2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation version 2 of the License.
26 #include "volume_id.h"
31 struct ntfs_super_block {
34 uint16_t bytes_per_sector;
35 uint8_t sectors_per_cluster;
36 uint16_t reserved_sectors;
38 uint16_t root_entries;
41 uint16_t sectors_per_fat;
42 uint16_t sectors_per_track;
44 uint32_t hidden_sectors;
45 uint32_t large_sectors;
47 uint64_t number_of_sectors;
48 uint64_t mft_cluster_location;
49 uint64_t mft_mirror_cluster_location;
50 int8_t cluster_per_mft_record;
52 int8_t cluster_per_index_record;
54 uint8_t volume_serial[8];
56 } __attribute__((__packed__)) *ns;
58 struct master_file_table_record {
63 uint16_t sequence_number;
65 uint16_t attrs_offset;
67 uint32_t bytes_in_use;
68 uint32_t bytes_allocated;
69 } __attribute__((__packed__)) *mftr;
71 struct file_attribute {
80 uint16_t value_offset;
81 } __attribute__((__packed__)) *attr;
87 } __attribute__((__packed__)) *info;
89 #define MFT_RECORD_VOLUME 3
90 #define MFT_RECORD_ATTR_VOLUME_NAME 0x60
91 #define MFT_RECORD_ATTR_VOLUME_INFO 0x70
92 #define MFT_RECORD_ATTR_OBJECT_ID 0x40
93 #define MFT_RECORD_ATTR_END 0xffffffffu
95 int volume_id_probe_ntfs(struct volume_id *id, uint64_t off)
97 unsigned int sector_size;
98 unsigned int cluster_size;
101 unsigned int mft_record_size;
102 unsigned int attr_type;
103 unsigned int attr_off;
104 unsigned int attr_len;
105 unsigned int val_off;
106 unsigned int val_len;
110 dbg("probing at offset 0x%llx", (unsigned long long) off);
112 ns = (struct ntfs_super_block *) volume_id_get_buffer(id, off, 0x200);
116 if (memcmp(ns->oem_id, "NTFS", 4) != 0)
119 volume_id_set_uuid(id, ns->volume_serial, UUID_NTFS);
121 sector_size = le16_to_cpu(ns->bytes_per_sector);
122 cluster_size = ns->sectors_per_cluster * sector_size;
123 mft_cluster = le64_to_cpu(ns->mft_cluster_location);
124 mft_off = mft_cluster * cluster_size;
126 if (ns->cluster_per_mft_record < 0)
127 /* size = -log2(mft_record_size); normally 1024 Bytes */
128 mft_record_size = 1 << -ns->cluster_per_mft_record;
130 mft_record_size = ns->cluster_per_mft_record * cluster_size;
132 dbg("sectorsize 0x%x", sector_size);
133 dbg("clustersize 0x%x", cluster_size);
134 dbg("mftcluster %llu", (unsigned long long) mft_cluster);
135 dbg("mftoffset 0x%llx", (unsigned long long) mft_off);
136 dbg("cluster per mft_record %i", ns->cluster_per_mft_record);
137 dbg("mft record size %i", mft_record_size);
139 buf = volume_id_get_buffer(id, off + mft_off + (MFT_RECORD_VOLUME * mft_record_size),
144 mftr = (struct master_file_table_record*) buf;
146 dbg("mftr->magic '%c%c%c%c'", mftr->magic[0], mftr->magic[1], mftr->magic[2], mftr->magic[3]);
147 if (memcmp(mftr->magic, "FILE", 4) != 0)
150 attr_off = le16_to_cpu(mftr->attrs_offset);
151 dbg("file $Volume's attributes are at offset %i", attr_off);
154 attr = (struct file_attribute*) &buf[attr_off];
155 attr_type = le32_to_cpu(attr->type);
156 attr_len = le16_to_cpu(attr->len);
157 val_off = le16_to_cpu(attr->value_offset);
158 val_len = le32_to_cpu(attr->value_len);
159 attr_off += attr_len;
164 if (attr_off >= mft_record_size)
167 if (attr_type == MFT_RECORD_ATTR_END)
170 dbg("found attribute type 0x%x, len %i, at offset %i",
171 attr_type, attr_len, attr_off);
173 if (attr_type == MFT_RECORD_ATTR_VOLUME_INFO) {
174 dbg("found info, len %i", val_len);
175 info = (struct volume_info*) (((uint8_t *) attr) + val_off);
176 snprintf(id->type_version, sizeof(id->type_version)-1,
177 "%u.%u", info->major_ver, info->minor_ver);
180 if (attr_type == MFT_RECORD_ATTR_VOLUME_NAME) {
181 dbg("found label, len %i", val_len);
182 if (val_len > VOLUME_ID_LABEL_SIZE)
183 val_len = VOLUME_ID_LABEL_SIZE;
185 val = ((uint8_t *) attr) + val_off;
186 volume_id_set_label_raw(id, val, val_len);
187 volume_id_set_label_unicode16(id, val, LE, val_len);
192 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);