Publish v2.8

Declare support for ESP32

.gitignore

@@ -1 +1,5 @@
 tests/bin
+.pioenvs
+.piolibdeps
+.clang_complete
+.gcc-flags.json

CHANGES.txt

@@ -1,3 +1,12 @@
+2.8
+   * Add setBufferSize() to override MQTT_MAX_PACKET_SIZE
+   * Add setKeepAlive() to override MQTT_KEEPALIVE
+   * Add setSocketTimeout() to overide MQTT_SOCKET_TIMEOUT
+   * Added check to prevent subscribe/unsubscribe to empty topics
+   * Declare wifi mode prior to connect in ESP example
+   * Use `strnlen` to avoid overruns
+   * Support pre-connected Client objects
+
 2.7
    * Fix remaining-length handling to prevent buffer overrun
    * Add large-payload API - beginPublish/write/publish/endPublish

LICENSE.txt

@@ -1,4 +1,4 @@
-Copyright (c) 2008-2015 Nicholas O'Leary
+Copyright (c) 2008-2020 Nicholas O'Leary
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

README.md

@@ -13,10 +13,12 @@ Full API documentation is available here: https://pubsubclient.knolleary.net
 ## Limitations
 
  - It can only publish QoS 0 messages. It can subscribe at QoS 0 or QoS 1.
- - The maximum message size, including header, is **128 bytes** by default. This
-   is configurable via `MQTT_MAX_PACKET_SIZE` in `PubSubClient.h`.
+ - The maximum message size, including header, is **256 bytes** by default. This
+   is configurable via `MQTT_MAX_PACKET_SIZE` in `PubSubClient.h` or can be changed
+   by calling `PubSubClient::setBufferSize(size)`.
  - The keepalive interval is set to 15 seconds by default. This is configurable
-   via `MQTT_KEEPALIVE` in `PubSubClient.h`.
+   via `MQTT_KEEPALIVE` in `PubSubClient.h` or can be changed by calling
+   `PubSubClient::setKeepAlive(keepAlive)`.
  - The client uses MQTT 3.1.1 by default. It can be changed to use MQTT 3.1 by
    changing value of `MQTT_VERSION` in `PubSubClient.h`.
 

examples/mqtt_auth/mqtt_auth.ino

@@ -27,9 +27,9 @@ void setup()
 {
   Ethernet.begin(mac, ip);
   // Note - the default maximum packet size is 128 bytes. If the
-  // combined length of clientId, username and password exceed this,
-  // you will need to increase the value of MQTT_MAX_PACKET_SIZE in
-  // PubSubClient.h
+  // combined length of clientId, username and password exceed this use the
+  // following to increase the buffer size:
+  // client.setBufferSize(255);
   
   if (client.connect("arduinoClient", "testuser", "testpass")) {
     client.publish("outTopic","hello world");

examples/mqtt_esp8266/mqtt_esp8266.ino

@@ -1,26 +1,21 @@
 /*
  Basic ESP8266 MQTT example
-
  This sketch demonstrates the capabilities of the pubsub library in combination
  with the ESP8266 board/library.
-
  It connects to an MQTT server then:
   - publishes "hello world" to the topic "outTopic" every two seconds
   - subscribes to the topic "inTopic", printing out any messages
     it receives. NB - it assumes the received payloads are strings not binary
   - If the first character of the topic "inTopic" is an 1, switch ON the ESP Led,
     else switch it off
-
  It will reconnect to the server if the connection is lost using a blocking
  reconnect function. See the 'mqtt_reconnect_nonblocking' example for how to
  achieve the same result without blocking the main loop.
-
  To install the ESP8266 board, (using Arduino 1.6.4+):
   - Add the following 3rd party board manager under "File -> Preferences -> Additional Boards Manager URLs":
        http://arduino.esp8266.com/stable/package_esp8266com_index.json
   - Open the "Tools -> Board -> Board Manager" and click install for the ESP8266"
   - Select your ESP8266 in "Tools -> Board"
-
 */
 
 #include <ESP8266WiFi.h>
@@ -34,8 +29,9 @@ const char* mqtt_server = "broker.mqtt-dashboard.com";
 
 WiFiClient espClient;
 PubSubClient client(espClient);
-long lastMsg = 0;
-char msg[50];
+unsigned long lastMsg = 0;
+#define MSG_BUFFER_SIZE	(50)
+char msg[MSG_BUFFER_SIZE];
 int value = 0;
 
 void setup_wifi() {
@@ -46,6 +42,7 @@ void setup_wifi() {
   Serial.print("Connecting to ");
   Serial.println(ssid);
 
+  WiFi.mode(WIFI_STA);
   WiFi.begin(ssid, password);
 
   while (WiFi.status() != WL_CONNECTED) {
@@ -120,11 +117,11 @@ void loop() {
   }
   client.loop();
 
