/*      $OpenBSD: udf_vnops.c,v 1.75 2024/10/18 05:52:32 miod Exp $     */

/*
 * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/fs/udf/udf_vnops.c,v 1.50 2005/01/28 14:42:16 phk Exp $
 */

/*
 * Ported to OpenBSD by Pedro Martelletto in February 2005.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/pool.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/queue.h>
#include <sys/endian.h>
#include <sys/specdev.h>
#include <sys/unistd.h>

#include <crypto/siphash.h>

#include <isofs/udf/ecma167-udf.h>
#include <isofs/udf/udf.h>
#include <isofs/udf/udf_extern.h>

int udf_bmap_internal(struct unode *, off_t, daddr_t *, uint32_t *);

const struct vops udf_vops = {
        .vop_access     = udf_access,
        .vop_bmap       = udf_bmap,
        .vop_lookup     = udf_lookup,
        .vop_getattr    = udf_getattr,
        .vop_open       = udf_open,
        .vop_close      = udf_close,
        .vop_ioctl      = udf_ioctl,
        .vop_read       = udf_read,
        .vop_readdir    = udf_readdir,
        .vop_readlink   = udf_readlink,
        .vop_inactive   = udf_inactive,
        .vop_reclaim    = udf_reclaim,
        .vop_strategy   = udf_strategy,
        .vop_lock       = udf_lock,
        .vop_unlock     = udf_unlock,
        .vop_pathconf   = udf_pathconf,
        .vop_islocked   = udf_islocked,
        .vop_print      = udf_print,

        .vop_abortop    = NULL,
        .vop_advlock    = NULL,
        .vop_bwrite     = NULL,
        .vop_create     = NULL,
        .vop_fsync      = NULL,
        .vop_link       = NULL,
        .vop_mknod      = NULL,
        .vop_remove     = eopnotsupp,
        .vop_rename     = NULL,
        .vop_revoke     = NULL,
        .vop_mkdir      = NULL,
        .vop_rmdir      = NULL,
        .vop_setattr    = NULL,
        .vop_symlink    = NULL,
        .vop_write      = NULL,
        .vop_kqfilter   = NULL
};

#define UDF_INVALID_BMAP        -1

/* Look up a unode based on the udfino_t passed in and return its vnode */
int
udf_hashlookup(struct umount *ump, udfino_t id, int flags, struct vnode **vpp)
{
        struct unode *up;
        struct udf_hash_lh *lh;
        int error;

        *vpp = NULL;

loop:
        mtx_enter(&ump->um_hashmtx);
        lh = &ump->um_hashtbl[SipHash24(&ump->um_hashkey, &id, sizeof(id)) &
            ump->um_hashsz];
        if (lh == NULL) {
                mtx_leave(&ump->um_hashmtx);
                return (ENOENT);
        }

        LIST_FOREACH(up, lh, u_le) {
                if (up->u_ino == id) {
                        mtx_leave(&ump->um_hashmtx);
                        error = vget(up->u_vnode, flags);
                        if (error == ENOENT)
                                goto loop;
                        if (error)
                                return (error);
                        *vpp = up->u_vnode;
                        return (0);
                }
        }

        mtx_leave(&ump->um_hashmtx);

        return (0);
}

int
udf_hashins(struct unode *up)
{
        struct umount *ump;
        struct udf_hash_lh *lh;

        ump = up->u_ump;

        vn_lock(up->u_vnode, LK_EXCLUSIVE | LK_RETRY);
        mtx_enter(&ump->um_hashmtx);
        lh = &ump->um_hashtbl[SipHash24(&ump->um_hashkey,
            &up->u_ino, sizeof(up->u_ino)) & ump->um_hashsz];
        if (lh == NULL)
                panic("hash entry is NULL, up->u_ino = %d", up->u_ino);
        LIST_INSERT_HEAD(lh, up, u_le);
        mtx_leave(&ump->um_hashmtx);

        return (0);
}

int
udf_hashrem(struct unode *up)
{
        struct umount *ump;
        struct udf_hash_lh *lh;

        ump = up->u_ump;

        mtx_enter(&ump->um_hashmtx);
        lh = &ump->um_hashtbl[SipHash24(&ump->um_hashkey,
            &up->u_ino, sizeof(up->u_ino)) & ump->um_hashsz];
        if (lh == NULL)
                panic("hash entry is NULL, up->u_ino = %d", up->u_ino);
        LIST_REMOVE(up, u_le);
        mtx_leave(&ump->um_hashmtx);

        return (0);
}

int
udf_allocv(struct mount *mp, struct vnode **vpp, struct proc *p)
{
        int error;
        struct vnode *vp;

        error = getnewvnode(VT_UDF, mp, &udf_vops, &vp);
        if (error) {
                printf("udf_allocv: failed to allocate new vnode\n");
                return (error);
        }

