MMDVMHost-Private/M17Control.cpp
2020-12-26 12:12:52 +00:00

802 lines
22 KiB
C++

/*
* Copyright (C) 2015-2020 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; version 2 of the License.
*
* 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.
*/
#include "M17Control.h"
#include "M17Convolution.h"
#include "M17Utils.h"
#include "M17CRC.h"
#include "Golay24128.h"
#include "Utils.h"
#include "Sync.h"
#include "Log.h"
#include <cstdio>
#include <cassert>
#include <cstring>
#include <ctime>
const unsigned int INTERLEAVER[] = {
0U, 137U, 90U, 227U, 180U, 317U, 270U, 39U, 360U, 129U, 82U, 219U, 172U, 309U, 262U, 31U, 352U, 121U, 74U, 211U, 164U,
301U, 254U, 23U, 344U, 113U, 66U, 203U, 156U, 293U, 246U, 15U, 336U, 105U, 58U, 195U, 148U, 285U, 238U, 7U, 328U, 97U,
50U, 187U, 140U, 277U, 230U, 367U, 320U, 89U, 42U, 179U, 132U, 269U, 222U, 359U, 312U, 81U, 34U, 171U, 124U, 261U, 214U,
351U, 304U, 73U, 26U, 163U, 116U, 253U, 206U, 343U, 296U, 65U, 18U, 155U, 108U, 245U, 198U, 335U, 288U, 57U, 10U, 147U,
100U, 237U, 190U, 327U, 280U, 49U, 2U, 139U, 92U, 229U, 182U, 319U, 272U, 41U, 362U, 131U, 84U, 221U, 174U, 311U, 264U,
33U, 354U, 123U, 76U, 213U, 166U, 303U, 256U, 25U, 346U, 115U, 68U, 205U, 158U, 295U, 248U, 17U, 338U, 107U, 60U, 197U,
150U, 287U, 240U, 9U, 330U, 99U, 52U, 189U, 142U, 279U, 232U, 1U, 322U, 91U, 44U, 181U, 134U, 271U, 224U, 361U, 314U, 83U,
36U, 173U, 126U, 263U, 216U, 353U, 306U, 75U, 28U, 165U, 118U, 255U, 208U, 345U, 298U, 67U, 20U, 157U, 110U, 247U, 200U,
337U, 290U, 59U, 12U, 149U, 102U, 239U, 192U, 329U, 282U, 51U, 4U, 141U, 94U, 231U, 184U, 321U, 274U, 43U, 364U, 133U, 86U,
223U, 176U, 313U, 266U, 35U, 356U, 125U, 78U, 215U, 168U, 305U, 258U, 27U, 348U, 117U, 70U, 207U, 160U, 297U, 250U, 19U,
340U, 109U, 62U, 199U, 152U, 289U, 242U, 11U, 332U, 101U, 54U, 191U, 144U, 281U, 234U, 3U, 324U, 93U, 46U, 183U, 136U, 273U,
226U, 363U, 316U, 85U, 38U, 175U, 128U, 265U, 218U, 355U, 308U, 77U, 30U, 167U, 120U, 257U, 210U, 347U, 300U, 69U, 22U,
159U, 112U, 249U, 202U, 339U, 292U, 61U, 14U, 151U, 104U, 241U, 194U, 331U, 284U, 53U, 6U, 143U, 96U, 233U, 186U, 323U,
276U, 45U, 366U, 135U, 88U, 225U, 178U, 315U, 268U, 37U, 358U, 127U, 80U, 217U, 170U, 307U, 260U, 29U, 350U, 119U, 72U,
209U, 162U, 299U, 252U, 21U, 342U, 111U, 64U, 201U, 154U, 291U, 244U, 13U, 334U, 103U, 56U, 193U, 146U, 283U, 236U, 5U,
326U, 95U, 48U, 185U, 138U, 275U, 228U, 365U, 318U, 87U, 40U, 177U, 130U, 267U, 220U, 357U, 310U, 79U, 32U, 169U, 122U,
259U, 212U, 349U, 302U, 71U, 24U, 161U, 114U, 251U, 204U, 341U, 294U, 63U, 16U, 153U, 106U, 243U, 196U, 333U, 286U, 55U,
