", 6) == 0) {
                                ln = "fd/2";
                                fd = FD_STDERR;
                        }
                        break;
                }

                if (ln) {
                        error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp, VLNK);
                        if (error)
                                goto bad;
                        VTOFDESC(fvp)->fd_link = ln;
                        *vpp = fvp;
                        return (0);
                } else {
                        error = ENOENT;
                        goto bad;
                }

                /* FALL THROUGH */

        case Fdevfd:
                if (cnp->cn_namelen == 2 && bcmp(pname, "..", 2) == 0) {
                        if ((error = fdesc_root(dvp->v_mount, vpp, ap->a_context)))
                                goto bad;
                        return (0);
                }

                fd = 0;
                while (*pname >= '0' && *pname <= '9') {
                        fd = 10 * fd + *pname++ - '0';
                        if (fd >= numfiles)
                                break;
                }

                if (*pname != '\0') {
                        error = ENOENT;
                        goto bad;
                }

                if (fd < 0 || fd >= numfiles ||
                                *fdfile(p, fd) == NULL ||
                                (*fdflags(p, fd) & UF_RESERVED)) {
                        error = EBADF;
                        goto bad;
                }

                error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp, VNON);
                if (error)
                        goto bad;
                VTOFDESC(fvp)->fd_fd = fd;
                *vpp = fvp;
                return (0);
        }

bad:;
        *vpp = NULL;
        return (error);
}

int
fdesc_open(ap)
        struct vnop_open_args /* {
                struct vnode *a_vp;
                int  a_mode;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct proc *p = vfs_context_proc(ap->a_context);
        int error = 0;

        switch (VTOFDESC(vp)->fd_type) {
        case Fdesc:
                /*
                 * XXX Kludge: set p->p_dupfd to contain the value of the
                 * the file descriptor being sought for duplication. The error 
                 * return ensures that the vnode for this device will be
                 * released by vn_open. Open will detect this special error and
                 * take the actions in dupfdopen.  Other callers of vn_open or
                 * vnop_open will simply report the error.
                 */
                p->p_dupfd = VTOFDESC(vp)->fd_fd;       /* XXX */
                error = ENODEV;
                break;

        }

        return (error);
}

static int
fdesc_attr(int fd, struct vnode_attr *vap, vfs_context_t a_context)
{
        struct fileproc *fp;
        struct proc *p = vfs_context_proc(a_context);
        struct stat stb;
        int error;

        if ((error = fp_lookup(p, fd, &fp, 0)))
                return (error);
        switch (fp->f_fglob->fg_type) {
        case DTYPE_VNODE:
                if(error = vnode_getwithref((struct vnode *) fp->f_fglob->fg_data)) {
                        break;
                }
                if ((error = vnode_authorize((struct vnode *)fp->f_fglob->fg_data,
                         NULL,
                         KAUTH_VNODE_READ_ATTRIBUTES | KAUTH_VNODE_READ_SECURITY,
                         a_context)) == 0)
                        error = vnode_getattr((struct vnode *)fp->f_fglob->fg_data, vap, a_context);
                if (error == 0 && vap->va_type == VDIR) {
                        /*
                         * directories can cause loops in the namespace,
                         * so turn off the 'x' bits to avoid trouble.
                         *
                         * XXX ACLs break this, of course
                         */
                        vap->va_mode &= ~((VEXEC)|(VEXEC>>3)|(VEXEC>>6));
                }
                (void)vnode_put((struct vnode *) fp->f_fglob->fg_data);
                break;

        case DTYPE_SOCKET:
        case DTYPE_PIPE:
                if (fp->f_fglob->fg_type == DTYPE_SOCKET)
                        error = soo_stat((struct socket *)fp->f_fglob->fg_data, &stb);
                else
                        error = pipe_stat((struct socket *)fp->f_fglob->fg_data, &stb);

                if (error == 0) {
                        if (fp->f_fglob->fg_type == DTYPE_SOCKET)
                                VATTR_RETURN(vap, va_type, VSOCK);
                        else
                                VATTR_RETURN(vap, va_type, VFIFO);

