IPv4 + IPv6 dual stack sockets

Adds support for binding "dual stack" sockets (via QUdpSocket or
QTcpServer). A dual stack socket will accept incoming connections on
either IPv4 or IPv6 interfaces.

QHostAddress::Any     - use this to bind a dual stack socket
QHostAddress::AnyIPv6 - use this to bind a socket for IPv6 only
QHostAddress::AnyIPv4 - use this to bind a socket for IPv4 only

Binding to a specific address rather than one of the "any" addresses
is restricting you to a protocol anyway so no behaviour change there.
IPv6 sockets were previously dual stack on some OS and v6 only on others
Any previously meant IPv4 only

This commit implemented & tested on Windows 7, Linux (Ubuntu 10.04)
and Mac OS 10.6.7.

Windows XP and server 2003 do not support dual stack sockets, even though
they can support IPv6. On those versions, QHostAddress::Any will still
bind to IPv4 0.0.0.0 (which is also the behaviour anywhere QT_NO_IPV6 is
defined)

Autotests run:
qudpsocket (includes a new test case)
qtcpserver (includes a new test case)
qtcpsocket
qnetworkreply
qhostaddress

Task-number: QTBUG-17080
Change-Id: Id486677c4f832e18dc0ff1a86c5f5fc422c9eb4f
Reviewed-on: http://codereview.qt.nokia.com/421
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Thiago Macieira <thiago.macieira@nokia.com>
Reviewed-by: Markus Goetz

4 files changed, 145 insertions, 38 deletions

diff --git a/tests/auto/qhostaddress/tst_qhostaddress.cpp b/tests/auto/qhostaddress/tst_qhostaddress.cpp
index 08eb63cff8..b20e07be03 100644
--- a/tests/auto/qhostaddress/tst_qhostaddress.cpp
+++ b/tests/auto/qhostaddress/tst_qhostaddress.cpp
@@ -269,7 +269,10 @@ void tst_QHostAddress::specialAddresses_data()
     QTest::newRow("broadcast_2") << QString("255.255.255.255") << (int)QHostAddress::Broadcast << true;
 
     QTest::newRow("any_ipv6") << QString("::") << (int)QHostAddress::AnyIPv6 << true;
-    QTest::newRow("any_ipv4") << QString("0.0.0.0") << (int)QHostAddress::Any << true;
+    QTest::newRow("any_ipv4") << QString("0.0.0.0") << (int)QHostAddress::AnyIPv4 << true;
+
+    QTest::newRow("dual_not_ipv6") << QString("::") << (int)QHostAddress::Any << false;
+    QTest::newRow("dual_not_ipv4") << QString("0.0.0.0") << (int)QHostAddress::Any << false;
 }
 
 
@@ -366,8 +369,9 @@ void tst_QHostAddress::streaming_data()
     QTest::newRow("8") << QHostAddress(QHostAddress::LocalHostIPv6);
     QTest::newRow("9") << QHostAddress(QHostAddress::Broadcast);
     QTest::newRow("10") << QHostAddress(QHostAddress::Any);
-    QTest::newRow("11") << QHostAddress(QHostAddress::AnyIPv6);
-    QTest::newRow("12") << QHostAddress("foo.bar.com");
+    QTest::newRow("11") << QHostAddress(QHostAddress::AnyIPv4);
+    QTest::newRow("12") << QHostAddress(QHostAddress::AnyIPv6);
+    QTest::newRow("13") << QHostAddress("foo.bar.com");
 }
 
 void tst_QHostAddress::streaming()
@@ -409,26 +413,26 @@ void tst_QHostAddress::parseSubnet_data()
     QTest::newRow("invalid_23") << "ffff::/ff00::" << QHostAddress() << -1;
 
