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/proto/cached_network_parameters.pb.h"
   9 #include "net/quic/quic_connection.h"
  10 #include "net/quic/quic_flags.h"
  11 #include "net/quic/quic_spdy_session.h"
  12 #include "net/quic/reliable_quic_stream.h"
  13 #include "net/tools/quic/quic_spdy_server_stream.h"
  14
  15 namespace net {
  16 namespace tools {
  17
  18 QuicServerSession::QuicServerSession(
  19     const QuicConfig& config,
  20     QuicConnection* connection,
  21     QuicServerSessionVisitor* visitor,
  22     const QuicCryptoServerConfig* crypto_config)
  23     : QuicSpdySession(connection, config),
  24       crypto_config_(crypto_config),
  25       visitor_(visitor),
  26       bandwidth_resumption_enabled_(false),
  27       bandwidth_estimate_sent_to_client_(QuicBandwidth::Zero()),
  28       last_scup_time_(QuicTime::Zero()),
  29       last_scup_packet_number_(0) {}
  30
  31 QuicServerSession::~QuicServerSession() {}
  32
  33 void QuicServerSession::Initialize() {
  34   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config_));
  35   QuicSpdySession::Initialize();
  36 }
  37
  38 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
  39     const QuicCryptoServerConfig* crypto_config) {
  40   return new QuicCryptoServerStream(crypto_config, this);
  41 }
  42
  43 void QuicServerSession::OnConfigNegotiated() {
  44   QuicSession::OnConfigNegotiated();
  45
  46   if (!config()->HasReceivedConnectionOptions()) {
  47     return;
  48   }
  49
  50   // If the client has provided a bandwidth estimate from the same serving
  51   // region, then pass it to the sent packet manager in preparation for possible
  52   // bandwidth resumption.
  53   const CachedNetworkParameters* cached_network_params =
  54       crypto_stream_->previous_cached_network_params();
  55   const bool last_bandwidth_resumption =
  56       ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWRE);
  57   const bool max_bandwidth_resumption =
  58       ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWMX);
  59   bandwidth_resumption_enabled_ =
  60       last_bandwidth_resumption || max_bandwidth_resumption;
  61   if (cached_network_params != nullptr && bandwidth_resumption_enabled_ &&
  62       cached_network_params->serving_region() == serving_region_) {
  63     int64 seconds_since_estimate =
  64         connection()->clock()->WallNow().ToUNIXSeconds() -
  65         cached_network_params->timestamp();
  66     bool estimate_within_last_hour =
  67         seconds_since_estimate <= kNumSecondsPerHour;
  68     if (estimate_within_last_hour) {
  69       connection()->ResumeConnectionState(*cached_network_params,
  70                                           max_bandwidth_resumption);
  71     }
  72   }
  73
  74   if (FLAGS_enable_quic_fec &&
  75       ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  76     // kFHDR config maps to FEC protection always for headers stream.
  77     // TODO(jri): Add crypto stream in addition to headers for kHDR.
  78     headers_stream()->set_fec_policy(FEC_PROTECT_ALWAYS);
  79   }
  80 }
  81
  82 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  83                                            bool from_peer) {
  84   QuicSession::OnConnectionClosed(error, from_peer);
  85   // In the unlikely event we get a connection close while doing an asynchronous
  86   // crypto event, make sure we cancel the callback.
  87   if (crypto_stream_.get() != nullptr) {
  88     crypto_stream_->CancelOutstandingCallbacks();
  89   }
  90   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  91 }
  92
  93 void QuicServerSession::OnWriteBlocked() {
  94   QuicSession::OnWriteBlocked();
  95   visitor_->OnWriteBlocked(connection());
  96 }
  97
  98 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  99   if (!bandwidth_resumption_enabled_) {
 100     return;
 101   }
 102   // Only send updates when the application has no data to write.
 103   if (HasDataToWrite()) {
 104     return;
 105   }
 106
 107   // If not enough time has passed since the last time we sent an update to the
 108   // client, or not enough packets have been sent, then return early.
