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:
  24 //config:config FEATURE_VOLUMEID_NTFS
  25 //config:       bool "ntfs filesystem"
  26 //config:       default y
  27 //config:       depends on VOLUMEID
  28 //config:       help
  29 //config:         TODO
  30 //config:
  31
  32 #include "volume_id_internal.h"
  33
  34 struct ntfs_super_block {
  35         uint8_t         jump[3];
  36         uint8_t         oem_id[8];
  37         uint16_t        bytes_per_sector;
  38         uint8_t         sectors_per_cluster;
  39         uint16_t        reserved_sectors;
  40         uint8_t         fats;
  41         uint16_t        root_entries;
  42         uint16_t        sectors;
  43         uint8_t         media_type;
  44         uint16_t        sectors_per_fat;
  45         uint16_t        sectors_per_track;
  46         uint16_t        heads;
  47         uint32_t        hidden_sectors;
  48         uint32_t        large_sectors;
  49         uint16_t        unused[2];
  50         uint64_t        number_of_sectors;
  51         uint64_t        mft_cluster_location;
  52         uint64_t        mft_mirror_cluster_location;
  53         int8_t          cluster_per_mft_record;
  54         uint8_t         reserved1[3];
  55         int8_t          cluster_per_index_record;
  56         uint8_t         reserved2[3];
  57         uint8_t         volume_serial[8];
  58         uint16_t        checksum;
  59 } PACKED;
  60
  61 struct master_file_table_record {
  62         uint8_t         magic[4];
  63         uint16_t        usa_ofs;
  64         uint16_t        usa_count;
  65         uint64_t        lsn;
  66         uint16_t        sequence_number;
  67         uint16_t        link_count;
  68         uint16_t        attrs_offset;
  69         uint16_t        flags;
  70         uint32_t        bytes_in_use;
  71         uint32_t        bytes_allocated;
  72 } PACKED;
  73
  74 struct file_attribute {
  75         uint32_t        type;
  76         uint32_t        len;
  77         uint8_t         non_resident;
  78         uint8_t         name_len;
  79         uint16_t        name_offset;
  80         uint16_t        flags;
  81         uint16_t        instance;
  82         uint32_t        value_len;
  83         uint16_t        value_offset;
  84 } PACKED;
  85
  86 struct volume_info {
  87         uint64_t        reserved;
  88         uint8_t         major_ver;
  89         uint8_t         minor_ver;
  90 } PACKED;
  91
  92 #define MFT_RECORD_VOLUME                       3
  93 #define MFT_RECORD_ATTR_VOLUME_NAME             0x60
  94 #define MFT_RECORD_ATTR_VOLUME_INFO             0x70
  95 #define MFT_RECORD_ATTR_OBJECT_ID               0x40
  96 #define MFT_RECORD_ATTR_END                     0xffffffffu
  97
  98 int FAST_FUNC volume_id_probe_ntfs(struct volume_id *id /*,uint64_t off*/)
  99 {
 100 #define off ((uint64_t)0)
 101         unsigned sector_size;
 102         unsigned cluster_size;
 103         uint64_t mft_cluster;
 104         uint64_t mft_off;
 105         unsigned mft_record_size;
 106         unsigned attr_type;
 107         unsigned attr_off;
 108         unsigned attr_len;
 109         unsigned val_off;
 110         unsigned val_len;
 111         struct master_file_table_record *mftr;
 112         struct ntfs_super_block *ns;
 113         const uint8_t *buf;
 114         const uint8_t *val;
 115
 116         dbg("probing at offset 0x%llx", (unsigned long long) off);
 117
 118         ns = volume_id_get_buffer(id, off, 0x200);
 119         if (ns == NULL)
 120                 return -1;
 121
 122         if (memcmp(ns->oem_id, "NTFS", 4) != 0)
 123                 return -1;
 124
 125         volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
 126
 127         sector_size = le16_to_cpu(ns->bytes_per_sector);
 128         cluster_size = ns->sectors_per_cluster * sector_size;
 129         mft_cluster = le64_to_cpu(ns->mft_cluster_location);
 130         mft_off = mft_cluster * cluster_size;
 131
 132         if (ns->cluster_per_mft_record < 0)
 133                 /* size = -log2(mft_record_size); normally 1024 Bytes */
 134                 mft_record_size = 1 << -ns->cluster_per_mft_record;
 135         else
 136                 mft_record_size = ns->cluster_per_mft_record * cluster_size;
 137
 138         dbg("sectorsize  0x%x", sector_size);
 139         dbg("clustersize 0x%x", cluster_size);
 140         dbg("mftcluster  %llu", (unsigned long long) mft_cluster);
 141         dbg("mftoffset  0x%llx", (unsigned long long) mft_off);
 142         dbg("cluster per mft_record  %i", ns->cluster_per_mft_record);
 143         dbg("mft record size  %i", mft_record_size);
 144
 145         buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
 146                         mft_record_size);
 147         if (buf == NULL)
 148                 goto found;
 149
 150         mftr = (struct master_file_table_record*) buf;
 151
 152         dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
 153         if (memcmp(mftr->magic, "FILE", 4) != 0)
 154                 goto found;
 155
 156         attr_off = le16_to_cpu(mftr->attrs_offset);
 157         dbg("file $Volume's attributes are at offset %i", attr_off);
 158
 159         while (1) {
 160                 struct file_attribute *attr;
 161
 162                 attr = (struct file_attribute*) &buf[attr_off];
 163                 attr_type = le32_to_cpu(attr->type);
 164                 attr_len = le32_to_cpu(attr->len);
 165                 val_off = le16_to_cpu(attr->value_offset);
 166                 val_len = le32_to_cpu(attr->value_len);
 167                 attr_off += attr_len;
 168
 169                 if (attr_len == 0)
 170                         break;
 171
 172                 if (attr_off >= mft_record_size)
 173                         break;
 174
 175                 if (attr_type == MFT_RECORD_ATTR_END)
 176                         break;
 177
 178                 dbg("found attribute type 0x%x, len %i, at offset %i",
 179                         attr_type, attr_len, attr_off);
 180
 181 //              if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
 182 //                      struct volume_info *info;
 183 //                      dbg("found info, len %i", val_len);
 184 //                      info = (struct volume_info*) (((uint8_t *) attr) + val_off);
 185 //                      snprintf(id->type_version, sizeof(id->type_version)-1,
 186 //                               "%u.%u", info->major_ver, info->minor_ver);
 187 //              }
 188
 189                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 190                         dbg("found label, len %i", val_len);
 191                         if (val_len > VOLUME_ID_LABEL_SIZE)
 192                                 val_len = VOLUME_ID_LABEL_SIZE;
 193
 194                         val = ((uint8_t *) attr) + val_off;
 195 //                      volume_id_set_label_raw(id, val, val_len);
 196                         volume_id_set_label_unicode16(id, val, LE, val_len);
 197                 }
 198         }
 199
 200  found:
 201 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 202         IF_FEATURE_BLKID_TYPE(id->type = "ntfs";)
 203
 204         return 0;
 205 }