ldm.c

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#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/stringify.h>
#include <linux/kernel.h>
#include "ldm.h"
#include "check.h"
#include "msdos.h"

#ifndef CONFIG_LDM_DEBUG
#define ldm_debug(...)  do {} while (0)
#else
#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
#endif

#define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
#define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
#define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)

static __printf(3, 4)
void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
{
    struct va_format vaf;
    va_list args;

    va_start (args, fmt);

    vaf.fmt = fmt;
    vaf.va = &args;

    printk("%s%s(): %pV\n", level, function, &vaf);

    va_end(args);
}

static int ldm_parse_hexbyte (const u8 *src)
{
    unsigned int x;     /* For correct wrapping */
    int h;

    /* high part */
    x = h = hex_to_bin(src[0]);
    if (h < 0)
        return -1;

    /* low part */
    h = hex_to_bin(src[1]);
    if (h < 0)
        return -1;

    return (x << 4) + h;
}

static bool ldm_parse_guid (const u8 *src, u8 *dest)
{
    static const int size[] = { 4, 2, 2, 2, 6 };
    int i, j, v;

    if (src[8]  != '-' || src[13] != '-' ||
        src[18] != '-' || src[23] != '-')
        return false;

    for (j = 0; j < 5; j++, src++)
        for (i = 0; i < size[j]; i++, src+=2, *dest++ = v)
            if ((v = ldm_parse_hexbyte (src)) < 0)
                return false;

    return true;
}

static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
{
    bool is_vista = false;

    BUG_ON(!data || !ph);
    if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
        ldm_error("Cannot find PRIVHEAD structure. LDM database is"
            " corrupt. Aborting.");
        return false;
    }
    ph->ver_major = get_unaligned_be16(data + 0x000C);
    ph->ver_minor = get_unaligned_be16(data + 0x000E);
    ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
    ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
    ph->config_start = get_unaligned_be64(data + 0x012B);
    ph->config_size = get_unaligned_be64(data + 0x0133);
    /* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
    if (ph->ver_major == 2 && ph->ver_minor == 12)
        is_vista = true;
    if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
        ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
            " Aborting.", ph->ver_major, ph->ver_minor);
        return false;
    }
    ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
            ph->ver_minor, is_vista ? "Vista" : "2000/XP");
    if (ph->config_size != LDM_DB_SIZE) {   /* 1 MiB in sectors. */
        /* Warn the user and continue, carefully. */
        ldm_info("Database is normally %u bytes, it claims to "
            "be %llu bytes.", LDM_DB_SIZE,
            (unsigned long long)ph->config_size);
    }
    if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
            ph->logical_disk_size > ph->config_start)) {
        ldm_error("PRIVHEAD disk size doesn't match real disk size");
        return false;
    }
    if (!ldm_parse_guid(data + 0x0030, ph->disk_id)) {
        ldm_error("PRIVHEAD contains an invalid GUID.");
        return false;
    }
    ldm_debug("Parsed PRIVHEAD successfully.");
    return true;
}

static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
{
    BUG_ON (!data || !toc);

    if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
        ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
        return false;
    }
    strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
    toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
    toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
    toc->bitmap1_size  = get_unaligned_be64(data + 0x36);

    if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
            sizeof (toc->bitmap1_name)) != 0) {
        ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
                TOC_BITMAP1, toc->bitmap1_name);
        return false;
    }
    strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
    toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
    toc->bitmap2_start = get_unaligned_be64(data + 0x50);
    toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
    if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
            sizeof (toc->bitmap2_name)) != 0) {
        ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
                TOC_BITMAP2, toc->bitmap2_name);
        return false;
    }
    ldm_debug ("Parsed TOCBLOCK successfully.");
    return true;
}

static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
{
    BUG_ON (!data || !vm);

    if (MAGIC_VMDB != get_unaligned_be32(data)) {
        ldm_crit ("Cannot find the VMDB, database may be corrupt.");
        return false;
    }

    vm->ver_major = get_unaligned_be16(data + 0x12);
    vm->ver_minor = get_unaligned_be16(data + 0x14);
    if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
        ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
            "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
        return false;
    }

