/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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.
 */

/* udf_vnops.c */
/* Take care of the vnode side of things */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <sys/bio.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/iconv.h>
#include <sys/limits.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/queue.h>
#include <sys/unistd.h>
#include <sys/endian.h>

#include <vm/uma.h>

#include <fs/udf/ecma167-udf.h>
#include <fs/udf/osta.h>
#include <fs/udf/udf.h>
#include <fs/udf/udf_mount.h>

extern struct iconv_functions *udf_iconv;

static vop_access_t     udf_access;
static vop_getattr_t    udf_getattr;
static vop_open_t       udf_open;
static vop_ioctl_t      udf_ioctl;
static vop_pathconf_t   udf_pathconf;
static vop_print_t      udf_print;
static vop_read_t       udf_read;
static vop_readdir_t    udf_readdir;
static vop_readlink_t   udf_readlink;
static vop_setattr_t    udf_setattr;
static vop_strategy_t   udf_strategy;
static vop_bmap_t       udf_bmap;
static vop_cachedlookup_t       udf_lookup;
static vop_reclaim_t    udf_reclaim;
static vop_vptofh_t     udf_vptofh;
static int udf_readatoffset(struct udf_node *node, int *size, off_t offset,
    struct buf **bp, uint8_t **data);
static int udf_bmap_internal(struct udf_node *node, off_t offset,
    daddr_t *sector, uint32_t *max_size);

static struct vop_vector udf_vnodeops = {
        .vop_default =          &default_vnodeops,

        .vop_access =           udf_access,
        .vop_bmap =             udf_bmap,
        .vop_cachedlookup =     udf_lookup,
        .vop_getattr =          udf_getattr,
        .vop_ioctl =            udf_ioctl,
        .vop_lookup =           vfs_cache_lookup,
        .vop_open =             udf_open,
        .vop_pathconf =         udf_pathconf,
        .vop_print =            udf_print,
        .vop_read =             udf_read,
        .vop_readdir =          udf_readdir,
        .vop_readlink =         udf_readlink,
        .vop_reclaim =          udf_reclaim,
        .vop_setattr =          udf_setattr,
        .vop_strategy =         udf_strategy,
        .vop_vptofh =           udf_vptofh,
};
VFS_VOP_VECTOR_REGISTER(udf_vnodeops);

struct vop_vector udf_fifoops = {
        .vop_default =          &fifo_specops,
        .vop_access =           udf_access,
        .vop_getattr =          udf_getattr,
        .vop_pathconf =         udf_pathconf,
        .vop_print =            udf_print,
        .vop_reclaim =          udf_reclaim,
        .vop_setattr =          udf_setattr,
        .vop_vptofh =           udf_vptofh,
};
VFS_VOP_VECTOR_REGISTER(udf_fifoops);

static MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
static MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");

#define UDF_INVALID_BMAP        -1

int
udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
{
        int error;
        struct vnode *vp;

        error = getnewvnode("udf", mp, &udf_vnodeops, &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 udf_node *node)
{
        uint32_t perm;
        uint16_t flags;
        mode_t mode;

        perm = le32toh(node->fentry->perm);
        flags = le16toh(node->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);
}

static int
udf_access(struct vop_access_args *a)
{
        struct vnode *vp;
        struct udf_node *node;
        accmode_t accmode;
        mode_t mode;

        vp = a->a_vp;
        node = VTON(vp);
        accmode = a->a_accmode;

        if (accmode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        return (EROFS);
                        /* NOT REACHED */
                default:
                        break;
                }
        }

        mode = udf_permtomode(node);

        return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
            accmode, a->a_cred));
}

static int
udf_open(struct vop_open_args *ap)
{
        struct udf_node *np = VTON(ap->a_vp);
        uint64_t fsize;

        fsize = le64toh(np->fentry->inf_len);
        if (fsize > OFF_MAX)
                return (EIO);
        vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
        return 0;
}

static const int mon_lens[2][12] = {
        {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
        {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
};