        *vpp = vp;
        return (0);
}

/* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
static mode_t
udf_permtomode(struct unode *up)
{
        uint32_t perm;
        uint16_t flags;
        mode_t mode;

        perm = letoh32(up->u_fentry->perm);
        flags = letoh16(up->u_fentry->icbtag.flags);

        mode = perm & UDF_FENTRY_PERM_USER_MASK;
        mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
        mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
        mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
        mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
        mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);

        return (mode);
}

int
udf_access(void *v)
{
        struct vop_access_args *ap = v;
        struct vnode *vp;
        struct unode *up;
        mode_t a_mode, mode;

        vp = ap->a_vp;
        up = VTOU(vp);
        a_mode = ap->a_mode;

        if (a_mode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        return (EROFS);
                        /* NOTREACHED */
                default:
                        break;
                }
        }

        mode = udf_permtomode(up);

        return (vaccess(vp->v_type, mode, up->u_fentry->uid, up->u_fentry->gid,
            a_mode, ap->a_cred));
}

static int mon_lens[2][12] = {
        {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
        {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
};

static int
udf_isaleapyear(int year)
{
        int i;

        i = (year % 4) ? 0 : 1;
        i &= (year % 100) ? 1 : 0;
        i |= (year % 400) ? 0 : 1;

        return (i);
}

/*
 * This is just a rough hack.  Daylight savings isn't calculated and tv_nsec
 * is ignored.
 * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
 */
static void
udf_timetotimespec(struct timestamp *time, struct timespec *t)
{
        int i, lpyear, daysinyear, year;
        union {
                uint16_t        u_tz_offset;
                int16_t         s_tz_offset;
        } tz;

        /* DirectCD seems to like using bogus year values */
        year = letoh16(time->year);
        if (year < 1970) {
                t->tv_sec = 0;
                t->tv_nsec = 0;
                return;
        }

        /* Calculate the time and day */
        t->tv_nsec = 1000 * time->usec + 100000 * time->hund_usec
            + 10000000 * time->centisec;
        t->tv_sec = time->second;
        t->tv_sec += time->minute * 60;
        t->tv_sec += time->hour * 3600;
        t->tv_sec += time->day * 3600 * 24;

        /* Calculate the month */
        lpyear = udf_isaleapyear(year);
        for (i = 1; i < time->month; i++)
                t->tv_sec += mon_lens[lpyear][i] * 3600 * 24;

        /* Speed up the calculation */
        if (year > 1979)
                t->tv_sec += 315532800;
        if (year > 1989)
                t->tv_sec += 315619200;
        if (year > 1999)
                t->tv_sec += 315532800;
        for (i = 2000; i < year; i++) {
                daysinyear = udf_isaleapyear(i) + 365 ;
                t->tv_sec += daysinyear * 3600 * 24;
        }

        /*
         * Calculate the time zone.  The timezone is 12 bit signed 2's
         * compliment, so we gotta do some extra magic to handle it right.
         */
        tz.u_tz_offset = letoh16(time->type_tz);
        tz.u_tz_offset &= 0x0fff;
        if (tz.u_tz_offset & 0x0800)
                tz.u_tz_offset |= 0xf000;       /* extend the sign to 16 bits */
        if ((time->type_tz & 0x1000) && (tz.s_tz_offset != -2047))
                t->tv_sec -= tz.s_tz_offset * 60;

        return;
}

int
udf_getattr(void *v)
{
        struct vop_getattr_args *ap = v;
        struct vnode *vp;
        struct unode *up;
        struct vattr *vap;
        struct extfile_entry *xfentry;
        struct file_entry *fentry;
        struct timespec ts;

        ts.tv_sec = 0;

        vp = ap->a_vp;
        vap = ap->a_vap;
        up = VTOU(vp);

        xfentry = up->u_fentry;
        fentry = (struct file_entry *)up->u_fentry;

        vap->va_fsid = up->u_dev;
        vap->va_fileid = up->u_ino;
        vap->va_mode = udf_permtomode(up);
        vap->va_nlink = letoh16(fentry->link_cnt);
        /*
         * The spec says that -1 is valid for uid/gid and indicates an
         * invalid uid/gid.  How should this be represented?
         */
        vap->va_uid = (letoh32(fentry->uid) == -1) ? 0 : letoh32(fentry->uid);
        vap->va_gid = (letoh32(fentry->gid) == -1) ? 0 : letoh32(fentry->gid);
        vap->va_rdev = 0;
        if (vp->v_type & VDIR) {
                vap->va_nlink++; /* Count a reference to ourselves */
                /*
                 * Directories that are recorded within their ICB will show
                 * as having 0 blocks recorded.  Since tradition dictates
                 * that directories consume at least one logical block,
                 * make it appear so.
                 */
                vap->va_size = up->u_ump->um_bsize;
        } else
                vap->va_size = letoh64(fentry->inf_len);
        if (udf_checktag(&xfentry->tag, TAGID_EXTFENTRY) == 0) {
                udf_timetotimespec(&xfentry->atime, &vap->va_atime);
                udf_timetotimespec(&xfentry->mtime, &vap->va_mtime);
                if ((vp->v_type & VDIR) && xfentry->logblks_rec != 0)
                        vap->va_size =
                                    letoh64(xfentry->logblks_rec) * up->u_ump->um_bsize;
        } else {
                udf_timetotimespec(&fentry->atime, &vap->va_atime);
                udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
                if ((vp->v_type & VDIR) && fentry->logblks_rec != 0)
                        vap->va_size =
                                    letoh64(fentry->logblks_rec) * up->u_ump->um_bsize;
        }
        vap->va_ctime = vap->va_mtime; /* Stored as an Extended Attribute */
        vap->va_flags = 0;
        vap->va_gen = 1;
        vap->va_blocksize = up->u_ump->um_bsize;
        vap->va_bytes = letoh64(fentry->inf_len);
        vap->va_type = vp->v_type;
        vap->va_filerev = 0;