8U, 145U, 98U, 235U, 188U, 325U, 278U, 47U};
const unsigned char SCRAMBLER[] = {
0x00U, 0x00U, 0xD6U, 0xB5U, 0xE2U, 0x30U, 0x82U, 0xFFU, 0x84U, 0x62U, 0xBAU, 0x4EU, 0x96U, 0x90U, 0xD8U, 0x98U, 0xDDU,
0x5DU, 0x0CU, 0xC8U, 0x52U, 0x43U, 0x91U, 0x1DU, 0xF8U, 0x6EU, 0x68U, 0x2FU, 0x35U, 0xDAU, 0x14U, 0xEAU, 0xCDU, 0x76U,
0x19U, 0x8DU, 0xD5U, 0x80U, 0xD1U, 0x33U, 0x87U, 0x13U, 0x57U, 0x18U, 0x2DU, 0x29U, 0x78U, 0xC3U};
// #define DUMP_M17
const unsigned char BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
#define WRITE_BIT(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
#define READ_BIT(p,i) (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
CM17Control::CM17Control(const std::string& callsign, unsigned int colorCode, bool selfOnly, bool allowEncryption, CM17Network* network, CDisplay* display, unsigned int timeout, bool duplex, CRSSIInterpolator* rssiMapper) :
m_callsign(callsign),
m_colorCode(colorCode),
m_selfOnly(selfOnly),
m_allowEncryption(allowEncryption),
m_network(network),
m_display(display),
m_duplex(duplex),
m_queue(5000U, "M17 Control"),
m_rfState(RS_RF_LISTENING),
m_netState(RS_NET_IDLE),
m_rfTimeoutTimer(1000U, timeout),
m_netTimeoutTimer(1000U, timeout),
m_packetTimer(1000U, 0U, 200U),
m_networkWatchdog(1000U, 0U, 1500U),
m_elapsed(),
m_rfFrames(0U),
m_netFrames(0U),
m_rfFN(0U),
m_rfErrs(0U),
m_rfBits(1U),
m_rfLICH(),
m_rfLICHn(0U),
m_netLICH(),
m_netLICHn(0U),
m_rssiMapper(rssiMapper),
m_rssi(0U),
m_maxRSSI(0U),
m_minRSSI(0U),
m_aveRSSI(0U),
m_rssiCount(0U),
m_enabled(true),
m_fp(NULL)
{
assert(display != NULL);
assert(rssiMapper != NULL);
}
CM17Control::~CM17Control()
{
}
bool CM17Control::writeModem(unsigned char* data, unsigned int len)
{
assert(data != NULL);
if (!m_enabled)
return false;
unsigned char type = data[0U];
if (type == TAG_LOST && m_rfState == RS_RF_AUDIO) {
std::string source = m_rfLICH.getSource();
std::string dest = m_rfLICH.getDest();
if (m_rssi != 0U)
LogMessage("M17, transmission lost from %s to %s, %.1f seconds, BER: %.1f%%, RSSI: -%u/-%u/-%u dBm", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits), m_minRSSI, m_maxRSSI, m_aveRSSI / m_rssiCount);
else
LogMessage("M17, transmission lost from %s to %s, %.1f seconds, BER: %.1f%%", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits));
writeEndRF();
return false;
}
if (type == TAG_LOST && m_rfState == RS_RF_DATA) {
writeEndRF();
return false;
}
if (type == TAG_LOST) {
m_rfState = RS_RF_LISTENING;
return false;
}
// Have we got RSSI bytes on the end?
