MQTT
An API for using MQTT over multiple transports
Dependencies: FP MQTTPacket
Dependents: Cellular_HelloMQTT IoTStarterKit GSwifiInterface_HelloMQTT IBMIoTClientEthernetExample ... more
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MQTTClient.h
00001 /******************************************************************************* 00002 * Copyright (c) 2014, 2017 IBM Corp. 00003 * 00004 * All rights reserved. This program and the accompanying materials 00005 * are made available under the terms of the Eclipse Public License v1.0 00006 * and Eclipse Distribution License v1.0 which accompany this distribution. 00007 * 00008 * The Eclipse Public License is available at 00009 * http://www.eclipse.org/legal/epl-v10.html 00010 * and the Eclipse Distribution License is available at 00011 * http://www.eclipse.org/org/documents/edl-v10.php. 00012 * 00013 * Contributors: 00014 * Ian Craggs - initial API and implementation and/or initial documentation 00015 * Ian Craggs - fix for bug 458512 - QoS 2 messages 00016 * Ian Craggs - fix for bug 460389 - send loop uses wrong length 00017 * Ian Craggs - fix for bug 464169 - clearing subscriptions 00018 * Ian Craggs - fix for bug 464551 - enums and ints can be different size 00019 * Mark Sonnentag - fix for bug 475204 - inefficient instantiation of Timer 00020 * Ian Craggs - fix for bug 475749 - packetid modified twice 00021 * Ian Craggs - add ability to set message handler separately #6 00022 *******************************************************************************/ 00023 00024 #if !defined(MQTTCLIENT_H) 00025 #define MQTTCLIENT_H 00026 00027 #include "FP.h" 00028 #include "MQTTPacket.h" 00029 #include <stdio.h> 00030 #include "MQTTLogging.h" 00031 00032 #if !defined(MQTTCLIENT_QOS1) 00033 #define MQTTCLIENT_QOS1 1 00034 #endif 00035 #if !defined(MQTTCLIENT_QOS2) 00036 #define MQTTCLIENT_QOS2 0 00037 #endif 00038 00039 namespace MQTT 00040 { 00041 00042 00043 enum QoS { QOS0, QOS1, QOS2 }; 00044 00045 // all failure return codes must be negative 00046 enum returnCode { BUFFER_OVERFLOW = -2, FAILURE = -1, SUCCESS = 0 }; 00047 00048 00049 struct Message 00050 { 00051 enum QoS qos; 00052 bool retained; 00053 bool dup; 00054 unsigned short id; 00055 void *payload; 00056 size_t payloadlen; 00057 }; 00058 00059 00060 struct MessageData 00061 { 00062 MessageData(MQTTString &aTopicName, struct Message &aMessage) : message(aMessage), topicName(aTopicName) 00063 { } 00064 00065 struct Message &message; 00066 MQTTString &topicName; 00067 }; 00068 00069 00070 struct connackData 00071 { 00072 int rc; 00073 bool sessionPresent; 00074 }; 00075 00076 00077 struct subackData 00078 { 00079 int grantedQoS; 00080 }; 00081 00082 00083 class PacketId 00084 { 00085 public: 00086 PacketId() 00087 { 00088 next = 0; 00089 } 00090 00091 int getNext() 00092 { 00093 return next = (next == MAX_PACKET_ID) ? 1 : next + 1; 00094 } 00095 00096 private: 00097 static const int MAX_PACKET_ID = 65535; 00098 int next; 00099 }; 00100 00101 00102 /** 00103 * @class Client 00104 * @brief blocking, non-threaded MQTT client API 00105 * 00106 * This version of the API blocks on all method calls, until they are complete. This means that only one 00107 * MQTT request can be in process at any one time. 00108 * @param Network a network class which supports send, receive 00109 * @param Timer a timer class with the methods: 00110 */ 00111 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE = 100, int MAX_MESSAGE_HANDLERS = 5> 00112 class Client 00113 { 00114 00115 public: 00116 00117 typedef void (*messageHandler)(MessageData&); 00118 00119 /** Construct the client 00120 * @param network - pointer to an instance of the Network class - must be connected to the endpoint 00121 * before calling MQTT connect 00122 * @param limits an instance of the Limit class - to alter limits as required 00123 */ 00124 Client(Network& network, unsigned int command_timeout_ms = 30000); 00125 00126 /** Set the default message handling callback - used for any message which does not match a subscription message handler 00127 * @param mh - pointer to the callback function. Set to 0 to remove. 