// SPDX-License-Identifier: GPL-2.0-only
/*
 * Digital Voice Modem - Modem Host Software
 * GPLv2 Open Source. Use is subject to license terms.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 *  Copyright (C) 2016,2017,2018 Jonathan Naylor, G4KLX
 *  Copyright (C) 2017-2025 Bryan Biedenkapp, N2PLL
 *
 */
#include "Defines.h"
#include "common/p25/P25Defines.h"
#include "common/p25/acl/AccessControl.h"
#include "common/p25/data/ConventionalRegistration.h"
#include "common/p25/lc/tdulc/TDULCFactory.h"
#include "common/p25/sndcp/SNDCPFactory.h"
#include "common/p25/P25Utils.h"
#include "common/p25/Sync.h"
#include "common/edac/CRC.h"
#include "common/Log.h"
#include "common/Utils.h"
#include "p25/packet/Data.h"
#include "ActivityLog.h"

using namespace p25;
using namespace p25::defines;
using namespace p25::data;
using namespace p25::sndcp;
using namespace p25::packet;

#include <cassert>
#include <cstring>

// ---------------------------------------------------------------------------
//  Constants
// ---------------------------------------------------------------------------

const uint8_t MAX_PDU_RETRY_CNT = 2U;
const uint32_t CONV_REG_WAIT_TIMEOUT = 750U; // ms
const uint32_t SNDCP_READY_TIMEOUT = 10U;
const uint32_t SNDCP_STANDBY_TIMEOUT = 60U;

// ---------------------------------------------------------------------------
//  Public Class Members
// ---------------------------------------------------------------------------

/* Resets the data states for the RF interface. */

void Data::resetRF()
{
    m_rfPDUCount = 0U;
    m_rfPDUBits = 0U;
}

/* Process a data frame from the RF interface. */

bool Data::process(uint8_t* data, uint32_t len)
{
    assert(data != nullptr);

    // decode the NID
    bool valid = m_p25->m_nid.decode(data + 2U);

    if (m_p25->m_rfState == RS_RF_LISTENING && !valid)
        return false;

    if (m_prevRfState != RS_RF_DATA) {
        m_prevRfState = m_p25->m_rfState;
    }

    uint8_t duid = m_p25->m_nid.getDUID();

    // are we interrupting a running CC?
    if (m_p25->m_ccRunning) {
        m_p25->m_ccHalted = true;
    }

    // handle individual DUIDs
    if (duid == DUID::PDU) {
        m_inbound = true;

        if (m_p25->m_rfState != RS_RF_DATA) {
            m_rfPDUCount = 0U;
            m_rfPDUBits = 0U;

            ::memset(m_rfPDU, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);

            m_p25->m_rfState = RS_RF_DATA;

            ::memset(m_rfPduUserData, 0x00U, P25_MAX_PDU_BLOCKS * P25_PDU_CONFIRMED_LENGTH_BYTES + 2U);
            m_rfPduUserDataLength = 0U;
        }

        //Utils::dump(1U, "P25, Data::process(), Raw PDU ISP", data, len);

        uint32_t start = m_rfPDUCount * P25_PDU_FRAME_LENGTH_BITS;

        uint8_t buffer[P25_PDU_FRAME_LENGTH_BYTES];
        ::memset(buffer, 0x00U, P25_PDU_FRAME_LENGTH_BYTES);

        uint32_t bits = P25Utils::decode(data + 2U, buffer, start, start + P25_PDU_FRAME_LENGTH_BITS);
        m_rfPDUBits += Utils::getBits(buffer, m_rfPDU, 0U, bits);

        if (m_rfPDUCount == 0U) {
            ::memset(buffer, 0x00U, P25_PDU_FEC_LENGTH_BYTES);
            Utils::getBitRange(m_rfPDU, buffer, P25_PREAMBLE_LENGTH_BITS, P25_PDU_FEC_LENGTH_BITS);

            bool ret = m_rfAssembler->disassemble(buffer, P25_PDU_FEC_LENGTH_BYTES, true);
            if (!ret) {
                m_rfPDUCount = 0U;
                m_rfPDUBits = 0U;
                m_p25->m_rfState = m_prevRfState;
                return false;
            }

            // if we're a dedicated CC or in control only mode, we only want to handle AMBTs. Otherwise return
            if ((m_p25->m_dedicatedControl || m_p25->m_controlOnly) && m_rfAssembler->dataHeader.getFormat() != PDUFormatType::AMBT) {
                if (m_debug) {
                    LogDebug(LOG_RF, "CC only mode, ignoring non-AMBT PDU from RF");
                }
                
                m_p25->m_ccHalted = false;
                
                m_rfPDUCount = 0U;
                m_rfPDUBits = 0U;
                m_p25->m_rfState = m_prevRfState;
                return false;
            }

            // did we receive a response header?
            if (m_rfAssembler->dataHeader.getFormat() == PDUFormatType::RSP) {
                // clear inbound before emitting outbound OSP bursts (ACK/NACK, retries) below
                m_inbound = false;
                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, fmt = $%02X, rspClass = $%02X, rspType = $%02X, rspStatus = $%02X, llId = %u, srcLlId = %u",
                        m_rfAssembler->dataHeader.getFormat(), m_rfAssembler->dataHeader.getResponseClass(), m_rfAssembler->dataHeader.getResponseType(), m_rfAssembler->dataHeader.getResponseStatus(),
                        m_rfAssembler->dataHeader.getLLId(), m_rfAssembler->dataHeader.getSrcLLId());

