qbluetoothsocket_winrt: Use recommended service connection approach if possible

MSDN documentation states that the recommended way of RFCOMM service
connection is via connectionHostName and connectionServiceName (see
https://docs.microsoft.com/en-us/uwp/api/windows.devices.bluetooth.rfcomm.rfcommdeviceservice).
So whenever possible, we should use this information from the native
device service when connecting directly to the discovered service.

As QBluetoothServiceInfo is basically just a wrapper for the attributes
map this information is stored in its private pendant and extracted when
a connection attempt is being made.

Task-number: QTBUG-62520
Change-Id: I95be5df89a722531393b45fd136d37f302393ca8
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

src/bluetooth/qbluetoothservicediscoveryagent_winrt.cpp

@@ -52,6 +52,7 @@
 #include <windows.devices.enumeration.h>
 #include <windows.devices.bluetooth.h>
 #include <windows.foundation.collections.h>
+#include <windows.networking.h>
 #include <windows.storage.streams.h>
 #include <wrl.h>
 
@@ -208,6 +209,14 @@ void QWinRTBluetoothServiceDiscoveryWorker::processServiceSearchResult(quint64 a
         hr = service->get_ConnectionServiceName(name.GetAddressOf());
         Q_ASSERT_SUCCEEDED(hr);
         const QString serviceName = QString::fromWCharArray(WindowsGetStringRawBuffer(name.Get(), nullptr));
+        ComPtr<ABI::Windows::Networking::IHostName> host;
+        hr = service->get_ConnectionHostName(host.GetAddressOf());
+        Q_ASSERT_SUCCEEDED(hr);
+        HString hostName;
+        hr = host->get_RawName(hostName.GetAddressOf());
+        Q_ASSERT_SUCCEEDED(hr);
+        const QString qHostName = QString::fromWCharArray(WindowsGetStringRawBuffer(hostName.Get(),
+                                                                                    nullptr));
         ComPtr<IRfcommServiceId> id;
         hr = service->get_ServiceId(&id);
         Q_ASSERT_SUCCEEDED(hr);
@@ -217,6 +226,8 @@ void QWinRTBluetoothServiceDiscoveryWorker::processServiceSearchResult(quint64 a
         Q_ASSERT_SUCCEEDED(hr);
 
         QBluetoothServiceInfo info;
+        info.setAttribute(0xBEEF, QVariant(qHostName));
+        info.setAttribute(0xBEF0, QVariant(serviceName));
         info.setServiceName(serviceName);
         info.setServiceUuid(uuid);
         ComPtr<IAsyncOperation<IMapView<UINT32, IBuffer *> *>> op;

src/bluetooth/qbluetoothsocket.cpp

@@ -640,6 +640,13 @@ void QBluetoothSocket::serviceDiscovered(const QBluetoothServiceInfo &service)
         connectToService(service, d->openMode);
         d->discoveryAgent->deleteLater();
         d->discoveryAgent = nullptr;
+#ifdef QT_WINRT_BLUETOOTH
+    } else if (!service.attribute(0xBEEF).isNull()
+               && !service.attribute(0xBEF0).isNull()) {
+        connectToService(service, d->openMode);
+        d->discoveryAgent->deleteLater();
+        d->discoveryAgent = nullptr;
+#endif
     } else {
         qCDebug(QT_BT) << "Could not find port/psm for potential remote service";
     }

src/bluetooth/qbluetoothsocket_winrt.cpp

@@ -359,10 +359,11 @@ bool QBluetoothSocketPrivateWinRT::ensureNativeSocket(QBluetoothServiceInfo::Pro
     return true;
 }
 
-void QBluetoothSocketPrivateWinRT::connectToServiceHelper(const QBluetoothAddress &address, quint16 port, QIODevice::OpenMode openMode)
+void QBluetoothSocketPrivateWinRT::connectToService(Microsoft::WRL::ComPtr<IHostName> hostName,
+                                                    const QString &serviceName,
+                                                    QIODevice::OpenMode openMode)
 {
     Q_Q(QBluetoothSocket);
-    Q_UNUSED(openMode);
 
     if (socket == -1 && !ensureNativeSocket(socketType)) {
         errorString = QBluetoothSocket::tr("Unknown socket error");
@@ -370,20 +371,9 @@ void QBluetoothSocketPrivateWinRT::connectToServiceHelper(const QBluetoothAddres
         return;
     }
 
-    const QString addressString = address.toString();
+    HStringReference serviceNameReference(reinterpret_cast<LPCWSTR>(serviceName.utf16()));
-    HStringReference hostNameRef(reinterpret_cast<LPCWSTR>(addressString.utf16()));
-    ComPtr<IHostNameFactory> hostNameFactory;
-    HRESULT hr = GetActivationFactory(HString::MakeReference(RuntimeClass_Windows_Networking_HostName).Get(),
-                                      &hostNameFactory);
-    Q_ASSERT_SUCCEEDED(hr);
-    ComPtr<IHostName> remoteHost;
-    hr = hostNameFactory->CreateHostName(hostNameRef.Get(), &remoteHost);
-    RETURN_VOID_IF_FAILED("QBluetoothSocketPrivateWinRT::connectToService: Could not create hostname.");
 
