DMRCSBK.cpp

/*
 *   Copyright (C) 2015,2016,2020,2021,2022,2023,2025 by Jonathan Naylor G4KLX
 *   Copyright (C) 2019 by Patrick Maier DK5MP
 *   Copyright (C) 2026 by Adrian Musceac YO8RZZ
 *
 *   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 "DMRCSBK.h"
#include "BPTC19696.h"
#include "Utils.h"
#include "CRC.h"
#include "Log.h"

#if defined(USE_DMR)

#include <cstdio>
#include <cassert>

CDMRCSBK::CDMRCSBK() :
m_data(nullptr),
m_CSBKO(CSBKO::NONE),
m_FID(0x00U),
m_GI(false),
m_bsId(0U),
m_srcId(0U),
m_dstId(0U),
m_dataContent(false),
m_CBF(0U),
m_OVCM(false),
m_dataType(DT_CSBK)
{
	m_data = new unsigned char[12U];
}

CDMRCSBK::~CDMRCSBK()
{
	delete[] m_data;
}

void CDMRCSBK::setCSBKData(unsigned char* bytes)
{
	assert(bytes != nullptr);

	::memcpy(m_data, bytes, 10U);
}

bool CDMRCSBK::put(const unsigned char* bytes)
{
	assert(bytes != nullptr);

	CBPTC19696 bptc;
	bptc.decode(bytes, m_data);

	switch (m_dataType) {
	case DT_CSBK:
		m_data[10U] ^= CSBK_CRC_MASK[0U];
		m_data[11U] ^= CSBK_CRC_MASK[1U];
		break;

	case DT_MBC_HEADER:
		m_data[10U] ^= MBC_CRC_MASK[0U];
		m_data[11U] ^= MBC_CRC_MASK[1U];
		break;

	case DT_MBC_CONTINUATION:
		break;

	default:
		LogError("Unknown DMR CSBK data type: 0x%02X", m_dataType);
		return false;
	}

	bool valid = CCRC::checkCCITT162(m_data, 12U);
	if (!valid)
		return false;

	// Restore the checksum
	switch (m_dataType) {
	case DT_CSBK:
		m_data[10U] ^= CSBK_CRC_MASK[0U];
		m_data[11U] ^= CSBK_CRC_MASK[1U];
		break;

	case DT_MBC_HEADER:
		m_data[10U] ^= MBC_CRC_MASK[0U];
		m_data[11U] ^= MBC_CRC_MASK[1U];
		break;

	case DT_MBC_CONTINUATION:
		break;

	default:
		LogError("Unknown DMR CSBK data type: 0x%02X", m_dataType);
		return false;
	}

	m_CSBKO = CSBKO(m_data[0U] & 0x3FU);
	m_FID   = m_data[1U];

	switch (m_CSBKO) {
	case CSBKO::BSDWNACT:
		m_GI    = false;
		m_bsId  = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U]; 
		m_dataContent = false;
		m_CBF   = 0U;
		CUtils::dump(1U, "Downlink Activate CSBK", m_data, 12U);
		break;

	case CSBKO::UUVREQ:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		m_OVCM  = (m_data[2U] & 0x04U) == 0x04U;
		CUtils::dump(1U, "Unit to Unit Service Request CSBK", m_data, 12U);
		break;

	case CSBKO::UUANSRSP:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		m_OVCM  = (m_data[2U] & 0x04U) == 0x04U;
		CUtils::dump(1U, "Unit to Unit Service Answer Response CSBK", m_data, 12U);
		break;

	case CSBKO::PRECCSBK:
		m_GI    = (m_data[2U] & 0x40U) == 0x40U;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = (m_data[2U] & 0x80U) == 0x80U;
		m_CBF   = m_data[3U];
		CUtils::dump(1U, "Preamble CSBK", m_data, 12U);
		break;

	case CSBKO::NACKRSP:
		m_GI    = false;
		m_srcId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_dstId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		CUtils::dump(1U, "Negative Acknowledge Response CSBK", m_data, 12U);
		break;

	case CSBKO::CALL_ALERT:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		CUtils::dump(1U, "Call Alert CSBK", m_data, 12U);
		break;