                if (m_rfAssembler->dataHeader.getResponseClass() == PDUAckClass::ACK && m_rfAssembler->dataHeader.getResponseType() == PDUAckType::ACK) {
                    LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP ACK, llId = %u, all blocks received OK, n = %u",
                        m_rfAssembler->dataHeader.getLLId(), m_rfAssembler->dataHeader.getResponseStatus());
                    m_retryPDUState.erase(m_rfAssembler->dataHeader.getLLId());
                } else {
                    if (m_rfAssembler->dataHeader.getResponseClass() == PDUAckClass::NACK) {
                        switch (m_rfAssembler->dataHeader.getResponseType()) {
                            case PDUAckType::NACK_ILLEGAL:
                                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP NACK, illegal format, llId = %u",
                                    m_rfAssembler->dataHeader.getLLId());
                                break;
                            case PDUAckType::NACK_PACKET_CRC:
                                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP NACK, packet CRC error, llId = %u, n = %u",
                                    m_rfAssembler->dataHeader.getLLId(), m_rfAssembler->dataHeader.getResponseStatus());
                                break;
                            case PDUAckType::NACK_SEQ:
                            case PDUAckType::NACK_OUT_OF_SEQ:
                                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP NACK, packet out of sequence, llId = %u, seqNo = %u",
                                    m_rfAssembler->dataHeader.getLLId(), m_rfAssembler->dataHeader.getResponseStatus());
                                break;
                            case PDUAckType::NACK_UNDELIVERABLE:
                                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP NACK, packet undeliverable, llId = %u, n = %u",
                                    m_rfAssembler->dataHeader.getLLId(), m_rfAssembler->dataHeader.getResponseStatus());
                                break;

                            default:
                                break;
                            }
                    } else if (m_rfAssembler->dataHeader.getResponseClass() == PDUAckClass::ACK_RETRY) {
                        LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP ACK RETRY, llId = %u",
                            m_rfAssembler->dataHeader.getLLId());

                        // really this is supposed to check the bit field in the included response 
                        // and only return those bits -- but we're responding with the entire previous packet...
                        uint32_t retryLlId = m_rfAssembler->dataHeader.getLLId();
                        auto retry = m_retryPDUState.find(retryLlId);
                        if (retry != m_retryPDUState.end() && retry->second.bitLength > 0U && !retry->second.data.empty()) {
                            if (retry->second.retryCount < MAX_PDU_RETRY_CNT) {
                                m_p25->writeRF_Preamble();
                                writeRF_PDU(retry->second.data.data(), retry->second.bitLength, false, true, retryLlId, false);
                                retry->second.retryCount++;
                            }
                            else {
                                m_retryPDUState.erase(retry);

                                LogInfoEx(LOG_RF, P25_PDU_STR ", ISP, response, OSP ACK RETRY, llId = %u, exceeded retries, undeliverable",
                                    m_rfAssembler->dataHeader.getLLId());

                                writeRF_PDU_Ack_Response(PDUAckClass::NACK, PDUAckType::NACK_UNDELIVERABLE, m_rfAssembler->dataHeader.getNs(), m_rfAssembler->dataHeader.getLLId(), (m_rfAssembler->dataHeader.getSrcLLId() > 0U), m_rfAssembler->dataHeader.getSrcLLId());
                            }
                        }
                    }
                }

                // rewrite the response to the network
                writeNetwork(0U, buffer, P25_PDU_FEC_LENGTH_BYTES, true);

                // only repeat the PDU locally if the packet isn't for the FNE
                if (m_repeatPDU && m_rfAssembler->dataHeader.getLLId() != WUID_FNE) {
                    writeRF_PDU_Ack_Response(m_rfAssembler->dataHeader.getResponseClass(), m_rfAssembler->dataHeader.getResponseType(), m_rfAssembler->dataHeader.getResponseStatus(),
                        m_rfAssembler->dataHeader.getLLId(), (m_rfAssembler->dataHeader.getSrcLLId() > 0U), m_rfAssembler->dataHeader.getSrcLLId());
                }

                m_rfPDUCount = 0U;
                m_rfPDUBits = 0U;
                m_rfPduUserDataLength = 0U;
                ::memset(m_rfPDU, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);

                m_p25->m_rfState = RS_RF_LISTENING;
                m_inbound = false;
                return true;
            }

            m_rfPDUCount++;
        }

        if (m_p25->m_rfState == RS_RF_DATA) {
            uint32_t blocksToFollow = m_rfAssembler->dataHeader.getBlocksToFollow();
            uint32_t bitLength = ((blocksToFollow + 1U) * P25_PDU_FEC_LENGTH_BITS) + P25_PREAMBLE_LENGTH_BITS;

            if (m_rfPDUBits >= bitLength) {
                for (uint32_t i = P25_PREAMBLE_LENGTH_BITS + P25_PDU_FEC_LENGTH_BITS; i < bitLength; i += P25_PDU_FEC_LENGTH_BITS) {
                    LogDebugEx(LOG_P25, "Data::process()", "blocksToFollow = %u, bitLength = %u, rfPDUBits = %u, rfPDUCount = %u", blocksToFollow, bitLength, m_rfPDUBits, m_rfPDUCount);
                    ::memset(buffer, 0x00U, P25_PDU_FEC_LENGTH_BYTES);
                    Utils::getBitRange(m_rfPDU, buffer, i, P25_PDU_FEC_LENGTH_BITS);

                    bool ret = m_rfAssembler->disassemble(buffer, P25_PDU_FEC_LENGTH_BYTES);
                    if (!ret) {
                        m_rfPDUCount = 0U;
                        m_rfPDUBits = 0U;
                        m_p25->m_rfState = m_prevRfState;
                        return false;
                    }

                    m_rfPDUCount++;
                }
            } else {
                LogDebugEx(LOG_P25, "Data::process()", "blocksToFollow = %u, bitLength = %u, rfPDUBits = %u, rfPDUCount = %u", blocksToFollow, bitLength, m_rfPDUBits, m_rfPDUCount);
                ::memset(buffer, 0x00U, P25_PDU_FEC_LENGTH_BYTES);
                Utils::getBitRange(m_rfPDU, buffer, P25_PREAMBLE_LENGTH_BITS + P25_PDU_FEC_LENGTH_BITS, P25_PDU_FEC_LENGTH_BITS);

                bool ret = m_rfAssembler->disassemble(buffer, P25_PDU_FEC_LENGTH_BYTES);
                if (!ret) {
                    m_rfPDUCount = 0U;
                    m_rfPDUBits = 0U;
                    m_p25->m_rfState = m_prevRfState;
                    return false;
                }

                m_rfPDUCount++;
            }

            if (m_rfAssembler->getComplete()) {
                // clear inbound before the SAP switch emits outbound OSP bursts (local repeat, reg)
                m_inbound = false;
                m_rfPduUserDataLength = m_rfAssembler->getUserDataLength();
                m_rfAssembler->getUserData(m_rfPduUserData);