                        VATTR_RETURN(vap, va_mode, stb.st_mode);
                        VATTR_RETURN(vap, va_nlink, stb.st_nlink);
                        VATTR_RETURN(vap, va_uid, stb.st_uid);
                        VATTR_RETURN(vap, va_gid, stb.st_gid);
                        VATTR_RETURN(vap, va_fsid, stb.st_dev);
                        VATTR_RETURN(vap, va_fileid, stb.st_ino);
                        VATTR_RETURN(vap, va_data_size, stb.st_size);
                        VATTR_RETURN(vap, va_access_time, stb.st_atimespec);
                        VATTR_RETURN(vap, va_modify_time, stb.st_mtimespec);
                        VATTR_RETURN(vap, va_change_time, stb.st_ctimespec);
                        VATTR_RETURN(vap, va_gen, stb.st_gen);
                        VATTR_RETURN(vap, va_flags, stb.st_flags);
                        VATTR_RETURN(vap, va_rdev, stb.st_rdev);
                        VATTR_RETURN(vap, va_total_alloc, stb.st_blocks * stb.st_blksize);
                        VATTR_RETURN(vap, va_acl, NULL);
                }
                break;

        default:
                error = EBADF;
        }

        fp_drop(p, fd, fp, 0);
        return (error);
}

int
fdesc_getattr(ap)
        struct vnop_getattr_args /* {
                struct vnode *a_vp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct vnode_attr *vap = ap->a_vap;
        unsigned fd;
        int error = 0;
        struct timespec ts;

        switch (VTOFDESC(vp)->fd_type) {
        case Froot:
        case Fdevfd:
        case Flink:
                VATTR_RETURN(vap, va_fileid, VTOFDESC(vp)->fd_ix);
                VATTR_RETURN(vap, va_uid, 0);
                VATTR_RETURN(vap, va_gid, 0);
                VATTR_RETURN(vap, va_fsid, vp->v_mount->mnt_vfsstat.f_fsid.val[0]);
                VATTR_RETURN(vap, va_iosize, DEV_BSIZE);
                ts.tv_sec = boottime_sec();
                ts.tv_nsec = 0;
                VATTR_RETURN(vap, va_access_time, ts);
                VATTR_RETURN(vap, va_modify_time, ts);
                VATTR_RETURN(vap, va_change_time, ts);
                VATTR_RETURN(vap, va_gen, 0);
                VATTR_RETURN(vap, va_flags, 0);
                VATTR_RETURN(vap, va_rdev, 0);
                VATTR_RETURN(vap, va_acl, NULL);

                switch (VTOFDESC(vp)->fd_type) {
                case Flink:
                        VATTR_RETURN(vap, va_mode, S_IRUSR|S_IRGRP|S_IROTH);
                        VATTR_RETURN(vap, va_type, VLNK);       /* not strictly required */
                        VATTR_RETURN(vap, va_nlink, 1);
                        VATTR_RETURN(vap, va_data_size, strlen(VTOFDESC(vp)->fd_link));
                        break;

                default:
                        VATTR_RETURN(vap, va_mode, S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
                        VATTR_RETURN(vap, va_type, VDIR);
                        VATTR_RETURN(vap, va_nlink, 2);
                        VATTR_RETURN(vap, va_data_size, DEV_BSIZE);
                        break;
                }
                break;

        case Fdesc:
                fd = VTOFDESC(vp)->fd_fd;
                error = fdesc_attr(fd, vap, ap->a_context);
                break;

        default:
                return (EBADF);
                break;  
        }
        
        if (error == 0) {
                vp->v_type = vap->va_type;
        }

        return (error);
}

int
fdesc_setattr(ap)
        struct vnop_setattr_args /* {
                struct vnode *a_vp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        struct fileproc *fp;
        unsigned fd;
        int error;
        struct proc * p = vfs_context_proc(ap->a_context);

        /*
         * Can't mess with the root vnode
         */
        switch (VTOFDESC(ap->a_vp)->fd_type) {
        case Fdesc:
                break;

        default:
                return (EACCES);
        }

        fd = VTOFDESC(ap->a_vp)->fd_fd;
        if ((error = fp_lookup(vfs_context_proc(ap->a_context), fd, &fp, 0)))
                return (error);

