Helper class to check whether a network connection can be established

ref #101

src/blackmisc/networkchecks.cpp

@@ -0,0 +1,85 @@
+/* Copyright (C) 2013 VATSIM Community / authors
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "networkchecks.h"
+#include <QtNetwork/QNetworkInterface>
+#include <QtNetwork/QTcpSocket>
+#include <QCoreApplication>
+
+namespace BlackMisc
+{
+    /*
+     * Connected interface?
+     */
+    bool CNetworkChecks::hasConnectedInterface(bool withDebugOutput)
+    {
+        // http://stackoverflow.com/questions/2475266/verfiying-the-network-connection-using-qt-4-4
+        QList<QNetworkInterface> interfaces = QNetworkInterface::allInterfaces();
+        bool result = false;
+
+        for (int i = 0; i < interfaces.count(); i++)
+        {
+            QNetworkInterface iface = interfaces.at(i);
+            if (iface.flags().testFlag(QNetworkInterface::IsUp) && !iface.flags().testFlag(QNetworkInterface::IsLoopBack))
+            {
+
+                // details of connection
+                if (withDebugOutput) qDebug() << "name:" << iface.name() << endl << "ip addresses:" << endl << "mac:" << iface.hardwareAddress() << endl;
+
+                // this loop is important
+                for (int j = 0; j < iface.addressEntries().count(); j++)
+                {
+                    if (withDebugOutput) qDebug() << iface.addressEntries().at(j).ip().toString() << " / " << iface.addressEntries().at(j).netmask().toString() << endl;
+
+                    // we have an interface that is up, and has an ip address, therefore the link is present
+                    // we will only enable this check on first positive, all later results are incorrect
+                    if (!result)
+                    {
+                        result = true;
+                        break;
+                    }
+                }
+            }
+        }
+        return result;
+    }
+
+    /*
+     * Can connect to IP/port?
+     */
+    bool CNetworkChecks::canConnect(const QString &hostAddress, quint16 port, QString &message, int timeoutMs)
+    {
+        if (!CNetworkChecks::hasConnectedInterface(false))
+        {
+            message = QCoreApplication::translate("BlackMisc", "No connected network interface");
+            return false;
+        }
+
+        // http://qt-project.org/forums/viewthread/9346
+        QTcpSocket socket;
+        bool connected = false;
+        socket.connectToHost(hostAddress, port);
+        if (!socket.waitForConnected(timeoutMs))
+        {
+            message = QCoreApplication::translate("BlackMisc", "Connection failed : %1").arg(socket.errorString());
+            connected = false;
+        }
+        else
+        {
+            message = QCoreApplication::translate("BlackMisc", "OK, connected");
+            connected = true;
+        }
+        socket.close();
+        return connected;
+    }
+
+    /*
+     * Can connect server?
+     */
+    bool CNetworkChecks::canConnect(const Network::CServer &server, QString &message, int timeoutMs)
+    {
+        return CNetworkChecks::canConnect(server.getAddress(), server.getPort(), message, timeoutMs);
+    }
+} // namespace

src/blackmisc/networkchecks.h

@@ -0,0 +1,57 @@
+/* Copyright (C) 2013 VATSIM Community / authors
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef BLACKMISC_NETWORKCHECKS_H
+#define BLACKMISC_NETWORKCHECKS_H
+
+#include "nwserver.h"
+#include <QString>
+
+namespace BlackMisc
+{
+
+    /*!
+     * \brief Utilities checking whether a network connection can be established
+     */
+    class CNetworkChecks
+    {
+    private:
+        /*!
+         * \brief Constructor
+         */
+        CNetworkChecks() {}
+
+    public:
+        /*!
+         * \brief Is a connected interface available?
+         * \param withDebugOutput enables some debugging output
+         * \return
+         */
+        static bool hasConnectedInterface(bool withDebugOutput = false);
+
+        /*!
+         * \brief Can connect?
+         * \param hostAddress   130.4.20.3, or myserver.com
+         * \param port          80, 1234
+         * \param timeoutMs
+         * \param message       human readable message
+         * \return
+         */
+        static bool canConnect(const QString &hostAddress, quint16 port, QString &message, int timeoutMs = 1500);
+
+        /*!
+         * \brief Can connect to server?
+         * \param server
+         * \param message       human readable message
+         * \param timeoutMs
+         * \return
+         */
+        static bool canConnect(const BlackMisc::Network::CServer &server, QString &message, int timeoutMs = 1500);
+
+    };
+} // namespace
+
+#endif // guard
+