| // Copyright (c) 2017 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "net/third_party/quiche/src/quic/quartc/quartc_factory.h" |
| |
| #include "net/third_party/quiche/src/quic/core/crypto/quic_random.h" |
| #include "net/third_party/quiche/src/quic/core/quic_utils.h" |
| #include "net/third_party/quiche/src/quic/core/tls_client_handshaker.h" |
| #include "net/third_party/quiche/src/quic/core/tls_server_handshaker.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_ptr_util.h" |
| #include "net/third_party/quiche/src/quic/platform/api/quic_socket_address.h" |
| #include "net/third_party/quiche/src/quic/quartc/quartc_connection_helper.h" |
| #include "net/third_party/quiche/src/quic/quartc/quartc_crypto_helpers.h" |
| #include "net/third_party/quiche/src/quic/quartc/quartc_session.h" |
| |
| namespace quic { |
| |
| std::unique_ptr<QuartcSession> CreateQuartcClientSession( |
| const QuartcSessionConfig& quartc_session_config, |
| const QuicClock* clock, |
| QuicAlarmFactory* alarm_factory, |
| QuicConnectionHelperInterface* connection_helper, |
| const ParsedQuicVersionVector& supported_versions, |
| QuicStringPiece server_crypto_config, |
| QuartcPacketTransport* packet_transport) { |
| DCHECK(packet_transport); |
| |
| // QuartcSession will eventually own both |writer| and |quic_connection|. |
| auto writer = QuicMakeUnique<QuartcPacketWriter>( |
| packet_transport, quartc_session_config.max_packet_size); |
| |
| // While the QuicConfig is not directly used by the connection, creating it |
| // also sets flag values which must be set before creating the connection. |
| QuicConfig quic_config = CreateQuicConfig(quartc_session_config); |
| |
| // |dummy_id| and |dummy_address| are used because Quartc network layer will |
| // not use these two. |
| QuicConnectionId dummy_id = QuicUtils::CreateZeroConnectionId( |
| supported_versions[0].transport_version); |
| QuicSocketAddress dummy_address(QuicIpAddress::Any4(), /*port=*/0); |
| std::unique_ptr<QuicConnection> quic_connection = CreateQuicConnection( |
| dummy_id, dummy_address, connection_helper, alarm_factory, writer.get(), |
| Perspective::IS_CLIENT, supported_versions); |
| |
| return QuicMakeUnique<QuartcClientSession>( |
| std::move(quic_connection), quic_config, supported_versions, clock, |
| std::move(writer), |
| CreateCryptoClientConfig(quartc_session_config.pre_shared_key), |
| server_crypto_config); |
| } |
| |
| void ConfigureGlobalQuicSettings() { |
| // Fixes behavior of StopReading() with level-triggered stream sequencers. |
| SetQuicReloadableFlag(quic_stop_reading_when_level_triggered, true); |
| |
| // Fix b/110259444. |
| SetQuicReloadableFlag(quic_fix_spurious_ack_alarm, true); |
| |
| // Enable version 46 to enable SendMessage API and 'quic bit' per draft 17. |
| SetQuicReloadableFlag(quic_enable_version_46, true); |
| |
| // Enable version 47 to enable variable-length connection ids. |
| SetQuicReloadableFlag(quic_enable_version_47, true); |
| |
| // Fix for inconsistent reporting of crypto handshake. |
| SetQuicReloadableFlag(quic_fix_has_pending_crypto_data, true); |
| |
| // Ensure that we don't drop data because QUIC streams refuse to buffer it. |
| // TODO(b/120099046): Replace this with correct handling of WriteMemSlices(). |
| SetQuicFlag(FLAGS_quic_buffered_data_threshold, |
| std::numeric_limits<int>::max()); |
| |
| // Enable and request QUIC to include receive timestamps in ACK frames. |
| SetQuicReloadableFlag(quic_send_timestamps, true); |
| |
| // Enable ACK_DECIMATION_WITH_REORDERING. It requires ack_decimation to be |
| // false. |
| SetQuicReloadableFlag(quic_enable_ack_decimation, false); |
