Mercurialmidi/djm-fix / file revision
summary | shortlog | changelog | graph | tags | bookmarks | branches | files | changeset | file | latest | revisions | annotate | diff | raw | help
DJMFix.cpp
author František Kučera <franta-hg@frantovo.cz>
Sat, 06 Sep 2025 23:49:23 +0200
branchv_0
changeset 22 de678a266ab8
parent 19 4ed672cecc25
permissions -rw-r--r--
improved sendKeepAlive logic 
     1 /**

     2  * DJM-Fix

     3  * Copyright © 2025 František Kučera (Frantovo.cz, GlobalCode.info)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, version 3 of the License.

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    16  */

    17 #include <iostream>

    18 #include <sstream>

    19 #include <iomanip>

    20 #include <thread>

    21 #include <mutex>

    22 #include <atomic>

    23 #include <chrono>

    24 #include <stdexcept>

    25 #include <vector>

    26 #include <regex>

    27 

    28 #include "DJMFix.h"

    29 #include "MessageCodec.h"

    30 

    31 namespace djmfix {

    32 

    33 using L = djmfix::logging::Level;

    34 using Bytes = std::vector<uint8_t>;

    35 namespace chro = std::chrono;

    36 

    37 class DJMFixImpl : public DJMFix {

    38 private:

    39 	MidiSender* midiSender;

    40 	djmfix::logging::Logger* logger;

    41 	MessageCodec codec;

    42 	const int keepAliveInterval = 200;

    43 	int keepAliveCounter = 0;

    44 	std::thread keepAliveThread;

    45 	std::recursive_mutex midiMutex;

    46 	std::atomic<bool> running{false};

    47 	std::atomic<bool> stopped{false};

    48 	std::atomic<bool> sendKeepAlive{false};

    49 	/**

    50 	 * Device (V10) may send multiple greeting messages.

    51 	 * It works even if we respond multiple times. But one response is enough.

    52 	 */

    53 	std::atomic<bool> greetingReceived{false};

    54 

    55 	Bytes seed0 = {0x68, 0x01, 0x31, 0xFB};

    56 	Bytes seed1 = {0x29, 0x00, 0x00, 0x00, 0x23, 0x48, 0x00, 0x00};

    57 	Bytes seed2;

    58 	Bytes seed3;

    59 

    60 	Bytes name1 = {0x50, 0x69, 0x6f, 0x6e, 0x65, 0x65, 0x72, 0x44, 0x4a};

    61 	Bytes name2 = {0x72, 0x65, 0x6b, 0x6f, 0x72, 0x64, 0x62, 0x6f, 0x78};

    62 

    63 	Bytes hash1;

    64 	Bytes hash2;

    65 

    66 	uint8_t model = 0x17;

    67 

    68 	void run() {

    69 		while (!stopped) {

    70 			logger->log(L::FINE, "DJMFixImpl::run()");

    71 			if (sendKeepAlive) {

    72 				send({

    73 					0xf0, 0x00, 0x40, 0x05,

    74 					0x00, 0x00, 0x00, model,

    75 					0x00, 0x50, 0x01, 0xf7

    76 				});

    77 				keepAliveCounter++;

    78 				if (keepAliveCounter % (60 * 1000 / keepAliveInterval) == 0)

    79 					logger->log(L::INFO,

    80 						"Still sending periodic keep-alive messages "

    81 						"(each " + std::to_string(keepAliveInterval) + " ms).");

    82 			}

    83 			std::this_thread::sleep_for(chro::milliseconds(keepAliveInterval));

    84 		}

    85 	}

    86 

    87 	void send(const Message& msg) {

    88 		logger->log(L::FINE, "<!-- Sent message: -->" + msg.toString());

    89 		send(codec.encode(msg));

    90 	}

    91 

    92 	void send(const MidiMessage& midiMessage) {

    93 		std::lock_guard<std::recursive_mutex> lock(midiMutex);

    94 		midiSender->send(midiMessage);

    95 	}

    96 

    97 	std::string toString(const Bytes& midiMessage) {

    98 		std::stringstream result;

    99 		for (uint8_t b : midiMessage)

   100 			result << std::hex << std::setw(2) << std::setfill('0') << (int) b;

   101 		return result.str();

   102 	}

   103 

   104 	Bytes normalize(const Bytes& data) {

   105 		if (data.size() % 2) throw std::invalid_argument(

   106 				"Data before normalization must have even number of bytes.");

   107 		Bytes result;

   108 		result.reserve(data.size() / 2);

   109 		for (size_t i = 0; i < data.size() / 2; i++) result.push_back(

   110 				(data[i * 2] & 0x0F) << 4 | (data[i * 2 + 1] & 0x0F));

   111 		return result;

   112 	}

   113 

   114 	Bytes denormalize(const Bytes& data) {

   115 		Bytes result;

   116 		result.reserve(data.size()*2);