if (len == (M17_FRAME_LENGTH_BYTES + 4U)) {
uint16_t raw = 0U;
raw |= (data[50U] << 8) & 0xFF00U;
raw |= (data[51U] << 0) & 0x00FFU;
// Convert the raw RSSI to dBm
int rssi = m_rssiMapper->interpolate(raw);
if (rssi != 0)
LogDebug("M17, raw RSSI: %u, reported RSSI: %d dBm", raw, rssi);
// RSSI is always reported as positive
m_rssi = (rssi >= 0) ? rssi : -rssi;
if (m_rssi > m_minRSSI)
m_minRSSI = m_rssi;
if (m_rssi < m_maxRSSI)
m_maxRSSI = m_rssi;
m_aveRSSI += m_rssi;
m_rssiCount++;
}
unsigned char temp[M17_FRAME_LENGTH_BYTES];
decorrelator(data + 2U, temp);
interleaver(temp, data + 2U);
if (m_rfState == RS_RF_LISTENING && data[0U] == TAG_HEADER) {
m_rfLICH.reset();
CM17Convolution conv;
unsigned char frame[M17_LICH_LENGTH_BYTES];
conv.decodeLinkSetup(data + 2U + M17_SYNC_LENGTH_BYTES, frame);
bool valid = CM17CRC::checkCRC(frame, M17_LICH_LENGTH_BYTES);
if (valid) {
m_rfFrames = 0U;
m_rfErrs = 0U;
m_rfBits = 1U;
m_rfTimeoutTimer.start();
m_minRSSI = m_rssi;
m_maxRSSI = m_rssi;
m_aveRSSI = m_rssi;
m_rssiCount = 1U;
m_rfLICHn = 0U;
m_rfFN = 0U;
#if defined(DUMP_M17)
openFile();
#endif
m_rfLICH.setLinkSetup(frame);
m_rfState = RS_RF_LATE_ENTRY;
return true;
} else {
m_rfState = RS_RF_LATE_ENTRY;
}
}
if (m_rfState == RS_RF_LATE_ENTRY && data[0U] == TAG_DATA) {
unsigned int frag1, frag2, frag3, frag4;
CM17Utils::splitFragmentLICHFEC(data + 2U + M17_SYNC_LENGTH_BYTES, frag1, frag2, frag3, frag4);
unsigned int lich1 = CGolay24128::decode24128(frag1);
unsigned int lich2 = CGolay24128::decode24128(frag2);
unsigned int lich3 = CGolay24128::decode24128(frag3);
unsigned int lich4 = CGolay24128::decode24128(frag4);
unsigned int colorCode = (lich4 >> 7) & 0x1FU;
if (colorCode != m_colorCode)
return false;
bool lateEntry = false;
if (!m_rfLICH.isValid()) {
unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich);
unsigned int n = (lich4 >> 4) & 0x07U;
m_rfLICH.setFragment(lich, n);
lateEntry = true;
}
bool valid = m_rfLICH.isValid();
if (valid) {
m_rfFrames = 0U;
m_rfErrs = 0U;
m_rfBits = 1U;
m_rfTimeoutTimer.start();
m_minRSSI = m_rssi;
m_maxRSSI = m_rssi;
m_aveRSSI = m_rssi;
m_rssiCount = 1U;
m_rfLICHn = 0U;
#if defined(DUMP_M17)
openFile();
#endif
std::string source = m_rfLICH.getSource();
std::string dest = m_rfLICH.getDest();
if (m_selfOnly) {
bool ret = checkCallsign(source);
if (!ret) {
LogMessage("M17, invalid access attempt from %s to %s", source.c_str(), dest.c_str());
m_rfState = RS_RF_REJECTED;
return false;
}
}
unsigned char dataType = m_rfLICH.getDataType();
switch (dataType) {
case 1U:
LogMessage("M17, received RF %s data transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
m_rfState = RS_RF_DATA;
break;
case 2U:
LogMessage("M17, received RF %s voice transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
m_rfState = RS_RF_AUDIO;
break;
case 3U:
LogMessage("M17, received RF %s voice + data transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
m_rfState = RS_RF_AUDIO;
break;
default:
LogMessage("M17, received RF %s unknown transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
m_rfState = RS_RF_DATA;
break;
}
m_display->writeM17(source.c_str(), dest.c_str(), "R");
if (m_duplex) {
// Create a Link Setup frame
data[0U] = TAG_HEADER;
data[1U] = 0x00U;
