extras/volume_id/lib/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 program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  */
  10
  11 #ifndef _GNU_SOURCE
  12 #define _GNU_SOURCE 1
  13 #endif
  14
  15 #ifdef HAVE_CONFIG_H
  16 #  include <config.h>
  17 #endif
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25
  26 #include "libvolume_id.h"
  27 #include "util.h"
  28
  29 struct hfs_finder_info{
  30         uint32_t        boot_folder;
  31         uint32_t        start_app;
  32         uint32_t        open_folder;
  33         uint32_t        os9_folder;
  34         uint32_t        reserved;
  35         uint32_t        osx_folder;
  36         uint8_t         id[8];
  37 } PACKED;
  38
  39 static struct hfs_mdb {
  40         uint8_t         signature[2];
  41         uint32_t        cr_date;
  42         uint32_t        ls_Mod;
  43         uint16_t        atrb;
  44         uint16_t        nm_fls;
  45         uint16_t        vbm_st;
  46         uint16_t        alloc_ptr;
  47         uint16_t        nm_al_blks;
  48         uint32_t        al_blk_size;
  49         uint32_t        clp_size;
  50         uint16_t        al_bl_st;
  51         uint32_t        nxt_cnid;
  52         uint16_t        free_bks;
  53         uint8_t         label_len;
  54         uint8_t         label[27];
  55         uint32_t        vol_bkup;
  56         uint16_t        vol_seq_num;
  57         uint32_t        wr_cnt;
  58         uint32_t        xt_clump_size;
  59         uint32_t        ct_clump_size;
  60         uint16_t        num_root_dirs;
  61         uint32_t        file_count;
  62         uint32_t        dir_count;
  63         struct hfs_finder_info finder_info;
  64         uint8_t         embed_sig[2];
  65         uint16_t        embed_startblock;
  66         uint16_t        embed_blockcount;
  67 } PACKED *hfs;
  68
  69 struct hfsplus_bnode_descriptor {
  70         uint32_t        next;
  71         uint32_t        prev;
  72         uint8_t         type;
  73         uint8_t         height;
  74         uint16_t        num_recs;
  75         uint16_t        reserved;
  76 } PACKED;
  77
  78 struct hfsplus_bheader_record {
  79         uint16_t        depth;
  80         uint32_t        root;
  81         uint32_t        leaf_count;
  82         uint32_t        leaf_head;
  83         uint32_t        leaf_tail;
  84         uint16_t        node_size;
  85 } PACKED;
  86
  87 struct hfsplus_catalog_key {
  88         uint16_t        key_len;
  89         uint32_t        parent_id;
  90         uint16_t        unicode_len;
  91         uint8_t         unicode[255 * 2];
  92 } PACKED;
  93
  94 struct hfsplus_extent {
  95         uint32_t        start_block;
  96         uint32_t        block_count;
  97 } PACKED;
  98
  99 #define HFSPLUS_EXTENT_COUNT            8
 100 struct hfsplus_fork {
 101         uint64_t        total_size;
 102         uint32_t        clump_size;
 103         uint32_t        total_blocks;
 104         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 105 } PACKED;
 106
 107 static struct hfsplus_vol_header {
 108         uint8_t         signature[2];
 109         uint16_t        version;
 110         uint32_t        attributes;
 111         uint32_t        last_mount_vers;
 112         uint32_t        reserved;
 113         uint32_t        create_date;
 114         uint32_t        modify_date;
 115         uint32_t        backup_date;
 116         uint32_t        checked_date;
 117         uint32_t        file_count;
 118         uint32_t        folder_count;
 119         uint32_t        blocksize;
 120         uint32_t        total_blocks;
 121         uint32_t        free_blocks;
 122         uint32_t        next_alloc;
 123         uint32_t        rsrc_clump_sz;
 124         uint32_t        data_clump_sz;
 125         uint32_t        next_cnid;
 126         uint32_t        write_count;
 127         uint64_t        encodings_bmp;
 128         struct hfs_finder_info finder_info;
 129         struct hfsplus_fork alloc_file;
 130         struct hfsplus_fork ext_file;
 131         struct hfsplus_fork cat_file;
 132         struct hfsplus_fork attr_file;
 133         struct hfsplus_fork start_file;
 134 } PACKED *hfsplus;
 135
 136 #define HFS_SUPERBLOCK_OFFSET           0x400
 137 #define HFS_NODE_LEAF                   0xff
 138 #define HFSPLUS_POR_CNID                1
 139
 140 static void hfsid_set_uuid(struct volume_id *id, const uint8_t *hfs_id)
 141 {
 142 #if 0
 143         MD5_CTX md5c;
 144         static const uint8_t hash_init[16] = {
 145                 0xb3, 0xe2, 0x0f, 0x39, 0xf2, 0x92, 0x11, 0xd6,
 146                 0x97, 0xa4, 0x00, 0x30, 0x65, 0x43, 0xec, 0xac
 147         };
 148         uint8_t uuid[16];
 149
 150         if (*((uint64_t *)hfs_id) == 0)
 151                 return;
 152
 153         MD5_Init(&md5c);
 154         MD5_Update(&md5c, &hash_init, 16);
 155         MD5_Update(&md5c, hfs_id, 8);
 156         MD5_Final(uuid, &md5c);
 157
 158         uuid[6] = 0x30 | (uuid[6] & 0x0f);
 159         uuid[8] = 0x80 | (uuid[8] & 0x3f);
 160         volume_id_set_uuid(id, uuid, UUID_DCE);
 161 #endif
 162
 163         volume_id_set_uuid(id, hfs_id, 0, UUID_64BIT_BE);
 164 }
 165
 166 int volume_id_probe_hfs_hfsplus(struct volume_id *id, uint64_t off, uint64_t size)
 167 {
 168         unsigned int blocksize;
 169         unsigned int cat_block;
 170         unsigned int ext_block_start;
 171         unsigned int ext_block_count;
 172         int ext;
 173         unsigned int leaf_node_head;
 174         unsigned int leaf_node_count;
 175         unsigned int leaf_node_size;
 176         unsigned int leaf_block;
 177         uint64_t leaf_off;
