/*-
 * 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_vfsops.c,v 1.16 2003/11/05 06:56:08 scottl Exp $
 */

/* udf_vfsops.c */
/* Implement the VFS side of things */

/*
 * Ok, here's how it goes.  The UDF specs are pretty clear on how each data
 * structure is made up, but not very clear on how they relate to each other.
 * Here is the skinny... This demostrates a filesystem with one file in the
 * root directory.  Subdirectories are treated just as normal files, but they
 * have File Id Descriptors of their children as their file data.  As for the
 * Anchor Volume Descriptor Pointer, it can exist in two of the following three
 * places: sector 256, sector n (the max sector of the disk), or sector
 * n - 256.  It's a pretty good bet that one will exist at sector 256 though.
 * One caveat is unclosed CD media.  For that, sector 256 cannot be written,
 * so the Anchor Volume Descriptor Pointer can exist at sector 512 until the
 * media is closed.
 *
 *  Sector:
 *     256:
 *       n: Anchor Volume Descriptor Pointer
 * n - 256:     |
 *              |
 *              |-->Main Volume Descriptor Sequence
 *                      |       |
 *                      |       |
 *                      |       |-->Logical Volume Descriptor
 *                      |                         |
 *                      |-->Partition Descriptor  |
 *                              |                 |
 *                              |                 |
 *                              |-->Fileset Descriptor
 *                                      |
 *                                      |
 *                                      |-->Root Dir File Entry
 *                                              |
 *                                              |
 *                                              |-->File data:
 *                                                  File Id Descriptor
 *                                                      |
 *                                                      |
 *                                                      |-->File Entry
 *                                                              |
 *                                                              |
 *                                                              |-->File data
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/nlookup.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/queue.h>
#include <sys/vnode.h>

#include <sys/buf2.h>

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

extern struct vop_ops udf_vnode_vops;

MALLOC_DEFINE(M_UDFNODE, "UDF node", "UDF node structure");
MALLOC_DEFINE(M_UDFMOUNT, "UDF mount", "UDF mount structure");
MALLOC_DEFINE(M_UDFFENTRY, "UDF fentry", "UDF file entry structure");

static int udf_mount(struct mount *, char *, caddr_t, struct ucred *);
static int udf_unmount(struct mount *, int);
static int udf_root(struct mount *, struct vnode **);
static int udf_statfs(struct mount *, struct statfs *, struct ucred *);
static int udf_fhtovp(struct mount *, struct vnode *,
                                struct fid *, struct vnode **);
static int udf_vptofh(struct vnode *, struct fid *);

static int udf_find_partmaps(struct udf_mnt *, struct logvol_desc *);

static struct vfsops udf_vfsops = {
        .vfs_flags =            0,
        .vfs_mount =            udf_mount,
        .vfs_unmount =          udf_unmount,
        .vfs_root =             udf_root,
        .vfs_statfs =           udf_statfs,
        .vfs_vget =             udf_vget,
        .vfs_fhtovp =           udf_fhtovp,
        .vfs_vptofh =           udf_vptofh
};
VFS_SET(udf_vfsops, udf, VFCF_READONLY);

MODULE_VERSION(udf, 1);

static int udf_mountfs(struct vnode *, struct mount *);

static int
udf_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
{
        struct vnode *devvp;    /* vnode of the mount device */
        struct udf_args args;
        struct udf_mnt *imp = NULL;
        size_t size;
        int error;
        struct nlookupdata nd;

        if ((mp->mnt_flag & MNT_RDONLY) == 0)
                return (EROFS);

        /*
         * No root filesystem support.  Probably not a big deal, since the
         * bootloader doesn't understand UDF.
         */
        if (mp->mnt_flag & MNT_ROOTFS)
                return (ENOTSUP);

        if ((error = copyin(data, (caddr_t)&args, sizeof(struct udf_args))))
                return(error);

        if (mp->mnt_flag & MNT_UPDATE) {
                imp = VFSTOUDFFS(mp);
                if (args.fspec == NULL)
                        return(vfs_export(mp, &imp->im_export, &args.export));
        }

