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Merge pull request #422 from gatekeep/master

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Add support to decode, encode and process P25 TSDU data.
This commit is contained in:
Jonathan Naylor 2018-05-14 18:44:19 +01:00 committed by GitHub
parent 5c69f50455 074919ea5c
commit af63f8e8db
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 254 additions and 1 deletions
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91
P25Control.cpp
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -176,6 +177,9 @@ bool CP25Control::writeModem(unsigned char* data, unsigned int len)
case P25_DUID_PDU:
duid = P25_DUID_PDU;
break;
case P25_DUID_TSDU:
duid = P25_DUID_TSDU;
break;
default:
break;
}
@ -346,6 +350,85 @@ bool CP25Control::writeModem(unsigned char* data, unsigned int len)
return true;
}
} else if (duid == P25_DUID_TSDU) {
if (m_rfState != RS_RF_DATA) {
m_rfPDUCount = 0U;
m_rfPDUBits = 0U;
m_rfState = RS_RF_DATA;
m_rfDataFrames = 0U;
}
bool ret = m_rfData.decodeTSDU(data + 2U);
if (!ret) {
m_lastDUID = duid;
return false;
}
unsigned int srcId = m_rfData.getSrcId();
unsigned int dstId = m_rfData.getDstId();
unsigned char data[P25_TSDU_FRAME_LENGTH_BYTES + 2U];
switch (m_rfData.getLCF()) {
case P25_LCF_TSBK_CALL_ALERT:
LogMessage("P25, received RF TSDU transmission, CALL ALERT from %u to %u", srcId, dstId);
::memset(data + 2U, 0x00U, P25_TSDU_FRAME_LENGTH_BYTES);
// Regenerate Sync
CSync::addP25Sync(data + 2U);
// Regenerate NID
m_nid.encode(data + 2U, P25_DUID_TSDU);
// Regenerate TDULC Data
m_rfData.encodeTSDU(data + 2U);
// Add busy bits
addBusyBits(data + 2U, P25_TSDU_FRAME_LENGTH_BITS, true, false);
// Set first busy bits to 1,1
setBusyBits(data + 2U, P25_SS0_START, true, true);
if (m_duplex) {
data[0U] = TAG_DATA;
data[1U] = 0x00U;
writeQueueRF(data, P25_TSDU_FRAME_LENGTH_BYTES + 2U);
}
break;
case P25_LCF_TSBK_ACK_RSP_FNE:
LogMessage("P25, received RF TSDU transmission, ACK RESPONSE FNE from %u to %u", srcId, dstId);
::memset(data + 2U, 0x00U, P25_TSDU_FRAME_LENGTH_BYTES);
// Regenerate Sync
CSync::addP25Sync(data + 2U);
// Regenerate NID
m_nid.encode(data + 2U, P25_DUID_TSDU);
// Regenerate TDULC Data
m_rfData.encodeTSDU(data + 2U);
// Add busy bits
addBusyBits(data + 2U, P25_TSDU_FRAME_LENGTH_BITS, true, false);
// Set first busy bits to 1,1
setBusyBits(data + 2U, P25_SS0_START, true, true);
if (m_duplex) {
data[0U] = TAG_DATA;
data[1U] = 0x00U;
writeQueueRF(data, P25_TSDU_FRAME_LENGTH_BYTES + 2U);
}
break;
default:
LogMessage("P25, recieved RF TSDU transmission, unhandled LCF $%02X", m_rfData.getLCF());
break;
}
m_rfState = RS_RF_LISTENING;
return true;
} else if (duid == P25_DUID_TERM || duid == P25_DUID_TERM_LC) {
if (m_rfState == RS_RF_AUDIO) {
writeNetwork(m_rfLDU, m_lastDUID, true);
@ -693,6 +776,14 @@ void CP25Control::writeNetwork(const unsigned char *data, unsigned char type, bo
}
}
void CP25Control::setBusyBits(unsigned char* data, unsigned int ssOffset, bool b1, bool b2)
{
assert(data != NULL);
WRITE_BIT(data, ssOffset, b1);
WRITE_BIT(data, ssOffset + 1U, b2);
}
void CP25Control::addBusyBits(unsigned char* data, unsigned int length, bool b1, bool b2)
{
assert(data != NULL);

2
P25Control.h
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -94,6 +95,7 @@ private:
void writeNetwork(const unsigned char *data, unsigned char type, bool end);
void writeNetwork();
void setBusyBits(unsigned char* data, unsigned int ssOffset, bool b1, bool b2);
void addBusyBits(unsigned char* data, unsigned int length, bool b1, bool b2);
void checkNetLDU1();

