cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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layout.h (98500B)


      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 * layout.h - All NTFS associated on-disk structures. Part of the Linux-NTFS
      4 *	      project.
      5 *
      6 * Copyright (c) 2001-2005 Anton Altaparmakov
      7 * Copyright (c) 2002 Richard Russon
      8 */
      9
     10#ifndef _LINUX_NTFS_LAYOUT_H
     11#define _LINUX_NTFS_LAYOUT_H
     12
     13#include <linux/types.h>
     14#include <linux/bitops.h>
     15#include <linux/list.h>
     16#include <asm/byteorder.h>
     17
     18#include "types.h"
     19
     20/* The NTFS oem_id "NTFS    " */
     21#define magicNTFS	cpu_to_le64(0x202020205346544eULL)
     22
     23/*
     24 * Location of bootsector on partition:
     25 *	The standard NTFS_BOOT_SECTOR is on sector 0 of the partition.
     26 *	On NT4 and above there is one backup copy of the boot sector to
     27 *	be found on the last sector of the partition (not normally accessible
     28 *	from within Windows as the bootsector contained number of sectors
     29 *	value is one less than the actual value!).
     30 *	On versions of NT 3.51 and earlier, the backup copy was located at
     31 *	number of sectors/2 (integer divide), i.e. in the middle of the volume.
     32 */
     33
     34/*
     35 * BIOS parameter block (bpb) structure.
     36 */
     37typedef struct {
     38	le16 bytes_per_sector;		/* Size of a sector in bytes. */
     39	u8  sectors_per_cluster;	/* Size of a cluster in sectors. */
     40	le16 reserved_sectors;		/* zero */
     41	u8  fats;			/* zero */
     42	le16 root_entries;		/* zero */
     43	le16 sectors;			/* zero */
     44	u8  media_type;			/* 0xf8 = hard disk */
     45	le16 sectors_per_fat;		/* zero */
     46	le16 sectors_per_track;		/* irrelevant */
     47	le16 heads;			/* irrelevant */
     48	le32 hidden_sectors;		/* zero */
     49	le32 large_sectors;		/* zero */
     50} __attribute__ ((__packed__)) BIOS_PARAMETER_BLOCK;
     51
     52/*
     53 * NTFS boot sector structure.
     54 */
     55typedef struct {
     56	u8  jump[3];			/* Irrelevant (jump to boot up code).*/
     57	le64 oem_id;			/* Magic "NTFS    ". */
     58	BIOS_PARAMETER_BLOCK bpb;	/* See BIOS_PARAMETER_BLOCK. */
     59	u8  unused[4];			/* zero, NTFS diskedit.exe states that
     60					   this is actually:
     61						__u8 physical_drive;	// 0x80
     62						__u8 current_head;	// zero
     63						__u8 extended_boot_signature;
     64									// 0x80
     65						__u8 unused;		// zero
     66					 */
     67/*0x28*/sle64 number_of_sectors;	/* Number of sectors in volume. Gives
     68					   maximum volume size of 2^63 sectors.
     69					   Assuming standard sector size of 512
     70					   bytes, the maximum byte size is
     71					   approx. 4.7x10^21 bytes. (-; */
     72	sle64 mft_lcn;			/* Cluster location of mft data. */
     73	sle64 mftmirr_lcn;		/* Cluster location of copy of mft. */
     74	s8  clusters_per_mft_record;	/* Mft record size in clusters. */
     75	u8  reserved0[3];		/* zero */
     76	s8  clusters_per_index_record;	/* Index block size in clusters. */
     77	u8  reserved1[3];		/* zero */
     78	le64 volume_serial_number;	/* Irrelevant (serial number). */
     79	le32 checksum;			/* Boot sector checksum. */
     80/*0x54*/u8  bootstrap[426];		/* Irrelevant (boot up code). */
     81	le16 end_of_sector_marker;	/* End of bootsector magic. Always is
     82					   0xaa55 in little endian. */
     83/* sizeof() = 512 (0x200) bytes */
     84} __attribute__ ((__packed__)) NTFS_BOOT_SECTOR;
     85
     86/*
     87 * Magic identifiers present at the beginning of all ntfs record containing
     88 * records (like mft records for example).
     89 */
     90enum {
     91	/* Found in $MFT/$DATA. */
     92	magic_FILE = cpu_to_le32(0x454c4946), /* Mft entry. */
     93	magic_INDX = cpu_to_le32(0x58444e49), /* Index buffer. */
     94	magic_HOLE = cpu_to_le32(0x454c4f48), /* ? (NTFS 3.0+?) */
     95
     96	/* Found in $LogFile/$DATA. */
     97	magic_RSTR = cpu_to_le32(0x52545352), /* Restart page. */
     98	magic_RCRD = cpu_to_le32(0x44524352), /* Log record page. */
     99
    100	/* Found in $LogFile/$DATA.  (May be found in $MFT/$DATA, also?) */
    101	magic_CHKD = cpu_to_le32(0x444b4843), /* Modified by chkdsk. */
    102
    103	/* Found in all ntfs record containing records. */
    104	magic_BAAD = cpu_to_le32(0x44414142), /* Failed multi sector
    105						       transfer was detected. */
    106	/*
    107	 * Found in $LogFile/$DATA when a page is full of 0xff bytes and is
    108	 * thus not initialized.  Page must be initialized before using it.
    109	 */
    110	magic_empty = cpu_to_le32(0xffffffff) /* Record is empty. */
    111};
    112
    113typedef le32 NTFS_RECORD_TYPE;
    114
    115/*
    116 * Generic magic comparison macros. Finally found a use for the ## preprocessor
    117 * operator! (-8
    118 */
    119
    120static inline bool __ntfs_is_magic(le32 x, NTFS_RECORD_TYPE r)
    121{
    122	return (x == r);
    123}
    124#define ntfs_is_magic(x, m)	__ntfs_is_magic(x, magic_##m)
    125
    126static inline bool __ntfs_is_magicp(le32 *p, NTFS_RECORD_TYPE r)
    127{
    128	return (*p == r);
    129}
    130#define ntfs_is_magicp(p, m)	__ntfs_is_magicp(p, magic_##m)
    131
    132/*
    133 * Specialised magic comparison macros for the NTFS_RECORD_TYPEs defined above.
    134 */
    135#define ntfs_is_file_record(x)		( ntfs_is_magic (x, FILE) )
    136#define ntfs_is_file_recordp(p)		( ntfs_is_magicp(p, FILE) )
    137#define ntfs_is_mft_record(x)		( ntfs_is_file_record (x) )
    138#define ntfs_is_mft_recordp(p)		( ntfs_is_file_recordp(p) )
    139#define ntfs_is_indx_record(x)		( ntfs_is_magic (x, INDX) )
    140#define ntfs_is_indx_recordp(p)		( ntfs_is_magicp(p, INDX) )
    141#define ntfs_is_hole_record(x)		( ntfs_is_magic (x, HOLE) )
    142#define ntfs_is_hole_recordp(p)		( ntfs_is_magicp(p, HOLE) )
    143
    144#define ntfs_is_rstr_record(x)		( ntfs_is_magic (x, RSTR) )
    145#define ntfs_is_rstr_recordp(p)		( ntfs_is_magicp(p, RSTR) )
    146#define ntfs_is_rcrd_record(x)		( ntfs_is_magic (x, RCRD) )
    147#define ntfs_is_rcrd_recordp(p)		( ntfs_is_magicp(p, RCRD) )
    148
    149#define ntfs_is_chkd_record(x)		( ntfs_is_magic (x, CHKD) )
    150#define ntfs_is_chkd_recordp(p)		( ntfs_is_magicp(p, CHKD) )
    151
    152#define ntfs_is_baad_record(x)		( ntfs_is_magic (x, BAAD) )
    153#define ntfs_is_baad_recordp(p)		( ntfs_is_magicp(p, BAAD) )
    154
    155#define ntfs_is_empty_record(x)		( ntfs_is_magic (x, empty) )
    156#define ntfs_is_empty_recordp(p)	( ntfs_is_magicp(p, empty) )
    157
    158/*
    159 * The Update Sequence Array (usa) is an array of the le16 values which belong
    160 * to the end of each sector protected by the update sequence record in which
    161 * this array is contained. Note that the first entry is the Update Sequence
    162 * Number (usn), a cyclic counter of how many times the protected record has
    163 * been written to disk. The values 0 and -1 (ie. 0xffff) are not used. All
    164 * last le16's of each sector have to be equal to the usn (during reading) or
    165 * are set to it (during writing). If they are not, an incomplete multi sector
    166 * transfer has occurred when the data was written.
    167 * The maximum size for the update sequence array is fixed to:
    168 *	maximum size = usa_ofs + (usa_count * 2) = 510 bytes
    169 * The 510 bytes comes from the fact that the last le16 in the array has to
    170 * (obviously) finish before the last le16 of the first 512-byte sector.
    171 * This formula can be used as a consistency check in that usa_ofs +
    172 * (usa_count * 2) has to be less than or equal to 510.
    173 */
    174typedef struct {
    175	NTFS_RECORD_TYPE magic;	/* A four-byte magic identifying the record
    176				   type and/or status. */
    177	le16 usa_ofs;		/* Offset to the Update Sequence Array (usa)
    178				   from the start of the ntfs record. */
    179	le16 usa_count;		/* Number of le16 sized entries in the usa
    180				   including the Update Sequence Number (usn),
    181				   thus the number of fixups is the usa_count
    182				   minus 1. */
    183} __attribute__ ((__packed__)) NTFS_RECORD;
    184
    185/*
    186 * System files mft record numbers. All these files are always marked as used
    187 * in the bitmap attribute of the mft; presumably in order to avoid accidental
    188 * allocation for random other mft records. Also, the sequence number for each
    189 * of the system files is always equal to their mft record number and it is
    190 * never modified.
    191 */
    192typedef enum {
    193	FILE_MFT       = 0,	/* Master file table (mft). Data attribute
    194				   contains the entries and bitmap attribute
    195				   records which ones are in use (bit==1). */
    196	FILE_MFTMirr   = 1,	/* Mft mirror: copy of first four mft records
    197				   in data attribute. If cluster size > 4kiB,
    198				   copy of first N mft records, with
    199					N = cluster_size / mft_record_size. */
    200	FILE_LogFile   = 2,	/* Journalling log in data attribute. */
    201	FILE_Volume    = 3,	/* Volume name attribute and volume information
    202				   attribute (flags and ntfs version). Windows
    203				   refers to this file as volume DASD (Direct
    204				   Access Storage Device). */
    205	FILE_AttrDef   = 4,	/* Array of attribute definitions in data
    206				   attribute. */
    207	FILE_root      = 5,	/* Root directory. */
    208	FILE_Bitmap    = 6,	/* Allocation bitmap of all clusters (lcns) in
    209				   data attribute. */
    210	FILE_Boot      = 7,	/* Boot sector (always at cluster 0) in data
    211				   attribute. */
    212	FILE_BadClus   = 8,	/* Contains all bad clusters in the non-resident
    213				   data attribute. */
    214	FILE_Secure    = 9,	/* Shared security descriptors in data attribute
    215				   and two indexes into the descriptors.
    216				   Appeared in Windows 2000. Before that, this
    217				   file was named $Quota but was unused. */
    218	FILE_UpCase    = 10,	/* Uppercase equivalents of all 65536 Unicode
    219				   characters in data attribute. */
    220	FILE_Extend    = 11,	/* Directory containing other system files (eg.
    221				   $ObjId, $Quota, $Reparse and $UsnJrnl). This
    222				   is new to NTFS3.0. */
    223	FILE_reserved12 = 12,	/* Reserved for future use (records 12-15). */
    224	FILE_reserved13 = 13,
    225	FILE_reserved14 = 14,
    226	FILE_reserved15 = 15,
    227	FILE_first_user = 16,	/* First user file, used as test limit for
    228				   whether to allow opening a file or not. */
    229} NTFS_SYSTEM_FILES;
    230
    231/*
    232 * These are the so far known MFT_RECORD_* flags (16-bit) which contain
    233 * information about the mft record in which they are present.
    234 */
    235enum {
    236	MFT_RECORD_IN_USE	= cpu_to_le16(0x0001),
    237	MFT_RECORD_IS_DIRECTORY = cpu_to_le16(0x0002),
    238} __attribute__ ((__packed__));
    239
    240typedef le16 MFT_RECORD_FLAGS;
    241
    242/*
    243 * mft references (aka file references or file record segment references) are
    244 * used whenever a structure needs to refer to a record in the mft.
    245 *
    246 * A reference consists of a 48-bit index into the mft and a 16-bit sequence
    247 * number used to detect stale references.
    248 *
    249 * For error reporting purposes we treat the 48-bit index as a signed quantity.
    250 *
    251 * The sequence number is a circular counter (skipping 0) describing how many
    252 * times the referenced mft record has been (re)used. This has to match the
    253 * sequence number of the mft record being referenced, otherwise the reference
    254 * is considered stale and removed (FIXME: only ntfsck or the driver itself?).
    255 *
    256 * If the sequence number is zero it is assumed that no sequence number
    257 * consistency checking should be performed.
    258 *
    259 * FIXME: Since inodes are 32-bit as of now, the driver needs to always check
    260 * for high_part being 0 and if not either BUG(), cause a panic() or handle
    261 * the situation in some other way. This shouldn't be a problem as a volume has
    262 * to become HUGE in order to need more than 32-bits worth of mft records.
    263 * Assuming the standard mft record size of 1kb only the records (never mind
    264 * the non-resident attributes, etc.) would require 4Tb of space on their own
    265 * for the first 32 bits worth of records. This is only if some strange person
    266 * doesn't decide to foul play and make the mft sparse which would be a really
    267 * horrible thing to do as it would trash our current driver implementation. )-:
    268 * Do I hear screams "we want 64-bit inodes!" ?!? (-;
    269 *
    270 * FIXME: The mft zone is defined as the first 12% of the volume. This space is
    271 * reserved so that the mft can grow contiguously and hence doesn't become
    272 * fragmented. Volume free space includes the empty part of the mft zone and
    273 * when the volume's free 88% are used up, the mft zone is shrunk by a factor
    274 * of 2, thus making more space available for more files/data. This process is
    275 * repeated every time there is no more free space except for the mft zone until
    276 * there really is no more free space.
    277 */
    278
    279/*
    280 * Typedef the MFT_REF as a 64-bit value for easier handling.
    281 * Also define two unpacking macros to get to the reference (MREF) and
    282 * sequence number (MSEQNO) respectively.
    283 * The _LE versions are to be applied on little endian MFT_REFs.
    284 * Note: The _LE versions will return a CPU endian formatted value!
    285 */
    286#define MFT_REF_MASK_CPU 0x0000ffffffffffffULL
    287#define MFT_REF_MASK_LE cpu_to_le64(MFT_REF_MASK_CPU)
    288
    289typedef u64 MFT_REF;
    290typedef le64 leMFT_REF;
    291
    292#define MK_MREF(m, s)	((MFT_REF)(((MFT_REF)(s) << 48) |		\
    293					((MFT_REF)(m) & MFT_REF_MASK_CPU)))
    294#define MK_LE_MREF(m, s) cpu_to_le64(MK_MREF(m, s))
    295
    296#define MREF(x)		((unsigned long)((x) & MFT_REF_MASK_CPU))
    297#define MSEQNO(x)	((u16)(((x) >> 48) & 0xffff))
    298#define MREF_LE(x)	((unsigned long)(le64_to_cpu(x) & MFT_REF_MASK_CPU))
    299#define MSEQNO_LE(x)	((u16)((le64_to_cpu(x) >> 48) & 0xffff))
    300
    301#define IS_ERR_MREF(x)	(((x) & 0x0000800000000000ULL) ? true : false)
    302#define ERR_MREF(x)	((u64)((s64)(x)))
    303#define MREF_ERR(x)	((int)((s64)(x)))
    304
    305/*
    306 * The mft record header present at the beginning of every record in the mft.