        /* Check that the mount device exists */
        devvp = NULL;
        error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
        if (error == 0)
                error = nlookup(&nd);
        if (error == 0)
                error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
        nlookup_done(&nd);
        if (error)
                return (error);

        if (vn_isdisk(devvp, &error) == 0) {
                vrele(devvp);
                return(error);
        }

        /* Check the access rights on the mount device */
        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_EACCESS(devvp, VREAD, cred);
        if (error)
                error = caps_priv_check(cred, SYSCAP_RESTRICTEDROOT);
        if (error) {
                vput(devvp);
                return(error);
        }
        vn_unlock(devvp);

        if ((error = udf_mountfs(devvp, mp))) {
                vrele(devvp);
                return(error);
        }

        imp = VFSTOUDFFS(mp);

        imp->im_flags = args.flags;

        copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
        udf_statfs(mp, &mp->mnt_stat, cred);
        return(0);
}

/*
 * Check the descriptor tag for both the correct id and correct checksum.
 * Return zero if all is good, EINVAL if not.
 */
int
udf_checktag(struct desc_tag *tag, uint16_t id)
{
        uint8_t *itag;
        uint8_t i, cksum = 0;

        itag = (uint8_t *)tag;

        if (tag->id != id)
                return(EINVAL);

        for (i = 0; i < 15; i++)
                cksum = cksum + itag[i];
        cksum = cksum - itag[4];

        if (cksum == tag->cksum)
                return(0);

        return(EINVAL);
}

static int
udf_mountfs(struct vnode *devvp, struct mount *mp)
{
        struct buf *bp = NULL;
        struct anchor_vdp avdp;
        struct udf_mnt *udfmp = NULL;
        struct part_desc *pd;
        struct logvol_desc *lvd;
        struct fileset_desc *fsd;
        struct file_entry *root_fentry;
        cdev_t dev;
        uint32_t sector, size, mvds_start, mvds_end;
        uint32_t fsd_offset = 0;
        uint16_t part_num = 0, fsd_part = 0;
        int error = EINVAL, needclose = 0;
        int logvol_found = 0, part_found = 0, fsd_found = 0;
        int bsize;

        /*
         * Disallow multiple mounts of the same device. Flush the buffer
         * cache for the device.
         */
        if ((error = vfs_mountedon(devvp)))
                return(error);
        if (vcount(devvp) > 0)
                return(EBUSY);
        if ((error = vinvalbuf(devvp, V_SAVE, 0, 0)))
                return(error);

        vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_OPEN(devvp, FREAD, FSCRED, NULL);
        vn_unlock(devvp);
        if (error)
                return(error);
        needclose = 1;
        dev = devvp->v_rdev;

        udfmp = kmalloc(sizeof(*udfmp), M_UDFMOUNT, M_WAITOK | M_ZERO);

        mp->mnt_data = (qaddr_t)udfmp;
        mp->mnt_stat.f_fsid.val[0] = devid_from_dev(dev);
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        mp->mnt_maxsymlinklen = 0;
        mp->mnt_flag |= MNT_LOCAL;
        udfmp->im_mountp = mp;
        udfmp->im_dev = dev;
        udfmp->im_devvp = devvp;

        bsize = 2048;   /* XXX Should probe the media for it's size */

        /* 
         * Get the Anchor Volume Descriptor Pointer from sector 256.
         * XXX Should also check sector n - 256, n, and 512.
         */
        sector = 256;
        if ((error = bread(devvp, (off_t)sector * bsize, bsize, &bp)) != 0)
                goto bail;
        if ((error = udf_checktag((struct desc_tag *)bp->b_data, TAGID_ANCHOR)))
                goto bail;

        bcopy(bp->b_data, &avdp, sizeof(struct anchor_vdp));
        brelse(bp);
        bp = NULL;

