src/net/quic/quic_server_session.cc

   1 // Copyright 2014 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/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/quic_spdy_server_stream.h"
  12 #include "net/quic/reliable_quic_stream.h"
  13
  14 namespace net {
  15
  16 QuicServerSession::QuicServerSession(const QuicConfig& config,
  17                                      QuicConnection* connection,
  18                                      QuicServerSessionVisitor* visitor,
  19                                      bool is_secure)
  20     : QuicSession(connection, config, is_secure),
  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   if (!FLAGS_enable_quic_fec ||
  42       !config()->HasReceivedConnectionOptions() ||
  43       !ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  44     return;
  45   }
  46   // kFHDR config maps to FEC protection always for headers stream.
  47   // TODO(jri): Add crypto stream in addition to headers for kHDR.
  48   headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
  49 }
  50
  51 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  52                                            bool from_peer) {
  53   QuicSession::OnConnectionClosed(error, from_peer);
  54   // In the unlikely event we get a connection close while doing an asynchronous
  55   // crypto event, make sure we cancel the callback.
  56   if (crypto_stream_.get() != nullptr) {
  57     crypto_stream_->CancelOutstandingCallbacks();
  58   }
  59   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  60 }
  61
  62 void QuicServerSession::OnWriteBlocked() {
  63   QuicSession::OnWriteBlocked();
  64   visitor_->OnWriteBlocked(connection());
  65 }
  66
  67 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  68   if (connection()->version() <= QUIC_VERSION_21) {
  69     return;
  70   }
  71
  72   // If not enough time has passed since the last time we sent an update to the
  73   // client, or not enough packets have been sent, then return early.
  74   const QuicSentPacketManager& sent_packet_manager =
  75       connection()->sent_packet_manager();
  76   int64 srtt_ms =
  77       sent_packet_manager.GetRttStats()->smoothed_rtt().ToMilliseconds();
  78   int64 now_ms = now.Subtract(last_scup_time_).ToMilliseconds();
  79   int64 packets_since_last_scup =
  80       connection()->sequence_number_of_last_sent_packet() -
  81       last_scup_sequence_number_;
  82   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
  83       now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
  84       packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
  85     return;
  86   }
  87
  88   // If the bandwidth recorder does not have a valid estimate, return early.
  89   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
  90       sent_packet_manager.SustainedBandwidthRecorder();
  91   if (!bandwidth_recorder.HasEstimate()) {
  92     return;
  93   }
  94
  95   // The bandwidth recorder has recorded at least one sustained bandwidth
  96   // estimate. Check that it's substantially different from the last one that
  97   // we sent to the client, and if so, send the new one.
  98   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
  99
 100   int64 bandwidth_delta =
 101       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
 102                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
 103
 104   // Define "substantial" difference as a 50% increase or decrease from the
 105   // last estimate.
 106   bool substantial_difference =
 107       bandwidth_delta >
 108       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 109   if (!substantial_difference) {
 110     return;
 111   }
 112
 113   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 114   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 115            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 116
 117   // Include max bandwidth in the update.
 118   QuicBandwidth max_bandwidth_estimate =
 119       bandwidth_recorder.MaxBandwidthEstimate();
 120   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 121
 122   // Fill the proto before passing it to the crypto stream to send.
 123   CachedNetworkParameters cached_network_params;
 124   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 125       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 126   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 127       max_bandwidth_estimate.ToBytesPerSecond());
 128   cached_network_params.set_max_bandwidth_timestamp_seconds(
 129       max_bandwidth_timestamp);
 130   cached_network_params.set_min_rtt_ms(
 131       sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
 132   cached_network_params.set_previous_connection_state(
 133       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 134           ? CachedNetworkParameters::SLOW_START
 135           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 136   cached_network_params.set_timestamp(
 137       connection()->clock()->WallNow().ToUNIXSeconds());
 138   if (!serving_region_.empty()) {
 139     cached_network_params.set_serving_region(serving_region_);
 140   }
 141
 142   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
 143   last_scup_time_ = now;
 144   last_scup_sequence_number_ =
 145       connection()->sequence_number_of_last_sent_packet();
 146 }
 147
 148 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
 149   if (id % 2 == 0) {
 150     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 151     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 152     return false;
 153   }
 154   if (GetNumOpenStreams() >= get_max_open_streams()) {
 155     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 156              << " Already " << GetNumOpenStreams() << " streams open (max "
 157              << get_max_open_streams() << ").";
 158     connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 159     return false;
 160   }
 161   return true;
 162 }
 163
 164 QuicDataStream* QuicServerSession::CreateIncomingDataStream(
 165     QuicStreamId id) {
 166   if (!ShouldCreateIncomingDataStream(id)) {
 167     return nullptr;
 168   }
 169
 170   return new QuicSpdyServerStream(id, this);
 171 }
 172
 173 QuicDataStream* QuicServerSession::CreateOutgoingDataStream() {
 174   DLOG(ERROR) << "Server push not yet supported";
 175   return nullptr;
 176 }
 177
 178 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 179   return crypto_stream_.get();
 180 }
 181
 182 }  // namespace net