2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
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.
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.
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
36 #include "volume_id.h"
41 struct ntfs_super_block {
44 uint16_t bytes_per_sector;
45 uint8_t sectors_per_cluster;
46 uint16_t reserved_sectors;
48 uint16_t root_entries;
51 uint16_t sectors_per_fat;
52 uint16_t sectors_per_track;
54 uint32_t hidden_sectors;
55 uint32_t large_sectors;
57 uint64_t number_of_sectors;
58 uint64_t mft_cluster_location;
59 uint64_t mft_mirror_cluster_location;
60 int8_t cluster_per_mft_record;
62 int8_t cluster_per_index_record;
64 uint8_t volume_serial[8];
66 } __attribute__((__packed__)) *ns;
68 struct master_file_table_record {
73 uint16_t sequence_number;
75 uint16_t attrs_offset;
77 uint32_t bytes_in_use;
78 uint32_t bytes_allocated;
79 } __attribute__((__packed__)) *mftr;
81 struct file_attribute {
90 uint16_t value_offset;
91 } __attribute__((__packed__)) *attr;
97 } __attribute__((__packed__)) *info;
99 #define MFT_RECORD_VOLUME 3
100 #define MFT_RECORD_ATTR_VOLUME_NAME 0x60
101 #define MFT_RECORD_ATTR_VOLUME_INFO 0x70
102 #define MFT_RECORD_ATTR_OBJECT_ID 0x40
103 #define MFT_RECORD_ATTR_END 0xffffffffu
105 int volume_id_probe_ntfs(struct volume_id *id, uint64_t off)
107 unsigned int sector_size;
108 unsigned int cluster_size;
109 uint64_t mft_cluster;
111 unsigned int mft_record_size;
112 unsigned int attr_type;
113 unsigned int attr_off;
114 unsigned int attr_len;
115 unsigned int val_off;
116 unsigned int val_len;
120 dbg("probing at offset 0x%llx", (unsigned long long) off);
122 ns = (struct ntfs_super_block *) volume_id_get_buffer(id, off, 0x200);
126 if (memcmp(ns->oem_id, "NTFS", 4) != 0)
129 volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
131 sector_size = le16_to_cpu(ns->bytes_per_sector);
132 cluster_size = ns->sectors_per_cluster * sector_size;
133 mft_cluster = le64_to_cpu(ns->mft_cluster_location);
134 mft_off = mft_cluster * cluster_size;
136 if (ns->cluster_per_mft_record < 0)
137 /* size = -log2(mft_record_size); normally 1024 Bytes */
138 mft_record_size = 1 << -ns->cluster_per_mft_record;
140 mft_record_size = ns->cluster_per_mft_record * cluster_size;
142 dbg("sectorsize 0x%x", sector_size);
143 dbg("clustersize 0x%x", cluster_size);
144 dbg("mftcluster %llu", (unsigned long long) mft_cluster);
145 dbg("mftoffset 0x%llx", (unsigned long long) mft_off);
146 dbg("cluster per mft_record %i", ns->cluster_per_mft_record);
147 dbg("mft record size %i", mft_record_size);
149 buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
154 mftr = (struct master_file_table_record*) buf;
156 dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
157 if (memcmp(mftr->magic, "FILE", 4) != 0)
160 attr_off = le16_to_cpu(mftr->attrs_offset);
161 dbg("file $Volume's attributes are at offset %i", attr_off);
164 attr = (struct file_attribute*) &buf[attr_off];
165 attr_type = le32_to_cpu(attr->type);
166 attr_len = le16_to_cpu(attr->len);
167 val_off = le16_to_cpu(attr->value_offset);
168 val_len = le32_to_cpu(attr->value_len);
169 attr_off += attr_len;
174 if (attr_off >= mft_record_size)
177 if (attr_type == MFT_RECORD_ATTR_END)
180 dbg("found attribute type 0x%x, len %i, at offset %i",
181 attr_type, attr_len, attr_off);
183 if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
184 dbg("found info, len %i", val_len);
185 info = (struct volume_info*) (((uint8_t *) attr) + val_off);
186 snprintf(id->type_version, sizeof(id->type_version)-1,
187 "%u.%u", info->major_ver, info->minor_ver);
190 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
191 dbg("found label, len %i", val_len);
192 if (val_len > VOLUME_ID_LABEL_SIZE)
193 val_len = VOLUME_ID_LABEL_SIZE;
195 val = ((uint8_t *) attr) + val_off;
196 volume_id_set_label_raw(id, val, val_len);
197 volume_id_set_label_unicode16(id, val, LE, val_len);
202 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);