-  long now = millis();
+  unsigned long now = millis();
   if (now - lastMsg > 2000) {
     lastMsg = now;
     ++value;
-    snprintf (msg, 50, "hello world #%ld", value);
+    snprintf (msg, MSG_BUFFER_SIZE, "hello world #%ld", value);
     Serial.print("Publish message: ");
     Serial.println(msg);
     client.publish("outTopic", msg);

keywords.txt

@@ -27,6 +27,9 @@ setServer	KEYWORD2
 setCallback	KEYWORD2
 setClient	KEYWORD2
 setStream	KEYWORD2
+setKeepAlive 	KEYWORD2
+setBufferSize 	KEYWORD2
+setSocketTimeout 	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)

library.json

@@ -6,12 +6,13 @@
         "type": "git",
         "url": "https://github.com/knolleary/pubsubclient.git"
     },
-    "version": "2.7",
+    "version": "2.8",
     "exclude": "tests",
     "examples": "examples/*/*.ino",
     "frameworks": "arduino",
     "platforms": [
         "atmelavr",
-        "espressif"
+        "espressif8266",
+        "espressif32"
     ]
 }

library.properties

@@ -1,5 +1,5 @@
 name=PubSubClient
-version=2.7
+version=2.8
 author=Nick O'Leary <nick.oleary@gmail.com>
 maintainer=Nick O'Leary <nick.oleary@gmail.com>
 sentence=A client library for MQTT messaging.

src/PubSubClient.cpp

@@ -1,4 +1,5 @@
 /*
+
   PubSubClient.cpp - A simple client for MQTT.
   Nick O'Leary
   http://knolleary.net
@@ -12,12 +13,20 @@ PubSubClient::PubSubClient() {
     this->_client = NULL;
     this->stream = NULL;
     setCallback(NULL);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 
 PubSubClient::PubSubClient(Client& client) {
     this->_state = MQTT_DISCONNECTED;
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 
 PubSubClient::PubSubClient(IPAddress addr, uint16_t port, Client& client) {
@@ -25,12 +34,20 @@ PubSubClient::PubSubClient(IPAddress addr, uint16_t port, Client& client) {
     setServer(addr, port);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(IPAddress addr, uint16_t port, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
     setServer(addr,port);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client) {
     this->_state = MQTT_DISCONNECTED;
@@ -38,6 +55,10 @@ PubSubClient::PubSubClient(IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATUR
     setCallback(callback);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
@@ -45,6 +66,10 @@ PubSubClient::PubSubClient(IPAddress addr, uint16_t port, MQTT_CALLBACK_SIGNATUR
     setCallback(callback);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 
 PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, Client& client) {
@@ -52,12 +77,20 @@ PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, Client& client) {
     setServer(ip, port);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
     setServer(ip,port);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client) {
     this->_state = MQTT_DISCONNECTED;
@@ -65,6 +98,10 @@ PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE,
     setCallback(callback);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
@@ -72,6 +109,10 @@ PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, MQTT_CALLBACK_SIGNATURE,
     setCallback(callback);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 
 PubSubClient::PubSubClient(const char* domain, uint16_t port, Client& client) {
@@ -79,12 +120,20 @@ PubSubClient::PubSubClient(const char* domain, uint16_t port, Client& client) {
     setServer(domain,port);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(const char* domain, uint16_t port, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
     setServer(domain,port);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(const char* domain, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client) {
     this->_state = MQTT_DISCONNECTED;
@@ -92,6 +141,10 @@ PubSubClient::PubSubClient(const char* domain, uint16_t port, MQTT_CALLBACK_SIGN
     setCallback(callback);
     setClient(client);
     this->stream = NULL;
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
 }
 PubSubClient::PubSubClient(const char* domain, uint16_t port, MQTT_CALLBACK_SIGNATURE, Client& client, Stream& stream) {
     this->_state = MQTT_DISCONNECTED;
@@ -99,6 +152,14 @@ PubSubClient::PubSubClient(const char* domain, uint16_t port, MQTT_CALLBACK_SIGN
     setCallback(callback);
     setClient(client);
     setStream(stream);
+    this->bufferSize = 0;
+    setBufferSize(MQTT_MAX_PACKET_SIZE);
+    setKeepAlive(MQTT_KEEPALIVE);
+    setSocketTimeout(MQTT_SOCKET_TIMEOUT);
+}
+
+PubSubClient::~PubSubClient() {
+  free(this->buffer);
 }
 
 boolean PubSubClient::connect(const char *id) {
@@ -121,11 +182,17 @@ boolean PubSubClient::connect(const char *id, const char *user, const char *pass
     if (!connected()) {
         int result = 0;
 
-        if (domain != NULL) {
-            result = _client->connect(this->domain, this->port);
+
+        if(_client->connected()) {
+            result = 1;
         } else {
-            result = _client->connect(this->ip, this->port);
+            if (domain != NULL) {
+                result = _client->connect(this->domain, this->port);
+            } else {
+                result = _client->connect(this->ip, this->port);
+            }
         }
+
         if (result == 1) {
             nextMsgId = 1;
             // Leave room in the buffer for header and variable length field
@@ -140,7 +207,7 @@ boolean PubSubClient::connect(const char *id, const char *user, const char *pass
 #define MQTT_HEADER_VERSION_LENGTH 7
 #endif
             for (j = 0;j<MQTT_HEADER_VERSION_LENGTH;j++) {
-                buffer[length++] = d[j];
+                this->buffer[length++] = d[j];
             }
 
             uint8_t v;
@@ -160,44 +227,43 @@ boolean PubSubClient::connect(const char *id, const char *user, const char *pass
                     v = v|(0x80>>1);
                 }
             }
+            this->buffer[length++] = v;
 
