/************************************************************************
* 文件名稱:Driver.cpp                                                 
* 作    者:張帆
* 完成日期:2007-11-1
*************************************************************************/

#include "Driver.h"

/************************************************************************
* 函數名稱:DriverEntry
* 功能描述:初始化驅動程序，定位和申請硬件資源，創建內核對象
* 參數列表:
      pDriverObject:從I/O管理器中傳進來的驅動對象
      pRegistryPath:驅動程序在注冊表的中的路徑
* 返回 值:返回初始化驅動狀態
*************************************************************************/
#pragma INITCODE
extern "C" NTSTATUS DriverEntry (
			IN PDRIVER_OBJECT pDriverObject,
			IN PUNICODE_STRING pRegistryPath	) 
{
	NTSTATUS ntStatus;
	KdPrint(("DriverB:Enter B DriverEntry\n"));

	//注冊其他驅動調用函數入口
	pDriverObject->DriverUnload = HelloDDKUnload;
	pDriverObject->MajorFunction[IRP_MJ_CREATE] = HelloDDKCreate;
	pDriverObject->MajorFunction[IRP_MJ_CLOSE] = HelloDDKClose;
	pDriverObject->MajorFunction[IRP_MJ_WRITE] = HelloDDKDispatchRoutine;
	pDriverObject->MajorFunction[IRP_MJ_READ] = HelloDDKRead;
	
	//創建驅動設備對象
	ntStatus = CreateDevice(pDriverObject);

	KdPrint(("DriverB:Leave B DriverEntry\n"));
	return ntStatus;
}

/************************************************************************
* 函數名稱:CreateDevice
* 功能描述:初始化設備對象
* 參數列表:
      pDriverObject:從I/O管理器中傳進來的驅動對象
* 返回 值:返回初始化狀態
*************************************************************************/
#pragma INITCODE
NTSTATUS CreateDevice (
		IN PDRIVER_OBJECT	pDriverObject) 
{
	NTSTATUS ntStatus;
	PDEVICE_OBJECT pDevObj;
	PDEVICE_EXTENSION pDevExt;
	
	//創建設備名稱
	UNICODE_STRING devName;
	RtlInitUnicodeString(&devName,L"\\Device\\MyDDKDevicB");
	
	//創建設備
	ntStatus = IoCreateDevice( pDriverObject,
						sizeof(DEVICE_EXTENSION),
						&(UNICODE_STRING)devName,
						FILE_DEVICE_UNKNOWN,
						0, TRUE,
						&pDevObj );
	if (!NT_SUCCESS(ntStatus))
		return ntStatus;

	pDevObj->Flags |= DO_BUFFERED_IO;
	pDevExt = (PDEVICE_EXTENSION)pDevObj->DeviceExtension;
	pDevExt->pDevice = pDevObj;
	pDevExt->ustrDeviceName = devName;

	//創建符號鏈接
	UNICODE_STRING symLinkName;
	RtlInitUnicodeString(&symLinkName,L"\\??\\HelloDDKB");
	pDevExt->ustrSymLinkName = symLinkName;
	NTSTATUS status = IoCreateSymbolicLink( &symLinkName,&devName );
	if (!NT_SUCCESS(status)) 
	{
		IoDeleteDevice( pDevObj );
		return status;
	}

	return STATUS_SUCCESS;
}

/************************************************************************
* 函數名稱:HelloDDKUnload
* 功能描述:負責驅動程序的卸載操作
* 參數列表:
      pDriverObject:驅動對象
* 返回 值:返回狀態
*************************************************************************/
#pragma PAGEDCODE
VOID HelloDDKUnload (IN PDRIVER_OBJECT pDriverObject) 
{
	PDEVICE_OBJECT	pNextObj;
	KdPrint(("DriverB:Enter B DriverUnload\n"));
	pNextObj = pDriverObject->DeviceObject;

	while (pNextObj != NULL) 
	{
		PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
			pNextObj->DeviceExtension;

		//刪除符號鏈接
		UNICODE_STRING pLinkName = pDevExt->ustrSymLinkName;
		IoDeleteSymbolicLink(&pLinkName);
		pNextObj = pNextObj->NextDevice;
		IoDeleteDevice( pDevExt->pDevice );
	}
	KdPrint(("DriverB:Enter B DriverUnload\n"));
}

#pragma PAGEDCODE
NTSTATUS HelloDDKRead(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("DriverB:Enter B HelloDDKRead\n"));
	NTSTATUS ntStatus = STATUS_SUCCESS;

