1 /*
2  * volume_id - reads filesystem label and uuid
3  *
4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
5  *
6  *	This library is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU Lesser General Public
8  *	License as published by the Free Software Foundation; either
9  *	version 2.1 of the License, or (at your option) any later version.
10  *
11  *	This library is distributed in the hope that it will be useful,
12  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  *	Lesser General Public License for more details.
15  *
16  *	You should have received a copy of the GNU Lesser General Public
17  *	License along with this library; if not, write to the Free Software
18  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  */
20 //config:config FEATURE_VOLUMEID_HFS
21 //config:	bool "hfs filesystem"
22 //config:	default y
23 //config:	depends on VOLUMEID
24 
25 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_HFS) += hfs.o
26 
27 #include "volume_id_internal.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;
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;
135 
136 #define HFS_SUPERBLOCK_OFFSET		0x400
137 #define HFS_NODE_LEAF			0xff
138 #define HFSPLUS_POR_CNID		1
139 
hfs_set_uuid(struct volume_id * id,const uint8_t * hfs_id)140 static void FAST_FUNC hfs_set_uuid(struct volume_id *id, const uint8_t *hfs_id)
141 {
142 #define hfs_id_len 8
143 	md5_ctx_t md5c;
144 	uint8_t uuid[16];
145 	unsigned i;
146 
147 	for (i = 0; i < hfs_id_len; i++)
148 		if (hfs_id[i] != 0)
149 			goto do_md5;
150 	return;
151  do_md5:
152 	md5_begin(&md5c);
153 	md5_hash(&md5c, "\263\342\17\71\362\222\21\326\227\244\0\60\145\103\354\254", 16);
154 	md5_hash(&md5c, hfs_id, hfs_id_len);
155 	md5_end(&md5c, uuid);
156 	uuid[6] = 0x30 | (uuid[6] & 0x0f);
157 	uuid[8] = 0x80 | (uuid[8] & 0x3f);
158 	volume_id_set_uuid(id, uuid, UUID_DCE);
159 }
160 
volume_id_probe_hfs_hfsplus(struct volume_id * id)161 int FAST_FUNC volume_id_probe_hfs_hfsplus(struct volume_id *id /*,uint64_t off*/)
162 {
163 	uint64_t off = 0;
164 	unsigned blocksize;
165 	unsigned cat_block;
166 	unsigned ext_block_start;
167 	unsigned ext_block_count;
168 	int ext;
169 	unsigned leaf_node_head;
170 	unsigned leaf_node_count;
171 	unsigned leaf_node_size;
172 	unsigned leaf_block;
173 	uint64_t leaf_off;
174 	unsigned alloc_block_size;
175 	unsigned alloc_first_block;
176 	unsigned embed_first_block;
177 	unsigned record_count;
178 	struct hfsplus_vol_header *hfsplus;
179 	struct hfsplus_bnode_descriptor *descr;
180 	struct hfsplus_bheader_record *bnode;
181 	struct hfsplus_catalog_key *key;
182 	unsigned label_len;
183 	struct hfsplus_extent extents[HFSPLUS_EXTENT_COUNT];
184 	struct hfs_mdb *hfs;
185 	const uint8_t *buf;
186 
187 	dbg("probing 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 
193 	hfs = (struct hfs_mdb *) buf;
194 	if (hfs->signature[0] != 'B' || hfs->signature[1] != 'D')
195 		goto checkplus;
196 
197 	/* it may be just a hfs wrapper for hfs+ */
198 	if (hfs->embed_sig[0] == 'H' && hfs->embed_sig[1] == '+') {
199 		alloc_block_size = be32_to_cpu(hfs->al_blk_size);
200 		dbg("alloc_block_size 0x%x", alloc_block_size);
201 
202 		alloc_first_block = be16_to_cpu(hfs->al_bl_st);
203 		dbg("alloc_first_block 0x%x", alloc_first_block);
204 