-            buffer[length++] = v;
-
-            buffer[length++] = ((MQTT_KEEPALIVE) >> 8);
-            buffer[length++] = ((MQTT_KEEPALIVE) & 0xFF);
+            this->buffer[length++] = ((this->keepAlive) >> 8);
+            this->buffer[length++] = ((this->keepAlive) & 0xFF);
 
             CHECK_STRING_LENGTH(length,id)
-            length = writeString(id,buffer,length);
+            length = writeString(id,this->buffer,length);
             if (willTopic) {
                 CHECK_STRING_LENGTH(length,willTopic)
-                length = writeString(willTopic,buffer,length);
+                length = writeString(willTopic,this->buffer,length);
                 CHECK_STRING_LENGTH(length,willMessage)
-                length = writeString(willMessage,buffer,length);
+                length = writeString(willMessage,this->buffer,length);
             }
 
             if(user != NULL) {
                 CHECK_STRING_LENGTH(length,user)
-                length = writeString(user,buffer,length);
+                length = writeString(user,this->buffer,length);
                 if(pass != NULL) {
                     CHECK_STRING_LENGTH(length,pass)
-                    length = writeString(pass,buffer,length);
+                    length = writeString(pass,this->buffer,length);
                 }
             }
 
-            write(MQTTCONNECT,buffer,length-MQTT_MAX_HEADER_SIZE);
+            write(MQTTCONNECT,this->buffer,length-MQTT_MAX_HEADER_SIZE);
 
             lastInActivity = lastOutActivity = millis();
 
             while (!_client->available()) {
                 unsigned long t = millis();
-                if (t-lastInActivity >= ((int32_t) MQTT_SOCKET_TIMEOUT*1000UL)) {
+                if (t-lastInActivity >= ((int32_t) this->socketTimeout*1000UL)) {
                     _state = MQTT_CONNECTION_TIMEOUT;
                     _client->stop();
                     return false;
                 }
             }
             uint8_t llen;
-            uint16_t len = readPacket(&llen);
+            uint32_t len = readPacket(&llen);
 
             if (len == 4) {
                 if (buffer[3] == 0) {
@@ -224,7 +290,7 @@ boolean PubSubClient::readByte(uint8_t * result) {
    while(!_client->available()) {
      yield();
      uint32_t currentMillis = millis();
-     if(currentMillis - previousMillis >= ((int32_t) MQTT_SOCKET_TIMEOUT * 1000)){
+     if(currentMillis - previousMillis >= ((int32_t) this->socketTimeout * 1000)){
        return false;
      }
    }
@@ -243,15 +309,15 @@ boolean PubSubClient::readByte(uint8_t * result, uint16_t * index){
   return false;
 }
 
-uint16_t PubSubClient::readPacket(uint8_t* lengthLength) {
+uint32_t PubSubClient::readPacket(uint8_t* lengthLength) {
     uint16_t len = 0;
-    if(!readByte(buffer, &len)) return 0;
-    bool isPublish = (buffer[0]&0xF0) == MQTTPUBLISH;
+    if(!readByte(this->buffer, &len)) return 0;
+    bool isPublish = (this->buffer[0]&0xF0) == MQTTPUBLISH;
     uint32_t multiplier = 1;
-    uint16_t length = 0;
+    uint32_t length = 0;
     uint8_t digit = 0;
     uint16_t skip = 0;
-    uint8_t start = 0;
+    uint32_t start = 0;
 
     do {
         if (len == 5) {
@@ -261,56 +327,58 @@ uint16_t PubSubClient::readPacket(uint8_t* lengthLength) {
             return 0;
         }
         if(!readByte(&digit)) return 0;
-        buffer[len++] = digit;
+        this->buffer[len++] = digit;
         length += (digit & 127) * multiplier;
-        multiplier *= 128;
+        multiplier <<=7; //multiplier *= 128
     } while ((digit & 128) != 0);
     *lengthLength = len-1;
 
     if (isPublish) {
         // Read in topic length to calculate bytes to skip over for Stream writing
-        if(!readByte(buffer, &len)) return 0;
-        if(!readByte(buffer, &len)) return 0;
-        skip = (buffer[*lengthLength+1]<<8)+buffer[*lengthLength+2];
+        if(!readByte(this->buffer, &len)) return 0;
+        if(!readByte(this->buffer, &len)) return 0;
+        skip = (this->buffer[*lengthLength+1]<<8)+this->buffer[*lengthLength+2];
         start = 2;
-        if (buffer[0]&MQTTQOS1) {
+        if (this->buffer[0]&MQTTQOS1) {
             // skip message id
             skip += 2;
         }
     }
+    uint32_t idx = len;
 
