Files
TinyMqtt/src/TinyMqtt.cpp
2021-03-22 02:33:54 +01:00

540 lines
11 KiB
C++

#include "TinyMqtt.h"
#include <sstream>
#include <Streaming.h>
#if TINY_MQTT_DEBUG
#define debug(what) { Serial << __LINE__ << ' ' << what << endl; delay(100); }
#else
#define debug(what) {}
#endif
void outstring(const char* prefix, const char*p, uint16_t len)
{
return;
Serial << prefix << "='";
while(len--) Serial << (char)*p++;
Serial << '\'' << endl;
}
MqttBroker::MqttBroker(uint16_t port) : server(port)
{
}
MqttBroker::~MqttBroker()
{
while(clients.size())
{
delete clients[0];
}
}
// private constructor used by broker only
MqttClient::MqttClient(MqttBroker* parent, WiFiClient& new_client)
: parent(parent)
{
client = new WiFiClient(new_client);
alive = millis()+5000; // client expires after 5s if no CONNECT msg
}
MqttClient::MqttClient(MqttBroker* parent)
: parent(parent)
{
client = nullptr;
if (parent) parent->addClient(this);
}
MqttClient::~MqttClient()
{
close();
delete client;
}
void MqttClient::close()
{
debug("close " << id().c_str());
mqtt_connected = false;
if (client)
{
client->stop();
}
if (parent)
{
parent->removeClient(this);
parent=nullptr;
}
}
void MqttClient::connect(std::string broker, uint16_t port)
{
debug("cnx: closing");
close();
if (client) delete client;
client = new WiFiClient;
debug("Trying to connect to " << broker.c_str() << ':' << port);
if (client->connect(broker.c_str(), port))
{
debug("cnx: connecting");
message.create(MqttMessage::Type::Connect);
message.add("MQTT",4);
message.add(0x4); // Mqtt protocol version 3.1.1
message.add(0x0); // Connect flags TODO user / name
keep_alive = 1; // TODO not configurable
message.add(0x00); // keep_alive
message.add((char)keep_alive);
message.add(clientId);
debug("cnx: mqtt connecting");
message.sendTo(this);
debug("cnx: mqtt sent " << (int32_t)parent);
clientAlive(0);
}
}
void MqttBroker::addClient(MqttClient* client)
{
clients.push_back(client);
}
void MqttBroker::removeClient(MqttClient* remove)
{
for(auto it=clients.begin(); it!=clients.end(); it++)
{
auto client=*it;
if (client==remove)
{
debug("Remove " << clients.size());
clients.erase(it);
debug("Client removed " << clients.size());
return;
}
}
debug("Error cannot remove client"); // TODO should not occur
}
void MqttBroker::loop()
{
WiFiClient client = server.available();
if (client)
{
addClient(new MqttClient(this, client));
debug("New client (" << clients.size() << ')');
}
// for(auto it=clients.begin(); it!=clients.end(); it++)
// use index because size can change during the loop
for(int i=0; i<clients.size(); i++)
{
auto client = clients[i];
if (client->connected())
{
client->loop();
}
else
{
debug("Client " << client->id().c_str() << " Disconnected, parent=" << (int32_t)client->parent);
// Note: deleting a client not added by the broker itself will probably crash later.