    307 * This is followed by a sequence of variable length attribute records which
    308 * is terminated by an attribute of type AT_END which is a truncated attribute
    309 * in that it only consists of the attribute type code AT_END and none of the
    310 * other members of the attribute structure are present.
    311 */
    312typedef struct {
    313/*Ofs*/
    314/*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
    315	NTFS_RECORD_TYPE magic;	/* Usually the magic is "FILE". */
    316	le16 usa_ofs;		/* See NTFS_RECORD definition above. */
    317	le16 usa_count;		/* See NTFS_RECORD definition above. */
    318
    319/*  8*/	le64 lsn;		/* $LogFile sequence number for this record.
    320				   Changed every time the record is modified. */
    321/* 16*/	le16 sequence_number;	/* Number of times this mft record has been
    322				   reused. (See description for MFT_REF
    323				   above.) NOTE: The increment (skipping zero)
    324				   is done when the file is deleted. NOTE: If
    325				   this is zero it is left zero. */
    326/* 18*/	le16 link_count;	/* Number of hard links, i.e. the number of
    327				   directory entries referencing this record.
    328				   NOTE: Only used in mft base records.
    329				   NOTE: When deleting a directory entry we
    330				   check the link_count and if it is 1 we
    331				   delete the file. Otherwise we delete the
    332				   FILE_NAME_ATTR being referenced by the
    333				   directory entry from the mft record and
    334				   decrement the link_count.
    335				   FIXME: Careful with Win32 + DOS names! */
    336/* 20*/	le16 attrs_offset;	/* Byte offset to the first attribute in this
    337				   mft record from the start of the mft record.
    338				   NOTE: Must be aligned to 8-byte boundary. */
    339/* 22*/	MFT_RECORD_FLAGS flags;	/* Bit array of MFT_RECORD_FLAGS. When a file
    340				   is deleted, the MFT_RECORD_IN_USE flag is
    341				   set to zero. */
    342/* 24*/	le32 bytes_in_use;	/* Number of bytes used in this mft record.
    343				   NOTE: Must be aligned to 8-byte boundary. */
    344/* 28*/	le32 bytes_allocated;	/* Number of bytes allocated for this mft
    345				   record. This should be equal to the mft
    346				   record size. */
    347/* 32*/	leMFT_REF base_mft_record;/* This is zero for base mft records.
    348				   When it is not zero it is a mft reference
    349				   pointing to the base mft record to which
    350				   this record belongs (this is then used to
    351				   locate the attribute list attribute present
    352				   in the base record which describes this
    353				   extension record and hence might need
    354				   modification when the extension record
    355				   itself is modified, also locating the
    356				   attribute list also means finding the other
    357				   potential extents, belonging to the non-base
    358				   mft record). */
    359/* 40*/	le16 next_attr_instance;/* The instance number that will be assigned to
    360				   the next attribute added to this mft record.
    361				   NOTE: Incremented each time after it is used.
    362				   NOTE: Every time the mft record is reused
    363				   this number is set to zero.  NOTE: The first
    364				   instance number is always 0. */
    365/* The below fields are specific to NTFS 3.1+ (Windows XP and above): */
    366/* 42*/ le16 reserved;		/* Reserved/alignment. */
    367/* 44*/ le32 mft_record_number;	/* Number of this mft record. */
    368/* sizeof() = 48 bytes */
    369/*
    370 * When (re)using the mft record, we place the update sequence array at this
    371 * offset, i.e. before we start with the attributes.  This also makes sense,
    372 * otherwise we could run into problems with the update sequence array
    373 * containing in itself the last two bytes of a sector which would mean that
    374 * multi sector transfer protection wouldn't work.  As you can't protect data
    375 * by overwriting it since you then can't get it back...
    376 * When reading we obviously use the data from the ntfs record header.
    377 */
    378} __attribute__ ((__packed__)) MFT_RECORD;
    379
    380/* This is the version without the NTFS 3.1+ specific fields. */
    381typedef struct {
    382/*Ofs*/
    383/*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
    384	NTFS_RECORD_TYPE magic;	/* Usually the magic is "FILE". */
    385	le16 usa_ofs;		/* See NTFS_RECORD definition above. */
    386	le16 usa_count;		/* See NTFS_RECORD definition above. */
    387
    388/*  8*/	le64 lsn;		/* $LogFile sequence number for this record.
    389				   Changed every time the record is modified. */
    390/* 16*/	le16 sequence_number;	/* Number of times this mft record has been
    391				   reused. (See description for MFT_REF
    392				   above.) NOTE: The increment (skipping zero)
    393				   is done when the file is deleted. NOTE: If
    394				   this is zero it is left zero. */
    395/* 18*/	le16 link_count;	/* Number of hard links, i.e. the number of
    396				   directory entries referencing this record.
    397				   NOTE: Only used in mft base records.
    398				   NOTE: When deleting a directory entry we
    399				   check the link_count and if it is 1 we
    400				   delete the file. Otherwise we delete the
    401				   FILE_NAME_ATTR being referenced by the
    402				   directory entry from the mft record and
    403				   decrement the link_count.
    404				   FIXME: Careful with Win32 + DOS names! */
    405/* 20*/	le16 attrs_offset;	/* Byte offset to the first attribute in this
    406				   mft record from the start of the mft record.
    407				   NOTE: Must be aligned to 8-byte boundary. */
    408/* 22*/	MFT_RECORD_FLAGS flags;	/* Bit array of MFT_RECORD_FLAGS. When a file
    409				   is deleted, the MFT_RECORD_IN_USE flag is
    410				   set to zero. */
    411/* 24*/	le32 bytes_in_use;	/* Number of bytes used in this mft record.
    412				   NOTE: Must be aligned to 8-byte boundary. */
    413/* 28*/	le32 bytes_allocated;	/* Number of bytes allocated for this mft
    414				   record. This should be equal to the mft
    415				   record size. */
    416/* 32*/	leMFT_REF base_mft_record;/* This is zero for base mft records.
    417				   When it is not zero it is a mft reference
    418				   pointing to the base mft record to which
    419				   this record belongs (this is then used to
    420				   locate the attribute list attribute present
    421				   in the base record which describes this
    422				   extension record and hence might need
    423				   modification when the extension record
    424				   itself is modified, also locating the
    425				   attribute list also means finding the other
    426				   potential extents, belonging to the non-base
    427				   mft record). */
    428/* 40*/	le16 next_attr_instance;/* The instance number that will be assigned to
    429				   the next attribute added to this mft record.
    430				   NOTE: Incremented each time after it is used.
    431				   NOTE: Every time the mft record is reused
    432				   this number is set to zero.  NOTE: The first
    433				   instance number is always 0. */
    434/* sizeof() = 42 bytes */
    435/*
    436 * When (re)using the mft record, we place the update sequence array at this
    437 * offset, i.e. before we start with the attributes.  This also makes sense,
    438 * otherwise we could run into problems with the update sequence array
    439 * containing in itself the last two bytes of a sector which would mean that
    440 * multi sector transfer protection wouldn't work.  As you can't protect data
    441 * by overwriting it since you then can't get it back...
    442 * When reading we obviously use the data from the ntfs record header.
    443 */
    444} __attribute__ ((__packed__)) MFT_RECORD_OLD;
    445
    446/*
    447 * System defined attributes (32-bit).  Each attribute type has a corresponding
    448 * attribute name (Unicode string of maximum 64 character length) as described
    449 * by the attribute definitions present in the data attribute of the $AttrDef
    450 * system file.  On NTFS 3.0 volumes the names are just as the types are named
    451 * in the below defines exchanging AT_ for the dollar sign ($).  If that is not
    452 * a revealing choice of symbol I do not know what is... (-;
    453 */
    454enum {
    455	AT_UNUSED			= cpu_to_le32(         0),
    456	AT_STANDARD_INFORMATION		= cpu_to_le32(      0x10),
    457	AT_ATTRIBUTE_LIST		= cpu_to_le32(      0x20),
    458	AT_FILE_NAME			= cpu_to_le32(      0x30),
    459	AT_OBJECT_ID			= cpu_to_le32(      0x40),
    460	AT_SECURITY_DESCRIPTOR		= cpu_to_le32(      0x50),
    461	AT_VOLUME_NAME			= cpu_to_le32(      0x60),
    462	AT_VOLUME_INFORMATION		= cpu_to_le32(      0x70),
    463	AT_DATA				= cpu_to_le32(      0x80),
    464	AT_INDEX_ROOT			= cpu_to_le32(      0x90),
    465	AT_INDEX_ALLOCATION		= cpu_to_le32(      0xa0),
    466	AT_BITMAP			= cpu_to_le32(      0xb0),
    467	AT_REPARSE_POINT		= cpu_to_le32(      0xc0),
    468	AT_EA_INFORMATION		= cpu_to_le32(      0xd0),
    469	AT_EA				= cpu_to_le32(      0xe0),
    470	AT_PROPERTY_SET			= cpu_to_le32(      0xf0),
    471	AT_LOGGED_UTILITY_STREAM	= cpu_to_le32(     0x100),
    472	AT_FIRST_USER_DEFINED_ATTRIBUTE	= cpu_to_le32(    0x1000),
    473	AT_END				= cpu_to_le32(0xffffffff)
    474};
    475
    476typedef le32 ATTR_TYPE;
    477
    478/*
    479 * The collation rules for sorting views/indexes/etc (32-bit).
    480 *
    481 * COLLATION_BINARY - Collate by binary compare where the first byte is most
    482 *	significant.
    483 * COLLATION_UNICODE_STRING - Collate Unicode strings by comparing their binary
    484 *	Unicode values, except that when a character can be uppercased, the
    485 *	upper case value collates before the lower case one.
    486 * COLLATION_FILE_NAME - Collate file names as Unicode strings. The collation
    487 *	is done very much like COLLATION_UNICODE_STRING. In fact I have no idea
    488 *	what the difference is. Perhaps the difference is that file names
    489 *	would treat some special characters in an odd way (see
    490 *	unistr.c::ntfs_collate_names() and unistr.c::legal_ansi_char_array[]
    491 *	for what I mean but COLLATION_UNICODE_STRING would not give any special
    492 *	treatment to any characters at all, but this is speculation.
    493 * COLLATION_NTOFS_ULONG - Sorting is done according to ascending le32 key
    494 *	values. E.g. used for $SII index in FILE_Secure, which sorts by
    495 *	security_id (le32).
    496 * COLLATION_NTOFS_SID - Sorting is done according to ascending SID values.
    497 *	E.g. used for $O index in FILE_Extend/$Quota.
    498 * COLLATION_NTOFS_SECURITY_HASH - Sorting is done first by ascending hash
    499 *	values and second by ascending security_id values. E.g. used for $SDH
    500 *	index in FILE_Secure.
    501 * COLLATION_NTOFS_ULONGS - Sorting is done according to a sequence of ascending
    502 *	le32 key values. E.g. used for $O index in FILE_Extend/$ObjId, which
    503 *	sorts by object_id (16-byte), by splitting up the object_id in four
    504 *	le32 values and using them as individual keys. E.g. take the following
    505 *	two security_ids, stored as follows on disk:
    506 *		1st: a1 61 65 b7 65 7b d4 11 9e 3d 00 e0 81 10 42 59
    507 *		2nd: 38 14 37 d2 d2 f3 d4 11 a5 21 c8 6b 79 b1 97 45
    508 *	To compare them, they are split into four le32 values each, like so:
    509 *		1st: 0xb76561a1 0x11d47b65 0xe0003d9e 0x59421081
    510 *		2nd: 0xd2371438 0x11d4f3d2 0x6bc821a5 0x4597b179
    511 *	Now, it is apparent why the 2nd object_id collates after the 1st: the
    512 *	first le32 value of the 1st object_id is less than the first le32 of
    513 *	the 2nd object_id. If the first le32 values of both object_ids were
    514 *	equal then the second le32 values would be compared, etc.
    515 */
    516enum {
    517	COLLATION_BINARY		= cpu_to_le32(0x00),
    518	COLLATION_FILE_NAME		= cpu_to_le32(0x01),
    519	COLLATION_UNICODE_STRING	= cpu_to_le32(0x02),
    520	COLLATION_NTOFS_ULONG		= cpu_to_le32(0x10),
    521	COLLATION_NTOFS_SID		= cpu_to_le32(0x11),
    522	COLLATION_NTOFS_SECURITY_HASH	= cpu_to_le32(0x12),
    523	COLLATION_NTOFS_ULONGS		= cpu_to_le32(0x13),
    524};
    525
    526typedef le32 COLLATION_RULE;
    527
    528/*
    529 * The flags (32-bit) describing attribute properties in the attribute
    530 * definition structure.  FIXME: This information is based on Regis's
    531 * information and, according to him, it is not certain and probably
    532 * incomplete.  The INDEXABLE flag is fairly certainly correct as only the file
    533 * name attribute has this flag set and this is the only attribute indexed in
    534 * NT4.
    535 */
    536enum {
    537	ATTR_DEF_INDEXABLE	= cpu_to_le32(0x02), /* Attribute can be
    538					indexed. */
    539	ATTR_DEF_MULTIPLE	= cpu_to_le32(0x04), /* Attribute type
    540					can be present multiple times in the
    541					mft records of an inode. */
    542	ATTR_DEF_NOT_ZERO	= cpu_to_le32(0x08), /* Attribute value
    543					must contain at least one non-zero
    544					byte. */
    545	ATTR_DEF_INDEXED_UNIQUE	= cpu_to_le32(0x10), /* Attribute must be
    546					indexed and the attribute value must be
    547					unique for the attribute type in all of
    548					the mft records of an inode. */
    549	ATTR_DEF_NAMED_UNIQUE	= cpu_to_le32(0x20), /* Attribute must be
    550					named and the name must be unique for
    551					the attribute type in all of the mft
    552					records of an inode. */
    553	ATTR_DEF_RESIDENT	= cpu_to_le32(0x40), /* Attribute must be
    554					resident. */
    555	ATTR_DEF_ALWAYS_LOG	= cpu_to_le32(0x80), /* Always log
    556					modifications to this attribute,
    557					regardless of whether it is resident or
    558					non-resident.  Without this, only log
    559					modifications if the attribute is
    560					resident. */
    561};
    562
    563typedef le32 ATTR_DEF_FLAGS;
    564
    565/*
    566 * The data attribute of FILE_AttrDef contains a sequence of attribute
    567 * definitions for the NTFS volume. With this, it is supposed to be safe for an
    568 * older NTFS driver to mount a volume containing a newer NTFS version without
    569 * damaging it (that's the theory. In practice it's: not damaging it too much).
    570 * Entries are sorted by attribute type. The flags describe whether the
    571 * attribute can be resident/non-resident and possibly other things, but the
    572 * actual bits are unknown.
    573 */
    574typedef struct {
    575/*hex ofs*/
    576/*  0*/	ntfschar name[0x40];		/* Unicode name of the attribute. Zero
    577					   terminated. */
    578/* 80*/	ATTR_TYPE type;			/* Type of the attribute. */
    579/* 84*/	le32 display_rule;		/* Default display rule.
    580					   FIXME: What does it mean? (AIA) */
    581/* 88*/ COLLATION_RULE collation_rule;	/* Default collation rule. */
    582/* 8c*/	ATTR_DEF_FLAGS flags;		/* Flags describing the attribute. */
    583/* 90*/	sle64 min_size;			/* Optional minimum attribute size. */
    584/* 98*/	sle64 max_size;			/* Maximum size of attribute. */
    585/* sizeof() = 0xa0 or 160 bytes */
    586} __attribute__ ((__packed__)) ATTR_DEF;
    587
    588/*
    589 * Attribute flags (16-bit).
