net/tools/quic/quic_server_session.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/tools/quic/quic_server_session.h"
   6
   7 #include "base/logging.h"
   8 #include "net/quic/crypto/cached_network_parameters.h"
   9 #include "net/quic/quic_connection.h"
  10 #include "net/quic/quic_flags.h"
  11 #include "net/quic/reliable_quic_stream.h"
  12 #include "net/tools/quic/quic_spdy_server_stream.h"
  13
  14 namespace net {
  15 namespace tools {
  16
  17 QuicServerSession::QuicServerSession(const QuicConfig& config,
  18                                      QuicConnection* connection,
  19                                      QuicServerSessionVisitor* visitor)
  20     : QuicSession(connection, config),
  21       visitor_(visitor),
  22       bandwidth_estimate_sent_to_client_(QuicBandwidth::Zero()),
  23       last_scup_time_(QuicTime::Zero()),
  24       last_scup_sequence_number_(0) {}
  25
  26 QuicServerSession::~QuicServerSession() {}
  27
  28 void QuicServerSession::InitializeSession(
  29     const QuicCryptoServerConfig& crypto_config) {
  30   QuicSession::InitializeSession();
  31   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config));
  32 }
  33
  34 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
  35     const QuicCryptoServerConfig& crypto_config) {
  36   return new QuicCryptoServerStream(crypto_config, this);
  37 }
  38
  39 void QuicServerSession::OnConfigNegotiated() {
  40   QuicSession::OnConfigNegotiated();
  41
  42   if (!config()->HasReceivedConnectionOptions()) {
  43     return;
  44   }
  45
  46   // If the client has provided a bandwidth estimate from the same serving
  47   // region, then pass it to the sent packet manager in preparation for possible
  48   // bandwidth resumption.
  49   const CachedNetworkParameters* cached_network_params =
  50       crypto_stream_->previous_cached_network_params();
  51   if (FLAGS_quic_enable_bandwidth_resumption_experiment &&
  52       cached_network_params != nullptr &&
  53       ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWRE) &&
  54       cached_network_params->serving_region() == serving_region_) {
  55     connection()->ResumeConnectionState(*cached_network_params);
  56   }
  57
  58   if (FLAGS_enable_quic_fec &&
  59       ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  60     // kFHDR config maps to FEC protection always for headers stream.
  61     // TODO(jri): Add crypto stream in addition to headers for kHDR.
  62     headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
  63   }
  64 }
  65
  66 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  67                                            bool from_peer) {
  68   QuicSession::OnConnectionClosed(error, from_peer);
  69   // In the unlikely event we get a connection close while doing an asynchronous
  70   // crypto event, make sure we cancel the callback.
  71   if (crypto_stream_.get() != nullptr) {
  72     crypto_stream_->CancelOutstandingCallbacks();
  73   }
  74   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  75 }
  76
  77 void QuicServerSession::OnWriteBlocked() {
  78   QuicSession::OnWriteBlocked();
  79   visitor_->OnWriteBlocked(connection());
  80 }
  81
  82 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  83   if (connection()->version() <= QUIC_VERSION_21) {
  84     return;
  85   }
  86
  87   // Only send updates when the application has no data to write.
  88   if (HasDataToWrite()) {
  89     return;
  90   }
  91
  92   // If not enough time has passed since the last time we sent an update to the
  93   // client, or not enough packets have been sent, then return early.
  94   const QuicSentPacketManager& sent_packet_manager =
  95       connection()->sent_packet_manager();
  96   int64 srtt_ms =
  97       sent_packet_manager.GetRttStats()->smoothed_rtt().ToMilliseconds();
  98   int64 now_ms = now.Subtract(last_scup_time_).ToMilliseconds();
  99   int64 packets_since_last_scup =
 100       connection()->sequence_number_of_last_sent_packet() -
 101       last_scup_sequence_number_;
 102   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
 103       now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
 104       packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
 105     return;
 106   }
 107
 108   // If the bandwidth recorder does not have a valid estimate, return early.
 109   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
 110       sent_packet_manager.SustainedBandwidthRecorder();
 111   if (!bandwidth_recorder.HasEstimate()) {
 112     return;
 113   }
 114
 115   // The bandwidth recorder has recorded at least one sustained bandwidth
 116   // estimate. Check that it's substantially different from the last one that
 117   // we sent to the client, and if so, send the new one.
 118   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
 119
 120   int64 bandwidth_delta =
 121       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
 122                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
 123
 124   // Define "substantial" difference as a 50% increase or decrease from the
 125   // last estimate.
 126   bool substantial_difference =
 127       bandwidth_delta >
 128       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 129   if (!substantial_difference) {
 130     return;
 131   }
 132
 133   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 134   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 135            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 136
 137   // Include max bandwidth in the update.
 138   QuicBandwidth max_bandwidth_estimate =
 139       bandwidth_recorder.MaxBandwidthEstimate();
 140   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 141
 142   // Fill the proto before passing it to the crypto stream to send.
 143   CachedNetworkParameters cached_network_params;
 144   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 145       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 146   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 147       max_bandwidth_estimate.ToBytesPerSecond());
 148   cached_network_params.set_max_bandwidth_timestamp_seconds(
 149       max_bandwidth_timestamp);
 150   cached_network_params.set_min_rtt_ms(
 151       sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
 152   cached_network_params.set_previous_connection_state(
 153       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 154           ? CachedNetworkParameters::SLOW_START
 155           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 156   cached_network_params.set_timestamp(
 157       connection()->clock()->WallNow().ToUNIXSeconds());
 158   if (!serving_region_.empty()) {
 159     cached_network_params.set_serving_region(serving_region_);
 160   }
 161
 162   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
 163   last_scup_time_ = now;
 164   last_scup_sequence_number_ =
 165       connection()->sequence_number_of_last_sent_packet();
 166 }
 167
 168 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
 169   if (id % 2 == 0) {
 170     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 171     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 172     return false;
 173   }
 174   if (GetNumOpenStreams() >= get_max_open_streams()) {
 175     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 176              << " Already " << GetNumOpenStreams() << " streams open (max "
 177              << get_max_open_streams() << ").";
 178     connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 179     return false;
 180   }
 181   return true;
 182 }
 183
 184 QuicDataStream* QuicServerSession::CreateIncomingDataStream(
 185     QuicStreamId id) {
 186   if (!ShouldCreateIncomingDataStream(id)) {
 187     return nullptr;
 188   }
 189
 190   return new QuicSpdyServerStream(id, this);
 191 }
 192
 193 QuicDataStream* QuicServerSession::CreateOutgoingDataStream() {
 194   DLOG(ERROR) << "Server push not yet supported";
 195   return nullptr;
 196 }
 197
 198 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 199   return crypto_stream_.get();
 200 }
 201
 202 }  // namespace tools
 203 }  // namespace net