   117 		for (size_t i = 0; i < data.size(); i++) {

   118 			result.push_back(data[i] >> 4);

   119 			result.push_back(data[i] & 0x0F);

   120 		}

   121 		return result;

   122 	}

   123 

   124 	uint32_t fnv32hash(const Bytes& buff) {

   125 		uint32_t hash = 0x811c9dc5;

   126 		for (uint8_t b : buff) hash = ((b^hash) * 0x1000193);

   127 		return hash;

   128 	}

   129 

   130 	Bytes toBytes(const uint32_t value) {

   131 		Bytes result;

   132 		result.reserve(4);

   133 		result.push_back(value >> 24);

   134 		result.push_back(value >> 16);

   135 		result.push_back(value >> 8);

   136 		result.push_back(value >> 0);

   137 		return result;

   138 	}

   139 

   140 	bool equals(Bytes a, Bytes b) {

   141 		if (a.size() != b.size()) return false;

   142 		for (size_t i = 0; i < a.size(); i++) if (a[i] != b[i]) return false;

   143 		return true;

   144 	}

   145 

   146 	template<typename T> std::vector<T> concat(

   147 			const std::vector<T>& a,

   148 			const std::vector<T>& b,

   149 			const std::vector<T>& c = {}) //

   150 	{

   151 		std::vector<T> result;

   152 		result.reserve(a.size() + b.size() + c.size());

   153 		for (size_t i = 0; i < a.size(); i++) result.push_back(a[i]);

   154 		for (size_t i = 0; i < b.size(); i++) result.push_back(b[i]);

   155 		for (size_t i = 0; i < c.size(); i++) result.push_back(c[i]);

   156 		return result;

   157 	}

   158 

   159 	template<typename T>

   160 	std::vector<T> xOR(const std::vector<T>& a, const std::vector<T>& b) {

   161 		if (a.size() != b.size()) throw std::invalid_argument(

   162 				"Both must be the same length when doing XOR.");

   163 		std::vector<T> result;

   164 		result.reserve(a.size());

   165 		for (size_t i = 0; i < a.size(); i++) result.push_back(a[i] ^ b[i]);

   166 		return result;

   167 	}

   168 

   169 public:

   170 

   171 	DJMFixImpl(djmfix::logging::Logger* logger)

   172 	: logger(logger ? logger : djmfix::logging::blackhole()) {

   173 	}

   174 

   175 	virtual ~DJMFixImpl() override {

   176 		logger->log(L::FINER, "~DJMFixImpl()");

   177 		if (running) stop();

   178 	}

   179 

   180 	void setDeviceName(std::string name) override {

   181 		logger->log(L::FINE, "DJMFixImpl::setDeviceName(" + name + ")");

   182 

   183 		std::regex djm250pattern("Pioneer DJ Corporation DJM-250MK2.*");

   184 		std::regex djm450pattern("Pioneer DJ Corporation DJM-450.*");

   185 

   186 		if (std::regex_match(name, djm250pattern)) {

   187 			// DJM-250MK2:

   188 			model = 0x17;

   189 			seed3 = {

   190 				0x59, 0xb5, 0x4b, 0xfe, 0xe4,

   191 				0x4a, 0x5a, 0xc8, 0xe4, 0xc5

   192 			};

   193 			logger->log(L::FINE, "Switched to DJM-250MK2 mode");

   194 		} else if (std::regex_match(name, djm450pattern)) {

   195 			// DJM-450:

   196 			// DJM-450 - not tested yet:

   197 			model = 0x13;

   198 			seed3 = {

   199 				0x99, 0xd5, 0x55, 0x43, 0x2c,

   200 				0x70, 0x53, 0x7a, 0x6f, 0x02

   201 			};

   202 			logger->log(L::FINE, "Switched to DJM-450 mode");

   203 		} else {

   204 			// DJM-V10:

   205 			model = 0x34;

   206 			seed3 = {

   207 				0x70, 0x01, 0x4d, 0x05, 0xbe,

   208 				0xf2, 0xe4, 0xde, 0x60, 0xd6

   209 			};

   210 			logger->log(L::FINE, "Switched to DJM-V10 mode");

   211 		}

   212 	}

   213 

   214 	void setMidiSender(MidiSender* midiSender) override {

   215 		logger->log(L::FINER, "DJMFixImpl::setMidiSender()");

   216 		this->midiSender = midiSender;

   217 	}

   218 

   219 	virtual void receive(const MidiMessage& msg) override {

   220 		// TODO: remove try/catch - there should be no unknown messages

   221 		try {

   222 			receive0(msg);

   223 		} catch (const std::exception& e) {

   224 			logger->log(L::SEVERE,

   225 					std::string("Message receiving failed: ") + e.what());