    vm->vblk_size     = get_unaligned_be32(data + 0x08);
    if (vm->vblk_size == 0) {
        ldm_error ("Illegal VBLK size");
        return false;
    }

    vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
    vm->last_vblk_seq = get_unaligned_be32(data + 0x04);

    ldm_debug ("Parsed VMDB successfully.");
    return true;
}

static bool ldm_compare_privheads (const struct privhead *ph1,
                   const struct privhead *ph2)
{
    BUG_ON (!ph1 || !ph2);

    return ((ph1->ver_major          == ph2->ver_major)     &&
        (ph1->ver_minor          == ph2->ver_minor)     &&
        (ph1->logical_disk_start == ph2->logical_disk_start)    &&
        (ph1->logical_disk_size  == ph2->logical_disk_size) &&
        (ph1->config_start       == ph2->config_start)      &&
        (ph1->config_size        == ph2->config_size)       &&
        !memcmp (ph1->disk_id, ph2->disk_id, GUID_SIZE));
}

static bool ldm_compare_tocblocks (const struct tocblock *toc1,
                   const struct tocblock *toc2)
{
    BUG_ON (!toc1 || !toc2);

    return ((toc1->bitmap1_start == toc2->bitmap1_start)    &&
        (toc1->bitmap1_size  == toc2->bitmap1_size) &&
        (toc1->bitmap2_start == toc2->bitmap2_start)    &&
        (toc1->bitmap2_size  == toc2->bitmap2_size) &&
        !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
            sizeof (toc1->bitmap1_name))        &&
        !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
            sizeof (toc1->bitmap2_name)));
}

static bool ldm_validate_privheads(struct parsed_partitions *state,
                   struct privhead *ph1)
{
    static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
    struct privhead *ph[3] = { ph1 };
    Sector sect;
    u8 *data;
    bool result = false;
    long num_sects;
    int i;

    BUG_ON (!state || !ph1);

    ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
    ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
    if (!ph[1] || !ph[2]) {
        ldm_crit ("Out of memory.");
        goto out;
    }

    /* off[1 & 2] are relative to ph[0]->config_start */
    ph[0]->config_start = 0;

    /* Read and parse privheads */
    for (i = 0; i < 3; i++) {
        data = read_part_sector(state, ph[0]->config_start + off[i],
                    &sect);
        if (!data) {
            ldm_crit ("Disk read failed.");
            goto out;
        }
        result = ldm_parse_privhead (data, ph[i]);
        put_dev_sector (sect);
        if (!result) {
            ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
            if (i < 2)
                goto out;   /* Already logged */
            else
                break;  /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
        }
    }

    num_sects = state->bdev->bd_inode->i_size >> 9;

    if ((ph[0]->config_start > num_sects) ||
       ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
        ldm_crit ("Database extends beyond the end of the disk.");
        goto out;
    }

    if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
       ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
            > ph[0]->config_start)) {
        ldm_crit ("Disk and database overlap.");
        goto out;
    }

    if (!ldm_compare_privheads (ph[0], ph[1])) {
        ldm_crit ("Primary and backup PRIVHEADs don't match.");
        goto out;
    }
    /* FIXME ignore this for now
    if (!ldm_compare_privheads (ph[0], ph[2])) {
        ldm_crit ("Primary and backup PRIVHEADs don't match.");
        goto out;
    }*/
    ldm_debug ("Validated PRIVHEADs successfully.");
    result = true;
out:
    kfree (ph[1]);
    kfree (ph[2]);
    return result;
}

static bool ldm_validate_tocblocks(struct parsed_partitions *state,
                   unsigned long base, struct ldmdb *ldb)
{
    static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
    struct tocblock *tb[4];
    struct privhead *ph;
    Sector sect;
    u8 *data;
    int i, nr_tbs;
    bool result = false;