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;
}

/*
 * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
 */
static void
udf_timetotimespec(struct timestamp *time, struct timespec *t)
{
        int i, lpyear, daysinyear, year, startyear;
        union {
                uint16_t        u_tz_offset;
                int16_t         s_tz_offset;
        } tz;

        /*
         * DirectCD seems to like using bogus year values.
         * Don't trust time->month as it will be used for an array index.
         */
        year = le16toh(time->year);
        if (year < 1970 || time->month < 1 || time->month > 12) {
                t->tv_sec = 0;
                t->tv_nsec = 0;
                return;
        }

        /* Calculate the time and day */
        t->tv_sec = time->second;
        t->tv_sec += time->minute * 60;
        t->tv_sec += time->hour * 3600;
        t->tv_sec += (time->day - 1) * 3600 * 24;

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

        /* Speed up the calculation */
        startyear = 1970;
        if (year > 2009) {
                t->tv_sec += 1262304000;
                startyear += 40;
        } else if (year > 1999) {
                t->tv_sec += 946684800;
                startyear += 30;
        } else if (year > 1989) {
                t->tv_sec += 631152000;
                startyear += 20;
        } else if (year > 1979) {
                t->tv_sec += 315532800;
                startyear += 10;
        }

        daysinyear = (year - startyear) * 365;
        for (i = startyear; i < year; i++)
                daysinyear += udf_isaleapyear(i);
        t->tv_sec += daysinyear * 3600 * 24;

        /* Calculate microseconds */
        t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
            time->usec;

        /*
         * Calculate the time zone.  The timezone is 12 bit signed 2's
         * complement, so we gotta do some extra magic to handle it right.
         */
        tz.u_tz_offset = le16toh(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 ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
                t->tv_sec -= tz.s_tz_offset * 60;

        return;
}

static int
udf_getattr(struct vop_getattr_args *a)
{
        struct vnode *vp;
        struct udf_node *node;
        struct vattr *vap;
        struct file_entry *fentry;

        vp = a->a_vp;
        vap = a->a_vap;
        node = VTON(vp);
        fentry = node->fentry;

        vap->va_fsid = dev2udev(node->udfmp->im_dev);
        vap->va_fileid = node->hash_id;
        vap->va_mode = udf_permtomode(node);
        vap->va_nlink = le16toh(fentry->link_cnt);
        /*
         * XXX The spec says that -1 is valid for uid/gid and indicates an
         * invalid uid/gid.  How should this be represented?
         */
        vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
        vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
        udf_timetotimespec(&fentry->atime, &vap->va_atime);
        udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
        vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
        vap->va_rdev = NODEV;
        if (vp->v_type & VDIR) {
                /*
                 * 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 = le64toh(fentry->logblks_rec);
                if (vap->va_size == 0)
                        vap->va_size = node->udfmp->bsize;
                else if (vap->va_size > UINT64_MAX / node->udfmp->bsize)
                        vap->va_size = UINT64_MAX;
                else
                        vap->va_size *= node->udfmp->bsize;
        } else {
                vap->va_size = le64toh(fentry->inf_len);
        }
        vap->va_flags = 0;
        vap->va_gen = 1;
        vap->va_blocksize = node->udfmp->bsize;
        vap->va_bytes = le64toh(fentry->inf_len);
        vap->va_type = vp->v_type;
        vap->va_filerev = 0; /* XXX */
        return (0);
}

static int
udf_setattr(struct vop_setattr_args *a)
{
        struct vnode *vp;
        struct vattr *vap;

        vp = a->a_vp;
        vap = a->a_vap;
        if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
            vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
            vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
                return (EROFS);
        if (vap->va_size != (u_quad_t)VNOVAL) {
                switch (vp->v_type) {
                case VDIR:
                        return (EISDIR);
                case VLNK:
                case VREG:
                        return (EROFS);
                case VCHR:
                case VBLK:
                case VSOCK:
                case VFIFO:
                case VNON:
                case VBAD:
                case VMARKER:
                        return (0);
                }
        }
        return (0);
}