00128 */ 00129 void setDefaultMessageHandler(messageHandler mh) 00130 { 00131 if (mh != 0) 00132 defaultMessageHandler.attach(mh); 00133 else 00134 defaultMessageHandler.detach(); 00135 } 00136 00137 /** Set a message handling callback. This can be used outside of the the subscribe method. 00138 * @param topicFilter - a topic pattern which can include wildcards 00139 * @param mh - pointer to the callback function. If 0, removes the callback if any 00140 */ 00141 int setMessageHandler(const char* topicFilter, messageHandler mh); 00142 00143 /** MQTT Connect - send an MQTT connect packet down the network and wait for a Connack 00144 * The nework object must be connected to the network endpoint before calling this 00145 * Default connect options are used 00146 * @return success code - 00147 */ 00148 int connect(); 00149 00150 /** MQTT Connect - send an MQTT connect packet down the network and wait for a Connack 00151 * The nework object must be connected to the network endpoint before calling this 00152 * @param options - connect options 00153 * @return success code - 00154 */ 00155 int connect(MQTTPacket_connectData& options); 00156 00157 /** MQTT Connect - send an MQTT connect packet down the network and wait for a Connack 00158 * The nework object must be connected to the network endpoint before calling this 00159 * @param options - connect options 00160 * @param connackData - connack data to be returned 00161 * @return success code - 00162 */ 00163 int connect(MQTTPacket_connectData& options, connackData& data); 00164 00165 /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs 00166 * @param topic - the topic to publish to 00167 * @param message - the message to send 00168 * @return success code - 00169 */ 00170 int publish(const char* topicName, Message& message); 00171 00172 /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs 00173 * @param topic - the topic to publish to 00174 * @param payload - the data to send 00175 * @param payloadlen - the length of the data 00176 * @param qos - the QoS to send the publish at 00177 * @param retained - whether the message should be retained 00178 * @return success code - 00179 */ 00180 int publish(const char* topicName, void* payload, size_t payloadlen, enum QoS qos = QOS0, bool retained = false); 00181 00182 /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs 00183 * @param topic - the topic to publish to 00184 * @param payload - the data to send 00185 * @param payloadlen - the length of the data 00186 * @param id - the packet id used - returned 00187 * @param qos - the QoS to send the publish at 00188 * @param retained - whether the message should be retained 00189 * @return success code - 00190 */ 00191 int publish(const char* topicName, void* payload, size_t payloadlen, unsigned short& id, enum QoS qos = QOS1, bool retained = false); 00192 00193 /** MQTT Subscribe - send an MQTT subscribe packet and wait for the suback 00194 * @param topicFilter - a topic pattern which can include wildcards 00195 * @param qos - the MQTT QoS to subscribe at 00196 * @param mh - the callback function to be invoked when a message is received for this subscription 00197 * @return success code - 00198 */ 00199 int subscribe(const char* topicFilter, enum QoS qos, messageHandler mh); 00200 00201 /** MQTT Subscribe - send an MQTT subscribe packet and wait for the suback 00202 * @param topicFilter - a topic pattern which can include wildcards 00203 * @param qos - the MQTT QoS to subscribe at© 00204 * @param mh - the callback function to be invoked when a message is received for this subscription 00205 * @param 00206 * @return success code - 00207 */ 00208 int subscribe(const char* topicFilter, enum QoS qos, messageHandler mh, subackData &data); 00209 00210 /** MQTT Unsubscribe - send an MQTT unsubscribe packet and wait for the unsuback 00211 * @param topicFilter - a topic pattern which can include wildcards 00212 * @return success code - 00213 */ 00214 int unsubscribe(const char* topicFilter); 00215 00216 /** MQTT Disconnect - send an MQTT disconnect packet, and clean up any state 00217 * @return success code - 00218 */ 00219 int disconnect(); 00220 00221 /** A call to this API must be made within the keepAlive interval to keep the MQTT connection alive 00222 * yield can be called if no other MQTT operation is needed. This will also allow messages to be 00223 * received. 