| |
| // Note: flag settings have no effect for Exoblaze builds since |
| // SetQuicReloadableFlag() gets stubbed out. |
| SetQuicReloadableFlag(quic_bbr_less_probe_rtt, true); // Enable BBR6,7,8. |
| SetQuicReloadableFlag(quic_unified_iw_options, true); // Enable IWXX opts. |
| SetQuicReloadableFlag(quic_bbr_slower_startup3, true); // Enable BBQX opts. |
| SetQuicReloadableFlag(quic_bbr_flexible_app_limited, true); // Enable BBR9. |
| } |
| |
| QuicConfig CreateQuicConfig(const QuartcSessionConfig& quartc_session_config) { |
| // TODO(b/124398962): Figure out a better way to initialize QUIC flags. |
| // Creating a config shouldn't have global side-effects on flags. However, |
| // this has the advantage of ensuring that flag values stay in sync with the |
| // options requested by configs, so simply splitting the config and flag |
| // settings doesn't seem preferable. |
| ConfigureGlobalQuicSettings(); |
| |
| // In exoblaze this may return false. DCHECK to avoid problems caused by |
| // incorrect flags configuration. |
| DCHECK(GetQuicReloadableFlag(quic_enable_version_46)) |
| << "Your build does not support quic reloadable flags and shouldn't " |
| "place Quartc calls"; |
| |
| QuicTagVector copt; |
| copt.push_back(kNSTP); |
| |
| // Enable and request QUIC to include receive timestamps in ACK frames. |
| copt.push_back(kSTMP); |
| |
| // Enable ACK_DECIMATION_WITH_REORDERING. It requires ack_decimation to be |
| // false. |
| copt.push_back(kAKD2); |
| |
| // Use unlimited decimation in order to reduce number of unbundled ACKs. |
| copt.push_back(kAKDU); |
| |
| // Enable time-based loss detection. |
| copt.push_back(kTIME); |
| |
| copt.push_back(kBBR3); // Stay in low-gain until in-flight < BDP. |
| copt.push_back(kBBR5); // 40 RTT ack aggregation. |
| copt.push_back(kBBR6); // Use a 0.75 * BDP cwnd during PROBE_RTT. |
| copt.push_back(kBBR8); // Skip PROBE_RTT if app-limited. |
| copt.push_back(kBBR9); // Ignore app-limited if enough data is in flight. |
| copt.push_back(kBBQ1); // 2.773 pacing gain in STARTUP. |
| copt.push_back(kBBQ2); // 2.0 CWND gain in STARTUP. |
| copt.push_back(k1RTT); // Exit STARTUP after 1 RTT with no gains. |
| copt.push_back(kIW10); // 10-packet (14600 byte) initial cwnd. |
| |
| if (!quartc_session_config.enable_tail_loss_probe) { |
| copt.push_back(kNTLP); |
| } |
| |
| // TODO(b/112192153): Test and possible enable slower startup when pipe |
| // filling is ready to use. Slower startup is kBBRS. |
| |
| QuicConfig quic_config; |
| |
| // Use the limits for the session & stream flow control. The default 16KB |
| // limit leads to significantly undersending (not reaching BWE on the outgoing |
| // bitrate) due to blocked frames, and it leads to high latency (and one-way |
| // delay). Setting it to its limits is not going to cause issues (our streams |
| // are small generally, and if we were to buffer 24MB it wouldn't be the end |
| // of the world). We can consider setting different limits in future (e.g. 1MB |
| // stream, 1.5MB session). It's worth noting that on 1mbps bitrate, limit of |
| // 24MB can capture approx 4 minutes of the call, and the default increase in |
| // size of the window (half of the window size) is approximately 2 minutes of |
| // the call. |
| quic_config.SetInitialSessionFlowControlWindowToSend( |
| kSessionReceiveWindowLimit); |
| quic_config.SetInitialStreamFlowControlWindowToSend( |
| kStreamReceiveWindowLimit); |
| quic_config.SetConnectionOptionsToSend(copt); |
| quic_config.SetClientConnectionOptions(copt); |
| if (quartc_session_config.max_time_before_crypto_handshake > |
| QuicTime::Delta::Zero()) { |
