///////////////////////////////////////////////////
// Driver.h文件

#ifndef __DRIVER_H__
#define __DRIVER_H__

#include <Winsvc.h>	// 為了使用SCM函數(shù)

class CDriver
{

public:
// 構造函數(shù)和析構函數(shù)
	// 構造函數(shù)，pszDriverPath為驅(qū)動所在目錄，pszLinkName為符號連接名字
	// 在類的構造函數(shù)中，將試圖創(chuàng)建或打開服務，
	CDriver(LPCTSTR pszDriverPath, LPCTSTR pszLinkName);
	// 析構函數(shù)。在這里，將停止服務，
	virtual ~CDriver();

// 屬性
	// 此驅(qū)動是否可用
	virtual BOOL IsValid() { return (m_hSCM != NULL && m_hService != NULL); }

// 操作
	// 開啟服務。也就是說驅(qū)動的DriverEntry函數(shù)將被調(diào)用
	virtual BOOL StartDriver();
	// 結(jié)束服務。即驅(qū)動程序的DriverUnload例程將被調(diào)用
	virtual BOOL StopDriver();
	
	// 打開設備，即取得到此驅(qū)動的一個句柄
	virtual BOOL OpenDevice();

	// 向設備發(fā)送控制代碼
	virtual DWORD IoControl(DWORD nCode, PVOID pInBuffer, 
			DWORD nInCount, PVOID pOutBuffer, DWORD nOutCount);
// 實現(xiàn)
protected:
	char m_szLinkName[56];	// 符號連接名稱

	BOOL m_bStarted;	// 指定服務是否啟動
	BOOL m_bCreateService;	// 指定是否創(chuàng)建了服務

	HANDLE m_hSCM;		// SCM數(shù)據(jù)庫句柄
	HANDLE m_hService;	// 服務句柄
	HANDLE m_hDriver;	// 設備句柄
};


CDriver::CDriver(LPCTSTR pszDriverPath, LPCTSTR pszLinkName)
{
	strncpy(m_szLinkName, pszLinkName, 55);
	m_bStarted = FALSE;
	m_bCreateService = FALSE;
	m_hSCM = m_hService = NULL;
	m_hDriver = INVALID_HANDLE_VALUE;

	// 打開SCM管理器
	m_hSCM = ::OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
	if(m_hSCM == NULL)
	{
		MessageBox(0, "打開服務控制管理器失敗\n", 
				"可能是因為您不擁有Administrator權限\n", 0);
		return;
	}

	// 創(chuàng)建或打開服務
	m_hService = ::CreateService(m_hSCM, m_szLinkName, m_szLinkName, SERVICE_ALL_ACCESS, 
				SERVICE_KERNEL_DRIVER, SERVICE_DEMAND_START, SERVICE_ERROR_NORMAL, 
				pszDriverPath, NULL, 0, NULL, NULL, NULL);
	if(m_hService == NULL)
	{
		// 創(chuàng)建服務失敗，可能是因為服務已經(jīng)存在，所以還要試圖打開它
		int nError = ::GetLastError();
		if(nError == ERROR_SERVICE_EXISTS || nError == ERROR_SERVICE_MARKED_FOR_DELETE)
		{
			m_hService = ::OpenService(m_hSCM, m_szLinkName, SERVICE_ALL_ACCESS);
		}
	}
	else
	{
		m_bCreateService = TRUE;
	}
}

CDriver::~CDriver()
{
	// 關閉設備句柄
	if(m_hDriver != INVALID_HANDLE_VALUE)
		::CloseHandle(m_hDriver);
	// 如果創(chuàng)建了服務，就將之刪除
	if(m_bCreateService)
	{
		StopDriver();
		::DeleteService(m_hService);	
	}
	// 關閉句柄
	if(m_hService != NULL)
		::CloseServiceHandle(m_hService);
	if(m_hSCM != NULL)
		::CloseServiceHandle(m_hSCM);
}

BOOL CDriver::StartDriver()
{
	if(m_bStarted)
		return TRUE;
	if(m_hService == NULL)
		return FALSE;
	// 啟動服務
	if(!::StartService(m_hService, 0, NULL))
	{
		int nError = ::GetLastError();
		if(nError == ERROR_SERVICE_ALREADY_RUNNING)
			m_bStarted = TRUE;
		else
			::DeleteService(m_hService);
	}
	else
	{
		// 啟動成功后，等待服務進入運行狀態(tài)
		int nTry = 0;
		SERVICE_STATUS ss;
		::QueryServiceStatus(m_hService, &ss);
		while(ss.dwCurrentState == SERVICE_START_PENDING && nTry++ < 80)
		{
			::Sleep(50);
			::QueryServiceStatus(m_hService, &ss);
		}
		if(ss.dwCurrentState == SERVICE_RUNNING)
			m_bStarted = TRUE;
	}
	return m_bStarted;
}

BOOL CDriver::StopDriver()
{
	if(!m_bStarted)
		return TRUE;
	if(m_hService == NULL)
		return FALSE;
	// 停止服務
	SERVICE_STATUS ss;
	if(!::ControlService(m_hService, SERVICE_CONTROL_STOP, &ss))
	{
		if(::GetLastError() == ERROR_SERVICE_NOT_ACTIVE)
			m_bStarted = FALSE;
	}
	else
	{
		// 等待服務完全停止運行
		int nTry = 0;
		while(ss.dwCurrentState == SERVICE_STOP_PENDING && nTry++ < 80)
		{
			::Sleep(50);
			::QueryServiceStatus(m_hService, &ss);
		}
		if(ss.dwCurrentState == SERVICE_STOPPED)
			m_bStarted = FALSE;
	}
	return !m_bStarted;
}

BOOL CDriver::OpenDevice()
{
	if(m_hDriver != INVALID_HANDLE_VALUE)
		return TRUE;

	// "\\.\"是Win32中定義本地計算機的方法，
	// m_szLinkName是設備對象的符號連接名稱，后面章節(jié)會詳細討論
	char sz[256] = "";
	wsprintf(sz, "\\\\.\\%s", m_szLinkName);
	// 打開驅(qū)動程序所控制設備
	m_hDriver = ::CreateFile(sz,
		GENERIC_READ | GENERIC_WRITE,
		0,
		NULL,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		NULL);

	return (m_hDriver != INVALID_HANDLE_VALUE);
}

DWORD CDriver::IoControl(DWORD nCode, PVOID pInBuffer, 
		DWORD nInCount, PVOID pOutBuffer, DWORD nOutCount)
{
	if(m_hDriver == INVALID_HANDLE_VALUE)
		return -1;
	// 向驅(qū)動程序發(fā)送控制代碼
	DWORD nBytesReturn;
	BOOL bRet = ::DeviceIoControl(m_hDriver, nCode, 
		pInBuffer, nInCount, pOutBuffer, nOutCount, &nBytesReturn, NULL);
	if(bRet)
		return nBytesReturn;
	else
		return -1;
}

#endif // __DRIVER_H__