 109   const QuicSentPacketManager& sent_packet_manager =
 110       connection()->sent_packet_manager();
 111   int64 srtt_ms =
 112       sent_packet_manager.GetRttStats()->smoothed_rtt().ToMilliseconds();
 113   int64 now_ms = now.Subtract(last_scup_time_).ToMilliseconds();
 114   int64 packets_since_last_scup =
 115       connection()->packet_number_of_last_sent_packet() -
 116       last_scup_packet_number_;
 117   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
 118       now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
 119       packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
 120     return;
 121   }
 122
 123   // If the bandwidth recorder does not have a valid estimate, return early.
 124   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
 125       sent_packet_manager.SustainedBandwidthRecorder();
 126   if (!bandwidth_recorder.HasEstimate()) {
 127     return;
 128   }
 129
 130   // The bandwidth recorder has recorded at least one sustained bandwidth
 131   // estimate. Check that it's substantially different from the last one that
 132   // we sent to the client, and if so, send the new one.
 133   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
 134
 135   int64 bandwidth_delta =
 136       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
 137                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
 138
 139   // Define "substantial" difference as a 50% increase or decrease from the
 140   // last estimate.
 141   bool substantial_difference =
 142       bandwidth_delta >
 143       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 144   if (!substantial_difference) {
 145     return;
 146   }
 147
 148   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 149   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 150            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 151
 152   // Include max bandwidth in the update.
 153   QuicBandwidth max_bandwidth_estimate =
 154       bandwidth_recorder.MaxBandwidthEstimate();
 155   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 156
 157   // Fill the proto before passing it to the crypto stream to send.
 158   CachedNetworkParameters cached_network_params;
 159   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 160       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 161   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 162       max_bandwidth_estimate.ToBytesPerSecond());
 163   cached_network_params.set_max_bandwidth_timestamp_seconds(
 164       max_bandwidth_timestamp);
 165   cached_network_params.set_min_rtt_ms(
 166       sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
 167   cached_network_params.set_previous_connection_state(
 168       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 169           ? CachedNetworkParameters::SLOW_START
 170           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 171   cached_network_params.set_timestamp(
 172       connection()->clock()->WallNow().ToUNIXSeconds());
 173   if (!serving_region_.empty()) {
 174     cached_network_params.set_serving_region(serving_region_);
 175   }
 176
 177   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
 178
 179   connection()->OnSendConnectionState(cached_network_params);
 180
 181   last_scup_time_ = now;
 182   last_scup_packet_number_ = connection()->packet_number_of_last_sent_packet();
 183 }
 184
 185 bool QuicServerSession::ShouldCreateIncomingDynamicStream(QuicStreamId id) {
 186   if (!connection()->connected()) {
 187     LOG(DFATAL) << "ShouldCreateIncomingDynamicStream called when disconnected";
 188     return false;
 189   }
 190
 191   if (id % 2 == 0) {
 192     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 193     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 194     return false;
 195   }
 196   if (!FLAGS_exact_stream_id_delta) {
 197     if (GetNumOpenStreams() >= get_max_open_streams()) {
 198       DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 199                << " Already " << GetNumOpenStreams() << " streams open (max "
 200                << get_max_open_streams() << ").";
 201       connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 202       return false;
 203     }
 204   }
 205   return true;
 206 }
 207
 208 QuicDataStream* QuicServerSession::CreateIncomingDynamicStream(
 209     QuicStreamId id) {
 210   if (!ShouldCreateIncomingDynamicStream(id)) {
 211     return nullptr;
 212   }
 213
 214   return new QuicSpdyServerStream(id, this);
 215 }
 216
 217 QuicDataStream* QuicServerSession::CreateOutgoingDynamicStream() {
 218   DLOG(ERROR) << "Server push not yet supported";
 219   return nullptr;
 220 }
 221
 222 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 223   return crypto_stream_.get();
 224 }
 225
 226 }  // namespace tools
 227 }  // namespace net