| quic_config.set_max_time_before_crypto_handshake( |
| quartc_session_config.max_time_before_crypto_handshake); |
| } |
| if (quartc_session_config.max_idle_time_before_crypto_handshake > |
| QuicTime::Delta::Zero()) { |
| quic_config.set_max_idle_time_before_crypto_handshake( |
| quartc_session_config.max_idle_time_before_crypto_handshake); |
| } |
| if (quartc_session_config.idle_network_timeout > QuicTime::Delta::Zero()) { |
| quic_config.SetIdleNetworkTimeout( |
| quartc_session_config.idle_network_timeout, |
| quartc_session_config.idle_network_timeout); |
| } |
| |
| // The ICE transport provides a unique 5-tuple for each connection. Save |
| // overhead by omitting the connection id. |
| quic_config.SetBytesForConnectionIdToSend(0); |
| |
| // Allow up to 1000 incoming streams at once. Quartc streams typically contain |
| // one audio or video frame and close immediately. However, when a video frame |
| // becomes larger than one packet, there is some delay between the start and |
| // end of each stream. The default maximum of 100 only leaves about 1 second |
| // of headroom (Quartc sends ~30 video frames per second) before QUIC starts |
| // to refuse incoming streams. Back-pressure should clear backlogs of |
| // incomplete streams, but targets 1 second for recovery. Increasing the |
| // number of open streams gives sufficient headroom to recover before QUIC |
| // refuses new streams. |
| quic_config.SetMaxIncomingBidirectionalStreamsToSend(1000); |
| |
| return quic_config; |
| } |
| |
| std::unique_ptr<QuicConnection> CreateQuicConnection( |
| QuicConnectionId connection_id, |
| const QuicSocketAddress& peer_address, |
| QuicConnectionHelperInterface* connection_helper, |
| QuicAlarmFactory* alarm_factory, |
| QuicPacketWriter* packet_writer, |
| Perspective perspective, |
| ParsedQuicVersionVector supported_versions) { |
| auto quic_connection = QuicMakeUnique<QuicConnection>( |
| connection_id, peer_address, connection_helper, alarm_factory, |
| packet_writer, |
| /*owns_writer=*/false, perspective, supported_versions); |
| quic_connection->SetMaxPacketLength( |
| packet_writer->GetMaxPacketSize(peer_address)); |
| |
| QuicSentPacketManager& sent_packet_manager = |
| quic_connection->sent_packet_manager(); |
| |
| // Default delayed ack time is 25ms. |
| // If data packets are sent less often (e.g. because p-time was modified), |
| // we would force acks to be sent every 25ms regardless, increasing |
| // overhead. Since generally we guarantee a packet every 20ms, changing |
| // this value should have miniscule effect on quality on good connections, |
| // but on poor connections, changing this number significantly reduced the |
| // number of ack-only packets. |
| // The p-time can go up to as high as 120ms, and when it does, it's |
| // when the low overhead is the most important thing. Ideally it should be |
| // above 120ms, but it cannot be higher than 0.5*RTO, which equals to 100ms. |
| sent_packet_manager.set_delayed_ack_time( |
| QuicTime::Delta::FromMilliseconds(100)); |
| |
| quic_connection->set_fill_up_link_during_probing(true); |
| |
| // We start ack decimation after 15 packets. Typically, we would see |
| // 1-2 crypto handshake packets, one media packet, and 10 probing packets. |
| // We want to get acks for the probing packets as soon as possible, |
| // but we can start using ack decimation right after first probing completes. |
| // The default was to not start ack decimation for the first 100 packets. |
| quic_connection->set_min_received_before_ack_decimation(15); |
| |
| return quic_connection; |
| } |
| |
| } // namespace quic |