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// Copyright (c) 2012 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/quic/core/quic_server_session_base.h"
#include "net/quic/core/proto/cached_network_parameters.pb.h"
#include "net/quic/core/quic_connection.h"
#include "net/quic/core/quic_flags.h"
#include "net/quic/core/quic_stream.h"
#include "net/quic/platform/api/quic_bug_tracker.h"
#include "net/quic/platform/api/quic_logging.h"
#include "net/quic/platform/api/quic_string_piece.h"
using std::string;
namespace net {
QuicServerSessionBase::QuicServerSessionBase(
const QuicConfig& config,
QuicConnection* connection,
Visitor* visitor,
QuicCryptoServerStream::Helper* helper,
const QuicCryptoServerConfig* crypto_config,
QuicCompressedCertsCache* compressed_certs_cache)
: QuicSpdySession(connection, visitor, config),
crypto_config_(crypto_config),
compressed_certs_cache_(compressed_certs_cache),
helper_(helper),
bandwidth_resumption_enabled_(false),
bandwidth_estimate_sent_to_client_(QuicBandwidth::Zero()),
last_scup_time_(QuicTime::Zero()),
last_scup_packet_number_(0) {}
QuicServerSessionBase::~QuicServerSessionBase() {}
void QuicServerSessionBase::Initialize() {
crypto_stream_.reset(
CreateQuicCryptoServerStream(crypto_config_, compressed_certs_cache_));
QuicSpdySession::Initialize();
}
void QuicServerSessionBase::OnConfigNegotiated() {
QuicSpdySession::OnConfigNegotiated();
if (!config()->HasReceivedConnectionOptions()) {
return;
}
// Enable bandwidth resumption if peer sent correct connection options.
const bool last_bandwidth_resumption =
ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWRE);
const bool max_bandwidth_resumption =
ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWMX);
bandwidth_resumption_enabled_ =
last_bandwidth_resumption || max_bandwidth_resumption;
if (!FLAGS_quic_reloadable_flag_quic_enable_server_push_by_default ||
connection()->version() < QUIC_VERSION_35) {
set_server_push_enabled(
ContainsQuicTag(config()->ReceivedConnectionOptions(), kSPSH));
}
// If the client has provided a bandwidth estimate from the same serving
// region as this server, then decide whether to use the data for bandwidth
// resumption.
const CachedNetworkParameters* cached_network_params =
crypto_stream_->PreviousCachedNetworkParams();
if (cached_network_params != nullptr &&
cached_network_params->serving_region() == serving_region_) {
// Log the received connection parameters, regardless of how they
// get used for bandwidth resumption.
connection()->OnReceiveConnectionState(*cached_network_params);
if (bandwidth_resumption_enabled_) {
// Only do bandwidth resumption if estimate is recent enough.
const uint64_t seconds_since_estimate =
connection()->clock()->WallNow().ToUNIXSeconds() -
cached_network_params->timestamp();
if (seconds_since_estimate <= kNumSecondsPerHour) {
connection()->ResumeConnectionState(*cached_network_params,
max_bandwidth_resumption);
}
}
}
}
void QuicServerSessionBase::OnConnectionClosed(QuicErrorCode error,
const string& error_details,
ConnectionCloseSource source) {
QuicSession::OnConnectionClosed(error, error_details, source);
// In the unlikely event we get a connection close while doing an asynchronous
// crypto event, make sure we cancel the callback.
if (crypto_stream_.get() != nullptr) {
crypto_stream_->CancelOutstandingCallbacks();
}
}
void QuicServerSessionBase::OnCongestionWindowChange(QuicTime now) {
if (!bandwidth_resumption_enabled_) {
return;
}
// Only send updates when the application has no data to write.
if (HasDataToWrite()) {
return;
}
// If not enough time has passed since the last time we sent an update to the
// client, or not enough packets have been sent, then return early.
const QuicSentPacketManager& sent_packet_manager =
connection()->sent_packet_manager();
int64_t srtt_ms =
sent_packet_manager.GetRttStats()->smoothed_rtt().ToMilliseconds();
int64_t now_ms = (now - last_scup_time_).ToMilliseconds();
int64_t packets_since_last_scup =
connection()->sent_packet_manager().GetLargestSentPacket() -
last_scup_packet_number_;
if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
return;
}
// If the bandwidth recorder does not have a valid estimate, return early.
const QuicSustainedBandwidthRecorder* bandwidth_recorder =
sent_packet_manager.SustainedBandwidthRecorder();
if (bandwidth_recorder == nullptr || !bandwidth_recorder->HasEstimate()) {
return;
}
// The bandwidth recorder has recorded at least one sustained bandwidth
// estimate. Check that it's substantially different from the last one that
// we sent to the client, and if so, send the new one.
