ircDDBGateway/Common/G2ProtocolHandler.cpp

/*
 *   Copyright (C) 2010,2011,2013 by Jonathan Naylor G4KLX
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "G2ProtocolHandler.h"

#include "DStarDefines.h"
#include "Utils.h"

// #define	DUMP_TX

const unsigned int BUFFER_LENGTH = 255U;

CG2ProtocolHandler::CG2ProtocolHandler(unsigned int port, const wxString& addr) :
m_socket(addr, port),
m_type(GT_NONE),
m_buffer(NULL),
m_length(0U)
{
	m_buffer = new unsigned char[BUFFER_LENGTH];
}

CG2ProtocolHandler::~CG2ProtocolHandler()
{
	delete[] m_buffer;
}

bool CG2ProtocolHandler::open()
{
	return m_socket.open();
}

bool CG2ProtocolHandler::writeHeader(const CHeaderData& header)
{
	unsigned char buffer[60U];
	unsigned int length = header.getG2Data(buffer, 60U, true);

#if defined(DUMP_TX)
	CUtils::dump(wxT("Sending Header"), buffer, length);
#endif

	for (unsigned int i = 0U; i < 5U; i++) {
		bool res = m_socket.write(buffer, length, header.getYourAddress(), header.getYourPort());
		if (!res)
			return false;
	}

	return true;
}

bool CG2ProtocolHandler::writeAMBE(const CAMBEData& data)
{
	unsigned char buffer[40U];
	unsigned int length = data.getG2Data(buffer, 40U);

#if defined(DUMP_TX)
	CUtils::dump(wxT("Sending Data"), buffer, length);
#endif

	return m_socket.write(buffer, length, data.getYourAddress(), data.getYourPort());
}

G2_TYPE CG2ProtocolHandler::read(in_addr& remoteAddress, unsigned int& remotePort)
{
	bool res = true;

	// Loop until we have no more data from the socket or we have data for the higher layers
	while (res)
		res = readPackets(remoteAddress, remotePort);

	return m_type;
}

bool CG2ProtocolHandler::readPackets(in_addr& remoteAddress, unsigned int& remotePort)
{
	m_type = GT_NONE;
	remotePort = 0;

	// No more data?
	int length = m_socket.read(m_buffer, BUFFER_LENGTH, remoteAddress, remotePort);
	if (length <= 0)
		return false;

	m_length = length;

	if (m_buffer[0] != 'D' || m_buffer[1] != 'S' || m_buffer[2] != 'V' || m_buffer[3] != 'T') {
		if(length == 1 && m_buffer[0] == 0)
			return false;//we have been udp punched

		return true;
	} else {
		// Header or data packet type?
		if ((m_buffer[14] & 0x80) == 0x80)
			m_type = GT_HEADER;
		else
			m_type = GT_AMBE;

		return false;
	}
}

CHeaderData* CG2ProtocolHandler::readHeader(in_addr remoteAddress, unsigned int remotePort)
{
	if (m_type != GT_HEADER)
		return NULL;

	CHeaderData* header = new CHeaderData;

	// G2 checksums are unreliable
	bool res = header->setG2Data(m_buffer, m_length, false, remoteAddress, remotePort);
	if (!res) {
		delete header;
		return NULL;
	}

	return header;
}

CAMBEData* CG2ProtocolHandler::readAMBE(in_addr remoteAddress, unsigned int remotePort)
{
	if (m_type != GT_AMBE)
		return NULL;

	CAMBEData* data = new CAMBEData;

	bool res = data->setG2Data(m_buffer, m_length, remoteAddress, remotePort
);
	if (!res) {
		delete data;
		return NULL;
	}

	return data;
}

void CG2ProtocolHandler::traverseNat(const wxString& address)
{
	unsigned char buffer[1];
	::memset(buffer, 0, 1);
	
	in_addr addr = CUDPReaderWriter::lookup(address);

	//wxLogError(wxT("Punching hole to %s"), address.mb_str());

	m_socket.write(buffer, 1, addr, G2_DV_PORT);
}

void CG2ProtocolHandler::close()
{
	m_socket.close();
}