busybox/util-linux/volume_id/udf.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 volume_descriptor {
struct descriptor_tag {
uint16_t id;
uint16_t version;
uint8_t checksum;
uint8_t reserved;
uint16_t serial;
uint16_t crc;
uint16_t crc_len;
uint32_t location;
} __attribute__((__packed__)) tag;
union {
struct anchor_descriptor {
uint32_t length;
uint32_t location;
} __attribute__((__packed__)) anchor;
struct primary_descriptor {
uint32_t seq_num;
uint32_t desc_num;
struct dstring {
uint8_t clen;
uint8_t c[31];
} __attribute__((__packed__)) ident;
} __attribute__((__packed__)) primary;
} __attribute__((__packed__)) type;
} __attribute__((__packed__));
struct volume_structure_descriptor {
uint8_t type;
uint8_t id[5];
uint8_t version;
} __attribute__((__packed__));
#define UDF_VSD_OFFSET 0x8000
int volume_id_probe_udf(struct volume_id *id, uint64_t off)
{
struct volume_descriptor *vd;
struct volume_structure_descriptor *vsd;
unsigned bs;
unsigned b;
unsigned type;
unsigned count;
unsigned loc;
unsigned clen;
dbg("probing at offset 0x%llx", (unsigned long long) off);
vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET, 0x200);
if (vsd == NULL)
return -1;
if (memcmp(vsd->id, "NSR02", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "NSR03", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "BEA01", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "BOOT2", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "CD001", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "CDW02", 5) == 0)
goto blocksize;
if (memcmp(vsd->id, "TEA03", 5) == 0)
goto blocksize;
return -1;
blocksize:
/* search the next VSD to get the logical block size of the volume */
for (bs = 0x800; bs < 0x8000; bs += 0x800) {
vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + bs, 0x800);
if (vsd == NULL)
return -1;
dbg("test for blocksize: 0x%x", bs);
if (vsd->id[0] != '\0')
goto nsr;
}
return -1;
nsr:
/* search the list of VSDs for a NSR descriptor */
for (b = 0; b < 64; b++) {
vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + (b * bs), 0x800);
if (vsd == NULL)
return -1;
dbg("vsd: %c%c%c%c%c",
vsd->id[0], vsd->id[1], vsd->id[2], vsd->id[3], vsd->id[4]);
if (vsd->id[0] == '\0')
return -1;
if (memcmp(vsd->id, "NSR02", 5) == 0)
goto anchor;
if (memcmp(vsd->id, "NSR03", 5) == 0)
goto anchor;
}
return -1;
anchor:
/* read anchor volume descriptor */
vd = volume_id_get_buffer(id, off + (256 * bs), 0x200);
if (vd == NULL)
return -1;
type = le16_to_cpu(vd->tag.id);
if (type != 2) /* TAG_ID_AVDP */
goto found;
/* get desriptor list address and block count */
count = le32_to_cpu(vd->type.anchor.length) / bs;
loc = le32_to_cpu(vd->type.anchor.location);
dbg("0x%x descriptors starting at logical secor 0x%x", count, loc);
/* pick the primary descriptor from the list */
for (b = 0; b < count; b++) {
vd = volume_id_get_buffer(id, off + ((loc + b) * bs), 0x200);
if (vd == NULL)
return -1;
type = le16_to_cpu(vd->tag.id);
dbg("descriptor type %i", type);
/* check validity */
if (type == 0)
goto found;
if (le32_to_cpu(vd->tag.location) != loc + b)
goto found;
if (type == 1) /* TAG_ID_PVD */
goto pvd;
}
goto found;
pvd:
volume_id_set_label_raw(id, &(vd->type.primary.ident.clen), 32);
clen = vd->type.primary.ident.clen;
dbg("label string charsize=%i bit", clen);
if (clen == 8)
volume_id_set_label_string(id, vd->type.primary.ident.c, 31);
else if (clen == 16)
volume_id_set_label_unicode16(id, vd->type.primary.ident.c, BE, 31);
found:
volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
id->type = "udf";
return 0;
}