// Icmp.h : header file
//
//////////////////////////////////////////////////////////////////////////////////
//																				//
//								The CIcmp class									//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//																				//
//			1998. EarthWalk Designs Software, by Jay Wheeler.					//
//			All inquiries and/or comments to Jay@EarthWalkDesigns.com			//
//			Latest version can be downloaded from:								//
//																				//
//				http://www.earthwalkdesigns.com									//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//																				//
//			Designed using Microsoft VisualC++ 4.2 and MFC						//
//			Tested on WindowsNT 4.0 Workstation and Server						//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//																				//
//			This software is released into the public domain as is and			//
//			without warranty.													//
//																				//
//			Use it in good health, and please let me know if it was useful.		//
//			If you make improvements or fixed problems, please drop me an		//
//			e-mail describing your changes.  I will try to incorporate			//
//			them into this package so that others may benefit from your			//
//			improvements.														//
//																				//
//			Enjoy!																//
//																				// 
//////////////////////////////////////////////////////////////////////////////////
//																				//
//					Icmp Class - Derived from CSocket class						//
//																				//
//		Provides the following class methods for WindowsNT 4.0 systems			//
//		utilizing the WindowsNT Winsock 2 interface to the Internet.			//
//																				//
//////////////////////////////////////////////////////////////////////////////////
//																				//
//		OpenNewSocket															//
//			When called with no arguements, 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.							//
//																				//
//		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.							//
//																				//
//		Connect																	//
//			When called with 2 arguements, 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.							//
//																				//
//		Connect																	//
//			When called with 5 arguements, connects an Icmp object to a socket	//
//			of specified family, type and 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.							//
//																				//
//		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.							//
//																				//
//		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.							//
//																				//
//		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.							//
//																				//
//		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.								//
//																				//
//			The Icmp variable icmpPingSentAt is set to the time value at the	//
//			time the ping message is sent.										//
//																				//
//			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.							//
//																				//
//		IcmpChecksum															//
//			Computes the icmp checksum of the Len data in the buffer referenced	//
//			by lpBuf.															//
//																				//
//			Returns an unsigned integer value of the computed checksum.			//
//																				//
//		GetIPAddress															//
//			Returns the value of the IP address of the host pointed by			//
//			iHostName as an unsigned long in network byte order, as described	//
//			in inet_aton														//
//																				//
//			Sets iHostName to the value of the host name returned in			//
//			icmpHostEnt.														//
//																				//
//			Requires the message number to send to the window, and the events	//
//			to notify on.														//
//																				//
//			Sets Icmp variable icmpSockAddr fields appropriately, leaving the	//
//			IP address in icmpSockAddr.sin_addr, and the type of address in		//
//			icmpSockAddr.sin_family.  Also sets icmpHostEnt fields appropriately//
//																				//
//			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.							//
//																				//
//		Receive																	//
//																				//
//			Reads the socket associated with the Icmp object and returns the	//
//			number of bytes read, or SOCKET_ERROR, if an error occurs.			//
//																				//
//			Requires the address of the buffer to store the incoming message	//
//			and an integer buffer size.  The buffer must be large enough to		//
//			contain the incoming message.  In the case of an ICMP ping echo		//
//			response, the size would be the size of the outgoing message plus	//
//			the size of an ICMP header plus the size of an IP header.			//
//																				//
//			Sets icmpPingReceivedAt to the time the receive command is issued,	//
//			icmpRoundTripTime to the difference between icmpPingSentAt and		//
//			icmpPingReceivedAt, icmpCurSeq to the incoming sequence number		//
//			and icmpCurId to the incoming id field.								//