Added support for mqtt over websockets

This feature will only be compiled if explicitly enabled:
qmake CONFIG+=QMQTT_WEBSOCKETS
or:
qbs build qmqtt.webSocketSupport:true

There are 2 reasons:
* websocket support relies on the QWebsocket class which is
  part of the websockets module. Previous versions of qmqtt
  did not rely on this module, so it may not be present on
  systems where old versions of the shared library are in use.
  Adding a new module dependency will make it harder to upgrade
  this systems.
* A call to QWebSocket::open(const QNetworkRequest &) is used,
  which was introduced in Qt 5.6. qmqtt itself requires version
  5.3 or newer.

.travis.yml

@@ -1,10 +1,15 @@
+language: cpp
+compiler:
+ - gcc
+
 before_install:
  - sudo apt-add-repository -y ppa:ubuntu-toolchain-r/test
- - sudo apt-add-repository -y ppa:beineri/opt-qt56
+ - sudo apt-add-repository -y ppa:beineri/opt-qt571-trusty
  - sudo apt-get update -qq
- - sudo apt-get install -qq qt56base qt56tools g++-4.8
- - source /opt/qt56/bin/qt56-env.sh
- - export CXX="g++-4.8"
+ - sudo apt-get install -qq qt57base qt57tools qt57websockets g++-5
+ - source /opt/qt57/bin/qt57-env.sh
+ - export CXX="g++-5"
+ - export CC="gcc-5"
 
 script:
  - qmake --version

README.md

@@ -5,6 +5,8 @@ mqtt client for Qt
 
 **Please compile the library with Qt >= 5.3 version. On Windows you need to specify `CONFIG += NO_UNIT_TESTS`, since gtest is not supported.**
 
+To add websocket support, compile the library with Qt >= 5.7, and specify 'CONFIG += QMQTT_WEBSOCKETS'.
+
 Usage
 =====
 
@@ -26,6 +28,14 @@ Connect using ssl:
     client->setPassword("password");
     client->connectToHost();
 
+Connect using websockets:
+
+    QMQTT::Client *client = new QMQTT::Client("ws://www.example.com/mqtt", "<origin>", QWebSocketProtocol::VersionLatest);
+    client->setClientId("clientId");
+    client->setUsername("user");
+    client->setPassword("password");
+    client->connectToHost();
+
 Slots
 =====
 

src/mqtt/mqtt.pri

@@ -17,7 +17,9 @@ PRIVATE_HEADERS += \
     $$PWD/qmqtt_network_p.h \
     $$PWD/qmqtt_socket_p.h \
     $$PWD/qmqtt_ssl_socket_p.h \
-    $$PWD/qmqtt_timer_p.h
+    $$PWD/qmqtt_timer_p.h \
+    $$PWD/qmqtt_websocket_p.h \
+    $$PWD/qmqtt_websocketiodevice_p.h
 
 SOURCES += \
     $$PWD/qmqtt_client_p.cpp \
@@ -30,4 +32,6 @@ SOURCES += \
     $$PWD/qmqtt_message_p.cpp \
     $$PWD/qmqtt_socket.cpp \
     $$PWD/qmqtt_ssl_socket.cpp \
-    $$PWD/qmqtt_timer.cpp
+    $$PWD/qmqtt_timer.cpp \
+    $$PWD/qmqtt_websocket.cpp \
+    $$PWD/qmqtt_websocketiodevice.cpp

src/mqtt/mqtt.pro

@@ -1,5 +1,6 @@
 TARGET = qmqtt
 QT = core network
+QMQTT_WEBSOCKETS: QT += websockets
 
 DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
 

src/mqtt/mqtt.qbs

@@ -7,6 +7,7 @@ Product {
         libraryType,
         "mqttmodule",
     ]
+    property bool webSocketSupport: false
     property string libraryType: "dynamiclibrary"
     targetName: "qmqtt"
 
@@ -87,10 +88,16 @@ Product {
 
     Depends {
         name: "Qt"
-        submodules: [
-            "core",
-            "network",
-        ]
+        property var baseModules: ["core", "network"]
+
+        Properties {
+            condition: webSocketSupport
+            submodules: baseModules.concat(["websockets"])
+        }
+        Properties {
+            condition: !webSocketSupport
+            submodules: baseModules
+        }
     }
 
     Export {
@@ -100,10 +107,15 @@ Product {
 
         Depends {
             name: "Qt"
-            submodules: [
-                "core",
-                "network",
-            ]
+            property var baseModules: ["core", "network"]
+            Properties {
+                condition: product.webSocketSupport
+                submodules: baseModules.concat(["websockets"])
+            }
+            Properties {
+                condition: !product.webSocketSupport
+                submodules: baseModules
+            }
         }
 
         cpp.includePaths: product.sourceDirectory

src/mqtt/qmqtt_client.cpp

@@ -68,6 +68,20 @@ QMQTT::Client::Client(const QString &hostName,
     d->init(hostName, port, ssl, ignoreSelfSigned);
 }
 
