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 "libvolume_id-private.h"
  28 #include "util.h"
  29 #include "md5.h"
  30
  31 struct hfs_finder_info{
  32         uint32_t        boot_folder;
  33         uint32_t        start_app;
  34         uint32_t        open_folder;
  35         uint32_t        os9_folder;
  36         uint32_t        reserved;
  37         uint32_t        osx_folder;
  38         uint8_t         id[8];
  39 } PACKED;
  40
  41 static struct hfs_mdb {
  42         uint8_t         signature[2];
  43         uint32_t        cr_date;
  44         uint32_t        ls_Mod;
  45         uint16_t        atrb;
  46         uint16_t        nm_fls;
  47         uint16_t        vbm_st;
  48         uint16_t        alloc_ptr;
  49         uint16_t        nm_al_blks;
  50         uint32_t        al_blk_size;
  51         uint32_t        clp_size;
  52         uint16_t        al_bl_st;
  53         uint32_t        nxt_cnid;
  54         uint16_t        free_bks;
  55         uint8_t         label_len;
  56         uint8_t         label[27];
  57         uint32_t        vol_bkup;
  58         uint16_t        vol_seq_num;
  59         uint32_t        wr_cnt;
  60         uint32_t        xt_clump_size;
  61         uint32_t        ct_clump_size;
  62         uint16_t        num_root_dirs;
  63         uint32_t        file_count;
  64         uint32_t        dir_count;
  65         struct hfs_finder_info finder_info;
  66         uint8_t         embed_sig[2];
  67         uint16_t        embed_startblock;
  68         uint16_t        embed_blockcount;
  69 } PACKED *hfs;
  70
  71 struct hfsplus_bnode_descriptor {
  72         uint32_t        next;
  73         uint32_t        prev;
  74         uint8_t         type;
  75         uint8_t         height;
  76         uint16_t        num_recs;
  77         uint16_t        reserved;
  78 } PACKED;
  79
  80 struct hfsplus_bheader_record {
  81         uint16_t        depth;
  82         uint32_t        root;
  83         uint32_t        leaf_count;
  84         uint32_t        leaf_head;
  85         uint32_t        leaf_tail;
  86         uint16_t        node_size;
  87 } PACKED;
  88
  89 struct hfsplus_catalog_key {
  90         uint16_t        key_len;
  91         uint32_t        parent_id;
  92         uint16_t        unicode_len;
  93         uint8_t         unicode[255 * 2];
  94 } PACKED;
  95
  96 struct hfsplus_extent {
  97         uint32_t        start_block;
  98         uint32_t        block_count;
  99 } PACKED;
 100
 101 #define HFSPLUS_EXTENT_COUNT            8
 102 struct hfsplus_fork {
 103         uint64_t        total_size;
 104         uint32_t        clump_size;
 105         uint32_t        total_blocks;
 106         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 107 } PACKED;
 108
 109 static struct hfsplus_vol_header {
 110         uint8_t         signature[2];
 111         uint16_t        version;
 112         uint32_t        attributes;
 113         uint32_t        last_mount_vers;
 114         uint32_t        reserved;
 115         uint32_t        create_date;
 116         uint32_t        modify_date;
 117         uint32_t        backup_date;
 118         uint32_t        checked_date;
 119         uint32_t        file_count;
 120         uint32_t        folder_count;
 121         uint32_t        blocksize;
 122         uint32_t        total_blocks;
 123         uint32_t        free_blocks;
 124         uint32_t        next_alloc;
 125         uint32_t        rsrc_clump_sz;
 126         uint32_t        data_clump_sz;
 127         uint32_t        next_cnid;
 128         uint32_t        write_count;
 129         uint64_t        encodings_bmp;
 130         struct hfs_finder_info finder_info;
 131         struct hfsplus_fork alloc_file;
 132         struct hfsplus_fork ext_file;
 133         struct hfsplus_fork cat_file;
 134         struct hfsplus_fork attr_file;
 135         struct hfsplus_fork start_file;
 136 } PACKED *hfsplus;
 137
 138 #define HFS_SUPERBLOCK_OFFSET           0x400
 139 #define HFS_NODE_LEAF                   0xff
 140 #define HFSPLUS_POR_CNID                1
 141
 142 static void hfsid_set_uuid(struct volume_id *id, const uint8_t *hfs_id)
 143 {
 144         struct md5_ctx md5c;
 145         static const uint8_t hash_init[16] = {
 146                 0xb3, 0xe2, 0x0f, 0x39, 0xf2, 0x92, 0x11, 0xd6,
 147                 0x97, 0xa4, 0x00, 0x30, 0x65, 0x43, 0xec, 0xac
 148         };
 149         uint8_t uuid[16];
 150
 151         if (*((uint64_t *)hfs_id) == 0)
 152                 return;
 153
 154         md5_init(&md5c);
 155         md5_update(&md5c, hash_init, 16);
 156         md5_update(&md5c, hfs_id, 8);
 157         md5_final(&md5c, uuid);
 158
 159         uuid[6] = 0x30 | (uuid[6] & 0x0f);
 160         uuid[8] = 0x80 | (uuid[8] & 0x3f);
 161         volume_id_set_uuid(id, uuid, 0, UUID_DCE);
 162 }
 163
 164 int volume_id_probe_hfs_hfsplus(struct volume_id *id, uint64_t off, uint64_t size)
 165 {
 166         unsigned int blocksize;
 167         unsigned int cat_block;
 168         unsigned int ext_block_start;
 169         unsigned int ext_block_count;
 170         int ext;
 171         unsigned int leaf_node_head;
 172         unsigned int leaf_node_count;
 173         unsigned int leaf_node_size;
 174         unsigned int leaf_block;
 175         uint64_t leaf_off;
 176         unsigned int alloc_block_size;
 177         unsigned int alloc_first_block;
 178         unsigned int embed_first_block;
 179         unsigned int record_count;
 180         struct hfsplus_bnode_descriptor *descr;
