busybox/util-linux/volume_id/ntfs.c
Denis Vlasenko 28ea4298e3 volume_id: abort early on read failures.
should help with probing missing fdd's
2009-02-15 05:51:19 +00:00

195 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
*/
#include "volume_id_internal.h"
struct ntfs_super_block {
uint8_t jump[3];
uint8_t oem_id[8];
uint16_t bytes_per_sector;
uint8_t sectors_per_cluster;
uint16_t reserved_sectors;
uint8_t fats;
uint16_t root_entries;
uint16_t sectors;
uint8_t media_type;
uint16_t sectors_per_fat;
uint16_t sectors_per_track;
uint16_t heads;
uint32_t hidden_sectors;
uint32_t large_sectors;
uint16_t unused[2];
uint64_t number_of_sectors;
uint64_t mft_cluster_location;
uint64_t mft_mirror_cluster_location;
int8_t cluster_per_mft_record;
uint8_t reserved1[3];
int8_t cluster_per_index_record;
uint8_t reserved2[3];
uint8_t volume_serial[8];
uint16_t checksum;
} __attribute__((__packed__));
struct master_file_table_record {
uint8_t magic[4];
uint16_t usa_ofs;
uint16_t usa_count;
uint64_t lsn;
uint16_t sequence_number;
uint16_t link_count;
uint16_t attrs_offset;
uint16_t flags;
uint32_t bytes_in_use;
uint32_t bytes_allocated;
} __attribute__((__packed__));
struct file_attribute {
uint32_t type;
uint32_t len;
uint8_t non_resident;
uint8_t name_len;
uint16_t name_offset;
uint16_t flags;
uint16_t instance;
uint32_t value_len;
uint16_t value_offset;
} __attribute__((__packed__));
struct volume_info {
uint64_t reserved;
uint8_t major_ver;
uint8_t minor_ver;
} __attribute__((__packed__));
#define MFT_RECORD_VOLUME 3
#define MFT_RECORD_ATTR_VOLUME_NAME 0x60
#define MFT_RECORD_ATTR_VOLUME_INFO 0x70
#define MFT_RECORD_ATTR_OBJECT_ID 0x40
#define MFT_RECORD_ATTR_END 0xffffffffu
int volume_id_probe_ntfs(struct volume_id *id /*,uint64_t off*/)
{
#define off ((uint64_t)0)
unsigned sector_size;
unsigned cluster_size;
uint64_t mft_cluster;
uint64_t mft_off;
unsigned mft_record_size;
unsigned attr_type;
unsigned attr_off;
unsigned attr_len;
unsigned val_off;
unsigned val_len;
struct master_file_table_record *mftr;
struct ntfs_super_block *ns;
const uint8_t *buf;
const uint8_t *val;
dbg("probing at offset 0x%llx", (unsigned long long) off);
ns = volume_id_get_buffer(id, off, 0x200);
if (ns == NULL)
return -1;
if (memcmp(ns->oem_id, "NTFS", 4) != 0)
return -1;
volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
sector_size = le16_to_cpu(ns->bytes_per_sector);
cluster_size = ns->sectors_per_cluster * sector_size;
mft_cluster = le64_to_cpu(ns->mft_cluster_location);
mft_off = mft_cluster * cluster_size;
if (ns->cluster_per_mft_record < 0)
/* size = -log2(mft_record_size); normally 1024 Bytes */
mft_record_size = 1 << -ns->cluster_per_mft_record;
else
mft_record_size = ns->cluster_per_mft_record * cluster_size;
dbg("sectorsize 0x%x", sector_size);
dbg("clustersize 0x%x", cluster_size);
dbg("mftcluster %llu", (unsigned long long) mft_cluster);
dbg("mftoffset 0x%llx", (unsigned long long) mft_off);
dbg("cluster per mft_record %i", ns->cluster_per_mft_record);
dbg("mft record size %i", mft_record_size);
buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
mft_record_size);
if (buf == NULL)
goto found;
mftr = (struct master_file_table_record*) buf;
dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
if (memcmp(mftr->magic, "FILE", 4) != 0)
goto found;
attr_off = le16_to_cpu(mftr->attrs_offset);
dbg("file $Volume's attributes are at offset %i", attr_off);
while (1) {
struct file_attribute *attr;
attr = (struct file_attribute*) &buf[attr_off];
attr_type = le32_to_cpu(attr->type);
attr_len = le16_to_cpu(attr->len);
val_off = le16_to_cpu(attr->value_offset);
val_len = le32_to_cpu(attr->value_len);
attr_off += attr_len;
if (attr_len == 0)
break;
if (attr_off >= mft_record_size)
break;
if (attr_type == MFT_RECORD_ATTR_END)
break;
dbg("found attribute type 0x%x, len %i, at offset %i",
attr_type, attr_len, attr_off);
// if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
// struct volume_info *info;
// dbg("found info, len %i", val_len);
// info = (struct volume_info*) (((uint8_t *) attr) + val_off);
// snprintf(id->type_version, sizeof(id->type_version)-1,
// "%u.%u", info->major_ver, info->minor_ver);
// }
if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
dbg("found label, len %i", val_len);
if (val_len > VOLUME_ID_LABEL_SIZE)
val_len = VOLUME_ID_LABEL_SIZE;
val = ((uint8_t *) attr) + val_off;
// volume_id_set_label_raw(id, val, val_len);
volume_id_set_label_unicode16(id, val, LE, val_len);
}
}
found:
// volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
// id->type = "ntfs";
return 0;
}