        /*
         * Extract the Partition Descriptor and Logical Volume Descriptor
         * from the Volume Descriptor Sequence.
         * XXX Should we care about the partition type right now?
         * XXX What about multiple partitions?
         */
        mvds_start = avdp.main_vds_ex.loc;
        mvds_end = mvds_start + (avdp.main_vds_ex.len - 1) / bsize;
        for (sector = mvds_start; sector < mvds_end; sector++) {
                if ((error = bread(devvp, (off_t)sector * bsize, bsize,
                                   &bp)) != 0) {
                        kprintf("Can't read sector %d of VDS\n", sector);
                        goto bail;
                }
                lvd = (struct logvol_desc *)bp->b_data;
                if (!udf_checktag(&lvd->tag, TAGID_LOGVOL)) {
                        udfmp->bsize = lvd->lb_size;
                        udfmp->bmask = udfmp->bsize - 1;
                        udfmp->bshift = ffs(udfmp->bsize) - 1;
                        fsd_part = lvd->_lvd_use.fsd_loc.loc.part_num;
                        fsd_offset = lvd->_lvd_use.fsd_loc.loc.lb_num;
                        if (udf_find_partmaps(udfmp, lvd))
                                break;
                        logvol_found = 1;
                }
                pd = (struct part_desc *)bp->b_data;
                if (!udf_checktag(&pd->tag, TAGID_PARTITION)) {
                        part_found = 1;
                        part_num = pd->part_num;
                        udfmp->part_len = pd->part_len;
                        udfmp->part_start = pd->start_loc;
                }

                brelse(bp); 
                bp = NULL;
                if ((part_found) && (logvol_found))
                        break;
        }

        if (!part_found || !logvol_found) {
                error = EINVAL;
                goto bail;
        }

        if (fsd_part != part_num) {
                kprintf("FSD does not lie within the partition!\n");
                error = EINVAL;
                goto bail;
        }


        /*
         * Grab the Fileset Descriptor
         * Thanks to Chuck McCrobie <mccrobie@cablespeed.com> for pointing
         * me in the right direction here.
         */
        sector = udfmp->part_start + fsd_offset;
        if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
                kprintf("Cannot read sector %d of FSD\n", sector);
                goto bail;
        }
        fsd = (struct fileset_desc *)bp->b_data;
        if (!udf_checktag(&fsd->tag, TAGID_FSD)) {
                fsd_found = 1;
                bcopy(&fsd->rootdir_icb, &udfmp->root_icb,
                      sizeof(struct long_ad));
        }

        brelse(bp);
        bp = NULL;

        if (!fsd_found) {
                kprintf("Couldn't find the fsd\n");
                error = EINVAL;
                goto bail;
        } 

        vfs_add_vnodeops(mp, &udf_vnode_vops, &mp->mnt_vn_norm_ops);

        /*
         * Find the file entry for the root directory.
         */
        sector = udfmp->root_icb.loc.lb_num + udfmp->part_start;
        size = udfmp->root_icb.len;
        if ((error = udf_readlblks(udfmp, sector, size, &bp)) != 0) {
                kprintf("Cannot read sector %d\n", sector);
                goto bail;
        }

        root_fentry = (struct file_entry *)bp->b_data;
        if ((error = udf_checktag(&root_fentry->tag, TAGID_FENTRY))) {
                kprintf("Invalid root file entry!\n");
                goto bail;
        }

        brelse(bp);
        bp = NULL;

        lwkt_token_init(&udfmp->hash_token, "udfihash");
        udfmp->hashtbl = phashinit(UDF_HASHTBLSIZE, M_UDFMOUNT, &udfmp->hashsz);

        return(0);

bail:
        if (udfmp != NULL)
                kfree(udfmp, M_UDFMOUNT);
        if (bp != NULL)
                brelse(bp);
        if (needclose) {
                vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
                VOP_CLOSE(devvp, FREAD, NULL);
                vn_unlock(devvp);
        }
        return(error);
}

static int
udf_unmount(struct mount *mp, int mntflags)
{
        struct udf_mnt *udfmp;
        int error, flags = 0;

        udfmp = VFSTOUDFFS(mp);