-    for (uint16_t i = start;i<length;i++) {
+    for (uint32_t i = start;i<length;i++) {
         if(!readByte(&digit)) return 0;
         if (this->stream) {
-            if (isPublish && len-*lengthLength-2>skip) {
+            if (isPublish && idx-*lengthLength-2>skip) {
                 this->stream->write(digit);
             }
         }
-        if (len < MQTT_MAX_PACKET_SIZE) {
-            buffer[len] = digit;
+
+        if (len < this->bufferSize) {
+            this->buffer[len] = digit;
+            len++;
         }
-        len++;
+        idx++;
     }
 
-    if (!this->stream && len > MQTT_MAX_PACKET_SIZE) {
+    if (!this->stream && idx > this->bufferSize) {
         len = 0; // This will cause the packet to be ignored.
     }
-
     return len;
 }
 
 boolean PubSubClient::loop() {
     if (connected()) {
         unsigned long t = millis();
-        if ((t - lastInActivity > MQTT_KEEPALIVE*1000UL) || (t - lastOutActivity > MQTT_KEEPALIVE*1000UL)) {
+        if ((t - lastInActivity > this->keepAlive*1000UL) || (t - lastOutActivity > this->keepAlive*1000UL)) {
             if (pingOutstanding) {
                 this->_state = MQTT_CONNECTION_TIMEOUT;
                 _client->stop();
                 return false;
             } else {
-                buffer[0] = MQTTPINGREQ;
-                buffer[1] = 0;
-                _client->write(buffer,2);
+                this->buffer[0] = MQTTPINGREQ;
+                this->buffer[1] = 0;
+                _client->write(this->buffer,2);
                 lastOutActivity = t;
                 lastInActivity = t;
                 pingOutstanding = true;
@@ -323,35 +391,35 @@ boolean PubSubClient::loop() {
             uint8_t *payload;
             if (len > 0) {
                 lastInActivity = t;
-                uint8_t type = buffer[0]&0xF0;
+                uint8_t type = this->buffer[0]&0xF0;
                 if (type == MQTTPUBLISH) {
                     if (callback) {
-                        uint16_t tl = (buffer[llen+1]<<8)+buffer[llen+2]; /* topic length in bytes */
-                        memmove(buffer+llen+2,buffer+llen+3,tl); /* move topic inside buffer 1 byte to front */
-                        buffer[llen+2+tl] = 0; /* end the topic as a 'C' string with \x00 */
-                        char *topic = (char*) buffer+llen+2;
+                        uint16_t tl = (this->buffer[llen+1]<<8)+this->buffer[llen+2]; /* topic length in bytes */
+                        memmove(this->buffer+llen+2,this->buffer+llen+3,tl); /* move topic inside buffer 1 byte to front */
+                        this->buffer[llen+2+tl] = 0; /* end the topic as a 'C' string with \x00 */
+                        char *topic = (char*) this->buffer+llen+2;
                         // msgId only present for QOS>0
-                        if ((buffer[0]&0x06) == MQTTQOS1) {
-                            msgId = (buffer[llen+3+tl]<<8)+buffer[llen+3+tl+1];
-                            payload = buffer+llen+3+tl+2;
+                        if ((this->buffer[0]&0x06) == MQTTQOS1) {
+                            msgId = (this->buffer[llen+3+tl]<<8)+this->buffer[llen+3+tl+1];
+                            payload = this->buffer+llen+3+tl+2;
                             callback(topic,payload,len-llen-3-tl-2);
 
-                            buffer[0] = MQTTPUBACK;
-                            buffer[1] = 2;
-                            buffer[2] = (msgId >> 8);
-                            buffer[3] = (msgId & 0xFF);
-                            _client->write(buffer,4);
+                            this->buffer[0] = MQTTPUBACK;
+                            this->buffer[1] = 2;
+                            this->buffer[2] = (msgId >> 8);
+                            this->buffer[3] = (msgId & 0xFF);
+                            _client->write(this->buffer,4);
                             lastOutActivity = t;
 
                         } else {
-                            payload = buffer+llen+3+tl;
+                            payload = this->buffer+llen+3+tl;
                             callback(topic,payload,len-llen-3-tl);
                         }
                     }
                 } else if (type == MQTTPINGREQ) {
-                    buffer[0] = MQTTPINGRESP;
-                    buffer[1] = 0;
-                    _client->write(buffer,2);
+                    this->buffer[0] = MQTTPINGRESP;
+                    this->buffer[1] = 0;
+                    _client->write(this->buffer,2);
                 } else if (type == MQTTPINGRESP) {
                     pingOutstanding = false;
                 }
@@ -366,11 +434,11 @@ boolean PubSubClient::loop() {
 }
 
 boolean PubSubClient::publish(const char* topic, const char* payload) {
-    return publish(topic,(const uint8_t*)payload,strlen(payload),false);
+    return publish(topic,(const uint8_t*)payload, payload ? strnlen(payload, this->bufferSize) : 0,false);
 }
 
 boolean PubSubClient::publish(const char* topic, const char* payload, boolean retained) {
-    return publish(topic,(const uint8_t*)payload,strlen(payload),retained);
+    return publish(topic,(const uint8_t*)payload, payload ? strnlen(payload, this->bufferSize) : 0,retained);
 }
 
