extras/volume_id/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 #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
  36 #include "volume_id.h"
  37 #include "logging.h"
  38 #include "util.h"
  39 #include "hfs.h"
  40
  41 struct hfs_finder_info{
  42         uint32_t        boot_folder;
  43         uint32_t        start_app;
  44         uint32_t        open_folder;
  45         uint32_t        os9_folder;
  46         uint32_t        reserved;
  47         uint32_t        osx_folder;
  48         uint8_t         id[8];
  49 } __attribute__((__packed__));
  50
  51 struct hfs_mdb {
  52         uint8_t         signature[2];
  53         uint32_t        cr_date;
  54         uint32_t        ls_Mod;
  55         uint16_t        atrb;
  56         uint16_t        nm_fls;
  57         uint16_t        vbm_st;
  58         uint16_t        alloc_ptr;
  59         uint16_t        nm_al_blks;
  60         uint32_t        al_blk_size;
  61         uint32_t        clp_size;
  62         uint16_t        al_bl_st;
  63         uint32_t        nxt_cnid;
  64         uint16_t        free_bks;
  65         uint8_t         label_len;
  66         uint8_t         label[27];
  67         uint32_t        vol_bkup;
  68         uint16_t        vol_seq_num;
  69         uint32_t        wr_cnt;
  70         uint32_t        xt_clump_size;
  71         uint32_t        ct_clump_size;
  72         uint16_t        num_root_dirs;
  73         uint32_t        file_count;
  74         uint32_t        dir_count;
  75         struct hfs_finder_info finder_info;
  76         uint8_t         embed_sig[2];
  77         uint16_t        embed_startblock;
  78         uint16_t        embed_blockcount;
  79 } __attribute__((__packed__)) *hfs;
  80
  81 struct hfsplus_bnode_descriptor {
  82         uint32_t        next;
  83         uint32_t        prev;
  84         uint8_t         type;
  85         uint8_t         height;
  86         uint16_t        num_recs;
  87         uint16_t        reserved;
  88 } __attribute__((__packed__));
  89
  90 struct hfsplus_bheader_record {
  91         uint16_t        depth;
  92         uint32_t        root;
  93         uint32_t        leaf_count;
  94         uint32_t        leaf_head;
  95         uint32_t        leaf_tail;
  96         uint16_t        node_size;
  97 } __attribute__((__packed__));
  98
  99 struct hfsplus_catalog_key {
 100         uint16_t        key_len;
 101         uint32_t        parent_id;
 102         uint16_t        unicode_len;
 103         uint8_t         unicode[255 * 2];
 104 } __attribute__((__packed__));
 105
 106 struct hfsplus_extent {
 107         uint32_t        start_block;
 108         uint32_t        block_count;
 109 } __attribute__((__packed__));
 110
 111 #define HFSPLUS_EXTENT_COUNT            8
 112 struct hfsplus_fork {
 113         uint64_t        total_size;
 114         uint32_t        clump_size;
 115         uint32_t        total_blocks;
 116         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 117 } __attribute__((__packed__));
 118
 119 struct hfsplus_vol_header {
 120         uint8_t         signature[2];
 121         uint16_t        version;
 122         uint32_t        attributes;
 123         uint32_t        last_mount_vers;
 124         uint32_t        reserved;
 125         uint32_t        create_date;
 126         uint32_t        modify_date;
 127         uint32_t        backup_date;
 128         uint32_t        checked_date;
 129         uint32_t        file_count;
 130         uint32_t        folder_count;
 131         uint32_t        blocksize;
 132         uint32_t        total_blocks;
 133         uint32_t        free_blocks;
 134         uint32_t        next_alloc;
 135         uint32_t        rsrc_clump_sz;
 136         uint32_t        data_clump_sz;
 137         uint32_t        next_cnid;
 138         uint32_t        write_count;
 139         uint64_t        encodings_bmp;
 140         struct hfs_finder_info finder_info;
 141         struct hfsplus_fork alloc_file;
 142         struct hfsplus_fork ext_file;
 143         struct hfsplus_fork cat_file;
 144         struct hfsplus_fork attr_file;
 145         struct hfsplus_fork start_file;
 146 } __attribute__((__packed__)) *hfsplus;
 147
 148 #define HFS_SUPERBLOCK_OFFSET           0x400
 149 #define HFS_NODE_LEAF                   0xff
 150 #define HFSPLUS_POR_CNID                1
 151
 152 int volume_id_probe_hfs_hfsplus(struct volume_id *id, uint64_t off)
 153 {
 154         unsigned int blocksize;
 155         unsigned int cat_block;
 156         unsigned int ext_block_start;
 157         unsigned int ext_block_count;
 158         int ext;
 159         unsigned int leaf_node_head;
 160         unsigned int leaf_node_count;
 161         unsigned int leaf_node_size;
 162         unsigned int leaf_block;
 163         uint64_t leaf_off;
 164         unsigned int alloc_block_size;
 165         unsigned int alloc_first_block;
 166         unsigned int embed_first_block;
 167         unsigned int record_count;
 168         struct hfsplus_bnode_descriptor *descr;
 169         struct hfsplus_bheader_record *bnode;
 170         struct hfsplus_catalog_key *key;
 171         unsigned int label_len;
 172         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 173         const uint8_t *buf;