        /*
         * Can setattr the underlying vnode, but not sockets!
         */
        switch (fp->f_fglob->fg_type) {
        case DTYPE_VNODE:
        {
                if ((error = vnode_getwithref((struct vnode *) fp->f_fglob->fg_data)) != 0)
                        break;
                error = vnode_setattr((struct vnode *) fp->f_fglob->fg_data, ap->a_vap, ap->a_context);
                (void)vnode_put((struct vnode *) fp->f_fglob->fg_data);
                break;
        }

        case DTYPE_SOCKET:
        case DTYPE_PIPE:
                error = 0;
                break;

        default:
                kprintf("fp->f_fglob->fg_type = %d\n", fp->f_fglob->fg_type);
        error = EBADF;
                break;
        }

        fp_drop(p, fd, fp, 0);
        return (error);
}

#define UIO_MX 16

static struct dirtmp {
        u_long d_fileno;
        u_short d_reclen;
        u_short d_namlen;
        char d_name[8];
} rootent[] = {
        { FD_DEVFD, UIO_MX, 2, "fd" },
        { FD_STDIN, UIO_MX, 5, "stdin" },
        { FD_STDOUT, UIO_MX, 6, "stdout" },
        { FD_STDERR, UIO_MX, 6, "stderr" },
        { 0, 0, 0, "" }
};

int
fdesc_readdir(ap)
        struct vnop_readdir_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int a_flags;
                int *a_eofflag;
                int *a_numdirent;
                vfs_context_t a_context;
        } */ *ap;
{
        struct uio *uio = ap->a_uio;
        struct proc *p = current_proc();
        int i, error;

        /*
         * We don't allow exporting fdesc mounts, and currently local
         * requests do not need cookies.
         */
        if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF))
                return (EINVAL);

        switch (VTOFDESC(ap->a_vp)->fd_type) {
        case Fdesc:
                return (ENOTDIR);

        default:
                break;
        }

        if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
                struct dirent d;
                struct dirent *dp = &d;
                struct dirtmp *dt;
                int fd;

                i = uio->uio_offset / UIO_MX;
                error = 0;

                while (uio_resid(uio) > 0) {
                        dt = &rootent[i];
                        if (dt->d_fileno == 0) {
                                /**eofflagp = 1;*/
                                break;
                        }
                        i++;
                        
                        switch (dt->d_fileno) {
                        case FD_STDIN:
                        case FD_STDOUT:
                        case FD_STDERR:
                                fd = dt->d_fileno - FD_STDIN;
                                if (fd >= p->p_fd->fd_nfiles)
                                        continue;
                                if (*fdfile(p, fd) == NULL &&
                                                !(*fdflags(p, fd) &
                                                        UF_RESERVED))
                                        continue;
                                break;
                        }
                        bzero((caddr_t) dp, UIO_MX);
                        dp->d_fileno = dt->d_fileno;
                        dp->d_namlen = dt->d_namlen;
                        dp->d_type = DT_UNKNOWN;
                        dp->d_reclen = dt->d_reclen;
                        bcopy(dt->d_name, dp->d_name, dp->d_namlen+1);
                        error = uiomove((caddr_t) dp, UIO_MX, uio);
                        if (error)
                                break;
                }
                uio->uio_offset = i * UIO_MX;
                return (error);
        }

        i = uio->uio_offset / UIO_MX;
        error = 0;
        while (uio_resid(uio) > 0) {
                if (i >= p->p_fd->fd_nfiles)
                        break;

                if (*fdfile(p, i) != NULL && !(*fdflags(p, i) & UF_RESERVED)) {
                        struct dirent d;
                        struct dirent *dp = &d;

                        bzero((caddr_t) dp, UIO_MX);

