/************************************************************************
* 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 status;
	KdPrint(("Enter DriverEntry\n"));

	//設置卸載函數
	pDriverObject->DriverUnload = HelloDDKUnload;

	//設置派遣函數
	for (int i = 0; i < arraysize(pDriverObject->MajorFunction); ++i)
		pDriverObject->MajorFunction[i] = HelloDDKDispatchRoutin;
	pDriverObject->MajorFunction[IRP_MJ_READ] = HelloDDKRead;
	
	//創建驅動設備對象
	status = CreateDevice(pDriverObject);

	KdPrint(("Leave DriverEntry\n"));
	return status;
}

/************************************************************************
* 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 status;
	PDEVICE_OBJECT pDevObj;
	PDEVICE_EXTENSION pDevExt;
	
	//創建設備名稱
	UNICODE_STRING devName;
	RtlInitUnicodeString(&devName,L"\\Device\\MyDDKDevice");
	
	//創建設備
	status = IoCreateDevice( pDriverObject,
						sizeof(DEVICE_EXTENSION),
						&(UNICODE_STRING)devName,
						FILE_DEVICE_UNKNOWN,
						0, TRUE,
						&pDevObj );
	if (!NT_SUCCESS(status))
		return status;

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

	//申請模擬文件的緩沖區
	pDevExt->buffer = (PUCHAR)ExAllocatePool(PagedPool,MAX_FILE_LENGTH);
	//設置模擬文件大小
	pDevExt->file_length = 0;

	//創建符號鏈接
	UNICODE_STRING symLinkName;
	RtlInitUnicodeString(&symLinkName,L"\\??\\HelloDDK");
	pDevExt->ustrSymLinkName = symLinkName;
	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(("Enter DriverUnload\n"));
	pNextObj = pDriverObject->DeviceObject;
	while (pNextObj != NULL) 
	{
		PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
			pNextObj->DeviceExtension;
		if (pDevExt->buffer)
		{
			ExFreePool(pDevExt->buffer);
			pDevExt->buffer = NULL;
		}

		//刪除符號鏈接
		UNICODE_STRING pLinkName = pDevExt->ustrSymLinkName;
		IoDeleteSymbolicLink(&pLinkName);
		pNextObj = pNextObj->NextDevice;
		IoDeleteDevice( pDevExt->pDevice );
	}
}

/************************************************************************
* 函數名稱:HelloDDKDispatchRoutin
* 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 HelloDDKDispatchRoutin(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("Enter HelloDDKDispatchRoutin\n"));

	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(pIrp);
	//建立一個字符串數組與IRP類型對應起來
	static char* irpname[] = 
	{
		"IRP_MJ_CREATE",
		"IRP_MJ_CREATE_NAMED_PIPE",
		"IRP_MJ_CLOSE",
		"IRP_MJ_READ",
		"IRP_MJ_WRITE",
		"IRP_MJ_QUERY_INFORMATION",
		"IRP_MJ_SET_INFORMATION",
		"IRP_MJ_QUERY_EA",
		"IRP_MJ_SET_EA",
		"IRP_MJ_FLUSH_BUFFERS",
		"IRP_MJ_QUERY_VOLUME_INFORMATION",
		"IRP_MJ_SET_VOLUME_INFORMATION",
		"IRP_MJ_DIRECTORY_CONTROL",
		"IRP_MJ_FILE_SYSTEM_CONTROL",
		"IRP_MJ_DEVICE_CONTROL",
		"IRP_MJ_INTERNAL_DEVICE_CONTROL",
		"IRP_MJ_SHUTDOWN",
		"IRP_MJ_LOCK_CONTROL",
		"IRP_MJ_CLEANUP",
		"IRP_MJ_CREATE_MAILSLOT",
		"IRP_MJ_QUERY_SECURITY",
		"IRP_MJ_SET_SECURITY",
		"IRP_MJ_POWER",
		"IRP_MJ_SYSTEM_CONTROL",
		"IRP_MJ_DEVICE_CHANGE",
		"IRP_MJ_QUERY_QUOTA",
		"IRP_MJ_SET_QUOTA",
		"IRP_MJ_PNP",
	};

	UCHAR type = stack->MajorFunction;
	if (type >= arraysize(irpname))
		KdPrint((" - Unknown IRP, major type %X\n", type));
	else
		KdPrint(("\t%s\n", irpname[type]));


	//對一般IRP的簡單操作，后面會介紹對IRP更復雜的操作
	NTSTATUS status = STATUS_SUCCESS;
	// 完成IRP
	pIrp->IoStatus.Status = status;
	pIrp->IoStatus.Information = 0;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );

	KdPrint(("Leave HelloDDKDispatchRoutin\n"));

	return status;
}

NTSTATUS HelloDDKRead(IN PDEVICE_OBJECT pDevObj,
								 IN PIRP pIrp) 
{
	KdPrint(("Enter HelloDDKRead\n"));

	PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)pDevObj->DeviceExtension;
	NTSTATUS status = STATUS_SUCCESS;

	//得到當前堆棧
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(pIrp);
	//得到讀的長度
	ULONG ulReadLength = stack->Parameters.Read.Length;
	//得到讀的偏移量
	ULONG ulReadOffset = (ULONG)stack->Parameters.Read.ByteOffset.QuadPart;
	//得到用戶模式地址
	PVOID user_address = pIrp->UserBuffer;

	KdPrint(("user_address:0X%0X\n",user_address));

	__try
	{
		KdPrint(("Enter __try block\n"));
		//判斷空指針是否可寫，顯然會導致異常
		ProbeForWrite(user_address,ulReadLength,4);

		memset(user_address,0xAA,ulReadLength);

		//由于在上面引發異常，所以以后語句不會被執行!
		KdPrint(("Leave __try block\n"));
	}
	__except(EXCEPTION_EXECUTE_HANDLER)
	{
		KdPrint(("Catch the exception\n"));
		KdPrint(("The program will keep going\n"));
		status = STATUS_UNSUCCESSFUL;
	}

	pIrp->IoStatus.Status = status;
	pIrp->IoStatus.Information = ulReadLength;	// bytes xfered
	IoCompleteRequest( pIrp, IO_NO_INCREMENT );
	KdPrint(("Leave HelloDDKRead\n"));

	return status;
}