/*
 * File specific ioctls.
 */
static int
udf_ioctl(struct vop_ioctl_args *a)
{
        printf("%s called\n", __func__);
        return (ENOTTY);
}

/*
 * I'm not sure that this has much value in a read-only filesystem, but
 * cd9660 has it too.
 */
static int
udf_pathconf(struct vop_pathconf_args *a)
{

        switch (a->a_name) {
        case _PC_FILESIZEBITS:
                *a->a_retval = 64;
                return (0);
        case _PC_LINK_MAX:
                *a->a_retval = 65535;
                return (0);
        case _PC_NAME_MAX:
                *a->a_retval = NAME_MAX;
                return (0);
        case _PC_SYMLINK_MAX:
                *a->a_retval = MAXPATHLEN;
                return (0);
        case _PC_NO_TRUNC:
                *a->a_retval = 1;
                return (0);
        case _PC_PIPE_BUF:
                if (a->a_vp->v_type == VDIR || a->a_vp->v_type == VFIFO) {
                        *a->a_retval = PIPE_BUF;
                        return (0);
                }
                return (EINVAL);
        default:
                return (vop_stdpathconf(a));
        }
}

static int
udf_print(struct vop_print_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct udf_node *node = VTON(vp);

        printf("    ino %lu, on dev %s", (u_long)node->hash_id,
            devtoname(node->udfmp->im_dev));
        if (vp->v_type == VFIFO)
                fifo_printinfo(vp);
        printf("\n");
        return (0);
}

#define lblkno(udfmp, loc)      ((loc) >> (udfmp)->bshift)
#define blkoff(udfmp, loc)      ((loc) & (udfmp)->bmask)
#define lblktosize(udfmp, blk)  ((blk) << (udfmp)->bshift)

static inline int
is_data_in_fentry(const struct udf_node *node)
{
        const struct file_entry *fentry = node->fentry;

        return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
}

static int
udf_read(struct vop_read_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
        struct udf_node *node = VTON(vp);
        struct udf_mnt *udfmp;
        struct file_entry *fentry;
        struct buf *bp;
        uint8_t *data;
        daddr_t lbn, rablock;
        uint64_t len;
        off_t diff, fsize;
        ssize_t n;
        int error = 0;
        long size, on;

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

        if (is_data_in_fentry(node)) {
                fentry = node->fentry;
                data = &fentry->data[le32toh(fentry->l_ea)];
                fsize = le32toh(fentry->l_ad);

                n = uio->uio_resid;
                diff = fsize - uio->uio_offset;
                if (diff <= 0)
                        return (0);
                if (diff < n)
                        n = diff;
                error = uiomove(data + uio->uio_offset, (int)n, uio);
                return (error);
        }

        len = le64toh(node->fentry->inf_len);
        if (len > OFF_MAX) {
                /* too big, just cap to the requested length */
                len = uio->uio_resid;
        }
        fsize = len;
        udfmp = node->udfmp;
        do {
                lbn = lblkno(udfmp, uio->uio_offset);
                on = blkoff(udfmp, uio->uio_offset);
                n = min((u_int)(udfmp->bsize - on),
                        uio->uio_resid);
                diff = fsize - uio->uio_offset;
                if (diff <= 0)
                        return (0);
                if (diff < n)
                        n = diff;
                size = udfmp->bsize;
                rablock = lbn + 1;
                if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
                        if (lblktosize(udfmp, rablock) < fsize) {
                                error = cluster_read(vp, fsize, lbn, size,
                                    NOCRED, uio->uio_resid,
                                    (ap->a_ioflag >> 16), 0, &bp);
                        } else {
                                error = bread(vp, lbn, size, NOCRED, &bp);
                        }
                } else {
                        error = bread(vp, lbn, size, NOCRED, &bp);
                }
                if (error != 0) {
                        brelse(bp);
                        return (error);
                }
                n = min(n, size - bp->b_resid);

                error = uiomove(bp->b_data + on, (int)n, uio);
                brelse(bp);
        } while (error == 0 && uio->uio_resid > 0 && n != 0);
        return (error);
}

