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dvmhost/src/common/nxdn/lc/PacketInformation.cpp

158 lines
6.1 KiB

// SPDX-License-Identifier: GPL-2.0-only
/*
* Digital Voice Modem - Common Library
* GPLv2 Open Source. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* Copyright (C) 2022,2024 Bryan Biedenkapp, N2PLL
*
*/
#include "Defines.h"
#include "nxdn/NXDNDefines.h"
#include "nxdn/lc/PacketInformation.h"
#include "Log.h"
using namespace nxdn;
using namespace nxdn::defines;
using namespace nxdn::lc;
#include <cassert>
#include <cstring>
// ---------------------------------------------------------------------------
// Public Class Members
// ---------------------------------------------------------------------------
/* Initializes a new instance of the PacketInformation class. */
PacketInformation::PacketInformation() :
m_delivery(false),
m_selectiveRetry(false),
m_blockCount(0U),
m_padCount(0U),
m_start(true),
m_circular(false),
m_fragmentCount(0U),
m_rspClass(PDUResponseClass::ACK),
m_rspType(1U),
m_rspErrorBlock(0U)
{
/* stub */
}
/* Finalizes a instance of the PacketInformation class. */
PacketInformation::~PacketInformation() = default;
/* Decodes packet information. */
bool PacketInformation::decode(const uint8_t messageType, const uint8_t* data)
{
assert(data != nullptr);
switch (messageType)
{
case MessageType::RTCH_DCALL_HDR:
m_delivery = (data[0U] & 0x80U) == 0x80U; // Delivery
m_selectiveRetry = (data[0U] & 0x20U) == 0x20U; // Selective Retry
m_blockCount = (data[0U] & 0x0FU); // Block Count
m_padCount = (data[1U] >> 3) & 0x1FU; // Pad Count
m_start = (data[1U] & 0x08U) == 0x08U; // Start/First Fragment
m_circular = (data[1U] & 0x04U) == 0x04U; // Circular Fragment Count
m_fragmentCount = ((data[1U] & 0x01U) << 8) + data[2U]; // Fragment Count
break;
case MessageType::RTCH_DCALL_ACK:
m_rspClass = (data[0U] >> 4) & 0x03U; // Response Class
m_rspType = (data[0U] >> 1) & 0x07U; // Response Type
m_fragmentCount = ((data[0U] & 0x01U) << 8) + data[1U]; // Fragment Count
break;
case MessageType::RTCH_SDCALL_REQ_HDR:
m_delivery = (data[0U] & 0x80U) == 0x80U; // Delivery
m_selectiveRetry = (data[0U] & 0x20U) == 0x20U; // Selective Retry
m_blockCount = (data[0U] & 0x0FU); // Block Count
m_padCount = (data[1U] >> 3) & 0x1FU; // Pad Count
m_start = (data[1U] & 0x08U) == 0x08U; // Start/First Fragment
m_circular = (data[1U] & 0x04U) == 0x04U; // Circular Fragment Count
break;
default:
LogError(LOG_NXDN, "PacketInformation::decode(), unknown LC value, messageType = $%02X", messageType);
return false;
}
return true;
}
/* Encodes packet information. */
void PacketInformation::encode(const uint8_t messageType, uint8_t* data)
{
assert(data != nullptr);
switch (messageType)
{
case MessageType::RTCH_DCALL_HDR:
{
::memset(data, 0x00U, PCKT_INFO_LENGTH_BYTES);
data[0U] = (m_delivery ? 0x80U : 0x00U) + // Delivery
(m_selectiveRetry ? 0x20U : 0x00U) + // Selective Retry
m_blockCount; // Block Count
data[1U] = (m_padCount << 3) + // Pad Count
(m_start ? 0x08U : 0x00U) + // Start/First Fragment
(m_circular ? 0x04U : 0x00U); // Circular Fragment Count
bool highFragCount = (m_fragmentCount & 0x100U) == 0x100U;
data[1U] += (highFragCount ? 0x01U : 0x00U); // Fragment Count - bit 8
data[2U] = m_fragmentCount & 0xFFU; // Fragment Count - bit 0 - 7
}
break;
case MessageType::RTCH_DCALL_ACK:
{
data[0U] = ((m_rspClass & 0x03U) << 4) | // Response Class
((m_rspType & 0x07U) << 1); // Response Type
bool highFragCount = (m_fragmentCount & 0x100U) == 0x100U;
data[0U] += (highFragCount ? 0x01U : 0x00U); // Fragment Count - bit 8
data[1U] = m_fragmentCount & 0xFFU; // Fragment Count - bit 0 - 7
}
break;
case MessageType::RTCH_SDCALL_REQ_HDR:
::memset(data, 0x00U, PCKT_INFO_LENGTH_BYTES);
data[0U] = (m_delivery ? 0x80U : 0x00U) + // Delivery
(m_selectiveRetry ? 0x20U : 0x00U) + // Selective Retry
m_blockCount; // Block Count
data[1U] = (m_padCount << 3) + // Pad Count
(m_start ? 0x08U : 0x00U) + // Start/First Fragment
(m_circular ? 0x04U : 0x00U); // Circular Fragment Count
break;
default:
LogError(LOG_NXDN, "PacketInformation::encode(), unknown LC value, messageType = $%02X", messageType);
break;
}
}
/* Helper to reset data values to defaults. */
void PacketInformation::reset()
{
m_delivery = false;
m_selectiveRetry = false;
m_blockCount = 0U;
m_padCount = 0U;
m_start = true;
m_circular = false;
m_fragmentCount = 0U;
m_rspClass = PDUResponseClass::ACK;
m_rspType = 0U;
m_rspErrorBlock = 0U;
}

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