	case CSBKO::CALL_ALERT_ACK:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		CUtils::dump(1U, "Call Alert Ack CSBK", m_data, 12U);
		break;

	case CSBKO::RADIO_CHECK:
		m_GI    = false;
		if (m_data[3U] == 0x80) {
			m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
			m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
			CUtils::dump(1U, "Radio Check Req CSBK", m_data, 12U);
		} else {
			m_srcId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
			m_dstId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
			CUtils::dump(1U, "Radio Check Ack CSBK", m_data, 12U);
		}
		m_dataContent = false;
		m_CBF   = 0U;
		break;

	case CSBKO::ACKU:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = m_data[3U];
		CUtils::dump(1U, "ACKU CSBK", m_data, 12U);
		break;

	case CSBKO::MAINT:
		m_GI    = false;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = m_data[3U];
		CUtils::dump(1U, "MAINT CSBK", m_data, 12U);
		break;

	case CSBKO::CALL_EMERGENCY:
		m_GI    = true;
		m_dstId = m_data[4U] << 16 | m_data[5U] << 8 | m_data[6U];
		m_srcId = m_data[7U] << 16 | m_data[8U] << 8 | m_data[9U];
		m_dataContent = false;
		m_CBF   = 0U;
		CUtils::dump(1U, "Call Emergency CSBK", m_data, 12U);
		break;

	default:
		m_GI    = false;
		m_srcId = 0U;
		m_dstId = 0U;
		m_dataContent = false;
		m_CBF = 0U;
		CUtils::dump("Unhandled CSBK type", m_data, 12U);
		return true;
	}

	return true;
}

void CDMRCSBK::get(unsigned char* bytes) const
{
	assert(bytes != nullptr);

	switch (m_dataType) {
	case DT_CSBK:
		m_data[10U] ^= CSBK_CRC_MASK[0U];
		m_data[11U] ^= CSBK_CRC_MASK[1U];

		CCRC::addCCITT162(m_data, 12U);

		m_data[10U] ^= CSBK_CRC_MASK[0U];
		m_data[11U] ^= CSBK_CRC_MASK[1U];
		break;

	case DT_MBC_HEADER:
		m_data[10U] ^= MBC_CRC_MASK[0U];
		m_data[11U] ^= MBC_CRC_MASK[1U];

		CCRC::addCCITT162(m_data, 12U);

		m_data[10U] ^= MBC_CRC_MASK[0U];
		m_data[11U] ^= MBC_CRC_MASK[1U];
		break;

	case DT_MBC_CONTINUATION:
		CCRC::addCCITT162(m_data, 12U);
		break;

	default:
		LogError("Unknown DMR CSBK data type: 0x%02X", m_dataType);
		return;
	}

	CBPTC19696 bptc;
	bptc.encode(m_data, bytes);
}

CSBKO CDMRCSBK::getCSBKO() const
{
	return m_CSBKO;
}

unsigned char CDMRCSBK::getFID() const
{
	return m_FID;
}

bool CDMRCSBK::getOVCM() const
{
	return m_OVCM;
}

void CDMRCSBK::setOVCM(bool ovcm)
{
	if ((m_CSBKO == CSBKO::UUVREQ) || (m_CSBKO == CSBKO::UUANSRSP)) {
		m_OVCM = ovcm;

		if (ovcm)
			m_data[2U] |= 0x04U;
		else
			m_data[2U] &= 0xFBU;
	}
}

bool CDMRCSBK::getGI() const
{
	return m_GI;
}

unsigned int CDMRCSBK::getBSId() const
{
	return m_bsId;
}

unsigned int CDMRCSBK::getSrcId() const
{
	return m_srcId;
}

unsigned int CDMRCSBK::getDstId() const
{
	return m_dstId;
}

bool CDMRCSBK::getDataContent() const
{
	return m_dataContent;
}

unsigned char CDMRCSBK::getCBF() const
{
	return m_CBF;
}

void CDMRCSBK::setCBF(unsigned char cbf)
{
	m_CBF = m_data[3U] = cbf;
}

void CDMRCSBK::setDataType(unsigned char dataType)
{
	m_dataType = dataType;
}

unsigned char CDMRCSBK::getDataType() const
{
	return m_dataType;
}

#endif