Improving junk packet handling for QUIC by ignoring packets with client

net/tools/quic/quic_dispatcher.cc

Index: net/tools/quic/quic_dispatcher.cc
diff --git a/net/tools/quic/quic_dispatcher.cc b/net/tools/quic/quic_dispatcher.cc
index 1771026c97a765f515c23e9813c185cb2d294149..46f672ea0f100e0a4952362367da51fa4b450e47 100644
--- a/net/tools/quic/quic_dispatcher.cc
+++ b/net/tools/quic/quic_dispatcher.cc
@@ -209,6 +209,13 @@ 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()) {