Merge pull request #7398 from huffman/add-request-handshake

Add HandshakeRequest packet

libraries/networking/src/udt/Connection.cpp

@@ -411,7 +411,15 @@ SequenceNumber Connection::nextACK() const {
 bool Connection::processReceivedSequenceNumber(SequenceNumber sequenceNumber, int packetSize, int payloadSize) {
     
     if (!_hasReceivedHandshake) {
-        // refuse to process any packets until we've received the handshake
+        // Refuse to process any packets until we've received the handshake
+        // Send handshake request to re-request a handshake
+        auto handshakeRequestPacket = ControlPacket::create(ControlPacket::HandshakeRequest, 0);
+        _parentSocket->writeBasePacket(*handshakeRequestPacket, _destination);
+
+#ifdef UDT_CONNECTION_DEBUG
+        qCDebug(networking) << "Received packet before receiving handshake, sending HandshakeRequest";
+#endif
+
         return false;
     }
     
@@ -537,6 +545,17 @@ void Connection::processControl(std::unique_ptr<ControlPacket> controlPacket) {
                 processProbeTail(move(controlPacket));
             }
             break;
+        case ControlPacket::HandshakeRequest:
+            if (_hasReceivedHandshakeACK) {
+                // We're already in a state where we've received a handshake ack, so we are likely in a state
+                // where the other end expired our connection. Let's reset.
+
+#ifdef UDT_CONNECTION_DEBUG
+                qCDebug(networking) << "Got handshake request, stopping SendQueue";
+#endif
+                stopSendQueue();
+            }
+            break;
     }
 }
 

libraries/networking/src/udt/ControlPacket.cpp

@@ -100,7 +100,7 @@ void ControlPacket::readType() {
     Q_ASSERT_X(bitAndType & CONTROL_BIT_MASK, "ControlPacket::readHeader()", "This should be a control packet");
     
     uint16_t packetType = (bitAndType & ~CONTROL_BIT_MASK) >> (8 * sizeof(Type));
-    Q_ASSERT_X(packetType <= ControlPacket::Type::ProbeTail, "ControlPacket::readType()", "Received a control packet with wrong type");
+    Q_ASSERT_X(packetType <= ControlPacket::Type::HandshakeRequest, "ControlPacket::readType()", "Received a control packet with wrong type");
     
     // read the type
     _type = (Type) packetType;

libraries/networking/src/udt/ControlPacket.h

@@ -34,7 +34,8 @@ public:
         TimeoutNAK,
         Handshake,
         HandshakeACK,
-        ProbeTail
+        ProbeTail,
+        HandshakeRequest
     };
     
     static std::unique_ptr<ControlPacket> create(Type type, qint64 size = -1);

libraries/networking/src/udt/SendQueue.cpp

@@ -529,4 +529,4 @@ void SendQueue::deactivate() {
     emit queueInactive();
     
     _state = State::Stopped;
-}
+}