+#ifdef QT_WEBSOCKETS_LIB
+QMQTT::Client::Client(const QString& url,
+                      const QString& origin,
+                      QWebSocketProtocol::Version version,
+                      bool ignoreSelfSigned,
+                      QObject* parent)
+    : QObject(parent)
+    , d_ptr(new ClientPrivate(this))
+{
+    Q_D(Client);
+    d->init(url, origin, version, ignoreSelfSigned);
+}
+#endif // QT_WEBSOCKETS_LIB
+
 QMQTT::Client::Client(NetworkInterface* network,
                       const QHostAddress& host,
                       const quint16 port,

src/mqtt/qmqtt_client.h

@@ -39,6 +39,10 @@
 #include <QScopedPointer>
 #include <QHostAddress>
 
+#ifdef QT_WEBSOCKETS_LIB
+#include <QWebSocket>
+#endif // QT_WEBSOCKETS_LIB
+
 #ifndef QT_NO_SSL
 QT_FORWARD_DECLARE_CLASS(QSslConfiguration)
 #endif // QT_NO_SSL
@@ -140,6 +144,15 @@ class Q_MQTT_EXPORT Client : public QObject
            const bool ignoreSelfSigned,
            QObject* parent = NULL);
 
+#ifdef QT_WEBSOCKETS_LIB
+    // Create a connection over websockets
+    Client(const QString& url,
+           const QString& origin,
+           QWebSocketProtocol::Version version,
+           bool ignoreSelfSigned = false,
+           QObject* parent = NULL);
+#endif // QT_WEBSOCKETS_LIB
+
     // for testing purposes only
     Client(NetworkInterface* network,
            const QHostAddress& host = QHostAddress::LocalHost,

src/mqtt/qmqtt_client_p.cpp

@@ -118,6 +118,15 @@ void QMQTT::ClientPrivate::init(const QString& hostName, const quint16 port, con
     }
 }
 
+#ifdef QT_WEBSOCKETS_LIB
+void QMQTT::ClientPrivate::init(const QString& url, const QString& origin,
+                                QWebSocketProtocol::Version version, bool ignoreSelfSigned)
+{
+    _hostName = url;
+    init(new Network(origin, version, ignoreSelfSigned));
+}
+#endif // QT_WEBSOCKETS_LIB
+
 void QMQTT::ClientPrivate::init(NetworkInterface* network)
 {
     Q_Q(Client);

src/mqtt/qmqtt_client_p.h

@@ -37,6 +37,10 @@
 #include "qmqtt_network_p.h"
 #include <QTimer>
 
+#ifdef QT_WEBSOCKETS_LIB
+#include <QWebSocket>
+#endif // QT_WEBSOCKETS_LIB
+
 #ifndef QT_NO_SSL
 QT_FORWARD_DECLARE_CLASS(QSslConfiguration)
 #endif // QT_NO_SSL
@@ -55,11 +59,18 @@ class ClientPrivate
               const bool ignoreSelfSigned=false);
 #endif // QT_NO_SSL
     void init(const QString& hostName, const quint16 port, const bool ssl, const bool ignoreSelfSigned);
+#ifdef QT_WEBSOCKETS_LIB
+    void init(const QString& url, const QString &origin, QWebSocketProtocol::Version version,
+              bool ignoreSelfSigned);
+#endif // QT_WEBSOCKETS_LIB
     void init(NetworkInterface* network);
 
     QHostAddress _host;
     QString _hostName;
     quint16 _port;
+#ifdef QT_WEBSOCKETS_LIB
+    QWebSocketProtocol::Version _webSocketVersion;
+#endif // QT_WEBSOCKETS_LIB
     quint16 _gmid;
     MQTTVersion _version;
     QString _clientId;

src/mqtt/qmqtt_network.cpp

@@ -34,6 +34,7 @@
 #include "qmqtt_socket_p.h"
 #include "qmqtt_ssl_socket_p.h"
 #include "qmqtt_timer_p.h"
+#include "qmqtt_websocket_p.h"
 
 const QString DEFAULT_HOST_NAME = QStringLiteral("localhost");
 const QHostAddress DEFAULT_HOST = QHostAddress::LocalHost;
@@ -70,6 +71,22 @@ QMQTT::Network::Network(const QSslConfiguration &config, bool ignoreSelfSigned,
 }
 #endif // QT_NO_SSL
 
