Option Explicit
On Error Resume Next
'#--------------------------------------------------------------------------------------------
'# 
'#  This VBScript is used to allow software installation and update to a Windows Embedded
'#  client that is using EWF or FBWF protection on the drive.
'#
'#  Full documentation on the use of this VBScript is included in a separate document.
'#
'#--------------------------------------------------------------------------------------------

Dim gWshShell										'WScript.Shell object
Dim strProtectedDrive : strProtectedDrive = null	 'The drive shown. by EWF or FBWF as being protected
Dim gSystemDrive									 'Contains the System Drive (e.g. C:).
Dim strDisableCommand : strDisableCommand = null	 'Either the EWF or FBWF command to disable the write filter.
Dim strEnableCommand  : strEnableCommand = null	'Either the EWF or FBWF command to enable the write filter.
Dim bIsWFEnabled : bIsWFEnabled = false			'Boolean for write filter enabled/disabled. 
Dim bIsEWFInstalled  : bIsEWFInstalled = false	 'Boolean for EWF installed.
Dim bIsFBWFInstalled : bIsFBWFInstalled = false	'Boolean for FBWF installed.
Dim strCommand : strCommand = null				 'The string holding the command-line argument.

Set gWshShell = WScript.CreateObject("WScript.Shell")	 '# Create the Shell Object.

CheckWindowsEmbedded			'# Check to ensure this script is being run on Windows Embedded.

' Check whether any command-line argument is passed, and process.
If WScript.Arguments.Count = 1 Then
	strCommand = UCase(WScript.Arguments.Item(0))
	Select Case strCommand
		Case "DISABLE"
			CheckWhichWF
			DisableWF
		Case "ENABLE"
			CheckWhichWF
			EnableWF
		Case Else
			WScript.Quit (0)
	End Select

Else
	WScript.Echo "Invalid Command Line: Missing Action Parameter"
	WScript.Echo "USAGE:"
	WScript.Echo "EWF-FBWF.vbs [Disable|Enable]"
	WScript.Quit (0)
End If


WScript.Quit (0)


'--------------------------------------------------------------------------------------------
'   CheckWindowsEmbedded
'
'   Checks to ensure this script is being run on Windows Embedded and, if not, exits.
'	 If there was no error in finding the key, read the string values from the key.
'	 If the "EmbeddedNT" string is found, this is XPe.
'	 In all other cases, bIsXPe is left as false, which causes an exit.
'--------------------------------------------------------------------------------------------
Sub CheckWindowsEmbedded()
	Dim arrValues, bIsXPe
	bIsXPe = FALSE

	arrValues = gWshShell.RegRead(XPE_REG_KEY)

	If Err.Number = 0 then
	 For Each strValue in arrValues
			if strValue = "EmbeddedNT" then
				bIsXPe = True   
			end if 
	 Next
	End If		 
	Err.Clear
   
	if not bIsXPe then
		WScript.Quit (0)
	end if
End Sub


'--------------------------------------------------------------------------------------------
'  CheckWhichWF
'
'  Determines which write filter (EWF or FBWF) is currently in use on this system and sets
'  a variable for use in other sections of this script. Because both EWF and FBWF can be on
'  a system (but not both controlling the protection of that system), simply testing for
'  the existence of the executable is not sufficient. Without using a separate C++ program
'  that accesses the EWF or FBWF API, the only way to test for which one is protecting the
'  drive is to use the output of the program at the command line to see whether it is active
'  and which drive is being protected.
'
'--------------------------------------------------------------------------------------------
Sub CheckWhichWF
	Dim oFSO, strFile, strPath, wsx
	Dim output, strLine
	Dim Status
	Set oFSO = CreateObject("Scripting.FileSystemObject") 
	
	strPath = gWshShell.ExpandEnvironmentStrings("%SystemRoot%")
	If IsEmpty(strPath) Then
		WScript.Quit (1)
	Else
		'============================================
		'					EWF
		'============================================
		'Check to see whether EWFMGR.EXE is on the system.
		strFile = strPath + "\system32\EWFMGR.EXE"
		If oFSO.FileExists(strFile) Then
			'Run the EWF Manager to see whether the drive is actually protected.
			set wsx = gWshShell.Exec("%comspec% /c " & strFile & " -all")
			Do
				Status = wsx.Status
		
				' Parsing the output of the command to see whether the EWF is enabled 
				' and which drive is being protected (if any). Typical output 
				' of this command looks like this:
				'
				'   Protected Volume Configuration
				'	 Type			RAM
				'	 State		 DISABLED
				'	 Boot Command	ENABLE
				'	 Param1		0
				'	 Param2		0
				'	 Persistent Data ""
				'	 Volume ID	 A7 FA CA 34 00 7E 00 00 00 00 00 00 00 00 00 00
				'	 Device Name	 "\Device\HarddiskVolume1" [C:]
				'	 Max Levels	1
				'	 Clump Size	512
				'	 Current Level   N/A
				'
				output = split(wsx.Stdout.ReadAll(), vbNewLine)
				For Each strLine in output
					if InStr(strLine, "State") then
						' If the output from the command generated text like the above, 
						' EWF must be installed. Now check whether it's enabled or disabled.
						bIsEWFInstalled = True				
						if InStr(strLine, "DISABLED") then
							bIsWFEnabled = false
						elseif InStr(strLine, "ENABLED") then
							bIsWfEnabled = true
						end if
					End If
				