/*
 * Call the OSTA routines to 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.
 */
static int
udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
{
        unicode_t *transname;
        char *unibuf, *unip;
        int i, destlen;
        ssize_t unilen = 0;
        size_t destleft = MAXNAMLEN;

        /* Convert 16-bit Unicode to destname */
        if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
                /* allocate a buffer big enough to hold an 8->16 bit expansion */
                unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
                unip = unibuf;
                if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
                        printf("udf: Unicode translation failed\n");
                        uma_zfree(udf_zone_trans, unibuf);
                        return 0;
                }

                while (unilen > 0 && destleft > 0) {
                        udf_iconv->conv(udfmp->im_d2l, __DECONST(const char **,
                            &unibuf), (size_t *)&unilen, (char **)&destname,
                            &destleft);
                        /* Unconverted character found */
                        if (unilen > 0 && destleft > 0) {
                                *destname++ = '?';
                                destleft--;
                                unibuf += 2;
                                unilen -= 2;
                        }
                }
                uma_zfree(udf_zone_trans, unip);
                *destname = '\0';
                destlen = MAXNAMLEN - (int)destleft;
        } else {
                /* allocate a buffer big enough to hold an 8->16 bit expansion */
                transname = uma_zalloc(udf_zone_trans, M_WAITOK);

                if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
                        printf("udf: Unicode translation failed\n");
                        uma_zfree(udf_zone_trans, transname);
                        return 0;
                }

                for (i = 0; i < unilen ; i++) {
                        if (transname[i] & 0xff00) {
                                destname[i] = '.';      /* Fudge the 16bit chars */
                        } else {
                                destname[i] = transname[i] & 0xff;
                        }
                }
                uma_zfree(udf_zone_trans, transname);
                destname[unilen] = 0;
                destlen = (int)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 udf_mnt *udfmp)
{
        char *transname;
        int error = 0;

        /* This is overkill, but not worth creating a new zone */
        transname = uma_zalloc(udf_zone_trans, M_WAITOK);

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

        /* 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);

        uma_zfree(udf_zone_trans, transname);
        return (error);
}

struct udf_uiodir {
        struct dirent *dirent;
        uint64_t *cookies;
        int ncookies;
        int acookies;
        int eofflag;
};

static int
udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
{
        if (uiodir->cookies != NULL) {
                if (++uiodir->acookies > uiodir->ncookies) {
                        uiodir->eofflag = 0;
                        return (-1);
                }
                *uiodir->cookies++ = cookie;
        }

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

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

static struct udf_dirstream *
udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
{
        struct udf_dirstream *ds;

        ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);

        ds->node = node;
        ds->offset = offset;
        ds->udfmp = udfmp;
        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);
                        return (NULL);
                }
        }

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

        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 + le16toh(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->udfmp->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->udfmp->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);

                /* 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;
                        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 + le16toh(fid->l_iu) + fid->l_fi;
                if (total_fid_size > ds->udfmp->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 = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
        }

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

        return (fid);
}

static void
udf_closedir(struct udf_dirstream *ds)
{

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

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

        uma_zfree(udf_zone_ds, ds);
}

static int
udf_readdir(struct vop_readdir_args *a)
{
        struct vnode *vp;
        struct uio *uio;
        struct dirent dir;
        struct udf_node *node;
        struct udf_mnt *udfmp;
        struct fileid_desc *fid;
        struct udf_uiodir uiodir;
        struct udf_dirstream *ds;
        uint64_t *cookies = NULL;
        uint64_t len;
        int ncookies;
        int error = 0;

        vp = a->a_vp;
        uio = a->a_uio;
        node = VTON(vp);
        udfmp = node->udfmp;
        uiodir.eofflag = 1;

        if (a->a_ncookies != NULL) {
                /*
                 * Guess how many entries are needed.  If we run out, this
                 * function will be called again and thing will pick up were
                 * it left off.
                 */
                ncookies = uio->uio_resid / 8;
                cookies = malloc(sizeof(*cookies) * ncookies, M_TEMP, M_WAITOK);
                uiodir.ncookies = ncookies;
                uiodir.cookies = cookies;
                uiodir.acookies = 0;
        } else {
                uiodir.cookies = NULL;
        }