    BUG_ON(!state || !ldb);
    ph = &ldb->ph;
    tb[0] = &ldb->toc;
    tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
    if (!tb[1]) {
        ldm_crit("Out of memory.");
        goto err;
    }
    tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
    tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
    /*
     * Try to read and parse all four TOCBLOCKs.
     *
     * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
     * skip any that fail as long as we get at least one valid TOCBLOCK.
     */
    for (nr_tbs = i = 0; i < 4; i++) {
        data = read_part_sector(state, base + off[i], &sect);
        if (!data) {
            ldm_error("Disk read failed for TOCBLOCK %d.", i);
            continue;
        }
        if (ldm_parse_tocblock(data, tb[nr_tbs]))
            nr_tbs++;
        put_dev_sector(sect);
    }
    if (!nr_tbs) {
        ldm_crit("Failed to find a valid TOCBLOCK.");
        goto err;
    }
    /* Range check the TOCBLOCK against a privhead. */
    if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
            ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
            ph->config_size)) {
        ldm_crit("The bitmaps are out of range.  Giving up.");
        goto err;
    }
    /* Compare all loaded TOCBLOCKs. */
    for (i = 1; i < nr_tbs; i++) {
        if (!ldm_compare_tocblocks(tb[0], tb[i])) {
            ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
            goto err;
        }
    }
    ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
    result = true;
err:
    kfree(tb[1]);
    return result;
}

static bool ldm_validate_vmdb(struct parsed_partitions *state,
                  unsigned long base, struct ldmdb *ldb)
{
    Sector sect;
    u8 *data;
    bool result = false;
    struct vmdb *vm;
    struct tocblock *toc;

    BUG_ON (!state || !ldb);

    vm  = &ldb->vm;
    toc = &ldb->toc;

    data = read_part_sector(state, base + OFF_VMDB, &sect);
    if (!data) {
        ldm_crit ("Disk read failed.");
        return false;
    }

    if (!ldm_parse_vmdb (data, vm))
        goto out;               /* Already logged */

    /* Are there uncommitted transactions? */
    if (get_unaligned_be16(data + 0x10) != 0x01) {
        ldm_crit ("Database is not in a consistent state.  Aborting.");
        goto out;
    }

    if (vm->vblk_offset != 512)
        ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);

    /*
     * The last_vblkd_seq can be before the end of the vmdb, just make sure
     * it is not out of bounds.
     */
    if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
        ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
                "Database is corrupt.  Aborting.");
        goto out;
    }

    result = true;
out:
    put_dev_sector (sect);
    return result;
}


static bool ldm_validate_partition_table(struct parsed_partitions *state)
{
    Sector sect;
    u8 *data;
    struct partition *p;
    int i;
    bool result = false;

    BUG_ON(!state);

    data = read_part_sector(state, 0, &sect);
    if (!data) {
        ldm_info ("Disk read failed.");
        return false;
    }

    if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
        goto out;

    p = (struct partition*)(data + 0x01BE);
    for (i = 0; i < 4; i++, p++)
        if (SYS_IND (p) == LDM_PARTITION) {
            result = true;
            break;
        }

    if (result)
        ldm_debug ("Found W2K dynamic disk partition type.");

out:
    put_dev_sector (sect);
    return result;
}

static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
{
    struct list_head *item;

    BUG_ON (!ldb);

    list_for_each (item, &ldb->v_disk) {
        struct vblk *v = list_entry (item, struct vblk, list);
        if (!memcmp (v->vblk.disk.disk_id, ldb->ph.disk_id, GUID_SIZE))
            return v;
    }

    return NULL;
}

static bool ldm_create_data_partitions (struct parsed_partitions *pp,
                    const struct ldmdb *ldb)
{
    struct list_head *item;
    struct vblk *vb;
    struct vblk *disk;
    struct vblk_part *part;
    int part_num = 1;

    BUG_ON (!pp || !ldb);

    disk = ldm_get_disk_objid (ldb);
    if (!disk) {
        ldm_crit ("Can't find the ID of this disk in the database.");
        return false;
    }

    strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);