 174
 175         dbg("probing at offset 0x%llx", (unsigned long long) off);
 176
 177         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 178         if (buf == NULL)
 179                 return -1;
 180
 181         hfs = (struct hfs_mdb *) buf;
 182         if (memcmp(hfs->signature, "BD", 2) != 0)
 183                 goto checkplus;
 184
 185         /* it may be just a hfs wrapper for hfs+ */
 186         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 187                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 188                 dbg("alloc_block_size 0x%x", alloc_block_size);
 189
 190                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 191                 dbg("alloc_first_block 0x%x", alloc_first_block);
 192
 193                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 194                 dbg("embed_first_block 0x%x", embed_first_block);
 195
 196                 off += (alloc_first_block * 512) +
 197                        (embed_first_block * alloc_block_size);
 198                 dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);
 199
 200                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 201                 if (buf == NULL)
 202                         return -1;
 203                 goto checkplus;
 204         }
 205
 206         if (hfs->label_len > 0 && hfs->label_len < 28) {
 207                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 208                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 209         }
 210
 211         volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
 212
 213         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 214         id->type = "hfs";
 215
 216         return 0;
 217
 218 checkplus:
 219         hfsplus = (struct hfsplus_vol_header *) buf;
 220         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 221                 goto hfsplus;
 222         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 223                 goto hfsplus;
 224         return -1;
 225
 226 hfsplus:
 227         volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
 228
 229         blocksize = be32_to_cpu(hfsplus->blocksize);
 230         dbg("blocksize %u", blocksize);
 231
 232         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 233         cat_block = be32_to_cpu(extents[0].start_block);
 234         dbg("catalog start block 0x%x", cat_block);
 235
 236         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 237         if (buf == NULL)
 238                 goto found;
 239
 240         bnode = (struct hfsplus_bheader_record *)
 241                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 242
 243         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 244         dbg("catalog leaf node 0x%x", leaf_node_head);
 245
 246         leaf_node_size = be16_to_cpu(bnode->node_size);
 247         dbg("leaf node size 0x%x", leaf_node_size);
 248
 249         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 250         dbg("leaf node count 0x%x", leaf_node_count);
 251         if (leaf_node_count == 0)
 252                 goto found;
 253
 254         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 255
 256         /* get physical location */
 257         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 258                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 259                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 260                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 261
 262                 if (ext_block_count == 0)
 263                         goto found;
 264
 265                 /* this is our extent */
 266                 if (leaf_block < ext_block_count)
 267                         break;
 268
 269                 leaf_block -= ext_block_count;
 270         }
 271         if (ext == HFSPLUS_EXTENT_COUNT)
 272                 goto found;
 273         dbg("found block in extent %i", ext);
 274
 275         leaf_off = (ext_block_start + leaf_block) * blocksize;
 276
 277         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 278         if (buf == NULL)
 279                 goto found;
 280
 281         descr = (struct hfsplus_bnode_descriptor *) buf;
 282         dbg("descriptor type 0x%x", descr->type);
 283
 284         record_count = be16_to_cpu(descr->num_recs);
 285         dbg("number of records %u", record_count);
 286         if (record_count == 0)
 287                 goto found;
 288
 289         if (descr->type != HFS_NODE_LEAF)
 290                 goto found;
 291
 292         key = (struct hfsplus_catalog_key *)
 293                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 294
 295         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 296         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 297                 goto found;
 298
 299         label_len = be16_to_cpu(key->unicode_len) * 2;
 300         dbg("label unicode16 len %i", label_len);
 301         volume_id_set_label_raw(id, key->unicode, label_len);
 302         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 303
 304 found:
 305         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 306         id->type = "hfsplus";
 307
 308         return 0;
 309 }