        /*
         * Iterate through the file id descriptors.  Give the parent dir
         * entry special attention.
         */
        len = le64toh(node->fentry->inf_len);
        if (len > INT_MAX) {
                /* too big, just cap to INT_MAX */
                len = INT_MAX;
        }
        ds = udf_opendir(node, uio->uio_offset, len, node->udfmp);

        while ((fid = udf_getfid(ds)) != NULL) {
                /* XXX Should we return an error on a bad fid? */
                if (udf_checktag(&fid->tag, TAGID_FID)) {
                        printf("Invalid FID tag\n");
                        hexdump(fid, UDF_FID_SIZE, NULL, 0);
                        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 cookies since the offset here is
                         * usually zero, and NFS doesn't like that value
                         */
                        dir.d_fileno = node->hash_id;
                        dir.d_type = DT_DIR;
                        dir.d_name[0] = '.';
                        dir.d_namlen = 1;
                        dir.d_reclen = GENERIC_DIRSIZ(&dir);
                        dir.d_off = 1;
                        dirent_terminate(&dir);
                        uiodir.dirent = &dir;
                        error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
                        if (error)
                                break;

                        dir.d_fileno = udf_getid(&fid->icb);
                        dir.d_type = DT_DIR;
                        dir.d_name[0] = '.';
                        dir.d_name[1] = '.';
                        dir.d_namlen = 2;
                        dir.d_reclen = GENERIC_DIRSIZ(&dir);
                        dir.d_off = 2;
                        dirent_terminate(&dir);
                        uiodir.dirent = &dir;
                        error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
                } else {
                        dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
                            &dir.d_name[0], fid->l_fi, udfmp);
                        dir.d_fileno = udf_getid(&fid->icb);
                        dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
                            DT_DIR : DT_UNKNOWN;
                        dir.d_reclen = GENERIC_DIRSIZ(&dir);
                        dir.d_off = ds->this_off;
                        dirent_terminate(&dir);
                        uiodir.dirent = &dir;
                        error = udf_uiodir(&uiodir, dir.d_reclen, uio,
                            ds->this_off);
                }
                if (error)
                        break;
                uio->uio_offset = ds->offset + ds->off;
        }

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

        if (error < 0)
                error = 0;
        if (!error)
                error = ds->error;

        udf_closedir(ds);

        if (a->a_ncookies != NULL) {
                if (error)
                        free(cookies, M_TEMP);
                else {
                        *a->a_ncookies = uiodir.acookies;
                        *a->a_cookies = cookies;
                }
        }

        return (error);
}

static int
udf_readlink(struct vop_readlink_args *ap)
{
        struct path_component *pc, *end;
        struct vnode *vp;
        struct uio uio;
        struct iovec iov[1];
        struct udf_node *node;
        void *buf;
        char *cp;
        uint64_t len;
        int error, root;

        /*
         * A symbolic link in UDF is a list of variable-length path
         * component structures.  We build a pathname in the caller's
         * uio by traversing this list.
         */
        vp = ap->a_vp;
        node = VTON(vp);
        len = le64toh(node->fentry->inf_len);
        if (len > MAXPATHLEN)
                return (EIO);
        buf = malloc(len, M_DEVBUF, M_WAITOK);
        iov[0].iov_len = len;
        iov[0].iov_base = buf;
        uio.uio_iov = iov;
        uio.uio_iovcnt = 1;
        uio.uio_offset = 0;
        uio.uio_resid = iov[0].iov_len;
        uio.uio_segflg = UIO_SYSSPACE;
        uio.uio_rw = UIO_READ;
        uio.uio_td = curthread;
        error = VOP_READ(vp, &uio, 0, ap->a_cred);
        if (error)
                goto error;

