Add a new QUIC connection option, 5RTO, which closes the QUIC connection after 5 consecutive RTOs. …

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 217 matching lines @@
       last_size_(0),
       current_packet_data_(nullptr),
       last_decrypted_packet_level_(ENCRYPTION_NONE),
       should_last_packet_instigate_acks_(false),
       largest_seen_packet_with_ack_(0),
       largest_seen_packet_with_stop_waiting_(0),
       max_undecryptable_packets_(0),
       pending_version_negotiation_packet_(false),
       save_crypto_packets_as_termination_packets_(false),
       silent_close_enabled_(false),
+      close_connection_after_five_rtos_(false),
       received_packet_manager_(&stats_),
       ack_queued_(false),
       num_retransmittable_packets_received_since_last_ack_sent_(0),
       last_ack_had_missing_packets_(false),
       num_packets_received_since_last_ack_sent_(0),
       stop_waiting_count_(0),
       ack_mode_(TCP_ACKING),
       delay_setting_retransmission_alarm_(false),
       pending_retransmission_alarm_(false),
       defer_send_in_response_to_packets_(false),
@@ skipping 115 matching lines @@
   if (debug_visitor_ != nullptr) {
     debug_visitor_->OnSetFromConfig(config);
   }
   if (config.HasClientSentConnectionOption(kACKD, perspective_)) {
     ack_mode_ = ACK_DECIMATION;
   }
   if (FLAGS_quic_ack_decimation2 &&
       config.HasClientSentConnectionOption(kAKD2, perspective_)) {
     ack_mode_ = ACK_DECIMATION_WITH_REORDERING;
   }
+  if (FLAGS_quic_enable_rto_timeout &&
+      config.HasClientSentConnectionOption(k5RTO, perspective_)) {
+    close_connection_after_five_rtos_ = true;
+  }
 }
 
 void QuicConnection::OnSendConnectionState(
     const CachedNetworkParameters& cached_network_params) {
   if (debug_visitor_ != nullptr) {
     debug_visitor_->OnSendConnectionState(cached_network_params);
   }
 }
 
 void QuicConnection::OnReceiveConnectionState(
@@ skipping 1392 matching lines @@
   num_packets_received_since_last_ack_sent_ = 0;
 
   packet_generator_.SetShouldSendAck(true);
 }
 
 void QuicConnection::OnRetransmissionTimeout() {
   if (!sent_packet_manager_.HasUnackedPackets()) {
     return;
   }
 
+  if (close_connection_after_five_rtos_ &&
+      sent_packet_manager_.consecutive_rto_count() >= 4) {
+    // Close on the 5th consecutive RTO, so after 4 previous RTOs have occurred.
+    SendConnectionCloseWithDetails(QUIC_TOO_MANY_RTOS,
+                                   "5 consecutive retransmission timeouts");
+    return;
+  }
+
   sent_packet_manager_.OnRetransmissionTimeout();
   WriteIfNotBlocked();
 
   // A write failure can result in the connection being closed, don't attempt to
   // write further packets, or to set alarms.
   if (!connected_) {
     return;
   }
 
   // In the TLP case, the SentPacketManager gives the connection the opportunity
@@ skipping 541 matching lines @@
 }
 
 StringPiece QuicConnection::GetCurrentPacket() {
   if (current_packet_data_ == nullptr) {
     return StringPiece();
   }
   return StringPiece(current_packet_data_, last_size_);
 }
 
 }  // namespace net