source: MondoRescue/branches/2.2.9/mindi-busybox/util-linux/volume_id/hfs.c@ 2725

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "volume_id_internal.h"

struct hfs_finder_info{
    uint32_t    boot_folder;
    uint32_t    start_app;
    uint32_t    open_folder;
    uint32_t    os9_folder;
    uint32_t    reserved;
    uint32_t    osx_folder;
    uint8_t     id[8];
} PACKED;

struct hfs_mdb {
    uint8_t     signature[2];
    uint32_t    cr_date;
    uint32_t    ls_Mod;
    uint16_t    atrb;
    uint16_t    nm_fls;
    uint16_t    vbm_st;
    uint16_t    alloc_ptr;
    uint16_t    nm_al_blks;
    uint32_t    al_blk_size;
    uint32_t    clp_size;
    uint16_t    al_bl_st;
    uint32_t    nxt_cnid;
    uint16_t    free_bks;
    uint8_t     label_len;
    uint8_t     label[27];
    uint32_t    vol_bkup;
    uint16_t    vol_seq_num;
    uint32_t    wr_cnt;
    uint32_t    xt_clump_size;
    uint32_t    ct_clump_size;
    uint16_t    num_root_dirs;
    uint32_t    file_count;
    uint32_t    dir_count;
    struct hfs_finder_info finder_info;
    uint8_t     embed_sig[2];
    uint16_t    embed_startblock;
    uint16_t    embed_blockcount;
} PACKED;

struct hfsplus_bnode_descriptor {
    uint32_t    next;
    uint32_t    prev;
    uint8_t     type;
    uint8_t     height;
    uint16_t    num_recs;
    uint16_t    reserved;
} PACKED;

struct hfsplus_bheader_record {
    uint16_t    depth;
    uint32_t    root;
    uint32_t    leaf_count;
    uint32_t    leaf_head;
    uint32_t    leaf_tail;
    uint16_t    node_size;
} PACKED;

struct hfsplus_catalog_key {
    uint16_t    key_len;
    uint32_t    parent_id;
    uint16_t    unicode_len;
    uint8_t     unicode[255 * 2];
} PACKED;

struct hfsplus_extent {
    uint32_t    start_block;
    uint32_t    block_count;
} PACKED;

#define HFSPLUS_EXTENT_COUNT        8
struct hfsplus_fork {
    uint64_t    total_size;
    uint32_t    clump_size;
    uint32_t    total_blocks;
    struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
} PACKED;

struct hfsplus_vol_header {
    uint8_t     signature[2];
    uint16_t    version;
    uint32_t    attributes;
    uint32_t    last_mount_vers;
    uint32_t    reserved;
    uint32_t    create_date;
    uint32_t    modify_date;
    uint32_t    backup_date;
    uint32_t    checked_date;
    uint32_t    file_count;
    uint32_t    folder_count;
    uint32_t    blocksize;
    uint32_t    total_blocks;
    uint32_t    free_blocks;
    uint32_t    next_alloc;
    uint32_t    rsrc_clump_sz;
    uint32_t    data_clump_sz;
    uint32_t    next_cnid;
    uint32_t    write_count;
    uint64_t    encodings_bmp;
    struct hfs_finder_info finder_info;
    struct hfsplus_fork alloc_file;
    struct hfsplus_fork ext_file;
    struct hfsplus_fork cat_file;
    struct hfsplus_fork attr_file;
    struct hfsplus_fork start_file;
} PACKED;

#define HFS_SUPERBLOCK_OFFSET       0x400
#define HFS_NODE_LEAF           0xff
#define HFSPLUS_POR_CNID        1

int FAST_FUNC volume_id_probe_hfs_hfsplus(struct volume_id *id /*,uint64_t off*/)
{
    uint64_t off = 0;
    unsigned blocksize;
    unsigned cat_block;
    unsigned ext_block_start;
    unsigned ext_block_count;
    int ext;
    unsigned leaf_node_head;
    unsigned leaf_node_count;
    unsigned leaf_node_size;
    unsigned leaf_block;
    uint64_t leaf_off;
    unsigned alloc_block_size;
    unsigned alloc_first_block;
    unsigned embed_first_block;
    unsigned record_count;
    struct hfsplus_vol_header *hfsplus;
    struct hfsplus_bnode_descriptor *descr;
    struct hfsplus_bheader_record *bnode;
    struct hfsplus_catalog_key *key;
    unsigned label_len;
    struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
    struct hfs_mdb *hfs;
    const uint8_t *buf;

    dbg("probing at offset 0x%llx", (unsigned long long) off);

    buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
    if (buf == NULL)
        return -1;

    hfs = (struct hfs_mdb *) buf;
    if (hfs->signature[0] != 'B' || hfs->signature[1] != 'D')
        goto checkplus;