                        dp->d_namlen = sprintf(dp->d_name, "%d", i);
                        dp->d_reclen = UIO_MX;
                        dp->d_type = DT_UNKNOWN;
                        dp->d_fileno = i + FD_STDIN;
                        /*
                         * And ship to userland
                         */
                        error = uiomove((caddr_t) dp, UIO_MX, uio);
                        if (error)
                                break;
                }
                i++;
        }

        uio->uio_offset = i * UIO_MX;
        return (error);
}

int
fdesc_readlink(ap)
        struct vnop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        int error;

        if (vp->v_type != VLNK)
                return (EPERM);

        if (VTOFDESC(vp)->fd_type == Flink) {
                char *ln = VTOFDESC(vp)->fd_link;
                error = uiomove(ln, strlen(ln), ap->a_uio);
        } else {
                error = ENOTSUP;
        }

        return (error);
}

int
fdesc_read(__unused struct vnop_read_args *ap)
{

        return (ENOTSUP);
}

int
fdesc_write(__unused struct vnop_write_args *ap)
{
        return (ENOTSUP);
}

int
fdesc_ioctl(__unused struct vnop_ioctl_args *ap)
{
        return (ENOTSUP);
}

int
fdesc_select(__unused struct vnop_select_args *ap)
{
        return (ENOTSUP);
}

int
fdesc_inactive(ap)
        struct vnop_inactive_args /* {
                struct vnode *a_vp;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;

        /*
         * Clear out the v_type field to avoid
         * nasty things happening in vgone().
         */
        vp->v_type = VNON;
        return (0);
}

int
fdesc_reclaim(ap)
        struct vnop_reclaim_args /* {
                struct vnode *a_vp;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct fdescnode *fd = VTOFDESC(vp);

        LIST_REMOVE(fd, fd_hash);
        FREE(vp->v_data, M_TEMP);
        vp->v_data = 0;

        return (0);
}

/*
 * Return POSIX pathconf information applicable to special devices.
 */
int
fdesc_pathconf(ap)
        struct vnop_pathconf_args /* {
                struct vnode *a_vp;
                int a_name;
                int *a_retval;
                vfs_context_t a_context;
        } */ *ap;
{

        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = LINK_MAX;
                return (0);
        case _PC_MAX_CANON:
                *ap->a_retval = MAX_CANON;
                return (0);
        case _PC_MAX_INPUT:
                *ap->a_retval = MAX_INPUT;
                return (0);
        case _PC_PIPE_BUF:
                *ap->a_retval = PIPE_BUF;
                return (0);
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                return (0);
        case _PC_VDISABLE:
                *ap->a_retval = _POSIX_VDISABLE;
                return (0);
        default:
                return (EINVAL);
        }
        /* NOTREACHED */
}


/*void*/
int
fdesc_vfree(__unused struct vnop_vfree_args *ap)
{

        return (0);
}

/*
 * /dev/fd "should never get here" operation
 */
int
fdesc_badop(void)
{

        return (ENOTSUP);
        /* NOTREACHED */
}

#define VOPFUNC int (*)(void *)

#define fdesc_create (int (*) (struct  vnop_create_args *))eopnotsupp
#define fdesc_mknod (int (*) (struct  vnop_mknod_args *))eopnotsupp
#define fdesc_close (int (*) (struct  vnop_close_args *))nullop
#define fdesc_access (int (*) (struct  vnop_access_args *))nullop
#define fdesc_mmap (int (*) (struct  vnop_mmap_args *))eopnotsupp
#define fdesc_revoke nop_revoke
#define fdesc_fsync (int (*) (struct  vnop_fsync_args *))nullop
#define fdesc_remove (int (*) (struct  vnop_remove_args *))eopnotsupp
#define fdesc_link (int (*) (struct  vnop_link_args *))eopnotsupp
#define fdesc_rename (int (*) (struct  vnop_rename_args *))eopnotsupp
#define fdesc_mkdir (int (*) (struct  vnop_mkdir_args *))eopnotsupp
#define fdesc_rmdir (int (*) (struct  vnop_rmdir_args *))eopnotsupp
#define fdesc_symlink (int (*) (struct vnop_symlink_args *))eopnotsupp
#define fdesc_strategy (int (*) (struct  vnop_strategy_args *))fdesc_badop
#define fdesc_advlock (int (*) (struct vnop_advlock_args *))eopnotsupp
#define fdesc_bwrite (int (*) (struct  vnop_bwrite_args *))eopnotsupp
#define fdesc_blktooff (int (*) (struct  vnop_blktooff_args *))eopnotsupp
#define fdesc_offtoblk (int (*) (struct  vnop_offtoblk_args *))eopnotsupp
#define fdesc_blockmap (int (*) (struct  vnop_blockmap_args *))eopnotsupp

