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(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   const bool max_bandwidth_resumption =
  52       ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWMX);
  53   if (cached_network_params != nullptr &&
  54       (ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWRE) ||
  55        max_bandwidth_resumption) &&
  56       cached_network_params->serving_region() == serving_region_) {
  57     connection()->ResumeConnectionState(*cached_network_params,
  58                                         max_bandwidth_resumption);
  59   }
  60
  61   if (FLAGS_enable_quic_fec &&
  62       ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  63     // kFHDR config maps to FEC protection always for headers stream.
  64     // TODO(jri): Add crypto stream in addition to headers for kHDR.
  65     headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
  66   }
  67 }
  68
  69 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  70                                            bool from_peer) {
  71   QuicSession::OnConnectionClosed(error, from_peer);
  72   // In the unlikely event we get a connection close while doing an asynchronous
  73   // crypto event, make sure we cancel the callback.
  74   if (crypto_stream_.get() != nullptr) {
  75     crypto_stream_->CancelOutstandingCallbacks();
  76   }
  77   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  78 }
  79
  80 void QuicServerSession::OnWriteBlocked() {
  81   QuicSession::OnWriteBlocked();
  82   visitor_->OnWriteBlocked(connection());
  83 }
  84
  85 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  86   // Only send updates when the application has no data to write.
  87   if (HasDataToWrite()) {
  88     return;
  89   }
  90
  91   // If not enough time has passed since the last time we sent an update to the
  92   // client, or not enough packets have been sent, then return early.
  93   const QuicSentPacketManager& sent_packet_manager =
  94       connection()->sent_packet_manager();
  95   int64 srtt_ms =
  96       sent_packet_manager.GetRttStats()->smoothed_rtt().ToMilliseconds();
  97   int64 now_ms = now.Subtract(last_scup_time_).ToMilliseconds();
  98   int64 packets_since_last_scup =
  99       connection()->sequence_number_of_last_sent_packet() -
 100       last_scup_sequence_number_;
 101   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
 102       now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
 103       packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
 104     return;
 105   }
 106
 107   // If the bandwidth recorder does not have a valid estimate, return early.
 108   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
 109       sent_packet_manager.SustainedBandwidthRecorder();
 110   if (!bandwidth_recorder.HasEstimate()) {
 111     return;
 112   }
 113
 114   // The bandwidth recorder has recorded at least one sustained bandwidth
 115   // estimate. Check that it's substantially different from the last one that
 116   // we sent to the client, and if so, send the new one.
 117   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
 118
 119   int64 bandwidth_delta =
 120       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
 121                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
 122
 123   // Define "substantial" difference as a 50% increase or decrease from the
 124   // last estimate.
 125   bool substantial_difference =
 126       bandwidth_delta >
 127       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 128   if (!substantial_difference) {
 129     return;
 130   }
 131
 132   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 133   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 134            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 135
 136   // Include max bandwidth in the update.
 137   QuicBandwidth max_bandwidth_estimate =
 138       bandwidth_recorder.MaxBandwidthEstimate();
 139   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 140
 141   // Fill the proto before passing it to the crypto stream to send.
 142   CachedNetworkParameters cached_network_params;
 143   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 144       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 145   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 146       max_bandwidth_estimate.ToBytesPerSecond());
 147   cached_network_params.set_max_bandwidth_timestamp_seconds(
 148       max_bandwidth_timestamp);
 149   cached_network_params.set_min_rtt_ms(
 150       sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
 151   cached_network_params.set_previous_connection_state(
 152       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 153           ? CachedNetworkParameters::SLOW_START
 154           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 155   cached_network_params.set_timestamp(
 156       connection()->clock()->WallNow().ToUNIXSeconds());
 157   if (!serving_region_.empty()) {
 158     cached_network_params.set_serving_region(serving_region_);
 159   }
 160
 161   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
 162
 163   connection()->OnSendConnectionState(cached_network_params);
 164
 165   last_scup_time_ = now;
 166   last_scup_sequence_number_ =
 167       connection()->sequence_number_of_last_sent_packet();
 168 }
 169
 170 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
 171   if (id % 2 == 0) {
 172     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 173     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 174     return false;
 175   }
 176   if (GetNumOpenStreams() >= get_max_open_streams()) {
 177     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 178              << " Already " << GetNumOpenStreams() << " streams open (max "
 179              << get_max_open_streams() << ").";
 180     connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 181     return false;
 182   }
 183   return true;
 184 }
 185
 186 QuicDataStream* QuicServerSession::CreateIncomingDataStream(
 187     QuicStreamId id) {
 188   if (!ShouldCreateIncomingDataStream(id)) {
 189     return nullptr;
 190   }
 191
 192   return new QuicSpdyServerStream(id, this);
 193 }
 194
 195 QuicDataStream* QuicServerSession::CreateOutgoingDataStream() {
 196   DLOG(ERROR) << "Server push not yet supported";
 197   return nullptr;
 198 }
 199
 200 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 201   return crypto_stream_.get();
 202 }
 203
 204 }  // namespace tools
 205 }  // namespace net