    590 */
    591enum {
    592	ATTR_IS_COMPRESSED    = cpu_to_le16(0x0001),
    593	ATTR_COMPRESSION_MASK = cpu_to_le16(0x00ff), /* Compression method
    594							      mask.  Also, first
    595							      illegal value. */
    596	ATTR_IS_ENCRYPTED     = cpu_to_le16(0x4000),
    597	ATTR_IS_SPARSE	      = cpu_to_le16(0x8000),
    598} __attribute__ ((__packed__));
    599
    600typedef le16 ATTR_FLAGS;
    601
    602/*
    603 * Attribute compression.
    604 *
    605 * Only the data attribute is ever compressed in the current ntfs driver in
    606 * Windows. Further, compression is only applied when the data attribute is
    607 * non-resident. Finally, to use compression, the maximum allowed cluster size
    608 * on a volume is 4kib.
    609 *
    610 * The compression method is based on independently compressing blocks of X
    611 * clusters, where X is determined from the compression_unit value found in the
    612 * non-resident attribute record header (more precisely: X = 2^compression_unit
    613 * clusters). On Windows NT/2k, X always is 16 clusters (compression_unit = 4).
    614 *
    615 * There are three different cases of how a compression block of X clusters
    616 * can be stored:
    617 *
    618 *   1) The data in the block is all zero (a sparse block):
    619 *	  This is stored as a sparse block in the runlist, i.e. the runlist
    620 *	  entry has length = X and lcn = -1. The mapping pairs array actually
    621 *	  uses a delta_lcn value length of 0, i.e. delta_lcn is not present at
    622 *	  all, which is then interpreted by the driver as lcn = -1.
    623 *	  NOTE: Even uncompressed files can be sparse on NTFS 3.0 volumes, then
    624 *	  the same principles apply as above, except that the length is not
    625 *	  restricted to being any particular value.
    626 *
    627 *   2) The data in the block is not compressed:
    628 *	  This happens when compression doesn't reduce the size of the block
    629 *	  in clusters. I.e. if compression has a small effect so that the
    630 *	  compressed data still occupies X clusters, then the uncompressed data
    631 *	  is stored in the block.
    632 *	  This case is recognised by the fact that the runlist entry has
    633 *	  length = X and lcn >= 0. The mapping pairs array stores this as
    634 *	  normal with a run length of X and some specific delta_lcn, i.e.
    635 *	  delta_lcn has to be present.
    636 *
    637 *   3) The data in the block is compressed:
    638 *	  The common case. This case is recognised by the fact that the run
    639 *	  list entry has length L < X and lcn >= 0. The mapping pairs array
    640 *	  stores this as normal with a run length of X and some specific
    641 *	  delta_lcn, i.e. delta_lcn has to be present. This runlist entry is
    642 *	  immediately followed by a sparse entry with length = X - L and
    643 *	  lcn = -1. The latter entry is to make up the vcn counting to the
    644 *	  full compression block size X.
    645 *
    646 * In fact, life is more complicated because adjacent entries of the same type
    647 * can be coalesced. This means that one has to keep track of the number of
    648 * clusters handled and work on a basis of X clusters at a time being one
    649 * block. An example: if length L > X this means that this particular runlist
    650 * entry contains a block of length X and part of one or more blocks of length
    651 * L - X. Another example: if length L < X, this does not necessarily mean that
    652 * the block is compressed as it might be that the lcn changes inside the block
    653 * and hence the following runlist entry describes the continuation of the
    654 * potentially compressed block. The block would be compressed if the
    655 * following runlist entry describes at least X - L sparse clusters, thus
    656 * making up the compression block length as described in point 3 above. (Of
    657 * course, there can be several runlist entries with small lengths so that the
    658 * sparse entry does not follow the first data containing entry with
    659 * length < X.)
    660 *
    661 * NOTE: At the end of the compressed attribute value, there most likely is not
    662 * just the right amount of data to make up a compression block, thus this data
    663 * is not even attempted to be compressed. It is just stored as is, unless
    664 * the number of clusters it occupies is reduced when compressed in which case
    665 * it is stored as a compressed compression block, complete with sparse
    666 * clusters at the end.
    667 */
    668
    669/*
    670 * Flags of resident attributes (8-bit).
    671 */
    672enum {
    673	RESIDENT_ATTR_IS_INDEXED = 0x01, /* Attribute is referenced in an index
    674					    (has implications for deleting and
    675					    modifying the attribute). */
    676} __attribute__ ((__packed__));
    677
    678typedef u8 RESIDENT_ATTR_FLAGS;
    679
    680/*
    681 * Attribute record header. Always aligned to 8-byte boundary.
    682 */
    683typedef struct {
    684/*Ofs*/
    685/*  0*/	ATTR_TYPE type;		/* The (32-bit) type of the attribute. */
    686/*  4*/	le32 length;		/* Byte size of the resident part of the
    687				   attribute (aligned to 8-byte boundary).
    688				   Used to get to the next attribute. */
    689/*  8*/	u8 non_resident;	/* If 0, attribute is resident.
    690				   If 1, attribute is non-resident. */
    691/*  9*/	u8 name_length;		/* Unicode character size of name of attribute.
    692				   0 if unnamed. */
    693/* 10*/	le16 name_offset;	/* If name_length != 0, the byte offset to the
    694				   beginning of the name from the attribute
    695				   record. Note that the name is stored as a
    696				   Unicode string. When creating, place offset
    697				   just at the end of the record header. Then,
    698				   follow with attribute value or mapping pairs
    699				   array, resident and non-resident attributes
    700				   respectively, aligning to an 8-byte
    701				   boundary. */
    702/* 12*/	ATTR_FLAGS flags;	/* Flags describing the attribute. */
    703/* 14*/	le16 instance;		/* The instance of this attribute record. This
    704				   number is unique within this mft record (see
    705				   MFT_RECORD/next_attribute_instance notes in
    706				   mft.h for more details). */
    707/* 16*/	union {
    708		/* Resident attributes. */
    709		struct {
    710/* 16 */		le32 value_length;/* Byte size of attribute value. */
    711/* 20 */		le16 value_offset;/* Byte offset of the attribute
    712					     value from the start of the
    713					     attribute record. When creating,
    714					     align to 8-byte boundary if we
    715					     have a name present as this might
    716					     not have a length of a multiple
    717					     of 8-bytes. */
    718/* 22 */		RESIDENT_ATTR_FLAGS flags; /* See above. */
    719/* 23 */		s8 reserved;	  /* Reserved/alignment to 8-byte
    720					     boundary. */
    721		} __attribute__ ((__packed__)) resident;
    722		/* Non-resident attributes. */
    723		struct {
    724/* 16*/			leVCN lowest_vcn;/* Lowest valid virtual cluster number
    725				for this portion of the attribute value or
    726				0 if this is the only extent (usually the
    727				case). - Only when an attribute list is used
    728				does lowest_vcn != 0 ever occur. */
    729/* 24*/			leVCN highest_vcn;/* Highest valid vcn of this extent of
    730				the attribute value. - Usually there is only one
    731				portion, so this usually equals the attribute
    732				value size in clusters minus 1. Can be -1 for
    733				zero length files. Can be 0 for "single extent"
    734				attributes. */
    735/* 32*/			le16 mapping_pairs_offset; /* Byte offset from the
    736				beginning of the structure to the mapping pairs
    737				array which contains the mappings between the
    738				vcns and the logical cluster numbers (lcns).
    739				When creating, place this at the end of this
    740				record header aligned to 8-byte boundary. */
    741/* 34*/			u8 compression_unit; /* The compression unit expressed
    742				as the log to the base 2 of the number of
    743				clusters in a compression unit.  0 means not
    744				compressed.  (This effectively limits the
    745				compression unit size to be a power of two
    746				clusters.)  WinNT4 only uses a value of 4.
    747				Sparse files have this set to 0 on XPSP2. */
    748/* 35*/			u8 reserved[5];		/* Align to 8-byte boundary. */
    749/* The sizes below are only used when lowest_vcn is zero, as otherwise it would
    750   be difficult to keep them up-to-date.*/
    751/* 40*/			sle64 allocated_size;	/* Byte size of disk space
    752				allocated to hold the attribute value. Always
    753				is a multiple of the cluster size. When a file
    754				is compressed, this field is a multiple of the
    755				compression block size (2^compression_unit) and
    756				it represents the logically allocated space
    757				rather than the actual on disk usage. For this
    758				use the compressed_size (see below). */
    759/* 48*/			sle64 data_size;	/* Byte size of the attribute
    760				value. Can be larger than allocated_size if
    761				attribute value is compressed or sparse. */
    762/* 56*/			sle64 initialized_size;	/* Byte size of initialized
    763				portion of the attribute value. Usually equals
    764				data_size. */
    765/* sizeof(uncompressed attr) = 64*/
    766/* 64*/			sle64 compressed_size;	/* Byte size of the attribute
    767				value after compression.  Only present when
    768				compressed or sparse.  Always is a multiple of
    769				the cluster size.  Represents the actual amount
    770				of disk space being used on the disk. */
    771/* sizeof(compressed attr) = 72*/
    772		} __attribute__ ((__packed__)) non_resident;
    773	} __attribute__ ((__packed__)) data;
    774} __attribute__ ((__packed__)) ATTR_RECORD;
    775
    776typedef ATTR_RECORD ATTR_REC;
    777
    778/*
    779 * File attribute flags (32-bit) appearing in the file_attributes fields of the
    780 * STANDARD_INFORMATION attribute of MFT_RECORDs and the FILENAME_ATTR
    781 * attributes of MFT_RECORDs and directory index entries.
    782 *
    783 * All of the below flags appear in the directory index entries but only some
    784 * appear in the STANDARD_INFORMATION attribute whilst only some others appear
    785 * in the FILENAME_ATTR attribute of MFT_RECORDs.  Unless otherwise stated the
    786 * flags appear in all of the above.
    787 */
    788enum {
    789	FILE_ATTR_READONLY		= cpu_to_le32(0x00000001),
    790	FILE_ATTR_HIDDEN		= cpu_to_le32(0x00000002),
    791	FILE_ATTR_SYSTEM		= cpu_to_le32(0x00000004),
    792	/* Old DOS volid. Unused in NT.	= cpu_to_le32(0x00000008), */
    793
    794	FILE_ATTR_DIRECTORY		= cpu_to_le32(0x00000010),
    795	/* Note, FILE_ATTR_DIRECTORY is not considered valid in NT.  It is
    796	   reserved for the DOS SUBDIRECTORY flag. */
    797	FILE_ATTR_ARCHIVE		= cpu_to_le32(0x00000020),
    798	FILE_ATTR_DEVICE		= cpu_to_le32(0x00000040),
    799	FILE_ATTR_NORMAL		= cpu_to_le32(0x00000080),
    800
    801	FILE_ATTR_TEMPORARY		= cpu_to_le32(0x00000100),
    802	FILE_ATTR_SPARSE_FILE		= cpu_to_le32(0x00000200),
    803	FILE_ATTR_REPARSE_POINT		= cpu_to_le32(0x00000400),
    804	FILE_ATTR_COMPRESSED		= cpu_to_le32(0x00000800),
    805
    806	FILE_ATTR_OFFLINE		= cpu_to_le32(0x00001000),
    807	FILE_ATTR_NOT_CONTENT_INDEXED	= cpu_to_le32(0x00002000),
    808	FILE_ATTR_ENCRYPTED		= cpu_to_le32(0x00004000),
    809
    810	FILE_ATTR_VALID_FLAGS		= cpu_to_le32(0x00007fb7),
    811	/* Note, FILE_ATTR_VALID_FLAGS masks out the old DOS VolId and the
    812	   FILE_ATTR_DEVICE and preserves everything else.  This mask is used
    813	   to obtain all flags that are valid for reading. */
    814	FILE_ATTR_VALID_SET_FLAGS	= cpu_to_le32(0x000031a7),
    815	/* Note, FILE_ATTR_VALID_SET_FLAGS masks out the old DOS VolId, the
    816	   F_A_DEVICE, F_A_DIRECTORY, F_A_SPARSE_FILE, F_A_REPARSE_POINT,
    817	   F_A_COMPRESSED, and F_A_ENCRYPTED and preserves the rest.  This mask
    818	   is used to obtain all flags that are valid for setting. */
    819	/*
    820	 * The flag FILE_ATTR_DUP_FILENAME_INDEX_PRESENT is present in all
    821	 * FILENAME_ATTR attributes but not in the STANDARD_INFORMATION
    822	 * attribute of an mft record.
    823	 */
    824	FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT	= cpu_to_le32(0x10000000),
    825	/* Note, this is a copy of the corresponding bit from the mft record,
    826	   telling us whether this is a directory or not, i.e. whether it has
    827	   an index root attribute or not. */
    828	FILE_ATTR_DUP_VIEW_INDEX_PRESENT	= cpu_to_le32(0x20000000),
    829	/* Note, this is a copy of the corresponding bit from the mft record,
    830	   telling us whether this file has a view index present (eg. object id
    831	   index, quota index, one of the security indexes or the encrypting
    832	   filesystem related indexes). */
    833};
    834
    835typedef le32 FILE_ATTR_FLAGS;
    836
    837/*
    838 * NOTE on times in NTFS: All times are in MS standard time format, i.e. they
    839 * are the number of 100-nanosecond intervals since 1st January 1601, 00:00:00
    840 * universal coordinated time (UTC). (In Linux time starts 1st January 1970,
    841 * 00:00:00 UTC and is stored as the number of 1-second intervals since then.)
    842 */
    843
    844/*
    845 * Attribute: Standard information (0x10).
    846 *
    847 * NOTE: Always resident.
    848 * NOTE: Present in all base file records on a volume.
    849 * NOTE: There is conflicting information about the meaning of each of the time
    850 *	 fields but the meaning as defined below has been verified to be
    851 *	 correct by practical experimentation on Windows NT4 SP6a and is hence
    852 *	 assumed to be the one and only correct interpretation.
    853 */
    854typedef struct {
    855/*Ofs*/
    856/*  0*/	sle64 creation_time;		/* Time file was created. Updated when
    857					   a filename is changed(?). */
    858/*  8*/	sle64 last_data_change_time;	/* Time the data attribute was last
    859					   modified. */
    860/* 16*/	sle64 last_mft_change_time;	/* Time this mft record was last
    861					   modified. */
    862/* 24*/	sle64 last_access_time;		/* Approximate time when the file was
    863					   last accessed (obviously this is not
    864					   updated on read-only volumes). In
    865					   Windows this is only updated when
    866					   accessed if some time delta has
    867					   passed since the last update. Also,
    868					   last access time updates can be
    869					   disabled altogether for speed. */
    870/* 32*/	FILE_ATTR_FLAGS file_attributes; /* Flags describing the file. */
    871/* 36*/	union {
    872	/* NTFS 1.2 */
    873		struct {
    874		/* 36*/	u8 reserved12[12];	/* Reserved/alignment to 8-byte
    875						   boundary. */
    876		} __attribute__ ((__packed__)) v1;
    877	/* sizeof() = 48 bytes */
    878	/* NTFS 3.x */
    879		struct {
    880/*
    881 * If a volume has been upgraded from a previous NTFS version, then these
    882 * fields are present only if the file has been accessed since the upgrade.
    883 * Recognize the difference by comparing the length of the resident attribute
    884 * value. If it is 48, then the following fields are missing. If it is 72 then
    885 * the fields are present. Maybe just check like this:
    886 *	if (resident.ValueLength < sizeof(STANDARD_INFORMATION)) {
    887 *		Assume NTFS 1.2- format.
    888 *		If (volume version is 3.x)
    889 *			Upgrade attribute to NTFS 3.x format.
    890 *		else
    891 *			Use NTFS 1.2- format for access.
    892 *	} else
    893 *		Use NTFS 3.x format for access.
    894 * Only problem is that it might be legal to set the length of the value to
    895 * arbitrarily large values thus spoiling this check. - But chkdsk probably
    896 * views that as a corruption, assuming that it behaves like this for all
    897 * attributes.
    898 */
    899		/* 36*/	le32 maximum_versions;	/* Maximum allowed versions for
    900				file. Zero if version numbering is disabled. */
    901		/* 40*/	le32 version_number;	/* This file's version (if any).
