First cmmit

.gitignore

@@ -0,0 +1 @@
+*~

examples/simple-broker/simple-broker.ino

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+#include <ESP8266WiFi.h>
+#include "TinyMqtt.h"   // https://github.com/hsaturn/TinyMqtt
+#include <Streaming.h>  // https://github.com/janelia-arduino/Streaming
+
+const char *ssid = ;      // Put here your wifi SSID ("ssid")
+const char *password = ;  // Put here your Wifi password ("pwd")
+
+#define PORT 1883
+MqttBroker broker(PORT);
+
+void setup() 
+{
+  Serial.begin(115200);
+
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+ 
+  while (WiFi.status() != WL_CONNECTED) {   
+    delay(500);
+    Serial << '.';
+    delay(500);
+  }
+  Serial << "Connected to " << ssid << "IP address: " << WiFi.localIP() << endl;  
+
+  broker.begin();
+  Serial << "Broker ready : " << WiFi.localIP() << " on port " << PORT << endl;
+}
+
+void loop()
+{
+  broker.loop();
+}

keywords.txt

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+#######################################
+# Syntax Coloring Map For TinyMQTT
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+MqttBroker	KEYWORD1
+MqttClient  KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+
+#######################################
+# Constants (LITERAL1)
+#######################################

library.json

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+{
+    "name": "TinyMqtt",
+    "keywords": "ethernet, mqtt, m2m, iot",
+    "description": "MQTT is a lightweight messaging protocol ideal for small devices. This library allows you to send and receive MQTT messages. It does support MQTT 3.1.1 without any QOS.",
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/hsaturn/TinyMqtt.git"
+    },
+    "version": "0.1",
+    "exclude": "",
+    "examples": "examples/*/*.ino",
+    "frameworks": "arduino",
+    "platforms": [
+        "atmelavr",
+        "espressif8266",
+        "espressif32"
+    ]
+}

library.properties

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+name=TinyMqtt
+version=0.1
+author=HSaturn <hsaturn@gmail.com>
+maintainer=HSaturn <hsaturn@gmail.com>
+sentence=A tiny broker and client library for MQTT messaging.
+paragraph=MQTT is a lightweight messaging protocol ideal for small devices. This library allows you to send and receive MQTT messages. It does support MQTT 3.1.1 without any QOS.
+category=Communication
+url=https://github.com/hsaturn/TinyMqtt
+architectures=*

src/StringIndexer.cpp

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+#include "StringIndexer.h"
+
+std::map<StringIndexer::index_t, StringIndexer::StringCounter> StringIndexer::strings;

src/StringIndexer.h

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+#pragma once
+#include <map>
+#include <string>
+#include <string.h>
+#include <Streaming.h>
+#include <ESP8266WiFi.h>
+
+/***
+ * Allows to store up to 255 different strings with one byte class
+ * very memory efficient when one string is used many times.
+ */
+class StringIndexer
+{
+	class StringCounter
+	{
+		std::string str;
+		uint8_t used=0;
+		friend class StringIndexer;
+	};
+	public:
+		using index_t=uint8_t;
+
+		static const index_t strToIndex(const char* str, uint8_t len)
+		{
+			for(auto it=strings.begin(); it!=strings.end(); it++)
+			{
+				if (strncmp(it->second.str.c_str(), str, len)==0)
+				{
+					it->second.used++;
+					return it->first;
+				}
+			}
+			for(index_t index=0; index<255; index++)
+			{
+				if (strings.find(index)==strings.end())
+				{
+					strings[index].str = std::string(str, len);
+					strings[index].used++;
+					Serial << "Creating index " << index << " for (" << strings[index].str.c_str() << ") len=" << len << endl;
+					return index;
+				}
+			}
+			return 0;	// TODO out of indexes
+		}
+
+		static const std::string& str(const index_t& index)
+		{
+			static std::string dummy;
+			const auto& it=strings.find(index);
+			if (it == strings.end()) return dummy;
+			return it->second.str;
+		}
+
+		static void use(const index_t& index)
+		{
+			auto it=strings.find(index);
+			if (it != strings.end()) it->second.used++;
+		}
+
+		static void release(const index_t& index)
+		{
+			auto it=strings.find(index);
+			if (it != strings.end())
+			{
+				it->second.used--;
+				if (it->second.used == 0)
+				{
+					strings.erase(it);
+					Serial << "Removing string(" << it->second.str.c_str() << ") size=" << strings.size() << endl;
+				}
+			}
+		}
+
+	private:
+		static std::map<index_t, StringCounter> strings;
+};
+
+class IndexedString
+{
+	public:
+		IndexedString(const IndexedString& source)
+		{
+			StringIndexer::use(source.index);
+			index = source.index;
+		}
+
+		IndexedString(const char* str, uint8_t len)
+		{
+			index=StringIndexer::strToIndex(str, len);
+		}
+
+		~IndexedString() { StringIndexer::release(index); }
+
+		IndexedString& operator=(const IndexedString& source)
+		{
+			StringIndexer::use(source.index);
+			index = source.index;
+			return *this;
+		}
+
+		friend bool operator<(const IndexedString& i1, const IndexedString& i2)
+		{
+			return i1.index < i2.index;
+		}
+
+		const std::string& str() const { return StringIndexer::str(index); }
+
+		const StringIndexer::index_t getIndex() const { return index; }
+
+	private:
+		StringIndexer::index_t index;
+};

