extras/volume_id/volume_id/hfs/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 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE 1
  23 #endif
  24
  25 #ifdef HAVE_CONFIG_H
  26 #  include <config.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <errno.h>
  34 #include <ctype.h>
  35 #include <asm/types.h>
  36
  37 #include "../volume_id.h"
  38 #include "../logging.h"
  39 #include "../util.h"
  40 #include "hfs.h"
  41
  42 #define HFS_SUPERBLOCK_OFFSET           0x400
  43 #define HFS_NODE_LEAF                   0xff
  44 #define HFSPLUS_POR_CNID                1
  45 #define HFSPLUS_EXTENT_COUNT            8
  46
  47 int volume_id_probe_hfs_hfsplus(struct volume_id *id, __u64 off)
  48 {
  49         struct hfs_finder_info{
  50                 __u32   boot_folder;
  51                 __u32   start_app;
  52                 __u32   open_folder;
  53                 __u32   os9_folder;
  54                 __u32   reserved;
  55                 __u32   osx_folder;
  56                 __u8    id[8];
  57         } __attribute__((__packed__));
  58
  59         struct hfs_mdb {
  60                 __u8    signature[2];
  61                 __u32   cr_date;
  62                 __u32   ls_Mod;
  63                 __u16   atrb;
  64                 __u16   nm_fls;
  65                 __u16   vbm_st;
  66                 __u16   alloc_ptr;
  67                 __u16   nm_al_blks;
  68                 __u32   al_blk_size;
  69                 __u32   clp_size;
  70                 __u16   al_bl_st;
  71                 __u32   nxt_cnid;
  72                 __u16   free_bks;
  73                 __u8    label_len;
  74                 __u8    label[27];
  75                 __u32   vol_bkup;
  76                 __u16   vol_seq_num;
  77                 __u32   wr_cnt;
  78                 __u32   xt_clump_size;
  79                 __u32   ct_clump_size;
  80                 __u16   num_root_dirs;
  81                 __u32   file_count;
  82                 __u32   dir_count;
  83                 struct hfs_finder_info finder_info;
  84                 __u8    embed_sig[2];
  85                 __u16   embed_startblock;
  86                 __u16   embed_blockcount;
  87         } __attribute__((__packed__)) *hfs;
  88
  89         struct hfsplus_bnode_descriptor {
  90                 __u32   next;
  91                 __u32   prev;
  92                 __u8    type;
  93                 __u8    height;
  94                 __u16   num_recs;
  95                 __u16   reserved;
  96         } __attribute__((__packed__));
  97
  98         struct hfsplus_bheader_record {
  99                 __u16   depth;
 100                 __u32   root;
 101                 __u32   leaf_count;
 102                 __u32   leaf_head;
 103                 __u32   leaf_tail;
 104                 __u16   node_size;
 105         } __attribute__((__packed__));
 106
 107         struct hfsplus_catalog_key {
 108                 __u16   key_len;
 109                 __u32   parent_id;
 110                 __u16   unicode_len;
 111                 __u8    unicode[255 * 2];
 112         } __attribute__((__packed__));
 113
 114         struct hfsplus_extent {
 115                 __u32 start_block;
 116                 __u32 block_count;
 117         } __attribute__((__packed__));
 118
 119         struct hfsplus_fork {
 120                 __u64 total_size;
 121                 __u32 clump_size;
 122                 __u32 total_blocks;
 123                 struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 124         } __attribute__((__packed__));
 125
 126         struct hfsplus_vol_header {
 127                 __u8    signature[2];
 128                 __u16   version;
 129                 __u32   attributes;
 130                 __u32   last_mount_vers;
 131                 __u32   reserved;
 132                 __u32   create_date;
 133                 __u32   modify_date;
 134                 __u32   backup_date;
 135                 __u32   checked_date;
 136                 __u32   file_count;
 137                 __u32   folder_count;
 138                 __u32   blocksize;
 139                 __u32   total_blocks;
 140                 __u32   free_blocks;
 141                 __u32   next_alloc;
 142                 __u32   rsrc_clump_sz;
 143                 __u32   data_clump_sz;
 144                 __u32   next_cnid;
 145                 __u32   write_count;
 146                 __u64   encodings_bmp;
 147                 struct hfs_finder_info finder_info;
 148                 struct hfsplus_fork alloc_file;
 149                 struct hfsplus_fork ext_file;
 150                 struct hfsplus_fork cat_file;
 151                 struct hfsplus_fork attr_file;
 152                 struct hfsplus_fork start_file;
 153         } __attribute__((__packed__)) *hfsplus;
 154
 155         unsigned int blocksize;
 156         unsigned int cat_block;
 157         unsigned int ext_block_start;
 158         unsigned int ext_block_count;
 159         int ext;
 160         unsigned int leaf_node_head;
 161         unsigned int leaf_node_count;
 162         unsigned int leaf_node_size;
 163         unsigned int leaf_block;
 164         __u64 leaf_off;
 165         unsigned int alloc_block_size;
 166         unsigned int alloc_first_block;
 167         unsigned int embed_first_block;
 168         unsigned int record_count;
 169         struct hfsplus_bnode_descriptor *descr;