    /* Create the data partitions */
    list_for_each (item, &ldb->v_part) {
        vb = list_entry (item, struct vblk, list);
        part = &vb->vblk.part;

        if (part->disk_id != disk->obj_id)
            continue;

        put_partition (pp, part_num, ldb->ph.logical_disk_start +
                part->start, part->size);
        part_num++;
    }

    strlcat(pp->pp_buf, "\n", PAGE_SIZE);
    return true;
}


static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
{

    base += offset;
    if (!buffer || offset < 0 || base > buflen) {
        if (!buffer)
            ldm_error("!buffer");
        if (offset < 0)
            ldm_error("offset (%d) < 0", offset);
        if (base > buflen)
            ldm_error("base (%d) > buflen (%d)", base, buflen);
        return -1;
    }
    if (base + buffer[base] >= buflen) {
        ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
                buffer[base], buflen);
        return -1;
    }
    return buffer[base] + offset + 1;
}

static u64 ldm_get_vnum (const u8 *block)
{
    u64 tmp = 0;
    u8 length;

    BUG_ON (!block);

    length = *block++;

    if (length && length <= 8)
        while (length--)
            tmp = (tmp << 8) | *block++;
    else
        ldm_error ("Illegal length %d.", length);

    return tmp;
}

static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
{
    int length;

    BUG_ON (!block || !buffer);

    length = block[0];
    if (length >= buflen) {
        ldm_error ("Truncating string %d -> %d.", length, buflen);
        length = buflen - 1;
    }
    memcpy (buffer, block + 1, length);
    buffer[length] = 0;
    return length;
}


static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
    struct vblk_comp *comp;

    BUG_ON (!buffer || !vb);

    r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
    r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
    r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
    r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
    r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);

    if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
        r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
        r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
        len = r_cols;
    } else {
        r_stripe = 0;
        r_cols   = 0;
        len = r_parent;
    }
    if (len < 0)
        return false;

    len += VBLK_SIZE_CMP3;
    if (len != get_unaligned_be32(buffer + 0x14))
        return false;

    comp = &vb->vblk.comp;
    ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
        sizeof (comp->state));
    comp->type      = buffer[0x18 + r_vstate];
    comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
    comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
    comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;

    return true;
}

static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, r_diskid, r_id1, r_id2, len;
    struct vblk_dgrp *dgrp;

    BUG_ON (!buffer || !vb);

    r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
    r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
    r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);

    if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
        r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
        r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
        len = r_id2;
    } else {
        r_id1 = 0;
        r_id2 = 0;
        len = r_diskid;
    }
    if (len < 0)
        return false;

    len += VBLK_SIZE_DGR3;
    if (len != get_unaligned_be32(buffer + 0x14))
        return false;

    dgrp = &vb->vblk.dgrp;
    ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
        sizeof (dgrp->disk_id));
    return true;
}

static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
{
    char buf[64];
    int r_objid, r_name, r_id1, r_id2, len;
    struct vblk_dgrp *dgrp;

    BUG_ON (!buffer || !vb);

    r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
    r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);

    if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
        r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
        r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
        len = r_id2;
    } else {
        r_id1 = 0;
        r_id2 = 0;
        len = r_name;
    }
    if (len < 0)
        return false;

    len += VBLK_SIZE_DGR4;
    if (len != get_unaligned_be32(buffer + 0x14))
        return false;

    dgrp = &vb->vblk.dgrp;

    ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
    return true;
}

static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, r_diskid, r_altname, len;
    struct vblk_disk *disk;

    BUG_ON (!buffer || !vb);

    r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
    r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
    r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
    r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
    len = r_altname;
    if (len < 0)
        return false;

    len += VBLK_SIZE_DSK3;
    if (len != get_unaligned_be32(buffer + 0x14))
        return false;

    disk = &vb->vblk.disk;
    ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
        sizeof (disk->alt_name));
    if (!ldm_parse_guid (buffer + 0x19 + r_name, disk->disk_id))
        return false;

    return true;
}

static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, len;
    struct vblk_disk *disk;

