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