busybox/util-linux/volume_id/hfs.c

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/*
* volume_id - reads filesystem label and uuid
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "volume_id_internal.h"
struct hfs_finder_info{
uint32_t boot_folder;
uint32_t start_app;
uint32_t open_folder;
uint32_t os9_folder;
uint32_t reserved;
uint32_t osx_folder;
uint8_t id[8];
} __attribute__((__packed__));
struct hfs_mdb {
uint8_t signature[2];
uint32_t cr_date;
uint32_t ls_Mod;
uint16_t atrb;
uint16_t nm_fls;
uint16_t vbm_st;
uint16_t alloc_ptr;
uint16_t nm_al_blks;
uint32_t al_blk_size;
uint32_t clp_size;
uint16_t al_bl_st;
uint32_t nxt_cnid;
uint16_t free_bks;
uint8_t label_len;
uint8_t label[27];
uint32_t vol_bkup;
uint16_t vol_seq_num;
uint32_t wr_cnt;
uint32_t xt_clump_size;
uint32_t ct_clump_size;
uint16_t num_root_dirs;
uint32_t file_count;
uint32_t dir_count;
struct hfs_finder_info finder_info;
uint8_t embed_sig[2];
uint16_t embed_startblock;
uint16_t embed_blockcount;
} __attribute__((__packed__));
struct hfsplus_bnode_descriptor {
uint32_t next;
uint32_t prev;
uint8_t type;
uint8_t height;
uint16_t num_recs;
uint16_t reserved;
} __attribute__((__packed__));
struct hfsplus_bheader_record {
uint16_t depth;
uint32_t root;
uint32_t leaf_count;
uint32_t leaf_head;
uint32_t leaf_tail;
uint16_t node_size;
} __attribute__((__packed__));
struct hfsplus_catalog_key {
uint16_t key_len;
uint32_t parent_id;
uint16_t unicode_len;
uint8_t unicode[255 * 2];
} __attribute__((__packed__));
struct hfsplus_extent {
uint32_t start_block;
uint32_t block_count;
} __attribute__((__packed__));
#define HFSPLUS_EXTENT_COUNT 8
struct hfsplus_fork {
uint64_t total_size;
uint32_t clump_size;
uint32_t total_blocks;
struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
} __attribute__((__packed__));
struct hfsplus_vol_header {
uint8_t signature[2];
uint16_t version;
uint32_t attributes;
uint32_t last_mount_vers;
uint32_t reserved;
uint32_t create_date;
uint32_t modify_date;
uint32_t backup_date;
uint32_t checked_date;
uint32_t file_count;
uint32_t folder_count;
uint32_t blocksize;
uint32_t total_blocks;
uint32_t free_blocks;
uint32_t next_alloc;
uint32_t rsrc_clump_sz;
uint32_t data_clump_sz;
uint32_t next_cnid;
uint32_t write_count;
uint64_t encodings_bmp;
struct hfs_finder_info finder_info;
struct hfsplus_fork alloc_file;
struct hfsplus_fork ext_file;
struct hfsplus_fork cat_file;
struct hfsplus_fork attr_file;
struct hfsplus_fork start_file;
} __attribute__((__packed__));
#define HFS_SUPERBLOCK_OFFSET 0x400
#define HFS_NODE_LEAF 0xff
#define HFSPLUS_POR_CNID 1
int volume_id_probe_hfs_hfsplus(struct volume_id *id, uint64_t off)
{
unsigned blocksize;
unsigned cat_block;
unsigned ext_block_start;
unsigned ext_block_count;
int ext;
unsigned leaf_node_head;
unsigned leaf_node_count;
unsigned leaf_node_size;
unsigned leaf_block;
uint64_t leaf_off;
unsigned alloc_block_size;
unsigned alloc_first_block;
unsigned embed_first_block;
unsigned record_count;
struct hfsplus_vol_header *hfsplus;
struct hfsplus_bnode_descriptor *descr;
struct hfsplus_bheader_record *bnode;
struct hfsplus_catalog_key *key;
unsigned label_len;
struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
struct hfs_mdb *hfs;
const uint8_t *buf;
dbg("probing at offset 0x%llx", (unsigned long long) off);
buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
if (buf == NULL)
return -1;
hfs = (struct hfs_mdb *) buf;
