win32_io.c

添加linux下对NTFS格式文件系统访问支持的源代码ntfs-3g

/*
 * win32_io.c - A stdio-like disk I/O implementation for low-level disk access
 *		on Win32.  Can access an NTFS volume while it is mounted.
 *		Originated from the Linux-NTFS project.
 *
 * Copyright (c) 2003-2004 Lode Leroy
 * Copyright (c) 2003-2006 Anton Altaparmakov
 * Copyright (c) 2004-2005 Yuval Fledel
 *
 * This program/include file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (in the main directory of the NTFS-3G
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#ifdef HAVE_WINDOWS_H
#include <windows.h>
#endif
#include <winioctl.h>

#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

/* Prevent volume.h from being be loaded, as it conflicts with winnt.h. */
#define _NTFS_VOLUME_H
struct ntfs_volume;
typedef struct ntfs_volume ntfs_volume;

#include "debug.h"
#include "types.h"
#include "device.h"

#ifndef NTFS_BLOCK_SIZE
#define NTFS_BLOCK_SIZE		512
#define NTFS_BLOCK_SIZE_BITS	9
#endif

#ifndef IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS
#define IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS 5636096
#endif

/* Windows 2k+ imports. */
typedef HANDLE (WINAPI *LPFN_FINDFIRSTVOLUME)(LPTSTR, DWORD);
typedef BOOL (WINAPI *LPFN_FINDNEXTVOLUME)(HANDLE, LPTSTR, DWORD);
typedef BOOL (WINAPI *LPFN_FINDVOLUMECLOSE)(HANDLE);
typedef BOOL (WINAPI *LPFN_SETFILEPOINTEREX)(HANDLE, LARGE_INTEGER,
		PLARGE_INTEGER, DWORD);

static LPFN_FINDFIRSTVOLUME fnFindFirstVolume = NULL;
static LPFN_FINDNEXTVOLUME fnFindNextVolume = NULL;
static LPFN_FINDVOLUMECLOSE fnFindVolumeClose = NULL;
static LPFN_SETFILEPOINTEREX fnSetFilePointerEx = NULL;

#ifdef UNICODE
#define FNPOSTFIX "W"
#else
#define FNPOSTFIX "A"
#endif

/**
 * struct win32_fd -
 */
typedef struct {
	HANDLE handle;
	s64 pos;		/* Logical current position on the volume. */
	s64 part_start;
	s64 part_length;
	int part_hidden_sectors;
	s64 geo_size, geo_cylinders;
	DWORD geo_sectors, geo_heads;
	HANDLE vol_handle;
} win32_fd;

/**
 * ntfs_w32error_to_errno - convert a win32 error code to the unix one
 * @w32error:	the win32 error code
 *
 * Limited to a relatively small but useful number of codes.
 */
static int ntfs_w32error_to_errno(unsigned int w32error)
{
	ntfs_log_trace("Converting w32error 0x%x.\n",w32error);
	switch (w32error) {
		case ERROR_INVALID_FUNCTION:
			return EBADRQC;
		case ERROR_FILE_NOT_FOUND:
		case ERROR_PATH_NOT_FOUND:
		case ERROR_INVALID_NAME:
			return ENOENT;
		case ERROR_TOO_MANY_OPEN_FILES:
			return EMFILE;
		case ERROR_ACCESS_DENIED:
			return EACCES;
		case ERROR_INVALID_HANDLE:
			return EBADF;
		case ERROR_NOT_ENOUGH_MEMORY:
			return ENOMEM;
		case ERROR_OUTOFMEMORY:
			return ENOSPC;
		case ERROR_INVALID_DRIVE:
		case ERROR_BAD_UNIT:
			return ENODEV;
		case ERROR_WRITE_PROTECT:
			return EROFS;
		case ERROR_NOT_READY:
		case ERROR_SHARING_VIOLATION:
			return EBUSY;
		case ERROR_BAD_COMMAND:
			return EINVAL;
		case ERROR_SEEK:
		case ERROR_NEGATIVE_SEEK:
			return ESPIPE;
		case ERROR_NOT_SUPPORTED:
			return EOPNOTSUPP;
		case ERROR_BAD_NETPATH:
			return ENOSHARE;
		default:
			/* generic message */
			return ENOMSG;
	}
}

