util-linux/volume_id/ntfs.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation; either
   9  *      version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *      This library is distributed in the hope that it will be useful,
  12  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *      Lesser General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU Lesser General Public
  17  *      License along with this library; if not, write to the Free Software
  18  *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_NTFS) += ntfs.o
  22
  23 //config:config FEATURE_VOLUMEID_NTFS
  24 //config:       bool "ntfs filesystem"
  25 //config:       default y
  26 //config:       depends on VOLUMEID
  27
  28 #include "volume_id_internal.h"
  29
  30 struct ntfs_super_block {
  31         uint8_t         jump[3];
  32         uint8_t         oem_id[8];
  33         uint16_t        bytes_per_sector;
  34         uint8_t         sectors_per_cluster;
  35         uint16_t        reserved_sectors;
  36         uint8_t         fats;
  37         uint16_t        root_entries;
  38         uint16_t        sectors;
  39         uint8_t         media_type;
  40         uint16_t        sectors_per_fat;
  41         uint16_t        sectors_per_track;
  42         uint16_t        heads;
  43         uint32_t        hidden_sectors;
  44         uint32_t        large_sectors;
  45         uint16_t        unused[2];
  46         uint64_t        number_of_sectors;
  47         uint64_t        mft_cluster_location;
  48         uint64_t        mft_mirror_cluster_location;
  49         int8_t          cluster_per_mft_record;
  50         uint8_t         reserved1[3];
  51         int8_t          cluster_per_index_record;
  52         uint8_t         reserved2[3];
  53         uint8_t         volume_serial[8];
  54         uint16_t        checksum;
  55 } PACKED;
  56
  57 struct master_file_table_record {
  58         uint8_t         magic[4];
  59         uint16_t        usa_ofs;
  60         uint16_t        usa_count;
  61         uint64_t        lsn;
  62         uint16_t        sequence_number;
  63         uint16_t        link_count;
  64         uint16_t        attrs_offset;
  65         uint16_t        flags;
  66         uint32_t        bytes_in_use;
  67         uint32_t        bytes_allocated;
  68 } PACKED;
  69
  70 struct file_attribute {
  71         uint32_t        type;
  72         uint32_t        len;
  73         uint8_t         non_resident;
  74         uint8_t         name_len;
  75         uint16_t        name_offset;
  76         uint16_t        flags;
  77         uint16_t        instance;
  78         uint32_t        value_len;
  79         uint16_t        value_offset;
  80 } PACKED;
  81
  82 struct volume_info {
  83         uint64_t        reserved;
  84         uint8_t         major_ver;
  85         uint8_t         minor_ver;
  86 } PACKED;
  87
  88 #define MFT_RECORD_VOLUME                       3
  89 #define MFT_RECORD_ATTR_VOLUME_NAME             0x60
  90 #define MFT_RECORD_ATTR_VOLUME_INFO             0x70
  91 #define MFT_RECORD_ATTR_OBJECT_ID               0x40
  92 #define MFT_RECORD_ATTR_END                     0xffffffffu
  93
  94 int FAST_FUNC volume_id_probe_ntfs(struct volume_id *id /*,uint64_t off*/)
  95 {
  96 #define off ((uint64_t)0)
  97         unsigned sector_size;
  98         unsigned cluster_size;
  99         uint64_t mft_cluster;
 100         uint64_t mft_off;
 101         unsigned mft_record_size;
 102         unsigned attr_type;
 103         unsigned attr_off;
 104         unsigned attr_len;
 105         unsigned val_off;
 106         unsigned val_len;
 107         struct master_file_table_record *mftr;
 108         struct ntfs_super_block *ns;
 109         const uint8_t *buf;
 110         const uint8_t *val;
 111
 112         dbg("probing at offset 0x%llx", (unsigned long long) off);
 113
 114         ns = volume_id_get_buffer(id, off, 0x200);
 115         if (ns == NULL)
 116                 return -1;
 117
 118         if (memcmp(ns->oem_id, "NTFS", 4) != 0)
 119                 return -1;
 120
 121         volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
 122
 123         sector_size = le16_to_cpu(ns->bytes_per_sector);
 124         cluster_size = ns->sectors_per_cluster * sector_size;
 125         mft_cluster = le64_to_cpu(ns->mft_cluster_location);
 126         mft_off = mft_cluster * cluster_size;
 127
 128         if (ns->cluster_per_mft_record < 0)
 129                 /* size = -log2(mft_record_size); normally 1024 Bytes */
 130                 mft_record_size = 1 << -ns->cluster_per_mft_record;
 131         else
 132                 mft_record_size = ns->cluster_per_mft_record * cluster_size;
 133
 134         dbg("sectorsize  0x%x", sector_size);
 135         dbg("clustersize 0x%x", cluster_size);
 136         dbg("mftcluster  %llu", (unsigned long long) mft_cluster);
 137         dbg("mftoffset  0x%llx", (unsigned long long) mft_off);
 138         dbg("cluster per mft_record  %i", ns->cluster_per_mft_record);
 139         dbg("mft record size  %i", mft_record_size);
 140
 141         buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
 142                         mft_record_size);
 143         if (buf == NULL)
 144                 goto found;
 145
 146         mftr = (struct master_file_table_record*) buf;
 147
 148         dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
 149         if (memcmp(mftr->magic, "FILE", 4) != 0)
 150                 goto found;
 151
 152         attr_off = le16_to_cpu(mftr->attrs_offset);
 153         dbg("file $Volume's attributes are at offset %i", attr_off);
 154
 155         while (1) {
 156                 struct file_attribute *attr;
 157
 158                 attr = (struct file_attribute*) &buf[attr_off];
 159                 attr_type = le32_to_cpu(attr->type);
 160                 attr_len = le32_to_cpu(attr->len);
 161                 val_off = le16_to_cpu(attr->value_offset);
 162                 val_len = le32_to_cpu(attr->value_len);
 163                 attr_off += attr_len;
 164
 165                 if (attr_len == 0)
 166                         break;
 167
 168                 if (attr_off >= mft_record_size)
 169                         break;
 170
 171                 if (attr_type == MFT_RECORD_ATTR_END)
 172                         break;
 173
 174                 dbg("found attribute type 0x%x, len %i, at offset %i",
 175                         attr_type, attr_len, attr_off);
 176
 177 //              if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
 178 //                      struct volume_info *info;
 179 //                      dbg("found info, len %i", val_len);
 180 //                      info = (struct volume_info*) (((uint8_t *) attr) + val_off);
 181 //                      snprintf(id->type_version, sizeof(id->type_version)-1,
 182 //                               "%u.%u", info->major_ver, info->minor_ver);
 183 //              }
 184
 185                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 186                         dbg("found label, len %i", val_len);
 187                         if (val_len > VOLUME_ID_LABEL_SIZE)
 188                                 val_len = VOLUME_ID_LABEL_SIZE;
 189
 190                         val = ((uint8_t *) attr) + val_off;
 191 //                      volume_id_set_label_raw(id, val, val_len);
 192                         volume_id_set_label_unicode16(id, val, LE, val_len);
 193                 }
 194         }
 195
 196  found:
 197 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 198         IF_FEATURE_BLKID_TYPE(id->type = "ntfs";)
 199
 200         return 0;
 201 }