if (hfs->signature[0] != 'B' || hfs->signature[1] != 'D')
goto checkplus;
/* it may be just a hfs wrapper for hfs+ */
if (memcmp(hfs->embed_sig, "H+", 2) == 0) {
alloc_block_size = be32_to_cpu(hfs->al_blk_size);
dbg("alloc_block_size 0x%x", alloc_block_size);
alloc_first_block = be16_to_cpu(hfs->al_bl_st);
dbg("alloc_first_block 0x%x", alloc_first_block);
embed_first_block = be16_to_cpu(hfs->embed_startblock);
dbg("embed_first_block 0x%x", embed_first_block);
off += (alloc_first_block * 512) +
(embed_first_block * alloc_block_size);
dbg("hfs wrapped hfs+ found at offset 0x%llx", (unsigned long long) off);
buf = volume_id_get_buffer(id, off + HFS_SUPERBLOCK_OFFSET, 0x200);
if (buf == NULL)
return -1;
goto checkplus;
}
if (hfs->label_len > 0 && hfs->label_len < 28) {
volume_id_set_label_raw(id, hfs->label, hfs->label_len);
volume_id_set_label_string(id, hfs->label, hfs->label_len) ;
}
volume_id_set_uuid(id, hfs->finder_info.id, UUID_HFS);
volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
id->type = "hfs";
return 0;
checkplus:
hfsplus = (struct hfsplus_vol_header *) buf;
if (hfs->signature[0] == 'H')
if (hfs->signature[1] == '+' || hfs->signature[1] == 'X')
goto hfsplus;
return -1;
hfsplus:
volume_id_set_uuid(id, hfsplus->finder_info.id, UUID_HFS);
blocksize = be32_to_cpu(hfsplus->blocksize);
dbg("blocksize %u", blocksize);
memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
cat_block = be32_to_cpu(extents[0].start_block);
dbg("catalog start block 0x%x", cat_block);
buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
if (buf == NULL)
goto found;
bnode = (struct hfsplus_bheader_record *)
&buf[sizeof(struct hfsplus_bnode_descriptor)];
leaf_node_head = be32_to_cpu(bnode->leaf_head);
dbg("catalog leaf node 0x%x", leaf_node_head);
leaf_node_size = be16_to_cpu(bnode->node_size);
dbg("leaf node size 0x%x", leaf_node_size);
leaf_node_count = be32_to_cpu(bnode->leaf_count);
dbg("leaf node count 0x%x", leaf_node_count);
if (leaf_node_count == 0)
goto found;
leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
/* get physical location */
for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
ext_block_start = be32_to_cpu(extents[ext].start_block);
ext_block_count = be32_to_cpu(extents[ext].block_count);
dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
if (ext_block_count == 0)
goto found;
/* this is our extent */
if (leaf_block < ext_block_count)
break;
leaf_block -= ext_block_count;
}
if (ext == HFSPLUS_EXTENT_COUNT)
goto found;
dbg("found block in extent %i", ext);
leaf_off = (ext_block_start + leaf_block) * blocksize;
buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
if (buf == NULL)
goto found;
descr = (struct hfsplus_bnode_descriptor *) buf;
dbg("descriptor type 0x%x", descr->type);
record_count = be16_to_cpu(descr->num_recs);
dbg("number of records %u", record_count);
if (record_count == 0)
goto found;
if (descr->type != HFS_NODE_LEAF)
goto found;
key = (struct hfsplus_catalog_key *)
&buf[sizeof(struct hfsplus_bnode_descriptor)];
dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
if (key->parent_id != cpu_to_be32(HFSPLUS_POR_CNID))
goto found;
label_len = be16_to_cpu(key->unicode_len) * 2;
dbg("label unicode16 len %i", label_len);
volume_id_set_label_raw(id, key->unicode, label_len);
volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
found:
volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
id->type = "hfsplus";
return 0;
}