 178         unsigned int alloc_block_size;
 179         unsigned int alloc_first_block;
 180         unsigned int embed_first_block;
 181         unsigned int record_count;
 182         struct hfsplus_bnode_descriptor *descr;
 183         struct hfsplus_bheader_record *bnode;
 184         struct hfsplus_catalog_key *key;
 185         unsigned int label_len;
 186         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 187         const uint8_t *buf;
 188
 189         info("probing at offset 0x%llx", (unsigned long long) off);
 190
 191         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 192         if (buf == NULL)
 193                 return -1;
 194
 195         hfs = (struct hfs_mdb *) buf;
 196         if (memcmp(hfs->signature, "BD", 2) != 0)
 197                 goto checkplus;
 198
 199         /* it may be just a hfs wrapper for hfs+ */
 200         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 201                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 202                 dbg("alloc_block_size 0x%x", alloc_block_size);
 203
 204                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 205                 dbg("alloc_first_block 0x%x", alloc_first_block);
 206
 207                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 208                 dbg("embed_first_block 0x%x", embed_first_block);
 209
 210                 off += (alloc_first_block * 512) +
 211                        (embed_first_block * alloc_block_size);
 212                 dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);
 213
 214                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 215                 if (buf == NULL)
 216                         return -1;
 217                 goto checkplus;
 218         }
 219
 220         if (hfs->label_len > 0 && hfs->label_len < 28) {
 221                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 222                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 223         }
 224
 225         hfsid_set_uuid(id, hfs->finder_info.id);
 226
 227         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 228         id->type = "hfs";
 229
 230         return 0;
 231
 232 checkplus:
 233         hfsplus = (struct hfsplus_vol_header *) buf;
 234         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 235                 goto hfsplus;
 236         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 237                 goto hfsplus;
 238         return -1;
 239
 240 hfsplus:
 241         hfsid_set_uuid(id, hfsplus->finder_info.id);
 242
 243         blocksize = be32_to_cpu(hfsplus->blocksize);
 244         dbg("blocksize %u", blocksize);
 245
 246         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 247         cat_block = be32_to_cpu(extents[0].start_block);
 248         dbg("catalog start block 0x%x", cat_block);
 249
 250         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 251         if (buf == NULL)
 252                 goto found;
 253
 254         bnode = (struct hfsplus_bheader_record *)
 255                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 256
 257         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 258         dbg("catalog leaf node 0x%x", leaf_node_head);
 259
 260         leaf_node_size = be16_to_cpu(bnode->node_size);
 261         dbg("leaf node size 0x%x", leaf_node_size);
 262
 263         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 264         dbg("leaf node count 0x%x", leaf_node_count);
 265         if (leaf_node_count == 0)
 266                 goto found;
 267
 268         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 269
 270         /* get physical location */
 271         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 272                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 273                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 274                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 275
 276                 if (ext_block_count == 0)
 277                         goto found;
 278
 279                 /* this is our extent */
 280                 if (leaf_block < ext_block_count)
 281                         break;
 282
 283                 leaf_block -= ext_block_count;
 284         }
 285         if (ext == HFSPLUS_EXTENT_COUNT)
 286                 goto found;
 287         dbg("found block in extent %i", ext);
 288
 289         leaf_off = (ext_block_start + leaf_block) * blocksize;
 290
 291         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 292         if (buf == NULL)
 293                 goto found;
 294
 295         descr = (struct hfsplus_bnode_descriptor *) buf;
 296         dbg("descriptor type 0x%x", descr->type);
 297
 298         record_count = be16_to_cpu(descr->num_recs);
 299         dbg("number of records %u", record_count);
 300         if (record_count == 0)
 301                 goto found;
 302
 303         if (descr->type != HFS_NODE_LEAF)
 304                 goto found;
 305
 306         key = (struct hfsplus_catalog_key *)
 307                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 308
 309         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 310         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 311                 goto found;
 312
 313         label_len = be16_to_cpu(key->unicode_len) * 2;
 314         dbg("label unicode16 len %i", label_len);
 315         volume_id_set_label_raw(id, key->unicode, label_len);
 316         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 317
 318 found:
 319         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 320         id->type = "hfsplus";
 321
 322         return 0;
 323 }