125
P25Data.cpp
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2017 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -19,6 +20,7 @@
#include "P25Data.h"
#include "P25Defines.h"
#include "P25Utils.h"
#include "CRC.h"
#include "Hamming.h"
#include "Utils.h"
#include "Log.h"
@ -54,7 +56,8 @@ m_lcf(0x00U),
m_emergency(false),
m_srcId(0U),
m_dstId(0U),
m_rs241213()
m_rs241213(),
m_trellis()
{
m_mi = new unsigned char[P25_MI_LENGTH_BYTES];
}
@ -206,6 +209,116 @@ void CP25Data::encodeLDU2(unsigned char* data)
CP25Utils::encode(raw, data, 1356U, 1398U);
}
bool CP25Data::decodeTSDU(const unsigned char* data)
{
assert(data != NULL);
// deinterleave
unsigned char tsbk[12U];
unsigned char raw[25U];
CP25Utils::decode(data, raw, 114U, 318U);
// decode 1/2 rate Trellis & check CRC-CCITT 16
try {
bool ret = m_trellis.decode12(raw, tsbk);
if (ret)
ret = CCRC::checkCCITT162(tsbk, 12U);
if (!ret)
return false;
}
catch (...) {
CUtils::dump(2U, "P25, CRC failed with input data", tsbk, 12U);
return false;
}
m_lcf = tsbk[0U] & 0x3F;
m_mfId = tsbk[1U];
unsigned long long tsbkValue = 0U;
// combine bytes into rs value
tsbkValue = tsbk[2U];
tsbkValue = (tsbkValue << 8) + tsbk[3U];
tsbkValue = (tsbkValue << 8) + tsbk[4U];
tsbkValue = (tsbkValue << 8) + tsbk[5U];
tsbkValue = (tsbkValue << 8) + tsbk[6U];
tsbkValue = (tsbkValue << 8) + tsbk[7U];
tsbkValue = (tsbkValue << 8) + tsbk[8U];
tsbkValue = (tsbkValue << 8) + tsbk[9U];
switch (m_lcf) {
case P25_LCF_TSBK_CALL_ALERT:
m_dstId = (unsigned int)((tsbkValue >> 24) & 0xFFFFFFU); // Target Radio Address
m_srcId = (unsigned int)(tsbkValue & 0xFFFFFFU); // Source Radio Address
break;
case P25_LCF_TSBK_ACK_RSP_FNE:
m_serviceType = (unsigned char)((tsbkValue >> 56) & 0xFFU); // Service Type
m_dstId = (unsigned int)((tsbkValue >> 24) & 0xFFFFFFU); // Target Radio Address
m_srcId = (unsigned int)(tsbkValue & 0xFFFFFFU); // Source Radio Address
break;
default:
LogMessage("P25, unknown LCF value in TSDU - $%02X", m_lcf);
break;
}
return true;
}
void CP25Data::encodeTSDU(unsigned char* data)
{
assert(data != NULL);
unsigned char tsbk[12U];
::memset(tsbk, 0x00U, 12U);
unsigned long long tsbkValue = 0U;
tsbk[0U] = m_lcf;
tsbk[0U] |= 0x80;
tsbk[1U] = m_mfId;
switch (m_lcf) {
case P25_LCF_TSBK_CALL_ALERT:
tsbkValue = 0U;
tsbkValue = (tsbkValue << 16) + 0U;
tsbkValue = (tsbkValue << 24) + m_dstId; // Target Radio Address
tsbkValue = (tsbkValue << 24) + m_srcId; // Source Radio Address
break;
case P25_LCF_TSBK_ACK_RSP_FNE:
tsbkValue = 0U; // Additional Info. Flag
tsbkValue = (tsbkValue << 1) + 0U; // Extended Address Flag
tsbkValue = (tsbkValue << 16) + (m_serviceType & 0xFF); // Service Type
tsbkValue = (tsbkValue << 32) + m_dstId; // Target Radio Address
tsbkValue = (tsbkValue << 24) + m_srcId; // Source Radio Address
break;
default:
LogMessage("P25, unknown LCF value in TSDU - $%02X", m_lcf);
break;
}
// split rs value into bytes
tsbk[2U] = (unsigned char)((tsbkValue >> 56) & 0xFFU);
tsbk[3U] = (unsigned char)((tsbkValue >> 48) & 0xFFU);
tsbk[4U] = (unsigned char)((tsbkValue >> 40) & 0xFFU);
tsbk[5U] = (unsigned char)((tsbkValue >> 32) & 0xFFU);
tsbk[6U] = (unsigned char)((tsbkValue >> 24) & 0xFFU);
tsbk[7U] = (unsigned char)((tsbkValue >> 16) & 0xFFU);
tsbk[8U] = (unsigned char)((tsbkValue >> 8) & 0xFFU);
tsbk[9U] = (unsigned char)((tsbkValue >> 0) & 0xFFU);
// compute CRC-CCITT 16
CCRC::addCCITT162(tsbk, 12U);
unsigned char raw[25U];
::memset(raw, 0x00U, 25U);
// encode 1/2 rate Trellis
m_trellis.encode12(tsbk, raw);
// interleave
CP25Utils::encode(raw, data, 114U, 318U);
}
void CP25Data::setMI(const unsigned char* mi)
{
assert(mi != NULL);
@ -290,6 +403,16 @@ unsigned int CP25Data::getDstId() const
return m_dstId;
}
void CP25Data::setServiceType(unsigned char type)
{
m_serviceType = type;
}
unsigned char CP25Data::getServiceType() const
{
return m_serviceType;
}
void CP25Data::reset()
{
::memset(m_mi, 0x00U, P25_MI_LENGTH_BYTES);

