release/src/router/busybox/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 #include "volume_id_internal.h"
  22
  23 struct ntfs_super_block {
  24         uint8_t         jump[3];
  25         uint8_t         oem_id[8];
  26         uint16_t        bytes_per_sector;
  27         uint8_t         sectors_per_cluster;
  28         uint16_t        reserved_sectors;
  29         uint8_t         fats;
  30         uint16_t        root_entries;
  31         uint16_t        sectors;
  32         uint8_t         media_type;
  33         uint16_t        sectors_per_fat;
  34         uint16_t        sectors_per_track;
  35         uint16_t        heads;
  36         uint32_t        hidden_sectors;
  37         uint32_t        large_sectors;
  38         uint16_t        unused[2];
  39         uint64_t        number_of_sectors;
  40         uint64_t        mft_cluster_location;
  41         uint64_t        mft_mirror_cluster_location;
  42         int8_t          cluster_per_mft_record;
  43         uint8_t         reserved1[3];
  44         int8_t          cluster_per_index_record;
  45         uint8_t         reserved2[3];
  46         uint8_t         volume_serial[8];
  47         uint16_t        checksum;
  48 } __attribute__((__packed__));
  49
  50 struct master_file_table_record {
  51         uint8_t         magic[4];
  52         uint16_t        usa_ofs;
  53         uint16_t        usa_count;
  54         uint64_t        lsn;
  55         uint16_t        sequence_number;
  56         uint16_t        link_count;
  57         uint16_t        attrs_offset;
  58         uint16_t        flags;
  59         uint32_t        bytes_in_use;
  60         uint32_t        bytes_allocated;
  61 } __attribute__((__packed__));
  62
  63 struct file_attribute {
  64         uint32_t        type;
  65         uint32_t        len;
  66         uint8_t         non_resident;
  67         uint8_t         name_len;
  68         uint16_t        name_offset;
  69         uint16_t        flags;
  70         uint16_t        instance;
  71         uint32_t        value_len;
  72         uint16_t        value_offset;
  73 } __attribute__((__packed__));
  74
  75 struct volume_info {
  76         uint64_t        reserved;
  77         uint8_t         major_ver;
  78         uint8_t         minor_ver;
  79 } __attribute__((__packed__));
  80
  81 #define MFT_RECORD_VOLUME                       3
  82 #define MFT_RECORD_ATTR_VOLUME_NAME             0x60
  83 #define MFT_RECORD_ATTR_VOLUME_INFO             0x70
  84 #define MFT_RECORD_ATTR_OBJECT_ID               0x40
  85 #define MFT_RECORD_ATTR_END                     0xffffffffu
  86
  87 int volume_id_probe_ntfs(struct volume_id *id /*,uint64_t off*/)
  88 {
  89 #define off ((uint64_t)0)
  90         unsigned sector_size;
  91         unsigned cluster_size;
  92         uint64_t mft_cluster;
  93         uint64_t mft_off;
  94         unsigned mft_record_size;
  95         unsigned attr_type;
  96         unsigned attr_off;
  97         unsigned attr_len;
  98         unsigned val_off;
  99         unsigned val_len;
 100         struct master_file_table_record *mftr;
 101         struct ntfs_super_block *ns;
 102         const uint8_t *buf;
 103         const uint8_t *val;
 104
 105         dbg("probing at offset 0x%llx", (unsigned long long) off);
 106
 107         ns = volume_id_get_buffer(id, off, 0x200);
 108         if (ns == NULL)
 109                 return -1;
 110
 111         if (memcmp(ns->oem_id, "NTFS", 4) != 0)
 112                 return -1;
 113
 114         volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
 115
 116         sector_size = le16_to_cpu(ns->bytes_per_sector);
 117         cluster_size = ns->sectors_per_cluster * sector_size;
 118         mft_cluster = le64_to_cpu(ns->mft_cluster_location);
 119         mft_off = mft_cluster * cluster_size;
 120
 121         if (ns->cluster_per_mft_record < 0)
 122                 /* size = -log2(mft_record_size); normally 1024 Bytes */
 123                 mft_record_size = 1 << -ns->cluster_per_mft_record;
 124         else
 125                 mft_record_size = ns->cluster_per_mft_record * cluster_size;
 126
 127         dbg("sectorsize  0x%x", sector_size);
 128         dbg("clustersize 0x%x", cluster_size);
 129         dbg("mftcluster  %llu", (unsigned long long) mft_cluster);
 130         dbg("mftoffset  0x%llx", (unsigned long long) mft_off);
 131         dbg("cluster per mft_record  %i", ns->cluster_per_mft_record);
 132         dbg("mft record size  %i", mft_record_size);
 133
 134         buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
 135                          mft_record_size);
 136         if (buf == NULL)
 137                 goto found;
 138
 139         mftr = (struct master_file_table_record*) buf;
 140
 141         dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
 142         if (memcmp(mftr->magic, "FILE", 4) != 0)
 143                 goto found;
 144
 145         attr_off = le16_to_cpu(mftr->attrs_offset);
 146         dbg("file $Volume's attributes are at offset %i", attr_off);
 147
 148         while (1) {
 149                 struct file_attribute *attr;
 150
 151                 attr = (struct file_attribute*) &buf[attr_off];
 152                 attr_type = le32_to_cpu(attr->type);
 153                 attr_len = le16_to_cpu(attr->len);
 154                 val_off = le16_to_cpu(attr->value_offset);
 155                 val_len = le32_to_cpu(attr->value_len);
 156                 attr_off += attr_len;
 157
 158                 if (attr_len == 0)
 159                         break;
 160
 161                 if (attr_off >= mft_record_size)
 162                         break;
 163
 164                 if (attr_type == MFT_RECORD_ATTR_END)
 165                         break;
 166
 167                 dbg("found attribute type 0x%x, len %i, at offset %i",
 168                     attr_type, attr_len, attr_off);
 169
 170 //              if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
 171 //                      struct volume_info *info;
 172 //                      dbg("found info, len %i", val_len);
 173 //                      info = (struct volume_info*) (((uint8_t *) attr) + val_off);
 174 //                      snprintf(id->type_version, sizeof(id->type_version)-1,
 175 //                               "%u.%u", info->major_ver, info->minor_ver);
 176 //              }
 177
 178                 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
 179                         dbg("found label, len %i", val_len);
 180                         if (val_len > VOLUME_ID_LABEL_SIZE)
 181                                 val_len = VOLUME_ID_LABEL_SIZE;
 182
 183                         val = ((uint8_t *) attr) + val_off;
 184 //                      volume_id_set_label_raw(id, val, val_len);
 185                         volume_id_set_label_unicode16(id, val, LE, val_len);
 186                 }
 187         }
 188
 189  found:
 190 //      volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 191 //      id->type = "ntfs";
 192
 193         return 0;
 194 }