     // correct IPv4 with netmask
-    QTest::newRow("netmask_0") << "0.0.0.0/0.0.0.0" << QHostAddress(QHostAddress::Any) << 0;
-    QTest::newRow("netmask_1") << "0.0.0.0/255.128.0.0" << QHostAddress(QHostAddress::Any) << 9;
-    QTest::newRow("netmask_2") << "0.0.0.0/255.192.0.0" << QHostAddress(QHostAddress::Any) << 10;
-    QTest::newRow("netmask_3") << "0.0.0.0/255.224.0.0" << QHostAddress(QHostAddress::Any) << 11;
-    QTest::newRow("netmask_4") << "0.0.0.0/255.240.0.0" << QHostAddress(QHostAddress::Any) << 12;
-    QTest::newRow("netmask_5") << "0.0.0.0/255.248.0.0" << QHostAddress(QHostAddress::Any) << 13;
-    QTest::newRow("netmask_6") << "0.0.0.0/255.252.0.0" << QHostAddress(QHostAddress::Any) << 14;
-    QTest::newRow("netmask_7") << "0.0.0.0/255.254.0.0" << QHostAddress(QHostAddress::Any) << 15;
-    QTest::newRow("netmask_8") << "0.0.0.0/255.255.0.0" << QHostAddress(QHostAddress::Any) << 16;
-    QTest::newRow("netmask_16") << "0.0.0.0/255.255.0.0" << QHostAddress(QHostAddress::Any) << 16;
-    QTest::newRow("netmask_24") << "0.0.0.0/255.255.255.0" << QHostAddress(QHostAddress::Any) << 24;
-    QTest::newRow("netmask_31") << "0.0.0.0/255.255.255.254" << QHostAddress(QHostAddress::Any) << 31;
-    QTest::newRow("netmask_32") << "0.0.0.0/255.255.255.255" << QHostAddress(QHostAddress::Any) << 32;
+    QTest::newRow("netmask_0") << "0.0.0.0/0.0.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 0;
+    QTest::newRow("netmask_1") << "0.0.0.0/255.128.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 9;
+    QTest::newRow("netmask_2") << "0.0.0.0/255.192.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 10;
+    QTest::newRow("netmask_3") << "0.0.0.0/255.224.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 11;
+    QTest::newRow("netmask_4") << "0.0.0.0/255.240.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 12;
+    QTest::newRow("netmask_5") << "0.0.0.0/255.248.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 13;
+    QTest::newRow("netmask_6") << "0.0.0.0/255.252.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 14;
+    QTest::newRow("netmask_7") << "0.0.0.0/255.254.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 15;
+    QTest::newRow("netmask_8") << "0.0.0.0/255.255.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 16;
+    QTest::newRow("netmask_16") << "0.0.0.0/255.255.0.0" << QHostAddress(QHostAddress::AnyIPv4) << 16;
+    QTest::newRow("netmask_24") << "0.0.0.0/255.255.255.0" << QHostAddress(QHostAddress::AnyIPv4) << 24;
+    QTest::newRow("netmask_31") << "0.0.0.0/255.255.255.254" << QHostAddress(QHostAddress::AnyIPv4) << 31;
+    QTest::newRow("netmask_32") << "0.0.0.0/255.255.255.255" << QHostAddress(QHostAddress::AnyIPv4) << 32;
 
     // correct IPv4 with prefix
-    QTest::newRow("prefix_0") << "0.0.0.0/0" << QHostAddress(QHostAddress::Any) << 0;
-    QTest::newRow("prefix_1") << "0.0.0.0/1" << QHostAddress(QHostAddress::Any) << 1;
-    QTest::newRow("prefix_9") << "0.0.0.0/9" << QHostAddress(QHostAddress::Any) << 9;
-    QTest::newRow("prefix_31") << "0.0.0.0/31" << QHostAddress(QHostAddress::Any) << 31;
-    QTest::newRow("prefix_32") << "0.0.0.0/32" << QHostAddress(QHostAddress::Any) << 32;
+    QTest::newRow("prefix_0") << "0.0.0.0/0" << QHostAddress(QHostAddress::AnyIPv4) << 0;
+    QTest::newRow("prefix_1") << "0.0.0.0/1" << QHostAddress(QHostAddress::AnyIPv4) << 1;
+    QTest::newRow("prefix_9") << "0.0.0.0/9" << QHostAddress(QHostAddress::AnyIPv4) << 9;
+    QTest::newRow("prefix_31") << "0.0.0.0/31" << QHostAddress(QHostAddress::AnyIPv4) << 31;
+    QTest::newRow("prefix_32") << "0.0.0.0/32" << QHostAddress(QHostAddress::AnyIPv4) << 32;
 
