NetworkListManager based backend for QNetworkInformation

For Windows. Based on the code I wrote for QNetworkStatusMonitor.
It also renames the netlistmgr feature, avoiding the abbreviation.
Locally my MinGW fails the networklistmanager feature test so it may
not be supported on MinGW, likely leaving it without a backend at all.

Change-Id: I13bbe4127edc2a9c0bb91602c95f1cb206a85a69
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

3 files changed, 381 insertions, 0 deletions

diff --git a/src/plugins/networkinformationbackends/CMakeLists.txt b/src/plugins/networkinformationbackends/CMakeLists.txt
new file mode 100644
index 0000000000..94a1f6baba
--- /dev/null
+++ b/src/plugins/networkinformationbackends/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(WIN32 AND QT_FEATURE_networklistmanager)
+    add_subdirectory(networklistmanager)
+endif()
diff --git a/src/plugins/networkinformationbackends/networklistmanager/CMakeLists.txt b/src/plugins/networkinformationbackends/networklistmanager/CMakeLists.txt
new file mode 100644
index 0000000000..e3dcbfee97
--- /dev/null
+++ b/src/plugins/networkinformationbackends/networklistmanager/CMakeLists.txt
@@ -0,0 +1,8 @@
+qt_internal_add_plugin(QNetworkListManagerNetworkInformationBackend
+    OUTPUT_NAME networklistmanagernetworkinformationbackend
+    TYPE networkinformationbackends
+    DEFAULT_IF WINDOWS AND QT_FEATURE_networklistmanager
+    SOURCES qnetworklistmanagernetworkinformationbackend.cpp
+    PUBLIC_LIBRARIES
+        Qt::NetworkPrivate
+)
diff --git a/src/plugins/networkinformationbackends/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp b/src/plugins/networkinformationbackends/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp
new file mode 100644
index 0000000000..207c82efd9
--- /dev/null
+++ b/src/plugins/networkinformationbackends/networklistmanager/qnetworklistmanagernetworkinformationbackend.cpp
@@ -0,0 +1,370 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtNetwork module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtNetwork/private/qnetworkinformation_p.h>
+
+#include <QtCore/qglobal.h>
+#include <QtCore/private/qobject_p.h>
+
+#include <objbase.h>
+#include <netlistmgr.h>
+#include <wrl/client.h>
+#include <wrl/wrappers/corewrappers.h>
+#include <comdef.h>
+#include <iphlpapi.h>
+using namespace Microsoft::WRL;
+
+QT_BEGIN_NAMESPACE
+Q_DECLARE_LOGGING_CATEGORY(lcNetInfoNLM)
+Q_LOGGING_CATEGORY(lcNetInfoNLM, "qt.network.info.netlistmanager");
+
+static const QString backendName = QStringLiteral("networklistmanager");
+
+namespace {
+QString errorStringFromHResult(HRESULT hr)
+{
+    _com_error error(hr);
+    return QString::fromWCharArray(error.ErrorMessage());
+}
+
+template<typename T>
+bool QueryInterfaceImpl(IUnknown *from, REFIID riid, void **ppvObject)
+{
+    if (riid == __uuidof(T)) {
+        *ppvObject = static_cast<T *>(from);
+        from->AddRef();
+        return true;
+    }
+    return false;
+}
+
+bool testCONNECTIVITY(NLM_CONNECTIVITY connectivity, NLM_CONNECTIVITY flag)
+{
+    return (connectivity & flag) == flag;
+}
+
+QNetworkInformation::Reachability reachabilityFromNLM_CONNECTIVITY(NLM_CONNECTIVITY connectivity)
+{
+    if (connectivity == NLM_CONNECTIVITY_DISCONNECTED)
+        return QNetworkInformation::Reachability::Disconnected;
+    if (testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV6_INTERNET)
+        || testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV4_INTERNET)) {
+        return QNetworkInformation::Reachability::Online;
+    }
+    if (testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV6_SUBNET)
+        || testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV4_SUBNET)) {
+        return QNetworkInformation::Reachability::Site;
+    }
+    if (testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV6_LOCALNETWORK)
+        || testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV4_LOCALNETWORK)) {
+        return QNetworkInformation::Reachability::Local;
+    }
+    if (testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV6_NOTRAFFIC)
+        || testCONNECTIVITY(connectivity, NLM_CONNECTIVITY_IPV4_NOTRAFFIC)) {
+        return QNetworkInformation::Reachability::Unknown;
+    }
+
+    return QNetworkInformation::Reachability::Unknown;