src/TinyMqtt.cpp

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+#include "TinyMqtt.h"
+#include <sstream>
+#include <Streaming.h>
+
+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)
+{
+}
+
+MqttCnx::MqttCnx(MqttBroker* parent, WiFiClient& new_client)
+	: parent(parent),
+	mqtt_connected(false)
+{
+	client = new_client ? new WiFiClient(new_client) : nullptr;
+	clientAlive();
+}
+
+MqttCnx::~MqttCnx()
+{
+	close();
+}
+
+void MqttCnx::close()
+{
+	if (client)
+	{
+		client->stop();
+		delete client;
+		client = nullptr;
+	}
+}
+
+void MqttBroker::loop()
+{
+  WiFiClient client = server.available();
+  
+  if (client)
+	{
+		clients.push_back(new MqttCnx(this, client));
+		Serial << "New client (" << clients.size() << ')' << endl;
+	}
+
+  for(auto it=clients.begin(); it!=clients.end(); it++)
+	{
+		auto client=*it;
+    if(client->connected())
+    {
+			client->loop();
+		}
+		else
+		{
+      Serial << "Client " << client->id().c_str() << "  Disconnected" << endl;
+			clients.erase(it);
+			delete client;
+			break;
+    }
+	}
+}
+
+void MqttBroker::publish(const Topic& topic, MqttMessage& msg)
+{
+	for(auto client: clients)
+		client->publish(topic, msg);
+}
+
+bool MqttBroker::compareString(
+		const char* good,
+		const char* str,
+		uint8_t len) const
+{
+	while(len-- and *good++==*str++);
+
+	return *good==0;
+}
+
+void MqttMessage::getString(char* &buffer, uint16_t& len)
+{
+	len = (buffer[0]<<8)|(buffer[1]);
+	buffer+=2;
+}
+
+void MqttCnx::clientAlive()
+{
+	if (keep_alive)
+	{
+		alive=millis()+1000*(keep_alive+5);
+	}
+	else
+		alive=0;
+}
+
+void MqttCnx::loop()
+{
+	if (alive && (millis() > alive))
+	{
+		Serial << "timeout client" << endl;
+		close();
+	}
+
+	while(client && client->available()>0)
+	{
+		message.incoming(client->read());
+		if (message.type())
+		{
+			processMessage();
+		}
+	}
+}
+
+void MqttCnx::processMessage()
+{
+	std::string error;
+	std::string s;
+	// Serial << "---> INCOMING " << _HEX(message.type()) << ", mem=" << ESP.getFreeHeap() << endl;
+  auto header = message.getVHeader();
+  char* payload;
+  uint16_t len;
+	bool bclose=true;
+
+	switch(message.type() & 0XF0)
+	{
+		case MqttMessage::Type::Connect:
+			if (mqtt_connected) break;
+			payload = header+10;
+			flags = header[7];
+			keep_alive = (header[8]<<8)|(header[9]);
+			if (strncmp("MQTT", header+2,4)) break;
+			if (header[6]!=0x04) break;	// Level 3.1.1
+
+			// ClientId
+			message.getString(payload, len);
+			clientId = std::string(payload, len);
+			payload += len;
+
+			if (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;
+			}
+			if (flags & FlagUserName)
+			{
+				message.getString(payload, len);
+				if (!parent->checkUser(payload, len)) break;
+				payload += len;
+			}
+			if (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:
+			message.create(MqttMessage::Type::PingResp);
+			message.add(0);
+			message.sendTo(this);
+			bclose = false;
+			break;
+
+		case MqttMessage::Type::Subscribe:
+			if (!mqtt_connected) break;
+			payload = header+2;
+			message.getString(payload, len);	// Topic
+			outstring("Subscribes", payload, len);
+
+			subscriptions.insert(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
+				parent->publish(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();
+	}
+	message.reset();
+}
+
+bool Topic::matches(const Topic& topic) const
+{
+	if (getIndex() == topic.getIndex()) return true;
+	if (str() == topic.str()) return true;
+	return false;
+}
+
+void MqttCnx::publish(const Topic& topic, MqttMessage& msg)
+{
+	for(const auto& subscription: subscriptions)
+	{
+		if (subscription.matches(topic))
+		{
+			// Serial << "Republishing " << topic.str().c_str() << " to " << clientId.c_str() << endl;
+			msg.sendTo(this);
+		}
+	}
+}
+
+void MqttMessage::reset()
+{
+	curr=buffer;
+	*curr=0;	// Type Unknown
+	state=FixedHeader;
+	size=0;
+}
+
+void MqttMessage::incoming(char in_byte)
+{
+	*curr++ = 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 = curr;
+				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:
+			curr--;
+			Serial << "Spurious " << _HEX(in_byte) << endl;
+			state = Error;
+			break;
+	}
+	if (curr-buffer > 250)
+	{
+		Serial << "Too much incoming bytes." << endl;
+		curr=buffer;
+	}
+}
+
+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(MqttCnx* client)
+{
+	if (curr-buffer-2 >= 0)
+	{
+		encodeLength(buffer+1, curr-buffer-2);
+		// hexdump("snd");
+		client->write(buffer, curr-buffer);
+	}
+	else
+	{
+		Serial << "??? Invalid send" << endl;
+		Serial << (long)end() << "-" << (long)buffer << endl;
+	}
+}
+
+void MqttMessage::hexdump(const char* prefix) const
+{
+	if (prefix) Serial << prefix << ' ';
+	Serial << (long)buffer << "-" << (long)curr << " : ";
+		const char* p=buffer;
+		while(p!=curr)
+		{
+			if (*p<16) Serial << '0';
+			Serial << _HEX(*p) << ' ';
+			p++;
+		}
+		Serial << endl;
+}