 boolean PubSubClient::publish(const char* topic, const uint8_t* payload, unsigned int plength) {
@@ -379,28 +447,32 @@ boolean PubSubClient::publish(const char* topic, const uint8_t* payload, unsigne
 
 boolean PubSubClient::publish(const char* topic, const uint8_t* payload, unsigned int plength, boolean retained) {
     if (connected()) {
-        if (MQTT_MAX_PACKET_SIZE < MQTT_MAX_HEADER_SIZE + 2+strlen(topic) + plength) {
+        if (this->bufferSize < MQTT_MAX_HEADER_SIZE + 2+strnlen(topic, this->bufferSize) + plength) {
             // Too long
             return false;
         }
         // Leave room in the buffer for header and variable length field
         uint16_t length = MQTT_MAX_HEADER_SIZE;
-        length = writeString(topic,buffer,length);
+        length = writeString(topic,this->buffer,length);
+
+        // Add payload
         uint16_t i;
         for (i=0;i<plength;i++) {
-            buffer[length++] = payload[i];
+            this->buffer[length++] = payload[i];
         }
+
+        // Write the header
         uint8_t header = MQTTPUBLISH;
         if (retained) {
             header |= 1;
         }
-        return write(header,buffer,length-MQTT_MAX_HEADER_SIZE);
+        return write(header,this->buffer,length-MQTT_MAX_HEADER_SIZE);
     }
     return false;
 }
 
 boolean PubSubClient::publish_P(const char* topic, const char* payload, boolean retained) {
-    return publish_P(topic, (const uint8_t*)payload, strlen(payload), retained);
+    return publish_P(topic, (const uint8_t*)payload, payload ? strnlen(payload, this->bufferSize) : 0, retained);
 }
 
 boolean PubSubClient::publish_P(const char* topic, const uint8_t* payload, unsigned int plength, boolean retained) {
@@ -412,32 +484,33 @@ boolean PubSubClient::publish_P(const char* topic, const uint8_t* payload, unsig
     unsigned int i;
     uint8_t header;
     unsigned int len;
+    int expectedLength;
 
     if (!connected()) {
         return false;
     }
 
-    tlen = strlen(topic);
+    tlen = strnlen(topic, this->bufferSize);
 
     header = MQTTPUBLISH;
     if (retained) {
         header |= 1;
     }
-    buffer[pos++] = header;
+    this->buffer[pos++] = header;
     len = plength + 2 + tlen;
     do {
-        digit = len % 128;
-        len = len / 128;
+        digit = len  & 127; //digit = len %128
+        len >>= 7; //len = len / 128
         if (len > 0) {
             digit |= 0x80;
         }
-        buffer[pos++] = digit;
+        this->buffer[pos++] = digit;
         llen++;
     } while(len>0);
 
-    pos = writeString(topic,buffer,pos);
+    pos = writeString(topic,this->buffer,pos);
 
-    rc += _client->write(buffer,pos);
+    rc += _client->write(this->buffer,pos);
 
     for (i=0;i<plength;i++) {
         rc += _client->write((char)pgm_read_byte_near(payload + i));
@@ -445,21 +518,22 @@ boolean PubSubClient::publish_P(const char* topic, const uint8_t* payload, unsig
 
     lastOutActivity = millis();
 
-    return rc == tlen + 4 + plength;
+    expectedLength = 1 + llen + 2 + tlen + plength;
+
+    return (rc == expectedLength);
 }
 
 boolean PubSubClient::beginPublish(const char* topic, unsigned int plength, boolean retained) {
     if (connected()) {
         // Send the header and variable length field
         uint16_t length = MQTT_MAX_HEADER_SIZE;
-        length = writeString(topic,buffer,length);
-        uint16_t i;
+        length = writeString(topic,this->buffer,length);
         uint8_t header = MQTTPUBLISH;
         if (retained) {
             header |= 1;
         }
-        size_t hlen = buildHeader(header, buffer, plength+length-MQTT_MAX_HEADER_SIZE);
-        uint16_t rc = _client->write(buffer+(MQTT_MAX_HEADER_SIZE-hlen),length-(MQTT_MAX_HEADER_SIZE-hlen));
+        size_t hlen = buildHeader(header, this->buffer, plength+length-MQTT_MAX_HEADER_SIZE);
+        uint16_t rc = _client->write(this->buffer+(MQTT_MAX_HEADER_SIZE-hlen),length-(MQTT_MAX_HEADER_SIZE-hlen));
         lastOutActivity = millis();
         return (rc == (length-(MQTT_MAX_HEADER_SIZE-hlen)));
     }
@@ -487,8 +561,9 @@ size_t PubSubClient::buildHeader(uint8_t header, uint8_t* buf, uint16_t length)
     uint8_t pos = 0;
     uint16_t len = length;
     do {
-        digit = len % 128;
-        len = len / 128;
+
+        digit = len  & 127; //digit = len %128
+        len >>= 7; //len = len / 128
         if (len > 0) {
             digit |= 0x80;
         }
@@ -532,10 +607,14 @@ boolean PubSubClient::subscribe(const char* topic) {
 }
 