00224 * @param timeout_ms the time to wait, in milliseconds 00225 * @return success code - on failure, this means the client has disconnected 00226 */ 00227 int yield(unsigned long timeout_ms = 1000L); 00228 00229 /** Is the client connected? 00230 * @return flag - is the client connected or not? 00231 */ 00232 bool isConnected() 00233 { 00234 return isconnected; 00235 } 00236 00237 private: 00238 00239 void closeSession(); 00240 void cleanSession(); 00241 int cycle(Timer& timer); 00242 int waitfor(int packet_type, Timer& timer); 00243 int keepalive(); 00244 int publish(int len, Timer& timer, enum QoS qos); 00245 00246 int decodePacket(int* value, int timeout); 00247 int readPacket(Timer& timer); 00248 int sendPacket(int length, Timer& timer); 00249 int deliverMessage(MQTTString& topicName, Message& message); 00250 bool isTopicMatched(char* topicFilter, MQTTString& topicName); 00251 00252 Network& ipstack; 00253 unsigned long command_timeout_ms; 00254 00255 unsigned char sendbuf[MAX_MQTT_PACKET_SIZE]; 00256 unsigned char readbuf[MAX_MQTT_PACKET_SIZE]; 00257 00258 Timer last_sent, last_received; 00259 unsigned int keepAliveInterval; 00260 bool ping_outstanding; 00261 bool cleansession; 00262 00263 PacketId packetid; 00264 00265 struct MessageHandlers 00266 { 00267 const char* topicFilter; 00268 FP<void, MessageData&> fp; 00269 } messageHandlers[MAX_MESSAGE_HANDLERS]; // Message handlers are indexed by subscription topic 00270 00271 FP<void, MessageData&> defaultMessageHandler; 00272 00273 bool isconnected; 00274 00275 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 00276 unsigned char pubbuf[MAX_MQTT_PACKET_SIZE]; // store the last publish for sending on reconnect 00277 int inflightLen; 00278 unsigned short inflightMsgid; 00279 enum QoS inflightQoS; 00280 #endif 00281 00282 #if MQTTCLIENT_QOS2 00283 bool pubrel; 00284 #if !defined(MAX_INCOMING_QOS2_MESSAGES) 00285 #define MAX_INCOMING_QOS2_MESSAGES 10 00286 #endif 00287 unsigned short incomingQoS2messages[MAX_INCOMING_QOS2_MESSAGES]; 00288 bool isQoS2msgidFree(unsigned short id); 00289 bool useQoS2msgid(unsigned short id); 00290 void freeQoS2msgid(unsigned short id); 00291 #endif 00292 00293 }; 00294 00295 } 00296 00297 00298 template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS> 00299 void MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::cleanSession() 00300 { 00301 for (int i = 0; i < MAX_MESSAGE_HANDLERS; ++i) 00302 messageHandlers[i].topicFilter = 0; 00303 00304 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 00305 inflightMsgid = 0; 00306 inflightQoS = QOS0; 00307 #endif 00308 00309 #if MQTTCLIENT_QOS2 00310 pubrel = false; 00311 for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i) 00312 incomingQoS2messages[i] = 0; 00313 #endif 00314 } 00315 00316 00317 template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS> 00318 void MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::closeSession() 00319 { 00320 ping_outstanding = false; 00321 isconnected = false; 00322 if (cleansession) 00323 cleanSession(); 00324 } 00325 00326 00327 template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS> 00328 MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::Client(Network& network, unsigned int command_timeout_ms) : ipstack(network), packetid() 00329 { 00330 this->command_timeout_ms = command_timeout_ms; 00331 cleansession = true; 00332 closeSession(); 00333 } 00334 00335 00336 #if MQTTCLIENT_QOS2 00337 template<class Network, class Timer, int a, int b> 00338 bool MQTT::Client<Network, Timer, a, b>::isQoS2msgidFree(unsigned short id) 00339 { 00340 for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i) 00341 { 00342 if (incomingQoS2messages[i] == id) 00343 return false; 00344 } 00345 return true; 00346 } 00347 00348 00349 template<class Network, class Timer, int a, int b> 00350 bool MQTT::Client<Network, Timer, a, b>::useQoS2msgid(unsigned short id) 00351 { 00352 for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i) 