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 "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 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 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 int volume_id_probe_hfs_hfsplus(struct volume_id *id, uint64_t off)
 141 {
 142         unsigned int blocksize;
 143         unsigned int cat_block;
 144         unsigned int ext_block_start;
 145         unsigned int ext_block_count;
 146         int ext;
 147         unsigned int leaf_node_head;
 148         unsigned int leaf_node_count;
 149         unsigned int leaf_node_size;
 150         unsigned int leaf_block;
 151         uint64_t leaf_off;
 152         unsigned int alloc_block_size;
 153         unsigned int alloc_first_block;
 154         unsigned int embed_first_block;
 155         unsigned int record_count;
 156         struct hfsplus_bnode_descriptor *descr;
 157         struct hfsplus_bheader_record *bnode;
 158         struct hfsplus_catalog_key *key;
 159         unsigned int label_len;
 160         struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
 161         const uint8_t *buf;
 162
 163         dbg("probing at offset 0x%llx", (unsigned long long) off);
 164
 165         buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 166         if (buf == NULL)
 167                 return -1;
 168
 169         hfs = (struct hfs_mdb *) buf;
 170         if (memcmp(hfs->signature, "BD", 2) != 0)
 171                 goto checkplus;
 172
 173         /* it may be just a hfs wrapper for hfs+ */
 174         if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
 175                 alloc_block_size = be32_to_cpu(hfs->al_blk_size);
 176                 dbg("alloc_block_size 0x%x", alloc_block_size);
 177
 178                 alloc_first_block = be16_to_cpu(hfs->al_bl_st);
 179                 dbg("alloc_first_block 0x%x", alloc_first_block);
 180
 181                 embed_first_block = be16_to_cpu(hfs->embed_startblock);
 182                 dbg("embed_first_block 0x%x", embed_first_block);
 183
 184                 off += (alloc_first_block * 512) +
 185                        (embed_first_block * alloc_block_size);
 186                 dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);
 187
 188                 buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
 189                 if (buf == NULL)
 190                         return -1;
 191                 goto checkplus;
 192         }
 193
 194         if (hfs->label_len > 0 && hfs->label_len < 28) {
 195                 volume_id_set_label_raw(id, hfs->label, hfs->label_len);
 196                 volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
 197         }
 198
 199         volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
 200
 201         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 202         id->type = "hfs";
 203
 204         return 0;
 205
 206 checkplus:
 207         hfsplus = (struct hfsplus_vol_header *) buf;
 208         if (memcmp(hfsplus->signature, "H+", 2) == 0)
 209                 goto hfsplus;
 210         if (memcmp(hfsplus->signature, "HX", 2) == 0)
 211                 goto hfsplus;
 212         return -1;
 213
 214 hfsplus:
 215         volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
 216
 217         blocksize = be32_to_cpu(hfsplus->blocksize);
 218         dbg("blocksize %u", blocksize);
 219
 220         memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
 221         cat_block = be32_to_cpu(extents[0].start_block);
 222         dbg("catalog start block 0x%x", cat_block);
 223
 224         buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
 225         if (buf == NULL)
 226                 goto found;
 227
 228         bnode = (struct hfsplus_bheader_record *)
 229                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 230
 231         leaf_node_head = be32_to_cpu(bnode->leaf_head);
 232         dbg("catalog leaf node 0x%x", leaf_node_head);
 233
 234         leaf_node_size = be16_to_cpu(bnode->node_size);
 235         dbg("leaf node size 0x%x", leaf_node_size);
 236
 237         leaf_node_count = be32_to_cpu(bnode->leaf_count);
 238         dbg("leaf node count 0x%x", leaf_node_count);
 239         if (leaf_node_count == 0)
 240                 goto found;
 241
 242         leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
 243
 244         /* get physical location */
 245         for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
 246                 ext_block_start = be32_to_cpu(extents[ext].start_block);
 247                 ext_block_count = be32_to_cpu(extents[ext].block_count);
 248                 dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
 249
 250                 if (ext_block_count == 0)
 251                         goto found;
 252
 253                 /* this is our extent */
 254                 if (leaf_block < ext_block_count)
 255                         break;
 256
 257                 leaf_block -= ext_block_count;
 258         }
 259         if (ext == HFSPLUS_EXTENT_COUNT)
 260                 goto found;
 261         dbg("found block in extent %i", ext);
 262
 263         leaf_off = (ext_block_start + leaf_block) * blocksize;
 264
 265         buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
 266         if (buf == NULL)
 267                 goto found;
 268
 269         descr = (struct hfsplus_bnode_descriptor *) buf;
 270         dbg("descriptor type 0x%x", descr->type);
 271
 272         record_count = be16_to_cpu(descr->num_recs);
 273         dbg("number of records %u", record_count);
 274         if (record_count == 0)
 275                 goto found;
 276
 277         if (descr->type != HFS_NODE_LEAF)
 278                 goto found;
 279
 280         key = (struct hfsplus_catalog_key *)
 281                 &buf[sizeof(struct hfsplus_bnode_descriptor)];
 282
 283         dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
 284         if (be32_to_cpu(key->parent_id) != HFSPLUS_POR_CNID)
 285                 goto found;
 286
 287         label_len = be16_to_cpu(key->unicode_len) * 2;
 288         dbg("label unicode16 len %i", label_len);
 289         volume_id_set_label_raw(id, key->unicode, label_len);
 290         volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
 291
 292 found:
 293         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 294         id->type = "hfsplus";
 295
 296         return 0;
 297 }