    902				Set to zero if maximum_versions is zero. */
    903		/* 44*/	le32 class_id;		/* Class id from bidirectional
    904				class id index (?). */
    905		/* 48*/	le32 owner_id;		/* Owner_id of the user owning
    906				the file. Translate via $Q index in FILE_Extend
    907				/$Quota to the quota control entry for the user
    908				owning the file. Zero if quotas are disabled. */
    909		/* 52*/	le32 security_id;	/* Security_id for the file.
    910				Translate via $SII index and $SDS data stream
    911				in FILE_Secure to the security descriptor. */
    912		/* 56*/	le64 quota_charged;	/* Byte size of the charge to
    913				the quota for all streams of the file. Note: Is
    914				zero if quotas are disabled. */
    915		/* 64*/	leUSN usn;		/* Last update sequence number
    916				of the file.  This is a direct index into the
    917				transaction log file ($UsnJrnl).  It is zero if
    918				the usn journal is disabled or this file has
    919				not been subject to logging yet.  See usnjrnl.h
    920				for details. */
    921		} __attribute__ ((__packed__)) v3;
    922	/* sizeof() = 72 bytes (NTFS 3.x) */
    923	} __attribute__ ((__packed__)) ver;
    924} __attribute__ ((__packed__)) STANDARD_INFORMATION;
    925
    926/*
    927 * Attribute: Attribute list (0x20).
    928 *
    929 * - Can be either resident or non-resident.
    930 * - Value consists of a sequence of variable length, 8-byte aligned,
    931 * ATTR_LIST_ENTRY records.
    932 * - The list is not terminated by anything at all! The only way to know when
    933 * the end is reached is to keep track of the current offset and compare it to
    934 * the attribute value size.
    935 * - The attribute list attribute contains one entry for each attribute of
    936 * the file in which the list is located, except for the list attribute
    937 * itself. The list is sorted: first by attribute type, second by attribute
    938 * name (if present), third by instance number. The extents of one
    939 * non-resident attribute (if present) immediately follow after the initial
    940 * extent. They are ordered by lowest_vcn and have their instace set to zero.
    941 * It is not allowed to have two attributes with all sorting keys equal.
    942 * - Further restrictions:
    943 *	- If not resident, the vcn to lcn mapping array has to fit inside the
    944 *	  base mft record.
    945 *	- The attribute list attribute value has a maximum size of 256kb. This
    946 *	  is imposed by the Windows cache manager.
    947 * - Attribute lists are only used when the attributes of mft record do not
    948 * fit inside the mft record despite all attributes (that can be made
    949 * non-resident) having been made non-resident. This can happen e.g. when:
    950 *	- File has a large number of hard links (lots of file name
    951 *	  attributes present).
    952 *	- The mapping pairs array of some non-resident attribute becomes so
    953 *	  large due to fragmentation that it overflows the mft record.
    954 *	- The security descriptor is very complex (not applicable to
    955 *	  NTFS 3.0 volumes).
    956 *	- There are many named streams.
    957 */
    958typedef struct {
    959/*Ofs*/
    960/*  0*/	ATTR_TYPE type;		/* Type of referenced attribute. */
    961/*  4*/	le16 length;		/* Byte size of this entry (8-byte aligned). */
    962/*  6*/	u8 name_length;		/* Size in Unicode chars of the name of the
    963				   attribute or 0 if unnamed. */
    964/*  7*/	u8 name_offset;		/* Byte offset to beginning of attribute name
    965				   (always set this to where the name would
    966				   start even if unnamed). */
    967/*  8*/	leVCN lowest_vcn;	/* Lowest virtual cluster number of this portion
    968				   of the attribute value. This is usually 0. It
    969				   is non-zero for the case where one attribute
    970				   does not fit into one mft record and thus
    971				   several mft records are allocated to hold
    972				   this attribute. In the latter case, each mft
    973				   record holds one extent of the attribute and
    974				   there is one attribute list entry for each
    975				   extent. NOTE: This is DEFINITELY a signed
    976				   value! The windows driver uses cmp, followed
    977				   by jg when comparing this, thus it treats it
    978				   as signed. */
    979/* 16*/	leMFT_REF mft_reference;/* The reference of the mft record holding
    980				   the ATTR_RECORD for this portion of the
    981				   attribute value. */
    982/* 24*/	le16 instance;		/* If lowest_vcn = 0, the instance of the
    983				   attribute being referenced; otherwise 0. */
    984/* 26*/	ntfschar name[0];	/* Use when creating only. When reading use
    985				   name_offset to determine the location of the
    986				   name. */
    987/* sizeof() = 26 + (attribute_name_length * 2) bytes */
    988} __attribute__ ((__packed__)) ATTR_LIST_ENTRY;
    989
    990/*
    991 * The maximum allowed length for a file name.
    992 */
    993#define MAXIMUM_FILE_NAME_LENGTH	255
    994
    995/*
    996 * Possible namespaces for filenames in ntfs (8-bit).
    997 */
    998enum {
    999	FILE_NAME_POSIX		= 0x00,
   1000	/* This is the largest namespace. It is case sensitive and allows all
   1001	   Unicode characters except for: '\0' and '/'.  Beware that in
   1002	   WinNT/2k/2003 by default files which eg have the same name except
   1003	   for their case will not be distinguished by the standard utilities
   1004	   and thus a "del filename" will delete both "filename" and "fileName"
   1005	   without warning.  However if for example Services For Unix (SFU) are
   1006	   installed and the case sensitive option was enabled at installation
   1007	   time, then you can create/access/delete such files.
   1008	   Note that even SFU places restrictions on the filenames beyond the
   1009	   '\0' and '/' and in particular the following set of characters is
   1010	   not allowed: '"', '/', '<', '>', '\'.  All other characters,
   1011	   including the ones no allowed in WIN32 namespace are allowed.
   1012	   Tested with SFU 3.5 (this is now free) running on Windows XP. */
   1013	FILE_NAME_WIN32		= 0x01,
   1014	/* The standard WinNT/2k NTFS long filenames. Case insensitive.  All
   1015	   Unicode chars except: '\0', '"', '*', '/', ':', '<', '>', '?', '\',
   1016	   and '|'.  Further, names cannot end with a '.' or a space. */
   1017	FILE_NAME_DOS		= 0x02,
   1018	/* The standard DOS filenames (8.3 format). Uppercase only.  All 8-bit
   1019	   characters greater space, except: '"', '*', '+', ',', '/', ':', ';',
   1020	   '<', '=', '>', '?', and '\'. */
   1021	FILE_NAME_WIN32_AND_DOS	= 0x03,
   1022	/* 3 means that both the Win32 and the DOS filenames are identical and
   1023	   hence have been saved in this single filename record. */
   1024} __attribute__ ((__packed__));
   1025
   1026typedef u8 FILE_NAME_TYPE_FLAGS;
   1027
   1028/*
   1029 * Attribute: Filename (0x30).
   1030 *
   1031 * NOTE: Always resident.
   1032 * NOTE: All fields, except the parent_directory, are only updated when the
   1033 *	 filename is changed. Until then, they just become out of sync with
   1034 *	 reality and the more up to date values are present in the standard
   1035 *	 information attribute.
   1036 * NOTE: There is conflicting information about the meaning of each of the time
   1037 *	 fields but the meaning as defined below has been verified to be
   1038 *	 correct by practical experimentation on Windows NT4 SP6a and is hence
   1039 *	 assumed to be the one and only correct interpretation.
   1040 */
   1041typedef struct {
   1042/*hex ofs*/
   1043/*  0*/	leMFT_REF parent_directory;	/* Directory this filename is
   1044					   referenced from. */
   1045/*  8*/	sle64 creation_time;		/* Time file was created. */
   1046/* 10*/	sle64 last_data_change_time;	/* Time the data attribute was last
   1047					   modified. */
   1048/* 18*/	sle64 last_mft_change_time;	/* Time this mft record was last
   1049					   modified. */
   1050/* 20*/	sle64 last_access_time;		/* Time this mft record was last
   1051					   accessed. */
   1052/* 28*/	sle64 allocated_size;		/* Byte size of on-disk allocated space
   1053					   for the unnamed data attribute.  So
   1054					   for normal $DATA, this is the
   1055					   allocated_size from the unnamed
   1056					   $DATA attribute and for compressed
   1057					   and/or sparse $DATA, this is the
   1058					   compressed_size from the unnamed
   1059					   $DATA attribute.  For a directory or
   1060					   other inode without an unnamed $DATA
   1061					   attribute, this is always 0.  NOTE:
   1062					   This is a multiple of the cluster
   1063					   size. */
   1064/* 30*/	sle64 data_size;		/* Byte size of actual data in unnamed
   1065					   data attribute.  For a directory or
   1066					   other inode without an unnamed $DATA
   1067					   attribute, this is always 0. */
   1068/* 38*/	FILE_ATTR_FLAGS file_attributes;	/* Flags describing the file. */
   1069/* 3c*/	union {
   1070	/* 3c*/	struct {
   1071		/* 3c*/	le16 packed_ea_size;	/* Size of the buffer needed to
   1072						   pack the extended attributes
   1073						   (EAs), if such are present.*/
   1074		/* 3e*/	le16 reserved;		/* Reserved for alignment. */
   1075		} __attribute__ ((__packed__)) ea;
   1076	/* 3c*/	struct {
   1077		/* 3c*/	le32 reparse_point_tag;	/* Type of reparse point,
   1078						   present only in reparse
   1079						   points and only if there are
   1080						   no EAs. */
   1081		} __attribute__ ((__packed__)) rp;
   1082	} __attribute__ ((__packed__)) type;
   1083/* 40*/	u8 file_name_length;			/* Length of file name in
   1084						   (Unicode) characters. */
   1085/* 41*/	FILE_NAME_TYPE_FLAGS file_name_type;	/* Namespace of the file name.*/
   1086/* 42*/	ntfschar file_name[0];			/* File name in Unicode. */
   1087} __attribute__ ((__packed__)) FILE_NAME_ATTR;
   1088
   1089/*
   1090 * GUID structures store globally unique identifiers (GUID). A GUID is a
   1091 * 128-bit value consisting of one group of eight hexadecimal digits, followed
   1092 * by three groups of four hexadecimal digits each, followed by one group of
   1093 * twelve hexadecimal digits. GUIDs are Microsoft's implementation of the
   1094 * distributed computing environment (DCE) universally unique identifier (UUID).
   1095 * Example of a GUID:
   1096 *	1F010768-5A73-BC91-0010A52216A7
   1097 */
   1098typedef struct {
   1099	le32 data1;	/* The first eight hexadecimal digits of the GUID. */
   1100	le16 data2;	/* The first group of four hexadecimal digits. */
   1101	le16 data3;	/* The second group of four hexadecimal digits. */
   1102	u8 data4[8];	/* The first two bytes are the third group of four
   1103			   hexadecimal digits. The remaining six bytes are the
   1104			   final 12 hexadecimal digits. */
   1105} __attribute__ ((__packed__)) GUID;
   1106
   1107/*
   1108 * FILE_Extend/$ObjId contains an index named $O. This index contains all
   1109 * object_ids present on the volume as the index keys and the corresponding
   1110 * mft_record numbers as the index entry data parts. The data part (defined
   1111 * below) also contains three other object_ids:
   1112 *	birth_volume_id - object_id of FILE_Volume on which the file was first
   1113 *			  created. Optional (i.e. can be zero).
   1114 *	birth_object_id - object_id of file when it was first created. Usually
   1115 *			  equals the object_id. Optional (i.e. can be zero).
   1116 *	domain_id	- Reserved (always zero).
   1117 */
   1118typedef struct {
   1119	leMFT_REF mft_reference;/* Mft record containing the object_id in
   1120				   the index entry key. */
   1121	union {
   1122		struct {
   1123			GUID birth_volume_id;
   1124			GUID birth_object_id;
   1125			GUID domain_id;
   1126		} __attribute__ ((__packed__)) origin;
   1127		u8 extended_info[48];
   1128	} __attribute__ ((__packed__)) opt;
   1129} __attribute__ ((__packed__)) OBJ_ID_INDEX_DATA;
   1130
   1131/*
   1132 * Attribute: Object id (NTFS 3.0+) (0x40).
   1133 *
   1134 * NOTE: Always resident.
   1135 */
   1136typedef struct {
   1137	GUID object_id;				/* Unique id assigned to the
   1138						   file.*/
   1139	/* The following fields are optional. The attribute value size is 16
   1140	   bytes, i.e. sizeof(GUID), if these are not present at all. Note,
   1141	   the entries can be present but one or more (or all) can be zero
   1142	   meaning that that particular value(s) is(are) not defined. */
   1143	union {
   1144		struct {
   1145			GUID birth_volume_id;	/* Unique id of volume on which
   1146						   the file was first created.*/
   1147			GUID birth_object_id;	/* Unique id of file when it was
   1148						   first created. */
   1149			GUID domain_id;		/* Reserved, zero. */
   1150		} __attribute__ ((__packed__)) origin;
   1151		u8 extended_info[48];
   1152	} __attribute__ ((__packed__)) opt;
   1153} __attribute__ ((__packed__)) OBJECT_ID_ATTR;
   1154
   1155/*
   1156 * The pre-defined IDENTIFIER_AUTHORITIES used as SID_IDENTIFIER_AUTHORITY in
   1157 * the SID structure (see below).
   1158 */
   1159//typedef enum {					/* SID string prefix. */
   1160//	SECURITY_NULL_SID_AUTHORITY	= {0, 0, 0, 0, 0, 0},	/* S-1-0 */
   1161//	SECURITY_WORLD_SID_AUTHORITY	= {0, 0, 0, 0, 0, 1},	/* S-1-1 */
   1162//	SECURITY_LOCAL_SID_AUTHORITY	= {0, 0, 0, 0, 0, 2},	/* S-1-2 */
   1163//	SECURITY_CREATOR_SID_AUTHORITY	= {0, 0, 0, 0, 0, 3},	/* S-1-3 */
   1164//	SECURITY_NON_UNIQUE_AUTHORITY	= {0, 0, 0, 0, 0, 4},	/* S-1-4 */
   1165//	SECURITY_NT_SID_AUTHORITY	= {0, 0, 0, 0, 0, 5},	/* S-1-5 */
   1166//} IDENTIFIER_AUTHORITIES;
   1167
   1168/*
   1169 * These relative identifiers (RIDs) are used with the above identifier
   1170 * authorities to make up universal well-known SIDs.
   1171 *
   1172 * Note: The relative identifier (RID) refers to the portion of a SID, which
   1173 * identifies a user or group in relation to the authority that issued the SID.
   1174 * For example, the universal well-known SID Creator Owner ID (S-1-3-0) is
   1175 * made up of the identifier authority SECURITY_CREATOR_SID_AUTHORITY (3) and
   1176 * the relative identifier SECURITY_CREATOR_OWNER_RID (0).