/**
 * libntfs_SetFilePointerEx - emulation for SetFilePointerEx()
 *
 * We use this to emulate SetFilePointerEx() when it is not present.  This can
 * happen since SetFilePointerEx() only exists in Win2k+.
 */
static BOOL WINAPI libntfs_SetFilePointerEx(HANDLE hFile,
		LARGE_INTEGER liDistanceToMove,
		PLARGE_INTEGER lpNewFilePointer, DWORD dwMoveMethod)
{
	liDistanceToMove.LowPart = SetFilePointer(hFile,
			liDistanceToMove.LowPart, &liDistanceToMove.HighPart,
			dwMoveMethod);
	if (liDistanceToMove.LowPart == INVALID_SET_FILE_POINTER &&
			GetLastError() != NO_ERROR) {
		if (lpNewFilePointer)
			lpNewFilePointer->QuadPart = -1;
		return FALSE;
	}
	if (lpNewFilePointer)
		lpNewFilePointer->QuadPart = liDistanceToMove.QuadPart;
	return TRUE;
}

/**
 * ntfs_device_win32_init_imports - initialize the function pointers
 *
 * The Find*Volume and SetFilePointerEx functions exist only on win2k+, as such
 * we cannot just staticly import them.
 *
 * This function initializes the imports if the functions do exist and in the
 * SetFilePointerEx case, we emulate the function ourselves if it is not
 * present.
 *
 * Note: The values are cached, do be afraid to run it more than once.
 */
static void ntfs_device_win32_init_imports(void)
{
	HMODULE kernel32 = GetModuleHandle("kernel32");
	if (!kernel32) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("kernel32.dll could not be imported.\n");
	}
	if (!fnSetFilePointerEx) {
		if (kernel32)
			fnSetFilePointerEx = (LPFN_SETFILEPOINTEREX)
					GetProcAddress(kernel32,
					"SetFilePointerEx");
		/*
		 * If we did not get kernel32.dll or it is not Win2k+, emulate
		 * SetFilePointerEx().
		 */
		if (!fnSetFilePointerEx) {
			ntfs_log_debug("SetFilePonterEx() not found in "
					"kernel32.dll: Enabling emulation.\n");
			fnSetFilePointerEx = libntfs_SetFilePointerEx;
		}
	}
	/* Cannot do lookups if we could not get kernel32.dll... */
	if (!kernel32)
		return;
	if (!fnFindFirstVolume)
		fnFindFirstVolume = (LPFN_FINDFIRSTVOLUME)
				GetProcAddress(kernel32, "FindFirstVolume"
				FNPOSTFIX);
	if (!fnFindNextVolume)
		fnFindNextVolume = (LPFN_FINDNEXTVOLUME)
				GetProcAddress(kernel32, "FindNextVolume"
				FNPOSTFIX);
	if (!fnFindVolumeClose)
		fnFindVolumeClose = (LPFN_FINDVOLUMECLOSE)
				GetProcAddress(kernel32, "FindVolumeClose");
}

/**
 * ntfs_device_unix_status_flags_to_win32 - convert unix->win32 open flags
 * @flags:	unix open status flags
 *
 * Supported flags are O_RDONLY, O_WRONLY and O_RDWR.
 */
static __inline__ int ntfs_device_unix_status_flags_to_win32(int flags)
{
	int win_mode;

	switch (flags & O_ACCMODE) {
	case O_RDONLY:
		win_mode = FILE_READ_DATA;
		break;
	case O_WRONLY:
		win_mode = FILE_WRITE_DATA;
		break;
	case O_RDWR:
		win_mode = FILE_READ_DATA | FILE_WRITE_DATA;
		break;
	default:
		/* error */
		ntfs_log_trace("Unknown status flags.\n");
		win_mode = 0;
	}
	return win_mode;
}


/**
 * ntfs_device_win32_simple_open_file - just open a file via win32 API
 * @filename:	name of the file to open
 * @handle:	pointer the a HANDLE in which to put the result
 * @flags:	unix open status flags
 * @locking:	will the function gain an exclusive lock on the file?
 *
 * Supported flags are O_RDONLY, O_WRONLY and O_RDWR.
 *
 * Return 0 if o.k.
 *	 -1 if not, and errno set.  In this case handle is trashed.
 */
static int ntfs_device_win32_simple_open_file(const char *filename,
		HANDLE *handle, int flags, BOOL locking)
{
	*handle = CreateFile(filename,
			ntfs_device_unix_status_flags_to_win32(flags),
			locking ? 0 : (FILE_SHARE_WRITE | FILE_SHARE_READ),
			NULL, OPEN_EXISTING, 0, NULL);
	if (*handle == INVALID_HANDLE_VALUE) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("CreateFile(%s) failed.\n", filename);
		return -1;
	}
	return 0;
}