// Generate the sync
CSync::addM17LinkSetupSync(data + 2U);
unsigned char setup[M17_LICH_LENGTH_BYTES];
m_rfLICH.getLinkSetup(setup);
// Add the convolution FEC
CM17Convolution conv;
conv.encodeLinkSetup(setup, data + 2U + M17_SYNC_LENGTH_BYTES);
unsigned char temp[M17_FRAME_LENGTH_BYTES];
interleaver(data + 2U, temp);
decorrelator(temp, data + 2U);
writeQueueRF(data);
}
// Fall through to the next section
}
}
if ((m_rfState == RS_RF_AUDIO || m_rfState == RS_RF_DATA) && data[0U] == TAG_DATA) {
#if defined(DUMP_M17)
writeFile(data + 2U);
#endif
CM17Convolution conv;
unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
bool valid = CM17CRC::checkCRC(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
if (valid) {
m_rfFN = (frame[0U] << 8) + (frame[1U] << 0);
} else {
// Create a silence frame
m_rfFN++;
// The new FN
frame[0U] = m_rfFN >> 8;
frame[1U] = m_rfFN >> 0;
// Add silent audio
unsigned char dataType = m_rfLICH.getDataType();
switch (dataType) {
case 2U:
::memcpy(frame + M17_FN_LENGTH_BYTES + 0U, M17_3200_SILENCE, 8U);
::memcpy(frame + M17_FN_LENGTH_BYTES + 8U, M17_3200_SILENCE, 8U);
break;
case 3U:
::memcpy(frame + M17_FN_LENGTH_BYTES + 0U, M17_1600_SILENCE, 8U);
break;
default:
break;
}
// Add the CRC
CM17CRC::encodeCRC(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
}
unsigned char rfData[2U + M17_FRAME_LENGTH_BYTES];
rfData[0U] = TAG_DATA;
rfData[1U] = 0x00U;
// Generate the sync
CSync::addM17StreamSync(rfData + 2U);
unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
m_netLICH.getFragment(lich, m_rfLICHn);
unsigned int frag1, frag2, frag3, frag4;
CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
// Add the Color Code and fragment number
frag4 |= (m_rfLICHn & 0x07U) << 4;
frag4 |= (m_colorCode & 0x1FU) << 7;
// Add Golay to the LICH fragment here
unsigned int lich1 = CGolay24128::encode24128(frag1);
unsigned int lich2 = CGolay24128::encode24128(frag2);
unsigned int lich3 = CGolay24128::encode24128(frag3);
unsigned int lich4 = CGolay24128::encode24128(frag4);
CM17Utils::combineFragmentLICHFEC(lich1, lich2, lich3, lich4, rfData + 2U + M17_SYNC_LENGTH_BYTES);
// Add the Convolution FEC
conv.encodeData(frame, rfData + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);
// Calculate the BER
if (valid) {
unsigned int errors = 0U;
for (unsigned int i = 2U; i < (M17_FRAME_LENGTH_BYTES + 2U); i++)
errors += countBits(rfData[i] ^ data[i]);
LogDebug("M17, FN: %u, errs: %u/384 (%.1f%%)", m_rfFN, errors, float(errors) / 3.84F);
m_rfBits += M17_FRAME_LENGTH_BITS;
m_rfErrs += errors;
float ber = float(m_rfErrs) / float(m_rfBits);
m_display->writeM17BER(ber);
}
unsigned char temp[M17_FRAME_LENGTH_BYTES];
interleaver(rfData + 2U, temp);
decorrelator(rfData, data + 2U);
if (m_duplex)
writeQueueRF(rfData);
unsigned char netData[M17_LICH_LENGTH_BYTES + M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
m_rfLICH.getNetwork(netData + 0U);
// Copy the FN and payload from the frame
::memcpy(netData + M17_LICH_LENGTH_BYTES - M17_CRC_LENGTH_BYTES, frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES);
// The CRC is added in the networking code
writeNetwork(netData);
m_rfFrames++;
m_rfLICHn++;
if (m_rfLICHn >= 6U)
m_rfLICHn = 0U;
// EOT?