    BUG_ON (!buffer || !vb);

    r_objid = ldm_relative (buffer, buflen, 0x18, 0);
    r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
    len     = r_name;
    if (len < 0)
        return false;

    len += VBLK_SIZE_DSK4;
    if (len != get_unaligned_be32(buffer + 0x14))
        return false;

    disk = &vb->vblk.disk;
    memcpy (disk->disk_id, buffer + 0x18 + r_name, GUID_SIZE);
    return true;
}

static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
    struct vblk_part *part;

    BUG_ON(!buffer || !vb);
    r_objid = ldm_relative(buffer, buflen, 0x18, 0);
    if (r_objid < 0) {
        ldm_error("r_objid %d < 0", r_objid);
        return false;
    }
    r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
    if (r_name < 0) {
        ldm_error("r_name %d < 0", r_name);
        return false;
    }
    r_size = ldm_relative(buffer, buflen, 0x34, r_name);
    if (r_size < 0) {
        ldm_error("r_size %d < 0", r_size);
        return false;
    }
    r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
    if (r_parent < 0) {
        ldm_error("r_parent %d < 0", r_parent);
        return false;
    }
    r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
    if (r_diskid < 0) {
        ldm_error("r_diskid %d < 0", r_diskid);
        return false;
    }
    if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
        r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
        if (r_index < 0) {
            ldm_error("r_index %d < 0", r_index);
            return false;
        }
        len = r_index;
    } else {
        r_index = 0;
        len = r_diskid;
    }
    if (len < 0) {
        ldm_error("len %d < 0", len);
        return false;
    }
    len += VBLK_SIZE_PRT3;
    if (len > get_unaligned_be32(buffer + 0x14)) {
        ldm_error("len %d > BE32(buffer + 0x14) %d", len,
                get_unaligned_be32(buffer + 0x14));
        return false;
    }
    part = &vb->vblk.part;
    part->start = get_unaligned_be64(buffer + 0x24 + r_name);
    part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
    part->size = ldm_get_vnum(buffer + 0x34 + r_name);
    part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
    part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
    if (vb->flags & VBLK_FLAG_PART_INDEX)
        part->partnum = buffer[0x35 + r_diskid];
    else
        part->partnum = 0;
    return true;
}

static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
{
    int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
    int r_id1, r_id2, r_size2, r_drive, len;
    struct vblk_volu *volu;

    BUG_ON(!buffer || !vb);
    r_objid = ldm_relative(buffer, buflen, 0x18, 0);
    if (r_objid < 0) {
        ldm_error("r_objid %d < 0", r_objid);
        return false;
    }
    r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
    if (r_name < 0) {
        ldm_error("r_name %d < 0", r_name);
        return false;
    }
    r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
    if (r_vtype < 0) {
        ldm_error("r_vtype %d < 0", r_vtype);
        return false;
    }
    r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
    if (r_disable_drive_letter < 0) {
        ldm_error("r_disable_drive_letter %d < 0",
                r_disable_drive_letter);
        return false;
    }
    r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
    if (r_child < 0) {
        ldm_error("r_child %d < 0", r_child);
        return false;
    }
    r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
    if (r_size < 0) {
        ldm_error("r_size %d < 0", r_size);
        return false;
    }
    if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
        r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
        if (r_id1 < 0) {
            ldm_error("r_id1 %d < 0", r_id1);
            return false;
        }
    } else
        r_id1 = r_size;
    if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
        r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
        if (r_id2 < 0) {
            ldm_error("r_id2 %d < 0", r_id2);
            return false;
        }
    } else
        r_id2 = r_id1;
    if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
        r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
        if (r_size2 < 0) {
            ldm_error("r_size2 %d < 0", r_size2);
            return false;
        }
    } else
        r_size2 = r_id2;
    if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
        r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
        if (r_drive < 0) {
            ldm_error("r_drive %d < 0", r_drive);
            return false;
        }
    } else
        r_drive = r_size2;
    len = r_drive;
    if (len < 0) {
        ldm_error("len %d < 0", len);
        return false;
    }
    len += VBLK_SIZE_VOL5;
    if (len > get_unaligned_be32(buffer + 0x14)) {
        ldm_error("len %d > BE32(buffer + 0x14) %d", len,
                get_unaligned_be32(buffer + 0x14));
        return false;
    }
    volu = &vb->vblk.volu;
    ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
            sizeof(volu->volume_type));
    memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
            sizeof(volu->volume_state));
    volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
    volu->partition_type = buffer[0x41 + r_size];
    memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
    if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
        ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
                sizeof(volu->drive_hint));
    }
    return true;
}

static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
{
    bool result = false;
    int r_objid;

