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