                // never expose a partially decoded or CRC-invalid confirmed packet to
                // registration, routing, or the IP side -- a response without a bitmap
                // requests a conservative whole-PDU retry; selective retry can be added
                // later without weakening this integrity boundary
                if (m_rfAssembler->dataHeader.getFormat() == PDUFormatType::CONFIRMED && (m_rfAssembler->getUndecodableBlockCount() > 0U || m_rfAssembler->getPacketCRCFailed())) {
                    const uint8_t responseClass = m_rfAssembler->getUndecodableBlockCount() > 0U ? PDUAckClass::ACK_RETRY : PDUAckClass::NACK;
                    const uint8_t responseType = m_rfAssembler->getUndecodableBlockCount() > 0U ? PDUAckType::ACK : PDUAckType::NACK_PACKET_CRC;

                    writeRF_PDU_Ack_Response(responseClass, responseType,
                        m_rfAssembler->dataHeader.getNs(), m_rfAssembler->dataHeader.getLLId(),
                        m_rfAssembler->getExtendedAddress(), m_rfAssembler->dataHeader.getSrcLLId());

                    m_rfPDUCount = 0U;
                    m_rfPDUBits = 0U;
                    m_rfPduUserDataLength = 0U;
                    ::memset(m_rfPDU, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);
                    m_p25->m_rfState = RS_RF_LISTENING;
                    return true;
                }

                uint8_t sap = (m_rfAssembler->getExtendedAddress()) ? m_rfAssembler->dataHeader.getEXSAP() : m_rfAssembler->dataHeader.getSAP();
                if (m_rfAssembler->getAuxiliaryES())
                    sap = m_rfAssembler->dataHeader.getEXSAP();

                uint32_t srcId = (m_rfAssembler->getExtendedAddress()) ? m_rfAssembler->dataHeader.getSrcLLId() : m_rfAssembler->dataHeader.getLLId();
                uint32_t dstId = m_rfAssembler->dataHeader.getLLId();

                // handle standard P25 service access points
                switch (sap) {
                case PDUSAP::ARP:
                {
                    if (m_rfPduUserDataLength < P25_PDU_ARP_PCKT_LENGTH) {
                        LogWarning(LOG_RF, P25_PDU_STR ", ignoring truncated ARP payload, length = %u",
                            m_rfPduUserDataLength);
                        break;
                    }

                    /* bryanb: quick and dirty ARP logging */
                    uint8_t arpPacket[P25_PDU_ARP_PCKT_LENGTH];
                    ::memset(arpPacket, 0x00U, P25_PDU_ARP_PCKT_LENGTH);
                    ::memcpy(arpPacket, m_rfPduUserData, P25_PDU_ARP_PCKT_LENGTH);

                    uint16_t opcode = GET_UINT16(arpPacket, 6U);
                    uint32_t srcHWAddr = GET_UINT24(arpPacket, 8U);
                    uint32_t srcProtoAddr = GET_UINT32(arpPacket, 11U);
                    //uint32_t tgtHWAddr = GET_UINT24(arpPacket, 15U);
                    uint32_t tgtProtoAddr = GET_UINT32(arpPacket, 18U);

                    if (m_verbose) {
                        if (opcode == P25_PDU_ARP_REQUEST) {
                            LogInfoEx(LOG_RF, P25_PDU_STR ", ARP request, who has %s? tell %s (%u)", __IP_FROM_UINT(tgtProtoAddr).c_str(), __IP_FROM_UINT(srcProtoAddr).c_str(), srcHWAddr);
                        } else if (opcode == P25_PDU_ARP_REPLY) {
                            LogInfoEx(LOG_RF, P25_PDU_STR ", ARP reply, %s is at %u", __IP_FROM_UINT(srcProtoAddr).c_str(), srcHWAddr);
                        }
                    }

                    writeNet_PDU_User(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(), 
                        m_rfPduUserData);
                    writeRF_PDU_Buffered(); // re-generate buffered PDU and send it on
                }
                break;
                case PDUSAP::SNDCP_CTRL_DATA:
                {
                    if (m_rfAssembler->getUndecodableBlockCount() > 0U)
                        break;

                    if (m_verbose) {
                        LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP_CTRL_DATA (SNDCP Control Data), blocksToFollow = %u",
                            m_rfAssembler->dataHeader.getBlocksToFollow());
                    }

                    processSNDCPControl(m_rfPduUserData);
                    writeNet_PDU_User(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(), 
                        m_rfPduUserData);
                }
                break;
                case PDUSAP::CONV_DATA_REG:
                {
                    if (m_rfAssembler->getUndecodableBlockCount() > 0U) {
                        break;
                    }

                    if (m_verbose) {
                        LogInfoEx(LOG_RF, P25_PDU_STR ", CONV_DATA_REG (Conventional Data Registration), blocksToFollow = %u",
                            m_rfAssembler->dataHeader.getBlocksToFollow());
                    }

                    if (processConvDataReg(m_rfPduUserData, m_rfPduUserDataLength)) {
                        writeNet_PDU_User(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(),
                            m_rfPduUserData);
                    }
                }
                break;
                case PDUSAP::UNENC_KMM:
                case PDUSAP::ENC_KMM:
                {
                    if (m_rfAssembler->getUndecodableBlockCount() > 0U)
                        break;

                    if (m_verbose) {
                        LogInfoEx(LOG_RF, P25_PDU_STR ", KMM (Key Management Message), blocksToFollow = %u",
                            m_rfAssembler->dataHeader.getBlocksToFollow());
                    }

                    writeNet_PDU_User(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(), 
                        m_rfPduUserData);
                }
                break;
                case PDUSAP::TRUNK_CTRL:
                {
                    if (m_rfAssembler->getUndecodableBlockCount() > 0U)
                        break;

                    if (m_verbose) {
                        LogInfoEx(LOG_RF, P25_PDU_STR ", TRUNK_CTRL (Alternate MBT Packet), lco = $%02X, blocksToFollow = %u",
                            m_rfAssembler->dataHeader.getAMBTOpcode(), m_rfAssembler->dataHeader.getBlocksToFollow());
                    }

                    m_p25->m_control->processMBT(m_rfAssembler->dataHeader, m_rfAssembler->dataBlocks);
                }
                break;
                default:
                    writeNet_PDU_User(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(), 
                        m_rfPduUserData);