					' Check which drive is being protected, and get the drive letter
					' because the drive letter is required in the command line.
					if (bIsEWFInstalled) AND (InStr(strLine, "Device Name")) Then
						strProtectedDrive = left(right(strLine, 3), 2)
						'Set the default commands to be used elsewhere in this script.
						strEnableCommand = strFile & " " & strProtectedDrive & " -enable"
						strDisableCommand = strFile & " " & strProtectedDrive & " -disable"
					End If
				Next

				If Status <> 0 Then Exit Do
				WScript.Sleep 10

			Loop
		End if
	
		'============================================
		'					FBWF
		'============================================
		'If EWF is enabled, FBWF cannot be enabled, so if EWF enabled, skip FBWF.
		If (Not bIsWFEnabled) Then
			Dim bCurrentState : bCurrentState = false
			Dim intLoopNum : intLoopNum = 0

			'Check to see whether FBWFMGR.EXE is on the system.
			strFile = strPath + "\system32\FBWFMGR.EXE"
			If oFSO.FileExists(strFile) Then
				'Run the FBWF Manager to see whether the drive is actually protected.
				set wsx = gWshShell.Exec("%comspec% /c " & strFile & " /displayconfig")
				Do
					Status = wsx.Status
				
					' Parsing the output of the command to see whether the EWF is enabled 
					' and which drive is being protected (if any). Typical output 
					' of this command looks like this:
					'
					'   File-based write filter configuration for the current session:
					'	 filter state: disabled.
					'
					'   File-based write filter configuration for the next session:
					'	 filter state: enabled.
					'	 overlay cache data compression state: disabled.
					'	 overlay cache threshold: 64 MB.
					'	 overlay cache pre-allocation: enabled.
					'	 protected volume list:
					'	 \Device\HarddiskVolume1
					'	 write-through list of each protected volume:
					'	 \Device\HarddiskVolume1: (none)
					'
					output = split(wsx.Stdout.ReadAll(), vbNewLine)
					For Each strLine in output
						if InStr(strLine, "current session:") then
							' If the output from the command generated text like the above, 
							' EWF must be installed. Now check whether it's enabled or disabled.
							bIsFBWFInstalled = True
						
						 ' Gathering data from the current session (not the next session).
						 bCurrentState = true
						elseif InStr(strLine, "next session:") then
							bCurrentState = false
							bNextState = true
						end if
				
						' If the Current State / filter state = enabled, FBWF is enabled.
						if (bCurrentState) AND (InStr(strLine, "filter state:")) then
							if (InStr(strLine, "enabled")) then
								bIsWFEnabled = true
							else
								bIsWFEnabled = false
							end if
							Exit For
						end if
					Next
					If Status <> 0 Then Exit Do
					WScript.Sleep 10
				Loop
				'Set the default commands to be used elsewhere in this script.
				if bIsFBWFInstalled then
					strEnableCommand = strFile & " /enable"
					strDisableCommand = strFile & " /disable"
				End if
			End if	
		End if
	End If
End Sub


'--------------------------------------------------------------------------------------------
'   DisableWF
'
'   This sub is used to disable the write filter on the drive (EWF or FBWF) so that updates
'   can be written to the storage device.
'
'   If the drive is already disabled, this subroutine does nothing but just return. Otherwise,
'   the function will disable the EWF and reboot the machine.
'
'--------------------------------------------------------------------------------------------
Sub DisableWF
		Dim oExec

		'If the write filter is enabled, disable it.
		if bIsWFEnabled then
			Set oExec = gWshShell.Exec(strDisableCommand)
			'Wait for the previous command to complete.
			Do While oExec.Status = 0
				WScript.Sleep 100
			Loop
	
			'Reboot the machine to complete the operation.
			RebootEx 0
	End If
End Sub



'--------------------------------------------------------------------------------------------
'   EnableWF
'
'   This sub is used to enable the write filter on the drive (EWF or FBWF).
'
'   The function will enable the EWF and reboot the machine in two minutes so that task sequence 
'   will have time to clean up itself.
'
'--------------------------------------------------------------------------------------------
Sub EnableWF
		Dim oExec

		' If the write filter is installed, enable it.
		if (bIsEWFInstalled OR bIsFBWFInstalled) then
			Set oExec = gWshShell.Exec(strEnableCommand)
			' Wait for the previous command to complete.
			Do While oExec.Status = 0
		
				WScript.Sleep 100
			Loop
	
			'Reboot the machine to complete the operation.
			RebootEx 120
	End If
End Sub


'--------------------------------------------------------------------------------------------
'	RebootEx
' 
'   This sub reboots the system.
'--------------------------------------------------------------------------------------------
Sub RebootEx(intSeconds)

	 Dim strRebootCommandLine

	 strRebootCommandLine = "shutdown.exe -r -t " & intSeconds
	 
	Set oExec = gWshShell.Exec(strRebootCommandLine)

	Do While oExec.Status = 0
			WScript.Sleep 100
	Loop
End Sub