        return (0);
}

int
udf_open(void *v)
{
        return (0); /* Nothing to be done at this point */
}

int
udf_close(void *v)
{
        return (0); /* Nothing to be done at this point */
}

/*
 * File specific ioctls.
 */
int
udf_ioctl(void *v)
{
        return (ENOTTY);
}

/*
 * I'm not sure that this has much value in a read-only filesystem, but
 * cd9660 has it too.
 */
int
udf_pathconf(void *v)
{
        struct vop_pathconf_args *ap = v;
        int error = 0;

        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = 65535;
                break;
        case _PC_NAME_MAX:
                *ap->a_retval = NAME_MAX;
                break;
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                break;
        case _PC_NO_TRUNC:
                *ap->a_retval = 1;
                break;
        case _PC_TIMESTAMP_RESOLUTION:
                *ap->a_retval = 1000;           /* 1 microsecond */
                break;
        default:
                error = EINVAL;
                break;
        }

        return (error);
}

int
udf_read(void *v)
{
        struct vop_read_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
        struct unode *up = VTOU(vp);
        struct buf *bp;
        uint8_t *data;
        off_t fsize, offset;
        int error = 0;
        int size;

        if (uio->uio_offset < 0)
                return (EINVAL);

        fsize = letoh64(up->u_fentry->inf_len);

        while (uio->uio_offset < fsize && uio->uio_resid > 0) {
                offset = uio->uio_offset;
                size = ulmin(uio->uio_resid, MAXBSIZE);
                if (size > fsize - offset)
                        size = fsize - offset;
                error = udf_readatoffset(up, &size, offset, &bp, &data);
                if (error == 0)
                        error = uiomove(data, (size_t)size, uio);
                if (bp != NULL) {
                        brelse(bp);
                        bp = NULL;
                }
                if (error)
                        break;
        }

        return (error);
}

/*
 * Translate the name from a CS0 dstring to a 16-bit Unicode String.
 * Hooks need to be placed in here to translate from Unicode to the encoding
 * that the kernel/user expects.  Return the length of the translated string.
 */
int
udf_transname(char *cs0string, char *destname, int len, struct umount *ump)
{
        unicode_t *transname;
        int i, unilen = 0, destlen;

        if (len > MAXNAMLEN) {
#ifdef DIAGNOSTIC
                printf("udf_transname(): name too long\n");
#endif
                return (0);
        }

        /* allocate a buffer big enough to hold an 8->16 bit expansion */
        transname = pool_get(&udf_trans_pool, PR_WAITOK);

        if ((unilen = udf_rawnametounicode(len, cs0string, transname)) == -1) {
#ifdef DIAGNOSTIC
                printf("udf_transname(): Unicode translation failed\n");
#endif
                pool_put(&udf_trans_pool, transname);
                return (0);
        }

        /* Pack it back to 8-bit Unicode. */
        for (i = 0; i < unilen ; i++)
                if (transname[i] & 0xff00)
                        destname[i] = '?';      /* Fudge the 16bit chars */
                else
                        destname[i] = transname[i] & 0xff;

        pool_put(&udf_trans_pool, transname);

        /* Don't forget to terminate the string. */
        destname[unilen] = 0;
        destlen = unilen;

        return (destlen);
}

/*
 * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
 * 0 on a successful match, nonzero otherwise.  Unicode work may need to be
 * done here also.
 */
static int
udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct umount *ump)
{
        char *transname;
        int error = 0;

        /* This is overkill, but not worth creating a new pool */
        transname = pool_get(&udf_trans_pool, PR_WAITOK);

        cs0len = udf_transname(cs0string, transname, cs0len, ump);