        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;

        if ((error = vflush(mp, 0, flags)))
                return (error);

        udfmp->im_devvp->v_rdev->si_mountpoint = NULL;
        vn_lock(udfmp->im_devvp, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_CLOSE(udfmp->im_devvp, FREAD, NULL);
        vn_unlock(udfmp->im_devvp);
        vrele(udfmp->im_devvp);

        if (udfmp->s_table)
                kfree(udfmp->s_table, M_UDFMOUNT);
        if (udfmp->hashtbl)
                kfree(udfmp->hashtbl, M_UDFMOUNT);
        kfree(udfmp, M_UDFMOUNT);

        mp->mnt_data = (qaddr_t)0;
        mp->mnt_flag &= ~MNT_LOCAL;

        return (error);
}

static int
udf_root(struct mount *mp, struct vnode **vpp)
{
        struct udf_mnt *udfmp;
        struct vnode *vp;
        ino_t id;
        int error;

        udfmp = VFSTOUDFFS(mp);

        id = udf_getid(&udfmp->root_icb);

        error = udf_vget(mp, NULL, id, vpp);
        if (error)
                return(error);

        vp = *vpp;
        vsetflags(vp, VROOT);
        udfmp->root_vp = vp;

        return(0);
}

static int
udf_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
{
        struct udf_mnt *udfmp;

        udfmp = VFSTOUDFFS(mp);

        sbp->f_bsize = udfmp->bsize;
        sbp->f_iosize = udfmp->bsize;
        sbp->f_blocks = udfmp->part_len;
        sbp->f_bfree = 0;
        sbp->f_bavail = 0;
        sbp->f_files = 0;
        sbp->f_ffree = 0;
        if (sbp != &mp->mnt_stat) {
                sbp->f_type = mp->mnt_vfc->vfc_typenum;
                bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
        }

        return(0);
}

int
udf_vget(struct mount *mp, struct vnode *dvp, ino_t ino, struct vnode **vpp)
{
        struct buf *bp;
        struct vnode *devvp;
        struct udf_mnt *udfmp;
        struct vnode *vp;
        struct udf_node *unode;
        struct file_entry *fe;
        int error, sector, size;

        udfmp = VFSTOUDFFS(mp);

        /* See if we already have this in the cache */
        if ((error = udf_hashlookup(udfmp, ino, vpp)) != 0)
                return(error);
        if (*vpp != NULL) {
                return(0);
        }

        /*
         * Allocate memory and check the tag id's before grabbing a new
         * vnode, since it's hard to roll back if there is a problem.
         */
        unode = kmalloc(sizeof(*unode), M_UDFNODE, M_WAITOK | M_ZERO);

        /*
         * Copy in the file entry.  Per the spec, the size can only be 1 block.
         */
        sector = ino + udfmp->part_start;
        devvp = udfmp->im_devvp;
        if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
                kprintf("Cannot read sector %d\n", sector);
                kfree(unode, M_UDFNODE);
                return(error);
        }

        fe = (struct file_entry *)bp->b_data;
        if (udf_checktag(&fe->tag, TAGID_FENTRY)) {
                kprintf("Invalid file entry!\n");
                kfree(unode, M_UDFNODE);
                brelse(bp);
                return(ENOMEM);
        }
        size = UDF_FENTRY_SIZE + fe->l_ea + fe->l_ad;
        unode->fentry = kmalloc(size, M_UDFFENTRY, M_WAITOK | M_ZERO);

        bcopy(bp->b_data, unode->fentry, size);
        
        brelse(bp);
        bp = NULL;

        if ((error = udf_allocv(mp, &vp))) {
                kprintf("Error from udf_allocv\n");
                kfree(unode, M_UDFNODE);
                return(error);
        }

        unode->i_vnode = vp;
        unode->hash_id = ino;
        unode->i_devvp = udfmp->im_devvp;
        unode->i_dev = udfmp->im_dev;
        unode->udfmp = udfmp;
        vp->v_data = unode;
        vref(udfmp->im_devvp);
        udf_hashins(unode);