/**
 * ntfs_device_win32_lock - lock the volume
 * @handle:	a win32 HANDLE for a volume to lock
 *
 * Locking a volume means no one can access its contents.
 * Exiting the process automatically unlocks the volume, except in old NT4s.
 *
 * Return 0 if o.k.
 *	 -1 if not, and errno set.
 */
static int ntfs_device_win32_lock(HANDLE handle)
{
	DWORD i;

	if (!DeviceIoControl(handle, FSCTL_LOCK_VOLUME, NULL, 0, NULL, 0, &i,
			NULL)) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't lock volume.\n");
		return -1;
	}
	ntfs_log_debug("Volume locked.\n");
	return 0;
}

/**
 * ntfs_device_win32_unlock - unlock the volume
 * @handle:	the win32 HANDLE which the volume was locked with
 *
 * Return 0 if o.k.
 *	 -1 if not, and errno set.
 */
static int ntfs_device_win32_unlock(HANDLE handle)
{
	DWORD i;

	if (!DeviceIoControl(handle, FSCTL_UNLOCK_VOLUME, NULL, 0, NULL, 0, &i,
			NULL)) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't unlock volume.\n");
		return -1;
	}
	ntfs_log_debug("Volume unlocked.\n");
	return 0;
}

/**
 * ntfs_device_win32_dismount - dismount a volume
 * @handle:	a win32 HANDLE for a volume to dismount
 *
 * Dismounting means the system will refresh the volume in the first change it
 * gets.  Usefull after altering the file structures.
 * The volume must be locked by the current process while dismounting.
 * A side effect is that the volume is also unlocked, but you must not rely om
 * this.
 *
 * Return 0 if o.k.
 *	 -1 if not, and errno set.
 */
static int ntfs_device_win32_dismount(HANDLE handle)
{
	DWORD i;

	if (!DeviceIoControl(handle, FSCTL_DISMOUNT_VOLUME, NULL, 0, NULL, 0,
			&i, NULL)) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't dismount volume.\n");
		return -1;
	}
	ntfs_log_debug("Volume dismounted.\n");
	return 0;
}

/**
 * ntfs_device_win32_getsize - get file size via win32 API
 * @handle:	pointer the file HANDLE obtained via open
 *
 * Only works on ordinary files.
 *
 * Return The file size if o.k.
 *	 -1 if not, and errno set.
 */
static s64 ntfs_device_win32_getsize(HANDLE handle)
{
	DWORD loword, hiword;

	loword = GetFileSize(handle, &hiword);
	if (loword == INVALID_FILE_SIZE) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't get file size.\n");
		return -1;
	}
	return ((s64)hiword << 32) + loword;
}

/**
 * ntfs_device_win32_getdisklength - get disk size via win32 API
 * @handle:	pointer the file HANDLE obtained via open
 * @argp:	pointer to result buffer
 *
 * Only works on PhysicalDriveX type handles.
 *
 * Return The disk size if o.k.
 *	 -1 if not, and errno set.
 */
static s64 ntfs_device_win32_getdisklength(HANDLE handle)
{
	GET_LENGTH_INFORMATION buf;
	DWORD i;

	if (!DeviceIoControl(handle, IOCTL_DISK_GET_LENGTH_INFO, NULL, 0, &buf,
			sizeof(buf), &i, NULL)) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't get disk length.\n");
		return -1;
	}
	ntfs_log_debug("Disk length: %lld.\n", buf.Length.QuadPart);
	return buf.Length.QuadPart;
}

