QSslSocket: Trigger a SSL transmission when reading from the socket.

In certain cases a SSL transfer stalled when a readBufferSize was set.
This change triggers a SSL transmission when there is data on the
socket waiting to be decrypted.

Task-number: QTBUG-3860
Reviewed-by: Thiago

4 files changed, 78 insertions, 0 deletions

diff --git a/src/network/ssl/qsslsocket.cpp b/src/network/ssl/qsslsocket.cpp
index ad766c1..2c88130 100644
--- a/src/network/ssl/qsslsocket.cpp
+++ b/src/network/ssl/qsslsocket.cpp
@@ -1740,6 +1740,11 @@ qint64 QSslSocket::readData(char *data, qint64 maxlen)
 #ifdef QSSLSOCKET_DEBUG
     qDebug() << "QSslSocket::readData(" << (void *)data << ',' << maxlen << ") ==" << readBytes;
 #endif
+
+    // possibly trigger another transmit() to decrypt more data from the socket
+    if (d->readBuffer.isEmpty() && d->plainSocket->bytesAvailable())
+        QMetaObject::invokeMethod(this, "_q_flushReadBuffer", Qt::QueuedConnection);
+
     return readBytes;
 }
 
@@ -2134,6 +2139,16 @@ void QSslSocketPrivate::_q_flushWriteBuffer()
         q->flush();
 }
 
+/*!
+    \internal
+*/
+void QSslSocketPrivate::_q_flushReadBuffer()
+{
+    // trigger a read from the plainSocket into SSL
+    if (mode != QSslSocket::UnencryptedMode)
+        transmit();
+}
+
 QT_END_NAMESPACE
 
 // For private slots
diff --git a/src/network/ssl/qsslsocket.h b/src/network/ssl/qsslsocket.h
index adb206c..82cda35 100644
--- a/src/network/ssl/qsslsocket.h
+++ b/src/network/ssl/qsslsocket.h
@@ -207,6 +207,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_readyReadSlot())
     Q_PRIVATE_SLOT(d_func(), void _q_bytesWrittenSlot(qint64))
     Q_PRIVATE_SLOT(d_func(), void _q_flushWriteBuffer())
+    Q_PRIVATE_SLOT(d_func(), void _q_flushReadBuffer())
     friend class QSslSocketBackendPrivate;
 };
 
diff --git a/src/network/ssl/qsslsocket_p.h b/src/network/ssl/qsslsocket_p.h
index 24d4ebe..ee21956 100644
--- a/src/network/ssl/qsslsocket_p.h
+++ b/src/network/ssl/qsslsocket_p.h
@@ -120,6 +120,7 @@ public:
     void _q_readyReadSlot();
     void _q_bytesWrittenSlot(qint64);
     void _q_flushWriteBuffer();
+    void _q_flushReadBuffer();
 
     // Platform specific functions
     virtual void startClientEncryption() = 0;
diff --git a/tests/auto/qsslsocket/tst_qsslsocket.cpp b/tests/auto/qsslsocket/tst_qsslsocket.cpp
index d576201..2bd1684 100644
--- a/tests/auto/qsslsocket/tst_qsslsocket.cpp
+++ b/tests/auto/qsslsocket/tst_qsslsocket.cpp
@@ -170,6 +170,7 @@ private slots:
     void setEmptyKey();
     void spontaneousWrite();
     void setReadBufferSize();
+    void setReadBufferSize_task_250027();
     void waitForMinusOne();
     void verifyMode();
     void verifyDepth();
@@ -1241,6 +1242,66 @@ void tst_QSslSocket::setReadBufferSize()
     QVERIFY(receiver->bytesAvailable() > oldBytesAvailable);
 }
 
+class SetReadBufferSize_task_250027_handler : public QObject {
+    Q_OBJECT
+public slots:
+    void readyReadSlot() {
+        QTestEventLoop::instance().exitLoop();
+    }
+    void waitSomeMore(QSslSocket *socket) {
+        QTime t;
+        t.start();
+        while (!socket->encryptedBytesAvailable()) {
+            QCoreApplication::processEvents(QEventLoop::AllEvents | QEventLoop::WaitForMoreEvents, 250);
+            if (t.elapsed() > 1000 || socket->state() != QAbstractSocket::ConnectedState)
+                return;
+        }
+    }
+};
+
+void tst_QSslSocket::setReadBufferSize_task_250027()
+{
+    // do not execute this when a proxy is set.
+    QFETCH_GLOBAL(bool, setProxy);
+    if (setProxy)
+        return;
+
+    QSslSocketPtr socket = newSocket();
+    socket->setReadBufferSize(1000); // limit to 1 kb/sec
+    socket->ignoreSslErrors();
+    socket->connectToHostEncrypted(QtNetworkSettings::serverName(), 443);
+    socket->ignoreSslErrors();
+    QVERIFY(socket->waitForConnected(10*1000));
+    QVERIFY(socket->waitForEncrypted(10*1000));
+
+    // exit the event loop as soon as we receive a readyRead()
+    SetReadBufferSize_task_250027_handler setReadBufferSize_task_250027_handler;
+    connect(socket, SIGNAL(readyRead()), &setReadBufferSize_task_250027_handler, SLOT(readyReadSlot()));
+
+    // provoke a response by sending a request
+    socket->write("GET /gif/fluke.gif HTTP/1.0\n"); // this file is 27 KB
+    socket->write("Host: ");
+    socket->write(QtNetworkSettings::serverName().toLocal8Bit().constData());
+    socket->write("\n");
+    socket->write("Connection: close\n");
+    socket->write("\n");
+    socket->flush();
+
+    QTestEventLoop::instance().enterLoop(10);
+    setReadBufferSize_task_250027_handler.waitSomeMore(socket);
+    QByteArray firstRead = socket->readAll();
+    // First read should be some data, but not the whole file
+    QVERIFY(firstRead.size() > 0 && firstRead.size() < 20*1024);
+
+    QTestEventLoop::instance().enterLoop(10);
+    setReadBufferSize_task_250027_handler.waitSomeMore(socket);
+    QByteArray secondRead = socket->readAll();
+    // second read should be some more data
+    QVERIFY(secondRead.size() > 0);
+
+    socket->close();
+}
+
 class SslServer3 : public QTcpServer
 {
     Q_OBJECT