10
P25Data.h
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2017 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -20,6 +21,7 @@
#define P25Data_H
#include "RS241213.h"
#include "P25Trellis.h"
class CP25Data {
public:
@ -33,6 +35,9 @@ public:
void encodeLDU2(unsigned char* data);
bool decodeTSDU(const unsigned char* data);
void encodeTSDU(unsigned char* data);
void setMI(const unsigned char* mi);
void getMI(unsigned char* mi) const;
@ -57,6 +62,9 @@ public:
void setDstId(unsigned int id);
unsigned int getDstId() const;
void setServiceType(unsigned char type);
unsigned char getServiceType() const;
void reset();
private:
@ -68,7 +76,9 @@ private:
bool m_emergency;
unsigned int m_srcId;
unsigned int m_dstId;
unsigned char m_serviceType;
CRS241213 m_rs241213;
CP25Trellis m_trellis;
void decodeLDUHamming(const unsigned char* raw, unsigned char* data);
void encodeLDUHamming(unsigned char* data, const unsigned char* raw);

8
P25Defines.h
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -31,6 +32,9 @@ const unsigned int P25_TERM_FRAME_LENGTH_BITS = P25_TERM_FRAME_LENGTH_BYTES * 8
const unsigned int P25_TERMLC_FRAME_LENGTH_BYTES = 54U;
const unsigned int P25_TERMLC_FRAME_LENGTH_BITS = P25_TERMLC_FRAME_LENGTH_BYTES * 8U;
const unsigned int P25_TSDU_FRAME_LENGTH_BYTES = 45U;
const unsigned int P25_TSDU_FRAME_LENGTH_BITS = P25_TSDU_FRAME_LENGTH_BYTES * 8U;
const unsigned int P25_SYNC_LENGTH_BYTES = 6U;
const unsigned int P25_SYNC_LENGTH_BITS = P25_SYNC_LENGTH_BYTES * 8U;
@ -54,6 +58,9 @@ const unsigned int P25_MI_LENGTH_BYTES = 9U;
const unsigned char P25_LCF_GROUP = 0x00U;
const unsigned char P25_LCF_PRIVATE = 0x03U;
const unsigned char P25_LCF_TSBK_CALL_ALERT = 0x1FU;
const unsigned char P25_LCF_TSBK_ACK_RSP_FNE = 0x20U;
const unsigned int P25_SS0_START = 70U;
const unsigned int P25_SS1_START = 71U;
const unsigned int P25_SS_INCREMENT = 72U;
@ -61,6 +68,7 @@ const unsigned int P25_SS_INCREMENT = 72U;
const unsigned char P25_DUID_HEADER = 0x00U;
const unsigned char P25_DUID_TERM = 0x03U;
const unsigned char P25_DUID_LDU1 = 0x05U;
const unsigned char P25_DUID_TSDU = 0x07U;
const unsigned char P25_DUID_LDU2 = 0x0AU;
const unsigned char P25_DUID_PDU = 0x0CU;
const unsigned char P25_DUID_TERM_LC = 0x0FU;

17
P25NID.cpp
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2018 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -72,6 +73,13 @@ m_pdu(NULL)
bch.encode(m_term);
m_term[7U] &= 0xFEU; // Clear the parity bit
m_tsdu = new unsigned char[P25_NID_LENGTH_BYTES];
m_tsdu[0U] = (nac >> 4) & 0xFFU;
m_tsdu[1U] = (nac << 4) & 0xF0U;
m_tsdu[1U] |= P25_DUID_TSDU;
bch.encode(m_tsdu);
m_tsdu[7U] &= 0xFEU; // Clear the parity bit
m_pdu = new unsigned char[P25_NID_LENGTH_BYTES];
m_pdu[0U] = (nac >> 4) & 0xFFU;
m_pdu[1U] = (nac << 4) & 0xF0U;
@ -127,6 +135,12 @@ bool CP25NID::decode(const unsigned char* data)
return true;
}
errs = CP25Utils::compare(nid, m_tsdu, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_TSDU;
return true;
}
errs = CP25Utils::compare(nid, m_pdu, P25_NID_LENGTH_BYTES);
if (errs < MAX_NID_ERRS) {
m_duid = P25_DUID_PDU;
@ -156,6 +170,9 @@ void CP25NID::encode(unsigned char* data, unsigned char duid) const
case P25_DUID_TERM_LC:
CP25Utils::encode(m_termlc, data, 48U, 114U);
break;
case P25_DUID_TSDU:
CP25Utils::encode(m_tsdu, data, 48U, 114U);
break;
case P25_DUID_PDU:
CP25Utils::encode(m_pdu, data, 48U, 114U);
break;

2
P25NID.h
View file

@ -1,5 +1,6 @@
/*
* Copyright (C) 2016,2018 by Jonathan Naylor G4KLX
* Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
*
* 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
@ -37,6 +38,7 @@ private:
unsigned char* m_ldu2;
unsigned char* m_termlc;
unsigned char* m_term;
unsigned char* m_tsdu;
unsigned char* m_pdu;
};