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/*
* Copyright (C) 2009 Corentin Chary <corentincj@iksaif.net>
*
* 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"
#include "crc32.h"
/*
* struct ubifs_ch - common header node.
* @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
* @crc: CRC-32 checksum of the node header
* @sqnum: sequence number
* @len: full node length
* @node_type: node type
* @group_type: node group type
* @padding: reserved for future, zeroes
*
* Every UBIFS node starts with this common part. If the node has a key, the
* key always goes next.
*/
struct ubifs_ch {
uint32_t magic;
uint32_t crc;
uint64_t sqnum;
uint32_t len;
uint8_t node_type;
uint8_t group_type;
uint8_t padding[2];
} __attribute__ ((packed));
/*
* struct ubifs_sb_node - superblock node.
* @ch: common header
* @padding: reserved for future, zeroes
* @key_hash: type of hash function used in keys
* @key_fmt: format of the key
* @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
* @min_io_size: minimal input/output unit size
* @leb_size: logical eraseblock size in bytes
* @leb_cnt: count of LEBs used by file-system
* @max_leb_cnt: maximum count of LEBs used by file-system
* @max_bud_bytes: maximum amount of data stored in buds
* @log_lebs: log size in logical eraseblocks
* @lpt_lebs: number of LEBs used for lprops table
* @orph_lebs: number of LEBs used for recording orphans
* @jhead_cnt: count of journal heads
* @fanout: tree fanout (max. number of links per indexing node)
* @lsave_cnt: number of LEB numbers in LPT's save table
* @fmt_version: UBIFS on-flash format version
* @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
* @padding1: reserved for future, zeroes
* @rp_uid: reserve pool UID
* @rp_gid: reserve pool GID
* @rp_size: size of the reserved pool in bytes
* @padding2: reserved for future, zeroes
* @time_gran: time granularity in nanoseconds
* @uuid: UUID generated when the file system image was created
* @ro_compat_version: UBIFS R/O compatibility version
*/
struct ubifs_sb_node {
struct ubifs_ch ch;
uint8_t padding[2];
uint8_t key_hash;
uint8_t key_fmt;
uint32_t flags;
uint32_t min_io_size;
uint32_t leb_size;
uint32_t leb_cnt;
uint32_t max_leb_cnt;
uint64_t max_bud_bytes;
uint32_t log_lebs;
uint32_t lpt_lebs;
uint32_t orph_lebs;
uint32_t jhead_cnt;
uint32_t fanout;
uint32_t lsave_cnt;
uint32_t fmt_version;
uint16_t default_compr;
uint8_t padding1[2];
uint32_t rp_uid;
uint32_t rp_gid;
uint64_t rp_size;
uint32_t time_gran;
uint8_t uuid[16];
uint32_t ro_compat_version;
uint8_t padding2[3968];
} __attribute__ ((packed));
static int ubifs_verify_csum(blkid_probe pr, const struct ubifs_sb_node *sb)
{
size_t csummed_offset = offsetof(struct ubifs_ch, sqnum);
uint32_t crc = ul_crc32(~0LL,
(unsigned char *) sb + csummed_offset,
sizeof(*sb) - csummed_offset);
return blkid_probe_verify_csum(pr, crc, le32_to_cpu(sb->ch.crc));
}
static int probe_ubifs(blkid_probe pr, const struct blkid_idmag *mag)
{
const struct ubifs_sb_node *sb;
sb = blkid_probe_get_sb(pr, mag, struct ubifs_sb_node);
if (!sb)
return errno ? -errno : 1;
if (!ubifs_verify_csum(pr, sb))
return 1;
blkid_probe_set_uuid(pr, sb->uuid);
blkid_probe_sprintf_version(pr, "w%dr%d",
le32_to_cpu(sb->fmt_version),
le32_to_cpu(sb->ro_compat_version));
blkid_probe_set_fssize(pr,
(uint64_t) le32_to_cpu(sb->leb_size)
* le32_to_cpu(sb->leb_cnt));
return 0;
}
const struct blkid_idinfo ubifs_idinfo =
{
.name = "ubifs",
.usage = BLKID_USAGE_FILESYSTEM,
.probefunc = probe_ubifs,
.magics =
{
{ .magic = "\x31\x18\x10\x06", .len = 4 },
{ NULL }
}
};
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