    /* it may be just a hfs wrapper for hfs+ */
    if (hfs->embed_sig[0] == 'H' && hfs->embed_sig[1] == '+') {
        alloc_block_size = be32_to_cpu(hfs->al_blk_size);
        dbg("alloc_block_size 0x%x", alloc_block_size);

        alloc_first_block = be16_to_cpu(hfs->al_bl_st);
        dbg("alloc_first_block 0x%x", alloc_first_block);

        embed_first_block = be16_to_cpu(hfs->embed_startblock);
        dbg("embed_first_block 0x%x", embed_first_block);

        off += (alloc_first_block * 512) +
               (embed_first_block * alloc_block_size);
        dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);

        buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
        if (buf == NULL)
            return -1;
        goto checkplus;
    }

    if (hfs->label_len > 0 && hfs->label_len < 28) {
//      volume_id_set_label_raw(id, hfs->label, hfs->label_len);
        volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
    }

    volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
//  volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
//  id->type = "hfs";

    return 0;

 checkplus:
    hfsplus = (struct hfsplus_vol_header *) buf;
    if (hfs->signature[0] == 'H')
        if (hfs->signature[1] == '+' || hfs->signature[1] == 'X')
            goto hfsplus;
    return -1;

 hfsplus:
    volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);

    blocksize = be32_to_cpu(hfsplus->blocksize);
    dbg("blocksize %u", blocksize);

    memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
    cat_block = be32_to_cpu(extents[0].start_block);
    dbg("catalog start block 0x%x", cat_block);

    buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
    if (buf == NULL)
        goto found;

    bnode = (struct hfsplus_bheader_record *)
        &buf[sizeof(struct hfsplus_bnode_descriptor)];

    leaf_node_head = be32_to_cpu(bnode->leaf_head);
    dbg("catalog leaf node 0x%x", leaf_node_head);

    leaf_node_size = be16_to_cpu(bnode->node_size);
    dbg("leaf node size 0x%x", leaf_node_size);

    leaf_node_count = be32_to_cpu(bnode->leaf_count);
    dbg("leaf node count 0x%x", leaf_node_count);
    if (leaf_node_count == 0)
        goto found;

    leaf_block = (leaf_node_head * leaf_node_size) / blocksize;

    /* get physical location */
    for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
        ext_block_start = be32_to_cpu(extents[ext].start_block);
        ext_block_count = be32_to_cpu(extents[ext].block_count);
        dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);

        if (ext_block_count == 0)
            goto found;

        /* this is our extent */
        if (leaf_block < ext_block_count)
            break;

        leaf_block -= ext_block_count;
    }
    if (ext == HFSPLUS_EXTENT_COUNT)
        goto found;
    dbg("found block in extent %i", ext);

    leaf_off = (ext_block_start + leaf_block) * blocksize;

    buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
    if (buf == NULL)
        goto found;

    descr = (struct hfsplus_bnode_descriptor *) buf;
    dbg("descriptor type 0x%x", descr->type);

    record_count = be16_to_cpu(descr->num_recs);
    dbg("number of records %u", record_count);
    if (record_count == 0)
        goto found;

    if (descr->type != HFS_NODE_LEAF)
        goto found;

    key = (struct hfsplus_catalog_key *)
        &buf[sizeof(struct hfsplus_bnode_descriptor)];

    dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
    if (key->parent_id != cpu_to_be32(HFSPLUS_POR_CNID))
        goto found;

    label_len = be16_to_cpu(key->unicode_len) * 2;
    dbg("label unicode16 len %i", label_len);
//  volume_id_set_label_raw(id, key->unicode, label_len);
    volume_id_set_label_unicode16(id, key->unicode, BE, label_len);

 found:
//  volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
//  id->type = "hfsplus";

    return 0;
}