/**
 * ntfs_device_win32_getntfssize - get NTFS volume size via win32 API
 * @handle:	pointer the file HANDLE obtained via open
 * @argp:	pointer to result buffer
 *
 * Only works on NTFS volume handles.
 * An annoying bug in windows is that an NTFS volume does not occupy the entire
 * partition, namely not the last sector (which holds the backup boot sector,
 * and normally not interesting).
 * Use this function to get the length of the accessible space through a given
 * volume handle.
 *
 * Return The volume size if o.k.
 *	 -1 if not, and errno set.
 */
static s64 ntfs_device_win32_getntfssize(HANDLE handle)
{
	s64 rvl;
#ifdef FSCTL_GET_NTFS_VOLUME_DATA
	DWORD i;
	NTFS_VOLUME_DATA_BUFFER buf;

	if (!DeviceIoControl(handle, FSCTL_GET_NTFS_VOLUME_DATA, NULL, 0, &buf,
			sizeof(buf), &i, NULL)) {
		errno = ntfs_w32error_to_errno(GetLastError());
		ntfs_log_trace("Couldn't get NTFS volume length.\n");
		return -1;
	}
	rvl = buf.NumberSectors.QuadPart * buf.BytesPerSector;
	ntfs_log_debug("NTFS volume length: 0x%llx.\n", (long long)rvl);
#else
	errno = EINVAL;
	rvl = -1;
#endif
	return rvl;
}

/**
 * ntfs_device_win32_getgeo - get CHS information of a drive
 * @handle:	an open handle to the PhysicalDevice
 * @fd:		a win_fd structure that will be filled
 *
 * Return 0 if o.k.
 *	 -1 if not, and errno  set.
 *
 * In Windows NT+: fills size, sectors, and cylinders and sets heads to -1.
 * In Windows XP+: fills size, sectors, cylinders, and heads.
 *
 * Note: In pre XP, this requires write permission, even though nothing is
 * actually written.
 *
 * If fails, sets sectors, cylinders, heads, and size to -1.
 */
static int ntfs_device_win32_getgeo(HANDLE handle, win32_fd *fd)
{
	DWORD i;
	BOOL rvl;
	BYTE b[sizeof(DISK_GEOMETRY) + sizeof(DISK_PARTITION_INFO) +
			sizeof(DISK_DETECTION_INFO) + 512];

	rvl = DeviceIoControl(handle, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX, NULL,
			0, &b, sizeof(b), &i, NULL);
	if (rvl) {
		ntfs_log_debug("GET_DRIVE_GEOMETRY_EX detected.\n");
		DISK_DETECTION_INFO *ddi = (PDISK_DETECTION_INFO)
				(((PBYTE)(&((PDISK_GEOMETRY_EX)b)->Data)) +
				(((PDISK_PARTITION_INFO)
				(&((PDISK_GEOMETRY_EX)b)->Data))->
				SizeOfPartitionInfo));
		fd->geo_cylinders = ((DISK_GEOMETRY*)&b)->Cylinders.QuadPart;
		fd->geo_sectors = ((DISK_GEOMETRY*)&b)->SectorsPerTrack;
		fd->geo_size = ((DISK_GEOMETRY_EX*)&b)->DiskSize.QuadPart;
		switch (ddi->DetectionType) {
		case DetectInt13:
			fd->geo_cylinders = ddi->Int13.MaxCylinders;
			fd->geo_sectors = ddi->Int13.SectorsPerTrack;
			fd->geo_heads = ddi->Int13.MaxHeads;
			return 0;
		case DetectExInt13:
			fd->geo_cylinders = ddi->ExInt13.ExCylinders;
			fd->geo_sectors = ddi->ExInt13.ExSectorsPerTrack;
			fd->geo_heads = ddi->ExInt13.ExHeads;
			return 0;
		case DetectNone:
		default:
			break;
		}
	} else
		fd->geo_heads = -1;
	rvl = DeviceIoControl(handle, IOCTL_DISK_GET_DRIVE_GEOMETRY, NULL, 0,
			&b, sizeof(b), &i, NULL);
	if (rvl) {
		ntfs_log_debug("GET_DRIVE_GEOMETRY detected.\n");
		fd->geo_cylinders = ((DISK_GEOMETRY*)&b)->Cylinders.QuadPart;
		fd->geo_sectors = ((DISK_GEOMETRY*)&b)->SectorsPerTrack;
		fd->geo_size = fd->geo_cylinders * fd->geo_sectors *
				((DISK_GEOMETRY*)&b)->TracksPerCylinder *
				((DISK_GEOMETRY*)&b)->BytesPerSector;
		return 0;