RadioLibSmol/src/protocols/MQTT/MQTT.cpp
2020-07-10 08:51:43 +02:00

472 lines
12 KiB
C++

#include "MQTT.h"
#if !defined(RADIOLIB_EXCLUDE_MQTT)
MQTTClient::MQTTClient(TransportLayer* tl, uint16_t port) {
_tl = tl;
_port = port;
_packetId = 1;
}
int16_t MQTTClient::connect(const char* host, const char* clientId, const char* userName, const char* password, uint16_t keepAlive, bool cleanSession, const char* willTopic, const char* willMessage) {
// encode packet length
size_t clientIdLen = strlen(clientId);
size_t userNameLen = strlen(userName);
size_t passwordLen = strlen(password);
size_t willTopicLen = strlen(willTopic);
size_t willMessageLen = strlen(willMessage);
uint32_t remainingLength = 10 + (2 + clientIdLen);
if(userNameLen > 0) {
remainingLength += (2 + userNameLen);
}
if(passwordLen > 0) {
remainingLength += (2 + passwordLen);
}
if((willTopicLen > 0) && (willMessageLen > 0)) {
remainingLength += (2 + willTopicLen) + (2 + willMessageLen);
}
uint8_t encoded[] = {0, 0, 0, 0};
size_t encodedBytes = encodeLength(remainingLength, encoded);
// build the CONNECT packet
#ifdef RADIOLIB_STATIC_ONLY
uint8_t packet[256];
#else
uint8_t* packet = new uint8_t[1 + encodedBytes + remainingLength];
#endif
// fixed header
packet[0] = (MQTT_CONNECT << 4) | 0b0000;
memcpy(packet + 1, encoded, encodedBytes);
// variable header
// protocol name
size_t pos = encodedBytes + 1;
packet[pos++] = 0x00;
packet[pos++] = 0x04;
memcpy(packet + pos, "MQTT", 4);
pos += 4;
// protocol level
packet[pos++] = 0x04;
// flags
packet[pos++] = 0x00;
if(cleanSession) {
packet[encodedBytes + 8] |= MQTT_CONNECT_CLEAN_SESSION;
}
// keep alive interval in seconds
packet[pos++] = (keepAlive & 0xFF00) >> 8;
packet[pos++] = keepAlive & 0x00FF;
// payload
// clientId
packet[pos++] = (clientIdLen & 0xFF00) >> 8;
packet[pos++] = clientIdLen & 0x00FF;
memcpy(packet + pos, clientId, clientIdLen);
pos += clientIdLen;
// will topic and message
if((willTopicLen > 0) && (willMessageLen > 0)) {
packet[encodedBytes + 8] |= MQTT_CONNECT_WILL_FLAG;
packet[pos++] = (willTopicLen & 0xFF00) >> 8;
packet[pos++] = willTopicLen & 0x00FF;
memcpy(packet + pos, willTopic, willTopicLen);
pos += willTopicLen;
packet[pos++] = (willMessageLen & 0xFF00) >> 8;
packet[pos++] = willMessageLen & 0x00FF;
memcpy(packet + pos, willMessage, willMessageLen);
pos += willMessageLen;
}
// user name
if(userNameLen > 0) {
packet[encodedBytes + 8] |= MQTT_CONNECT_USER_NAME_FLAG;
packet[pos++] = (userNameLen & 0xFF00) >> 8;
packet[pos++] = userNameLen & 0x00FF;
memcpy(packet + pos, userName, userNameLen);
pos += userNameLen;
}
// password
if(passwordLen > 0) {
packet[encodedBytes + 8] |= MQTT_CONNECT_PASSWORD_FLAG;
packet[pos++] = (passwordLen & 0xFF00) >> 8;;
packet[pos++] = passwordLen & 0x00FF;
memcpy(packet + pos, password, passwordLen);
}
// create TCP connection
int16_t state = _tl->openTransportConnection(host, "TCP", _port, keepAlive);
if(state != ERR_NONE) {
#ifndef RADIOLIB_STATIC_ONLY
delete[] packet;
#endif
return(state);
}
// send MQTT packet
state = _tl->send(packet, 1 + encodedBytes + remainingLength);
#ifndef RADIOLIB_STATIC_ONLY
delete[] packet;
#endif
if(state != ERR_NONE) {
return(state);
}
// get the response length (MQTT CONNACK response has to be 4 bytes long)
size_t numBytes = _tl->getNumBytes();
if(numBytes != 4) {
return(ERR_RESPONSE_MALFORMED_AT);
}
// read the response
#ifdef RADIOLIB_STATIC_ONLY
uint8_t response[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* response = new uint8_t[numBytes];
#endif
_tl->receive(response, numBytes);
if((response[0] == MQTT_CONNACK << 4) && (response[1] == 2)) {
uint8_t returnCode = response[3];
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(returnCode);
}
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(ERR_RESPONSE_MALFORMED);
}
int16_t MQTTClient::disconnect() {
// build the DISCONNECT packet
uint8_t packet[2];
// fixed header