   1177 */
   1178typedef enum {					/* Identifier authority. */
   1179	SECURITY_NULL_RID		  = 0,	/* S-1-0 */
   1180	SECURITY_WORLD_RID		  = 0,	/* S-1-1 */
   1181	SECURITY_LOCAL_RID		  = 0,	/* S-1-2 */
   1182
   1183	SECURITY_CREATOR_OWNER_RID	  = 0,	/* S-1-3 */
   1184	SECURITY_CREATOR_GROUP_RID	  = 1,	/* S-1-3 */
   1185
   1186	SECURITY_CREATOR_OWNER_SERVER_RID = 2,	/* S-1-3 */
   1187	SECURITY_CREATOR_GROUP_SERVER_RID = 3,	/* S-1-3 */
   1188
   1189	SECURITY_DIALUP_RID		  = 1,
   1190	SECURITY_NETWORK_RID		  = 2,
   1191	SECURITY_BATCH_RID		  = 3,
   1192	SECURITY_INTERACTIVE_RID	  = 4,
   1193	SECURITY_SERVICE_RID		  = 6,
   1194	SECURITY_ANONYMOUS_LOGON_RID	  = 7,
   1195	SECURITY_PROXY_RID		  = 8,
   1196	SECURITY_ENTERPRISE_CONTROLLERS_RID=9,
   1197	SECURITY_SERVER_LOGON_RID	  = 9,
   1198	SECURITY_PRINCIPAL_SELF_RID	  = 0xa,
   1199	SECURITY_AUTHENTICATED_USER_RID	  = 0xb,
   1200	SECURITY_RESTRICTED_CODE_RID	  = 0xc,
   1201	SECURITY_TERMINAL_SERVER_RID	  = 0xd,
   1202
   1203	SECURITY_LOGON_IDS_RID		  = 5,
   1204	SECURITY_LOGON_IDS_RID_COUNT	  = 3,
   1205
   1206	SECURITY_LOCAL_SYSTEM_RID	  = 0x12,
   1207
   1208	SECURITY_NT_NON_UNIQUE		  = 0x15,
   1209
   1210	SECURITY_BUILTIN_DOMAIN_RID	  = 0x20,
   1211
   1212	/*
   1213	 * Well-known domain relative sub-authority values (RIDs).
   1214	 */
   1215
   1216	/* Users. */
   1217	DOMAIN_USER_RID_ADMIN		  = 0x1f4,
   1218	DOMAIN_USER_RID_GUEST		  = 0x1f5,
   1219	DOMAIN_USER_RID_KRBTGT		  = 0x1f6,
   1220
   1221	/* Groups. */
   1222	DOMAIN_GROUP_RID_ADMINS		  = 0x200,
   1223	DOMAIN_GROUP_RID_USERS		  = 0x201,
   1224	DOMAIN_GROUP_RID_GUESTS		  = 0x202,
   1225	DOMAIN_GROUP_RID_COMPUTERS	  = 0x203,
   1226	DOMAIN_GROUP_RID_CONTROLLERS	  = 0x204,
   1227	DOMAIN_GROUP_RID_CERT_ADMINS	  = 0x205,
   1228	DOMAIN_GROUP_RID_SCHEMA_ADMINS	  = 0x206,
   1229	DOMAIN_GROUP_RID_ENTERPRISE_ADMINS= 0x207,
   1230	DOMAIN_GROUP_RID_POLICY_ADMINS	  = 0x208,
   1231
   1232	/* Aliases. */
   1233	DOMAIN_ALIAS_RID_ADMINS		  = 0x220,
   1234	DOMAIN_ALIAS_RID_USERS		  = 0x221,
   1235	DOMAIN_ALIAS_RID_GUESTS		  = 0x222,
   1236	DOMAIN_ALIAS_RID_POWER_USERS	  = 0x223,
   1237
   1238	DOMAIN_ALIAS_RID_ACCOUNT_OPS	  = 0x224,
   1239	DOMAIN_ALIAS_RID_SYSTEM_OPS	  = 0x225,
   1240	DOMAIN_ALIAS_RID_PRINT_OPS	  = 0x226,
   1241	DOMAIN_ALIAS_RID_BACKUP_OPS	  = 0x227,
   1242
   1243	DOMAIN_ALIAS_RID_REPLICATOR	  = 0x228,
   1244	DOMAIN_ALIAS_RID_RAS_SERVERS	  = 0x229,
   1245	DOMAIN_ALIAS_RID_PREW2KCOMPACCESS = 0x22a,
   1246} RELATIVE_IDENTIFIERS;
   1247
   1248/*
   1249 * The universal well-known SIDs:
   1250 *
   1251 *	NULL_SID			S-1-0-0
   1252 *	WORLD_SID			S-1-1-0
   1253 *	LOCAL_SID			S-1-2-0
   1254 *	CREATOR_OWNER_SID		S-1-3-0
   1255 *	CREATOR_GROUP_SID		S-1-3-1
   1256 *	CREATOR_OWNER_SERVER_SID	S-1-3-2
   1257 *	CREATOR_GROUP_SERVER_SID	S-1-3-3
   1258 *
   1259 *	(Non-unique IDs)		S-1-4
   1260 *
   1261 * NT well-known SIDs:
   1262 *
   1263 *	NT_AUTHORITY_SID	S-1-5
   1264 *	DIALUP_SID		S-1-5-1
   1265 *
   1266 *	NETWORD_SID		S-1-5-2
   1267 *	BATCH_SID		S-1-5-3
   1268 *	INTERACTIVE_SID		S-1-5-4
   1269 *	SERVICE_SID		S-1-5-6
   1270 *	ANONYMOUS_LOGON_SID	S-1-5-7		(aka null logon session)
   1271 *	PROXY_SID		S-1-5-8
   1272 *	SERVER_LOGON_SID	S-1-5-9		(aka domain controller account)
   1273 *	SELF_SID		S-1-5-10	(self RID)
   1274 *	AUTHENTICATED_USER_SID	S-1-5-11
   1275 *	RESTRICTED_CODE_SID	S-1-5-12	(running restricted code)
   1276 *	TERMINAL_SERVER_SID	S-1-5-13	(running on terminal server)
   1277 *
   1278 *	(Logon IDs)		S-1-5-5-X-Y
   1279 *
   1280 *	(NT non-unique IDs)	S-1-5-0x15-...
   1281 *
   1282 *	(Built-in domain)	S-1-5-0x20
   1283 */
   1284
   1285/*
   1286 * The SID_IDENTIFIER_AUTHORITY is a 48-bit value used in the SID structure.
   1287 *
   1288 * NOTE: This is stored as a big endian number, hence the high_part comes
   1289 * before the low_part.
   1290 */
   1291typedef union {
   1292	struct {
   1293		u16 high_part;	/* High 16-bits. */
   1294		u32 low_part;	/* Low 32-bits. */
   1295	} __attribute__ ((__packed__)) parts;
   1296	u8 value[6];		/* Value as individual bytes. */
   1297} __attribute__ ((__packed__)) SID_IDENTIFIER_AUTHORITY;
   1298
   1299/*
   1300 * The SID structure is a variable-length structure used to uniquely identify
   1301 * users or groups. SID stands for security identifier.
   1302 *
   1303 * The standard textual representation of the SID is of the form:
   1304 *	S-R-I-S-S...
   1305 * Where:
   1306 *    - The first "S" is the literal character 'S' identifying the following
   1307 *	digits as a SID.
   1308 *    - R is the revision level of the SID expressed as a sequence of digits
   1309 *	either in decimal or hexadecimal (if the later, prefixed by "0x").
   1310 *    - I is the 48-bit identifier_authority, expressed as digits as R above.
   1311 *    - S... is one or more sub_authority values, expressed as digits as above.
   1312 *
   1313 * Example SID; the domain-relative SID of the local Administrators group on
   1314 * Windows NT/2k:
   1315 *	S-1-5-32-544
   1316 * This translates to a SID with:
   1317 *	revision = 1,
   1318 *	sub_authority_count = 2,
   1319 *	identifier_authority = {0,0,0,0,0,5},	// SECURITY_NT_AUTHORITY
   1320 *	sub_authority[0] = 32,			// SECURITY_BUILTIN_DOMAIN_RID
   1321 *	sub_authority[1] = 544			// DOMAIN_ALIAS_RID_ADMINS
   1322 */
   1323typedef struct {
   1324	u8 revision;
   1325	u8 sub_authority_count;
   1326	SID_IDENTIFIER_AUTHORITY identifier_authority;
   1327	le32 sub_authority[1];		/* At least one sub_authority. */
   1328} __attribute__ ((__packed__)) SID;
   1329
   1330/*
   1331 * Current constants for SIDs.
   1332 */
   1333typedef enum {
   1334	SID_REVISION			=  1,	/* Current revision level. */
   1335	SID_MAX_SUB_AUTHORITIES		= 15,	/* Maximum number of those. */
   1336	SID_RECOMMENDED_SUB_AUTHORITIES	=  1,	/* Will change to around 6 in
   1337						   a future revision. */
   1338} SID_CONSTANTS;
   1339
   1340/*
   1341 * The predefined ACE types (8-bit, see below).
   1342 */
   1343enum {
   1344	ACCESS_MIN_MS_ACE_TYPE		= 0,
   1345	ACCESS_ALLOWED_ACE_TYPE		= 0,
   1346	ACCESS_DENIED_ACE_TYPE		= 1,
   1347	SYSTEM_AUDIT_ACE_TYPE		= 2,
   1348	SYSTEM_ALARM_ACE_TYPE		= 3, /* Not implemented as of Win2k. */
   1349	ACCESS_MAX_MS_V2_ACE_TYPE	= 3,
   1350
   1351	ACCESS_ALLOWED_COMPOUND_ACE_TYPE= 4,
   1352	ACCESS_MAX_MS_V3_ACE_TYPE	= 4,
   1353
   1354	/* The following are Win2k only. */
   1355	ACCESS_MIN_MS_OBJECT_ACE_TYPE	= 5,
   1356	ACCESS_ALLOWED_OBJECT_ACE_TYPE	= 5,
   1357	ACCESS_DENIED_OBJECT_ACE_TYPE	= 6,
   1358	SYSTEM_AUDIT_OBJECT_ACE_TYPE	= 7,
   1359	SYSTEM_ALARM_OBJECT_ACE_TYPE	= 8,
   1360	ACCESS_MAX_MS_OBJECT_ACE_TYPE	= 8,
   1361
   1362	ACCESS_MAX_MS_V4_ACE_TYPE	= 8,
   1363
   1364	/* This one is for WinNT/2k. */
   1365	ACCESS_MAX_MS_ACE_TYPE		= 8,
   1366} __attribute__ ((__packed__));
   1367
   1368typedef u8 ACE_TYPES;
   1369
   1370/*
   1371 * The ACE flags (8-bit) for audit and inheritance (see below).
   1372 *
   1373 * SUCCESSFUL_ACCESS_ACE_FLAG is only used with system audit and alarm ACE
   1374 * types to indicate that a message is generated (in Windows!) for successful
   1375 * accesses.
   1376 *
   1377 * FAILED_ACCESS_ACE_FLAG is only used with system audit and alarm ACE types
   1378 * to indicate that a message is generated (in Windows!) for failed accesses.
   1379 */
   1380enum {
   1381	/* The inheritance flags. */
   1382	OBJECT_INHERIT_ACE		= 0x01,
   1383	CONTAINER_INHERIT_ACE		= 0x02,
   1384	NO_PROPAGATE_INHERIT_ACE	= 0x04,
   1385	INHERIT_ONLY_ACE		= 0x08,
   1386	INHERITED_ACE			= 0x10,	/* Win2k only. */
   1387	VALID_INHERIT_FLAGS		= 0x1f,
   1388
   1389	/* The audit flags. */
   1390	SUCCESSFUL_ACCESS_ACE_FLAG	= 0x40,
   1391	FAILED_ACCESS_ACE_FLAG		= 0x80,
   1392} __attribute__ ((__packed__));
   1393
   1394typedef u8 ACE_FLAGS;
   1395
   1396/*
   1397 * An ACE is an access-control entry in an access-control list (ACL).
   1398 * An ACE defines access to an object for a specific user or group or defines
   1399 * the types of access that generate system-administration messages or alarms
   1400 * for a specific user or group. The user or group is identified by a security
   1401 * identifier (SID).
   1402 *
   1403 * Each ACE starts with an ACE_HEADER structure (aligned on 4-byte boundary),
   1404 * which specifies the type and size of the ACE. The format of the subsequent
   1405 * data depends on the ACE type.
   1406 */
   1407typedef struct {
   1408/*Ofs*/
   1409/*  0*/	ACE_TYPES type;		/* Type of the ACE. */
   1410/*  1*/	ACE_FLAGS flags;	/* Flags describing the ACE. */
   1411/*  2*/	le16 size;		/* Size in bytes of the ACE. */
   1412} __attribute__ ((__packed__)) ACE_HEADER;
   1413
   1414/*
   1415 * The access mask (32-bit). Defines the access rights.
   1416 *
   1417 * The specific rights (bits 0 to 15).  These depend on the type of the object
   1418 * being secured by the ACE.
   1419 */
   1420enum {
   1421	/* Specific rights for files and directories are as follows: */
   1422
   1423	/* Right to read data from the file. (FILE) */
   1424	FILE_READ_DATA			= cpu_to_le32(0x00000001),
   1425	/* Right to list contents of a directory. (DIRECTORY) */
   1426	FILE_LIST_DIRECTORY		= cpu_to_le32(0x00000001),
   1427
   1428	/* Right to write data to the file. (FILE) */
   1429	FILE_WRITE_DATA			= cpu_to_le32(0x00000002),
   1430	/* Right to create a file in the directory. (DIRECTORY) */
   1431	FILE_ADD_FILE			= cpu_to_le32(0x00000002),
   1432
   1433	/* Right to append data to the file. (FILE) */
   1434	FILE_APPEND_DATA		= cpu_to_le32(0x00000004),
   1435	/* Right to create a subdirectory. (DIRECTORY) */
   1436	FILE_ADD_SUBDIRECTORY		= cpu_to_le32(0x00000004),
   1437
   1438	/* Right to read extended attributes. (FILE/DIRECTORY) */
   1439	FILE_READ_EA			= cpu_to_le32(0x00000008),
   1440
   1441	/* Right to write extended attributes. (FILE/DIRECTORY) */
   1442	FILE_WRITE_EA			= cpu_to_le32(0x00000010),
   1443
   1444	/* Right to execute a file. (FILE) */
   1445	FILE_EXECUTE			= cpu_to_le32(0x00000020),
   1446	/* Right to traverse the directory. (DIRECTORY) */
   1447	FILE_TRAVERSE			= cpu_to_le32(0x00000020),
   1448
   1449	/*
   1450	 * Right to delete a directory and all the files it contains (its
   1451	 * children), even if the files are read-only. (DIRECTORY)
   1452	 */
   1453	FILE_DELETE_CHILD		= cpu_to_le32(0x00000040),
   1454
   1455	/* Right to read file attributes. (FILE/DIRECTORY) */
   1456	FILE_READ_ATTRIBUTES		= cpu_to_le32(0x00000080),
   1457
   1458	/* Right to change file attributes. (FILE/DIRECTORY) */
   1459	FILE_WRITE_ATTRIBUTES		= cpu_to_le32(0x00000100),
   1460
   1461	/*
   1462	 * The standard rights (bits 16 to 23).  These are independent of the
   1463	 * type of object being secured.
   1464	 */
   1465
   1466	/* Right to delete the object. */
   1467	DELETE				= cpu_to_le32(0x00010000),
   1468
   1469	/*
   1470	 * Right to read the information in the object's security descriptor,
   1471	 * not including the information in the SACL, i.e. right to read the
   1472	 * security descriptor and owner.
   1473	 */
   1474	READ_CONTROL			= cpu_to_le32(0x00020000),
   1475
   1476	/* Right to modify the DACL in the object's security descriptor. */
   1477	WRITE_DAC			= cpu_to_le32(0x00040000),
   1478
   1479	/* Right to change the owner in the object's security descriptor. */
   1480	WRITE_OWNER			= cpu_to_le32(0x00080000),
   1481
   1482	/*
   1483	 * Right to use the object for synchronization.  Enables a process to
   1484	 * wait until the object is in the signalled state.  Some object types
   1485	 * do not support this access right.
   1486	 */
   1487	SYNCHRONIZE			= cpu_to_le32(0x00100000),
   1488
   1489	/*
   1490	 * The following STANDARD_RIGHTS_* are combinations of the above for
   1491	 * convenience and are defined by the Win32 API.