 boolean PubSubClient::subscribe(const char* topic, uint8_t qos) {
+    size_t topicLength = strnlen(topic, this->bufferSize);
+    if (topic == 0) {
+        return false;
+    }
     if (qos > 1) {
         return false;
     }
-    if (MQTT_MAX_PACKET_SIZE < 9 + strlen(topic)) {
+    if (this->bufferSize < 9 + topicLength) {
         // Too long
         return false;
     }
@@ -546,17 +625,21 @@ boolean PubSubClient::subscribe(const char* topic, uint8_t qos) {
         if (nextMsgId == 0) {
             nextMsgId = 1;
         }
-        buffer[length++] = (nextMsgId >> 8);
-        buffer[length++] = (nextMsgId & 0xFF);
-        length = writeString((char*)topic, buffer,length);
-        buffer[length++] = qos;
-        return write(MQTTSUBSCRIBE|MQTTQOS1,buffer,length-MQTT_MAX_HEADER_SIZE);
+        this->buffer[length++] = (nextMsgId >> 8);
+        this->buffer[length++] = (nextMsgId & 0xFF);
+        length = writeString((char*)topic, this->buffer,length);
+        this->buffer[length++] = qos;
+        return write(MQTTSUBSCRIBE|MQTTQOS1,this->buffer,length-MQTT_MAX_HEADER_SIZE);
     }
     return false;
 }
 
 boolean PubSubClient::unsubscribe(const char* topic) {
-    if (MQTT_MAX_PACKET_SIZE < 9 + strlen(topic)) {
+	size_t topicLength = strnlen(topic, this->bufferSize);
+    if (topic == 0) {
+        return false;
+    }
+    if (this->bufferSize < 9 + topicLength) {
         // Too long
         return false;
     }
@@ -566,18 +649,18 @@ boolean PubSubClient::unsubscribe(const char* topic) {
         if (nextMsgId == 0) {
             nextMsgId = 1;
         }
-        buffer[length++] = (nextMsgId >> 8);
-        buffer[length++] = (nextMsgId & 0xFF);
-        length = writeString(topic, buffer,length);
-        return write(MQTTUNSUBSCRIBE|MQTTQOS1,buffer,length-MQTT_MAX_HEADER_SIZE);
+        this->buffer[length++] = (nextMsgId >> 8);
+        this->buffer[length++] = (nextMsgId & 0xFF);
+        length = writeString(topic, this->buffer,length);
+        return write(MQTTUNSUBSCRIBE|MQTTQOS1,this->buffer,length-MQTT_MAX_HEADER_SIZE);
     }
     return false;
 }
 
 void PubSubClient::disconnect() {
-    buffer[0] = MQTTDISCONNECT;
-    buffer[1] = 0;
-    _client->write(buffer,2);
+    this->buffer[0] = MQTTDISCONNECT;
+    this->buffer[1] = 0;
+    _client->write(this->buffer,2);
     _state = MQTT_DISCONNECTED;
     _client->flush();
     _client->stop();
@@ -610,6 +693,8 @@ boolean PubSubClient::connected() {
                 _client->flush();
                 _client->stop();
             }
+        } else {
+            return this->_state == MQTT_CONNECTED;
         }
     }
     return rc;
@@ -651,3 +736,34 @@ PubSubClient& PubSubClient::setStream(Stream& stream){
 int PubSubClient::state() {
     return this->_state;
 }
+
+boolean PubSubClient::setBufferSize(uint16_t size) {
+    if (size == 0) {
+        // Cannot set it back to 0
+        return false;
+    }
+    if (this->bufferSize == 0) {
+        this->buffer = (uint8_t*)malloc(size);
+    } else {
+        uint8_t* newBuffer = (uint8_t*)realloc(this->buffer, size);
+        if (newBuffer != NULL) {
+            this->buffer = newBuffer;
+        } else {
+            return false;
+        }
+    }
+    this->bufferSize = size;
+    return (this->buffer != NULL);
+}
+
+uint16_t PubSubClient::getBufferSize() {
+    return this->bufferSize;
+}
+PubSubClient& PubSubClient::setKeepAlive(uint16_t keepAlive) {
+    this->keepAlive = keepAlive;
+    return *this;
+}
+PubSubClient& PubSubClient::setSocketTimeout(uint16_t timeout) {
+    this->socketTimeout = timeout;
+    return *this;
+}

src/PubSubClient.h

@@ -21,17 +21,17 @@
 #define MQTT_VERSION MQTT_VERSION_3_1_1
 #endif
 
-// MQTT_MAX_PACKET_SIZE : Maximum packet size
+// MQTT_MAX_PACKET_SIZE : Maximum packet size. Override with setBufferSize().
 #ifndef MQTT_MAX_PACKET_SIZE
-#define MQTT_MAX_PACKET_SIZE 128
+#define MQTT_MAX_PACKET_SIZE 256
 #endif
 
-// MQTT_KEEPALIVE : keepAlive interval in Seconds
+// MQTT_KEEPALIVE : keepAlive interval in Seconds. Override with setKeepAlive()
 #ifndef MQTT_KEEPALIVE
 #define MQTT_KEEPALIVE 15
 #endif
 
