Improving junk packet handling for QUIC by ignoring packets with client

net/quic/quic_dispatcher.cc

Index: net/quic/quic_dispatcher.cc
diff --git a/net/quic/quic_dispatcher.cc b/net/quic/quic_dispatcher.cc
index ee2c0c6df2b1b0bb0dab2890e6260db87c1b59f0..f1ae7363fd57169cf903ca1d1f6a8b33469791d2 100644
--- a/net/quic/quic_dispatcher.cc
+++ b/net/quic/quic_dispatcher.cc
@@ -204,6 +204,13 @@ bool QuicDispatcher::OnUnauthenticatedPublicHeader(
     const QuicPacketPublicHeader& header) {
   QuicSession* session = nullptr;
 
+  // Port zero is only allowed for unidirectional UDP, so is disallowed by QUIC.
+  // Given that we can't even send a reply rejecting the packet, just black hole
+  // it.
+  if (current_client_address_.port() == 0) {
+    return false;
+  }
+
   QuicConnectionId connection_id = header.connection_id;
   SessionMap::iterator it = session_map_.find(connection_id);
   if (it == session_map_.end()) {