        pc = buf;
        end = (void *)((char *)buf + len);
        root = 0;
        while (pc < end) {
                switch (pc->type) {
                case UDF_PATH_ROOT:
                        /* Only allow this at the beginning of a path. */
                        if ((void *)pc != buf) {
                                error = EINVAL;
                                goto error;
                        }
                        cp = "/";
                        len = 1;
                        root = 1;
                        break;
                case UDF_PATH_DOT:
                        cp = ".";
                        len = 1;
                        break;
                case UDF_PATH_DOTDOT:
                        cp = "..";
                        len = 2;
                        break;
                case UDF_PATH_PATH:
                        if (pc->length == 0) {
                                error = EINVAL;
                                goto error;
                        }
                        /*
                         * XXX: We only support CS8 which appears to map
                         * to ASCII directly.
                         */
                        switch (pc->identifier[0]) {
                        case 8:
                                cp = pc->identifier + 1;
                                len = pc->length - 1;
                                break;
                        default:
                                error = EOPNOTSUPP;
                                goto error;
                        }
                        break;
                default:
                        error = EINVAL;
                        goto error;
                }

                /*
                 * If this is not the first component, insert a path
                 * separator.
                 */
                if (pc != buf) {
                        /* If we started with root we already have a "/". */
                        if (root)
                                goto skipslash;
                        root = 0;
                        if (ap->a_uio->uio_resid < 1) {
                                error = ENAMETOOLONG;
                                goto error;
                        }
                        error = uiomove("/", 1, ap->a_uio);
                        if (error)
                                break;
                }
        skipslash:

                /* Append string at 'cp' of length 'len' to our path. */
                if (len > ap->a_uio->uio_resid) {
                        error = ENAMETOOLONG;
                        goto error;
                }
                error = uiomove(cp, len, ap->a_uio);
                if (error)
                        break;

                /* Advance to next component. */
                pc = (void *)((char *)pc + 4 + pc->length);
        }
error:
        free(buf, M_DEVBUF);
        return (error);
}

static int
udf_strategy(struct vop_strategy_args *a)
{
        struct buf *bp;
        struct vnode *vp;
        struct udf_node *node;
        struct bufobj *bo;
        off_t offset;
        uint32_t maxsize;
        daddr_t sector;
        int error;

        bp = a->a_bp;
        vp = a->a_vp;
        node = VTON(vp);

        if (bp->b_blkno == bp->b_lblkno) {
                offset = lblktosize(node->udfmp, bp->b_lblkno);
                error = udf_bmap_internal(node, offset, &sector, &maxsize);
                if (error) {
                        clrbuf(bp);
                        bp->b_blkno = -1;
                        bufdone(bp);
                        return (0);
                }
                /* bmap gives sector numbers, bio works with device blocks */
                bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
        }
        bo = node->udfmp->im_bo;
        bp->b_iooffset = dbtob(bp->b_blkno);
        BO_STRATEGY(bo, bp);
        return (0);
}

static int
udf_bmap(struct vop_bmap_args *a)
{
        struct udf_node *node;
        uint32_t max_size;
        daddr_t lsector;
        int nblk;
        int error;

        node = VTON(a->a_vp);

        if (a->a_bop != NULL)
                *a->a_bop = &node->udfmp->im_devvp->v_bufobj;
        if (a->a_bnp == NULL)
                return (0);
        if (a->a_runb)
                *a->a_runb = 0;

        /*
         * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
         * error that should not be propagated to calling code.
         * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
         * translate block numbers in this case.
         * Incidentally, this return code will make vnode pager to use VOP_READ
         * to get data for mmap-ed pages and udf_read knows how to do the right
         * thing for this kind of files.
         */
        error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
            &lsector, &max_size);
        if (error == UDF_INVALID_BMAP)
                return (EOPNOTSUPP);
        if (error)
                return (error);

        /* Translate logical to physical sector number */
        *a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);