                    // only repeat the PDU locally if the packet isn't for the FNE
                    if (m_repeatPDU && m_rfAssembler->dataHeader.getLLId() != WUID_FNE) {
                        ::ActivityLog("P25", true, "RF data transmission from %u to %u, %u blocks", srcId, dstId, m_rfAssembler->dataHeader.getBlocksToFollow());
                        LogInfoEx(LOG_RF, "P25 Data Call (Local Repeat), srcId = %u, dstId = %u", srcId, dstId);

                        if (m_verbose) {
                            LogInfoEx(LOG_RF, P25_PDU_STR ", repeating PDU, llId = %u", (m_rfAssembler->getExtendedAddress()) ? m_rfAssembler->dataHeader.getSrcLLId() : m_rfAssembler->dataHeader.getLLId());
                        }

                        writeRF_PDU_Buffered(); // re-generate buffered PDU and send it on
                        ::ActivityLog("P25", true, "end of RF data transmission");
                    }
                    break;
                }

                m_rfPDUCount = 0U;
                m_rfPDUBits = 0U;
                m_rfPduUserDataLength = 0U;
                ::memset(m_rfPDU, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);

                m_p25->m_rfState = RS_RF_LISTENING;
            }
        }

        m_inbound = false;
        return true;
    }
    else {
        LogError(LOG_RF, "P25 unhandled data DUID, duid = $%02X", duid);
    }

    return false;
}

/* Process a data frame from the network. */

bool Data::processNetwork(uint8_t* data, uint32_t len, uint8_t currentBlock, uint32_t blockLength, uint16_t totalBlocks)
{
    if (m_p25->m_netState != RS_NET_DATA) {
        m_p25->m_netState = RS_NET_DATA;
        m_inbound = false;
    }

    LogInfoEx(LOG_NET, P25_PDU_STR ", received block %u, len = %u, totalBlocks = %u",
        currentBlock, blockLength, totalBlocks);

    m_p25->m_networkWatchdog.start();

    // store the received block
    uint8_t* blockData = new uint8_t[blockLength];
    ::memcpy(blockData, data + 24U, blockLength);
    m_netReceivedBlocks[currentBlock] = blockData;
    m_netDataBlockCnt++;
    m_netTotalBlocks = totalBlocks;

    if (m_p25->m_netState == RS_NET_DATA) {
        if (m_netDataBlockCnt == m_netTotalBlocks) {
            for (uint16_t i = 0U; i < totalBlocks; i++) {
                if (m_netReceivedBlocks.find(i) != m_netReceivedBlocks.end()) {
                    // block 0 is always the PDU header block
                    if (i == 0U) {
                        bool ret = m_netAssembler->disassemble(m_netReceivedBlocks[i], blockLength, true);
                        if (!ret) {
                            m_p25->m_netState = RS_NET_IDLE;
                            m_p25->m_networkWatchdog.stop();
                            resetReceivedBlocks();
                            return false;
                        }

                        // if we're a dedicated CC or in control only mode, we only want to handle AMBTs. Otherwise return
                        if ((m_p25->m_dedicatedControl || m_p25->m_controlOnly) && m_netAssembler->dataHeader.getFormat() != PDUFormatType::AMBT) {
                            if (m_debug) {
                                LogDebug(LOG_NET, "CC only mode, ignoring non-AMBT PDU from network");
                            }

                            m_p25->m_netState = RS_NET_IDLE;
                            m_p25->m_networkWatchdog.stop();
                            resetReceivedBlocks();
                            return false;
                        }

                        // did we receive a response header?
                        if (m_netAssembler->dataHeader.getFormat() == PDUFormatType::RSP) {
                            m_p25->m_netState = RS_NET_IDLE;
                            m_p25->m_networkWatchdog.stop();

                            if (m_verbose) {
                                LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, fmt = $%02X, rspClass = $%02X, rspType = $%02X, rspStatus = $%02X, llId = %u, srcLlId = %u",
                                        m_netAssembler->dataHeader.getFormat(), m_netAssembler->dataHeader.getResponseClass(), m_netAssembler->dataHeader.getResponseType(), m_netAssembler->dataHeader.getResponseStatus(),
                                        m_netAssembler->dataHeader.getLLId(), m_netAssembler->dataHeader.getSrcLLId());

                                if (m_netAssembler->dataHeader.getResponseClass() == PDUAckClass::ACK && m_netAssembler->dataHeader.getResponseType() == PDUAckType::ACK) {
                                    LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, OSP ACK, llId = %u, all blocks received OK, n = %u",
                                        m_netAssembler->dataHeader.getLLId(), m_netAssembler->dataHeader.getResponseStatus());
                                } else {
                                    if (m_netAssembler->dataHeader.getResponseClass() == PDUAckClass::NACK) {
                                        switch (m_netAssembler->dataHeader.getResponseType()) {
                                            case PDUAckType::NACK_ILLEGAL:
                                                LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, OSP NACK, illegal format, llId = %u",
                                                    m_netAssembler->dataHeader.getLLId());
                                                break;
                                            case PDUAckType::NACK_PACKET_CRC:
                                                LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, OSP NACK, packet CRC error, llId = %u, n = %u",
                                                    m_netAssembler->dataHeader.getLLId(), m_netAssembler->dataHeader.getResponseStatus());
                                                break;
                                            case PDUAckType::NACK_SEQ:
                                            case PDUAckType::NACK_OUT_OF_SEQ:
                                                LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, OSP NACK, packet out of sequence, llId = %u, seqNo = %u",
                                                    m_netAssembler->dataHeader.getLLId(), m_netAssembler->dataHeader.getResponseStatus());
                                                break;
                                            case PDUAckType::NACK_UNDELIVERABLE:
                                                LogInfoEx(LOG_NET, P25_PDU_STR ", FNE ISP, response, OSP NACK, packet undeliverable, llId = %u, n = %u",
                                                    m_netAssembler->dataHeader.getLLId(), m_netAssembler->dataHeader.getResponseStatus());
                                                break;

