Make QUIC stateless rejects work in the face of packet loss by storing the SREJ packet(s) in the Qu…

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 260 matching lines @@
       migrating_peer_port_(0),
       last_packet_decrypted_(false),
       last_packet_revived_(false),
       last_size_(0),
       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),
       received_packet_manager_(&stats_),
       ack_queued_(false),
       num_packets_received_since_last_ack_sent_(0),
       stop_waiting_count_(0),
       delay_setting_retransmission_alarm_(false),
       pending_retransmission_alarm_(false),
       ack_alarm_(helper->CreateAlarm(new AckAlarm(this))),
       retransmission_alarm_(helper->CreateAlarm(new RetransmissionAlarm(this))),
       send_alarm_(helper->CreateAlarm(new SendAlarm(this))),
@@ skipping 43 matching lines @@
   SetMaxPacketLength(perspective_ == Perspective::IS_SERVER
                          ? kDefaultServerMaxPacketSize
                          : kDefaultMaxPacketSize);
 }
 
 QuicConnection::~QuicConnection() {
   if (owns_writer_) {
     delete writer_;
   }
   STLDeleteElements(&undecryptable_packets_);
+  if (termination_packets_.get() != nullptr) {
+    STLDeleteElements(termination_packets_.get());
+  }
   STLDeleteValues(&group_map_);
   ClearQueuedPackets();
 }
 
 void QuicConnection::ClearQueuedPackets() {
   for (QueuedPacketList::iterator it = queued_packets_.begin();
        it != queued_packets_.end(); ++it) {
     delete it->serialized_packet.retransmittable_frames;
     delete it->serialized_packet.packet;
   }
@@ skipping 1136 matching lines @@
                 << 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) {
+  // Termination packets are encrypted and saved, so don't exit early.
+  const bool is_termination_packet = IsTerminationPacket(*packet);
+  if (writer_->IsWriteBlocked() && !is_termination_packet) {
     return false;
   }
 
   QuicPacketNumber packet_number = packet->serialized_packet.packet_number;
   DCHECK_LE(packet_number_of_last_sent_packet_, packet_number);
   packet_number_of_last_sent_packet_ = packet_number;
 
   QuicEncryptedPacket* encrypted = packet->serialized_packet.packet;
-  // Connection close packets are eventually owned by TimeWaitListManager.
+  // Termination packets are eventually owned by TimeWaitListManager.
   // Others are deleted at the end of this call.
-  if (is_connection_close) {
-    DCHECK(connection_close_packet_.get() == nullptr);
+  if (is_termination_packet) {
+    if (termination_packets_.get() == nullptr) {
+      termination_packets_.reset(new std::vector<QuicEncryptedPacket*>);
+    }
     // Clone the packet so it's owned in the future.
-    connection_close_packet_.reset(encrypted->Clone());
+    termination_packets_->push_back(encrypted->Clone());
     // This assures we won't try to write *forced* packets when blocked.
     // Return true to stop processing.
     if (writer_->IsWriteBlocked()) {
       visitor_->OnWriteBlocked();
       return true;
     }
   }
 
   DCHECK_LE(encrypted->length(), kMaxPacketSize);
   DCHECK_LE(encrypted->length(), packet_generator_.GetMaxPacketLength());
@@ skipping 490 matching lines @@
 void QuicConnection::SetMaxPacketLength(QuicByteCount length) {
   return packet_generator_.SetMaxPacketLength(LimitMaxPacketSize(length),
                                               /*force=*/false);
 }
 
 bool QuicConnection::HasQueuedData() const {
   return pending_version_negotiation_packet_ ||
       !queued_packets_.empty() || packet_generator_.HasQueuedFrames();
 }
 
+void QuicConnection::EnableSavingCryptoPackets() {
+  save_crypto_packets_as_termination_packets_ = true;
+}
+
 bool QuicConnection::CanWriteStreamData() {
   // Don't write stream data if there are negotiation or queued data packets
   // to send. Otherwise, continue and bundle as many frames as possible.
   if (pending_version_negotiation_packet_ || !queued_packets_.empty()) {
     return false;
   }
 
   IsHandshake pending_handshake = visitor_->HasPendingHandshake() ?
       IS_HANDSHAKE : NOT_HANDSHAKE;
   // Sending queued packets may have caused the socket to become write blocked,
@@ skipping 184 matching lines @@
   // Retransmitted packets retransmittable frames are owned by the unacked
   // packet map, but are not present in the serialized packet.
   if (packet.transmission_type != NOT_RETRANSMISSION ||
       packet.serialized_packet.retransmittable_frames != nullptr) {
     return HAS_RETRANSMITTABLE_DATA;
   } else {
     return NO_RETRANSMITTABLE_DATA;
   }
 }
 
-bool QuicConnection::IsConnectionClose(const QueuedPacket& packet) {
+bool QuicConnection::IsTerminationPacket(const QueuedPacket& packet) {
   const RetransmittableFrames* retransmittable_frames =
       packet.serialized_packet.retransmittable_frames;
   if (retransmittable_frames == nullptr) {
     return false;
   }
   for (const QuicFrame& frame : retransmittable_frames->frames()) {
     if (frame.type == CONNECTION_CLOSE_FRAME) {
       return true;
     }
+    if (save_crypto_packets_as_termination_packets_ &&
+        frame.type == STREAM_FRAME &&
+        frame.stream_frame->stream_id == kCryptoStreamId) {
+      return true;
+    }
   }
   return false;
 }
 
 void QuicConnection::SetMtuDiscoveryTarget(QuicByteCount target) {
   mtu_discovery_target_ = LimitMaxPacketSize(target);
 }
 
 QuicByteCount QuicConnection::LimitMaxPacketSize(
     QuicByteCount suggested_max_packet_size) {
@@ skipping 47 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