 170         struct hfsplus_bheader_record *bnode;
 171         struct hfsplus_catalog_key *key;
 172         unsigned int    label_len;
 173         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 174         const __u8 *buf;
 175
 176         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 177         if (buf == NULL)
 178                 return -1;
 179
 180         hfs = (struct hfs_mdb *) buf;
 181         if (memcmp(hfs->signature, "BD", 2) != 0)
 182                 goto checkplus;
 183
 184         /* it may be just a hfs wrapper for hfs+ */
 185         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 186                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 187                 dbg("alloc_block_size 0x%x", alloc_block_size);
 188
 189                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 190                 dbg("alloc_first_block 0x%x", alloc_first_block);
 191
 192                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 193                 dbg("embed_first_block 0x%x", embed_first_block);
 194
 195                 off += (alloc_first_block * 512) +
 196                        (embed_first_block * alloc_block_size);
 197                 dbg("hfs wrapped hfs+ found at offset 0x%llx", off);
 198
 199                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 200                 if (buf == NULL)
 201                         return -1;
 202                 goto checkplus;
 203         }
 204
 205         if (hfs->label_len > 0 && hfs->label_len < 28) {
 206                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 207                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 208         }
 209
 210         volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
 211
 212         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 213         id->type = "hfs";
 214
 215         return 0;
 216
 217 checkplus:
 218         hfsplus = (struct hfsplus_vol_header *) buf;
 219         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 220                 goto hfsplus;
 221         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 222                 goto hfsplus;
 223         return -1;
 224
 225 hfsplus:
 226         volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
 227
 228         blocksize = be32_to_cpu(hfsplus->blocksize);
 229         dbg("blocksize %u", blocksize);
 230
 231         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 232         cat_block = be32_to_cpu(extents[0].start_block);
 233         dbg("catalog start block 0x%x", cat_block);
 234
 235         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 236         if (buf == NULL)
 237                 goto found;
 238
 239         bnode = (struct hfsplus_bheader_record *)
 240                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 241
 242         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 243         dbg("catalog leaf node 0x%x", leaf_node_head);
 244
 245         leaf_node_size = be16_to_cpu(bnode->node_size);
 246         dbg("leaf node size 0x%x", leaf_node_size);
 247
 248         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 249         dbg("leaf node count 0x%x", leaf_node_count);
 250         if (leaf_node_count == 0)
 251                 goto found;
 252
 253         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 254
 255         /* get physical location */
 256         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 257                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 258                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 259                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 260
 261                 if (ext_block_count == 0)
 262                         goto found;
 263
 264                 /* this is our extent */
 265                 if (leaf_block < ext_block_count)
 266                         break;
 267
 268                 leaf_block -= ext_block_count;
 269         }
 270         if (ext == HFSPLUS_EXTENT_COUNT)
 271                 goto found;
 272         dbg("found block in extent %i", ext);
 273
 274         leaf_off = (ext_block_start + leaf_block) * blocksize;
 275
 276         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 277         if (buf == NULL)
 278                 goto found;
 279
 280         descr = (struct hfsplus_bnode_descriptor *) buf;
 281         dbg("descriptor type 0x%x", descr->type);
 282
 283         record_count = be16_to_cpu(descr->num_recs);
 284         dbg("number of records %u", record_count);
 285         if (record_count == 0)
 286                 goto found;
 287
 288         if (descr->type != HFS_NODE_LEAF)
 289                 goto found;
 290
 291         key = (struct hfsplus_catalog_key *)
 292                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 293
 294         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 295         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 296                 goto found;
 297
 298         label_len = be16_to_cpu(key->unicode_len) * 2;
 299         dbg("label unicode16 len %i", label_len);
 300         volume_id_set_label_raw(id, key->unicode, label_len);
 301         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 302
 303 found:
 304         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 305         id->type = "hfsplus";
 306
 307         return 0;
 308 }