/*
 * COPYRIGHT:		 See COPYRIGHT.TXT
 * PROJECT:          Ext2 File System for NT
 * FILE:             Ext2fs.h
 * PURPOSE:          Header file: ext2 structures
 * PROGRAMMER:       Matt Wu <mattwu@163.com>
 * HOMEPAGE:		 http://ext2.yeah.net
 * UPDATE HISTORY: 
 */

#ifndef _EXT2_HEADER_
#define _EXT2_HEADER_

/* INCLUDES *****************************************************************/

#include <ntdddisk.h>

/* DEBUG *****************************************************************/
#undef  DBG
#define DBG 0

/* STRUCTS & CONSTS******************************************************/

#define EXT2_RO

/* Ext2 releated ******************************************************/
#pragma pack(1)

#define SECTOR_SIZE (512)

typedef struct ext2_super_block {
	ULONG	s_inodes_count;		/* Inodes count */
	ULONG	s_blocks_count;		/* Blocks count */
	ULONG	s_r_blocks_count;	/* Reserved blocks count */
	ULONG	s_free_blocks_count;	/* Free blocks count */
	ULONG	s_free_inodes_count;	/* Free inodes count */
	ULONG	s_first_data_block;	/* First Data Block */
	ULONG	s_log_block_size;	/* Block size */
	LONG	s_log_frag_size;	/* Fragment size */
	ULONG	s_blocks_per_group;	/* # Blocks per group */
	ULONG	s_frags_per_group;	/* # Fragments per group */
	ULONG	s_inodes_per_group;	/* # Inodes per group */
	ULONG	s_mtime;		/* Mount time */
	ULONG	s_wtime;		/* Write time */
	USHORT	s_mnt_count;		/* Mount count */
	SHORT	s_max_mnt_count;	/* Maximal mount count */
	USHORT	s_magic;		/* Magic signature */
	USHORT	s_state;		/* File system state */
	USHORT	s_errors;		/* Behaviour when detecting errors */
	USHORT	s_minor_rev_level; 	/* minor revision level */
	ULONG	s_lastcheck;		/* time of last check */
	ULONG	s_checkinterval;	/* max. time between checks */
	ULONG	s_creator_os;		/* OS */
	ULONG	s_rev_level;		/* Revision level */
	USHORT	s_def_resuid;		/* Default uid for reserved blocks */
	USHORT	s_def_resgid;		/* Default gid for reserved blocks */
	/*
	 * These fields are for EXT2_DYNAMIC_REV superblocks only.
	 *
	 * Note: the difference between the compatible feature set and
	 * the incompatible feature set is that if there is a bit set
	 * in the incompatible feature set that the kernel doesn't
	 * know about, it should refuse to mount the filesystem.
	 * 
	 * e2fsck's requirements are more strict; if it doesn't know
	 * about a feature in either the compatible or incompatible
	 * feature set, it must abort and not try to meddle with
	 * things it doesn't understand...
	 */
	ULONG	s_first_ino; 		/* First non-reserved inode */
	USHORT  s_inode_size; 		/* size of inode structure */
	USHORT	s_block_group_nr; 	/* block group # of this superblock */
	ULONG	s_feature_compat; 	/* compatible feature set */
	ULONG	s_feature_incompat; 	/* incompatible feature set */
	ULONG	s_feature_ro_compat; 	/* readonly-compatible feature set */
	ULONG	s_reserved[230];	/* Padding to the end of the block */
} EXT2_SUPER_BLOCK, *PEXT2_SUPER_BLOCK;

/*
 * Codes for operating systems
 */
#define EXT2_OS_LINUX		0
#define EXT2_OS_HURD		1
#define EXT2_OS_MASIX		2
#define EXT2_OS_FREEBSD		3
#define EXT2_OS_LITES		4

/*
 * Revision levels
 */
#define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
#define EXT2_DYNAMIC_REV	1 	/* V2 format w/ dynamic inode sizes */

#define EXT2_CURRENT_REV	EXT2_GOOD_OLD_REV
#define EXT2_MAX_SUPP_REV	EXT2_DYNAMIC_REV

/*
 * The second extended file system magic number
 */
#define EXT2_SUPER_MAGIC	0xEF53

#define EXT2_MIN_BLOCK  1024
#define EXT2_MIN_FRAG   1024

/*
 * (Your local time - GMT) *3600 
 */
#define TIMEZONEDIFF    7200
#define TIMEZONE    TIMEZONEDIFF+14400