    BUG_ON (!buf || !vb);

    r_objid = ldm_relative (buf, len, 0x18, 0);
    if (r_objid < 0) {
        ldm_error ("VBLK header is corrupt.");
        return false;
    }

    vb->flags  = buf[0x12];
    vb->type   = buf[0x13];
    vb->obj_id = ldm_get_vnum (buf + 0x18);
    ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));

    switch (vb->type) {
        case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
        case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
        case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
        case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
        case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
        case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
        case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
    }

    if (result)
        ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
             (unsigned long long) vb->obj_id, vb->type);
    else
        ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
            (unsigned long long) vb->obj_id, vb->type);

    return result;
}


static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
{
    struct vblk *vb;
    struct list_head *item;

    BUG_ON (!data || !ldb);

    vb = kmalloc (sizeof (*vb), GFP_KERNEL);
    if (!vb) {
        ldm_crit ("Out of memory.");
        return false;
    }

    if (!ldm_parse_vblk (data, len, vb)) {
        kfree(vb);
        return false;           /* Already logged */
    }

    /* Put vblk into the correct list. */
    switch (vb->type) {
    case VBLK_DGR3:
    case VBLK_DGR4:
        list_add (&vb->list, &ldb->v_dgrp);
        break;
    case VBLK_DSK3:
    case VBLK_DSK4:
        list_add (&vb->list, &ldb->v_disk);
        break;
    case VBLK_VOL5:
        list_add (&vb->list, &ldb->v_volu);
        break;
    case VBLK_CMP3:
        list_add (&vb->list, &ldb->v_comp);
        break;
    case VBLK_PRT3:
        /* Sort by the partition's start sector. */
        list_for_each (item, &ldb->v_part) {
            struct vblk *v = list_entry (item, struct vblk, list);
            if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
                (v->vblk.part.start > vb->vblk.part.start)) {
                list_add_tail (&vb->list, &v->list);
                return true;
            }
        }
        list_add_tail (&vb->list, &ldb->v_part);
        break;
    }
    return true;
}

static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
{
    struct frag *f;
    struct list_head *item;
    int rec, num, group;

    BUG_ON (!data || !frags);

    if (size < 2 * VBLK_SIZE_HEAD) {
        ldm_error("Value of size is to small.");
        return false;
    }

    group = get_unaligned_be32(data + 0x08);
    rec   = get_unaligned_be16(data + 0x0C);
    num   = get_unaligned_be16(data + 0x0E);
    if ((num < 1) || (num > 4)) {
        ldm_error ("A VBLK claims to have %d parts.", num);
        return false;
    }
    if (rec >= num) {
        ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
        return false;
    }

    list_for_each (item, frags) {
        f = list_entry (item, struct frag, list);
        if (f->group == group)
            goto found;
    }

    f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
    if (!f) {
        ldm_crit ("Out of memory.");
        return false;
    }

    f->group = group;
    f->num   = num;
    f->rec   = rec;
    f->map   = 0xFF << num;

    list_add_tail (&f->list, frags);
found:
    if (rec >= f->num) {
        ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
        return false;
    }
    if (f->map & (1 << rec)) {
        ldm_error ("Duplicate VBLK, part %d.", rec);
        f->map &= 0x7F;         /* Mark the group as broken */
        return false;
    }
    f->map |= (1 << rec);
    if (!rec)
        memcpy(f->data, data, VBLK_SIZE_HEAD);
    data += VBLK_SIZE_HEAD;
    size -= VBLK_SIZE_HEAD;
    memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
    return true;
}

static void ldm_frag_free (struct list_head *list)
{
    struct list_head *item, *tmp;