delete client;
break;
}
}
}
MqttError MqttBroker::publish(const MqttClient* source, const Topic& topic, MqttMessage& msg)
{
MqttError retval = MqttOk;
debug("publish ");
int i=0;
for(auto client: clients)
{
i++;
Serial << "brk_" << (broker && broker->connected() ? "con" : "dis") <<
" srce=" << (source->isLocal() ? "loc" : "rem") << " clt#" << i << ", local=" << client->isLocal() << ", con=" << client->connected();
bool doit = false;
if (broker && broker->connected()) // Connected: R2 R3 R5 R6
{
// ext broker -> clients or
// or clients -> ext broker
if (source == broker) // broker -> clients
doit = true;
else // clients -> broker
retval=broker->publish(topic, msg);
}
else // Disconnected: R7
{
// All is allowed
doit = true;
}
Serial << ", doit=" << doit << ' ';
if (doit) client->publish(topic, msg);
debug("");
}
return retval;
}
bool MqttBroker::compareString(
const char* good,
const char* str,
uint8_t len) const
{
while(len-- and *good++==*str++);
return *good==0;
}
void MqttMessage::getString(const char* &buff, uint16_t& len)
{
len = (buff[0]<<8)|(buff[1]);
buff+=2;
}
void MqttClient::clientAlive(uint32_t more_seconds)
{
if (keep_alive)
{
alive=millis()+1000*(keep_alive+more_seconds);
}
else
alive=0;
}
void MqttClient::loop()
{
if (alive && (millis() > alive))
{
if (parent)
{
debug("timeout client");
close();
debug("closed");
}
else if (client && client->connected())
{
uint16_t pingreq = MqttMessage::Type::PingReq;
client->write((uint8_t*)(&pingreq), 2);
clientAlive(0);
// TODO when many MqttClient passes through a local browser
// there is no need to send one PingReq per instance.
}
}
while(client && client->available()>0)
{
message.incoming(client->read());
if (message.type())
{
processMessage();
}
}
}
void MqttClient::processMessage()
{
std::string error;
std::string s;
// Serial << "---> INCOMING " << _HEX(message.type()) << ", mem=" << ESP.getFreeHeap() << endl;
auto header = message.getVHeader();
const char* payload;
uint16_t len;
bool bclose=true;
switch(message.type() & 0XF0)
{
case MqttMessage::Type::Connect:
if (mqtt_connected)
{
debug("already connected");
break;
}
payload = header+10;
mqtt_flags = header[7];
keep_alive = (header[8]<<8)|(header[9]);
if (strncmp("MQTT", header+2,4))
{
debug("bad mqtt header");
break;
}
if (header[6]!=0x04)
{
debug("unknown level");
break; // Level 3.1.1
}
// ClientId
message.getString(payload, len);
debug("client id len=" << len);
if (len>30)
{
Serial << '(';
for(int i=0; i<30; i++)
{
if (i%5==0) Serial << ' ';
char c=*(header+i);
Serial << (c < 32 ? '.' : c);
}
Serial << " )" << endl;
debug("Bad client id length");
break;
}
clientId = std::string(payload, len);
payload += len;
if (mqtt_flags & FlagWill) // Will topic
{
message.getString(payload, len); // Will Topic
outstring("WillTopic", payload, len);
payload += len;
message.getString(payload, len); // Will Message
outstring("WillMessage", payload, len);
payload += len;
}
// FIXME forgetting credential is allowed (security hole)
if (mqtt_flags & FlagUserName)
{
message.getString(payload, len);
if (!parent->checkUser(payload, len)) break;
payload += len;
}
if (mqtt_flags & FlagPassword)
{
message.getString(payload, len);
if (!parent->checkPassword(payload, len)) break;
payload += len;
}
Serial << "Connected client:" << clientId.c_str() << ", keep alive=" << keep_alive << '.' << endl;
bclose = false;
mqtt_connected=true;
// Reuse received msg
message.create(MqttMessage::Type::Connack);
message.add(0); // Session present (not implemented)
message.add(0); // Connection accepted
message.sendTo(this);
break;
case MqttMessage::Type::PingReq:
if (!mqtt_connected) break;
if (client)
{
uint16_t pingreq = MqttMessage::Type::PingResp;
client->write((uint8_t*)(&pingreq), 2);
bclose = false;
}
else
{
debug("internal pingreq ?");
}