int (**fdesc_vnodeop_p)(void *);
struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
        { &vnop_default_desc, (VOPFUNC)vn_default_error },
        { &vnop_lookup_desc, (VOPFUNC)fdesc_lookup },   /* lookup */
        { &vnop_create_desc, (VOPFUNC)fdesc_create },   /* create */
        { &vnop_mknod_desc, (VOPFUNC)fdesc_mknod },     /* mknod */
        { &vnop_open_desc, (VOPFUNC)fdesc_open },       /* open */
        { &vnop_close_desc, (VOPFUNC)fdesc_close },     /* close */
        { &vnop_access_desc, (VOPFUNC)fdesc_access },   /* access */
        { &vnop_getattr_desc, (VOPFUNC)fdesc_getattr }, /* getattr */
        { &vnop_setattr_desc, (VOPFUNC)fdesc_setattr }, /* setattr */
        { &vnop_read_desc, (VOPFUNC)fdesc_read },       /* read */
        { &vnop_write_desc, (VOPFUNC)fdesc_write },     /* write */
        { &vnop_ioctl_desc, (VOPFUNC)fdesc_ioctl },     /* ioctl */
        { &vnop_select_desc, (VOPFUNC)fdesc_select },   /* select */
        { &vnop_revoke_desc, (VOPFUNC)fdesc_revoke },   /* revoke */
        { &vnop_mmap_desc, (VOPFUNC)fdesc_mmap },       /* mmap */
        { &vnop_fsync_desc, (VOPFUNC)fdesc_fsync },     /* fsync */
        { &vnop_remove_desc, (VOPFUNC)fdesc_remove },   /* remove */
        { &vnop_link_desc, (VOPFUNC)fdesc_link },       /* link */
        { &vnop_rename_desc, (VOPFUNC)fdesc_rename },   /* rename */
        { &vnop_mkdir_desc, (VOPFUNC)fdesc_mkdir },     /* mkdir */
        { &vnop_rmdir_desc, (VOPFUNC)fdesc_rmdir },     /* rmdir */
        { &vnop_symlink_desc, (VOPFUNC)fdesc_symlink }, /* symlink */
        { &vnop_readdir_desc, (VOPFUNC)fdesc_readdir }, /* readdir */
        { &vnop_readlink_desc, (VOPFUNC)fdesc_readlink },/* readlink */
        { &vnop_inactive_desc, (VOPFUNC)fdesc_inactive },/* inactive */
        { &vnop_reclaim_desc, (VOPFUNC)fdesc_reclaim }, /* reclaim */
        { &vnop_strategy_desc, (VOPFUNC)fdesc_strategy },       /* strategy */
        { &vnop_pathconf_desc, (VOPFUNC)fdesc_pathconf },       /* pathconf */
        { &vnop_advlock_desc, (VOPFUNC)fdesc_advlock }, /* advlock */
        { &vnop_bwrite_desc, (VOPFUNC)fdesc_bwrite },   /* bwrite */
        { &vnop_pagein_desc, (VOPFUNC)err_pagein },     /* pagein */
        { &vnop_pageout_desc, (VOPFUNC)err_pageout },   /* pageout */
        { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
        { &vnop_blktooff_desc, (VOPFUNC)fdesc_blktooff },       /* blktooff */
        { &vnop_blktooff_desc, (VOPFUNC)fdesc_offtoblk },       /* offtoblk */
        { &vnop_blockmap_desc, (VOPFUNC)fdesc_blockmap },       /* blockmap */
        { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
};
struct vnodeopv_desc fdesc_vnodeop_opv_desc =
        { &fdesc_vnodeop_p, fdesc_vnodeop_entries };