1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
libparted - a library for manipulating disk partitions
Copyright (C) 2018-2023 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <parted/parted.h>
/* Read bytes using ped_geometry_read() function */
static int read_bytes (const PedGeometry* geom, void* buffer, PedSector offset, PedSector count)
{
char* sector_buffer;
PedSector sector_offset, sector_count, buffer_offset;
sector_offset = offset / geom->dev->sector_size;
sector_count = (offset + count + geom->dev->sector_size - 1) / geom->dev->sector_size - sector_offset;
buffer_offset = offset - sector_offset * geom->dev->sector_size;
sector_buffer = alloca (sector_count * geom->dev->sector_size);
if (!ped_geometry_read (geom, sector_buffer, sector_offset, sector_count))
return 0;
memcpy (buffer, sector_buffer + buffer_offset, count);
return 1;
}
/* Scan VSR and check for UDF VSD */
static int check_vrs (const PedGeometry* geom, unsigned int vsdsize)
{
PedSector block;
PedSector offset;
unsigned char ident[5];
/* Check only first 64 blocks, but theoretically standard does not define upper limit */
for (block = 0; block < 64; block++) {
/* VRS starts at fixed offset 32kB, it is independent of block size or vsd size */
offset = 32768 + block * vsdsize;
/* Read VSD identifier, it is at offset 1 */
if (!read_bytes (geom, ident, offset + 1, 5))
return 0;
/* Check for UDF identifier */
if (memcmp (ident, "NSR02", 5) == 0 ||
memcmp (ident, "NSR03", 5) == 0)
return 1;
/* Unknown VSD identifier means end of VRS */
if (memcmp (ident, "BEA01", 5) != 0 &&
memcmp (ident, "TEA01", 5) != 0 &&
memcmp (ident, "BOOT2", 5) != 0 &&
memcmp (ident, "CD001", 5) != 0 &&
memcmp (ident, "CDW02", 5) != 0)
break;
}
return 0;
}
/* Check for UDF AVDP */
static int check_anchor (const PedGeometry* geom, unsigned int blocksize, int rel_block)
{
PedSector block;
unsigned char tag[16];
/* Negative block means relative to the end of device */
if (rel_block < 0) {
block = geom->length * geom->dev->sector_size / blocksize;
if (block <= (PedSector)(-rel_block))
return 0;
block -= (PedSector)(-rel_block);
if (block < 257)
return 0;
} else {
block = rel_block;
}
if (!read_bytes (geom, tag, block * blocksize, 16))
return 0;
/* Check for AVDP type (0x0002) */
if (((unsigned short)tag[0] | ((unsigned short)tag[1] << 8)) != 0x0002)
return 0;
/* Check that location stored in AVDP matches */
if (((unsigned long)tag[12] | ((unsigned long)tag[13] << 8) | ((unsigned long)tag[14] << 16) | ((unsigned long)tag[15] << 24)) != block)
return 0;
return 1;
}
/* Detect presence of UDF AVDP */
static int detect_anchor(const PedGeometry* geom, unsigned int blocksize)
{
/* All possible AVDP locations in preferred order */
static int anchors[] = { 256, -257, -1, 512 };
size_t i;
for (i = 0; i < sizeof (anchors)/sizeof (*anchors); i++) {
if (check_anchor (geom, blocksize, anchors[i]))
return 1;
}
return 0;
}
/* Detect UDF filesystem, it must have VRS and AVDP */
static int detect_udf (const PedGeometry* geom)
{
unsigned int blocksize;
/* VSD size is min(2048, UDF block size), check for block sizes <= 2048 */
if (check_vrs (geom, 2048)) {
for (blocksize = 512; blocksize <= 2048; blocksize *= 2) {
if (detect_anchor (geom, blocksize))
return 1;
}
}
/* Check for block sizes larger then 2048, maximal theoretical block size is 32kB */
for (blocksize = 4096; blocksize <= 32768; blocksize *= 2) {
if (!check_vrs (geom, blocksize))
continue;
if (detect_anchor (geom, blocksize))
return 1;
}
return 0;
}
PedGeometry*
udf_probe (PedGeometry* geom)
{
if (!detect_udf (geom))
return NULL;
return ped_geometry_duplicate (geom);
}
static PedFileSystemOps udf_ops = {
probe: udf_probe,
};
static PedFileSystemType udf_type = {
next: NULL,
ops: &udf_ops,
name: "udf",
};
void
ped_file_system_udf_init ()
{
ped_file_system_type_register (&udf_type);
}
void
ped_file_system_udf_done ()
{
ped_file_system_type_unregister (&udf_type);
}
|
