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/*
* Copyright (C) 1999 by Andries Brouwer
* Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
* Copyright (C) 2001 by Andreas Dilger
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2008 Karel Zak <kzak@redhat.com>
*
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdint.h>
#include "superblocks.h"
#define LVM1_ID_LEN 128
#define LVM2_ID_LEN 32
struct lvm2_pv_label_header {
/* label_header */
uint8_t id[8]; /* LABELONE */
uint64_t sector_xl; /* Sector number of this label */
uint32_t crc_xl; /* From next field to end of sector */
uint32_t offset_xl; /* Offset from start of struct to contents */
uint8_t type[8]; /* LVM2 001 */
/* pv_header */
uint8_t pv_uuid[LVM2_ID_LEN];
} __attribute__ ((packed));
struct lvm1_pv_label_header {
uint8_t id[2]; /* HM */
uint16_t version; /* version 1 or 2 */
uint32_t _notused[10]; /* lvm1 internals */
uint8_t pv_uuid[LVM1_ID_LEN];
} __attribute__ ((packed));
#define LVM2_LABEL_SIZE 512
static unsigned int lvm2_calc_crc(const void *buf, unsigned int size)
{
static const unsigned int crctab[] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
};
unsigned int i, crc = 0xf597a6cf;
const uint8_t *data = (const uint8_t *) buf;
for (i = 0; i < size; i++) {
crc ^= *data++;
crc = (crc >> 4) ^ crctab[crc & 0xf];
crc = (crc >> 4) ^ crctab[crc & 0xf];
}
return crc;
}
/* Length of real UUID is always LVM2_ID_LEN */
static void format_lvm_uuid(char *dst_uuid, char *src_uuid)
{
unsigned int i, b;
for (i = 0, b = 1; i < LVM2_ID_LEN; i++, b <<= 1) {
if (b & 0x4444440)
*dst_uuid++ = '-';
*dst_uuid++ = *src_uuid++;
}
*dst_uuid = '\0';
}
static int probe_lvm2(blkid_probe pr, const struct blkid_idmag *mag)
{
int sector = mag->kboff << 1;
struct lvm2_pv_label_header *label;
char uuid[LVM2_ID_LEN + 7];
unsigned char *buf;
buf = blkid_probe_get_buffer(pr,
mag->kboff << 10,
512 + sizeof(struct lvm2_pv_label_header));
if (!buf)
return -1;
/* buf is at 0k or 1k offset; find label inside */
if (memcmp(buf, "LABELONE", 8) == 0) {
label = (struct lvm2_pv_label_header *) buf;
} else if (memcmp(buf + 512, "LABELONE", 8) == 0) {
label = (struct lvm2_pv_label_header *)(buf + 512);
sector++;
} else {
return 1;
}
if (le64_to_cpu(label->sector_xl) != (unsigned) sector)
return 1;
if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE -
((char *) &label->offset_xl - (char *) label)) !=
le32_to_cpu(label->crc_xl)) {
DBG(DEBUG_PROBE,
printf("LVM2: label checksum incorrect at sector %d\n",
sector));
return 1;
}
format_lvm_uuid(uuid, (char *) label->pv_uuid);
blkid_probe_sprintf_uuid(pr, label->pv_uuid, sizeof(label->pv_uuid),
"%s", uuid);
/* the mag->magic is the same string as label->type,
* but zero terminated */
blkid_probe_set_version(pr, mag->magic);
/* LVM (pvcreate) wipes begin of the device -- let's remember this
* to resolve conflicts bettween LVM and partition tables, ...
*/
blkid_probe_set_wiper(pr, 0, 8 * 1024);
return 0;
}
static int probe_lvm1(blkid_probe pr, const struct blkid_idmag *mag)
{
struct lvm1_pv_label_header *label;
char uuid[LVM2_ID_LEN + 7];
unsigned int version;
label = blkid_probe_get_sb(pr, mag, struct lvm1_pv_label_header);
if (!label)
return -1;
version = le16_to_cpu(label->version);
if (version != 1 && version != 2)
return 1;
format_lvm_uuid(uuid, (char *) label->pv_uuid);
blkid_probe_sprintf_uuid(pr, label->pv_uuid, sizeof(label->pv_uuid),
"%s", uuid);
return 0;
}
/* NOTE: the original libblkid uses "lvm2pv" as a name */
const struct blkid_idinfo lvm2_idinfo =
{
.name = "LVM2_member",
.usage = BLKID_USAGE_RAID,
.probefunc = probe_lvm2,
.magics =
{
{ .magic = "LVM2 001", .len = 8, .sboff = 0x218 },
{ .magic = "LVM2 001", .len = 8, .sboff = 0x018 },
{ .magic = "LVM2 001", .len = 8, .kboff = 1, .sboff = 0x018 },
{ .magic = "LVM2 001", .len = 8, .kboff = 1, .sboff = 0x218 },
{ NULL }
}
};
const struct blkid_idinfo lvm1_idinfo =
{
.name = "LVM1_member",
.usage = BLKID_USAGE_RAID,
.probefunc = probe_lvm1,
.magics =
{
{ .magic = "HM", .len = 2 },
{ NULL }
}
};
const struct blkid_idinfo snapcow_idinfo =
{
.name = "DM_snapshot_cow",
.usage = BLKID_USAGE_OTHER,
.magics =
{
{ .magic = "SnAp", .len = 4 },
{ NULL }
}
};
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