util-linux/volume_id/hfs.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation; either
   9  *      version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *      This library is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *      Lesser General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU Lesser General Public
  17  *      License along with this library; if not, write to the Free Software
  18  *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include "volume_id_internal.h"
  22
  23 struct hfs_finder_info{
  24         uint32_t        boot_folder;
  25         uint32_t        start_app;
  26         uint32_t        open_folder;
  27         uint32_t        os9_folder;
  28         uint32_t        reserved;
  29         uint32_t        osx_folder;
  30         uint8_t         id[8];
  31 } PACKED;
  32
  33 struct hfs_mdb {
  34         uint8_t         signature[2];
  35         uint32_t        cr_date;
  36         uint32_t        ls_Mod;
  37         uint16_t        atrb;
  38         uint16_t        nm_fls;
  39         uint16_t        vbm_st;
  40         uint16_t        alloc_ptr;
  41         uint16_t        nm_al_blks;
  42         uint32_t        al_blk_size;
  43         uint32_t        clp_size;
  44         uint16_t        al_bl_st;
  45         uint32_t        nxt_cnid;
  46         uint16_t        free_bks;
  47         uint8_t         label_len;
  48         uint8_t         label[27];
  49         uint32_t        vol_bkup;
  50         uint16_t        vol_seq_num;
  51         uint32_t        wr_cnt;
  52         uint32_t        xt_clump_size;
  53         uint32_t        ct_clump_size;
  54         uint16_t        num_root_dirs;
  55         uint32_t        file_count;
  56         uint32_t        dir_count;
  57         struct hfs_finder_info finder_info;
  58         uint8_t         embed_sig[2];
  59         uint16_t        embed_startblock;
  60         uint16_t        embed_blockcount;
  61 } PACKED;
  62
  63 struct hfsplus_bnode_descriptor {
  64         uint32_t        next;
  65         uint32_t        prev;
  66         uint8_t         type;
  67         uint8_t         height;
  68         uint16_t        num_recs;
  69         uint16_t        reserved;
  70 } PACKED;
  71
  72 struct hfsplus_bheader_record {
  73         uint16_t        depth;
  74         uint32_t        root;
  75         uint32_t        leaf_count;
  76         uint32_t        leaf_head;
  77         uint32_t        leaf_tail;
  78         uint16_t        node_size;
  79 } PACKED;
  80
  81 struct hfsplus_catalog_key {
  82         uint16_t        key_len;
  83         uint32_t        parent_id;
  84         uint16_t        unicode_len;
  85         uint8_t         unicode[255 * 2];
  86 } PACKED;
  87
  88 struct hfsplus_extent {
  89         uint32_t        start_block;
  90         uint32_t        block_count;
  91 } PACKED;
  92
  93 #define HFSPLUS_EXTENT_COUNT            8
  94 struct hfsplus_fork {
  95         uint64_t        total_size;
  96         uint32_t        clump_size;
  97         uint32_t        total_blocks;
  98         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
  99 } PACKED;
 100
 101 struct hfsplus_vol_header {
 102         uint8_t         signature[2];
 103         uint16_t        version;
 104         uint32_t        attributes;
 105         uint32_t        last_mount_vers;
 106         uint32_t        reserved;
 107         uint32_t        create_date;
 108         uint32_t        modify_date;
 109         uint32_t        backup_date;
 110         uint32_t        checked_date;
 111         uint32_t        file_count;
 112         uint32_t        folder_count;
 113         uint32_t        blocksize;
 114         uint32_t        total_blocks;
 115         uint32_t        free_blocks;
 116         uint32_t        next_alloc;
 117         uint32_t        rsrc_clump_sz;
 118         uint32_t        data_clump_sz;
 119         uint32_t        next_cnid;
 120         uint32_t        write_count;
 121         uint64_t        encodings_bmp;
 122         struct hfs_finder_info finder_info;
 123         struct hfsplus_fork alloc_file;
 124         struct hfsplus_fork ext_file;
 125         struct hfsplus_fork cat_file;
 126         struct hfsplus_fork attr_file;
 127         struct hfsplus_fork start_file;
 128 } PACKED;
 129
 130 #define HFS_SUPERBLOCK_OFFSET           0x400
 131 #define HFS_NODE_LEAF                   0xff
 132 #define HFSPLUS_POR_CNID                1
 133
 134 int FAST_FUNC volume_id_probe_hfs_hfsplus(struct volume_id *id /*,uint64_t off*/)
 135 {
 136         uint64_t off = 0;
 137         unsigned blocksize;
 138         unsigned cat_block;
 139         unsigned ext_block_start;
 140         unsigned ext_block_count;
 141         int ext;
 142         unsigned leaf_node_head;
 143         unsigned leaf_node_count;
 144         unsigned leaf_node_size;
 145         unsigned leaf_block;
 146         uint64_t leaf_off;
 147         unsigned alloc_block_size;
 148         unsigned alloc_first_block;
 149         unsigned embed_first_block;
 150         unsigned record_count;
 151         struct hfsplus_vol_header *hfsplus;
 152         struct hfsplus_bnode_descriptor *descr;
 153         struct hfsplus_bheader_record *bnode;
 154         struct hfsplus_catalog_key *key;
 155         unsigned label_len;