     // correct IPv4 without prefix or netmask
     QTest::newRow("classA") << "10" << QHostAddress("10.0.0.0") << 8;
@@ -533,22 +537,22 @@ void tst_QHostAddress::isInSubnet_data()
 
     // invalid QHostAddresses are never in any subnets
     QTest::newRow("invalid_01") << QHostAddress() << QHostAddress() << 32 << false;
-    QTest::newRow("invalid_02") << QHostAddress() << QHostAddress(QHostAddress::Any) << 32 << false;
-    QTest::newRow("invalid_03") << QHostAddress() << QHostAddress(QHostAddress::Any) << 8 << false;
-    QTest::newRow("invalid_04") << QHostAddress() << QHostAddress(QHostAddress::Any) << 0 << false;
+    QTest::newRow("invalid_02") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv4) << 32 << false;
+    QTest::newRow("invalid_03") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv4) << 8 << false;
+    QTest::newRow("invalid_04") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv4) << 0 << false;
     QTest::newRow("invalid_05") << QHostAddress() << QHostAddress("255.255.255.0") << 24 << false;
     QTest::newRow("invalid_06") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv6) << 0 << false;
     QTest::newRow("invalid_07") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv6) << 32 << false;
     QTest::newRow("invalid_08") << QHostAddress() << QHostAddress(QHostAddress::AnyIPv6) << 128<< false;
 
     // and no host address can be in a subnet whose prefix is invalid
-    QTest::newRow("invalid_20") << QHostAddress(QHostAddress::Any) << QHostAddress() << 16 << false;
+    QTest::newRow("invalid_20") << QHostAddress(QHostAddress::AnyIPv4) << QHostAddress() << 16 << false;
     QTest::newRow("invalid_21") << QHostAddress(QHostAddress::AnyIPv6) << QHostAddress() << 16 << false;
     QTest::newRow("invalid_22") << QHostAddress(QHostAddress::LocalHost) << QHostAddress() << 16 << false;
     QTest::newRow("invalid_23") << QHostAddress(QHostAddress::LocalHostIPv6) << QHostAddress() << 16 << false;
 
     // negative netmasks don't make sense:
-    QTest::newRow("invalid_30") << QHostAddress(QHostAddress::Any) << QHostAddress(QHostAddress::Any) << -1 << false;
+    QTest::newRow("invalid_30") << QHostAddress(QHostAddress::AnyIPv4) << QHostAddress(QHostAddress::Any) << -1 << false;
     QTest::newRow("invalid_31") << QHostAddress(QHostAddress::AnyIPv6) << QHostAddress(QHostAddress::AnyIPv6) << -1 << false;
 
     // we don't support IPv4 belonging in an IPv6 netmask and vice-versa
@@ -558,10 +562,10 @@ void tst_QHostAddress::isInSubnet_data()
     QTest::newRow("v4-in-v6mapped2") << QHostAddress(QHostAddress::LocalHost) << QHostAddress("::ffff:255.0.0.0") << 113 << false;
 
     // IPv4 correct ones
-    QTest::newRow("netmask_0") << QHostAddress(QHostAddress::LocalHost) << QHostAddress(QHostAddress::Any) << 0 << true;
+    QTest::newRow("netmask_0") << QHostAddress(QHostAddress::LocalHost) << QHostAddress(QHostAddress::AnyIPv4) << 0 << true;
     QTest::newRow("netmask_0bis") << QHostAddress(QHostAddress::LocalHost) << QHostAddress("255.255.0.0") << 0 << true;
     QTest::newRow("netmask_0ter") << QHostAddress(QHostAddress::LocalHost) << QHostAddress("1.2.3.4") << 0 << true;
-    QTest::newRow("netmask_1") << QHostAddress(QHostAddress::LocalHost) << QHostAddress(QHostAddress::Any) << 1 << true;
+    QTest::newRow("netmask_1") << QHostAddress(QHostAddress::LocalHost) << QHostAddress(QHostAddress::AnyIPv4) << 1 << true;
     QTest::newRow("~netmask_1") << QHostAddress(QHostAddress::LocalHost) << QHostAddress("128.0.0.0") << 1 << false;
     QTest::newRow("netmask_1bis") << QHostAddress("224.0.0.1") << QHostAddress("128.0.0.0") << 1 << true;
     QTest::newRow("~netmask_1bis") << QHostAddress("224.0.0.1") << QHostAddress("0.0.0.0") << 1 << false;
diff --git a/tests/auto/qtcpserver/tst_qtcpserver.cpp b/tests/auto/qtcpserver/tst_qtcpserver.cpp
index 3416a7cb23..beeb6c7655 100644
--- a/tests/auto/qtcpserver/tst_qtcpserver.cpp
+++ b/tests/auto/qtcpserver/tst_qtcpserver.cpp
@@ -97,6 +97,8 @@ private slots:
     void constructing();
     void clientServerLoop();
     void ipv6Server();
+    void dualStack_data();
+    void dualStack();
     void ipv6ServerMapped();
     void crashTests();
     void maxPendingConnections();
@@ -265,6 +267,44 @@ void tst_QTcpServer::ipv6Server()
     delete serverSocket;
 }
 
