You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
155 lines
4.4 KiB
155 lines
4.4 KiB
/*
|
|
* Copyright (C) 2010,2012,2018 by Jonathan Naylor G4KLX
|
|
* Copyright (C) 2021-2022 by Geoffrey Merck F4FXL / KC3FRA
|
|
*
|
|
* 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 <cstring>
|
|
#include <cassert>
|
|
#include <boost/algorithm/string.hpp>
|
|
#include <vector>
|
|
#include <algorithm>
|
|
#include <cstdlib>
|
|
|
|
#include "RSMS1AMessageCollector.h"
|
|
#include "StringUtils.h"
|
|
#include "Log.h"
|
|
#include "Utils.h"
|
|
#include "APRSUtils.h"
|
|
|
|
|
|
const unsigned int APRS_CSUM_LENGTH = 4U;
|
|
|
|
CRSMS1AMessageCollector::CRSMS1AMessageCollector() :
|
|
CSentenceCollector(SLOW_DATA_TYPE_GPS, "$$Msg", '\x0D')
|
|
{
|
|
|
|
}
|
|
|
|
bool CRSMS1AMessageCollector::isValidSentence(const std::string& sentence)
|
|
{
|
|
return isValidMsg(sentence);
|
|
}
|
|
|
|
bool CRSMS1AMessageCollector::isValidMsg(const std::string& msg)
|
|
{
|
|
if(msg.empty() || !boost::starts_with(msg, "$$Msg"))
|
|
return false;
|
|
|
|
// CUtils::dump("RS-MS1A:", (unsigned char *)msg.c_str(), msg.length());
|
|
std::vector<std::string> splits;
|
|
boost::split(splits, msg, boost::is_any_of(","));
|
|
|
|
bool ret = splits.size() >= 4
|
|
&& !splits[1].empty()
|
|
&& !splits[2].empty();
|
|
return ret;
|
|
|
|
//TODO 2022-01-01 figure out what the heck it is about thic strange CRCs
|
|
|
|
// CUtils::dump("RS-MS1A:", (unsigned char *)gpsa.c_str(), gpsa.length() + 1U);
|
|
// CLog::logDebug("RS-MS1A: %s", gpsa.c_str());
|
|
|
|
// auto thirdCommaPos = CStringUtils::find_nth(gpsa, 0U, ',', 3);
|
|
// auto csum = calcCRC(gpsa, thirdCommaPos + 6 + 1, gpsa.length() - thirdCommaPos - 2U - 6U);
|
|
// auto csumStr = CStringUtils::string_format("%06X", csum);
|
|
// CLog::logDebug("RS-MS1A CRC: %s", csumStr.c_str());
|
|
|
|
// auto expectedCsum = gpsa.substr(5U, APRS_CSUM_LENGTH);
|
|
// bool res = ::strcasecmp(csumStr.c_str(), expectedCsum.c_str()) == 0;
|
|
// return res;
|
|
}
|
|
|
|
unsigned int CRSMS1AMessageCollector::calcCRC(const std::string& gpsa, unsigned int start, unsigned int length)
|
|
{
|
|
unsigned int icomcrc = 0xFFFFU;
|
|
auto end = start + length;
|
|
if(end > gpsa.length()) {
|
|
end = gpsa.length();
|
|
}
|
|
|
|
for (unsigned int j = start; j < end; j++) {
|
|
unsigned char ch = (unsigned char)gpsa[j];
|
|
|
|
for (unsigned int i = 0U; i < 8U; i++) {
|
|
bool xorflag = (((icomcrc ^ ch) & 0x01U) == 0x01U);
|
|
|
|
icomcrc >>= 1;
|
|
|
|
if (xorflag)
|
|
icomcrc ^= 0x8408U;
|
|
|
|
ch >>= 1;
|
|
}
|
|
}
|
|
|
|
return ~icomcrc & 0xFFFFU;
|
|
}
|
|
|
|
unsigned int CRSMS1AMessageCollector::getDataInt(unsigned char * data, unsigned int length)
|
|
{
|
|
if(data == nullptr || length == 0U || getSentence().empty())
|
|
return 0U;
|
|
|
|
auto sentence = getSentence();
|
|
|
|
std::vector<std::string> splits;
|
|
boost::split(splits, sentence, boost::is_any_of(","));
|
|
|
|
bool ret = splits.size() >= 4
|
|
&& !splits[1].empty()
|
|
&& !splits[2].empty();
|
|
if(!ret) {
|
|
return 0U;
|
|
}
|
|
|
|
auto sender = splits[1];
|
|
auto recipient = CUtils::ToUpper(splits[2]);
|
|
|
|
for(unsigned int i = 0;i < 3; i++) {
|
|
splits.erase(splits.begin());
|
|
}
|
|
|
|
auto message = boost::join(splits, ",");
|
|
if(message.length() > 6)
|
|
message = message.substr(6);
|
|
|
|
auto seqNum = rand() % 0xFFFFFU;
|
|
|
|
CAPRSUtils::dstarCallsignToAPRS(sender);
|
|
CAPRSUtils::dstarCallsignToAPRS(recipient);
|
|
recipient.resize(9, ' ');
|
|
message.resize(std::max<int>(0 , ((int)message.length()) - 2));
|
|
|
|
//unescape commas in message body
|
|
boost::replace_all(message, "o,", ",");
|
|
|
|
auto aprsFrame = CStringUtils::string_format("%s-5>APDPRS,DSTAR*::%s:%s{%05X\r\n", sender.c_str(), recipient.c_str(), message.c_str(), seqNum);
|
|
|
|
auto aprsFrameLen = aprsFrame.length();
|
|
|
|
if(length < aprsFrameLen) {
|
|
CLog::logDebug("Not enough space to copy GPS-A APRS frame");
|
|
return 0U;
|
|
}
|
|
|
|
for(unsigned int i = 0U; i < aprsFrameLen; i++){
|
|
data[i] = aprsFrame[i];
|
|
}
|
|
|
|
return aprsFrameLen;
|
|
} |