Add test case for link local TCP connections

The socket engines already implemented this, but it is a good idea
to test it explicitly.

Task-number: QTBUG-25634
Change-Id: Ife3fe09b0119ed435e4055523c553847739a09fe
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(back ported from commit e5f77fe31be0ea2c891eacd3e866bb9db4e0a238)

1 files changed, 72 insertions, 0 deletions

diff --git a/tests/auto/qtcpserver/tst_qtcpserver.cpp b/tests/auto/qtcpserver/tst_qtcpserver.cpp
index 0052518..dd3d43d 100644
--- a/tests/auto/qtcpserver/tst_qtcpserver.cpp
+++ b/tests/auto/qtcpserver/tst_qtcpserver.cpp
@@ -115,6 +115,8 @@ private slots:
 
     void qtbug6305();
 
+    void linkLocal();
+
 private:
 #ifndef QT_NO_BEARERMANAGEMENT
     QNetworkSession *networkSession;
@@ -805,5 +807,75 @@ void tst_QTcpServer::qtbug6305()
     QVERIFY(!server2.listen(QHostAddress::Any, server.serverPort())); // second listen should fail
 }
 
+void tst_QTcpServer::linkLocal()
+{
+    QFETCH_GLOBAL(bool, setProxy);
+    if (setProxy)
+        return;
+
+    QList <QHostAddress> addresses;
+    QSet <QString> scopes;
+    QHostAddress localMaskv4("169.254.0.0");
+    QHostAddress localMaskv6("fe80::");
+    foreach (const QNetworkInterface& iface, QNetworkInterface::allInterfaces()) {
+        //Windows preallocates link local addresses to interfaces that are down.
+        //These may or may not work depending on network driver (they do not work for the Bluetooth PAN driver)
+        if (iface.flags() & QNetworkInterface::IsUp) {
+            foreach (QNetworkAddressEntry addressEntry, iface.addressEntries()) {
+                QHostAddress addr = addressEntry.ip();
+                if (addr.isInSubnet(localMaskv4, 16)) {
+                    addresses << addr;
+                    qDebug() << addr;
+                }
+                else if (!addr.scopeId().isEmpty() && addr.isInSubnet(localMaskv6, 64)) {
+                    scopes << addr.scopeId();
+                    addresses << addr;
+                    qDebug() << addr;
+                }
+            }
+        }
+    }
+    if (addresses.isEmpty())
+        QSKIP("no link local addresses", SkipSingle);
+
+    QList<QTcpServer*> servers;
+    quint16 port = 0;
+    foreach (const QHostAddress& addr, addresses) {
+        QTcpServer *server = new QTcpServer;
+        QVERIFY(server->listen(addr, port));
+        port = server->serverPort(); //listen to same port on different interfaces
+        servers << server;
+    }
+
+    QList<QTcpSocket*> clients;
+    foreach (const QHostAddress& addr, addresses) {
+        //unbound socket (note, bound TCP client socket not supported by Qt 4.8)
+        QTcpSocket *socket = new QTcpSocket;
+        socket->connectToHost(addr, port);
+        QVERIFY(socket->waitForConnected(5000));
+        clients << socket;
+    }
+
+    //each server should have one connection
+    foreach (QTcpServer* server, servers) {
+        QTcpSocket* remote;
+        //qDebug() << "checking for connections" << server->serverAddress() << ":" << server->serverPort();
+        QVERIFY(server->waitForNewConnection(5000));
+        QVERIFY(remote = server->nextPendingConnection());
+        remote->close();
+        delete remote;
+        QVERIFY(!server->hasPendingConnections());
+    }
+
+    //Connecting to the same address with different scope should normally fail
+    //However it will pass if there are two interfaces connected to the same physical network,
+    //e.g. connected via wired and wireless interfaces, or two wired NICs.
+    //which is a reasonably common case.
+    //So this is not auto tested.
+
+    qDeleteAll(clients);
+    qDeleteAll(servers);
+}
+
 QTEST_MAIN(tst_QTcpServer)
 #include "tst_qtcpserver.moc"