        /*
         * Determine maximum number of readahead blocks following the
         * requested block.
         */
        if (a->a_runp) {
                nblk = (max_size >> node->udfmp->bshift) - 1;
                if (nblk <= 0)
                        *a->a_runp = 0;
                else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
                        *a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
                else
                        *a->a_runp = nblk;
        }

        if (a->a_runb) {
                *a->a_runb = 0;
        }

        return (0);
}

/*
 * The all powerful VOP_LOOKUP().
 */
static int
udf_lookup(struct vop_cachedlookup_args *a)
{
        struct vnode *dvp;
        struct vnode *tdp = NULL;
        struct vnode **vpp = a->a_vpp;
        struct udf_node *node;
        struct udf_mnt *udfmp;
        struct fileid_desc *fid = NULL;
        struct udf_dirstream *ds;
        uint64_t fsize;
        u_long nameiop;
        u_long flags;
        char *nameptr;
        long namelen;
        ino_t id = 0;
        int offset, error = 0;
        int lkflags, ltype, numdirpasses;

        dvp = a->a_dvp;
        node = VTON(dvp);
        udfmp = node->udfmp;
        nameiop = a->a_cnp->cn_nameiop;
        flags = a->a_cnp->cn_flags;
        lkflags = a->a_cnp->cn_lkflags;
        nameptr = a->a_cnp->cn_nameptr;
        namelen = a->a_cnp->cn_namelen;
        fsize = le64toh(node->fentry->inf_len);
        if (fsize > INT_MAX) {
                /* too big, just cap to INT_MAX */
                fsize = INT_MAX;
        }

        /*
         * 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/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
         */
        if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
                offset = 0;
                numdirpasses = 1;
        } else {
                offset = node->diroff;
                numdirpasses = 2;
                nchstats.ncs_2passes++;
        }

lookloop:
        ds = udf_opendir(node, offset, fsize, udfmp);

        while ((fid = udf_getfid(ds)) != NULL) {
                /* XXX Should we return an error on a bad fid? */
                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, udfmp))) {
                                id = udf_getid(&fid->icb);
                                break;
                        }
                }
        }

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

        /* XXX Bail out here? */
        if (error) {
                udf_closedir(ds);
                return (error);
        }

        /* Did we have a match? */
        if (id) {
                /*
                 * Remember where this entry was if it's the final
                 * component.
                 */
                if ((flags & ISLASTCN) && nameiop == LOOKUP)
                        node->diroff = ds->offset + ds->off;
                if (numdirpasses == 2)
                        nchstats.ncs_pass2++;
                udf_closedir(ds);

                if (flags & ISDOTDOT) {
                        error = vn_vget_ino(dvp, id, lkflags, &tdp);
                } else if (node->hash_id == id) {
                        vref(dvp);      /* we want ourself, ie "." */
                        /*
                         * When we lookup "." we still can be asked to lock it
                         * differently.
                         */
                        ltype = lkflags & LK_TYPE_MASK;
                        if (ltype != VOP_ISLOCKED(dvp)) {
                                if (ltype == LK_EXCLUSIVE)
                                        vn_lock(dvp, LK_UPGRADE | LK_RETRY);
                                else /* if (ltype == LK_SHARED) */
                                        vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
                        }
                        tdp = dvp;
                } else
                        error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
                if (!error) {
                        *vpp = tdp;
                        /* Put this entry in the cache */
                        if (flags & MAKEENTRY)
                                cache_enter(dvp, *vpp, a->a_cnp);
                }
        } else {
                /* Name wasn't found on this pass.  Do another pass? */
                if (numdirpasses == 2) {
                        numdirpasses--;
                        offset = 0;
                        udf_closedir(ds);
                        goto lookloop;
                }
                udf_closedir(ds);

                /* Enter name into cache as non-existant */
                if (flags & MAKEENTRY)
                        cache_enter(dvp, *vpp, a->a_cnp);