+}
+}
+
+class QNetworkListManagerEvents;
+class QNetworkListManagerNetworkInformationBackend : public QNetworkInformationBackend
+{
+    Q_OBJECT
+public:
+    QNetworkListManagerNetworkInformationBackend();
+    ~QNetworkListManagerNetworkInformationBackend();
+
+    QString name() const override { return backendName; }
+    QNetworkInformation::Features featuresSupported() const override
+    {
+        return featuresSupportedStatic();
+    }
+
+    static QNetworkInformation::Features featuresSupportedStatic()
+    {
+        return QNetworkInformation::Features(QNetworkInformation::Feature::Reachability);
+    }
+
+    [[nodiscard]] bool start();
+    void stop();
+
+private:
+    friend class QNetworkListManagerEvents;
+
+    bool event(QEvent *event) override;
+    void setConnectivity(NLM_CONNECTIVITY newConnectivity);
+
+    ComPtr<QNetworkListManagerEvents> managerEvents;
+
+    NLM_CONNECTIVITY connectivity = NLM_CONNECTIVITY_DISCONNECTED;
+
+    bool monitoring = false;
+    bool comInitFailed = false;
+};
+
+class QNetworkListManagerNetworkInformationBackendFactory : public QNetworkInformationBackendFactory
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID QNetworkInformationBackendFactory_iid)
+    Q_INTERFACES(QNetworkInformationBackendFactory)
+public:
+    QNetworkListManagerNetworkInformationBackendFactory() = default;
+    ~QNetworkListManagerNetworkInformationBackendFactory() = default;
+    QString name() const override { return backendName; }
+    QNetworkInformation::Features featuresSupported() const override
+    {
+        return QNetworkListManagerNetworkInformationBackend::featuresSupportedStatic();
+    }
+
+    QNetworkInformationBackend *
+    create(QNetworkInformation::Features requiredFeatures) const override
+    {
+        if ((requiredFeatures & featuresSupported()) != requiredFeatures)
+            return nullptr;
+        auto backend = new QNetworkListManagerNetworkInformationBackend();
+        if (!backend->start()) {
+            qCWarning(lcNetInfoNLM) << "Failed to start listening to events";
+            delete backend;
+            backend = nullptr;
+        }
+        return backend;
+    }
+};
+
+class QNetworkListManagerEvents : public QObject, public INetworkListManagerEvents
+{
+    Q_OBJECT
+public:
+    QNetworkListManagerEvents();
+    virtual ~QNetworkListManagerEvents();
+
+    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void **ppvObject) override;
+
+    ULONG STDMETHODCALLTYPE AddRef() override { return ++ref; }
+    ULONG STDMETHODCALLTYPE Release() override
+    {
+        if (--ref == 0) {
+            delete this;
+            return 0;
+        }
+        return ref;
+    }
+
+    HRESULT STDMETHODCALLTYPE ConnectivityChanged(NLM_CONNECTIVITY newConnectivity) override;
+
+    [[nodiscard]] bool start();
+    bool stop();
+
+signals:
+    void connectivityChanged(NLM_CONNECTIVITY);
+
+private:
+    ComPtr<INetworkListManager> networkListManager = nullptr;
+    ComPtr<IConnectionPoint> connectionPoint = nullptr;
+
+    QAtomicInteger<ULONG> ref = 0;
+    DWORD cookie = 0;
+};
+
+QNetworkListManagerEvents::QNetworkListManagerEvents() : QObject(nullptr)
+{
+    auto hr = CoCreateInstance(CLSID_NetworkListManager, nullptr, CLSCTX_INPROC_SERVER,
+                               IID_INetworkListManager, &networkListManager);
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Could not get a NetworkListManager instance:"
+                                << errorStringFromHResult(hr);
+        return;
+    }
+
+    ComPtr<IConnectionPointContainer> connectionPointContainer;
+    hr = networkListManager.As(&connectionPointContainer);
+    if (SUCCEEDED(hr)) {
+        hr = connectionPointContainer->FindConnectionPoint(IID_INetworkListManagerEvents,
+                                                           &connectionPoint);
+    }
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Failed to get connection point for network list manager events:"
+                                << errorStringFromHResult(hr);
+    }
+}
+
+QNetworkListManagerEvents::~QNetworkListManagerEvents()
+{
+    Q_ASSERT(ref == 0);
+}
+
+HRESULT STDMETHODCALLTYPE QNetworkListManagerEvents::QueryInterface(REFIID riid, void **ppvObject)
+{
+    if (!ppvObject)
