Add preferredSecurityFlags to QBluetoothSocket

This permits the API user to determine the security parameters for the
connect attempt to the remote SPP service.

Task-number: QTBUG-46377
Change-Id: I1ed5ea0f5a32aa08dcedc46a34b0377654e420b2
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>

src/bluetooth/qbluetoothsocket.cpp

@@ -486,6 +486,60 @@ QString QBluetoothSocket::errorString() const
     return d->errorString;
 }
 
+/*!
+    Sets the preferred security parameter for the connection attempt to
+    \a flags. This value is incorporated when calling \l connectToService().
+    Therefore it is required to reconnect to change this parameter for an
+    existing connection.
+
+    On Bluez this property is set to QBluetooth::Authorization by default.
+
+    On OS X, this value is ignored as the platform does not permit access
+    to the security parameter of the socket. By default the platform prefers
+    secure/encrypted connections though and therefore this function always
+    returns \l QBluetooth::Secure.
+
+    Android only supports two levels of security (secure and non-secure). If this flag is set to
+    \l QBluetooth::NoSecurity the socket object will not employ any authentication or encryption.
+    Any other security flag combination will trigger a secure Bluetooth connection.
+    This flag is set to \l QBluetooth::Secure by default.
+
+    \note A secure connection requires a pairing between the two devices. On
+    some platforms, the pairing is automatically initiated during the establishment
+    of the connection. Other platforms require the application to manually trigger
+    the pairing before attempting to connect.
+
+    \sa preferredSecurityFlags()
+
+    \since 5.5
+*/
+void QBluetoothSocket::setPreferredSecurityFlags(QBluetooth::SecurityFlags flags)
+{
+    Q_D(QBluetoothSocket);
+    if (d->secFlags != flags)
+        d->secFlags = flags;
+}
+
+/*!
+    Returns the security parameters used for the initial connection
+    attempt.
+
+    The security parameters may be renegotiated between the two parties
+    during or after the connection has been established. If such a change happens
+    it is not reflected in the value of this flag.
+
+    On OS X, this flag is always set to \l QBluetooth::Secure.
+
+    \sa setPreferredSecurityFlags()
+
+    \since 5.5
+*/
+QBluetooth::SecurityFlags QBluetoothSocket::preferredSecurityFlags() const
+{
+    Q_D(const QBluetoothSocket);
+    return d->secFlags;
+}
+
 /*!
     Sets the socket state to \a state.
 */

src/bluetooth/qbluetoothsocket.h

@@ -36,12 +36,13 @@
 
 #include <QtBluetooth/qbluetoothglobal.h>
 
-#include <QtBluetooth/QBluetoothAddress>
-#include <QtBluetooth/QBluetoothUuid>
-#include <QtBluetooth/QBluetoothServiceInfo>
+#include <QtBluetooth/qbluetooth.h>
+#include <QtBluetooth/qbluetoothaddress.h>
+#include <QtBluetooth/qbluetoothuuid.h>
+#include <QtBluetooth/qbluetoothserviceinfo.h>
 
-#include <QtCore/QIODevice>
-#include <QtNetwork/QAbstractSocket>
+#include <QtCore/qiodevice.h>
+#include <QtNetwork/qabstractsocket.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -129,6 +130,9 @@ public:
     //bool waitForDisconnected(int msecs = 30000);
     //virtual bool waitForReadyRead(int msecs = 30000);
 
+    void setPreferredSecurityFlags(QBluetooth::SecurityFlags flags);
+    QBluetooth::SecurityFlags preferredSecurityFlags() const;
+
 Q_SIGNALS:
     void connected();
     void disconnected();

src/bluetooth/qbluetoothsocket_android.cpp

@@ -173,6 +173,7 @@ QBluetoothSocketPrivate::QBluetoothSocketPrivate()
     socketError(QBluetoothSocket::NoSocketError),
     connecting(false),
     discoveryAgent(0),
+    secFlags(QBluetooth::Secure),
     inputThread(0)
 {
     adapter = QAndroidJniObject::callStaticObjectMethod("android/bluetooth/BluetoothAdapter",

src/bluetooth/qbluetoothsocket_bluez.cpp

@@ -64,6 +64,7 @@ QBluetoothSocketPrivate::QBluetoothSocketPrivate()
       connectWriteNotifier(0),
       connecting(false),
       discoveryAgent(0),
+      secFlags(QBluetooth::Authorization),
       lowEnergySocketType(0)
 {
 }

src/bluetooth/qbluetoothsocket_osx.mm

@@ -712,6 +712,18 @@ int QBluetoothSocket::socketDescriptor() const
     return -1;
 }
 
+/* not supported on OS X */
+void QBluetoothSocket::setPreferredSecurityFlags(QBluetooth::SecurityFlags flags)
+{
+    Q_UNUSED(flags)
+}
+
+/* not supported on OS X - platform always uses encryption */
+QBluetooth::SecurityFlags QBluetoothSocket::preferredSecurityFlags() const
+{
+    return QBluetooth::Secure;
+}
+
 #ifndef QT_NO_DEBUG_STREAM
 
 QDebug operator<<(QDebug debug, QBluetoothSocket::SocketError error)

src/bluetooth/qbluetoothsocket_p.cpp

@@ -40,7 +40,8 @@ QBluetoothSocketPrivate::QBluetoothSocketPrivate()
     : socket(-1),
       socketType(QBluetoothServiceInfo::UnknownProtocol),
       state(QBluetoothSocket::UnconnectedState),
-      socketError(QBluetoothSocket::NoSocketError)
+      socketError(QBluetoothSocket::NoSocketError),
+      secFlags(QBluetooth::NoSecurity)
 {
 }
 

src/bluetooth/qbluetoothsocket_p.h

@@ -148,6 +148,7 @@ public:
 
     QBluetoothServiceDiscoveryAgent *discoveryAgent;
     QBluetoothSocket::OpenMode openMode;
+    QBluetooth::SecurityFlags secFlags;
 
 
 //    QByteArray rxBuffer;