   1492	 */
   1493
   1494	/* These are currently defined to READ_CONTROL. */
   1495	STANDARD_RIGHTS_READ		= cpu_to_le32(0x00020000),
   1496	STANDARD_RIGHTS_WRITE		= cpu_to_le32(0x00020000),
   1497	STANDARD_RIGHTS_EXECUTE		= cpu_to_le32(0x00020000),
   1498
   1499	/* Combines DELETE, READ_CONTROL, WRITE_DAC, and WRITE_OWNER access. */
   1500	STANDARD_RIGHTS_REQUIRED	= cpu_to_le32(0x000f0000),
   1501
   1502	/*
   1503	 * Combines DELETE, READ_CONTROL, WRITE_DAC, WRITE_OWNER, and
   1504	 * SYNCHRONIZE access.
   1505	 */
   1506	STANDARD_RIGHTS_ALL		= cpu_to_le32(0x001f0000),
   1507
   1508	/*
   1509	 * The access system ACL and maximum allowed access types (bits 24 to
   1510	 * 25, bits 26 to 27 are reserved).
   1511	 */
   1512	ACCESS_SYSTEM_SECURITY		= cpu_to_le32(0x01000000),
   1513	MAXIMUM_ALLOWED			= cpu_to_le32(0x02000000),
   1514
   1515	/*
   1516	 * The generic rights (bits 28 to 31).  These map onto the standard and
   1517	 * specific rights.
   1518	 */
   1519
   1520	/* Read, write, and execute access. */
   1521	GENERIC_ALL			= cpu_to_le32(0x10000000),
   1522
   1523	/* Execute access. */
   1524	GENERIC_EXECUTE			= cpu_to_le32(0x20000000),
   1525
   1526	/*
   1527	 * Write access.  For files, this maps onto:
   1528	 *	FILE_APPEND_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_DATA |
   1529	 *	FILE_WRITE_EA | STANDARD_RIGHTS_WRITE | SYNCHRONIZE
   1530	 * For directories, the mapping has the same numerical value.  See
   1531	 * above for the descriptions of the rights granted.
   1532	 */
   1533	GENERIC_WRITE			= cpu_to_le32(0x40000000),
   1534
   1535	/*
   1536	 * Read access.  For files, this maps onto:
   1537	 *	FILE_READ_ATTRIBUTES | FILE_READ_DATA | FILE_READ_EA |
   1538	 *	STANDARD_RIGHTS_READ | SYNCHRONIZE
   1539	 * For directories, the mapping has the same numberical value.  See
   1540	 * above for the descriptions of the rights granted.
   1541	 */
   1542	GENERIC_READ			= cpu_to_le32(0x80000000),
   1543};
   1544
   1545typedef le32 ACCESS_MASK;
   1546
   1547/*
   1548 * The generic mapping array. Used to denote the mapping of each generic
   1549 * access right to a specific access mask.
   1550 *
   1551 * FIXME: What exactly is this and what is it for? (AIA)
   1552 */
   1553typedef struct {
   1554	ACCESS_MASK generic_read;
   1555	ACCESS_MASK generic_write;
   1556	ACCESS_MASK generic_execute;
   1557	ACCESS_MASK generic_all;
   1558} __attribute__ ((__packed__)) GENERIC_MAPPING;
   1559
   1560/*
   1561 * The predefined ACE type structures are as defined below.
   1562 */
   1563
   1564/*
   1565 * ACCESS_ALLOWED_ACE, ACCESS_DENIED_ACE, SYSTEM_AUDIT_ACE, SYSTEM_ALARM_ACE
   1566 */
   1567typedef struct {
   1568/*  0	ACE_HEADER; -- Unfolded here as gcc doesn't like unnamed structs. */
   1569	ACE_TYPES type;		/* Type of the ACE. */
   1570	ACE_FLAGS flags;	/* Flags describing the ACE. */
   1571	le16 size;		/* Size in bytes of the ACE. */
   1572/*  4*/	ACCESS_MASK mask;	/* Access mask associated with the ACE. */
   1573
   1574/*  8*/	SID sid;		/* The SID associated with the ACE. */
   1575} __attribute__ ((__packed__)) ACCESS_ALLOWED_ACE, ACCESS_DENIED_ACE,
   1576			       SYSTEM_AUDIT_ACE, SYSTEM_ALARM_ACE;
   1577
   1578/*
   1579 * The object ACE flags (32-bit).
   1580 */
   1581enum {
   1582	ACE_OBJECT_TYPE_PRESENT			= cpu_to_le32(1),
   1583	ACE_INHERITED_OBJECT_TYPE_PRESENT	= cpu_to_le32(2),
   1584};
   1585
   1586typedef le32 OBJECT_ACE_FLAGS;
   1587
   1588typedef struct {
   1589/*  0	ACE_HEADER; -- Unfolded here as gcc doesn't like unnamed structs. */
   1590	ACE_TYPES type;		/* Type of the ACE. */
   1591	ACE_FLAGS flags;	/* Flags describing the ACE. */
   1592	le16 size;		/* Size in bytes of the ACE. */
   1593/*  4*/	ACCESS_MASK mask;	/* Access mask associated with the ACE. */
   1594
   1595/*  8*/	OBJECT_ACE_FLAGS object_flags;	/* Flags describing the object ACE. */
   1596/* 12*/	GUID object_type;
   1597/* 28*/	GUID inherited_object_type;
   1598
   1599/* 44*/	SID sid;		/* The SID associated with the ACE. */
   1600} __attribute__ ((__packed__)) ACCESS_ALLOWED_OBJECT_ACE,
   1601			       ACCESS_DENIED_OBJECT_ACE,
   1602			       SYSTEM_AUDIT_OBJECT_ACE,
   1603			       SYSTEM_ALARM_OBJECT_ACE;
   1604
   1605/*
   1606 * An ACL is an access-control list (ACL).
   1607 * An ACL starts with an ACL header structure, which specifies the size of
   1608 * the ACL and the number of ACEs it contains. The ACL header is followed by
   1609 * zero or more access control entries (ACEs). The ACL as well as each ACE
   1610 * are aligned on 4-byte boundaries.
   1611 */
   1612typedef struct {
   1613	u8 revision;	/* Revision of this ACL. */
   1614	u8 alignment1;
   1615	le16 size;	/* Allocated space in bytes for ACL. Includes this
   1616			   header, the ACEs and the remaining free space. */
   1617	le16 ace_count;	/* Number of ACEs in the ACL. */
   1618	le16 alignment2;
   1619/* sizeof() = 8 bytes */
   1620} __attribute__ ((__packed__)) ACL;
   1621
   1622/*
   1623 * Current constants for ACLs.
   1624 */
   1625typedef enum {
   1626	/* Current revision. */
   1627	ACL_REVISION		= 2,
   1628	ACL_REVISION_DS		= 4,
   1629
   1630	/* History of revisions. */
   1631	ACL_REVISION1		= 1,
   1632	MIN_ACL_REVISION	= 2,
   1633	ACL_REVISION2		= 2,
   1634	ACL_REVISION3		= 3,
   1635	ACL_REVISION4		= 4,
   1636	MAX_ACL_REVISION	= 4,
   1637} ACL_CONSTANTS;
   1638
   1639/*
   1640 * The security descriptor control flags (16-bit).
   1641 *
   1642 * SE_OWNER_DEFAULTED - This boolean flag, when set, indicates that the SID
   1643 *	pointed to by the Owner field was provided by a defaulting mechanism
   1644 *	rather than explicitly provided by the original provider of the
   1645 *	security descriptor.  This may affect the treatment of the SID with
   1646 *	respect to inheritance of an owner.
   1647 *
   1648 * SE_GROUP_DEFAULTED - This boolean flag, when set, indicates that the SID in
   1649 *	the Group field was provided by a defaulting mechanism rather than
   1650 *	explicitly provided by the original provider of the security
   1651 *	descriptor.  This may affect the treatment of the SID with respect to
   1652 *	inheritance of a primary group.
   1653 *
   1654 * SE_DACL_PRESENT - This boolean flag, when set, indicates that the security
   1655 *	descriptor contains a discretionary ACL.  If this flag is set and the
   1656 *	Dacl field of the SECURITY_DESCRIPTOR is null, then a null ACL is
   1657 *	explicitly being specified.
   1658 *
   1659 * SE_DACL_DEFAULTED - This boolean flag, when set, indicates that the ACL
   1660 *	pointed to by the Dacl field was provided by a defaulting mechanism
   1661 *	rather than explicitly provided by the original provider of the
   1662 *	security descriptor.  This may affect the treatment of the ACL with
   1663 *	respect to inheritance of an ACL.  This flag is ignored if the
   1664 *	DaclPresent flag is not set.
   1665 *
   1666 * SE_SACL_PRESENT - This boolean flag, when set,  indicates that the security
   1667 *	descriptor contains a system ACL pointed to by the Sacl field.  If this
   1668 *	flag is set and the Sacl field of the SECURITY_DESCRIPTOR is null, then
   1669 *	an empty (but present) ACL is being specified.
   1670 *
   1671 * SE_SACL_DEFAULTED - This boolean flag, when set, indicates that the ACL
   1672 *	pointed to by the Sacl field was provided by a defaulting mechanism
   1673 *	rather than explicitly provided by the original provider of the
   1674 *	security descriptor.  This may affect the treatment of the ACL with
   1675 *	respect to inheritance of an ACL.  This flag is ignored if the
   1676 *	SaclPresent flag is not set.
   1677 *
   1678 * SE_SELF_RELATIVE - This boolean flag, when set, indicates that the security
   1679 *	descriptor is in self-relative form.  In this form, all fields of the
   1680 *	security descriptor are contiguous in memory and all pointer fields are
   1681 *	expressed as offsets from the beginning of the security descriptor.
   1682 */
   1683enum {
   1684	SE_OWNER_DEFAULTED		= cpu_to_le16(0x0001),
   1685	SE_GROUP_DEFAULTED		= cpu_to_le16(0x0002),
   1686	SE_DACL_PRESENT			= cpu_to_le16(0x0004),
   1687	SE_DACL_DEFAULTED		= cpu_to_le16(0x0008),
   1688
   1689	SE_SACL_PRESENT			= cpu_to_le16(0x0010),
   1690	SE_SACL_DEFAULTED		= cpu_to_le16(0x0020),
   1691
   1692	SE_DACL_AUTO_INHERIT_REQ	= cpu_to_le16(0x0100),
   1693	SE_SACL_AUTO_INHERIT_REQ	= cpu_to_le16(0x0200),
   1694	SE_DACL_AUTO_INHERITED		= cpu_to_le16(0x0400),
   1695	SE_SACL_AUTO_INHERITED		= cpu_to_le16(0x0800),
   1696
   1697	SE_DACL_PROTECTED		= cpu_to_le16(0x1000),
   1698	SE_SACL_PROTECTED		= cpu_to_le16(0x2000),
   1699	SE_RM_CONTROL_VALID		= cpu_to_le16(0x4000),
   1700	SE_SELF_RELATIVE		= cpu_to_le16(0x8000)
   1701} __attribute__ ((__packed__));
   1702
   1703typedef le16 SECURITY_DESCRIPTOR_CONTROL;
   1704
   1705/*
   1706 * Self-relative security descriptor. Contains the owner and group SIDs as well
   1707 * as the sacl and dacl ACLs inside the security descriptor itself.
   1708 */
   1709typedef struct {
   1710	u8 revision;	/* Revision level of the security descriptor. */
   1711	u8 alignment;
   1712	SECURITY_DESCRIPTOR_CONTROL control; /* Flags qualifying the type of
   1713			   the descriptor as well as the following fields. */
   1714	le32 owner;	/* Byte offset to a SID representing an object's
   1715			   owner. If this is NULL, no owner SID is present in
   1716			   the descriptor. */
   1717	le32 group;	/* Byte offset to a SID representing an object's
   1718			   primary group. If this is NULL, no primary group
   1719			   SID is present in the descriptor. */
   1720	le32 sacl;	/* Byte offset to a system ACL. Only valid, if
   1721			   SE_SACL_PRESENT is set in the control field. If
   1722			   SE_SACL_PRESENT is set but sacl is NULL, a NULL ACL
   1723			   is specified. */
   1724	le32 dacl;	/* Byte offset to a discretionary ACL. Only valid, if
   1725			   SE_DACL_PRESENT is set in the control field. If
   1726			   SE_DACL_PRESENT is set but dacl is NULL, a NULL ACL
   1727			   (unconditionally granting access) is specified. */
   1728/* sizeof() = 0x14 bytes */
   1729} __attribute__ ((__packed__)) SECURITY_DESCRIPTOR_RELATIVE;
   1730
   1731/*
   1732 * Absolute security descriptor. Does not contain the owner and group SIDs, nor
   1733 * the sacl and dacl ACLs inside the security descriptor. Instead, it contains
   1734 * pointers to these structures in memory. Obviously, absolute security
   1735 * descriptors are only useful for in memory representations of security
   1736 * descriptors. On disk, a self-relative security descriptor is used.
   1737 */
   1738typedef struct {
   1739	u8 revision;	/* Revision level of the security descriptor. */
   1740	u8 alignment;
   1741	SECURITY_DESCRIPTOR_CONTROL control;	/* Flags qualifying the type of
   1742			   the descriptor as well as the following fields. */
   1743	SID *owner;	/* Points to a SID representing an object's owner. If
   1744			   this is NULL, no owner SID is present in the
   1745			   descriptor. */
   1746	SID *group;	/* Points to a SID representing an object's primary
   1747			   group. If this is NULL, no primary group SID is
   1748			   present in the descriptor. */
   1749	ACL *sacl;	/* Points to a system ACL. Only valid, if
   1750			   SE_SACL_PRESENT is set in the control field. If
   1751			   SE_SACL_PRESENT is set but sacl is NULL, a NULL ACL
   1752			   is specified. */
   1753	ACL *dacl;	/* Points to a discretionary ACL. Only valid, if
   1754			   SE_DACL_PRESENT is set in the control field. If
   1755			   SE_DACL_PRESENT is set but dacl is NULL, a NULL ACL
   1756			   (unconditionally granting access) is specified. */
   1757} __attribute__ ((__packed__)) SECURITY_DESCRIPTOR;
   1758
   1759/*
   1760 * Current constants for security descriptors.
   1761 */
   1762typedef enum {
   1763	/* Current revision. */
   1764	SECURITY_DESCRIPTOR_REVISION	= 1,
   1765	SECURITY_DESCRIPTOR_REVISION1	= 1,
   1766
   1767	/* The sizes of both the absolute and relative security descriptors is
   1768	   the same as pointers, at least on ia32 architecture are 32-bit. */
   1769	SECURITY_DESCRIPTOR_MIN_LENGTH	= sizeof(SECURITY_DESCRIPTOR),
   1770} SECURITY_DESCRIPTOR_CONSTANTS;
   1771
   1772/*
   1773 * Attribute: Security descriptor (0x50). A standard self-relative security
   1774 * descriptor.
   1775 *
   1776 * NOTE: Can be resident or non-resident.
   1777 * NOTE: Not used in NTFS 3.0+, as security descriptors are stored centrally
   1778 * in FILE_Secure and the correct descriptor is found using the security_id
   1779 * from the standard information attribute.
   1780 */
   1781typedef SECURITY_DESCRIPTOR_RELATIVE SECURITY_DESCRIPTOR_ATTR;
   1782
   1783/*
   1784 * On NTFS 3.0+, all security descriptors are stored in FILE_Secure. Only one
   1785 * referenced instance of each unique security descriptor is stored.
   1786 *
   1787 * FILE_Secure contains no unnamed data attribute, i.e. it has zero length. It
   1788 * does, however, contain two indexes ($SDH and $SII) as well as a named data
   1789 * stream ($SDS).
   1790 *
   1791 * Every unique security descriptor is assigned a unique security identifier
   1792 * (security_id, not to be confused with a SID). The security_id is unique for
   1793 * the NTFS volume and is used as an index into the $SII index, which maps
   1794 * security_ids to the security descriptor's storage location within the $SDS
   1795 * data attribute. The $SII index is sorted by ascending security_id.
   1796 *
   1797 * A simple hash is computed from each security descriptor. This hash is used
   1798 * as an index into the $SDH index, which maps security descriptor hashes to
   1799 * the security descriptor's storage location within the $SDS data attribute.
