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/source_address_token.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_server_config_update_time_(QuicTime::Zero()) {}
  24
  25 QuicServerSession::~QuicServerSession() {}
  26
  27 void QuicServerSession::InitializeSession(
  28     const QuicCryptoServerConfig& crypto_config) {
  29   QuicSession::InitializeSession();
  30   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config));
  31 }
  32
  33 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
  34     const QuicCryptoServerConfig& crypto_config) {
  35   return new QuicCryptoServerStream(crypto_config, this);
  36 }
  37
  38 void QuicServerSession::OnConfigNegotiated() {
  39   QuicSession::OnConfigNegotiated();
  40   if (!FLAGS_enable_quic_fec ||
  41       !config()->HasReceivedConnectionOptions() ||
  42       !net::ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  43     return;
  44   }
  45   // kFHDR config maps to FEC protection always for headers stream.
  46   // TODO(jri): Add crypto stream in addition to headers for kHDR.
  47   headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
  48 }
  49
  50 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  51                                            bool from_peer) {
  52   QuicSession::OnConnectionClosed(error, from_peer);
  53   // In the unlikely event we get a connection close while doing an asynchronous
  54   // crypto event, make sure we cancel the callback.
  55   if (crypto_stream_.get() != NULL) {
  56     crypto_stream_->CancelOutstandingCallbacks();
  57   }
  58   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  59 }
  60
  61 void QuicServerSession::OnWriteBlocked() {
  62   QuicSession::OnWriteBlocked();
  63   visitor_->OnWriteBlocked(connection());
  64 }
  65
  66 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  67   if (connection()->version() <= QUIC_VERSION_21) {
  68     return;
  69   }
  70
  71   // If not enough time has passed since the last time we sent an update to the
  72   // client, then return early.
  73   const QuicSentPacketManager& sent_packet_manager =
  74       connection()->sent_packet_manager();
  75   int64 srtt_ms =
  76       sent_packet_manager.GetRttStats()->SmoothedRtt().ToMilliseconds();
  77   int64 now_ms = now.Subtract(last_server_config_update_time_).ToMilliseconds();
  78   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
  79       now_ms < kMinIntervalBetweenServerConfigUpdatesMs) {
  80     return;
  81   }
  82
  83   // If the bandwidth recorder does not have a valid estimate, return early.
  84   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
  85       sent_packet_manager.SustainedBandwidthRecorder();
  86   if (!bandwidth_recorder.HasEstimate()) {
  87     return;
  88   }
  89
  90   // The bandwidth recorder has recorded at least one sustained bandwidth
  91   // estimate. Check that it's substantially different from the last one that
  92   // we sent to the client, and if so, send the new one.
  93   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
  94
  95   int64 bandwidth_delta =
  96       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
  97                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
  98
  99   // Define "substantial" difference as a 50% increase or decrease from the
 100   // last estimate.
 101   bool substantial_difference =
 102       bandwidth_delta >
 103       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 104   if (!substantial_difference) {
 105     return;
 106   }
 107
 108   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 109   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 110            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 111
 112   // Include max bandwidth in the update.
 113   QuicBandwidth max_bandwidth_estimate =
 114       bandwidth_recorder.MaxBandwidthEstimate();
 115   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 116
 117   // Fill the proto before passing it to the crypto stream to send.
 118   CachedNetworkParameters cached_network_params;
 119   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 120       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 121   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 122       max_bandwidth_estimate.ToBytesPerSecond());
 123   cached_network_params.set_max_bandwidth_timestamp_seconds(
 124       max_bandwidth_timestamp);
 125   cached_network_params.set_min_rtt_ms(
 126       sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
 127   cached_network_params.set_previous_connection_state(
 128       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 129           ? CachedNetworkParameters::SLOW_START
 130           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 131   if (!serving_region_.empty()) {
 132     cached_network_params.set_serving_region(serving_region_);
 133   }
 134
 135   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
 136   last_server_config_update_time_ = now;
 137 }
 138
 139 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
 140   if (id % 2 == 0) {
 141     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 142     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 143     return false;
 144   }
 145   if (GetNumOpenStreams() >= get_max_open_streams()) {
 146     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 147              << " Already " << GetNumOpenStreams() << " open.";
 148     connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 149     return false;
 150   }
 151   return true;
 152 }
 153
 154 QuicDataStream* QuicServerSession::CreateIncomingDataStream(
 155     QuicStreamId id) {
 156   if (!ShouldCreateIncomingDataStream(id)) {
 157     return NULL;
 158   }
 159
 160   return new QuicSpdyServerStream(id, this);
 161 }
 162
 163 QuicDataStream* QuicServerSession::CreateOutgoingDataStream() {
 164   DLOG(ERROR) << "Server push not yet supported";
 165   return NULL;
 166 }
 167
 168 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 169   return crypto_stream_.get();
 170 }
 171
 172 }  // namespace tools
 173 }  // namespace net