   226 		}

   227 	}

   228 

   229 	virtual void receive0(const MidiMessage& msg) {

   230 		logger->log(L::FINE, "Received a message: "

   231 				"size = " + std::to_string(msg.size()) + " "

   232 				"data = " + toString(msg));

   233 		std::lock_guard<std::recursive_mutex> lock(midiMutex);

   234 		Message msgIn = codec.decode(msg);

   235 

   236 		logger->log(L::FINE, "<!-- Received message: -->" + msgIn.toString());

   237 

   238 		if (msgIn.type == MessageType::D11_GREETING && !greetingReceived) {

   239 			logger->log(L::INFO, "Received greeting message.");

   240 			Message msgOut(MessageType::H12_SEED1, model,{

   241 				{FieldType::F01, name1},

   242 				{FieldType::F02, name2},

   243 				{FieldType::F03, denormalize(seed1)}

   244 			});

   245 			send(msgOut);

   246 			greetingReceived = true;

   247 			logger->log(L::INFO, "Sent message with seed1.");

   248 		} else if (msgIn.type == MessageType::D13_HASH1_SEED2) {

   249 			std::vector<Field> hash1F = msgIn.findFields(FieldType::F04);

   250 			std::vector<Field> seed2F = msgIn.findFields(FieldType::F03);

   251 

   252 			if (hash1F.empty()) throw std::logic_error("hash1 not found");

   253 			if (seed2F.empty()) throw std::logic_error("seed2 not found");

   254 

   255 			hash1 = normalize(hash1F[0].data);

   256 			seed2 = normalize(seed2F[0].data);

   257 

   258 			logger->log(L::INFO, "Received message with "

   259 					"hash1 = " + toString(hash1) + " and "

   260 					"seed2 = " + toString(seed2));

   261 

   262 			Bytes hash1check =

   263 					toBytes(fnv32hash(concat(seed1, xOR(seed0, seed2))));

   264 

   265 			if (equals(hash1, hash1check)) {

   266 				logger->log(L::INFO, "Verification of hash1 was successful.");

   267 				hash2 = toBytes(fnv32hash(concat(seed2, xOR(seed0, seed2))));

   268 

   269 				Message msgOut(MessageType::H14_HASH2, model,{

   270 					{FieldType::F01, name1},

   271 					{FieldType::F02, name2},

   272 					{FieldType::F04, denormalize(hash2)},

   273 					{FieldType::F05, denormalize(seed3)}

   274 				});

   275 				send(msgOut);

   276 				logger->log(L::INFO, "Sent message with hash2.");

   277 			} else {

   278 				std::stringstream logMessage;

   279 				logMessage

   280 						<< "Verification of hash1 failed: "

   281 						<< " midiMessage = " << toString(msg)

   282 						<< " seed0 = " << toString(seed0)

   283 						<< " seed1 = " << toString(seed1)

   284 						<< " seed2 = " << toString(seed2)

   285 						<< " hash1 = " << toString(hash1)

   286 						<< " hash1check = " << toString(hash1check);

   287 				logger->log(L::SEVERE, logMessage.str());

   288 				// TODO: graceful death

   289 			}

   290 		} else if (msgIn.type == MessageType::D15_CONFIRMATION) {

   291 			sendKeepAlive = true;

   292 			logger->log(L::INFO, "Received acknowledgment message. "

   293 					"Started sending keep-alive messages. "

   294 					"LINE/PHONO channels should work now.");

   295 		} else {

   296 			logger->log(L::SEVERE, "Received unexpected message type.");

   297 		}

   298 

   299 	}

   300 

   301 	void start() override {

   302 		logger->log(L::FINE, "DJMFixImpl::start()");

   303 		if (midiSender == nullptr)

   304 			throw std::logic_error("Need a midiSender when starting DJMFix");

   305 

   306 		send({

   307 			0xf0, 0x00, 0x40, 0x05,

   308 			0x00, 0x00, 0x00, model,

   309 			0x00, 0x50, 0x01, 0xf7

   310 		});

   311 

   312 		// TODO: check whether this second message is neccessary for V10:

   313 		send({

   314 			0xf0, 0x00, 0x40, 0x05,

   315 			0x00, 0x00, 0x00, model,

   316 			0x00, 0x03, 0x01, 0xf7

   317 		});

   318 		logger->log(L::INFO, "Sent greeting message.");

   319 

   320 		keepAliveThread = std::thread(&DJMFixImpl::run, this);

   321 		running = true;

   322 

   323 	}

   324 

   325 	void stop() override {

   326 		stopped = true;

   327 		keepAliveThread.join();

   328 		running = false;

   329 		logger->log(L::FINE, "DJMFixImpl::stop()");

   330 	}

   331 };

   332 

   333 DJMFix* create(djmfix::logging::Logger* logger) {

   334 	return new DJMFixImpl(logger);

   335 }

   336 

   337 }
midi/djm-fix