-// MQTT_SOCKET_TIMEOUT: socket timeout interval in Seconds
+// MQTT_SOCKET_TIMEOUT: socket timeout interval in Seconds. Override with setSocketTimeout()
 #ifndef MQTT_SOCKET_TIMEOUT
 #define MQTT_SOCKET_TIMEOUT 15
 #endif
@@ -83,18 +83,21 @@
 #define MQTT_CALLBACK_SIGNATURE void (*callback)(char*, uint8_t*, unsigned int)
 #endif
 
-#define CHECK_STRING_LENGTH(l,s) if (l+2+strlen(s) > MQTT_MAX_PACKET_SIZE) {_client->stop();return false;}
+#define CHECK_STRING_LENGTH(l,s) if (l+2+strnlen(s, this->bufferSize) > this->bufferSize) {_client->stop();return false;}
 
 class PubSubClient : public Print {
 private:
    Client* _client;
-   uint8_t buffer[MQTT_MAX_PACKET_SIZE];
+   uint8_t* buffer;
+   uint16_t bufferSize;
+   uint16_t keepAlive;
+   uint16_t socketTimeout;
    uint16_t nextMsgId;
    unsigned long lastOutActivity;
    unsigned long lastInActivity;
    bool pingOutstanding;
    MQTT_CALLBACK_SIGNATURE;
-   uint16_t readPacket(uint8_t*);
+   uint32_t readPacket(uint8_t*);
    boolean readByte(uint8_t * result);
    boolean readByte(uint8_t * result, uint16_t * index);
    boolean write(uint8_t header, uint8_t* buf, uint16_t length);
@@ -125,12 +128,19 @@ public:
    PubSubClient(const char*, uint16_t, MQTT_CALLBACK_SIGNATURE,Client& client);
    PubSubClient(const char*, uint16_t, MQTT_CALLBACK_SIGNATURE,Client& client, Stream&);
 
+   ~PubSubClient();
+
    PubSubClient& setServer(IPAddress ip, uint16_t port);
    PubSubClient& setServer(uint8_t * ip, uint16_t port);
    PubSubClient& setServer(const char * domain, uint16_t port);
    PubSubClient& setCallback(MQTT_CALLBACK_SIGNATURE);
    PubSubClient& setClient(Client& client);
    PubSubClient& setStream(Stream& stream);
+   PubSubClient& setKeepAlive(uint16_t keepAlive);
+   PubSubClient& setSocketTimeout(uint16_t timeout);
+
+   boolean setBufferSize(uint16_t size);
+   uint16_t getBufferSize();
 
    boolean connect(const char* id);
    boolean connect(const char* id, const char* user, const char* pass);
@@ -167,6 +177,7 @@ public:
    boolean loop();
    boolean connected();
    int state();
+
 };
 
 

tests/src/connect_spec.cpp

@@ -280,6 +280,38 @@ int test_connect_disconnect_connect() {
     END_IT
 }
 
+int test_connect_custom_keepalive() {
+    IT("sends a properly formatted connect packet with custom keepalive value");
+    ShimClient shimClient;
+
+    shimClient.setAllowConnect(true);
+    byte expectServer[] = { 172, 16, 0, 2 };
+    shimClient.expectConnect(expectServer,1883);
+
+    // Set keepalive to 300secs == 0x01 0x2c
+    byte connect[] = {0x10,0x18,0x0,0x4,0x4d,0x51,0x54,0x54,0x4,0x2,0x01,0x2c,0x0,0xc,0x63,0x6c,0x69,0x65,0x6e,0x74,0x5f,0x74,0x65,0x73,0x74,0x31};
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+
+    shimClient.expect(connect,26);
+    shimClient.respond(connack,4);
+
+    PubSubClient client(server, 1883, callback, shimClient);
+    int state = client.state();
+    IS_TRUE(state == MQTT_DISCONNECTED);
+
+    client.setKeepAlive(300);
+
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+    IS_FALSE(shimClient.error());
+
+    state = client.state();
+    IS_TRUE(state == MQTT_CONNECTED);
+
+    END_IT
+}
+
+
 int main()
 {
     SUITE("Connect");
@@ -298,5 +330,7 @@ int main()
     test_connect_with_will();
     test_connect_with_will_username_password();
     test_connect_disconnect_connect();
+
+    test_connect_custom_keepalive();
     FINISH
 }

tests/src/lib/Buffer.h

@@ -5,18 +5,18 @@
 
 class Buffer {
 private:
-    uint8_t buffer[1024];
+    uint8_t buffer[2048];
     uint16_t pos;
     uint16_t length;
-    
+
 public:
     Buffer();
     Buffer(uint8_t* buf, size_t size);
-    
+
     virtual bool available();
     virtual uint8_t next();
     virtual void reset();
-    
+
     virtual void add(uint8_t* buf, size_t size);
 };
 

tests/src/publish_spec.cpp

@@ -134,6 +134,7 @@ int test_publish_too_long() {
     shimClient.respond(connack,4);
 