        /* Easy check.  If they aren't the same length, they aren't equal */
        if ((cs0len == 0) || (cs0len != cmplen))
                error = -1;
        else
                error = bcmp(transname, cmpname, cmplen);

        pool_put(&udf_trans_pool, transname);

        return (error);
}

struct udf_uiodir {
        struct dirent *dirent;
        int eofflag;
};

static int
udf_uiodir(struct udf_uiodir *uiodir, struct uio *uio, long off)
{
        size_t de_size = DIRENT_SIZE(uiodir->dirent);

        if (uio->uio_resid < de_size) {
                uiodir->eofflag = 0;
                return (-1);
        }
        uiodir->dirent->d_off = off;
        uiodir->dirent->d_reclen = de_size;

        if (memchr(uiodir->dirent->d_name, '/',
            uiodir->dirent->d_namlen) != NULL) {
                /* illegal file name */
                return (EINVAL);
        }

        return (uiomove(uiodir->dirent, de_size, uio));
}

static struct udf_dirstream *
udf_opendir(struct unode *up, int offset, int fsize, struct umount *ump)
{
        struct udf_dirstream *ds;

        ds = pool_get(&udf_ds_pool, PR_WAITOK | PR_ZERO);

        ds->node = up;
        ds->offset = offset;
        ds->ump = ump;
        ds->fsize = fsize;

        return (ds);
}

static struct fileid_desc *
udf_getfid(struct udf_dirstream *ds)
{
        struct fileid_desc *fid;
        int error, frag_size = 0, total_fid_size;

        /* End of directory? */
        if (ds->offset + ds->off >= ds->fsize) {
                ds->error = 0;
                return (NULL);
        }

        /* Grab the first extent of the directory */
        if (ds->off == 0) {
                ds->size = 0;
                error = udf_readatoffset(ds->node, &ds->size, ds->offset,
                    &ds->bp, &ds->data);
                if (error) {
                        ds->error = error;
                        if (ds->bp != NULL) {
                                brelse(ds->bp);
                                ds->bp = NULL;
                        }
                        return (NULL);
                }
        }

        /*
         * Clean up from a previous fragmented FID.
         * Is this the right place for this?
         */
        if (ds->fid_fragment && ds->buf != NULL) {
                ds->fid_fragment = 0;
                free(ds->buf, M_UDFFID, 0);
        }

        fid = (struct fileid_desc*)&ds->data[ds->off];

        /*
         * Check to see if the fid is fragmented. The first test
         * ensures that we don't wander off the end of the buffer
         * looking for the l_iu and l_fi fields.
         */
        if (ds->off + UDF_FID_SIZE > ds->size ||
            ds->off + letoh16(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){

                /* Copy what we have of the fid into a buffer */
                frag_size = ds->size - ds->off;
                if (frag_size >= ds->ump->um_bsize) {
                        printf("udf: invalid FID fragment\n");
                        ds->error = EINVAL;
                        return (NULL);
                }

                /*
                 * File ID descriptors can only be at most one
                 * logical sector in size.
                 */
                ds->buf = malloc(ds->ump->um_bsize, M_UDFFID, M_WAITOK|M_ZERO);
                bcopy(fid, ds->buf, frag_size);

                /* Reduce all of the casting magic */
                fid = (struct fileid_desc*)ds->buf;

                if (ds->bp != NULL) {
                        brelse(ds->bp);
                        ds->bp = NULL;
                }

                /* Fetch the next allocation */
                ds->offset += ds->size;
                ds->size = 0;
                error = udf_readatoffset(ds->node, &ds->size, ds->offset,
                    &ds->bp, &ds->data);
                if (error) {
                        ds->error = error;
                        if (ds->bp != NULL) {
                                brelse(ds->bp);
                                ds->bp = NULL;
                        }
                        return (NULL);
                }

                /*
                 * If the fragment was so small that we didn't get
                 * the l_iu and l_fi fields, copy those in.
                 */
                if (frag_size < UDF_FID_SIZE)
                        bcopy(ds->data, &ds->buf[frag_size],
                            UDF_FID_SIZE - frag_size);

                /*
                 * Now that we have enough of the fid to work with,
                 * copy in the rest of the fid from the new
                 * allocation.
                 */
                total_fid_size = UDF_FID_SIZE + letoh16(fid->l_iu) + fid->l_fi;
                if (total_fid_size > ds->ump->um_bsize) {
                        printf("udf: invalid FID\n");
                        ds->error = EIO;
                        return (NULL);
                }
                bcopy(ds->data, &ds->buf[frag_size],
                    total_fid_size - frag_size);

                ds->fid_fragment = 1;
        } else {
                total_fid_size = letoh16(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
        }

        /*
         * Update the offset. Align on a 4 byte boundary because the
         * UDF spec says so.
         */
        if (!ds->fid_fragment) {
                ds->off += (total_fid_size + 3) & ~0x03;
        } else {
                ds->off = (total_fid_size - frag_size + 3) & ~0x03;
        }
        ds->this_off = ds->offset + ds->off;

        return (fid);
}

static void
udf_closedir(struct udf_dirstream *ds)
{

        if (ds->bp != NULL) {
                brelse(ds->bp);
                ds->bp = NULL;
        }

        if (ds->fid_fragment && ds->buf != NULL)
                free(ds->buf, M_UDFFID, 0);

        pool_put(&udf_ds_pool, ds);
}

#define SELF_OFFSET     1
#define PARENT_OFFSET   2

int
udf_readdir(void *v)
{
        struct vop_readdir_args *ap = v;
        struct vnode *vp;
        struct uio *uio;
        struct dirent dir;
        struct unode *up;
        struct umount *ump;
        struct fileid_desc *fid;
        struct udf_uiodir uiodir;
        struct udf_dirstream *ds;
        off_t last_off;
        enum { MODE_NORMAL, MODE_SELF, MODE_PARENT } mode;
        int error = 0;

        vp = ap->a_vp;
        uio = ap->a_uio;
        up = VTOU(vp);
        ump = up->u_ump;
        uiodir.eofflag = 1;
        uiodir.dirent = &dir;
        memset(&dir, 0, sizeof(dir));