if ((m_rfFN & 0x8000U) == 0x8000U) {
std::string source = m_rfLICH.getSource();
std::string dest = m_rfLICH.getDest();
if (m_rssi != 0U)
LogMessage("M17, received RF end of transmission from %s to %s, %.1f seconds, BER: %.1f%%, RSSI: -%u/-%u/-%u dBm", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits), m_minRSSI, m_maxRSSI, m_aveRSSI / m_rssiCount);
else
LogMessage("M17, received RF end of transmission from %s to %s, %.1f seconds, BER: %.1f%%", source.c_str(), dest.c_str(), float(m_rfFrames) / 25.0F, float(m_rfErrs * 100U) / float(m_rfBits));
writeEndRF();
}
return true;
}
if (m_rfState == RS_RF_REJECTED && data[0U] == TAG_DATA) {
CM17Convolution conv;
unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
bool valid = CM17CRC::checkCRC(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
if (valid) {
// Handle the EOT for rejected frames
unsigned int fn = (frame[0U] << 8) + (frame[1U] << 0);
if ((fn & 0x8000U) == 0x8000U)
writeEndRF();
}
return false;
}
return false;
}
unsigned int CM17Control::readModem(unsigned char* data)
{
assert(data != NULL);
if (m_queue.isEmpty())
return 0U;
unsigned char len = 0U;
m_queue.getData(&len, 1U);
m_queue.getData(data, len);
return len;
}
void CM17Control::writeEndRF()
{
m_rfState = RS_RF_LISTENING;
m_rfTimeoutTimer.stop();
m_rfLICH.reset();
if (m_netState == RS_NET_IDLE) {
m_display->clearM17();
if (m_network != NULL)
m_network->reset();
}
#if defined(DUMP_M17)
closeFile();
#endif
}
void CM17Control::writeEndNet()
{
m_netState = RS_NET_IDLE;
m_netTimeoutTimer.stop();
m_networkWatchdog.stop();
m_packetTimer.stop();
m_netLICH.reset();
m_display->clearM17();
if (m_network != NULL)
m_network->reset();
}
void CM17Control::writeNetwork()
{
unsigned char netData[100U];
bool exists = m_network->read(netData);
if (!exists)
return;
if (!m_enabled)
return;
if (m_rfState != RS_RF_LISTENING && m_netState == RS_NET_IDLE)
return;
m_networkWatchdog.start();
m_netLICH.setNetwork(netData);
if (!m_allowEncryption) {
bool ret = m_rfLICH.isNONCENull();
if (!ret)
return;
}
if (m_netState == RS_NET_IDLE) {
std::string source = m_netLICH.getSource();
std::string dest = m_netLICH.getDest();
unsigned char dataType = m_netLICH.getDataType();
switch (dataType) {
case 1U:
LogMessage("M17, received network data transmission from %s to %s", source.c_str(), dest.c_str());
m_netState = RS_NET_DATA;
break;
case 2U:
LogMessage("M17, received network voice transmission from %s to %s", source.c_str(), dest.c_str());
m_netState = RS_NET_AUDIO;
break;
case 3U:
LogMessage("M17, received network voice + data transmission from %s to %s", source.c_str(), dest.c_str());
m_netState = RS_NET_AUDIO;
break;
default:
LogMessage("M17, received network unknown transmission from %s to %s", source.c_str(), dest.c_str());
m_netState = RS_NET_DATA;
break;
}
m_display->writeM17(source.c_str(), dest.c_str(), "N");
m_netTimeoutTimer.start();