00353 { 00354 if (incomingQoS2messages[i] == 0) 00355 { 00356 incomingQoS2messages[i] = id; 00357 return true; 00358 } 00359 } 00360 return false; 00361 } 00362 00363 00364 template<class Network, class Timer, int a, int b> 00365 void MQTT::Client<Network, Timer, a, b>::freeQoS2msgid(unsigned short id) 00366 { 00367 for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i) 00368 { 00369 if (incomingQoS2messages[i] == id) 00370 { 00371 incomingQoS2messages[i] = 0; 00372 return; 00373 } 00374 } 00375 } 00376 #endif 00377 00378 00379 template<class Network, class Timer, int a, int b> 00380 int MQTT::Client<Network, Timer, a, b>::sendPacket(int length, Timer& timer) 00381 { 00382 int rc = FAILURE, 00383 sent = 0; 00384 00385 while (sent < length) 00386 { 00387 rc = ipstack.write(&sendbuf[sent], length - sent, timer.left_ms()); 00388 if (rc < 0) // there was an error writing the data 00389 break; 00390 sent += rc; 00391 if (timer.expired()) // only check expiry after at least one attempt to write 00392 break; 00393 } 00394 if (sent == length) 00395 { 00396 if (this->keepAliveInterval > 0) 00397 last_sent.countdown(this->keepAliveInterval); // record the fact that we have successfully sent the packet 00398 rc = SUCCESS; 00399 } 00400 else 00401 rc = FAILURE; 00402 00403 #if defined(MQTT_DEBUG) 00404 char printbuf[150]; 00405 DEBUG("Rc %d from sending packet %s\r\n", rc, 00406 MQTTFormat_toServerString(printbuf, sizeof(printbuf), sendbuf, length)); 00407 #endif 00408 return rc; 00409 } 00410 00411 00412 template<class Network, class Timer, int a, int b> 00413 int MQTT::Client<Network, Timer, a, b>::decodePacket(int* value, int timeout) 00414 { 00415 unsigned char c; 00416 int multiplier = 1; 00417 int len = 0; 00418 const int MAX_NO_OF_REMAINING_LENGTH_BYTES = 4; 00419 00420 *value = 0; 00421 do 00422 { 00423 int rc = MQTTPACKET_READ_ERROR; 00424 00425 if (++len > MAX_NO_OF_REMAINING_LENGTH_BYTES) 00426 { 00427 rc = MQTTPACKET_READ_ERROR; /* bad data */ 00428 goto exit; 00429 } 00430 rc = ipstack.read(&c, 1, timeout); 00431 if (rc != 1) 00432 goto exit; 00433 *value += (c & 127) * multiplier; 00434 multiplier *= 128; 00435 } while ((c & 128) != 0); 00436 exit: 00437 return len; 00438 } 00439 00440 00441 /** 00442 * If any read fails in this method, then we should disconnect from the network, as on reconnect 00443 * the packets can be retried. 00444 * @param timeout the max time to wait for the packet read to complete, in milliseconds 00445 * @return the MQTT packet type, 0 if none, -1 if error 00446 */ 00447 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00448 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::readPacket(Timer& timer) 00449 { 00450 int rc = FAILURE; 00451 MQTTHeader header = {0}; 00452 int len = 0; 00453 int rem_len = 0; 00454 00455 /* 1. read the header byte. This has the packet type in it */ 00456 rc = ipstack.read(readbuf, 1, timer.left_ms()); 00457 if (rc != 1) 00458 goto exit; 00459 00460 len = 1; 00461 /* 2. read the remaining length. This is variable in itself */ 00462 decodePacket(&rem_len, timer.left_ms()); 00463 len += MQTTPacket_encode(readbuf + 1, rem_len); /* put the original remaining length into the buffer */ 00464 00465 if (rem_len > (MAX_MQTT_PACKET_SIZE - len)) 00466 { 00467 rc = BUFFER_OVERFLOW; 00468 goto exit; 00469 } 00470 00471 /* 3. read the rest of the buffer using a callback to supply the rest of the data */ 00472 if (rem_len > 0 && (ipstack.read(readbuf + len, rem_len, timer.left_ms()) != rem_len)) 00473 goto exit; 00474 00475 header.byte = readbuf[0]; 00476 rc = header.bits.type; 00477 if (this->keepAliveInterval > 0) 00478 last_received.countdown(this->keepAliveInterval); // record the fact that we have successfully received a packet 00479 exit: 00480 00481 #if defined(MQTT_DEBUG) 00482 if (rc >= 0) 00483 { 00484 char printbuf[50]; 00485 DEBUG("Rc %d receiving packet %s\r\n", rc, 00486 MQTTFormat_toClientString(printbuf, sizeof(printbuf), readbuf, len)); 00487 } 00488 #endif 00489 return rc; 00490 } 00491 00492 00493 // assume topic filter and name is in correct format 00494 // # can only be at end 00495 // + and # can only