packet[0] = (MQTT_DISCONNECT << 4) | 0b0000;
packet[1] = 0x00;
// send MQTT packet
int16_t state = _tl->send(packet, 2);
if(state != ERR_NONE) {
return(state);
}
// close tl connection
return(_tl->closeTransportConnection());
}
int16_t MQTTClient::publish(String& topic, String& message) {
return(MQTTClient::publish(topic.c_str(), message.c_str()));
}
int16_t MQTTClient::publish(const char* topic, const char* message) {
// encode packet length
size_t topicLen = strlen(topic);
size_t messageLen = strlen(message);
uint32_t remainingLength = (2 + topicLen) + messageLen;
uint8_t encoded[] = {0, 0, 0, 0};
size_t encodedBytes = encodeLength(remainingLength, encoded);
// build the PUBLISH packet
#ifdef RADIOLIB_STATIC_ONLY
uint8_t packet[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* packet = new uint8_t[1 + encodedBytes + remainingLength];
#endif
// fixed header
packet[0] = (MQTT_PUBLISH << 4) | 0b0000;
memcpy(packet + 1, encoded, encodedBytes);
// variable header
// topic name
size_t pos = encodedBytes + 1;
packet[pos++] = (topicLen & 0xFF00) >> 8;
packet[pos++] = topicLen & 0x00FF;
memcpy(packet + pos, topic, topicLen);
pos += topicLen;
// packet ID
// payload
// message
memcpy(packet + pos, message, messageLen);
// send MQTT packet
int16_t state = _tl->send(packet, 1 + encodedBytes + remainingLength);
#ifndef RADIOLIB_STATIC_ONLY
delete[] packet;
#endif
return(state);
/// \todo implement QoS > 0 and PUBACK response checking
}
int16_t MQTTClient::subscribe(const char* topicFilter) {
// encode packet length
size_t topicFilterLen = strlen(topicFilter);
uint32_t remainingLength = 2 + (2 + topicFilterLen + 1);
uint8_t encoded[] = {0, 0, 0, 0};
size_t encodedBytes = encodeLength(remainingLength, encoded);
// build the SUBSCRIBE packet
#ifdef RADIOLIB_STATIC_ONLY
uint8_t packet[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* packet = new uint8_t[1 + encodedBytes + remainingLength];
#endif
// fixed header
packet[0] = (MQTT_SUBSCRIBE << 4) | 0b0010;
memcpy(packet + 1, encoded, encodedBytes);
// variable header
// packet ID
size_t pos = encodedBytes + 1;
uint16_t packetId = _packetId++;
packet[pos++] = (packetId & 0xFF00) >> 8;
packet[pos++] = packetId & 0x00FF;
// payload
// topic filter
packet[pos++] = (topicFilterLen & 0xFF00) >> 8;;
packet[pos++] = topicFilterLen & 0x00FF;
memcpy(packet + pos, topicFilter, topicFilterLen);
pos += topicFilterLen;
packet[pos++] = 0x00; // QoS 0
// send MQTT packet
int16_t state = _tl->send(packet, 1 + encodedBytes + remainingLength);
#ifndef RADIOLIB_STATIC_ONLY
delete[] packet;
#endif
if(state != ERR_NONE) {
return(state);
}
// get the response length (MQTT SUBACK response has to be 5 bytes long for single subscription)
size_t numBytes = _tl->getNumBytes();
if(numBytes != 5) {
return(ERR_RESPONSE_MALFORMED_AT);
}
// read the response
#ifdef RADIOLIB_STATIC_ONLY
uint8_t response[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* response = new uint8_t[numBytes];
#endif
_tl->receive(response, numBytes);
if((response[0] == MQTT_SUBACK << 4) && (response[1] == 3)) {
// check packet ID
uint16_t receivedId = response[3] | response[2] << 8;
int16_t returnCode = response[4];
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
if(receivedId != packetId) {
return(ERR_MQTT_UNEXPECTED_PACKET_ID);
}
return(returnCode);
}
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(ERR_RESPONSE_MALFORMED);
}
int16_t MQTTClient::unsubscribe(const char* topicFilter) {
// encode packet length
size_t topicFilterLen = strlen(topicFilter);
uint32_t remainingLength = 2 + (2 + topicFilterLen);
uint8_t encoded[] = {0, 0, 0, 0};
size_t encodedBytes = encodeLength(remainingLength, encoded);
// build the UNSUBSCRIBE packet
#ifdef RADIOLIB_STATIC_ONLY
uint8_t packet[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* packet = new uint8_t[1 + encodedBytes + remainingLength];
#endif
// fixed header
packet[0] = (MQTT_UNSUBSCRIBE << 4) | 0b0010;