   1800 * The $SDH index is sorted by security descriptor hash and is stored in a B+
   1801 * tree. When searching $SDH (with the intent of determining whether or not a
   1802 * new security descriptor is already present in the $SDS data stream), if a
   1803 * matching hash is found, but the security descriptors do not match, the
   1804 * search in the $SDH index is continued, searching for a next matching hash.
   1805 *
   1806 * When a precise match is found, the security_id coresponding to the security
   1807 * descriptor in the $SDS attribute is read from the found $SDH index entry and
   1808 * is stored in the $STANDARD_INFORMATION attribute of the file/directory to
   1809 * which the security descriptor is being applied. The $STANDARD_INFORMATION
   1810 * attribute is present in all base mft records (i.e. in all files and
   1811 * directories).
   1812 *
   1813 * If a match is not found, the security descriptor is assigned a new unique
   1814 * security_id and is added to the $SDS data attribute. Then, entries
   1815 * referencing the this security descriptor in the $SDS data attribute are
   1816 * added to the $SDH and $SII indexes.
   1817 *
   1818 * Note: Entries are never deleted from FILE_Secure, even if nothing
   1819 * references an entry any more.
   1820 */
   1821
   1822/*
   1823 * This header precedes each security descriptor in the $SDS data stream.
   1824 * This is also the index entry data part of both the $SII and $SDH indexes.
   1825 */
   1826typedef struct {
   1827	le32 hash;	  /* Hash of the security descriptor. */
   1828	le32 security_id; /* The security_id assigned to the descriptor. */
   1829	le64 offset;	  /* Byte offset of this entry in the $SDS stream. */
   1830	le32 length;	  /* Size in bytes of this entry in $SDS stream. */
   1831} __attribute__ ((__packed__)) SECURITY_DESCRIPTOR_HEADER;
   1832
   1833/*
   1834 * The $SDS data stream contains the security descriptors, aligned on 16-byte
   1835 * boundaries, sorted by security_id in a B+ tree. Security descriptors cannot
   1836 * cross 256kib boundaries (this restriction is imposed by the Windows cache
   1837 * manager). Each security descriptor is contained in a SDS_ENTRY structure.
   1838 * Also, each security descriptor is stored twice in the $SDS stream with a
   1839 * fixed offset of 0x40000 bytes (256kib, the Windows cache manager's max size)
   1840 * between them; i.e. if a SDS_ENTRY specifies an offset of 0x51d0, then the
   1841 * first copy of the security descriptor will be at offset 0x51d0 in the
   1842 * $SDS data stream and the second copy will be at offset 0x451d0.
   1843 */
   1844typedef struct {
   1845/*Ofs*/
   1846/*  0	SECURITY_DESCRIPTOR_HEADER; -- Unfolded here as gcc doesn't like
   1847				       unnamed structs. */
   1848	le32 hash;	  /* Hash of the security descriptor. */
   1849	le32 security_id; /* The security_id assigned to the descriptor. */
   1850	le64 offset;	  /* Byte offset of this entry in the $SDS stream. */
   1851	le32 length;	  /* Size in bytes of this entry in $SDS stream. */
   1852/* 20*/	SECURITY_DESCRIPTOR_RELATIVE sid; /* The self-relative security
   1853					     descriptor. */
   1854} __attribute__ ((__packed__)) SDS_ENTRY;
   1855
   1856/*
   1857 * The index entry key used in the $SII index. The collation type is
   1858 * COLLATION_NTOFS_ULONG.
   1859 */
   1860typedef struct {
   1861	le32 security_id; /* The security_id assigned to the descriptor. */
   1862} __attribute__ ((__packed__)) SII_INDEX_KEY;
   1863
   1864/*
   1865 * The index entry key used in the $SDH index. The keys are sorted first by
   1866 * hash and then by security_id. The collation rule is
   1867 * COLLATION_NTOFS_SECURITY_HASH.
   1868 */
   1869typedef struct {
   1870	le32 hash;	  /* Hash of the security descriptor. */
   1871	le32 security_id; /* The security_id assigned to the descriptor. */
   1872} __attribute__ ((__packed__)) SDH_INDEX_KEY;
   1873
   1874/*
   1875 * Attribute: Volume name (0x60).
   1876 *
   1877 * NOTE: Always resident.
   1878 * NOTE: Present only in FILE_Volume.
   1879 */
   1880typedef struct {
   1881	ntfschar name[0];	/* The name of the volume in Unicode. */
   1882} __attribute__ ((__packed__)) VOLUME_NAME;
   1883
   1884/*
   1885 * Possible flags for the volume (16-bit).
   1886 */
   1887enum {
   1888	VOLUME_IS_DIRTY			= cpu_to_le16(0x0001),
   1889	VOLUME_RESIZE_LOG_FILE		= cpu_to_le16(0x0002),
   1890	VOLUME_UPGRADE_ON_MOUNT		= cpu_to_le16(0x0004),
   1891	VOLUME_MOUNTED_ON_NT4		= cpu_to_le16(0x0008),
   1892
   1893	VOLUME_DELETE_USN_UNDERWAY	= cpu_to_le16(0x0010),
   1894	VOLUME_REPAIR_OBJECT_ID		= cpu_to_le16(0x0020),
   1895
   1896	VOLUME_CHKDSK_UNDERWAY		= cpu_to_le16(0x4000),
   1897	VOLUME_MODIFIED_BY_CHKDSK	= cpu_to_le16(0x8000),
   1898
   1899	VOLUME_FLAGS_MASK		= cpu_to_le16(0xc03f),
   1900
   1901	/* To make our life easier when checking if we must mount read-only. */
   1902	VOLUME_MUST_MOUNT_RO_MASK	= cpu_to_le16(0xc027),
   1903} __attribute__ ((__packed__));
   1904
   1905typedef le16 VOLUME_FLAGS;
   1906
   1907/*
   1908 * Attribute: Volume information (0x70).
   1909 *
   1910 * NOTE: Always resident.
   1911 * NOTE: Present only in FILE_Volume.
   1912 * NOTE: Windows 2000 uses NTFS 3.0 while Windows NT4 service pack 6a uses
   1913 *	 NTFS 1.2. I haven't personally seen other values yet.
   1914 */
   1915typedef struct {
   1916	le64 reserved;		/* Not used (yet?). */
   1917	u8 major_ver;		/* Major version of the ntfs format. */
   1918	u8 minor_ver;		/* Minor version of the ntfs format. */
   1919	VOLUME_FLAGS flags;	/* Bit array of VOLUME_* flags. */
   1920} __attribute__ ((__packed__)) VOLUME_INFORMATION;
   1921
   1922/*
   1923 * Attribute: Data attribute (0x80).
   1924 *
   1925 * NOTE: Can be resident or non-resident.
   1926 *
   1927 * Data contents of a file (i.e. the unnamed stream) or of a named stream.
   1928 */
   1929typedef struct {
   1930	u8 data[0];		/* The file's data contents. */
   1931} __attribute__ ((__packed__)) DATA_ATTR;
   1932
   1933/*
   1934 * Index header flags (8-bit).
   1935 */
   1936enum {
   1937	/*
   1938	 * When index header is in an index root attribute:
   1939	 */
   1940	SMALL_INDEX = 0, /* The index is small enough to fit inside the index
   1941			    root attribute and there is no index allocation
   1942			    attribute present. */
   1943	LARGE_INDEX = 1, /* The index is too large to fit in the index root
   1944			    attribute and/or an index allocation attribute is
   1945			    present. */
   1946	/*
   1947	 * When index header is in an index block, i.e. is part of index
   1948	 * allocation attribute:
   1949	 */
   1950	LEAF_NODE  = 0, /* This is a leaf node, i.e. there are no more nodes
   1951			   branching off it. */
   1952	INDEX_NODE = 1, /* This node indexes other nodes, i.e. it is not a leaf
   1953			   node. */
   1954	NODE_MASK  = 1, /* Mask for accessing the *_NODE bits. */
   1955} __attribute__ ((__packed__));
   1956
   1957typedef u8 INDEX_HEADER_FLAGS;
   1958
   1959/*
   1960 * This is the header for indexes, describing the INDEX_ENTRY records, which
   1961 * follow the INDEX_HEADER. Together the index header and the index entries
   1962 * make up a complete index.
   1963 *
   1964 * IMPORTANT NOTE: The offset, length and size structure members are counted
   1965 * relative to the start of the index header structure and not relative to the
   1966 * start of the index root or index allocation structures themselves.
   1967 */
   1968typedef struct {
   1969	le32 entries_offset;		/* Byte offset to first INDEX_ENTRY
   1970					   aligned to 8-byte boundary. */
   1971	le32 index_length;		/* Data size of the index in bytes,
   1972					   i.e. bytes used from allocated
   1973					   size, aligned to 8-byte boundary. */
   1974	le32 allocated_size;		/* Byte size of this index (block),
   1975					   multiple of 8 bytes. */
   1976	/* NOTE: For the index root attribute, the above two numbers are always
   1977	   equal, as the attribute is resident and it is resized as needed. In
   1978	   the case of the index allocation attribute the attribute is not
   1979	   resident and hence the allocated_size is a fixed value and must
   1980	   equal the index_block_size specified by the INDEX_ROOT attribute
   1981	   corresponding to the INDEX_ALLOCATION attribute this INDEX_BLOCK
   1982	   belongs to. */
   1983	INDEX_HEADER_FLAGS flags;	/* Bit field of INDEX_HEADER_FLAGS. */
   1984	u8 reserved[3];			/* Reserved/align to 8-byte boundary. */
   1985} __attribute__ ((__packed__)) INDEX_HEADER;
   1986
   1987/*
   1988 * Attribute: Index root (0x90).
   1989 *
   1990 * NOTE: Always resident.
   1991 *
   1992 * This is followed by a sequence of index entries (INDEX_ENTRY structures)
   1993 * as described by the index header.
   1994 *
   1995 * When a directory is small enough to fit inside the index root then this
   1996 * is the only attribute describing the directory. When the directory is too
   1997 * large to fit in the index root, on the other hand, two additional attributes
   1998 * are present: an index allocation attribute, containing sub-nodes of the B+
   1999 * directory tree (see below), and a bitmap attribute, describing which virtual
   2000 * cluster numbers (vcns) in the index allocation attribute are in use by an
   2001 * index block.
   2002 *
   2003 * NOTE: The root directory (FILE_root) contains an entry for itself. Other
   2004 * directories do not contain entries for themselves, though.
   2005 */
   2006typedef struct {
   2007	ATTR_TYPE type;			/* Type of the indexed attribute. Is
   2008					   $FILE_NAME for directories, zero
   2009					   for view indexes. No other values
   2010					   allowed. */
   2011	COLLATION_RULE collation_rule;	/* Collation rule used to sort the
   2012					   index entries. If type is $FILE_NAME,
   2013					   this must be COLLATION_FILE_NAME. */
   2014	le32 index_block_size;		/* Size of each index block in bytes (in
   2015					   the index allocation attribute). */
   2016	u8 clusters_per_index_block;	/* Cluster size of each index block (in
   2017					   the index allocation attribute), when
   2018					   an index block is >= than a cluster,
   2019					   otherwise this will be the log of
   2020					   the size (like how the encoding of
   2021					   the mft record size and the index
   2022					   record size found in the boot sector
   2023					   work). Has to be a power of 2. */
   2024	u8 reserved[3];			/* Reserved/align to 8-byte boundary. */
   2025	INDEX_HEADER index;		/* Index header describing the
   2026					   following index entries. */
   2027} __attribute__ ((__packed__)) INDEX_ROOT;
   2028
   2029/*
   2030 * Attribute: Index allocation (0xa0).
   2031 *
   2032 * NOTE: Always non-resident (doesn't make sense to be resident anyway!).
   2033 *
   2034 * This is an array of index blocks. Each index block starts with an
   2035 * INDEX_BLOCK structure containing an index header, followed by a sequence of
   2036 * index entries (INDEX_ENTRY structures), as described by the INDEX_HEADER.
   2037 */
   2038typedef struct {
   2039/*  0	NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
   2040	NTFS_RECORD_TYPE magic;	/* Magic is "INDX". */
   2041	le16 usa_ofs;		/* See NTFS_RECORD definition. */
   2042	le16 usa_count;		/* See NTFS_RECORD definition. */
   2043
   2044/*  8*/	sle64 lsn;		/* $LogFile sequence number of the last
   2045				   modification of this index block. */
   2046/* 16*/	leVCN index_block_vcn;	/* Virtual cluster number of the index block.
   2047				   If the cluster_size on the volume is <= the
   2048				   index_block_size of the directory,
   2049				   index_block_vcn counts in units of clusters,
   2050				   and in units of sectors otherwise. */
   2051/* 24*/	INDEX_HEADER index;	/* Describes the following index entries. */
   2052/* sizeof()= 40 (0x28) bytes */
   2053/*
   2054 * When creating the index block, we place the update sequence array at this
   2055 * offset, i.e. before we start with the index entries. This also makes sense,
   2056 * otherwise we could run into problems with the update sequence array
   2057 * containing in itself the last two bytes of a sector which would mean that
   2058 * multi sector transfer protection wouldn't work. As you can't protect data
   2059 * by overwriting it since you then can't get it back...
   2060 * When reading use the data from the ntfs record header.
   2061 */
   2062} __attribute__ ((__packed__)) INDEX_BLOCK;
   2063
   2064typedef INDEX_BLOCK INDEX_ALLOCATION;
   2065
   2066/*
   2067 * The system file FILE_Extend/$Reparse contains an index named $R listing
   2068 * all reparse points on the volume. The index entry keys are as defined
   2069 * below. Note, that there is no index data associated with the index entries.
   2070 *
   2071 * The index entries are sorted by the index key file_id. The collation rule is
   2072 * COLLATION_NTOFS_ULONGS. FIXME: Verify whether the reparse_tag is not the
   2073 * primary key / is not a key at all. (AIA)
   2074 */
   2075typedef struct {
   2076	le32 reparse_tag;	/* Reparse point type (inc. flags). */
   2077	leMFT_REF file_id;	/* Mft record of the file containing the
   2078				   reparse point attribute. */
   2079} __attribute__ ((__packed__)) REPARSE_INDEX_KEY;
   2080
   2081/*
   2082 * Quota flags (32-bit).
   2083 *
   2084 * The user quota flags.  Names explain meaning.
   2085 */
   2086enum {
   2087	QUOTA_FLAG_DEFAULT_LIMITS	= cpu_to_le32(0x00000001),
   2088	QUOTA_FLAG_LIMIT_REACHED	= cpu_to_le32(0x00000002),
   2089	QUOTA_FLAG_ID_DELETED		= cpu_to_le32(0x00000004),
   2090
   2091	QUOTA_FLAG_USER_MASK		= cpu_to_le32(0x00000007),
   2092	/* This is a bit mask for the user quota flags. */
   2093
   2094	/*
   2095	 * These flags are only present in the quota defaults index entry, i.e.
   2096	 * in the entry where owner_id = QUOTA_DEFAULTS_ID.
   2097	 */
   2098	QUOTA_FLAG_TRACKING_ENABLED	= cpu_to_le32(0x00000010),
   2099	QUOTA_FLAG_ENFORCEMENT_ENABLED	= cpu_to_le32(0x00000020),
   2100	QUOTA_FLAG_TRACKING_REQUESTED	= cpu_to_le32(0x00000040),
   2101	QUOTA_FLAG_LOG_THRESHOLD	= cpu_to_le32(0x00000080),
   2102
   2103	QUOTA_FLAG_LOG_LIMIT		= cpu_to_le32(0x00000100),
   2104	QUOTA_FLAG_OUT_OF_DATE		= cpu_to_le32(0x00000200),
   2105	QUOTA_FLAG_CORRUPT		= cpu_to_le32(0x00000400),
   2106	QUOTA_FLAG_PENDING_DELETES	= cpu_to_le32(0x00000800),
   2107};
   2108
   2109typedef le32 QUOTA_FLAGS;
   2110
   2111/*
   2112 * The system file FILE_Extend/$Quota contains two indexes $O and $Q. Quotas
   2113 * are on a per volume and per user basis.