-    const QString portString = QString::number(port);
+    HRESULT hr = m_socketObject->ConnectAsync(hostName.Get(), serviceNameReference.Get(), &m_connectOp);
-    HStringReference portReference(reinterpret_cast<LPCWSTR>(portString.utf16()));
-
-    hr = m_socketObject->ConnectAsync(remoteHost.Get(), portReference.Get(), &m_connectOp);
     if (hr == E_ACCESSDENIED) {
         qErrnoWarning(hr, "QBluetoothSocketPrivateWinRT::connectToService: Unable to connect to bluetooth socket."
             "Please check your manifest capabilities.");
@@ -404,6 +394,29 @@ void QBluetoothSocketPrivateWinRT::connectToServiceHelper(const QBluetoothAddres
     Q_ASSERT_SUCCEEDED(hr);
 }
 
+void QBluetoothSocketPrivateWinRT::connectToServiceHelper(const QBluetoothAddress &address, quint16 port, QIODevice::OpenMode openMode)
+{
+    Q_Q(QBluetoothSocket);
+
+    if (socket == -1 && !ensureNativeSocket(socketType)) {
+        errorString = QBluetoothSocket::tr("Unknown socket error");
+        q->setSocketError(QBluetoothSocket::UnknownSocketError);
+        return;
+    }
+
+    const QString addressString = address.toString();
+    HStringReference hostNameRef(reinterpret_cast<LPCWSTR>(addressString.utf16()));
+    ComPtr<IHostNameFactory> hostNameFactory;
+    HRESULT hr = GetActivationFactory(HString::MakeReference(RuntimeClass_Windows_Networking_HostName).Get(),
+                                      &hostNameFactory);
+    Q_ASSERT_SUCCEEDED(hr);
+    ComPtr<IHostName> remoteHost;
+    hr = hostNameFactory->CreateHostName(hostNameRef.Get(), &remoteHost);
+    RETURN_VOID_IF_FAILED("QBluetoothSocketPrivateWinRT::connectToService: Could not create hostname.");
+    const QString portString = QString::number(port);
+    connectToService(remoteHost, portString, openMode);
+}
+
 void QBluetoothSocketPrivateWinRT::connectToService(
         const QBluetoothServiceInfo &service, QIODevice::OpenMode openMode)
 {
@@ -425,6 +438,8 @@ void QBluetoothSocketPrivateWinRT::connectToService(
         return;
     }
 
+    const QString connectionHostName = service.attribute(0xBEEF).toString();
+    const QString connectionServiceName = service.attribute(0xBEF0).toString();
     if (service.protocolServiceMultiplexer() > 0) {
         Q_ASSERT(service.socketProtocol() == QBluetoothServiceInfo::L2capProtocol);
 
@@ -434,6 +449,21 @@ void QBluetoothSocketPrivateWinRT::connectToService(
            return;
        }
        connectToServiceHelper(service.device().address(), service.protocolServiceMultiplexer(), openMode);
+    } else if (!connectionHostName.isEmpty() && !connectionServiceName.isEmpty()) {
+        Q_ASSERT(service.socketProtocol() == QBluetoothServiceInfo::RfcommProtocol);
+        if (!ensureNativeSocket(QBluetoothServiceInfo::RfcommProtocol)) {
+            errorString = QBluetoothSocket::tr("Unknown socket error");
+            q->setSocketError(QBluetoothSocket::UnknownSocketError);
+            return;
+        }
+        HStringReference hostNameRef(reinterpret_cast<LPCWSTR>(connectionHostName.utf16()));
+        ComPtr<IHostNameFactory> hostNameFactory;
+        HRESULT hr = GetActivationFactory(HString::MakeReference(RuntimeClass_Windows_Networking_HostName).Get(),
+                                          &hostNameFactory);
+        Q_ASSERT_SUCCEEDED(hr);
+        ComPtr<IHostName> remoteHost;
+        hr = hostNameFactory->CreateHostName(hostNameRef.Get(), &remoteHost);
+        connectToService(remoteHost, connectionServiceName, openMode);
     } else if (service.serverChannel() > 0) {
         Q_ASSERT(service.socketProtocol() == QBluetoothServiceInfo::RfcommProtocol);
 

src/bluetooth/qbluetoothsocket_winrt_p.h

@@ -57,6 +57,19 @@
 
 QT_FORWARD_DECLARE_CLASS(SocketWorker)
 
+namespace ABI {
+    namespace Windows {
+        namespace  Networking {
+            struct IHostName;
+        }
+    }
+}
+
+namespace Microsoft {
+    namespace WRL {
+        template <typename T> class ComPtr;
+    }
+}
 QT_BEGIN_NAMESPACE
 
 class QBluetoothSocketPrivateWinRT final: public QBluetoothSocketBasePrivate
@@ -125,6 +138,8 @@ private slots:
     void handleError(QBluetoothSocket::SocketError error);
 
 private:
+    void connectToService(Microsoft::WRL::ComPtr<ABI::Windows::Networking::IHostName> hostName,
+                          const QString &serviceName, QIODevice::OpenMode openMode);
     HRESULT handleConnectOpFinished(ABI::Windows::Foundation::IAsyncAction *action,
                                     ABI::Windows::Foundation::AsyncStatus status);