        /*
         * if asked to start at SELF_OFFSET or PARENT_OFFSET, search
         * for the parent ref
         */
        if (uio->uio_offset == SELF_OFFSET) {
                mode = MODE_SELF;
                uio->uio_offset = 0;
        } else if (uio->uio_offset == PARENT_OFFSET) {
                mode = MODE_PARENT;
                uio->uio_offset = 0;
        } else
                mode = MODE_NORMAL;

        /*
         * Iterate through the file id descriptors.  Give the parent dir
         * entry special attention.
         */
        if (ISSET(up->u_ump->um_flags, UDF_MNT_USES_META)) {
                up->u_ump->um_start += up->u_ump->um_meta_start;
                up->u_ump->um_len = up->u_ump->um_meta_len;
        }
        ds = udf_opendir(up, uio->uio_offset,
            letoh64(up->u_fentry->inf_len), up->u_ump);

        last_off = ds->offset + ds->off;
        while ((fid = udf_getfid(ds)) != NULL) {

                /* Should we return an error on a bad fid? */
                if (udf_checktag(&fid->tag, TAGID_FID)) {
                        printf("Invalid FID tag (%d)\n", fid->tag.id);
                        error = EIO;
                        break;
                }

                /* Is this a deleted file? */
                if (fid->file_char & UDF_FILE_CHAR_DEL)
                        continue;

                if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
                        /* Do up the '.' and '..' entries.  Dummy values are
                         * used for the offset since the offset here is
                         * usually zero, and NFS doesn't like that value
                         */
                        if (mode == MODE_NORMAL) {
                                dir.d_fileno = up->u_ino;
                                dir.d_type = DT_DIR;
                                dir.d_name[0] = '.';
                                dir.d_name[1] = '\0';
                                dir.d_namlen = 1;
                                error = udf_uiodir(&uiodir, uio, SELF_OFFSET);
                                if (error)
                                        break;
                        }
                        if (mode != MODE_PARENT) {
                                dir.d_fileno = udf_getid(&fid->icb);
                                dir.d_type = DT_DIR;
                                dir.d_name[0] = '.';
                                dir.d_name[1] = '.';
                                dir.d_name[2] = '\0';
                                dir.d_namlen = 2;
                                error = udf_uiodir(&uiodir, uio, PARENT_OFFSET);
                        }
                        mode = MODE_NORMAL;
                } else if (mode != MODE_NORMAL) {
                        continue;
                } else {
                        dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
                            &dir.d_name[0], fid->l_fi, ump);
                        dir.d_fileno = udf_getid(&fid->icb);
                        dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
                            DT_DIR : DT_UNKNOWN;
                        error = udf_uiodir(&uiodir, uio, ds->this_off);
                }
                if (error) {
                        /*
                         * udf_uiodir() indicates there isn't space for
                         * another entry by returning -1
                         */
                        if (error == -1)
                                error = 0;
                        break;
                }
                last_off = ds->this_off;
        }

        /* tell the calling layer whether we need to be called again */
        *ap->a_eofflag = uiodir.eofflag;
        uio->uio_offset = last_off;

        if (!error)
                error = ds->error;

        udf_closedir(ds);
        if (ISSET(up->u_ump->um_flags, UDF_MNT_USES_META)) {
                up->u_ump->um_start = up->u_ump->um_realstart;
                up->u_ump->um_len = up->u_ump->um_reallen;
        }

        return (error);
}

/* Are there any implementations out there that do soft-links? */
int
udf_readlink(void *v)
{
        return (EOPNOTSUPP);
}

int
udf_strategy(void *v)
{
        struct vop_strategy_args *ap = v;
        struct buf *bp;
        struct vnode *vp;
        struct unode *up;
        int maxsize, s, error;

        bp = ap->a_bp;
        vp = bp->b_vp;
        up = VTOU(vp);