+#ifdef QT_WEBSOCKETS_LIB
+QMQTT::Network::Network(const QString& origin, QWebSocketProtocol::Version version,
+                        bool ignoreSelfSigned, QObject* parent)
+    : NetworkInterface(parent)
+    , _port(DEFAULT_SSL_PORT)
+    , _hostName(DEFAULT_HOST_NAME)
+    , _autoReconnect(DEFAULT_AUTORECONNECT)
+    , _autoReconnectInterval(DEFAULT_AUTORECONNECT_INTERVAL_MS)
+    , _socket(new QMQTT::WebSocket(origin, version, ignoreSelfSigned))
+    , _autoReconnectTimer(new QMQTT::Timer)
+    , _readState(Header)
+{
+    initialize();
+}
+#endif // QT_WEBSOCKETS_LIB
+
 QMQTT::Network::Network(SocketInterface* socketInterface, TimerInterface* timerInterface,
                         QObject* parent)
     : NetworkInterface(parent)

src/mqtt/qmqtt_network_p.h

@@ -40,6 +40,10 @@
 #include <QByteArray>
 #include <QHostAddress>
 
+#ifdef QT_WEBSOCKETS_LIB
+#include <QWebSocket>
+#endif // QT_WEBSOCKETS_LIB
+
 #ifndef QT_NO_SSL
 QT_FORWARD_DECLARE_CLASS(QSslConfiguration)
 #endif // QT_NO_SSL
@@ -58,6 +62,10 @@ class Network : public NetworkInterface
 #ifndef QT_NO_SSL
     Network(const QSslConfiguration& config, bool ignoreSelfSigned, QObject* parent = NULL);
 #endif // QT_NO_SSL
+#ifdef QT_WEBSOCKETS_LIB
+    Network(const QString& origin, QWebSocketProtocol::Version version, bool ignoreSelfSigned,
+            QObject* parent = NULL);
+#endif // QT_WEBSOCKETS_LIB
     Network(SocketInterface* socketInterface, TimerInterface* timerInterface,
             QObject* parent = NULL);
     ~Network();

src/mqtt/qmqtt_websocket.cpp

@@ -0,0 +1,73 @@
+#ifdef QT_WEBSOCKETS_LIB
+
+#include <QNetworkRequest>
+#include <QUrl>
+#include "qmqtt_websocket_p.h"
+
+QMQTT::WebSocket::WebSocket(const QString& origin, QWebSocketProtocol::Version version,
+                            bool ignoreSelfSigned, QObject* parent)
+    : SocketInterface(parent)
+    , _socket(new QWebSocket(origin, version, this))
+    , _ioDevice(new WebSocketIODevice(_socket, this))
+    , _ignoreSelfSigned(ignoreSelfSigned)
+{
+    connect(_socket, &QWebSocket::connected, this, &WebSocket::connected);
+    connect(_socket, &QWebSocket::disconnected, this, &WebSocket::disconnected);
+    connect(_socket,
+            static_cast<void (QWebSocket::*)(QAbstractSocket::SocketError)>(&QWebSocket::error),
+            this,
+            static_cast<void (SocketInterface::*)(QAbstractSocket::SocketError)>(&SocketInterface::error));
+    connect(_socket, &QWebSocket::sslErrors, this, &WebSocket::sslErrors);
+}
+
+QMQTT::WebSocket::~WebSocket()
+{
+}
+
+void QMQTT::WebSocket::connectToHost(const QHostAddress& address, quint16 port)
+{
+    Q_UNUSED(address)
+    Q_UNUSED(port)
+    qFatal("No supported");
+}
+
+void QMQTT::WebSocket::connectToHost(const QString& hostName, quint16 port)
+{
+    Q_UNUSED(port)
+    QUrl url(hostName);
+    QNetworkRequest request(url);
+    request.setRawHeader("Sec-WebSocket-Protocol", "mqtt");
+    _ioDevice->connectToHost(request);
+}
+
+void QMQTT::WebSocket::disconnectFromHost()
+{
+    _socket->disconnect();
+}
+
+QAbstractSocket::SocketState QMQTT::WebSocket::state() const
+{
+    return  _socket->state();
+}
+
+QAbstractSocket::SocketError QMQTT::WebSocket::error() const
+{
+    return _socket->error();
+}
+
+void QMQTT::WebSocket::sslErrors(const QList<QSslError> &errors)
+{
+    if (!_ignoreSelfSigned)
+        return;
+    foreach (QSslError error, errors)
+    {
+        if (error.error() != QSslError::SelfSignedCertificate &&
+            error.error() != QSslError::SelfSignedCertificateInChain)
+        {
+            return;
+        }
+    }
+    _socket->ignoreSslErrors();
+}
+
+#endif // QT_WEBSOCKETS_LIB