 156         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 157         struct hfs_mdb *hfs;
 158         const uint8_t *buf;
 159
 160         dbg("probing at offset 0x%llx", (unsigned long long) off);
 161
 162         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 163         if (buf == NULL)
 164                 return -1;
 165
 166         hfs = (struct hfs_mdb *) buf;
 167         if (hfs->signature[0] != 'B' || hfs->signature[1] != 'D')
 168                 goto checkplus;
 169
 170         /* it may be just a hfs wrapper for hfs+ */
 171         if (hfs->embed_sig[0] == 'H' && hfs->embed_sig[1] == '+') {
 172                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 173                 dbg("alloc_block_size 0x%x", alloc_block_size);
 174
 175                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 176                 dbg("alloc_first_block 0x%x", alloc_first_block);
 177
 178                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 179                 dbg("embed_first_block 0x%x", embed_first_block);
 180
 181                 off += (alloc_first_block * 512) +
 182                        (embed_first_block * alloc_block_size);
 183                 dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);
 184
 185                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 186                 if (buf == NULL)
 187                         return -1;
 188                 goto checkplus;
 189         }
 190
 191         if (hfs->label_len > 0 && hfs->label_len < 28) {
 192 //              volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 193                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 194         }
 195
 196         volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
 197 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 198 //      id->type = "hfs";
 199
 200         return 0;
 201
 202  checkplus:
 203         hfsplus = (struct hfsplus_vol_header *) buf;
 204         if (hfs->signature[0] == 'H')
 205                 if (hfs->signature[1] == '+' || hfs->signature[1] == 'X')
 206                         goto hfsplus;
 207         return -1;
 208
 209  hfsplus:
 210         volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
 211
 212         blocksize = be32_to_cpu(hfsplus->blocksize);
 213         dbg("blocksize %u", blocksize);
 214
 215         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 216         cat_block = be32_to_cpu(extents[0].start_block);
 217         dbg("catalog start block 0x%x", cat_block);
 218
 219         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 220         if (buf == NULL)
 221                 goto found;
 222
 223         bnode = (struct hfsplus_bheader_record *)
 224                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 225
 226         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 227         dbg("catalog leaf node 0x%x", leaf_node_head);
 228
 229         leaf_node_size = be16_to_cpu(bnode->node_size);
 230         dbg("leaf node size 0x%x", leaf_node_size);
 231
 232         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 233         dbg("leaf node count 0x%x", leaf_node_count);
 234         if (leaf_node_count == 0)
 235                 goto found;
 236
 237         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 238
 239         /* get physical location */
 240         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 241                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 242                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 243                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 244
 245                 if (ext_block_count == 0)
 246                         goto found;
 247
 248                 /* this is our extent */
 249                 if (leaf_block < ext_block_count)
 250                         break;
 251
 252                 leaf_block -= ext_block_count;
 253         }
 254         if (ext == HFSPLUS_EXTENT_COUNT)
 255                 goto found;
 256         dbg("found block in extent %i", ext);
 257
 258         leaf_off = (ext_block_start + leaf_block) * blocksize;
 259
 260         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 261         if (buf == NULL)
 262                 goto found;
 263
 264         descr = (struct hfsplus_bnode_descriptor *) buf;
 265         dbg("descriptor type 0x%x", descr->type);
 266
 267         record_count = be16_to_cpu(descr->num_recs);
 268         dbg("number of records %u", record_count);
 269         if (record_count == 0)
 270                 goto found;
 271
 272         if (descr->type != HFS_NODE_LEAF)
 273                 goto found;
 274
 275         key = (struct hfsplus_catalog_key *)
 276                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 277
 278         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 279         if (key->parent_id != cpu_to_be32(HFSPLUS_POR_CNID))
 280                 goto found;
 281
 282         label_len = be16_to_cpu(key->unicode_len) * 2;
 283         dbg("label unicode16 len %i", label_len);
 284 //      volume_id_set_label_raw(id, key->unicode, label_len);
 285         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 286
 287  found:
 288 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 289 //      id->type = "hfsplus";
 290
 291         return 0;
 292 }