        /* cd9660 has this test reversed, but it seems more logical this way */
        if (bp->b_blkno != bp->b_lblkno) {
                /*
                 * Files that are embedded in the fentry don't translate well
                 * to a block number.  Reject.
                 */
                if (udf_bmap_internal(up, bp->b_lblkno * up->u_ump->um_bsize,
                    &bp->b_lblkno, &maxsize)) {
                        clrbuf(bp);
                        bp->b_blkno = -1;
                }
        } else {
                error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL);
                if (error) {
                        bp->b_error = error;
                        bp->b_flags |= B_ERROR;
                        s = splbio();
                        biodone(bp);
                        splx(s);
                        return (error);
                }

                if ((long)bp->b_blkno == -1)
                        clrbuf(bp);
        }

        if ((long)bp->b_blkno == -1) {
                s = splbio();
                biodone(bp);
                splx(s);
        } else {
                bp->b_dev = vp->v_rdev;
                VOP_STRATEGY(up->u_devvp, bp);
        }

        return (0);
}

int
udf_lock(void *v)
{
        struct vop_lock_args *ap = v;
        struct vnode *vp = ap->a_vp;

        return rrw_enter(&VTOU(vp)->u_lock, ap->a_flags & LK_RWFLAGS);
}

int
udf_unlock(void *v)
{
        struct vop_unlock_args *ap = v;
        struct vnode *vp = ap->a_vp;

        rrw_exit(&VTOU(vp)->u_lock);
        return 0;
}

int
udf_islocked(void *v)
{
        struct vop_islocked_args *ap = v;

        return rrw_status(&VTOU(ap->a_vp)->u_lock);
}

int
udf_print(void *v)
{
#if defined(DEBUG) || defined(DIAGNOSTIC) || defined(VFSLCKDEBUG)
        struct vop_print_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct unode *up = VTOU(vp);

        /*
         * Complete the information given by vprint().
         */
        printf("tag VT_UDF, hash id %u\n", up->u_ino);
#ifdef DIAGNOSTIC
        printf("\n");
#endif
#endif
        return (0);
}

int
udf_bmap(void *v)
{
        struct vop_bmap_args *ap = v;
        struct unode *up;
        uint32_t max_size;
        daddr_t lsector;
        int error;

        up = VTOU(ap->a_vp);

        if (ap->a_vpp != NULL)
                *ap->a_vpp = up->u_devvp;
        if (ap->a_bnp == NULL)
                return (0);

        error = udf_bmap_internal(up, ap->a_bn * up->u_ump->um_bsize,
            &lsector, &max_size);
        if (error)
                return (error);

        /* Translate logical to physical sector number */
        *ap->a_bnp = lsector << (up->u_ump->um_bshift - DEV_BSHIFT);

        /* Punt on read-ahead for now */
        if (ap->a_runp)
                *ap->a_runp = 0;

        return (0);
}

/*
 * The all powerful VOP_LOOKUP().
 */
int
udf_lookup(void *v)
{
        struct vop_lookup_args *ap = v;
        struct vnode *dvp;
        struct vnode *tdp = NULL;
        struct vnode **vpp = ap->a_vpp;
        struct unode *up;
        struct umount *ump;
        struct fileid_desc *fid = NULL;
        struct udf_dirstream *ds;
        struct proc *p;
        u_long nameiop;
        u_long flags;
        char *nameptr;
        long namelen;
        udfino_t id = 0;
        int offset, error = 0;
        int numdirpasses, fsize;

        extern struct nchstats nchstats;

        dvp = ap->a_dvp;
        up = VTOU(dvp);
        ump = up->u_ump;
        nameiop = ap->a_cnp->cn_nameiop;
        flags = ap->a_cnp->cn_flags;
        nameptr = ap->a_cnp->cn_nameptr;
        namelen = ap->a_cnp->cn_namelen;
        fsize = letoh64(up->u_fentry->inf_len);
        p = ap->a_cnp->cn_proc;
        *vpp = NULL;

        /*
         * Make sure the process can scan the requested directory.
         */
        error = VOP_ACCESS(dvp, VEXEC, ap->a_cnp->cn_cred, p);
        if (error)
                return (error);

        /*
         * Check if the (directory, name) tuple has been already cached.
         */
        error = cache_lookup(dvp, vpp, ap->a_cnp);
        if (error >= 0)
                return (error);
        else
                error = 0;

        /*
         * If dvp is what's being looked up, then return it.
         */
        if (ap->a_cnp->cn_namelen == 1 && ap->a_cnp->cn_nameptr[0] == '.') {
                vref(dvp);
                *vpp = dvp;
                return (0);
        }

        /*
         * If this is a LOOKUP and we've already partially searched through
         * the directory, pick up where we left off and flag that the
         * directory may need to be searched twice.  For a full description,
         * see /sys/isofs/cd9660/cd9660_lookup.c:cd9660_lookup()
         */
        if (nameiop != LOOKUP || up->u_diroff == 0 || up->u_diroff > fsize) {
                offset = 0;
                numdirpasses = 1;
        } else {
                offset = up->u_diroff;
                numdirpasses = 2;
                nchstats.ncs_2passes++;
        }

        if (ISSET(up->u_ump->um_flags, UDF_MNT_USES_META)) {
                up->u_ump->um_start += up->u_ump->um_meta_start;
                up->u_ump->um_len = up->u_ump->um_meta_len;
        }
lookloop:
        ds = udf_opendir(up, offset, fsize, ump);

        while ((fid = udf_getfid(ds)) != NULL) {
                /* Check for a valid FID tag. */
                if (udf_checktag(&fid->tag, TAGID_FID)) {
                        printf("udf_lookup: Invalid tag\n");
                        error = EIO;
                        break;
                }