                                            default:
                                                break;
                                            }
                                    }
                                }
                            }

                            writeRF_PDU_Ack_Response(m_netAssembler->dataHeader.getResponseClass(), m_netAssembler->dataHeader.getResponseType(), m_netAssembler->dataHeader.getResponseStatus(),
                                m_netAssembler->dataHeader.getLLId(), (m_netAssembler->dataHeader.getSrcLLId() > 0U), m_netAssembler->dataHeader.getSrcLLId());

                            resetReceivedBlocks();
                            return true;
                        }

                        continue;
                    }

                    bool ret = m_netAssembler->disassemble(m_netReceivedBlocks[i], blockLength);
                    if (!ret) {
                        m_p25->m_netState = RS_NET_IDLE;
                        m_p25->m_networkWatchdog.stop();
                        resetReceivedBlocks();
                        return false;
                    }
                    else {
                        if (m_netAssembler->getComplete()) {
                            m_netPduUserDataLength = m_netAssembler->getUserDataLength();
                            m_netAssembler->getUserData(m_netPduUserData);

                            uint32_t srcId = (m_netAssembler->getExtendedAddress()) ? m_netAssembler->dataHeader.getSrcLLId() : m_netAssembler->dataHeader.getLLId();
                            uint32_t dstId = m_netAssembler->dataHeader.getLLId();

                            uint8_t sap = (m_netAssembler->getExtendedAddress()) ? m_netAssembler->dataHeader.getEXSAP() : m_netAssembler->dataHeader.getSAP();
                            if (m_netAssembler->getAuxiliaryES())
                                sap = m_netAssembler->dataHeader.getEXSAP();

                            // handle standard P25 service access points
                            switch (sap) {
                        case PDUSAP::ARP:
                        {
                            if (m_netPduUserDataLength < P25_PDU_ARP_PCKT_LENGTH) {
                                LogWarning(LOG_NET, P25_PDU_STR ", ignoring truncated ARP payload, length = %u",
                                    m_netPduUserDataLength);
                                break;
                            }

                            /* bryanb: quick and dirty ARP logging */
                                uint8_t arpPacket[P25_PDU_ARP_PCKT_LENGTH];
                                ::memset(arpPacket, 0x00U, P25_PDU_ARP_PCKT_LENGTH);
                                ::memcpy(arpPacket, m_netPduUserData, P25_PDU_ARP_PCKT_LENGTH);

                                uint16_t opcode = GET_UINT16(arpPacket, 6U);
                                uint32_t srcHWAddr = GET_UINT24(arpPacket, 8U);
                                uint32_t srcProtoAddr = GET_UINT32(arpPacket, 11U);
                                //uint32_t tgtHWAddr = GET_UINT24(arpPacket, 15U);
                                uint32_t tgtProtoAddr = GET_UINT32(arpPacket, 18U);

                                if (m_verbose) {
                                    if (opcode == P25_PDU_ARP_REQUEST) {
                                        LogInfoEx(LOG_NET, P25_PDU_STR ", ARP request, who has %s? tell %s (%u)", __IP_FROM_UINT(tgtProtoAddr).c_str(), __IP_FROM_UINT(srcProtoAddr).c_str(), srcHWAddr);
                                    } else if (opcode == P25_PDU_ARP_REPLY) {
                                        LogInfoEx(LOG_NET, P25_PDU_STR ", ARP reply, %s is at %u", __IP_FROM_UINT(srcProtoAddr).c_str(), srcHWAddr);
                                    }
                                }

                                writeNet_PDU_Buffered(); // re-generate buffered PDU and send it on
                            }
                            break;
                            default:
                                ::ActivityLog("P25", false, "Net data transmission from %u to %u, %u blocks", srcId, dstId, m_netAssembler->dataHeader.getBlocksToFollow());
                                LogInfoEx(LOG_NET, "P25 Data Call, srcId = %u, dstId = %u", srcId, dstId);

                                if (m_verbose) {
                                    LogInfoEx(LOG_NET, P25_PDU_STR ", transmitting network PDU, llId = %u", (m_netAssembler->getExtendedAddress()) ? m_netAssembler->dataHeader.getSrcLLId() : m_netAssembler->dataHeader.getLLId());
                                }

                                writeNet_PDU_Buffered(); // re-generate buffered PDU and send it on

                                ::ActivityLog("P25", false, "end of Net data transmission");
                                break;
                            }

                            m_netPduUserDataLength = 0U;
                            m_p25->m_netState = RS_NET_IDLE;
                            m_p25->m_networkWatchdog.stop();
                            m_p25->m_network->resetP25();
                            resetReceivedBlocks();
                            break;
                        }
                    }
                }
            }
        }
    }

    return true;
}

/* Helper to reset received network blocks. */

void Data::resetReceivedBlocks()
{
    for (auto it : m_netReceivedBlocks) {
        if (it.second != nullptr) {
            delete[] it.second;
            it.second = nullptr;
        }
    }
    m_netReceivedBlocks.clear();

    m_netDataBlockCnt = 0U;
    m_netTotalBlocks = 0U;
}

/* Helper to write user data as a P25 PDU packet. */

void Data::writeRF_PDU_User(data::DataHeader& dataHeader, bool extendedAddress, bool auxiliaryES, uint8_t* pduUserData, bool imm)
{
    assert(pduUserData != nullptr);

    m_p25->writeRF_TDU(true, imm);

    uint32_t bitLength = 0U;
    UInt8Array data = m_rfAssembler->assemble(dataHeader, extendedAddress, auxiliaryES, pduUserData, &bitLength);

    bool trackRetry = dataHeader.getFormat() == PDUFormatType::CONFIRMED && dataHeader.getAckNeeded();
    writeRF_PDU(data.get(), bitLength, imm, false, dataHeader.getLLId(), trackRetry);
}

