//
// ICMPSocketImpl.cpp
//
// $Id: //poco/1.4/Net/src/ICMPSocketImpl.cpp#1 $
//
// Library: Net
// Package: ICMP
// Module:  ICMPSocketImpl
//
// 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.
//


#include "Poco/Net/ICMPSocketImpl.h"
#include "Poco/Net/NetException.h"
#include "Poco/Timespan.h"
#include "Poco/Timestamp.h"
#include "Poco/Exception.h"


using Poco::TimeoutException;
using Poco::Timespan;
using Poco::Exception;


namespace Poco {
namespace Net {


ICMPSocketImpl::ICMPSocketImpl(IPAddress::Family family, int dataSize, int ttl, int timeout):
	RawSocketImpl(family, IPPROTO_ICMP),
	_icmpPacket(family, dataSize),
	_timeout(timeout)
{
	setOption(IPPROTO_IP, IP_TTL, ttl);
	setReceiveTimeout(Timespan(timeout));
}


ICMPSocketImpl::~ICMPSocketImpl()
{
}


int ICMPSocketImpl::sendTo(const void*, int, const SocketAddress& address, int flags)
{
	int n = SocketImpl::sendTo(_icmpPacket.packet(), _icmpPacket.packetSize(), address, flags);
	return n;
}


int ICMPSocketImpl::receiveFrom(void*, int, SocketAddress& address, int flags)
{
	int maxPacketSize = _icmpPacket.maxPacketSize();
	unsigned char* buffer = new unsigned char[maxPacketSize];

	try
	{
		Poco::Timestamp ts;
		do
		{
			if (ts.isElapsed(_timeout)) 
			{
				// This guards against a possible DoS attack, where sending
				// fake ping responses will cause an endless loop.
				throw TimeoutException();
			}
			SocketImpl::receiveFrom(buffer, maxPacketSize, address, flags);
		}
		while (!_icmpPacket.validReplyID(buffer, maxPacketSize));
	}
	catch (TimeoutException&)
	{
		delete [] buffer;			
		throw;
	}
	catch (Exception&)
	{
		std::string err = _icmpPacket.errorDescription(buffer, maxPacketSize);
		delete [] buffer;
		if (!err.empty()) 
			throw ICMPException(err);
		else 
			throw;
	}

	struct timeval then = _icmpPacket.time(buffer, maxPacketSize);
	struct timeval now  = _icmpPacket.time();

	int elapsed	= (((now.tv_sec * 1000000) + now.tv_usec) - ((then.tv_sec * 1000000) + then.tv_usec))/1000;

	delete[] buffer;
	return elapsed;
}


} } // namespace Poco::Net