m_packetTimer.start();
m_elapsed.start();
m_netFrames = 0U;
m_netLICHn = 0U;
// Create a dummy start message
unsigned char start[M17_FRAME_LENGTH_BYTES + 2U];
start[0U] = TAG_HEADER;
start[1U] = 0x00U;
// Generate the sync
CSync::addM17LinkSetupSync(start + 2U);
unsigned char setup[M17_LICH_LENGTH_BYTES];
m_netLICH.getLinkSetup(setup);
// Add the convolution FEC
CM17Convolution conv;
conv.encodeLinkSetup(setup, start + 2U + M17_SYNC_LENGTH_BYTES);
unsigned char temp[M17_FRAME_LENGTH_BYTES];
interleaver(start + 2U, temp);
decorrelator(temp, start + 2U);
writeQueueNet(start);
}
unsigned char data[M17_FRAME_LENGTH_BYTES + 2U];
data[0U] = TAG_DATA;
data[1U] = 0x00U;
// Generate the sync
CSync::addM17StreamSync(data + 2U);
m_netFrames++;
// Add the fragment LICH
unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
m_netLICH.getFragment(lich, m_netLICHn);
unsigned int frag1, frag2, frag3, frag4;
CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
// Add the Color Code and fragment number
frag4 |= (m_netLICHn & 0x07U) << 4;
frag4 |= (m_colorCode & 0x1FU) << 7;
// Add Golay to the LICH fragment here
unsigned int lich1 = CGolay24128::encode24128(frag1);
unsigned int lich2 = CGolay24128::encode24128(frag2);
unsigned int lich3 = CGolay24128::encode24128(frag3);
unsigned int lich4 = CGolay24128::encode24128(frag4);
CM17Utils::combineFragmentLICHFEC(lich1, lich2, lich3, lich4, data + 2U + M17_SYNC_LENGTH_BYTES);
// Add the FN and the data/audio
unsigned char payload[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
::memcpy(payload, netData + 28U, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES);
// Add the CRC
CM17CRC::encodeCRC(payload, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
// Add the Convolution FEC
CM17Convolution conv;
conv.encodeData(payload, data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES);
unsigned char temp[M17_FRAME_LENGTH_BYTES];
interleaver(data + 2U, temp);
decorrelator(temp, data + 2U);
writeQueueNet(data);
m_netLICHn++;
if (m_netLICHn >= 6U)
m_netLICHn = 0U;
// EOT handling
uint16_t fn = (netData[28U] << 8) + (netData[29U] << 0);
if ((fn & 0x8000U) == 0x8000U) {
std::string source = m_netLICH.getSource();
std::string dest = m_netLICH.getDest();
LogMessage("M17, received network end of transmission from %s to %s, %.1f seconds", source.c_str(), dest.c_str(), float(m_netFrames) / 25.0F);
writeEndNet();
}
}
void CM17Control::clock(unsigned int ms)
{
if (m_network != NULL)
writeNetwork();
m_rfTimeoutTimer.clock(ms);
m_netTimeoutTimer.clock(ms);
if (m_netState == RS_NET_AUDIO) {
m_networkWatchdog.clock(ms);
if (m_networkWatchdog.hasExpired()) {
LogMessage("M17, network watchdog has expired, %.1f seconds", float(m_netFrames) / 25.0F);
writeEndNet();
}
}
}
void CM17Control::writeQueueRF(const unsigned char *data)
{
assert(data != NULL);
if (m_netState != RS_NET_IDLE)
return;