    BUG_ON (!list);

    list_for_each_safe (item, tmp, list)
        kfree (list_entry (item, struct frag, list));
}

static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
{
    struct frag *f;
    struct list_head *item;

    BUG_ON (!frags || !ldb);

    list_for_each (item, frags) {
        f = list_entry (item, struct frag, list);

        if (f->map != 0xFF) {
            ldm_error ("VBLK group %d is incomplete (0x%02x).",
                f->group, f->map);
            return false;
        }

        if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
            return false;       /* Already logged */
    }
    return true;
}

static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
              struct ldmdb *ldb)
{
    int size, perbuf, skip, finish, s, v, recs;
    u8 *data = NULL;
    Sector sect;
    bool result = false;
    LIST_HEAD (frags);

    BUG_ON(!state || !ldb);

    size   = ldb->vm.vblk_size;
    perbuf = 512 / size;
    skip   = ldb->vm.vblk_offset >> 9;      /* Bytes to sectors */
    finish = (size * ldb->vm.last_vblk_seq) >> 9;

    for (s = skip; s < finish; s++) {       /* For each sector */
        data = read_part_sector(state, base + OFF_VMDB + s, &sect);
        if (!data) {
            ldm_crit ("Disk read failed.");
            goto out;
        }

        for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
            if (MAGIC_VBLK != get_unaligned_be32(data)) {
                ldm_error ("Expected to find a VBLK.");
                goto out;
            }

            recs = get_unaligned_be16(data + 0x0E); /* Number of records */
            if (recs == 1) {
                if (!ldm_ldmdb_add (data, size, ldb))
                    goto out;   /* Already logged */
            } else if (recs > 1) {
                if (!ldm_frag_add (data, size, &frags))
                    goto out;   /* Already logged */
            }
            /* else Record is not in use, ignore it. */
        }
        put_dev_sector (sect);
        data = NULL;
    }

    result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
out:
    if (data)
        put_dev_sector (sect);
    ldm_frag_free (&frags);

    return result;
}

static void ldm_free_vblks (struct list_head *lh)
{
    struct list_head *item, *tmp;

    BUG_ON (!lh);

    list_for_each_safe (item, tmp, lh)
        kfree (list_entry (item, struct vblk, list));
}


int ldm_partition(struct parsed_partitions *state)
{
    struct ldmdb  *ldb;
    unsigned long base;
    int result = -1;

    BUG_ON(!state);

    /* Look for signs of a Dynamic Disk */
    if (!ldm_validate_partition_table(state))
        return 0;

    ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
    if (!ldb) {
        ldm_crit ("Out of memory.");
        goto out;
    }

    /* Parse and check privheads. */
    if (!ldm_validate_privheads(state, &ldb->ph))
        goto out;       /* Already logged */

    /* All further references are relative to base (database start). */
    base = ldb->ph.config_start;

    /* Parse and check tocs and vmdb. */
    if (!ldm_validate_tocblocks(state, base, ldb) ||
        !ldm_validate_vmdb(state, base, ldb))
            goto out;       /* Already logged */

    /* Initialize vblk lists in ldmdb struct */
    INIT_LIST_HEAD (&ldb->v_dgrp);
    INIT_LIST_HEAD (&ldb->v_disk);
    INIT_LIST_HEAD (&ldb->v_volu);
    INIT_LIST_HEAD (&ldb->v_comp);
    INIT_LIST_HEAD (&ldb->v_part);

    if (!ldm_get_vblks(state, base, ldb)) {
        ldm_crit ("Failed to read the VBLKs from the database.");
        goto cleanup;
    }

    /* Finally, create the data partition devices. */
    if (ldm_create_data_partitions(state, ldb)) {
        ldm_debug ("Parsed LDM database successfully.");
        result = 1;
    }
    /* else Already logged */

cleanup:
    ldm_free_vblks (&ldb->v_dgrp);
    ldm_free_vblks (&ldb->v_disk);
    ldm_free_vblks (&ldb->v_volu);
    ldm_free_vblks (&ldb->v_comp);
    ldm_free_vblks (&ldb->v_part);
out:
    kfree (ldb);
    return result;
}