//
// ICMPv4PacketImpl.h
//
// $Id: //poco/1.3/Net/include/Poco/Net/ICMPv4PacketImpl.h#2 $
//
// Library: Net
// Package: ICMP
// Module:  ICMPv4PacketImpl
//
// Definition of the ICMPv4PacketImpl class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Net_ICMPv4PacketImpl_INCLUDED
#define Net_ICMPv4PacketImpl_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/Net/Socket.h"
#include "Poco/Net/ICMPPacketImpl.h"


namespace Poco {
namespace Net {


class Net_API ICMPv4PacketImpl : public ICMPPacketImpl
	/// This class implements the ICMPv4 packet.
	/// Parts are based on original ICMP code by
	/// Mike Muuss
	/// U. S. Army Ballistic Research Laboratory
 	/// December, 1983
{
public:
	// ICMPv4 header
	struct Header 
	{
		Poco::UInt8 type;          // ICMP packet type
		Poco::UInt8 code;          // Type sub code
		Poco::UInt16 checksum;
		Poco::UInt16 id;
		Poco::UInt16 seq;
	};

	enum MessageType
	{
		ECHO_REPLY,
		ICMP_1,
		ICMP_2,
		DESTINATION_UNREACHABLE,
		SOURCE_QUENCH,
		REDIRECT,
		ICMP_6,
		ICMP_7,
		ECHO_REQUEST,
		ICMP_9,
		ICMP_10,
		TIME_EXCEEDED,
		PARAMETER_PROBLEM,
		TIMESTAMP_REQUEST,
		TIMESTAMP_REPLY,
		INFORMATION_REQUEST,
		INFORMATION_REPLY,
		MESSAGE_TYPE_UNKNOWN,  // non-standard default, must remain last but one
		MESSAGE_TYPE_LENGTH    // length indicator, must remain last
	};

	enum DestinationUnreachableCode
	{
		NET_UNREACHABLE,
		HOST_UNREACHABLE,
		PROTOCOL_UNREACHABLE,
		PORT_UNREACHABLE,
		FRAGMENTATION_NEEDED_AND_DF_SET,
		SOURCE_ROUTE_FAILED,
		DESTINATION_UNREACHABLE_UNKNOWN, // non-standard default, must remain last but one
		DESTINATION_UNREACHABLE_LENGTH   // length indicator, must remain last
	};

	enum RedirectMessageCode
	{
		REDIRECT_NETWORK,
		REDIRECT_HOST,
		REDIRECT_SERVICE_NETWORK,
		REDIRECT_SERVICE_HOST,
		REDIRECT_MESSAGE_UNKNOWN, // non-standard default, must remain last but one
		REDIRECT_MESSAGE_LENGTH   // length indicator, must remain last
	};

	enum TimeExceededCode
	{
		TIME_TO_LIVE,
		FRAGMENT_REASSEMBLY,
		TIME_EXCEEDED_UNKNOWN, // non-standard default, must remain last but one
		TIME_EXCEEDED_LENGTH   // length indicator, must remain last
	};

	enum ParameterProblemCode
	{
		POINTER_INDICATES_THE_ERROR,
		PARAMETER_PROBLEM_UNKNOWN, // non-standard default, must remain last but one
		PARAMETER_PROBLEM_LENGTH   // length indicator, must remain last
	};

	ICMPv4PacketImpl(int dataSize = 48);
		/// Constructor. Creates an ICMPv4PacketImpl.

	~ICMPv4PacketImpl();
		/// Destructor.

	int packetSize() const;
		/// Returns the total length of packet (header + data);

	struct timeval time(Poco::UInt8* buffer = 0, int length = 0) const;
		/// Returns current epoch time if either buffer or length are equal to zero.
		/// Otherwise, it extracts the time value from the supplied buffer.
		/// 
		/// Buffer includes IP header, ICMP header and data.

	bool validReplyID(Poco::UInt8* buffer, int length) const;
		/// Returns true if the extracted id is recognized 
		/// (i.e. equals the process id).
		///	
		/// Buffer includes IP header, ICMP header and data.

	virtual std::string errorDescription(Poco::UInt8* buffer, int length);
		/// Returns error description string.
		/// If supplied buffer contains ICMPv4 echo reply packet, an
		/// empty string is returned indicating the absence of error.
		///	
		/// Buffer includes IP header, ICMP header and data.

	virtual std::string typeDescription(int typeId);
		/// Returns the description of the packet type.

	static const Poco::UInt16 MAX_PACKET_SIZE;
	static const std::string MESSAGE_TYPE[MESSAGE_TYPE_LENGTH];
	static const Poco::UInt8 DESTINATION_UNREACHABLE_TYPE; // 3
	static const Poco::UInt8 SOURCE_QUENCH_TYPE;           // 4
	static const Poco::UInt8 REDIRECT_MESSAGE_TYPE;        // 5
	static const Poco::UInt8 TIME_EXCEEDED_TYPE;           // 11
	static const Poco::UInt8 PARAMETER_PROBLEM_TYPE;       // 12

private:
	void initPacket();
	Header* header(Poco::UInt8* buffer, int length) const;
	Poco::UInt8* data(Poco::UInt8* buffer, int length) const;

	static const std::string DESTINATION_UNREACHABLE_CODE[DESTINATION_UNREACHABLE_LENGTH];
	static const std::string REDIRECT_MESSAGE_CODE[REDIRECT_MESSAGE_LENGTH];
	static const std::string TIME_EXCEEDED_CODE[TIME_EXCEEDED_LENGTH];
	static const std::string PARAMETER_PROBLEM_CODE[PARAMETER_PROBLEM_LENGTH];
  
	Poco::UInt16 _seq;
};


} } // namespace Poco::Net


#endif // Net_ICMPv4PacketImpl_INCLUDED