/* Helper to write user data as a P25 PDU packet. */

void Data::writeNet_PDU_User(data::DataHeader& dataHeader, bool extendedAddress, bool auxiliaryES, uint8_t* pduUserData)
{
    assert(pduUserData != nullptr);

    uint32_t bitLength = 0U;
    m_netAssembler->assemble(dataHeader, extendedAddress, auxiliaryES, pduUserData, &bitLength);
}

/* Updates the processor by the passed number of milliseconds. */

void Data::clock(uint32_t ms)
{
    if (m_p25->m_sndcpSupport) {
        // clock all the SNDCP ready timers
        std::vector<uint32_t> sndcpReadyExpired = std::vector<uint32_t>();
        for (auto entry : m_sndcpReadyTimers) {
            uint32_t llId = entry.first;

            m_sndcpReadyTimers[llId].clock(ms);
            if (m_sndcpReadyTimers[llId].isRunning() && m_sndcpReadyTimers[llId].hasExpired()) {
                sndcpReadyExpired.push_back(llId);
            }
        }

        // clock all the SNDCP standby timers
        std::vector<uint32_t> sndcpStandbyExpired = std::vector<uint32_t>();
        for (auto entry : m_sndcpStandbyTimers) {
            uint32_t llId = entry.first;

            m_sndcpStandbyTimers[llId].clock(ms);
            if (m_sndcpStandbyTimers[llId].isRunning() && m_sndcpStandbyTimers[llId].hasExpired()) {
                sndcpStandbyExpired.push_back(llId);
            }
        }

        // process and SNDCP enabled LLIDs
        for (auto entry : m_sndcpStateTable) {
            uint32_t llId = entry.first;
            SNDCPState::E state = entry.second;

            switch (state) {
            case SNDCPState::CLOSED:
                break;
            case SNDCPState::IDLE:
                {
                    if (m_p25->m_permittedDstId == llId) {
                        m_sndcpReadyTimers[llId].start();
                        m_sndcpStateTable[llId] = SNDCPState::READY_S;
                        if (m_verbose) {
                            LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP, llId = %u, state = %u", llId, (uint8_t)state);
                        }
                    }
                }
                break;
            case SNDCPState::READY_S:
                {
                    // has the LLID reached ready state expiration?
                    if (std::find(sndcpReadyExpired.begin(), sndcpReadyExpired.end(), llId) != sndcpReadyExpired.end()) {
                        // transition to STANDBY per TIA-102 (preserves context)
                        m_sndcpStateTable[llId] = SNDCPState::STANDBY;
                        m_sndcpReadyTimers[llId].stop();
                        m_sndcpStandbyTimers[llId].start();
                        
                        if (m_verbose) {
                            LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP state transition, llId = %u, READY_S -> STANDBY", llId);
                        }
                    }
                }
                break;
            case SNDCPState::STANDBY:
                {
                    // has the LLID reached standby state expiration?
                    if (std::find(sndcpStandbyExpired.begin(), sndcpStandbyExpired.end(), llId) != sndcpStandbyExpired.end()) {
                        sndcpReset(llId);
                    }
                }
                break;
            case SNDCPState::READY:
                break;
            default:
                break;
            }
        }
    }
}

/* Helper to initialize the SNDCP state for a logical link ID. */

void Data::sndcpInitialize(uint32_t llId)
{
    if (!isSNDCPInitialized(llId)) {
        m_sndcpStateTable[llId] = SNDCPState::IDLE;
        m_sndcpReadyTimers[llId] = Timer(1000U, SNDCP_READY_TIMEOUT);
        m_sndcpStandbyTimers[llId] = Timer(1000U, SNDCP_STANDBY_TIMEOUT);

        if (m_verbose) {
            LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP, first initialize, llId = %u, state = %u", llId, (uint8_t)SNDCPState::IDLE);
        }
    }
}

/* Helper to determine if the logical link ID has been SNDCP initialized. */

bool Data::isSNDCPInitialized(uint32_t llId) const
{
    // lookup dynamic affiliation table entry
    if (m_sndcpStateTable.find(llId) != m_sndcpStateTable.end()) {
        return true;
    }

    return false;
}

/* Helper to reset the SNDCP state for a logical link ID. */

void Data::sndcpReset(uint32_t llId, bool callTerm)
{
    if (isSNDCPInitialized(llId)) {
        if (m_verbose) {
            LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP, reset, llId = %u, state = %u", llId, (uint8_t)m_sndcpStateTable[llId]);
        }

        m_sndcpStateTable[llId] = SNDCPState::CLOSED;
        m_sndcpReadyTimers[llId].stop();
        m_sndcpStandbyTimers[llId].stop();

        if (callTerm) {
            if (m_verbose) {
                LogInfoEx(LOG_RF, P25_TDULC_STR ", CALL_TERM (Call Termination), llId = %u", llId);
            }

            std::unique_ptr<lc::TDULC> lc = std::make_unique<lc::tdulc::LC_CALL_TERM>();
            lc->setDstId(llId);
            m_p25->m_control->writeRF_TDULC(lc.get(), true);
            m_p25->writeRF_Preamble();

            if (m_p25->m_notifyCC) {
                m_p25->notifyCC_ReleaseGrant(llId);
            }
        }
    }
}

// ---------------------------------------------------------------------------
//  Private Class Members
// ---------------------------------------------------------------------------