+Q_DECLARE_METATYPE(QHostAddress);
+
+void tst_QTcpServer::dualStack_data()
+{
+    QTest::addColumn<QHostAddress>("bindAddress");
+    QTest::addColumn<bool>("v4ok");
+    QTest::addColumn<bool>("v6ok");
+    QTest::newRow("any") << QHostAddress(QHostAddress::Any) << true << true;
+    QTest::newRow("anyIPv4") << QHostAddress(QHostAddress::AnyIPv4) << true << false;
+    QTest::newRow("anyIPv6") << QHostAddress(QHostAddress::AnyIPv6) << false << true;
+}
+
+void tst_QTcpServer::dualStack()
+{
+#ifdef QT_NO_IPV6
+    QSKIP("test requires IPv6 support", SkipAll);
+#else
+    QFETCH_GLOBAL(bool, setProxy);
+    if (setProxy)
+        QSKIP("test server proxy doesn't support ipv6", SkipSingle);
+    QFETCH(QHostAddress, bindAddress);
+    QFETCH(bool, v4ok);
+    QFETCH(bool, v6ok);
+
+    QTcpServer server;
+    QVERIFY(server.listen(bindAddress));
+
+    QTcpSocket v4client;
+    v4client.connectToHost(QHostAddress::LocalHost, server.serverPort());
+
+    QTcpSocket v6client;
+    v6client.connectToHost(QHostAddress::LocalHostIPv6, server.serverPort());
+
+    QCOMPARE(v4client.waitForConnected(5000), v4ok);
+    QCOMPARE(v6client.waitForConnected(5000), v6ok);
+#endif
+}
+
 //----------------------------------------------------------------------------------
 void tst_QTcpServer::ipv6ServerMapped()
 {
diff --git a/tests/auto/qtcpsocket/tst_qtcpsocket.cpp b/tests/auto/qtcpsocket/tst_qtcpsocket.cpp
index a2f8bac517..39a64ab0dc 100644
--- a/tests/auto/qtcpsocket/tst_qtcpsocket.cpp
+++ b/tests/auto/qtcpsocket/tst_qtcpsocket.cpp
@@ -1506,7 +1506,7 @@ void tst_QTcpSocket::dontCloseOnTimeout()
     QVERIFY(server.listen());
 
     QHostAddress serverAddress = QHostAddress::LocalHost;
-    if (!(server.serverAddress() == QHostAddress::Any) && !(server.serverAddress() == QHostAddress::AnyIPv6))
+    if (!(server.serverAddress() == QHostAddress::AnyIPv4) && !(server.serverAddress() == QHostAddress::AnyIPv6))
         serverAddress = server.serverAddress();
 
     QTcpSocket *socket = newSocket();
diff --git a/tests/auto/qudpsocket/tst_qudpsocket.cpp b/tests/auto/qudpsocket/tst_qudpsocket.cpp
index 9ca049bccf..03e224682f 100644
--- a/tests/auto/qudpsocket/tst_qudpsocket.cpp
+++ b/tests/auto/qudpsocket/tst_qudpsocket.cpp
@@ -90,6 +90,7 @@ private slots:
     void loop();
     void ipv6Loop_data();
     void ipv6Loop();
+    void dualStack();
     void readLine();
     void pendingDatagramSize();
     void writeDatagram();
@@ -212,7 +213,7 @@ void tst_QUdpSocket::unconnectedServerAndClientTest()
     const char *message[] = {"Yo mista", "Yo", "Wassap"};
 