if (m_rfTimeoutTimer.isRunning() && m_rfTimeoutTimer.hasExpired())
return;
unsigned char len = M17_FRAME_LENGTH_BYTES + 2U;
unsigned int space = m_queue.freeSpace();
if (space < (len + 1U)) {
LogError("M17, overflow in the M17 RF queue");
return;
}
m_queue.addData(&len, 1U);
m_queue.addData(data, len);
}
void CM17Control::writeQueueNet(const unsigned char *data)
{
assert(data != NULL);
if (m_netTimeoutTimer.isRunning() && m_netTimeoutTimer.hasExpired())
return;
unsigned char len = M17_FRAME_LENGTH_BYTES + 2U;
unsigned int space = m_queue.freeSpace();
if (space < (len + 1U)) {
LogError("M17, overflow in the M17 RF queue");
return;
}
m_queue.addData(&len, 1U);
m_queue.addData(data, len);
}
void CM17Control::writeNetwork(const unsigned char *data)
{
assert(data != NULL);
if (m_network == NULL)
return;
if (m_rfTimeoutTimer.isRunning() && m_rfTimeoutTimer.hasExpired())
return;
m_network->write(data);
}
void CM17Control::interleaver(const unsigned char* in, unsigned char* out) const
{
assert(in != NULL);
assert(out != NULL);
for (unsigned int i = 0U; i < (M17_FRAME_LENGTH_BITS - M17_SYNC_LENGTH_BITS); i++) {
unsigned int n1 = i + M17_SYNC_LENGTH_BITS;
bool b = READ_BIT(in, n1) != 0U;
unsigned int n2 = INTERLEAVER[i] + M17_SYNC_LENGTH_BITS;
WRITE_BIT(out, n2, b);
}
}
void CM17Control::decorrelator(const unsigned char* in, unsigned char* out) const
{
assert(in != NULL);
assert(out != NULL);
for (unsigned int i = M17_SYNC_LENGTH_BYTES; i < M17_FRAME_LENGTH_BYTES; i++) {
out[i] = in[i] ^ SCRAMBLER[i];
}
}
bool CM17Control::checkCallsign(const std::string& callsign) const
{
size_t len = m_callsign.size();
return m_callsign.compare(0U, len, callsign, 0U, len) == 0;
}
bool CM17Control::openFile()
{
if (m_fp != NULL)
return true;
time_t t;
::time(&t);
struct tm* tm = ::localtime(&t);
char name[100U];
::sprintf(name, "M17_%04d%02d%02d_%02d%02d%02d.ambe", tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
m_fp = ::fopen(name, "wb");
if (m_fp == NULL)
return false;
::fwrite("M17", 1U, 3U, m_fp);
return true;
}
bool CM17Control::writeFile(const unsigned char* data)
{
if (m_fp == NULL)
return false;
::fwrite(data, 1U, M17_FRAME_LENGTH_BYTES, m_fp);
return true;
}
void CM17Control::closeFile()
{
if (m_fp != NULL) {
::fclose(m_fp);
m_fp = NULL;
}
}
bool CM17Control::isBusy() const
{
return m_rfState != RS_RF_LISTENING || m_netState != RS_NET_IDLE;
}
void CM17Control::enable(bool enabled)
{
if (!enabled && m_enabled) {
m_queue.clear();
// Reset the RF section
m_rfState = RS_RF_LISTENING;
m_rfTimeoutTimer.stop();
// Reset the networking section
m_netState = RS_NET_IDLE;
m_netTimeoutTimer.stop();
m_networkWatchdog.stop();
m_packetTimer.stop();
}
m_enabled = enabled;
}
unsigned int CM17Control::countBits(unsigned char byte)
{
unsigned int count = 0U;
const unsigned char* p = &byte;
for (unsigned int i = 0U; i < 8U; i++) {
if (READ_BIT(p, i) != 0U)
count++;
}
return count;
}