                /* Is this a deleted file? */
                if (fid->file_char & UDF_FILE_CHAR_DEL)
                        continue;

                if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
                        if (flags & ISDOTDOT) {
                                id = udf_getid(&fid->icb);
                                break;
                        }
                } else {
                        if (!(udf_cmpname(&fid->data[fid->l_iu],
                            nameptr, fid->l_fi, namelen, ump))) {
                                id = udf_getid(&fid->icb);
                                break;
                        }
                }
        }

        if (!error)
                error = ds->error;

        if (error) {
                udf_closedir(ds);
                if (ISSET(up->u_ump->um_flags, UDF_MNT_USES_META)) {
                        up->u_ump->um_start = up->u_ump->um_realstart;
                        up->u_ump->um_len = up->u_ump->um_reallen;
                }
                return (error);
        }

        /* Did we have a match? */
        if (id) {
                error = udf_vget(ump->um_mountp, id, &tdp);
                if (!error) {
                        /*
                         * Remember where this entry was if it's the final
                         * component.
                         */
                        if ((flags & ISLASTCN) && nameiop == LOOKUP)
                                up->u_diroff = ds->offset + ds->off;
                        if (numdirpasses == 2)
                                nchstats.ncs_pass2++;
                        if (!(flags & LOCKPARENT) || !(flags & ISLASTCN)) {
                                ap->a_cnp->cn_flags |= PDIRUNLOCK;
                                VOP_UNLOCK(dvp);
                        }

                        *vpp = tdp;
                }
        } else {
                /* Name wasn't found on this pass.  Do another pass? */
                if (numdirpasses == 2) {
                        numdirpasses--;
                        offset = 0;
                        udf_closedir(ds);
                        goto lookloop;
                }

                if ((flags & ISLASTCN) &&
                    (nameiop == CREATE || nameiop == RENAME)) {
                        error = EROFS;
                } else {
                        error = ENOENT;
                }
        }

        /*
         * Cache the result of this lookup.
         */
        if (flags & MAKEENTRY)
                cache_enter(dvp, *vpp, ap->a_cnp);

        udf_closedir(ds);
        if (ISSET(up->u_ump->um_flags, UDF_MNT_USES_META)) {
                up->u_ump->um_start = up->u_ump->um_realstart;
                up->u_ump->um_len = up->u_ump->um_reallen;
        }

        return (error);
}

int
udf_inactive(void *v)
{
        struct vop_inactive_args *ap = v;
        struct vnode *vp = ap->a_vp;

        /*
         * No need to sync anything, so just unlock the vnode and return.
         */
        VOP_UNLOCK(vp);

        return (0);
}

int
udf_reclaim(void *v)
{
        struct vop_reclaim_args *ap = v;
        struct vnode *vp;
        struct unode *up;

        vp = ap->a_vp;
        up = VTOU(vp);

        if (up != NULL) {
                udf_hashrem(up);
                if (up->u_devvp) {
                        vrele(up->u_devvp);
                        up->u_devvp = 0;
                }

                if (up->u_fentry != NULL)
                        free(up->u_fentry, M_UDFFENTRY, 0);

                pool_put(&unode_pool, up);
                vp->v_data = NULL;
        }
        
        return (0);
}

/*
 * Read the block and then set the data pointer to correspond with the
 * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
 * to the number of bytes pointed to.  If 'size' is zero, try to read in a
 * whole extent.
 *
 * Note that *bp may be assigned error or not.
 *
 */
int
udf_readatoffset(struct unode *up, int *size, off_t offset,
    struct buf **bp, uint8_t **data)
{
        struct umount *ump;
        struct extfile_entry *xfentry = NULL;
        struct file_entry *fentry = NULL;
        struct buf *bp1;
        uint32_t max_size;
        daddr_t sector;
        int error;

        ump = up->u_ump;

        *bp = NULL;
        error = udf_bmap_internal(up, offset, &sector, &max_size);
        if (error == UDF_INVALID_BMAP) {
                /*
                 * This error means that the file *data* is stored in the
                 * allocation descriptor field of the file entry.
                 */
                if (udf_checktag(&up->u_fentry->tag, TAGID_EXTFENTRY) == 0) {
                        xfentry = up->u_fentry;
                        *data = &xfentry->data[letoh32(xfentry->l_ea)];
                        *size = letoh32(xfentry->l_ad);
                } else {
                        fentry = (struct file_entry *)up->u_fentry;
                        *data = &fentry->data[letoh32(fentry->l_ea)];
                        *size = letoh32(fentry->l_ad);
                }
                return (0);
        } else if (error != 0) {
                return (error);
        }