        switch (unode->fentry->icbtag.file_type) {
        default:
                vp->v_type = VBAD;
                break;
        case 4:
                vp->v_type = VDIR;
                break;
        case 5:
                vp->v_type = VREG;
                break;
        case 6:
                vp->v_type = VBLK;
                break;
        case 7:
                vp->v_type = VCHR;
                break;
        case 9:
                vp->v_type = VFIFO;
                break;
        case 10:
                vp->v_type = VSOCK;
                break;
        case 12:
                vp->v_type = VLNK;
                break;
        }
        /*
         * Locked and refd vnode returned
         */
        *vpp = vp;

        return(0);
}

struct ifid {
        u_short ifid_len;
        u_short ifid_pad;
        int     ifid_ino;
        long    ifid_start;
};

static int
udf_fhtovp(struct mount *mp, struct vnode *rootvp,
           struct fid *fhp, struct vnode **vpp)
{
        struct ifid *ifhp;
        struct vnode *nvp;
        int error;

        ifhp = (struct ifid *)fhp;

        if ((error = VFS_VGET(mp, NULL, ifhp->ifid_ino, &nvp)) != 0) {
                *vpp = NULLVP;
                return(error);
        }

        *vpp = nvp;
        return(0);
}

static int
udf_vptofh (struct vnode *vp, struct fid *fhp)
{
        struct udf_node *node;
        struct ifid *ifhp;

        node = VTON(vp);
        ifhp = (struct ifid *)fhp;
        ifhp->ifid_len = sizeof(struct ifid);
        ifhp->ifid_ino = node->hash_id;

        return(0);
}

static int
udf_find_partmaps(struct udf_mnt *udfmp, struct logvol_desc *lvd)
{
        union udf_pmap *pmap;
        struct part_map_spare *pms;
        struct regid *pmap_id;
        struct buf *bp;
        unsigned char regid_id[UDF_REGID_ID_SIZE + 1];
        int ptype, psize, error;
        unsigned int i;

        for (i = 0; i < lvd->n_pm; i++) {
                pmap = (union udf_pmap *)&lvd->maps[i * UDF_PMAP_SIZE];
                ptype = pmap->data[0];
                psize = pmap->data[1];
                if (((ptype != 1) && (ptype != 2)) ||
                    ((psize != UDF_PMAP_SIZE) && (psize != 6))) {
                        kprintf("Invalid partition map found\n");
                        return(1);
                }

                if (ptype == 1) {
                        /* Type 1 map.  We don't care */
                        continue;
                }

                /* Type 2 map.  Gotta find out the details */
                pmap_id = (struct regid *)&pmap->data[4];
                bzero(&regid_id[0], UDF_REGID_ID_SIZE);
                bcopy(&pmap_id->id[0], &regid_id[0], UDF_REGID_ID_SIZE);

                if (bcmp(&regid_id[0], "*UDF Sparable Partition",
                    UDF_REGID_ID_SIZE)) {
                        kprintf("Unsupported partition map: %s\n", &regid_id[0]);
                        return(1);
                }

                pms = &pmap->pms;
                udfmp->s_table = kmalloc(pms->st_size, M_UDFMOUNT,
                                        M_WAITOK | M_ZERO);

                /* Calculate the number of sectors per packet. */
                /* XXX Logical or physical? */
                udfmp->p_sectors = pms->packet_len / udfmp->bsize;

                /*
                 * XXX If reading the first Sparing Table fails, should look
                 * for another table.
                 */
                if ((error = udf_readlblks(udfmp, pms->st_loc[0], pms->st_size,
                    &bp)) != 0) {
                        if (bp)
                                brelse(bp);
                        kprintf("Failed to read Sparing Table at sector %d\n",
                            pms->st_loc[0]);
                        return(error);
                }
                bcopy(bp->b_data, udfmp->s_table, pms->st_size);
                brelse(bp);

                if (udf_checktag(&udfmp->s_table->tag, 0)) {
                        kprintf("Invalid sparing table found\n");
                        return(EINVAL);
                }

                /* See how many valid entries there are here.  The list is
                 * supposed to be sorted. 0xfffffff0 and higher are not valid
                 */
                for (i = 0; i < udfmp->s_table->rt_l; i++) {
                        udfmp->s_table_entries = i;
                        if (udfmp->s_table->entries[i].org >= 0xfffffff0)
                                break;
                }
        }

        return(0);
}