busybox/util-linux/volume_id/unused_msdos.c
Denys Vlasenko f560422fa0 Big cleanup in config help and description
Redundant help texts (one which only repeats the description)
are deleted.

Descriptions and help texts are trimmed.

Some config options are moved, even across menus.

No config option _names_ are changed.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-01-10 14:58:54 +01:00

203 lines
5.3 KiB
C

/*
* 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
*/
//kbuild:### lib-$(CONFIG_FEATURE_VOLUMEID_MSDOS) += msdos.o
//config:### config FEATURE_VOLUMEID_MSDOS
//config:### bool "msdos filesystem"
//config:### default y
//config:### depends on VOLUMEID
#include "volume_id_internal.h"
struct msdos_partition_entry {
uint8_t boot_ind;
uint8_t head;
uint8_t sector;
uint8_t cyl;
uint8_t sys_ind;
uint8_t end_head;
uint8_t end_sector;
uint8_t end_cyl;
uint32_t start_sect;
uint32_t nr_sects;
} PACKED;
#define MSDOS_PARTTABLE_OFFSET 0x1be
#define MSDOS_SIG_OFF 0x1fe
#define BSIZE 0x200
#define DOS_EXTENDED_PARTITION 0x05
#define LINUX_EXTENDED_PARTITION 0x85
#define WIN98_EXTENDED_PARTITION 0x0f
#define LINUX_RAID_PARTITION 0xfd
#define is_extended(type) \
(type == DOS_EXTENDED_PARTITION || \
type == WIN98_EXTENDED_PARTITION || \
type == LINUX_EXTENDED_PARTITION)
#define is_raid(type) \
(type == LINUX_RAID_PARTITION)
int FAST_FUNC volume_id_probe_msdos_part_table(struct volume_id *id, uint64_t off)
{
const uint8_t *buf;
int i;
uint64_t poff;
uint64_t plen;
uint64_t extended = 0;
uint64_t current;
uint64_t next;
int limit;
int empty = 1;
struct msdos_partition_entry *part;
struct volume_id_partition *p;
dbg("probing at offset 0x%llx", (unsigned long long) off);
buf = volume_id_get_buffer(id, off, 0x200);
if (buf == NULL)
return -1;
if (buf[MSDOS_SIG_OFF] != 0x55 || buf[MSDOS_SIG_OFF + 1] != 0xaa)
return -1;
/* check flags on all entries for a valid partition table */
part = (struct msdos_partition_entry*) &buf[MSDOS_PARTTABLE_OFFSET];
for (i = 0; i < 4; i++) {
if (part[i].boot_ind != 0
&& part[i].boot_ind != 0x80
) {
return -1;
}
if (part[i].nr_sects != 0)
empty = 0;
}
if (empty == 1)
return -1;
if (id->partitions != NULL)
free(id->partitions);
id->partitions = xzalloc(VOLUME_ID_PARTITIONS_MAX *
sizeof(struct volume_id_partition));
for (i = 0; i < 4; i++) {
poff = (uint64_t) le32_to_cpu(part[i].start_sect) * BSIZE;
plen = (uint64_t) le32_to_cpu(part[i].nr_sects) * BSIZE;
if (plen == 0)
continue;
p = &id->partitions[i];
// p->pt_type_raw = part[i].sys_ind;
if (is_extended(part[i].sys_ind)) {
dbg("found extended partition at 0x%llx", (unsigned long long) poff);
// volume_id_set_usage_part(p, VOLUME_ID_PARTITIONTABLE);
// p->type = "msdos_extended_partition";
if (extended == 0)
extended = off + poff;
} else {
dbg("found 0x%x data partition at 0x%llx, len 0x%llx",
part[i].sys_ind, (unsigned long long) poff, (unsigned long long) plen);
// if (is_raid(part[i].sys_ind))
// volume_id_set_usage_part(p, VOLUME_ID_RAID);
// else
// volume_id_set_usage_part(p, VOLUME_ID_UNPROBED);
}
// p->pt_off = off + poff;
// p->pt_len = plen;
id->partition_count = i+1;
}
next = extended;
current = extended;
limit = 50;
/* follow extended partition chain and add data partitions */
while (next != 0) {
if (limit-- == 0) {
dbg("extended chain limit reached");
break;
}
buf = volume_id_get_buffer(id, current, 0x200);
if (buf == NULL)
break;
part = (struct msdos_partition_entry*) &buf[MSDOS_PARTTABLE_OFFSET];
if (buf[MSDOS_SIG_OFF] != 0x55 || buf[MSDOS_SIG_OFF + 1] != 0xaa)
break;
next = 0;
for (i = 0; i < 4; i++) {
poff = (uint64_t) le32_to_cpu(part[i].start_sect) * BSIZE;
plen = (uint64_t) le32_to_cpu(part[i].nr_sects) * BSIZE;
if (plen == 0)
continue;
if (is_extended(part[i].sys_ind)) {
dbg("found extended partition at 0x%llx", (unsigned long long) poff);
if (next == 0)
next = extended + poff;
} else {
dbg("found 0x%x data partition at 0x%llx, len 0x%llx",
part[i].sys_ind, (unsigned long long) poff, (unsigned long long) plen);
/* we always start at the 5th entry */
// while (id->partition_count < 4)
// volume_id_set_usage_part(&id->partitions[id->partition_count++], VOLUME_ID_UNUSED);
if (id->partition_count < 4)
id->partition_count = 4;
// p = &id->partitions[id->partition_count];
// if (is_raid(part[i].sys_ind))
// volume_id_set_usage_part(p, VOLUME_ID_RAID);
// else
// volume_id_set_usage_part(p, VOLUME_ID_UNPROBED);
// p->pt_off = current + poff;
// p->pt_len = plen;
id->partition_count++;
// p->pt_type_raw = part[i].sys_ind;
if (id->partition_count >= VOLUME_ID_PARTITIONS_MAX) {
dbg("too many partitions");
next = 0;
}
}
}
current = next;
}
// volume_id_set_usage(id, VOLUME_ID_PARTITIONTABLE);
// id->type = "msdos_partition_table";
return 0;
}