Close the QUIC connection if too many sent or received packets are

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>
 #include <iterator>
 #include <limits>
 #include <memory>
 #include <set>
 #include <utility>
 
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
+#include "base/strings/stringprintf.h"
 #include "net/base/net_errors.h"
 #include "net/quic/crypto/quic_decrypter.h"
 #include "net/quic/crypto/quic_encrypter.h"
 #include "net/quic/iovector.h"
 #include "net/quic/quic_bandwidth.h"
 #include "net/quic/quic_config.h"
 #include "net/quic/quic_fec_group.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/quic_utils.h"
 
 using base::StringPiece;
+using base::StringPrintf;
 using base::hash_map;
 using base::hash_set;
 using std::list;
 using std::make_pair;
 using std::max;
 using std::min;
 using std::numeric_limits;
 using std::set;
 using std::string;
 using std::vector;
 
 namespace net {
 
 class QuicDecrypter;
 class QuicEncrypter;
 
 namespace {
 
 // The largest gap in packets we'll accept without closing the connection.
 // This will likely have to be tuned.
 const QuicPacketSequenceNumber kMaxPacketGap = 5000;
 
 // Limit the number of FEC groups to two.  If we get enough out of order packets
 // that this becomes limiting, we can revisit.
 const size_t kMaxFecGroups = 2;
 
 // Maximum number of acks received before sending an ack in response.
 const size_t kMaxPacketsReceivedBeforeAckSend = 20;
 
+// Maximum number of tracked packets.
+const size_t kMaxTrackedPackets = 5 * kMaxTcpCongestionWindow;;
+
 bool Near(QuicPacketSequenceNumber a, QuicPacketSequenceNumber b) {
   QuicPacketSequenceNumber delta = (a > b) ? a - b : b - a;
   return delta <= kMaxPacketGap;
 }
 
 // An alarm that is scheduled to send an ack if a timeout occurs.
 class AckAlarm : public QuicAlarm::Delegate {
  public:
   explicit AckAlarm(QuicConnection* connection)
       : connection_(connection) {
@@ skipping 805 matching lines @@
     DCHECK(!connected_);
   }
 
   // If there are new missing packets to report, send an ack immediately.
   if (received_packet_manager_.HasNewMissingPackets()) {
     ack_queued_ = true;
     ack_alarm_->Cancel();
   }
 
   UpdateStopWaitingCount();
-
   ClearLastFrames();
+  MaybeCloseIfTooManyOutstandingPackets();
 }
 
 void QuicConnection::MaybeQueueAck() {
   // If the incoming packet was missing, send an ack immediately.
   ack_queued_ = received_packet_manager_.IsMissing(
       last_header_.packet_sequence_number);
 
   if (!ack_queued_ && ShouldLastPacketInstigateAck()) {
     if (ack_alarm_->IsSet()) {
       ack_queued_ = true;
@@ skipping 20 matching lines @@
   last_congestion_frames_.clear();
   last_stop_waiting_frames_.clear();
   last_rst_frames_.clear();
   last_goaway_frames_.clear();
   last_window_update_frames_.clear();
   last_blocked_frames_.clear();
   last_ping_frames_.clear();
   last_close_frames_.clear();
 }
 
+void QuicConnection::MaybeCloseIfTooManyOutstandingPackets() {
+  if (!FLAGS_quic_too_many_outstanding_packets) {
+    return;
+  }
+  // This occurs if we don't discard old packets we've sent fast enough.
+  // It's possible largest observed is less than least unacked.
+  if (sent_packet_manager_.largest_observed() >
+          (sent_packet_manager_.GetLeastUnacked() + kMaxTrackedPackets)) {
+    SendConnectionCloseWithDetails(
+        QUIC_TOO_MANY_OUTSTANDING_SENT_PACKETS,
+        StringPrintf("More than %zu outstanding.", kMaxTrackedPackets));
+  }
+  // This occurs if there are received packet gaps and the peer does not raise
+  // the least unacked fast enough.
+  if (received_packet_manager_.NumTrackedPackets() > kMaxTrackedPackets) {
+    SendConnectionCloseWithDetails(
+        QUIC_TOO_MANY_OUTSTANDING_RECEIVED_PACKETS,
+        StringPrintf("More than %zu outstanding.", kMaxTrackedPackets));
+  }
+}
+
 QuicAckFrame* QuicConnection::CreateAckFrame() {
   QuicAckFrame* outgoing_ack = new QuicAckFrame();
   received_packet_manager_.UpdateReceivedPacketInfo(
       outgoing_ack, clock_->ApproximateNow());
   DVLOG(1) << ENDPOINT << "Creating ack frame: " << *outgoing_ack;
   return outgoing_ack;
 }
 
 QuicCongestionFeedbackFrame* QuicConnection::CreateFeedbackFrame() {
   return new QuicCongestionFeedbackFrame(outgoing_congestion_feedback_);
@@ skipping 1110 matching lines @@
   }
   for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
     if (retransmittable_frames->frames()[i].type == CONNECTION_CLOSE_FRAME) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace net