relnote: Close the QUIC connection when a packet is about to be sent out

net/quic/quic_connection.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
@@ skipping 1597 matching lines @@
     return false;
   }
   delete packet->serialized_packet.retransmittable_frames;
   delete packet->serialized_packet.packet;
   packet->serialized_packet.retransmittable_frames = nullptr;
   packet->serialized_packet.packet = nullptr;
   return true;
 }
 
 bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
+  if (FLAGS_quic_close_connection_out_of_order_sending &&
+      packet->serialized_packet.packet_number <
+          sent_packet_manager_.largest_sent_packet()) {
+    LOG(DFATAL) << "Attempt to write packet:"
+                << packet->serialized_packet.packet_number
+                << " after:" << sent_packet_manager_.largest_sent_packet();
+    SendConnectionCloseWithDetails(QUIC_INTERNAL_ERROR,
+                                   "Packet written out of order.");
+    return true;
+  }
   if (ShouldDiscardPacket(*packet)) {
     ++stats_.packets_discarded;
     return true;
   }
   // Connection close packets are encrypted and saved, so don't exit early.
   const bool is_connection_close = IsConnectionClose(*packet);
   if (writer_->IsWriteBlocked() && !is_connection_close) {
     return false;
   }
 
@@ skipping 768 matching lines @@
       packet_number_of_last_sent_packet_ + packets_between_mtu_probes_ + 1;
   ++mtu_probe_count_;
 
   DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
   SendMtuDiscoveryPacket(mtu_discovery_target_);
 
   DCHECK(!mtu_discovery_alarm_->IsSet());
 }
 
 }  // namespace net