memcpy(packet + 1, encoded, encodedBytes);
// variable header
// packet ID
size_t pos = encodedBytes + 1;
uint16_t packetId = _packetId++;
packet[pos++] = (packetId & 0xFF00) >> 8;
packet[pos++] = packetId & 0x00FF;
// payload
// topic filter
packet[pos++] = (topicFilterLen & 0xFF00) >> 8;;
packet[pos++] = topicFilterLen & 0x00FF;
memcpy(packet + pos, topicFilter, topicFilterLen);
// send MQTT packet
int16_t state = _tl->send(packet, 1 + encodedBytes + remainingLength);
#ifndef RADIOLIB_STATIC_ONLY
delete[] packet;
#endif
if(state != ERR_NONE) {
return(state);
}
// get the response length (MQTT UNSUBACK response has to be 4 bytes long)
size_t numBytes = _tl->getNumBytes();
if(numBytes != 4) {
return(ERR_RESPONSE_MALFORMED_AT);
}
// read the response
#ifdef RADIOLIB_STATIC_ONLY
uint8_t response[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* response = new uint8_t[numBytes];
#endif
_tl->receive(response, numBytes);
if((response[0] == MQTT_UNSUBACK << 4) && (response[1] == 2)) {
// check packet ID
uint16_t receivedId = response[3] | response[2] << 8;
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
if(receivedId != packetId) {
return(ERR_MQTT_UNEXPECTED_PACKET_ID);
}
return(ERR_NONE);
}
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(ERR_RESPONSE_MALFORMED);
}
int16_t MQTTClient::ping() {
// build the PINGREQ packet
uint8_t packet[2];
// fixed header
packet[0] = (MQTT_PINGREQ << 4) | 0b0000;
packet[1] = 0x00;
// send MQTT packet
int16_t state = _tl->send(packet, 2);
if(state != ERR_NONE) {
return(state);
}
// get the response length (MQTT PINGRESP response has to be 2 bytes long)
size_t numBytes = _tl->getNumBytes();
if(numBytes != 2) {
return(ERR_RESPONSE_MALFORMED_AT);
}
// read the response
#ifdef RADIOLIB_STATIC_ONLY
uint8_t response[RADIOLIB_STATIC_ARRAY_SIZE];
#else
uint8_t* response = new uint8_t[numBytes];
#endif
_tl->receive(response, numBytes);
if((response[0] == MQTT_PINGRESP << 4) && (response[1] == 0)) {
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(ERR_NONE);
}
#ifndef RADIOLIB_STATIC_ONLY
delete[] response;
#endif
return(ERR_RESPONSE_MALFORMED);
}
int16_t MQTTClient::check(void (*func)(const char*, const char*)) {
// ping the server
int16_t state = ping();
if(state != ERR_NONE) {
return(state);
}
// check new data
size_t numBytes = _tl->getNumBytes();
if(numBytes == 0) {
return(ERR_MQTT_NO_NEW_PACKET_AVAILABLE);
}
// read the PUBLISH packet from server
uint8_t* dataIn = new uint8_t[numBytes];
_tl->receive(dataIn, numBytes);
if(dataIn[0] == MQTT_PUBLISH << 4) {
uint8_t remLenFieldLen = 0;
uint32_t remainingLength = decodeLength(dataIn + 1, remLenFieldLen);
// get the topic
size_t topicLength = dataIn[remLenFieldLen + 2] | dataIn[remLenFieldLen + 1] << 8;
char* topic = new char[topicLength + 1];
memcpy(topic, dataIn + 4, topicLength);
topic[topicLength] = 0x00;
// get the message
size_t messageLength = remainingLength - topicLength - 2;
char* message = new char[messageLength + 1];
memcpy(message, dataIn + remLenFieldLen + 3 + topicLength, messageLength);
message[messageLength] = 0x00;
// execute the callback function provided by user
func(topic, message);
delete[] topic;
delete[] message;
delete[] dataIn;
return(ERR_NONE);
}
delete[] dataIn;
return(ERR_MQTT_NO_NEW_PACKET_AVAILABLE);
}
size_t MQTTClient::encodeLength(uint32_t len, uint8_t* encoded) {
// algorithm to encode packet length as per MQTT specification 3.1.1
size_t i = 0;
do {
encoded[i] = len % 128;
len /= 128;
if(len > 0) {
encoded[i] |= 128;
}
i++;
} while(len > 0);
return(i);
}
uint32_t MQTTClient::decodeLength(uint8_t* encoded, uint8_t& numBytes) {
// algorithm to decode packet length as per MQTT specification 3.1.1
uint32_t mult = 1;
uint32_t len = 0;
uint8_t i = 0;
do {
len += (encoded[i] & 127) * mult;
mult *= 128;
if(mult > 2097152) {
// malformed remaining length
return(0);
}
} while((encoded[i++] & 128) != 0);
numBytes = i;
return len;
}
#endif