be next to separator 00496 template<class Network, class Timer, int a, int b> 00497 bool MQTT::Client<Network, Timer, a, b>::isTopicMatched(char* topicFilter, MQTTString& topicName) 00498 { 00499 char* curf = topicFilter; 00500 char* curn = topicName.lenstring.data; 00501 char* curn_end = curn + topicName.lenstring.len; 00502 00503 while (*curf && curn < curn_end) 00504 { 00505 if (*curn == '/' && *curf != '/') 00506 break; 00507 if (*curf != '+' && *curf != '#' && *curf != *curn) 00508 break; 00509 if (*curf == '+') 00510 { // skip until we meet the next separator, or end of string 00511 char* nextpos = curn + 1; 00512 while (nextpos < curn_end && *nextpos != '/') 00513 nextpos = ++curn + 1; 00514 } 00515 else if (*curf == '#') 00516 curn = curn_end - 1; // skip until end of string 00517 curf++; 00518 curn++; 00519 }; 00520 00521 return (curn == curn_end) && (*curf == '\0'); 00522 } 00523 00524 00525 00526 template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS> 00527 int MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::deliverMessage(MQTTString& topicName, Message& message) 00528 { 00529 int rc = FAILURE; 00530 00531 // we have to find the right message handler - indexed by topic 00532 for (int i = 0; i < MAX_MESSAGE_HANDLERS; ++i) 00533 { 00534 if (messageHandlers[i].topicFilter != 0 && (MQTTPacket_equals(&topicName, (char*)messageHandlers[i].topicFilter) || 00535 isTopicMatched((char*)messageHandlers[i].topicFilter, topicName))) 00536 { 00537 if (messageHandlers[i].fp.attached()) 00538 { 00539 MessageData md(topicName, message); 00540 messageHandlers[i].fp(md); 00541 rc = SUCCESS; 00542 } 00543 } 00544 } 00545 00546 if (rc == FAILURE && defaultMessageHandler.attached()) 00547 { 00548 MessageData md(topicName, message); 00549 defaultMessageHandler(md); 00550 rc = SUCCESS; 00551 } 00552 00553 return rc; 00554 } 00555 00556 00557 00558 template<class Network, class Timer, int a, int b> 00559 int MQTT::Client<Network, Timer, a, b>::yield(unsigned long timeout_ms) 00560 { 00561 int rc = SUCCESS; 00562 Timer timer; 00563 00564 timer.countdown_ms(timeout_ms); 00565 while (!timer.expired()) 00566 { 00567 if (cycle(timer) < 0) 00568 { 00569 rc = FAILURE; 00570 break; 00571 } 00572 } 00573 00574 return rc; 00575 } 00576 00577 00578 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00579 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::cycle(Timer& timer) 00580 { 00581 // get one piece of work off the wire and one pass through 00582 int len = 0, 00583 rc = SUCCESS; 00584 00585 int packet_type = readPacket(timer); // read the socket, see what work is due 00586 00587 switch (packet_type) 00588 { 00589 default: 00590 // no more data to read, unrecoverable. Or read packet fails due to unexpected network error 00591 rc = packet_type; 00592 goto exit; 00593 case 0: // timed out reading packet 00594 break; 00595 case CONNACK: 00596 case PUBACK: 00597 case SUBACK: 00598 break; 00599 case PUBLISH: 00600 { 00601 MQTTString topicName = MQTTString_initializer; 00602 Message msg; 00603 int intQoS; 00604 msg.payloadlen = 0; /* this is a size_t, but deserialize publish sets this as int */ 00605 if (MQTTDeserialize_publish((unsigned char*)&msg.dup, &intQoS, (unsigned char*)&msg.retained, (unsigned short*)&msg.id, &topicName, 00606 (unsigned char**)&msg.payload, (int*)&msg.payloadlen, readbuf, MAX_MQTT_PACKET_SIZE) != 1) 00607 goto exit; 00608 msg.qos = (enum QoS)intQoS; 00609 #if MQTTCLIENT_QOS2 00610 if (msg.qos != QOS2) 00611 #endif 00612 deliverMessage(topicName, msg); 00613 #if MQTTCLIENT_QOS2 00614 else if (isQoS2msgidFree(msg.id)) 00615 { 00616 if (useQoS2msgid(msg.id)) 00617 deliverMessage(topicName, msg); 00618 else 00619 WARN("Maximum number of incoming QoS2 messages exceeded"); 00620 } 00621 #endif 00622 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 00623 if (msg.qos != QOS0) 00624 { 00625 if (msg.qos == QOS1) 00626 len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBACK, 0, msg.id); 00627 else if (msg.qos == QOS2) 00628 len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBREC, 0, msg.id); 00629 if (len <= 0) 00630 rc = FAILURE; 00631 else 00632 rc = sendPacket(len, timer); 