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_UDF
21 //config: bool "udf filesystem"
22 //config: default y
23 //config: depends on VOLUMEID
24
25 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_UDF) += udf.o
26
27 #include "volume_id_internal.h"
28
29 struct volume_descriptor {
30 struct descriptor_tag {
31 uint16_t id;
32 uint16_t version;
33 uint8_t checksum;
34 uint8_t reserved;
35 uint16_t serial;
36 uint16_t crc;
37 uint16_t crc_len;
38 uint32_t location;
39 } PACKED tag;
40 union {
41 struct anchor_descriptor {
42 uint32_t length;
43 uint32_t location;
44 } PACKED anchor;
45 struct primary_descriptor {
46 uint32_t seq_num;
47 uint32_t desc_num;
48 struct dstring {
49 uint8_t clen;
50 uint8_t c[31];
51 } PACKED ident;
52 } PACKED primary;
53 } PACKED type;
54 } PACKED;
55
56 struct volume_structure_descriptor {
57 uint8_t type;
58 uint8_t id[5];
59 uint8_t version;
60 } PACKED;
61
62 #define UDF_VSD_OFFSET 0x8000
63
volume_id_probe_udf(struct volume_id * id)64 int FAST_FUNC volume_id_probe_udf(struct volume_id *id /*,uint64_t off*/)
65 {
66 #define off ((uint64_t)0)
67 struct volume_descriptor *vd;
68 struct volume_structure_descriptor *vsd;
69 unsigned bs;
70 unsigned b;
71 unsigned type;
72 unsigned count;
73 unsigned loc;
74 unsigned clen;
75
76 dbg("probing at offset 0x%llx", (unsigned long long) off);
77
78 vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET, 0x200);
79 if (vsd == NULL)
80 return -1;
81
82 if (memcmp(vsd->id, "NSR02", 5) == 0)
83 goto blocksize;
84 if (memcmp(vsd->id, "NSR03", 5) == 0)
85 goto blocksize;
86 if (memcmp(vsd->id, "BEA01", 5) == 0)
87 goto blocksize;
88 if (memcmp(vsd->id, "BOOT2", 5) == 0)
89 goto blocksize;
90 if (memcmp(vsd->id, "CD001", 5) == 0)
91 goto blocksize;
92 if (memcmp(vsd->id, "CDW02", 5) == 0)
93 goto blocksize;
94 if (memcmp(vsd->id, "TEA03", 5) == 0)
95 goto blocksize;
96 return -1;
97
98 blocksize:
99 /* search the next VSD to get the logical block size of the volume */
100 for (bs = 0x800; bs < 0x8000; bs += 0x800) {
101 vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + bs, 0x800);
102 if (vsd == NULL)
103 return -1;
104 dbg("test for blocksize: 0x%x", bs);
105 if (vsd->id[0] != '\0')
106 goto nsr;
107 }
108 return -1;
109
110 nsr:
111 /* search the list of VSDs for a NSR descriptor */
112 for (b = 0; b < 64; b++) {
113 vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + (b * bs), 0x800);
114 if (vsd == NULL)
115 return -1;
116
117 dbg("vsd: %c%c%c%c%c",
118 vsd->id[0], vsd->id[1], vsd->id[2], vsd->id[3], vsd->id[4]);
119
120 if (vsd->id[0] == '\0')
121 return -1;
122 if (memcmp(vsd->id, "NSR02", 5) == 0)
123 goto anchor;
124 if (memcmp(vsd->id, "NSR03", 5) == 0)
125 goto anchor;
126 }
127 return -1;
128
129 anchor:
130 /* read anchor volume descriptor */
131 vd = volume_id_get_buffer(id, off + (256 * bs), 0x200);
132 if (vd == NULL)
133 return -1;
134
135 type = le16_to_cpu(vd->tag.id);
136 if (type != 2) /* TAG_ID_AVDP */
137 goto found;
138
139 /* get descriptor list address and block count */
140 count = le32_to_cpu(vd->type.anchor.length) / bs;
141 loc = le32_to_cpu(vd->type.anchor.location);
142 dbg("0x%x descriptors starting at logical secor 0x%x", count, loc);
143
144 /* pick the primary descriptor from the list */
145 for (b = 0; b < count; b++) {
146 vd = volume_id_get_buffer(id, off + ((loc + b) * bs), 0x200);
147 if (vd == NULL)
148 return -1;
149
150 type = le16_to_cpu(vd->tag.id);
151 dbg("descriptor type %i", type);
152
153 /* check validity */
154 if (type == 0)
155 goto found;
156 if (le32_to_cpu(vd->tag.location) != loc + b)
157 goto found;
158
159 if (type == 1) /* TAG_ID_PVD */
160 goto pvd;
161 }
162 goto found;
163
164 pvd:
165 // volume_id_set_label_raw(id, &(vd->type.primary.ident.clen), 32);
166
167 clen = vd->type.primary.ident.clen;
168 dbg("label string charsize=%i bit", clen);
169 if (clen == 8)
170 volume_id_set_label_string(id, vd->type.primary.ident.c, 31);
171 else if (clen == 16)
172 volume_id_set_label_unicode16(id, vd->type.primary.ident.c, BE, 31);
173
174 found:
175 // volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
176 IF_FEATURE_BLKID_TYPE(id->type = "udf";)
177 return 0;
178 }
179