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     : QuicSession(connection, config),
  20       visitor_(visitor),
  21       bandwidth_estimate_sent_to_client_(QuicBandwidth::Zero()),
  22       last_server_config_update_time_(QuicTime::Zero()) {}
  23
  24 QuicServerSession::~QuicServerSession() {}
  25
  26 void QuicServerSession::InitializeSession(
  27     const QuicCryptoServerConfig& crypto_config) {
  28   QuicSession::InitializeSession();
  29   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config));
  30 }
  31
  32 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
  33     const QuicCryptoServerConfig& crypto_config) {
  34   return new QuicCryptoServerStream(crypto_config, this);
  35 }
  36
  37 void QuicServerSession::OnConfigNegotiated() {
  38   QuicSession::OnConfigNegotiated();
  39   if (!FLAGS_enable_quic_fec ||
  40       !config()->HasReceivedConnectionOptions() ||
  41       !ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
  42     return;
  43   }
  44   // kFHDR config maps to FEC protection always for headers stream.
  45   // TODO(jri): Add crypto stream in addition to headers for kHDR.
  46   headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
  47 }
  48
  49 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
  50                                            bool from_peer) {
  51   QuicSession::OnConnectionClosed(error, from_peer);
  52   // In the unlikely event we get a connection close while doing an asynchronous
  53   // crypto event, make sure we cancel the callback.
  54   if (crypto_stream_.get() != nullptr) {
  55     crypto_stream_->CancelOutstandingCallbacks();
  56   }
  57   visitor_->OnConnectionClosed(connection()->connection_id(), error);
  58 }
  59
  60 void QuicServerSession::OnWriteBlocked() {
  61   QuicSession::OnWriteBlocked();
  62   visitor_->OnWriteBlocked(connection());
  63 }
  64
  65 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
  66   if (connection()->version() <= QUIC_VERSION_21) {
  67     return;
  68   }
  69
  70   // If not enough time has passed since the last time we sent an update to the
  71   // client, then return early.
  72   const QuicSentPacketManager& sent_packet_manager =
  73       connection()->sent_packet_manager();
  74   int64 srtt_ms =
  75       sent_packet_manager.GetRttStats()->SmoothedRtt().ToMilliseconds();
  76   int64 now_ms = now.Subtract(last_server_config_update_time_).ToMilliseconds();
  77   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
  78       now_ms < kMinIntervalBetweenServerConfigUpdatesMs) {
  79     return;
  80   }
  81
  82   // If the bandwidth recorder does not have a valid estimate, return early.
  83   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
  84       sent_packet_manager.SustainedBandwidthRecorder();
  85   if (!bandwidth_recorder.HasEstimate()) {
  86     return;
  87   }
  88
  89   // The bandwidth recorder has recorded at least one sustained bandwidth
  90   // estimate. Check that it's substantially different from the last one that
  91   // we sent to the client, and if so, send the new one.
  92   QuicBandwidth new_bandwidth_estimate = bandwidth_recorder.BandwidthEstimate();
  93
  94   int64 bandwidth_delta =
  95       std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
  96                bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
  97
  98   // Define "substantial" difference as a 50% increase or decrease from the
  99   // last estimate.
 100   bool substantial_difference =
 101       bandwidth_delta >
 102       0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
 103   if (!substantial_difference) {
 104     return;
 105   }
 106
 107   bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
 108   DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
 109            << bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
 110
 111   // Include max bandwidth in the update.
 112   QuicBandwidth max_bandwidth_estimate =
 113       bandwidth_recorder.MaxBandwidthEstimate();
 114   int32 max_bandwidth_timestamp = bandwidth_recorder.MaxBandwidthTimestamp();
 115
 116   // Fill the proto before passing it to the crypto stream to send.
 117   CachedNetworkParameters cached_network_params;
 118   cached_network_params.set_bandwidth_estimate_bytes_per_second(
 119       bandwidth_estimate_sent_to_client_.ToBytesPerSecond());
 120   cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
 121       max_bandwidth_estimate.ToBytesPerSecond());
 122   cached_network_params.set_max_bandwidth_timestamp_seconds(
 123       max_bandwidth_timestamp);
 124   cached_network_params.set_min_rtt_ms(
 125       sent_packet_manager.GetRttStats()->MinRtt().ToMilliseconds());
 126   cached_network_params.set_previous_connection_state(
 127       bandwidth_recorder.EstimateRecordedDuringSlowStart()
 128           ? CachedNetworkParameters::SLOW_START
 129           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
 130   cached_network_params.set_timestamp(
 131       connection()->clock()->WallNow().ToUNIXSeconds());
 132   if (!serving_region_.empty()) {
 133     cached_network_params.set_serving_region(serving_region_);
 134   }
 135
 136   crypto_stream_->SendServerConfigUpdate(&cached_network_params, false);
 137   last_server_config_update_time_ = now;
 138 }
 139
 140 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
 141   if (id % 2 == 0) {
 142     DVLOG(1) << "Invalid incoming even stream_id:" << id;
 143     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
 144     return false;
 145   }
 146   if (GetNumOpenStreams() >= get_max_open_streams()) {
 147     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
 148              << " Already " << GetNumOpenStreams() << " streams open (max "
 149              << get_max_open_streams() << ").";
 150     connection()->SendConnectionClose(QUIC_TOO_MANY_OPEN_STREAMS);
 151     return false;
 152   }
 153   return true;
 154 }
 155
 156 QuicDataStream* QuicServerSession::CreateIncomingDataStream(
 157     QuicStreamId id) {
 158   if (!ShouldCreateIncomingDataStream(id)) {
 159     return nullptr;
 160   }
 161
 162   return new QuicSpdyServerStream(id, this);
 163 }
 164
 165 QuicDataStream* QuicServerSession::CreateOutgoingDataStream() {
 166   DLOG(ERROR) << "Server push not yet supported";
 167   return nullptr;
 168 }
 169
 170 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
 171   return crypto_stream_.get();
 172 }
 173
 174 }  // namespace net