00633 if (rc == FAILURE) 00634 goto exit; // there was a problem 00635 } 00636 break; 00637 #endif 00638 } 00639 #if MQTTCLIENT_QOS2 00640 case PUBREC: 00641 case PUBREL: 00642 unsigned short mypacketid; 00643 unsigned char dup, type; 00644 if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1) 00645 rc = FAILURE; 00646 else if ((len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, 00647 (packet_type == PUBREC) ? PUBREL : PUBCOMP, 0, mypacketid)) <= 0) 00648 rc = FAILURE; 00649 else if ((rc = sendPacket(len, timer)) != SUCCESS) // send the PUBREL packet 00650 rc = FAILURE; // there was a problem 00651 if (rc == FAILURE) 00652 goto exit; // there was a problem 00653 if (packet_type == PUBREL) 00654 freeQoS2msgid(mypacketid); 00655 break; 00656 00657 case PUBCOMP: 00658 break; 00659 #endif 00660 case PINGRESP: 00661 ping_outstanding = false; 00662 break; 00663 } 00664 00665 if (keepalive() != SUCCESS) 00666 //check only keepalive FAILURE status so that previous FAILURE status can be considered as FAULT 00667 rc = FAILURE; 00668 00669 exit: 00670 if (rc == SUCCESS) 00671 rc = packet_type; 00672 else if (isconnected) 00673 closeSession(); 00674 return rc; 00675 } 00676 00677 00678 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00679 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::keepalive() 00680 { 00681 int rc = SUCCESS; 00682 static Timer ping_sent; 00683 00684 if (keepAliveInterval == 0) 00685 goto exit; 00686 00687 if (ping_outstanding) 00688 { 00689 if (ping_sent.expired()) 00690 { 00691 rc = FAILURE; // session failure 00692 #if defined(MQTT_DEBUG) 00693 DEBUG("PINGRESP not received in keepalive interval\r\n"); 00694 #endif 00695 } 00696 } 00697 else if (last_sent.expired() || last_received.expired()) 00698 { 00699 Timer timer(1000); 00700 int len = MQTTSerialize_pingreq(sendbuf, MAX_MQTT_PACKET_SIZE); 00701 if (len > 0 && (rc = sendPacket(len, timer)) == SUCCESS) // send the ping packet 00702 { 00703 ping_outstanding = true; 00704 ping_sent.countdown(this->keepAliveInterval); 00705 } 00706 } 00707 exit: 00708 return rc; 00709 } 00710 00711 00712 // only used in single-threaded mode where one command at a time is in process 00713 template<class Network, class Timer, int a, int b> 00714 int MQTT::Client<Network, Timer, a, b>::waitfor(int packet_type, Timer& timer) 00715 { 00716 int rc = FAILURE; 00717 00718 do 00719 { 00720 if (timer.expired()) 00721 break; // we timed out 00722 rc = cycle(timer); 00723 } 00724 while (rc != packet_type && rc >= 0); 00725 00726 return rc; 00727 } 00728 00729 00730 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00731 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::connect(MQTTPacket_connectData& options, connackData& data) 00732 { 00733 Timer connect_timer(command_timeout_ms); 00734 int rc = FAILURE; 00735 int len = 0; 00736 00737 if (isconnected) // don't send connect packet again if we are already connected 00738 goto exit; 00739 00740 this->keepAliveInterval = options.keepAliveInterval; 00741 this->cleansession = options.cleansession; 00742 if ((len = MQTTSerialize_connect(sendbuf, MAX_MQTT_PACKET_SIZE, &options)) <= 0) 00743 goto exit; 00744 if ((rc = sendPacket(len, connect_timer)) != SUCCESS) // send the connect packet 00745 goto exit; // there was a problem 00746 00747 if (this->keepAliveInterval > 0) 00748 last_received.countdown(this->keepAliveInterval); 00749 // this will be a blocking call, wait for the connack 00750 if (waitfor(CONNACK, connect_timer) == CONNACK) 00751 { 00752 data.rc = 0; 00753 data.sessionPresent = false; 00754 if (MQTTDeserialize_connack((unsigned char*)&data.sessionPresent, 00755 (unsigned char*)&data.rc, readbuf, MAX_MQTT_PACKET_SIZE) == 1) 00756 rc = data.rc; 00757 else 00758 rc = FAILURE; 00759 } 00760 else 00761 rc = FAILURE; 00762 00763 #if MQTTCLIENT_QOS2 00764 // resend any inflight publish 00765 if (inflightMsgid > 0 && inflightQoS == QOS2 && pubrel) 00766 { 00767 if ((len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBREL, 0, inflightMsgid)) <= 0) 00768 rc = FAILURE; 00769 else 00770 rc = publish(len, connect_timer, inflightQoS); 00771 } 00772 else 00773 #endif 