/*
 * Constants relative to the data blocks
 */
#define	EXT2_NDIR_BLOCKS		12
#define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
#define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
#define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
#define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)

/*
 * Structure of an inode on the disk
 */
typedef struct ext2_inode {
	USHORT	i_mode;		/* File mode */
	USHORT	i_uid;		/* Owner Uid */
	ULONG	i_size;		/* Size in bytes */
	ULONG	i_atime;	/* Access time */
	ULONG	i_ctime;	/* Creation time */
	ULONG	i_mtime;	/* Modification time */
	ULONG	i_dtime;	/* Deletion Time */
	USHORT	i_gid;		/* Group Id */
	USHORT	i_links_count;	/* Links count */
	ULONG	i_blocks;	/* Blocks count */
	ULONG	i_flags;	/* File flags */
	union {
		struct {
			ULONG  l_i_reserved1;
		} linux1;
		struct {
			ULONG  h_i_translator;
		} hurd1;
		struct {
			ULONG  m_i_reserved1;
		} masix1;
	} osd1;				/* OS dependent 1 */
	ULONG	i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
	ULONG	i_version;	/* File version (for NFS) */
	ULONG	i_file_acl;	/* File ACL */
	ULONG	i_dir_acl;	/* Directory ACL */
	ULONG	i_faddr;	/* Fragment address */
	union {
		struct {
			UCHAR	l_i_frag;	/* Fragment number */
			UCHAR	l_i_fsize;	/* Fragment size */
			USHORT	i_pad1;
			ULONG	l_i_reserved2[2];
		} linux2;
		struct {
			UCHAR	h_i_frag;	/* Fragment number */
			UCHAR	h_i_fsize;	/* Fragment size */
			USHORT	h_i_mode_high;
			USHORT	h_i_uid_high;
			USHORT	h_i_gid_high;
			ULONG	h_i_author;
		} hurd2;
		struct {
			UCHAR	m_i_frag;	/* Fragment number */
			UCHAR	m_i_fsize;	/* Fragment size */
			USHORT	m_pad1;
			ULONG	m_i_reserved2[2];
		} masix2;
	} osd2;				/* OS dependent 2 */
} EXT2_INODE, *PEXT2_INODE;

#if defined(__KERNEL__) || defined(__linux__)
#define i_reserved1	osd1.linux1.l_i_reserved1
#define i_frag		osd2.linux2.l_i_frag
#define i_fsize		osd2.linux2.l_i_fsize
#define i_reserved2	osd2.linux2.l_i_reserved2
#endif

#ifdef	__hurd__
#define i_translator	osd1.hurd1.h_i_translator
#define i_frag		osd2.hurd2.h_i_frag;
#define i_fsize		osd2.hurd2.h_i_fsize;
#define i_uid_high	osd2.hurd2.h_i_uid_high
#define i_gid_high	osd2.hurd2.h_i_gid_high
#define i_author	osd2.hurd2.h_i_author
#endif

#ifdef	__masix__
#define i_reserved1	osd1.masix1.m_i_reserved1
#define i_frag		osd2.masix2.m_i_frag
#define i_fsize		osd2.masix2.m_i_fsize
#define i_reserved2	osd2.masix2.m_i_reserved2
#endif

/*
 * Inode flags
 */

#define S_IFMT   0x0F000			/*017 0000 */

#define S_IFSOCK 0x0C000			/*014 0000 */
#define S_IFLNK  0x0A000			/*012 0000 */
#define S_IFFIL  0x08000			/*010 0000 */
#define S_IFBLK  0x06000			/*006 0000 */
#define S_IFDIR  0x04000			/*004 0000 */
#define S_IFCHR  0x02000			/*002 0000 */
#define S_IFIFO  0x01000			/*001 0000 */

#define S_ISSOCK(m)     (((m) & S_IFMT) == S_IFSOCK)
#define S_ISLNK(m)      (((m) & S_IFMT) == S_IFLNK)
#define S_ISFIL(m)      (((m) & S_IFMT) == S_IFFIL)
#define S_ISBLK(m)      (((m) & S_IFMT) == S_IFBLK)
#define S_ISDIR(m)      (((m) & S_IFMT) == S_IFDIR)
#define S_ISCHR(m)      (((m) & S_IFMT) == S_IFCHR)
#define S_ISFIFO(m)     (((m) & S_IFMT) == S_IFIFO)