     QHostAddress serverAddress = QHostAddress::LocalHost;
-    if (!(serverSocket.localAddress() == QHostAddress::Any || serverSocket.localAddress() == QHostAddress::AnyIPv6))
+    if (!(serverSocket.localAddress() == QHostAddress::AnyIPv4 || serverSocket.localAddress() == QHostAddress::AnyIPv6))
         serverAddress = serverSocket.localAddress();
 
     for (int i = 0; i < 3; ++i) {
@@ -343,10 +344,10 @@ void tst_QUdpSocket::loop()
     QVERIFY2(paul.bind(), paul.errorString().toLatin1().constData());
 
     QHostAddress peterAddress = QHostAddress::LocalHost;
-    if (!(peter.localAddress() == QHostAddress::Any || peter.localAddress() == QHostAddress::AnyIPv6))
+    if (!(peter.localAddress() == QHostAddress::AnyIPv4 || peter.localAddress() == QHostAddress::AnyIPv6))
         peterAddress = peter.localAddress();
     QHostAddress pualAddress = QHostAddress::LocalHost;
-    if (!(paul.localAddress() == QHostAddress::Any || paul.localAddress() == QHostAddress::AnyIPv6))
+    if (!(paul.localAddress() == QHostAddress::AnyIPv4 || paul.localAddress() == QHostAddress::AnyIPv6))
         pualAddress = paul.localAddress();
 
     QCOMPARE(peter.writeDatagram(peterMessage.data(), peterMessage.length(),
@@ -428,6 +429,64 @@ void tst_QUdpSocket::ipv6Loop()
     }
 }
 
+void tst_QUdpSocket::dualStack()
+{
+    QFETCH_GLOBAL(bool, setProxy);
+    if (setProxy)
+        QSKIP("test server SOCKS proxy doesn't support IPv6", SkipSingle);
+    QUdpSocket dualSock;
+    QByteArray dualData("dual");
+    QVERIFY(dualSock.bind(QHostAddress(QHostAddress::Any), 0));
+
+    QUdpSocket v4Sock;
+    QByteArray v4Data("v4");
+    QVERIFY(v4Sock.bind(QHostAddress(QHostAddress::AnyIPv4), 0));
+
+    QUdpSocket v6Sock;
+    QByteArray v6Data("v6");
+    QVERIFY(v6Sock.bind(QHostAddress(QHostAddress::AnyIPv6), 0));
+
+    QHostAddress from;
+    quint16 port;
+    QByteArray buffer;
+    //test v4 -> dual
+    QCOMPARE((int)v4Sock.writeDatagram(v4Data.constData(), v4Data.length(), QHostAddress(QHostAddress::LocalHost), dualSock.localPort()), v4Data.length());
+    QVERIFY(dualSock.waitForReadyRead(5000));
+    buffer.reserve(100);
+    qint64 size = dualSock.readDatagram(buffer.data(), 100, &from, &port);
+    QCOMPARE((int)size, v4Data.length());
+    buffer.resize(size);
+    QCOMPARE(buffer, v4Data);
+
+    //test v6 -> dual
+    QCOMPARE((int)v6Sock.writeDatagram(v6Data.constData(), v6Data.length(), QHostAddress(QHostAddress::LocalHostIPv6), dualSock.localPort()), v6Data.length());
+    QVERIFY(dualSock.waitForReadyRead(5000));
+    buffer.reserve(100);
+    size = dualSock.readDatagram(buffer.data(), 100, &from, &port);
+    QCOMPARE((int)size, v6Data.length());
+    buffer.resize(size);
+    QCOMPARE(buffer, v6Data);
+
+    //test dual -> v4
+    QCOMPARE((int)dualSock.writeDatagram(dualData.constData(), dualData.length(), QHostAddress(QHostAddress::LocalHost), v4Sock.localPort()), dualData.length());
+    QVERIFY(v4Sock.waitForReadyRead(5000));
+    buffer.reserve(100);
+    size = v4Sock.readDatagram(buffer.data(), 100, &from, &port);
+    QCOMPARE((int)size, dualData.length());
+    buffer.resize(size);
+    QCOMPARE(buffer, dualData);
+
+    //test dual -> v6
+    QCOMPARE((int)dualSock.writeDatagram(dualData.constData(), dualData.length(), QHostAddress(QHostAddress::LocalHostIPv6), v6Sock.localPort()), dualData.length());
+    QVERIFY(v6Sock.waitForReadyRead(5000));
+    buffer.reserve(100);
+    size = v6Sock.readDatagram(buffer.data(), 100, &from, &port);
+    QCOMPARE((int)size, dualData.length());
+    buffer.resize(size);
+    QCOMPARE(buffer, dualData);
+
+}
+
 void tst_QUdpSocket::empty_readyReadSlot()
 {
     QTestEventLoop::instance().exitLoop();
@@ -465,7 +524,7 @@ void tst_QUdpSocket::pendingDatagramSize()
     QVERIFY2(server.bind(), server.errorString().toLatin1().constData());
 