        /* Adjust the size so that it is within range */
        if (*size == 0 || *size > max_size)
                *size = max_size;
        *size = min(*size, MAXBSIZE);

        if ((error = udf_readlblks(ump, sector, *size, bp))) {
                printf("warning: udf_readlblks returned error %d\n", error);
                /* note: *bp may be non-NULL */
                return (error);
        }

        bp1 = *bp;
        *data = (uint8_t *)&bp1->b_data[offset % ump->um_bsize];
        return (0);
}

/*
 * Translate a file offset into a logical block and then into a physical
 * block.
 */
int
udf_bmap_internal(struct unode *up, off_t offset, daddr_t *sector,
    uint32_t *max_size)
{
        struct umount *ump;
        struct extfile_entry *xfentry;
        struct file_entry *fentry;
        void *icb;
        struct icb_tag *tag;
        uint32_t icblen = 0;
        daddr_t lsector;
        int ad_offset, ad_num = 0;
        int i, p_offset, l_ea, l_ad;

        ump = up->u_ump;
        xfentry = up->u_fentry;
        fentry = (struct file_entry *)up->u_fentry;
        tag = &fentry->icbtag;
        if (udf_checktag(&xfentry->tag, TAGID_EXTFENTRY) == 0) {
                l_ea = letoh32(xfentry->l_ea);
                l_ad = letoh32(xfentry->l_ad);
        } else {
                l_ea = letoh32(fentry->l_ea);
                l_ad = letoh32(fentry->l_ad);
        }

        switch (letoh16(tag->strat_type)) {
        case 4:
                break;

        case 4096:
                printf("Cannot deal with strategy4096 yet!\n");
                return (ENODEV);

        default:
                printf("Unknown strategy type %d\n", tag->strat_type);
                return (ENODEV);
        }

        switch (letoh16(tag->flags) & 0x7) {
        case 0:
                /*
                 * The allocation descriptor field is filled with short_ad's.
                 * If the offset is beyond the current extent, look for the
                 * next extent.
                 */
                do {
                        offset -= icblen;
                        ad_offset = sizeof(struct short_ad) * ad_num;
                        if (ad_offset > l_ad) {
                                printf("SFile offset out of bounds (%d > %d)\n",
                                    ad_offset, l_ad);
                                return (EINVAL);
                        }
                        
                        if (udf_checktag(&up->u_fentry->tag, TAGID_EXTFENTRY) == 0)
                                icb = GETICB(short_ad, xfentry, l_ea + ad_offset);
                        else
                                icb = GETICB(short_ad, fentry, l_ea + ad_offset);

                        icblen = GETICBLEN(short_ad, icb);
                        ad_num++;
                } while(offset >= icblen);

                lsector = (offset  >> ump->um_bshift) +
                    letoh32(((struct short_ad *)(icb))->lb_num);

                *max_size = GETICBLEN(short_ad, icb);

                break;
        case 1:
                /*
                 * The allocation descriptor field is filled with long_ad's
                 * If the offset is beyond the current extent, look for the
                 * next extent.
                 */
                do {
                        offset -= icblen;
                        ad_offset = sizeof(struct long_ad) * ad_num;
                        if (ad_offset > l_ad) {
                                printf("LFile offset out of bounds (%d > %d)\n",
                                    ad_offset, l_ad);
                                return (EINVAL);
                        }
                        if (udf_checktag(&up->u_fentry->tag, TAGID_EXTFENTRY) == 0)
                                icb = GETICB(long_ad, xfentry, l_ea + ad_offset);
                        else
                                icb = GETICB(long_ad, fentry, l_ea + ad_offset);
                        icblen = GETICBLEN(long_ad, icb);
                        ad_num++;
                } while(offset >= icblen);

                lsector = (offset >> ump->um_bshift) +
                    letoh32(((struct long_ad *)(icb))->loc.lb_num);

                *max_size = GETICBLEN(long_ad, icb);

                break;
        case 3:
                /*
                 * This type means that the file *data* is stored in the
                 * allocation descriptor field of the file entry.
                 */
                *max_size = 0;
                *sector = up->u_ino + ump->um_start;

                return (UDF_INVALID_BMAP);
        case 2:
                /* DirectCD does not use extended_ad's */
        default:
                printf("Unsupported allocation descriptor %d\n",
                       tag->flags & 0x7);
                return (ENODEV);
        }

        *sector = lsector + ump->um_start;

        /*
         * Check the sparing table.  Each entry represents the beginning of
         * a packet.
         */
        if (ump->um_stbl != NULL) {
                for (i = 0; i< ump->um_stbl_len; i++) {
                        p_offset =
                            lsector - letoh32(ump->um_stbl->entries[i].org);
                        if ((p_offset < ump->um_psecs) && (p_offset >= 0)) {
                                *sector =
                                   letoh32(ump->um_stbl->entries[i].map) +
                                    p_offset;
                                break;
                        }
                }
        }

        return (0);
}