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

        return (error);
}

static int
udf_reclaim(struct vop_reclaim_args *a)
{
        struct vnode *vp;
        struct udf_node *unode;

        vp = a->a_vp;
        unode = VTON(vp);

        if (unode != NULL) {
                vfs_hash_remove(vp);

                if (unode->fentry != NULL)
                        free(unode->fentry, M_UDFFENTRY);
                uma_zfree(udf_zone_node, unode);
                vp->v_data = NULL;
        }

        return (0);
}

static int
udf_vptofh(struct vop_vptofh_args *a)
{
        struct udf_node *node;
        struct ifid *ifhp;
        _Static_assert(sizeof(struct ifid) <= sizeof(struct fid),
            "struct ifid cannot be larger than struct fid");

        node = VTON(a->a_vp);
        ifhp = (struct ifid *)a->a_fhp;
        ifhp->ifid_len = sizeof(struct ifid);
        ifhp->ifid_ino = node->hash_id;

        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.
 *
 */
static int
udf_readatoffset(struct udf_node *node, int *size, off_t offset,
    struct buf **bp, uint8_t **data)
{
        struct udf_mnt *udfmp = node->udfmp;
        struct vnode *vp = node->i_vnode;
        struct file_entry *fentry;
        struct buf *bp1;
        uint32_t max_size;
        daddr_t sector;
        off_t off;
        int adj_size;
        int error;

        /*
         * This call is made *not* only to detect UDF_INVALID_BMAP case,
         * max_size is used as an ad-hoc read-ahead hint for "normal" case.
         */
        error = udf_bmap_internal(node, 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.
                 */
                fentry = node->fentry;
                *data = &fentry->data[le32toh(fentry->l_ea)];
                *size = le32toh(fentry->l_ad);
                if (offset >= *size)
                        *size = 0;
                else {
                        *data += offset;
                        *size -= offset;
                }
                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;

        /*
         * Because we will read starting at block boundary, we need to adjust
         * how much we need to read so that all promised data is in.
         * Also, we can't promise to read more than MAXBSIZE bytes starting
         * from block boundary, so adjust what we promise too.
         */
        off = blkoff(udfmp, offset);
        *size = min(*size, MAXBSIZE - off);
        adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
        *bp = NULL;
        if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, 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 & udfmp->bmask];
        return (0);
}

/*
 * Translate a file offset into a logical block and then into a physical
 * block.
 * max_size - maximum number of bytes that can be read starting from given
 * offset, rather than beginning of calculated sector number
 */
static int
udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
    uint32_t *max_size)
{
        struct udf_mnt *udfmp;
        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;

        udfmp = node->udfmp;
        fentry = node->fentry;
        tag = &fentry->icbtag;

        switch (le16toh(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 (le16toh(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 > le32toh(fentry->l_ad)) {
                                printf("File offset out of bounds\n");
                                return (EINVAL);
                        }
                        icb = GETICB(short_ad, fentry,
                            le32toh(fentry->l_ea) + ad_offset);
                        icblen = GETICBLEN(short_ad, icb);
                        ad_num++;
                } while(offset >= icblen);

                lsector = (offset  >> udfmp->bshift) +
                    le32toh(((struct short_ad *)(icb))->pos);

                *max_size = icblen - offset;

                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 > le32toh(fentry->l_ad)) {
                                printf("File offset out of bounds\n");
                                return (EINVAL);
                        }
                        icb = GETICB(long_ad, fentry,
                            le32toh(fentry->l_ea) + ad_offset);
                        icblen = GETICBLEN(long_ad, icb);
                        ad_num++;
                } while(offset >= icblen);

                lsector = (offset >> udfmp->bshift) +
                    le32toh(((struct long_ad *)(icb))->loc.lb_num);

                *max_size = icblen - offset;

                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 = node->hash_id + udfmp->part_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 + udfmp->part_start;

        /*
         * Check the sparing table.  Each entry represents the beginning of
         * a packet.
         */
        if (udfmp->s_table != NULL) {
                for (i = 0; i< udfmp->s_table_entries; i++) {
                        p_offset =
                            lsector - le32toh(udfmp->s_table->entries[i].org);
                        if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
                                *sector =
                                   le32toh(udfmp->s_table->entries[i].map) +
                                    p_offset;
                                break;
                        }
                }
        }

        return (0);
}