icmp.cpp

Visual+C++网络通信协议分析

	icmpCurSeq = copy.icmpCurSeq;
	icmpCurId = copy.icmpCurId;
	icmpRcvLen = copy.icmpRcvLen;
}

/////////////////////////////////////////////////////////////////////////////
// CIcmp member functions

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		OpenNewSocket															//
//			Opens a SOCKET connection to a RAW socket with ICMP protocol.		//
//																				//
//			Requires a handle to a message processor which will process the		//
//			socket events, the message number to process, and a mask giving		//
//			the events to process.												//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns TRUE if successful, else FALSE.				//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//打开一个SOCKET连接使用ICMP协议，需要一个句柄去处理socket事件，
BOOL CIcmp::OpenNewSocket(HWND hWnd, unsigned int NotificationMessage, long NotifyEvents)
{
	//调用另外一个多态函数
	return OpenNewSocket (hWnd,
						  NotificationMessage,
						  NotifyEvents,
						  AF_INET,
						  SOCK_RAW,
						  IPPROTO_ICMP);
}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		OpenNewSocket															//
//			Opens a SOCKET connection to a socket of specified family, type		//
//			and protocol														//
//																				//
//			Requires a handle to a message processor which will process the		//
//			socket events, the message number to process, and a mask giving		//
//			the events to process.												//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns TRUE if successful, else FALSE.				//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//打开一个连接，确定具体的family，类型和协议
BOOL CIcmp::OpenNewSocket(HWND hWnd, unsigned int NotificationMessage, long NotifyEvents, int AFamily, int AType, int AProtocol)
{

	if (icmpSocket != INVALID_SOCKET)
		CloseIcmpSocket();

	if (!Connect(&icmpPingTimer,
			    &icmpPingTimer,
			    AFamily,
			    AType,
			    AProtocol))
		return FALSE;
	//
	//		Set asynchronous notification and start message interrupt processor
	//

	if (SetAsynchNotification(hWnd,
		  					  NotificationMessage,
							  NotifyEvents) == SOCKET_ERROR)
	{
		return FALSE;
	}

	return TRUE;
}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		Connect																	//
//			Connects an Icmp object to a RAW socket with ICMP protocol.			//
//																				//
//			Requires 2 integer values specifying the receive and transmit		//
//			timeouts															//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns TRUE if successful, else FALSE.				//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//连接一个Icmp对象需要两个整数变量来保存接收和发送超时时间
BOOL CIcmp::Connect(int ReceiveTimeout, int SendTimeout)
{

	return Connect(&ReceiveTimeout, 
				   &SendTimeout, 
				   AF_INET, 
				   SOCK_RAW, 
				   IPPROTO_ICMP);

}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		Connect																	//
//			Connects an Icmp object to a socket of specified family, type		//
//			and protocol														//
//																				//
//			Requires 2 integer values specifying the receive and transmit		//
//			timeouts, the ICMP family, ICMP socket type, and ICMP protocol.		//															//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns TRUE if successful, else FALSE.				//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////

BOOL CIcmp::Connect(LPINT ReceiveTimeout, LPINT SendTimeout, int AFamily, int AType, int AProtocol)
{

	int			Result;
	
	icmpSocket = NULL;

	icmpSocket = socket (AFamily,
						 AType,
						 AProtocol);

	if (icmpSocket == INVALID_SOCKET)
	{
		icmpSocketError = WSAGetLastError();
		icmpSocketErrorMod = 1;
		return FALSE;
	}
	
	//
	//		设定接收超时时间
	//

	Result = setsockopt (icmpSocket, 
					     SOL_SOCKET, 
						 SO_RCVTIMEO, 
						 (char *)ReceiveTimeout, 
						 sizeof(int));
	if (Result == SOCKET_ERROR)
	{
		icmpSocketError = WSAGetLastError();
		icmpSocketErrorMod = 2;
		closesocket (icmpSocket);
		icmpSocket = INVALID_SOCKET;
		return FALSE;
	}

	//
	//		设定发送超时时间
	//
	Result = setsockopt (icmpSocket, 
					     SOL_SOCKET, 
						 SO_SNDTIMEO, 
						 (char *)SendTimeout, 
						 sizeof(int));
	if (Result == SOCKET_ERROR)
	{
		icmpSocketError = WSAGetLastError();
		icmpSocketErrorMod = 3;
		closesocket (icmpSocket);
		icmpSocket = INVALID_SOCKET;
		return FALSE;
	}

	icmpCurSeq = 0;
	icmpCurId = (USHORT)GetCurrentProcessId();
	icmpHops = 0;

	return TRUE;

}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		CloseIcmpSocket																	//
//			Closes a socket associated with an Icmp object.						//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns the integer result of the operation.			//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////
int CIcmp::CloseIcmpSocket(void)
{

	if (icmpSocket == INVALID_SOCKET)
		return 0;
	int Result = closesocket(icmpSocket);
	if (Result == SOCKET_ERROR)
	{
		icmpSocketError = WSAGetLastError();
		icmpSocketErrorMod = 1;

		icmpSocket = INVALID_SOCKET;
	}
	return Result;

}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		SetAsynchNotification													//
//			Sets the window (process) to notify when a network event on the		//
//			socket associated with the Icmp object occurs.						//
//																				//
//			Requires the message number to send to the window, and the events	//
//			to notify on.														//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns the integer result of the operation.			//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////

//消息处理函数，当有网络事件产生的时候
int CIcmp::SetAsynchNotification(HWND hWnd, unsigned int Message, long Events)
{
	//异步选择事件的I/O方法
	int Result = WSAAsyncSelect (icmpSocket,
			 				     hWnd, 
								 Message, 
								 Events);
	if (Result == SOCKET_ERROR)
	{
		icmpSocketError = WSAGetLastError();
		icmpSocketErrorMod = 1;

		icmpSocket = INVALID_SOCKET;
	}
	return Result;
}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		SetTTL																	//
//			Set the TTL option on the socket associated with an Icmp object.	//
//			A TTL value of non-zero specifies the number of hops to query		//
//			before a response is returned.  By incrementing the TTL from 1 to	//
//			(number of hops to final destination), a TraceRoute function		//
//			can be performed.													//
//																				//
//			Sets icmpSocketError and icmpSocketErrorMod to indicate the type	//
//			of error, and returns the integer result of the operation.			//
//																				//
//			icmpSocketError and icmpSocketErrorMod are preserved until the next	//
//			operation on this Icmp object is performed.							//
//																				//
//////////////////////////////////////////////////////////////////////////////////

//设定TTL
int CIcmp::SetTTL(int TTL)
{

	int	Result;

	Result = setsockopt (icmpSocket, IPPROTO_IP, IP_TTL, (LPSTR)&TTL, sizeof(int));

	if (Result == SOCKET_ERROR)
	{
		icmpSocketErrorMod = 1;
		icmpSocketError = WSAGetLastError();
	}
	return Result;

}

//////////////////////////////////////////////////////////////////////////////////
//																				//
//		Ping																	//
//			Sends an ICMP ping message to the host indicated in the Icmp		//
//			variable icmpSockAddr.  The Icmp variables icmpCurSeq and			//
//			icmpCurId are sent in the buffer referenced by pIcmpBuffer.  The	//
//			referenced buffer must be large	enough to hold DataLen bytes plus	//
//			the size of the ICMP message header.								//