/*not yet supported: */
#define S_IFUID  0x00800			/*000 4000 */
#define S_IFGID  0x00400			/*000 2000 */
#define S_IFVTX  0x00200			/*000 1000 */

#define	EXT2_SECRM_FL			0x00000001 /* Secure deletion */
#define	EXT2_UNRM_FL			0x00000002 /* Undelete */
#define	EXT2_COMPR_FL			0x00000004 /* Compress file */
#define EXT2_SYNC_FL			0x00000008 /* Synchronous updates */
#define EXT2_IMMUTABLE_FL		0x00000010 /* Immutable file */
#define EXT2_APPEND_FL			0x00000020 /* writes to file may only append */
#define EXT2_NODUMP_FL			0x00000040 /* do not dump file */
#define EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */

/*
 * Structure of a blocks group descriptor
 */
typedef struct ext2_group_desc
{
	ULONG	bg_block_bitmap;		/* Blocks bitmap block */
	ULONG	bg_inode_bitmap;		/* Inodes bitmap block */
	ULONG	bg_inode_table;		/* Inodes table block */
	USHORT	bg_free_blocks_count;	/* Free blocks count */
	USHORT	bg_free_inodes_count;	/* Free inodes count */
	USHORT	bg_used_dirs_count;	/* Directories count */
	USHORT	bg_pad;
	ULONG	bg_reserved[3];
} EXT2_GROUP_DESC, *PEXT2_GROUP_DESC;

#define EXT2_NAME_LEN 255

typedef struct ext2_dir_entry {
	ULONG	inode;			/* Inode number */
	USHORT	rec_len;		/* Directory entry length */
	USHORT	name_len;		/* Name length */
	char	name[EXT2_NAME_LEN];	/* File name */
} EXT2_DIR_ENTRY, *PEXT2_DIR_ENTRY;

/* File System releated ******************************************************/

#define DRIVER_NAME     "Ext2fs"
#define DEVICE_NAME     L"\\Ext2fs"
#if DBG
#define DOS_DEVICE_NAME L"\\DosDevices\\Ext2fs"
#endif

#define IOCTL_PREPARE_TO_UNLOAD \
CTL_CODE(FILE_DEVICE_UNKNOWN, 2048, METHOD_NEITHER, FILE_WRITE_ACCESS)


//
// EXT2_IDENTIFIER_TYPE
//
// Identifiers used to mark the structures
//
typedef enum _EXT2_IDENTIFIER_TYPE {
	FGD = ':DGF',
	VCB = ':BCV',
	FCB = ':BCF',
	CCB = ':BCC',
	ICX = ':XCI',
	FSD = ':DSF'
} EXT2_IDENTIFIER_TYPE;

//
// EXT2_IDENTIFIER
//
// Header used to mark the structures
//
typedef struct _EXT2_IDENTIFIER {
	EXT2_IDENTIFIER_TYPE     Type;
	ULONG                    Size;
} EXT2_IDENTIFIER, *PEXT2_IDENTIFIER;

//
// EXT2_GLOBAL_DATA
//
// Data that is not specific to a mounted volume
//
typedef struct _EXT2_GLOBAL {
	
	// Identifier for this structure
	EXT2_IDENTIFIER             Identifier;
	
	// Syncronization primitive for this structure
	ERESOURCE                   Resource;
	
	// Table of pointers to the fast I/O entry points
	FAST_IO_DISPATCH            FastIoDispatch;
	
	// Table of pointers to the Cache Manager callbacks
	CACHE_MANAGER_CALLBACKS     CacheManagerCallbacks;
	
	// Pointer to the driver object
	PDRIVER_OBJECT              DriverObject;
	
	// Pointer to the main device object
	PDEVICE_OBJECT              DeviceObject;
	
	// List of mounted volumes
	LIST_ENTRY                  VcbList;
	
	// Global flags for the driver
	ULONG                       Flags;
	
	LARGE_INTEGER				TimeZone;
	
} EXT2_GLOBAL, *PEXT2_GLOBAL;

//
// Flags for EXT2_GLOBAL_DATA
//
#define EXT2_UNLOAD_PENDING 0x00000001

//
// Driver Extension define
//
typedef struct {
	EXT2_GLOBAL	Ext2Global;
} EXT2FS_EXT, *PEXT2FS_EXT;