	UNICODE_STRING DeviceName;
	RtlInitUnicodeString( &DeviceName, L"\\Device\\MyDDKDeviceA" );

	PDEVICE_OBJECT DeviceObject = NULL;
	PFILE_OBJECT FileObject = NULL;
	//得到設備對象句柄，計數器加1
	//如果是第一次調用IoGetDeviceObjectPointer，會打開設備，相當于調用ZwCreateFile
	ntStatus = IoGetDeviceObjectPointer(&DeviceName,FILE_ALL_ACCESS,&FileObject,&DeviceObject);

	KdPrint(("DriverB:FileObject:%x\n",FileObject));
	KdPrint(("DriverB:DeviceObject:%x\n",DeviceObject));

	if (!NT_SUCCESS(ntStatus))
	{
		KdPrint(("DriverB:IoGetDeviceObjectPointer() 0x%x\n", ntStatus ));

		ntStatus = STATUS_UNSUCCESSFUL;
		// 完成IRP
		pIrp->IoStatus.Status = ntStatus;
		pIrp->IoStatus.Information = 0;	// bytes xfered
		IoCompleteRequest( pIrp, IO_NO_INCREMENT );
		KdPrint(("DriverB:Leave B HelloDDKRead\n"));

		return ntStatus;
	}

	KEVENT event;
	KeInitializeEvent(&event,NotificationEvent,FALSE);
	IO_STATUS_BLOCK status_block;
	LARGE_INTEGER offsert = RtlConvertLongToLargeInteger(0);

	//創建同步IRP
	PIRP pNewIrp = IoBuildSynchronousFsdRequest(IRP_MJ_READ,
												DeviceObject,
												NULL,0,
												&offsert,&event,&status_block);
 	KdPrint(("DriverB:pNewIrp:%x\n",pNewIrp));

	PIO_STACK_LOCATION stack = IoGetNextIrpStackLocation(pNewIrp);
	stack->FileObject = FileObject;

	//調用DriverA，會一直調用到DriverA的派遣函數
	NTSTATUS status = IoCallDriver(DeviceObject,pNewIrp);

    if (status == STATUS_PENDING) {

		//如果DriverA的派遣函數沒有完成IRP，則等待IRP完成
       status = KeWaitForSingleObject(
                            &event,
                            Executive,
                            KernelMode,
                            FALSE, // Not alertable
                            NULL);
        status = status_block.Status;
    }

	//將引用計數減1，如果此時計數器減為0，
	//則將關閉設備，相當于調用ZwClose
 	ObDereferenceObject( FileObject );


	ntStatus = STATUS_SUCCESS;
	// 完成IRP
	pIrp->IoStatus.Status = ntStatus;
	pIrp->IoStatus.Information = 0;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );
	KdPrint(("DriverB:Leave B HelloDDKRead\n"));
	return ntStatus;
}

/************************************************************************
* 函數名稱:HelloDDKDispatchRoutine
* 功能描述:對讀IRP進行處理
* 參數列表:
      pDevObj:功能設備對象
      pIrp:從IO請求包
* 返回 值:返回狀態
*************************************************************************/
#pragma PAGEDCODE
NTSTATUS HelloDDKDispatchRoutine(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("DriverB:Enter B HelloDDKDispatchRoutine\n"));
	NTSTATUS ntStatus = STATUS_SUCCESS;
	// 完成IRP
	pIrp->IoStatus.Status = ntStatus;
	pIrp->IoStatus.Information = 0;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );
	KdPrint(("DriverB:Leave B HelloDDKDispatchRoutine\n"));
	return ntStatus;
}

#pragma PAGEDCODE
NTSTATUS HelloDDKCreate(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("DriverB:Enter B HelloDDKCreate\n"));
	NTSTATUS ntStatus = STATUS_SUCCESS;
	// 完成IRP
	pIrp->IoStatus.Status = ntStatus;
	pIrp->IoStatus.Information = 0;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );

	KdPrint(("DriverB:Leave B HelloDDKCreate\n"));

	return ntStatus;
}

#pragma PAGEDCODE
NTSTATUS HelloDDKClose(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("DriverB:Enter B HelloDDKClose\n"));
	NTSTATUS ntStatus = STATUS_SUCCESS;

	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION)pDevObj->DeviceExtension;

	// 完成IRP
	pIrp->IoStatus.Status = ntStatus;
	pIrp->IoStatus.Information = 0;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );
	
	KdPrint(("DriverB:Leave B HelloDDKClose\n"));

	return ntStatus;
}