00774 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 00775 if (inflightMsgid > 0) 00776 { 00777 memcpy(sendbuf, pubbuf, MAX_MQTT_PACKET_SIZE); 00778 rc = publish(inflightLen, connect_timer, inflightQoS); 00779 } 00780 #endif 00781 00782 exit: 00783 if (rc == SUCCESS) 00784 { 00785 isconnected = true; 00786 ping_outstanding = false; 00787 } 00788 return rc; 00789 } 00790 00791 00792 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00793 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::connect(MQTTPacket_connectData& options) 00794 { 00795 connackData data; 00796 return connect(options, data); 00797 } 00798 00799 00800 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00801 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::connect() 00802 { 00803 MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer; 00804 return connect(default_options); 00805 } 00806 00807 00808 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS> 00809 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::setMessageHandler(const char* topicFilter, messageHandler messageHandler) 00810 { 00811 int rc = FAILURE; 00812 int i = -1; 00813 00814 // first check for an existing matching slot 00815 for (i = 0; i < MAX_MESSAGE_HANDLERS; ++i) 00816 { 00817 if (messageHandlers[i].topicFilter != 0 && strcmp(messageHandlers[i].topicFilter, topicFilter) == 0) 00818 { 00819 if (messageHandler == 0) // remove existing 00820 { 00821 messageHandlers[i].topicFilter = 0; 00822 messageHandlers[i].fp.detach(); 00823 } 00824 rc = SUCCESS; // return i when adding new subscription 00825 break; 00826 } 00827 } 00828 // if no existing, look for empty slot (unless we are removing) 00829 if (messageHandler != 0) { 00830 if (rc == FAILURE) 00831 { 00832 for (i = 0; i < MAX_MESSAGE_HANDLERS; ++i) 00833 { 00834 if (messageHandlers[i].topicFilter == 0) 00835 { 00836 rc = SUCCESS; 00837 break; 00838 } 00839 } 00840 } 00841 if (i < MAX_MESSAGE_HANDLERS) 00842 { 00843 messageHandlers[i].topicFilter = topicFilter; 00844 messageHandlers[i].fp.attach(messageHandler); 00845 } 00846 } 00847 return rc; 00848 } 00849 00850 00851 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS> 00852 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::subscribe(const char* topicFilter, 00853 enum QoS qos, messageHandler messageHandler, subackData& data) 00854 { 00855 int rc = FAILURE; 00856 Timer timer(command_timeout_ms); 00857 int len = 0; 00858 MQTTString topic = {(char*)topicFilter, {0, 0}}; 00859 00860 if (!isconnected) 00861 goto exit; 00862 00863 len = MQTTSerialize_subscribe(sendbuf, MAX_MQTT_PACKET_SIZE, 0, packetid.getNext(), 1, &topic, (int*)&qos); 00864 if (len <= 0) 00865 goto exit; 00866 if ((rc = sendPacket(len, timer)) != SUCCESS) // send the subscribe packet 00867 goto exit; // there was a problem 00868 00869 if (waitfor(SUBACK, timer) == SUBACK) // wait for suback 00870 { 00871 int count = 0; 00872 unsigned short mypacketid; 00873 data.grantedQoS = 0; 00874 if (MQTTDeserialize_suback(&mypacketid, 1, &count, &data.grantedQoS, readbuf, MAX_MQTT_PACKET_SIZE) == 1) 00875 { 00876 if (data.grantedQoS != 0x80) 00877 rc = setMessageHandler(topicFilter, messageHandler); 00878 } 00879 } 00880 else 00881 rc = FAILURE; 00882 00883 exit: 00884 if (rc == FAILURE) 00885 closeSession(); 00886 return rc; 00887 } 00888 00889 00890 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS> 00891 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::subscribe(const char* topicFilter, enum QoS qos, messageHandler messageHandler) 00892 { 00893 subackData data; 00894 return subscribe(topicFilter, qos, messageHandler, data); 00895 } 00896 00897 00898 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS> 00899 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::unsubscribe(const char* topicFilter) 00900 { 00901 int rc = FAILURE; 00902 Timer timer(command_timeout_ms); 00903 MQTTString topic = {(char*)topicFilter, {0, 0}}; 00904 int len = 0; 00905 00906 if (!isconnected) 00907 goto exit; 00908 00909 if ((len = MQTTSerialize_unsubscribe(sendbuf, MAX_MQTT_PACKET_SIZE, 0, packetid.getNext(), 1, &topic)) <= 0) 00910 goto exit; 00911 if ((rc = sendPacket(len, timer)) != SUCCESS) // send the unsubscribe packet 00912 goto exit; // there was a problem 00913 00914 if (waitfor(UNSUBACK, timer) == UNSUBACK) 00915 { 00916 unsigned short mypacketid; // should be the same as the packetid above 00917 if (MQTTDeserialize_unsuback(&mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) == 1) 00918 { 00919 // remove the subscription message handler associated with this topic, if there is one 00920 setMessageHandler(topicFilter, 0); 00921 } 00922 } 00923 else 00924 rc = FAILURE; 00925 00926 exit: 00927 if (rc != SUCCESS) 00928 closeSession(); 00929 return rc; 00930 } 00931 00932 00933 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00934 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(int len, Timer& timer, enum QoS qos) 00935 { 00936 int rc; 00937 00938 if ((rc = sendPacket(len, timer)) != SUCCESS) // send the publish packet 00939 goto exit; // there was a problem 00940 00941 #if MQTTCLIENT_QOS1 00942 if (qos == QOS1) 00943 { 00944 if (waitfor(PUBACK, timer) == PUBACK) 00945 { 00946 unsigned short mypacketid; 00947 unsigned char dup, type; 00948 if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1) 00949 rc = FAILURE; 00950 else if (inflightMsgid == mypacketid) 00951 inflightMsgid = 0; 00952 } 00953 else 00954 rc = FAILURE; 00955 } 00956 #endif 00957 #if MQTTCLIENT_QOS2 00958 else if (qos == QOS2) 00959 { 00960 if (waitfor(PUBCOMP, timer) == PUBCOMP) 00961 { 00962 unsigned short mypacketid; 00963 unsigned char dup, type; 00964 if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1) 00965 rc = FAILURE; 00966 else if (inflightMsgid == mypacketid) 00967 inflightMsgid = 0; 00968 } 00969 else 00970 rc = FAILURE; 00971 } 00972 #endif 00973 00974 exit: 00975 if (rc != SUCCESS) 00976 closeSession(); 00977 return rc; 00978 } 00979 00980 00981 00982 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 00983 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, void* payload, size_t payloadlen, unsigned short& id, enum QoS qos, bool retained) 00984 { 00985 int rc = FAILURE; 00986 Timer timer(command_timeout_ms); 00987 MQTTString topicString = MQTTString_initializer; 00988 int len = 0; 00989 00990 if (!isconnected) 00991 goto exit; 00992 00993 topicString.cstring = (char*)topicName; 00994 00995 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 00996 if (qos == QOS1 || qos == QOS2) 00997 id = packetid.getNext(); 00998 #endif 00999 01000 len = MQTTSerialize_publish(sendbuf, MAX_MQTT_PACKET_SIZE, 0, qos, retained, id, 01001 topicString, (unsigned char*)payload, payloadlen); 01002 if (len <= 0) 01003 goto exit; 01004 01005 #if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2 01006 if (!cleansession) 01007 { 01008 memcpy(pubbuf, sendbuf, len); 01009 inflightMsgid = id; 01010 inflightLen = len; 01011 inflightQoS = qos; 01012 #if MQTTCLIENT_QOS2 01013 pubrel = false; 01014 #endif 01015 } 01016 #endif 01017 01018 rc = publish(len, timer, qos); 01019 exit: 01020 return rc; 01021 } 01022 01023 01024 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 01025 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, void* payload, size_t payloadlen, enum QoS qos, bool retained) 01026 { 01027 unsigned short id = 0; // dummy - not used for anything 01028 return publish(topicName, payload, payloadlen, id, qos, retained); 01029 } 01030 01031 01032 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 01033 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, Message& message) 01034 { 01035 return publish(topicName, message.payload, message.payloadlen, message.qos, message.retained); 01036 } 01037 01038 01039 template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b> 01040 int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::disconnect() 01041 { 01042 int rc = FAILURE; 01043 Timer timer(command_timeout_ms); // we might wait for incomplete incoming publishes to complete 01044 int len = MQTTSerialize_disconnect(sendbuf, MAX_MQTT_PACKET_SIZE); 01045 if (len > 0) 01046 rc = sendPacket(len, timer); // send the disconnect packet 01047 closeSession(); 01048 return rc; 01049 } 01050 01051 #endif
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