   2114 *
   2115 * The $Q index contains one entry for each existing user_id on the volume. The
   2116 * index key is the user_id of the user/group owning this quota control entry,
   2117 * i.e. the key is the owner_id. The user_id of the owner of a file, i.e. the
   2118 * owner_id, is found in the standard information attribute. The collation rule
   2119 * for $Q is COLLATION_NTOFS_ULONG.
   2120 *
   2121 * The $O index contains one entry for each user/group who has been assigned
   2122 * a quota on that volume. The index key holds the SID of the user_id the
   2123 * entry belongs to, i.e. the owner_id. The collation rule for $O is
   2124 * COLLATION_NTOFS_SID.
   2125 *
   2126 * The $O index entry data is the user_id of the user corresponding to the SID.
   2127 * This user_id is used as an index into $Q to find the quota control entry
   2128 * associated with the SID.
   2129 *
   2130 * The $Q index entry data is the quota control entry and is defined below.
   2131 */
   2132typedef struct {
   2133	le32 version;		/* Currently equals 2. */
   2134	QUOTA_FLAGS flags;	/* Flags describing this quota entry. */
   2135	le64 bytes_used;	/* How many bytes of the quota are in use. */
   2136	sle64 change_time;	/* Last time this quota entry was changed. */
   2137	sle64 threshold;	/* Soft quota (-1 if not limited). */
   2138	sle64 limit;		/* Hard quota (-1 if not limited). */
   2139	sle64 exceeded_time;	/* How long the soft quota has been exceeded. */
   2140	SID sid;		/* The SID of the user/object associated with
   2141				   this quota entry.  Equals zero for the quota
   2142				   defaults entry (and in fact on a WinXP
   2143				   volume, it is not present at all). */
   2144} __attribute__ ((__packed__)) QUOTA_CONTROL_ENTRY;
   2145
   2146/*
   2147 * Predefined owner_id values (32-bit).
   2148 */
   2149enum {
   2150	QUOTA_INVALID_ID	= cpu_to_le32(0x00000000),
   2151	QUOTA_DEFAULTS_ID	= cpu_to_le32(0x00000001),
   2152	QUOTA_FIRST_USER_ID	= cpu_to_le32(0x00000100),
   2153};
   2154
   2155/*
   2156 * Current constants for quota control entries.
   2157 */
   2158typedef enum {
   2159	/* Current version. */
   2160	QUOTA_VERSION	= 2,
   2161} QUOTA_CONTROL_ENTRY_CONSTANTS;
   2162
   2163/*
   2164 * Index entry flags (16-bit).
   2165 */
   2166enum {
   2167	INDEX_ENTRY_NODE = cpu_to_le16(1), /* This entry contains a
   2168			sub-node, i.e. a reference to an index block in form of
   2169			a virtual cluster number (see below). */
   2170	INDEX_ENTRY_END  = cpu_to_le16(2), /* This signifies the last
   2171			entry in an index block.  The index entry does not
   2172			represent a file but it can point to a sub-node. */
   2173
   2174	INDEX_ENTRY_SPACE_FILLER = cpu_to_le16(0xffff), /* gcc: Force
   2175			enum bit width to 16-bit. */
   2176} __attribute__ ((__packed__));
   2177
   2178typedef le16 INDEX_ENTRY_FLAGS;
   2179
   2180/*
   2181 * This the index entry header (see below).
   2182 */
   2183typedef struct {
   2184/*  0*/	union {
   2185		struct { /* Only valid when INDEX_ENTRY_END is not set. */
   2186			leMFT_REF indexed_file;	/* The mft reference of the file
   2187						   described by this index
   2188						   entry. Used for directory
   2189						   indexes. */
   2190		} __attribute__ ((__packed__)) dir;
   2191		struct { /* Used for views/indexes to find the entry's data. */
   2192			le16 data_offset;	/* Data byte offset from this
   2193						   INDEX_ENTRY. Follows the
   2194						   index key. */
   2195			le16 data_length;	/* Data length in bytes. */
   2196			le32 reservedV;		/* Reserved (zero). */
   2197		} __attribute__ ((__packed__)) vi;
   2198	} __attribute__ ((__packed__)) data;
   2199/*  8*/	le16 length;		 /* Byte size of this index entry, multiple of
   2200				    8-bytes. */
   2201/* 10*/	le16 key_length;	 /* Byte size of the key value, which is in the
   2202				    index entry. It follows field reserved. Not
   2203				    multiple of 8-bytes. */
   2204/* 12*/	INDEX_ENTRY_FLAGS flags; /* Bit field of INDEX_ENTRY_* flags. */
   2205/* 14*/	le16 reserved;		 /* Reserved/align to 8-byte boundary. */
   2206/* sizeof() = 16 bytes */
   2207} __attribute__ ((__packed__)) INDEX_ENTRY_HEADER;
   2208
   2209/*
   2210 * This is an index entry. A sequence of such entries follows each INDEX_HEADER
   2211 * structure. Together they make up a complete index. The index follows either
   2212 * an index root attribute or an index allocation attribute.
   2213 *
   2214 * NOTE: Before NTFS 3.0 only filename attributes were indexed.
   2215 */
   2216typedef struct {
   2217/*Ofs*/
   2218/*  0	INDEX_ENTRY_HEADER; -- Unfolded here as gcc dislikes unnamed structs. */
   2219	union {
   2220		struct { /* Only valid when INDEX_ENTRY_END is not set. */
   2221			leMFT_REF indexed_file;	/* The mft reference of the file
   2222						   described by this index
   2223						   entry. Used for directory
   2224						   indexes. */
   2225		} __attribute__ ((__packed__)) dir;
   2226		struct { /* Used for views/indexes to find the entry's data. */
   2227			le16 data_offset;	/* Data byte offset from this
   2228						   INDEX_ENTRY. Follows the
   2229						   index key. */
   2230			le16 data_length;	/* Data length in bytes. */
   2231			le32 reservedV;		/* Reserved (zero). */
   2232		} __attribute__ ((__packed__)) vi;
   2233	} __attribute__ ((__packed__)) data;
   2234	le16 length;		 /* Byte size of this index entry, multiple of
   2235				    8-bytes. */
   2236	le16 key_length;	 /* Byte size of the key value, which is in the
   2237				    index entry. It follows field reserved. Not
   2238				    multiple of 8-bytes. */
   2239	INDEX_ENTRY_FLAGS flags; /* Bit field of INDEX_ENTRY_* flags. */
   2240	le16 reserved;		 /* Reserved/align to 8-byte boundary. */
   2241
   2242/* 16*/	union {		/* The key of the indexed attribute. NOTE: Only present
   2243			   if INDEX_ENTRY_END bit in flags is not set. NOTE: On
   2244			   NTFS versions before 3.0 the only valid key is the
   2245			   FILE_NAME_ATTR. On NTFS 3.0+ the following
   2246			   additional index keys are defined: */
   2247		FILE_NAME_ATTR file_name;/* $I30 index in directories. */
   2248		SII_INDEX_KEY sii;	/* $SII index in $Secure. */
   2249		SDH_INDEX_KEY sdh;	/* $SDH index in $Secure. */
   2250		GUID object_id;		/* $O index in FILE_Extend/$ObjId: The
   2251					   object_id of the mft record found in
   2252					   the data part of the index. */
   2253		REPARSE_INDEX_KEY reparse;	/* $R index in
   2254						   FILE_Extend/$Reparse. */
   2255		SID sid;		/* $O index in FILE_Extend/$Quota:
   2256					   SID of the owner of the user_id. */
   2257		le32 owner_id;		/* $Q index in FILE_Extend/$Quota:
   2258					   user_id of the owner of the quota
   2259					   control entry in the data part of
   2260					   the index. */
   2261	} __attribute__ ((__packed__)) key;
   2262	/* The (optional) index data is inserted here when creating. */
   2263	// leVCN vcn;	/* If INDEX_ENTRY_NODE bit in flags is set, the last
   2264	//		   eight bytes of this index entry contain the virtual
   2265	//		   cluster number of the index block that holds the
   2266	//		   entries immediately preceding the current entry (the
   2267	//		   vcn references the corresponding cluster in the data
   2268	//		   of the non-resident index allocation attribute). If
   2269	//		   the key_length is zero, then the vcn immediately
   2270	//		   follows the INDEX_ENTRY_HEADER. Regardless of
   2271	//		   key_length, the address of the 8-byte boundary
   2272	//		   aligned vcn of INDEX_ENTRY{_HEADER} *ie is given by
   2273	//		   (char*)ie + le16_to_cpu(ie*)->length) - sizeof(VCN),
   2274	//		   where sizeof(VCN) can be hardcoded as 8 if wanted. */
   2275} __attribute__ ((__packed__)) INDEX_ENTRY;
   2276
   2277/*
   2278 * Attribute: Bitmap (0xb0).
   2279 *
   2280 * Contains an array of bits (aka a bitfield).
   2281 *
   2282 * When used in conjunction with the index allocation attribute, each bit
   2283 * corresponds to one index block within the index allocation attribute. Thus
   2284 * the number of bits in the bitmap * index block size / cluster size is the
   2285 * number of clusters in the index allocation attribute.
   2286 */
   2287typedef struct {
   2288	u8 bitmap[0];			/* Array of bits. */
   2289} __attribute__ ((__packed__)) BITMAP_ATTR;
   2290
   2291/*
   2292 * The reparse point tag defines the type of the reparse point. It also
   2293 * includes several flags, which further describe the reparse point.
   2294 *
   2295 * The reparse point tag is an unsigned 32-bit value divided in three parts:
   2296 *
   2297 * 1. The least significant 16 bits (i.e. bits 0 to 15) specifiy the type of
   2298 *    the reparse point.
   2299 * 2. The 13 bits after this (i.e. bits 16 to 28) are reserved for future use.
   2300 * 3. The most significant three bits are flags describing the reparse point.
   2301 *    They are defined as follows:
   2302 *	bit 29: Name surrogate bit. If set, the filename is an alias for
   2303 *		another object in the system.
   2304 *	bit 30: High-latency bit. If set, accessing the first byte of data will
   2305 *		be slow. (E.g. the data is stored on a tape drive.)
   2306 *	bit 31: Microsoft bit. If set, the tag is owned by Microsoft. User
   2307 *		defined tags have to use zero here.
   2308 *
   2309 * These are the predefined reparse point tags:
   2310 */
   2311enum {
   2312	IO_REPARSE_TAG_IS_ALIAS		= cpu_to_le32(0x20000000),
   2313	IO_REPARSE_TAG_IS_HIGH_LATENCY	= cpu_to_le32(0x40000000),
   2314	IO_REPARSE_TAG_IS_MICROSOFT	= cpu_to_le32(0x80000000),
   2315
   2316	IO_REPARSE_TAG_RESERVED_ZERO	= cpu_to_le32(0x00000000),
   2317	IO_REPARSE_TAG_RESERVED_ONE	= cpu_to_le32(0x00000001),
   2318	IO_REPARSE_TAG_RESERVED_RANGE	= cpu_to_le32(0x00000001),
   2319
   2320	IO_REPARSE_TAG_NSS		= cpu_to_le32(0x68000005),
   2321	IO_REPARSE_TAG_NSS_RECOVER	= cpu_to_le32(0x68000006),
   2322	IO_REPARSE_TAG_SIS		= cpu_to_le32(0x68000007),
   2323	IO_REPARSE_TAG_DFS		= cpu_to_le32(0x68000008),
   2324
   2325	IO_REPARSE_TAG_MOUNT_POINT	= cpu_to_le32(0x88000003),
   2326
   2327	IO_REPARSE_TAG_HSM		= cpu_to_le32(0xa8000004),
   2328
   2329	IO_REPARSE_TAG_SYMBOLIC_LINK	= cpu_to_le32(0xe8000000),
   2330
   2331	IO_REPARSE_TAG_VALID_VALUES	= cpu_to_le32(0xe000ffff),
   2332};
   2333
   2334/*
   2335 * Attribute: Reparse point (0xc0).
   2336 *
   2337 * NOTE: Can be resident or non-resident.
   2338 */
   2339typedef struct {
   2340	le32 reparse_tag;		/* Reparse point type (inc. flags). */
   2341	le16 reparse_data_length;	/* Byte size of reparse data. */
   2342	le16 reserved;			/* Align to 8-byte boundary. */
   2343	u8 reparse_data[0];		/* Meaning depends on reparse_tag. */
   2344} __attribute__ ((__packed__)) REPARSE_POINT;
   2345
   2346/*
   2347 * Attribute: Extended attribute (EA) information (0xd0).
   2348 *
   2349 * NOTE: Always resident. (Is this true???)
   2350 */
   2351typedef struct {
   2352	le16 ea_length;		/* Byte size of the packed extended
   2353				   attributes. */
   2354	le16 need_ea_count;	/* The number of extended attributes which have
   2355				   the NEED_EA bit set. */
   2356	le32 ea_query_length;	/* Byte size of the buffer required to query
   2357				   the extended attributes when calling
   2358				   ZwQueryEaFile() in Windows NT/2k. I.e. the
   2359				   byte size of the unpacked extended
   2360				   attributes. */
   2361} __attribute__ ((__packed__)) EA_INFORMATION;
   2362
   2363/*
   2364 * Extended attribute flags (8-bit).
   2365 */
   2366enum {
   2367	NEED_EA	= 0x80		/* If set the file to which the EA belongs
   2368				   cannot be interpreted without understanding
   2369				   the associates extended attributes. */
   2370} __attribute__ ((__packed__));
   2371
   2372typedef u8 EA_FLAGS;
   2373
   2374/*
   2375 * Attribute: Extended attribute (EA) (0xe0).
   2376 *
   2377 * NOTE: Can be resident or non-resident.
   2378 *
   2379 * Like the attribute list and the index buffer list, the EA attribute value is
   2380 * a sequence of EA_ATTR variable length records.
   2381 */
   2382typedef struct {
   2383	le32 next_entry_offset;	/* Offset to the next EA_ATTR. */
   2384	EA_FLAGS flags;		/* Flags describing the EA. */
   2385	u8 ea_name_length;	/* Length of the name of the EA in bytes
   2386				   excluding the '\0' byte terminator. */
   2387	le16 ea_value_length;	/* Byte size of the EA's value. */
   2388	u8 ea_name[0];		/* Name of the EA.  Note this is ASCII, not
   2389				   Unicode and it is zero terminated. */
   2390	u8 ea_value[0];		/* The value of the EA.  Immediately follows
   2391				   the name. */
   2392} __attribute__ ((__packed__)) EA_ATTR;
   2393
   2394/*
   2395 * Attribute: Property set (0xf0).
   2396 *
   2397 * Intended to support Native Structure Storage (NSS) - a feature removed from
   2398 * NTFS 3.0 during beta testing.
   2399 */
   2400typedef struct {
   2401	/* Irrelevant as feature unused. */
   2402} __attribute__ ((__packed__)) PROPERTY_SET;
   2403
   2404/*
   2405 * Attribute: Logged utility stream (0x100).
   2406 *
   2407 * NOTE: Can be resident or non-resident.
   2408 *
   2409 * Operations on this attribute are logged to the journal ($LogFile) like
   2410 * normal metadata changes.
   2411 *
   2412 * Used by the Encrypting File System (EFS). All encrypted files have this
   2413 * attribute with the name $EFS.
   2414 */
   2415typedef struct {
   2416	/* Can be anything the creator chooses. */
   2417	/* EFS uses it as follows: */
   2418	// FIXME: Type this info, verifying it along the way. (AIA)
   2419} __attribute__ ((__packed__)) LOGGED_UTILITY_STREAM, EFS_ATTR;
   2420
   2421#endif /* _LINUX_NTFS_LAYOUT_H */