+        return E_INVALIDARG;
+
+    return QueryInterfaceImpl<IUnknown>(this, riid, ppvObject)
+                    || QueryInterfaceImpl<INetworkListManagerEvents>(this, riid, ppvObject)
+            ? S_OK
+            : E_NOINTERFACE;
+}
+
+HRESULT STDMETHODCALLTYPE
+QNetworkListManagerEvents::ConnectivityChanged(NLM_CONNECTIVITY newConnectivity)
+{
+    // This function is run on a different thread than 'monitor' is created on, so we need to run
+    // it on that thread
+    connectivityChanged(newConnectivity);
+    return S_OK;
+}
+
+bool QNetworkListManagerEvents::start()
+{
+    if (!connectionPoint) {
+        qCWarning(lcNetInfoNLM, "Initialization failed, can't start!");
+        return false;
+    }
+    auto hr = connectionPoint->Advise(this, &cookie);
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Failed to subscribe to network connectivity events:"
+                                << errorStringFromHResult(hr);
+        return false;
+    }
+
+    // Update connectivity since it might have changed since this class was constructed
+    NLM_CONNECTIVITY connectivity;
+    hr = networkListManager->GetConnectivity(&connectivity);
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Could not get connectivity:" << errorStringFromHResult(hr);
+    } else {
+        emit connectivityChanged(connectivity);
+    }
+    return true;
+}
+
+bool QNetworkListManagerEvents::stop()
+{
+    Q_ASSERT(connectionPoint);
+    auto hr = connectionPoint->Unadvise(cookie);
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Failed to unsubscribe from network connectivity events:"
+                                << errorStringFromHResult(hr);
+        return false;
+    }
+    cookie = 0;
+    return true;
+}
+
+QNetworkListManagerNetworkInformationBackend::QNetworkListManagerNetworkInformationBackend()
+{
+    auto hr = CoInitialize(nullptr);
+    if (FAILED(hr)) {
+        qCWarning(lcNetInfoNLM) << "Failed to initialize COM:" << errorStringFromHResult(hr);
+        comInitFailed = true;
+        return;
+    }
+    managerEvents = new QNetworkListManagerEvents();
+    connect(managerEvents.Get(), &QNetworkListManagerEvents::connectivityChanged, this,
+            &QNetworkListManagerNetworkInformationBackend::setConnectivity);
+}
+
+QNetworkListManagerNetworkInformationBackend::~QNetworkListManagerNetworkInformationBackend()
+{
+    if (comInitFailed)
+        return;
+    if (monitoring)
+        stop();
+    else
+        CoUninitialize();
+}
+
+void QNetworkListManagerNetworkInformationBackend::setConnectivity(NLM_CONNECTIVITY newConnectivity)
+{
+    if (reachabilityFromNLM_CONNECTIVITY(connectivity)
+        != reachabilityFromNLM_CONNECTIVITY(newConnectivity)) {
+        connectivity = newConnectivity;
+        setReachability(reachabilityFromNLM_CONNECTIVITY(newConnectivity));
+    }
+}
+
+bool QNetworkListManagerNetworkInformationBackend::event(QEvent *event)
+{
+    if (event->type() == QEvent::ThreadChange && monitoring) {
+        stop();
+        QMetaObject::invokeMethod(this, &QNetworkListManagerNetworkInformationBackend::start,
+                                  Qt::QueuedConnection);
+    }
+
+    return QObject::event(event);
+}
+
+bool QNetworkListManagerNetworkInformationBackend::start()
+{
+    Q_ASSERT(!monitoring);
+
+    if (comInitFailed) {
+        auto hr = CoInitialize(nullptr);
+        if (FAILED(hr)) {
+            qCWarning(lcNetInfoNLM) << "Failed to initialize COM:" << errorStringFromHResult(hr);
+            comInitFailed = true;
+            return false;
+        }
+        comInitFailed = false;
+    }
+    if (!managerEvents)
+        managerEvents = new QNetworkListManagerEvents();
+
+    if (managerEvents->start())
+        monitoring = true;
+    return monitoring;
+}
+
+void QNetworkListManagerNetworkInformationBackend::stop()
+{
+    Q_ASSERT(managerEvents);
+    Q_ASSERT(monitoring);
+    // Can return false but realistically shouldn't since that would break everything:
+    managerEvents->stop();
+    monitoring = false;
+    managerEvents.Reset();
+
+    CoUninitialize();
+    comInitFailed = true; // we check this value in start() to see if we need to re-initialize
+}
+
+QT_END_NAMESPACE
+
+#include "qnetworklistmanagernetworkinformationbackend.moc"