     PubSubClient client(server, 1883, callback, shimClient);
+    client.setBufferSize(128);
     int rc = client.connect((char*)"client_test1");
     IS_TRUE(rc);
 

tests/src/receive_spec.cpp

@@ -20,6 +20,7 @@ void reset_callback() {
 }
 
 void callback(char* topic, byte* payload, unsigned int length) {
+    TRACE("Callback received topic=[" << topic << "] length=" << length << "\n")
     callback_called = true;
     strcpy(lastTopic,topic);
     memcpy(lastPayload,payload,length);
@@ -102,10 +103,15 @@ int test_receive_max_sized_message() {
     shimClient.respond(connack,4);
 
     PubSubClient client(server, 1883, callback, shimClient);
+    int length = 80; // If this is changed to > 128 then the publish packet below
+                     // is no longer valid as it assumes the remaining length
+                     // is a single-byte. Don't make that mistake like I just
+                     // did and lose a whole evening tracking down the issue.
+    client.setBufferSize(length);
     int rc = client.connect((char*)"client_test1");
     IS_TRUE(rc);
 
-    int length = MQTT_MAX_PACKET_SIZE;
+
     byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
     byte bigPublish[length];
     memset(bigPublish,'A',length);
@@ -137,11 +143,13 @@ int test_receive_oversized_message() {
     byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
     shimClient.respond(connack,4);
 
+    int length = 80; // See comment in test_receive_max_sized_message before changing this value
+
     PubSubClient client(server, 1883, callback, shimClient);
+    client.setBufferSize(length-1);
     int rc = client.connect((char*)"client_test1");
     IS_TRUE(rc);
 
-    int length = MQTT_MAX_PACKET_SIZE+1;
     byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
     byte bigPublish[length];
     memset(bigPublish,'A',length);
@@ -188,9 +196,58 @@ int test_drop_invalid_remaining_length_message() {
     END_IT
 }
 
+int test_resize_buffer() {
+    IT("receives a message larger than the default maximum");
+    reset_callback();
+
+    ShimClient shimClient;
+    shimClient.setAllowConnect(true);
+
+    byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
+    shimClient.respond(connack,4);
+
+    int length = 80; // See comment in test_receive_max_sized_message before changing this value
+
+    PubSubClient client(server, 1883, callback, shimClient);
+    client.setBufferSize(length-1);
+    int rc = client.connect((char*)"client_test1");
+    IS_TRUE(rc);
+
+    byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
+    byte bigPublish[length];
+    memset(bigPublish,'A',length);
+    bigPublish[length] = 'B';
+    memcpy(bigPublish,publish,16);
+    // Send it twice
+    shimClient.respond(bigPublish,length);
+    shimClient.respond(bigPublish,length);
+
+    rc = client.loop();
+    IS_TRUE(rc);
+
+    // First message fails as it is too big
+    IS_FALSE(callback_called);
+
+    // Resize the buffer
+    client.setBufferSize(length);
+
+    rc = client.loop();
+    IS_TRUE(rc);
+
+    IS_TRUE(callback_called);
+
+    IS_TRUE(strcmp(lastTopic,"topic")==0);
+    IS_TRUE(lastLength == length-9);
+    IS_TRUE(memcmp(lastPayload,bigPublish+9,lastLength)==0);
+
+    IS_FALSE(shimClient.error());
+
+    END_IT
+}
+
 
 int test_receive_oversized_stream_message() {
-    IT("drops an oversized message");
+    IT("receive an oversized streamed message");
     reset_callback();
 
     Stream stream;
@@ -201,11 +258,13 @@ int test_receive_oversized_stream_message() {
     byte connack[] = { 0x20, 0x02, 0x00, 0x00 };
     shimClient.respond(connack,4);
 
+    int length = 80; // See comment in test_receive_max_sized_message before changing this value
+
     PubSubClient client(server, 1883, callback, shimClient, stream);
+    client.setBufferSize(length-1);
     int rc = client.connect((char*)"client_test1");
     IS_TRUE(rc);
 
-    int length = MQTT_MAX_PACKET_SIZE+1;
     byte publish[] = {0x30,length-2,0x0,0x5,0x74,0x6f,0x70,0x69,0x63,0x70,0x61,0x79,0x6c,0x6f,0x61,0x64};
 
     byte bigPublish[length];
@@ -222,7 +281,8 @@ int test_receive_oversized_stream_message() {
 
     IS_TRUE(callback_called);
     IS_TRUE(strcmp(lastTopic,"topic")==0);
-    IS_TRUE(lastLength == length-9);
+
+    IS_TRUE(lastLength == length-10);
 
     IS_FALSE(stream.error());
     IS_FALSE(shimClient.error());
@@ -272,6 +332,7 @@ int main()
     test_receive_max_sized_message();
     test_drop_invalid_remaining_length_message();
     test_receive_oversized_message();
+    test_resize_buffer();
     test_receive_oversized_stream_message();
     test_receive_qos1();
 

tests/src/subscribe_spec.cpp

@@ -106,6 +106,7 @@ int test_subscribe_too_long() {
     shimClient.respond(connack,4);
 
     PubSubClient client(server, 1883, callback, shimClient);
+    client.setBufferSize(128);
     int rc = client.connect((char*)"client_test1");
     IS_TRUE(rc);