/* Initializes a new instance of the Data class. */

Data::Data(Control* p25, bool dumpPDUData, bool repeatPDU, bool debug, bool verbose) :
    m_p25(p25),
    m_prevRfState(RS_RF_LISTENING),
    m_rfAssembler(nullptr),
    m_rfPDU(nullptr),
    m_rfPDUCount(0U),
    m_rfPDUBits(0U),
    m_netAssembler(nullptr),
    m_netReceivedBlocks(),
    m_netDataBlockCnt(0U),
    m_netTotalBlocks(0U),
    m_retryPDUState(),
    m_rfPduUserData(nullptr),
    m_rfPduUserDataLength(0U),
    m_netPduUserData(nullptr),
    m_netPduUserDataLength(0U),
    m_sndcpStateTable(),
    m_sndcpReadyTimers(),
    m_sndcpStandbyTimers(),
    m_inbound(false),
    m_dumpPDUData(dumpPDUData),
    m_repeatPDU(repeatPDU),
    m_verbose(verbose),
    m_debug(debug)
{
    data::Assembler::setVerbose(verbose);
    data::Assembler::setDumpPDUData(dumpPDUData);

    m_rfAssembler = new Assembler();
    m_netAssembler = new Assembler();

    m_rfPDU = new uint8_t[P25_PDU_FRAME_LENGTH_BYTES + 2U];
    ::memset(m_rfPDU, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);

    m_netAssembler->setBlockWriter([=](const void* userContext, const uint8_t currentBlock, const uint8_t *data, uint32_t len, bool lastBlock) {
        writeNetwork(currentBlock, data, len, lastBlock);
    });

    m_rfPduUserData = new uint8_t[P25_MAX_PDU_BLOCKS * P25_PDU_CONFIRMED_LENGTH_BYTES + 2U];
    ::memset(m_rfPduUserData, 0x00U, P25_MAX_PDU_BLOCKS * P25_PDU_CONFIRMED_LENGTH_BYTES + 2U);
    m_netPduUserData = new uint8_t[P25_MAX_PDU_BLOCKS * P25_PDU_CONFIRMED_LENGTH_BYTES + 2U];
    ::memset(m_netPduUserData, 0x00U, P25_MAX_PDU_BLOCKS * P25_PDU_CONFIRMED_LENGTH_BYTES + 2U);

    m_sndcpStateTable.clear();
    m_sndcpReadyTimers.clear();
    m_sndcpStandbyTimers.clear();
}

/* Finalizes a instance of the Data class. */

Data::~Data()
{
    delete m_rfAssembler;
    delete m_netAssembler;

    delete[] m_rfPDU;

    delete[] m_rfPduUserData;
    delete[] m_netPduUserData;
}

/* Helper used to process conventional data registration from PDU data. */

bool Data::processConvDataReg(const uint8_t* pduUserData, uint32_t length)
{
    if (pduUserData == nullptr || length < ConventionalRegistration::DISCONNECT_LENGTH) {
        LogError(LOG_RF, P25_PDU_STR ", truncated conventional registration payload, length = %u", length);
        return false;
    }

    ConventionalRegistration registration;
    if (!ConventionalRegistration::decode(pduUserData, length, registration)) {
        LogError(LOG_RF, P25_PDU_STR ", invalid conventional registration payload");
        return false;
    }

    if (registration.type != PDURegType::CONNECT &&
        registration.type != PDURegType::DISCONNECT)
        return false;

    uint32_t headerLlId = m_rfAssembler->getExtendedAddress() ?
        m_rfAssembler->dataHeader.getSrcLLId() : m_rfAssembler->dataHeader.getLLId();
    if (headerLlId != 0U && headerLlId != registration.llId) {
        LogWarning(LOG_RF, P25_PDU_STR ", conventional registration identity mismatch, header = %u, payload = %u",
            headerLlId, registration.llId);
        return false;
    }

    // authorization and the ACCEPT/DENY response are FNE-owned -- returning true
    // here only permits this validated request to be forwarded to that service
    return true;
}

/* Helper used to process SNDCP control data from PDU data. */

bool Data::processSNDCPControl(const uint8_t* pduUserData)
{
    if (!m_p25->m_sndcpSupport) {
        return false;
    }

    std::unique_ptr<sndcp::SNDCPPacket> packet = SNDCPFactory::create(pduUserData);
    if (packet == nullptr) {
        LogWarning(LOG_RF, P25_PDU_STR ", undecodable SNDCP packet");
        return false;
    }

    uint32_t llId = m_rfAssembler->dataHeader.getLLId();

    switch (packet->getPDUType()) {
        case SNDCP_PDUType::ACT_TDS_CTX:
        {
            SNDCPCtxActRequest* isp = static_cast<SNDCPCtxActRequest*>(packet.get());
            if (m_verbose) {
                LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP context activation request, llId = %u, nsapi = %u, ipAddr = %s, nat = $%02X, dsut = $%02X, mdpco = $%02X", llId,
                    isp->getNSAPI(), __IP_FROM_UINT(isp->getIPAddress()).c_str(), isp->getNAT(), isp->getDSUT(), isp->getMDPCO());
            }
            
            // initialize SNDCP state if not already done
            if (!isSNDCPInitialized(llId)) {
                sndcpInitialize(llId);
            }
        }
        break;

        case SNDCP_PDUType::DEACT_TDS_CTX_REQ:
        {
            SNDCPCtxDeactivation* isp = static_cast<SNDCPCtxDeactivation*>(packet.get());
            if (m_verbose) {
                LogInfoEx(LOG_RF, P25_PDU_STR ", SNDCP context deactivation request, llId = %u, deactType = %02X", llId,
                    isp->getDeactType());
            }
            
            // reset local SNDCP state (FNE will handle response)
            sndcpReset(llId, false); // don't send CALL_TERM here
        }
        break;

        default:
        {
            LogError(LOG_RF, P25_PDU_STR ", unhandled SNDCP PDU Type, pduType = $%02X", packet->getPDUType());
        }
        break;
    } // switch (packet->getPDUType())

    // always forward SNDCP control to FNE for processing
    // FNE will generate the accept/reject response
    return true;
}