break;
case MqttMessage::Type::Subscribe:
if (!mqtt_connected) break;
payload = header+2;
message.getString(payload, len); // Topic
outstring("Subscribes", payload, len);
subscribe(Topic(payload, len));
bclose = false;
// TODO SUBACK
break;
case MqttMessage::Type::Publish:
if (!mqtt_connected) break;
{
uint8_t qos = message.type() & 0x6;
payload = header;
message.getString(payload, len);
Topic published(payload, len);
payload += len;
len=message.end()-payload;
// Serial << "Received Publish (" << published.str().c_str() << ") size=" << (int)len
// << '(' << std::string(payload, len).c_str() << ')' << " msglen=" << message.length() << endl;
if (qos) payload+=2; // ignore packet identifier if any
// TODO reset DUP
// TODO reset RETAIN
debug("publishing to parent");
parent->publish(this, published, message);
// TODO should send PUBACK
bclose = false;
}
break;
case MqttMessage::Type::PubAck:
if (!mqtt_connected) break;
bclose = false;
break;
default:
bclose=true;
break;
};
if (bclose)
{
Serial << "*************** Error msg 0x" << _HEX(message.type());
if (error.length()) Serial << ':' << error.c_str();
Serial << endl;
close();
}
else
{
clientAlive(5);
}
message.reset();
}
bool Topic::matches(const Topic& topic) const
{
if (getIndex() == topic.getIndex()) return true;
if (str() == topic.str()) return true;
return false;
}
// publish from local client
MqttError MqttClient::publish(const Topic& topic, const char* payload, size_t pay_length)
{
MqttMessage msg;
msg.create(MqttMessage::Publish);
msg.add(topic);
msg.add(payload, pay_length, false);
if (parent)
return parent->publish(this, topic, msg);
else if (client)
msg.sendTo(this);
else
return MqttNowhereToSend;
}
// republish a received publish if it matches any in subscriptions
MqttError MqttClient::publish(const Topic& topic, MqttMessage& msg)
{
MqttError retval=MqttOk;
debug("mqttclient publish " << subscriptions.size());
for(const auto& subscription: subscriptions)
{
Serial << " client=" << (int32_t)client << ", topic " << topic.str().c_str() << ' ';
if (subscription.matches(topic))
{
Serial << " match/send";
if (client)
{
msg.sendTo(this);
}
else if (callback)
{
callback(this, topic, nullptr, 0); // TODO Payload
}
}
Serial << endl;
}
return retval;
}
void MqttMessage::reset()
{
buffer.clear();
state=FixedHeader;
size=0;
}
void MqttMessage::incoming(char in_byte)
{
buffer += in_byte;
switch(state)
{
case FixedHeader:
size=0;
state = Length;
break;
case Length:
size = (size<<7) + (in_byte & 0x3F);
if (size > MaxBufferLength)
{
state = Error;
}
else if ((in_byte & 0x80) == 0)
{
vheader = buffer.length();
if (size==0)
state = Complete;
else
state = VariableHeader;
}
break;
case VariableHeader:
case PayLoad:
--size;
if (size==0)
{
state=Complete;
// hexdump("rec");
}
break;
case Create:
size++;
break;
case Complete:
default:
Serial << "Spurious " << _HEX(in_byte) << endl;
reset();
break;
}
if (buffer.length() > MaxBufferLength) // TODO magic 256 ?
{
debug("Too long " << state);
reset();
}
}
void MqttMessage::add(const char* p, size_t len, bool addLength)
{
if (addLength)
{
incoming(len>>8);
incoming(len & 0xFF);
}
while(len--) incoming(*p++);
}
void MqttMessage::encodeLength(char* msb, int length)
{
do
{
uint8_t encoded(length & 0x7F);
length >>=7;
if (length) encoded |= 0x80;
*msb++ = encoded;
} while (length);
};
void MqttMessage::sendTo(MqttClient* client)
{
if (buffer.size()>2)
{
encodeLength(&buffer[1], buffer.size()-2);
// hexdump("snd");
client->write(&buffer[0], buffer.size());
}
else
{
Serial << "??? Invalid send" << endl;
}
}
void MqttMessage::hexdump(const char* prefix) const
{
if (prefix) Serial << prefix << ' ';
Serial << "size(" << buffer.size() << ") : ";
for(const char chr: buffer)
{
if (chr<16) Serial << '0';
Serial << _HEX(chr) << ' ';
}
Serial << endl;
}