     QHostAddress serverAddress = QHostAddress::LocalHost;
-    if (!(server.localAddress() == QHostAddress::Any || server.localAddress() == QHostAddress::AnyIPv6))
+    if (!(server.localAddress() == QHostAddress::AnyIPv4 || server.localAddress() == QHostAddress::AnyIPv6))
         serverAddress = server.localAddress();
 
     QUdpSocket client;
@@ -519,7 +578,7 @@ void tst_QUdpSocket::writeDatagram()
     QVERIFY2(server.bind(), server.errorString().toLatin1().constData());
 
     QHostAddress serverAddress = QHostAddress::LocalHost;
-    if (!(server.localAddress() == QHostAddress::Any || server.localAddress() == QHostAddress::AnyIPv6))
+    if (!(server.localAddress() == QHostAddress::AnyIPv4 || server.localAddress() == QHostAddress::AnyIPv6))
         serverAddress = server.localAddress();
 
     QUdpSocket client;
@@ -592,7 +651,7 @@ void tst_QUdpSocket::performance()
     QVERIFY2(server.bind(), server.errorString().toLatin1().constData());
 
     QHostAddress serverAddress = QHostAddress::LocalHost;
-    if (!(server.localAddress() == QHostAddress::Any || server.localAddress() == QHostAddress::AnyIPv6))
+    if (!(server.localAddress() == QHostAddress::AnyIPv4 || server.localAddress() == QHostAddress::AnyIPv6))
         serverAddress = server.localAddress();
 
     QUdpSocket client;
@@ -1147,7 +1206,7 @@ void tst_QUdpSocket::setMulticastInterface()
 
 void tst_QUdpSocket::multicast_data()
 {
-    QHostAddress anyAddress = QHostAddress(QHostAddress::Any);
+    QHostAddress anyAddress = QHostAddress(QHostAddress::AnyIPv4);
     QHostAddress groupAddress = QHostAddress("239.255.118.62");
     QHostAddress any6Address = QHostAddress(QHostAddress::AnyIPv6);
     QHostAddress group6Address = QHostAddress("FF01::114");
@@ -1173,8 +1232,12 @@ void tst_QUdpSocket::multicast()
     QFETCH(bool, joinResult);
     if (setProxy) {
         // UDP multicast does not work with proxies
-        if ((bindAddress.protocol() == QAbstractSocket::IPv4Protocol && (bindAddress.toIPv4Address() & 0xffff0000) == 0xefff0000)
-            || bindAddress.protocol() == QAbstractSocket::IPv6Protocol) {
+        if (
+#ifndef Q_OS_WIN
+            //windows native socket engine binds 0.0.0.0 instead of the requested multicast address
+            (bindAddress.protocol() == QAbstractSocket::IPv4Protocol && (bindAddress.toIPv4Address() & 0xffff0000) == 0xefff0000) ||
+#endif
+            bindAddress.protocol() == QAbstractSocket::IPv6Protocol) {
             // proxy cannot bind to IPv6 or multicast addresses
             bindResult = false;
         }