/* Write data processed from RF to the network. */

void Data::writeNetwork(const uint8_t currentBlock, const uint8_t* data, uint32_t len, bool lastBlock)
{
    assert(data != nullptr);

    if (m_p25->m_network == nullptr)
        return;

    if (m_p25->m_rfTimeoutTimer.isRunning() && m_p25->m_rfTimeoutTimer.hasExpired())
        return;

    m_p25->m_network->writeP25PDU(m_rfAssembler->dataHeader, currentBlock, data, len, lastBlock);
}

/* Helper to write a P25 PDU packet. */

void Data::writeRF_PDU(const uint8_t* pdu, uint32_t bitLength, bool imm, bool ackRetry,
    uint32_t retryLlId, bool trackRetry)
{
    assert(pdu != nullptr);
    assert(bitLength > 0U);

    m_p25->writeRF_TDU(true, imm);

    for (uint8_t i = 0U; i < 5U; i++)
        m_p25->writeRF_Nulls();

    if (!ackRetry && trackRetry && retryLlId != 0U) {
        // store confirmed transactions independently per logical link
        uint32_t retryByteLength = bitLength / 8U;
        if ((bitLength % 8U) > 0U)
            retryByteLength++;

        RetryPDUState& retry = m_retryPDUState[retryLlId];
        retry.data.assign(pdu, pdu + retryByteLength);
        retry.bitLength = bitLength;
        retry.retryCount = 0U;
    } else if (ackRetry) {
        LogInfoEx(LOG_RF, P25_PDU_STR ", OSP, ack retry, bitLength = %u", bitLength);
    }

    uint8_t data[P25_PDU_FRAME_LENGTH_BYTES + 2U];
    ::memset(data, 0x00U, P25_PDU_FRAME_LENGTH_BYTES + 2U);

    // add the data
    uint32_t newBitLength = P25Utils::encodeByLength(pdu, data + 2U, bitLength);
    uint32_t newByteLength = newBitLength / 8U;
    if ((newBitLength % 8U) > 0U)
        newByteLength++;

    // generate Sync
    Sync::addP25Sync(data + 2U);

    // generate NID
    m_p25->m_nid.encode(data + 2U, DUID::PDU);

    // add status bits
    P25Utils::addStatusBits(data + 2U, newBitLength, m_inbound, true);
    P25Utils::setStatusBitsStartIdle(data + 2U);

    //Utils::dump("P25, Data::writeRF_PDU(), Raw PDU OSP", data, newByteLength + 2U);

    if (m_p25->m_duplex) {
        data[0U] = modem::TAG_DATA;
        data[1U] = 0x00U;

        m_p25->addFrame(data, newByteLength + 2U, false, imm);
    }

    m_p25->writeRF_TDU(true, imm);
}

/* Helper to write a network P25 PDU packet. */

void Data::writeNet_PDU_Buffered()
{
    uint32_t bitLength = 0U;
    UInt8Array data = m_rfAssembler->assemble(m_netAssembler->dataHeader, m_netAssembler->getExtendedAddress(), m_netAssembler->getAuxiliaryES(), m_netPduUserData, &bitLength);
    bool trackRetry = m_netAssembler->dataHeader.getFormat() == PDUFormatType::CONFIRMED && m_netAssembler->dataHeader.getAckNeeded();

    writeRF_PDU(data.get(), bitLength, false, false, m_netAssembler->dataHeader.getLLId(), trackRetry);
}

/* Helper to re-write a received P25 PDU packet. */

void Data::writeRF_PDU_Buffered()
{
    uint32_t bitLength = 0U;
    UInt8Array data = m_rfAssembler->assemble(m_rfAssembler->dataHeader, m_rfAssembler->getExtendedAddress(), m_rfAssembler->getAuxiliaryES(), m_rfPduUserData, &bitLength);
    writeRF_PDU(data.get(), bitLength);
}

/* Helper to write a PDU acknowledge response. */

void Data::writeRF_PDU_Ack_Response(uint8_t ackClass, uint8_t ackType, uint8_t ackStatus, uint32_t llId, bool extendedAddress, uint32_t srcLlId)
{
    if (ackClass == PDUAckClass::ACK && ackType != PDUAckType::ACK)
        return;

    uint32_t bitLength = (1U * P25_PDU_FEC_LENGTH_BITS) + P25_PREAMBLE_LENGTH_BITS;
    uint32_t offset = P25_PREAMBLE_LENGTH_BITS;

    DECLARE_UINT8_ARRAY(data, (bitLength / 8U) + 1U);

    uint8_t block[P25_PDU_FEC_LENGTH_BYTES];
    ::memset(block, 0x00U, P25_PDU_FEC_LENGTH_BYTES);

    DataHeader rspHeader = DataHeader();
    rspHeader.setFormat(PDUFormatType::RSP);
    rspHeader.setMFId(m_rfAssembler->dataHeader.getMFId());
    rspHeader.setOutbound(true);
    rspHeader.setResponseClass(ackClass);
    rspHeader.setResponseType(ackType);
    rspHeader.setResponseStatus(ackStatus);
    rspHeader.setLLId(llId);
    if (srcLlId > 0U) {
        rspHeader.setSrcLLId(srcLlId);
    }

    if (extendedAddress)
        rspHeader.setFullMessage(false);
    else
        rspHeader.setFullMessage(true);

    rspHeader.setBlocksToFollow(0U);

    // generate the PDU header and 1/2 rate Trellis
    rspHeader.encode(block);
    Utils::setBitRange(block, data, offset, P25_PDU_FEC_LENGTH_BITS);

    if (m_verbose) {
        LogInfoEx(LOG_RF, P25_PDU_STR ", OSP, response, rspClass = $%02X, rspType = $%02X, rspStatus = $%02X, llId = %u, srcLLId = %u",
            rspHeader.getResponseClass(), rspHeader.getResponseType(), rspHeader.getResponseStatus(), rspHeader.getLLId(), rspHeader.getSrcLLId());
    }

    writeRF_PDU(data, bitLength);
}