205 		embed_first_block = be16_to_cpu(hfs->embed_startblock);
206 		dbg("embed_first_block 0x%x", 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", (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 	hfs_set_uuid(id, hfs->finder_info.id);
224 //	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
225 	IF_FEATURE_BLKID_TYPE(id->type = "hfs";)
226 
227 	return 0;
228 
229  checkplus:
230 	hfsplus = (struct hfsplus_vol_header *) buf;
231 	if (hfs->signature[0] == 'H')
232 		if (hfs->signature[1] == '+' || hfs->signature[1] == 'X')
233 			goto hfsplus;
234 	return -1;
235 
236  hfsplus:
237 	hfs_set_uuid(id, hfsplus->finder_info.id);
238 
239 	blocksize = be32_to_cpu(hfsplus->blocksize);
240 	dbg("blocksize %u", blocksize);
241 
242 	memcpy(extents, hfsplus->cat_file.extents, sizeof(extents));
243 	cat_block = be32_to_cpu(extents[0].start_block);
244 	dbg("catalog start block 0x%x", cat_block);
245 
246 	buf = volume_id_get_buffer(id, off + (cat_block * blocksize), 0x2000);
247 	if (buf == NULL)
248 		goto found;
249 
250 	bnode = (struct hfsplus_bheader_record *)
251 		&buf[sizeof(struct hfsplus_bnode_descriptor)];
252 
253 	leaf_node_head = be32_to_cpu(bnode->leaf_head);
254 	dbg("catalog leaf node 0x%x", leaf_node_head);
255 
256 	leaf_node_size = be16_to_cpu(bnode->node_size);
257 	dbg("leaf node size 0x%x", leaf_node_size);
258 
259 	leaf_node_count = be32_to_cpu(bnode->leaf_count);
260 	dbg("leaf node count 0x%x", leaf_node_count);
261 	if (leaf_node_count == 0)
262 		goto found;
263 
264 	leaf_block = (leaf_node_head * leaf_node_size) / blocksize;
265 
266 	/* get physical location */
267 	for (ext = 0; ext < HFSPLUS_EXTENT_COUNT; ext++) {
268 		ext_block_start = be32_to_cpu(extents[ext].start_block);
269 		ext_block_count = be32_to_cpu(extents[ext].block_count);
270 		dbg("extent start block 0x%x, count 0x%x", ext_block_start, ext_block_count);
271 
272 		if (ext_block_count == 0)
273 			goto found;
274 
275 		/* this is our extent */
276 		if (leaf_block < ext_block_count)
277 			break;
278 
279 		leaf_block -= ext_block_count;
280 	}
281 	if (ext == HFSPLUS_EXTENT_COUNT)
282 		goto found;
283 	dbg("found block in extent %i", ext);
284 
285 	leaf_off = (ext_block_start + leaf_block) * blocksize;
286 
287 	buf = volume_id_get_buffer(id, off + leaf_off, leaf_node_size);
288 	if (buf == NULL)
289 		goto found;
290 
291 	descr = (struct hfsplus_bnode_descriptor *) buf;
292 	dbg("descriptor type 0x%x", descr->type);
293 
294 	record_count = be16_to_cpu(descr->num_recs);
295 	dbg("number of records %u", record_count);
296 	if (record_count == 0)
297 		goto found;
298 
299 	if (descr->type != HFS_NODE_LEAF)
300 		goto found;
301 
302 	key = (struct hfsplus_catalog_key *)
303 		&buf[sizeof(struct hfsplus_bnode_descriptor)];
304 
305 	dbg("parent id 0x%x", be32_to_cpu(key->parent_id));
306 	if (key->parent_id != cpu_to_be32(HFSPLUS_POR_CNID))
307 		goto found;
308 
309 	label_len = be16_to_cpu(key->unicode_len) * 2;
310 	dbg("label unicode16 len %i", label_len);
311 //	volume_id_set_label_raw(id, key->unicode, label_len);
312 	volume_id_set_label_unicode16(id, key->unicode, BE, label_len);
313 
314  found:
315 //	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
316 	IF_FEATURE_BLKID_TYPE(id->type = "hfsplus";)
317 
318 	return 0;
319 }
320