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 struct hfs_finder_info{
  43         __u32   boot_folder;
  44         __u32   start_app;
  45         __u32   open_folder;
  46         __u32   os9_folder;
  47         __u32   reserved;
  48         __u32   osx_folder;
  49         __u8    id[8];
  50 } __attribute__((__packed__));
  51
  52 struct hfs_mdb {
  53         __u8    signature[2];
  54         __u32   cr_date;
  55         __u32   ls_Mod;
  56         __u16   atrb;
  57         __u16   nm_fls;
  58         __u16   vbm_st;
  59         __u16   alloc_ptr;
  60         __u16   nm_al_blks;
  61         __u32   al_blk_size;
  62         __u32   clp_size;
  63         __u16   al_bl_st;
  64         __u32   nxt_cnid;
  65         __u16   free_bks;
  66         __u8    label_len;
  67         __u8    label[27];
  68         __u32   vol_bkup;
  69         __u16   vol_seq_num;
  70         __u32   wr_cnt;
  71         __u32   xt_clump_size;
  72         __u32   ct_clump_size;
  73         __u16   num_root_dirs;
  74         __u32   file_count;
  75         __u32   dir_count;
  76         struct hfs_finder_info finder_info;
  77         __u8    embed_sig[2];
  78         __u16   embed_startblock;
  79         __u16   embed_blockcount;
  80 } __attribute__((__packed__)) *hfs;
  81
  82 struct hfsplus_bnode_descriptor {
  83         __u32   next;
  84         __u32   prev;
  85         __u8    type;
  86         __u8    height;
  87         __u16   num_recs;
  88         __u16   reserved;
  89 } __attribute__((__packed__));
  90
  91 struct hfsplus_bheader_record {
  92         __u16   depth;
  93         __u32   root;
  94         __u32   leaf_count;
  95         __u32   leaf_head;
  96         __u32   leaf_tail;
  97         __u16   node_size;
  98 } __attribute__((__packed__));
  99
 100 struct hfsplus_catalog_key {
 101         __u16   key_len;
 102         __u32   parent_id;
 103         __u16   unicode_len;
 104         __u8    unicode[255 * 2];
 105 } __attribute__((__packed__));
 106
 107 struct hfsplus_extent {
 108         __u32 start_block;
 109         __u32 block_count;
 110 } __attribute__((__packed__));
 111
 112 #define HFSPLUS_EXTENT_COUNT            8
 113 struct hfsplus_fork {
 114         __u64 total_size;
 115         __u32 clump_size;
 116         __u32 total_blocks;
 117         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 118 } __attribute__((__packed__));
 119
 120 struct hfsplus_vol_header {
 121         __u8    signature[2];
 122         __u16   version;
 123         __u32   attributes;
 124         __u32   last_mount_vers;
 125         __u32   reserved;
 126         __u32   create_date;
 127         __u32   modify_date;
 128         __u32   backup_date;
 129         __u32   checked_date;
 130         __u32   file_count;
 131         __u32   folder_count;
 132         __u32   blocksize;
 133         __u32   total_blocks;
 134         __u32   free_blocks;
 135         __u32   next_alloc;
 136         __u32   rsrc_clump_sz;
 137         __u32   data_clump_sz;
 138         __u32   next_cnid;
 139         __u32   write_count;
 140         __u64   encodings_bmp;
 141         struct hfs_finder_info finder_info;
 142         struct hfsplus_fork alloc_file;
 143         struct hfsplus_fork ext_file;
 144         struct hfsplus_fork cat_file;
 145         struct hfsplus_fork attr_file;
 146         struct hfsplus_fork start_file;
 147 } __attribute__((__packed__)) *hfsplus;
 148
 149 #define HFS_SUPERBLOCK_OFFSET           0x400
 150 #define HFS_NODE_LEAF                   0xff
 151 #define HFSPLUS_POR_CNID                1
 152
 153 int volume_id_probe_hfs_hfsplus(struct volume_id *id, __u64 off)
 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         dbg("probing at offset %llu", off);
 177
 178         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 179         if (buf == NULL)
 180                 return -1;
 181
 182         hfs = (struct hfs_mdb *) buf;
 183         if (memcmp(hfs->signature, "BD", 2) != 0)
 184                 goto checkplus;
 185
 186         /* it may be just a hfs wrapper for hfs+ */
 187         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 188                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 189                 dbg("alloc_block_size 0x%x", alloc_block_size);
 190
 191                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 192                 dbg("alloc_first_block 0x%x", alloc_first_block);
 193
 194                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 195                 dbg("embed_first_block 0x%x", embed_first_block);
 196
 197                 off += (alloc_first_block * 512) +
 198                        (embed_first_block * alloc_block_size);
 199                 dbg("hfs wrapped hfs+ found at offset 0x%llx", off);
 200
 201                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 202                 if (buf == NULL)
 203                         return -1;
 204                 goto checkplus;
 205         }
 206
 207         if (hfs->label_len > 0 && hfs->label_len < 28) {
 208                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 209                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 210         }
 211
 212         volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
 213
 214         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 215         id->type = "hfs";
 216
 217         return 0;
 218
 219 checkplus:
 220         hfsplus = (struct hfsplus_vol_header *) buf;
 221         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 222                 goto hfsplus;
 223         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 224                 goto hfsplus;
 225         return -1;
 226
 227 hfsplus:
 228         volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
 229
 230         blocksize = be32_to_cpu(hfsplus->blocksize);
 231         dbg("blocksize %u", blocksize);
 232
 233         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 234         cat_block = be32_to_cpu(extents[0].start_block);
 235         dbg("catalog start block 0x%x", cat_block);
 236
 237         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 238         if (buf == NULL)
 239                 goto found;
 240
 241         bnode = (struct hfsplus_bheader_record *)
 242                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 243
 244         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 245         dbg("catalog leaf node 0x%x", leaf_node_head);
 246
 247         leaf_node_size = be16_to_cpu(bnode->node_size);
 248         dbg("leaf node size 0x%x", leaf_node_size);
 249
 250         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 251         dbg("leaf node count 0x%x", leaf_node_count);
 252         if (leaf_node_count == 0)
 253                 goto found;
 254
 255         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 256
 257         /* get physical location */
 258         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 259                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 260                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 261                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 262
 263                 if (ext_block_count == 0)
 264                         goto found;
 265
 266                 /* this is our extent */
 267                 if (leaf_block < ext_block_count)
 268                         break;
 269
 270                 leaf_block -= ext_block_count;
 271         }
 272         if (ext == HFSPLUS_EXTENT_COUNT)
 273                 goto found;
 274         dbg("found block in extent %i", ext);
 275
 276         leaf_off = (ext_block_start + leaf_block) * blocksize;
 277
 278         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 279         if (buf == NULL)
 280                 goto found;
 281
 282         descr = (struct hfsplus_bnode_descriptor *) buf;
 283         dbg("descriptor type 0x%x", descr->type);
 284
 285         record_count = be16_to_cpu(descr->num_recs);
 286         dbg("number of records %u", record_count);
 287         if (record_count == 0)
 288                 goto found;
 289
 290         if (descr->type != HFS_NODE_LEAF)
 291                 goto found;
 292
 293         key = (struct hfsplus_catalog_key *)
 294                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 295
 296         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 297         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 298                 goto found;
 299
 300         label_len = be16_to_cpu(key->unicode_len) * 2;
 301         dbg("label unicode16 len %i", label_len);
 302         volume_id_set_label_raw(id, key->unicode, label_len);
 303         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 304
 305 found:
 306         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 307         id->type = "hfsplus";
 308
 309         return 0;
 310 }