//
// EXT2_VCB Volume Control Block
//
// Data that represents a mounted logical volume
// It is allocated as the device extension of the volume device object
//
typedef struct _EXT2_VCB {
	
	// FCB header required by NT
	// The VCB is also used as an FCB for file objects
	// that represents the volume itself
	FSRTL_COMMON_FCB_HEADER     CommonFCBHeader;
	SECTION_OBJECT_POINTERS     SectionObject;
	ERESOURCE                   MainResource;
	ERESOURCE                   PagingIoResource;
	// end FCB header required by NT
	
	// Identifier for this structure
	EXT2_IDENTIFIER              Identifier;
	
	LIST_ENTRY                  Next;
	
	// Incremented on IRP_MJ_CREATE, decremented on IRP_MJ_CLEANUP
	// for files on this volume.
	ULONG                       OpenFileHandleCount;
	
	// Incremented on IRP_MJ_CREATE, decremented on IRP_MJ_CLOSE
	// for both files on this volume and open instances of the
	// volume itself.
	ULONG                       ReferenceCount;
	
	// Pointer to the VPB in the target device object
	PVPB                        Vpb;
	
#ifndef EXT2_RO
	
	// If the volume is mounted read only
	BOOLEAN                     ReadOnly;
	
#endif
	
	// List of FCBs for open files on this volume
	LIST_ENTRY                  FcbList;
	
	// This volumes device object
	PDEVICE_OBJECT              DeviceObject;
	
	// The physical device object (the disk)
	PDEVICE_OBJECT              TargetDeviceObject;
	
	// Information about the physical device object
	DISK_GEOMETRY               DiskGeometry;
	PARTITION_INFORMATION       PartitionInformation;
	
	// Pointer to the file system superblock
	PEXT2_SUPER_BLOCK		ext2_super_block;
	PEXT2_GROUP_DESC		ext2_group_desc;
	
	// Number of Group Decsciptions
	ULONG			ext2_groups;
	
	// Block and fragment size
	ULONG			ext2_block;
	ULONG			ext2_frag;
	
	// Flags for the volume
	ULONG                       Flags;
	
} EXT2_VCB, *PEXT2_VCB;

//
// Flags for EXT2_VCB
//
#define VCB_VOLUME_LOCKED       0x00000001
#define VCB_DISMOUNT_PENDING    0x00000002

//
// EXT2_FCB File Control Block
//
// Data that represents an open file
// There is a single instance of the FCB for every open file
//
typedef struct _EXT2_FCB {
	
	// FCB header required by NT
	FSRTL_COMMON_FCB_HEADER         CommonFCBHeader;
	SECTION_OBJECT_POINTERS         SectionObject;
	ERESOURCE                       MainResource;
	ERESOURCE                       PagingIoResource;
	// end FCB header required by NT
	
	// Identifier for this structure
	EXT2_IDENTIFIER                  Identifier;
	
	// List of FCBs for this volume
	LIST_ENTRY                      Next;
	
#ifndef EXT2_RO
	
	// Share Access for the file object
	SHARE_ACCESS                    ShareAccess;
	
#endif
	// List of byte-range locks for this file
	FILE_LOCK_ANCHOR                FileLockAnchor;

	// Incremented on IRP_MJ_CREATE, decremented on IRP_MJ_CLEANUP
	ULONG                           OpenHandleCount;
	
	// Incremented on IRP_MJ_CREATE, decremented on IRP_MJ_CLOSE
	ULONG                           ReferenceCount;
	
#ifndef EXT2_RO
	
	// If the file is a page file
	BOOLEAN                         IsPageFile;
	
	// If the file is to be deleted
	BOOLEAN                         DeletePending;
	
#endif
	
	// The filename
	UNICODE_STRING                  FileName;
	
#if DBG
	
	// Non unicode filename for use in debug prints
	PUCHAR                          DbgFileName;
	
#endif
	
	// The file attributes
	ULONG                           FileAttributes;
	
	// The offset in it's directory
	LARGE_INTEGER                   IndexNumber;
	
	// Pointer to the inode
	struct ext2_inode*              ext2_inode;
	
	// Inode number and it's directory's inode number
	ULONG			    inode;
	ULONG			    dir_inode;
	
} EXT2_FCB, *PEXT2_FCB;

//
// EXT2_CCB Context Control Block
//
// Data that represents one instance of an open file
// There is one instance of the CCB for every instance of an open file
//