 181         struct hfsplus_bheader_record *bnode;
 182         struct hfsplus_catalog_key *key;
 183         unsigned int label_len;
 184         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 185         const uint8_t *buf;
 186
 187         info("probing at offset 0x%llx\n", (unsigned long long) off);
 188
 189         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 190         if (buf == NULL)
 191                 return -1;
 192
 193         hfs = (struct hfs_mdb *) buf;
 194         if (memcmp(hfs->signature, "BD", 2) != 0)
 195                 goto checkplus;
 196
 197         /* it may be just a hfs wrapper for hfs+ */
 198         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 199                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 200                 dbg("alloc_block_size 0x%x\n", alloc_block_size);
 201
 202                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 203                 dbg("alloc_first_block 0x%x\n", alloc_first_block);
 204
 205                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 206                 dbg("embed_first_block 0x%x\n", embed_first_block);
 207
 208                 off += (alloc_first_block * 512) +
 209                        (embed_first_block * alloc_block_size);
 210                 dbg("hfs wrapped hfs+ found at offset 0x%llx\n", (unsigned long long) off);
 211
 212                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 213                 if (buf == NULL)
 214                         return -1;
 215                 goto checkplus;
 216         }
 217
 218         if (hfs->label_len > 0 && hfs->label_len < 28) {
 219                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 220                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 221         }
 222
 223         hfsid_set_uuid(id, hfs->finder_info.id);
 224
 225         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 226         id->type = "hfs";
 227
 228         return 0;
 229
 230 checkplus:
 231         hfsplus = (struct hfsplus_vol_header *) buf;
 232         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 233                 goto hfsplus;
 234         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 235                 goto hfsplus;
 236         return -1;
 237
 238 hfsplus:
 239         hfsid_set_uuid(id, hfsplus->finder_info.id);
 240
 241         blocksize = be32_to_cpu(hfsplus->blocksize);
 242         dbg("blocksize %u\n", blocksize);
 243
 244         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 245         cat_block = be32_to_cpu(extents[0].start_block);
 246         dbg("catalog start block 0x%x\n", cat_block);
 247
 248         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 249         if (buf == NULL)
 250                 goto found;
 251
 252         bnode = (struct hfsplus_bheader_record *)
 253                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 254
 255         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 256         dbg("catalog leaf node 0x%x\n", leaf_node_head);
 257
 258         leaf_node_size = be16_to_cpu(bnode->node_size);
 259         dbg("leaf node size 0x%x\n", leaf_node_size);
 260
 261         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 262         dbg("leaf node count 0x%x\n", leaf_node_count);
 263         if (leaf_node_count == 0)
 264                 goto found;
 265
 266         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 267
 268         /* get physical location */
 269         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 270                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 271                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 272                 dbg("extent start block 0x%x, count 0x%x\n", ext_block_start, ext_block_count);
 273
 274                 if (ext_block_count == 0)
 275                         goto found;
 276
 277                 /* this is our extent */
 278                 if (leaf_block < ext_block_count)
 279                         break;
 280
 281                 leaf_block -= ext_block_count;
 282         }
 283         if (ext == HFSPLUS_EXTENT_COUNT)
 284                 goto found;
 285         dbg("found block in extent %i\n", ext);
 286
 287         leaf_off = (ext_block_start + leaf_block) * blocksize;
 288
 289         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 290         if (buf == NULL)
 291                 goto found;
 292
 293         descr = (struct hfsplus_bnode_descriptor *) buf;
 294         dbg("descriptor type 0x%x\n", descr->type);
 295
 296         record_count = be16_to_cpu(descr->num_recs);
 297         dbg("number of records %u\n", record_count);
 298         if (record_count == 0)
 299                 goto found;
 300
 301         if (descr->type != HFS_NODE_LEAF)
 302                 goto found;
 303
 304         key = (struct hfsplus_catalog_key *)
 305                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 306
 307         dbg("parent id 0x%x\n", be32_to_cpu(key->parent_id));
 308         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 309                 goto found;
 310
 311         label_len = be16_to_cpu(key->unicode_len) * 2;
 312         dbg("label unicode16 len %i\n", label_len);
 313         volume_id_set_label_raw(id, key->unicode, label_len);
 314         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 315
 316 found:
 317         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 318         id->type = "hfsplus";
 319
 320         return 0;
 321 }