src/TinyMqtt.h

@@ -0,0 +1,160 @@
+#include <ESP8266WiFi.h>
+#include <vector>
+#include <set>
+#include <string>
+#include "StringIndexer.h"
+
+#define MaxBufferLength 255
+
+class Topic : public IndexedString
+{
+	public:
+		Topic(const char* s, uint8_t len) : IndexedString(s,len){}
+		Topic(const char* s) : Topic(s, strlen(s)) {}
+
+		bool matches(const Topic&) const;
+};
+
+class MqttCnx;
+class MqttMessage
+{
+	public:
+		enum Type
+		{
+			Unknown   =    0,
+			Connect   = 0x10,
+			Connack   = 0x20,
+			Publish   = 0x30,
+			PubAck    = 0x40,
+			Subscribe = 0x80,
+			PingReq   = 0xC0,
+			PingResp  = 0xD0,
+		};
+		enum State
+		{
+			FixedHeader=0,
+			Length=1,
+			VariableHeader=2,
+			PayLoad=3,
+			Complete=4,
+			Error=5,
+			Create=6
+		};
+
+		MqttMessage() { reset(); }
+		MqttMessage(Type t) { create(t); }
+		void incoming(char byte);
+		void add(char byte) { incoming(byte); }
+		char* getVHeader() const { return vheader; }
+		char* end() const { return curr; }
+		uint16_t length() const { return curr-buffer; }
+
+		void reset();
+
+		// buff is MSB/LSB/STRING
+		// output buff+=2, len=length(str)
+		void getString(char* &buff, uint16_t& len);
+
+
+		Type type() const
+		{
+			return state == Complete ? static_cast<Type>(buffer[0]) : Unknown;
+		}
+
+		void create(Type type)
+		{
+			buffer[0]=type;
+			curr=buffer+2;
+			vheader=curr;
+			size=0;
+			state=Create;
+		}
+		void sendTo(MqttCnx*);
+		void hexdump(const char* prefix=nullptr) const;
+
+	private:
+		void encodeLength(char* msb, int length);
+
+	  char buffer[256];	// TODO 256 ?
+		char* vheader;
+		char* curr;
+		uint16_t size;	// bytes left to receive
+		State state;
+};
+
+class MqttBroker;
+class MqttCnx
+{
+	enum Flags
+	{
+		FlagUserName = 128,
+		FlagPassword = 64,
+		FlagWillRetain = 32,	// unsupported
+		FlagWillQos = 16 | 8, // unsupported
+		FlagWill = 4,			// unsupported
+		FlagCleanSession = 2,	// unsupported
+		FlagReserved = 1
+	};
+	public:
+		MqttCnx(MqttBroker* parent, WiFiClient& client);
+
+		~MqttCnx();
+
+		bool connected() { return client && client->connected(); }
+		void write(const char* buf, size_t length)
+		{ if (client) client->write(buf, length); }
+
+		const std::string& id() const { return clientId; }
+
+		void loop();
+		void close();
+		void publish(const Topic& topic, MqttMessage& msg);
+
+	private:
+		void clientAlive();
+		void processMessage();
+
+		char flags;
+		uint32_t keep_alive;
+		uint32_t alive;
+		bool mqtt_connected;
+		WiFiClient* client;
+		MqttMessage message;
+		MqttBroker* parent;
+		std::set<Topic>	subscriptions;
+		std::string clientId;
+};
+
+class MqttClient
+{
+	public:
+		MqttClient(IPAddress broker) : broker_ip(broker) {}
+
+	protected:
+		IPAddress broker_ip;
+};
+
+class MqttBroker
+{
+	public:
+		MqttBroker(uint16_t port);
+
+		void begin() { server.begin(); }
+		void loop();
+
+		bool checkUser(const char* user, uint8_t len) const
+		{ return compareString(auth_user, user, len); }
+
+		bool checkPassword(const char* password, uint8_t len) const
+		{ return compareString(auth_password, password, len); }
+
+		void publish(const Topic& topic, MqttMessage& msg);
+
+	private:
+		bool compareString(const char* good, const char* str, uint8_t str_len) const;
+		std::vector<MqttCnx*>	clients;
+		WiFiServer server;
+
+		const char* auth_user = "guest";
+		const char* auth_password = "guest";
+};