QuicBandwidth new_bandwidth_estimate =
bandwidth_recorder->BandwidthEstimate();
int64_t bandwidth_delta =
std::abs(new_bandwidth_estimate.ToBitsPerSecond() -
bandwidth_estimate_sent_to_client_.ToBitsPerSecond());
// Define "substantial" difference as a 50% increase or decrease from the
// last estimate.
bool substantial_difference =
bandwidth_delta >
0.5 * bandwidth_estimate_sent_to_client_.ToBitsPerSecond();
if (!substantial_difference) {
return;
}
bandwidth_estimate_sent_to_client_ = new_bandwidth_estimate;
QUIC_DVLOG(1) << "Server: sending new bandwidth estimate (KBytes/s): "
<< bandwidth_estimate_sent_to_client_.ToKBytesPerSecond();
// Include max bandwidth in the update.
QuicBandwidth max_bandwidth_estimate =
bandwidth_recorder->MaxBandwidthEstimate();
int32_t max_bandwidth_timestamp = bandwidth_recorder->MaxBandwidthTimestamp();
// Fill the proto before passing it to the crypto stream to send.
const int32_t bw_estimate_bytes_per_second =
BandwidthToCachedParameterBytesPerSecond(
bandwidth_estimate_sent_to_client_);
const int32_t max_bw_estimate_bytes_per_second =
BandwidthToCachedParameterBytesPerSecond(max_bandwidth_estimate);
QUIC_BUG_IF(max_bw_estimate_bytes_per_second < 0)
<< max_bw_estimate_bytes_per_second;
QUIC_BUG_IF(bw_estimate_bytes_per_second < 0) << bw_estimate_bytes_per_second;
CachedNetworkParameters cached_network_params;
cached_network_params.set_bandwidth_estimate_bytes_per_second(
bw_estimate_bytes_per_second);
cached_network_params.set_max_bandwidth_estimate_bytes_per_second(
max_bw_estimate_bytes_per_second);
cached_network_params.set_max_bandwidth_timestamp_seconds(
max_bandwidth_timestamp);
cached_network_params.set_min_rtt_ms(
sent_packet_manager.GetRttStats()->min_rtt().ToMilliseconds());
cached_network_params.set_previous_connection_state(
bandwidth_recorder->EstimateRecordedDuringSlowStart()
? CachedNetworkParameters::SLOW_START
: CachedNetworkParameters::CONGESTION_AVOIDANCE);
cached_network_params.set_timestamp(
connection()->clock()->WallNow().ToUNIXSeconds());
if (!serving_region_.empty()) {
cached_network_params.set_serving_region(serving_region_);
}
crypto_stream_->SendServerConfigUpdate(&cached_network_params);
connection()->OnSendConnectionState(cached_network_params);
last_scup_time_ = now;
last_scup_packet_number_ =
connection()->sent_packet_manager().GetLargestSentPacket();
}
bool QuicServerSessionBase::ShouldCreateIncomingDynamicStream(QuicStreamId id) {
if (!connection()->connected()) {
QUIC_BUG << "ShouldCreateIncomingDynamicStream called when disconnected";
return false;
}
if (id % 2 == 0) {
QUIC_DLOG(INFO) << "Invalid incoming even stream_id:" << id;
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Client created even numbered stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
return true;
}
bool QuicServerSessionBase::ShouldCreateOutgoingDynamicStream() {
if (!connection()->connected()) {
QUIC_BUG << "ShouldCreateOutgoingDynamicStream called when disconnected";
return false;
}
if (!crypto_stream_->encryption_established()) {
QUIC_BUG << "Encryption not established so no outgoing stream created.";
return false;
}
if (GetNumOpenOutgoingStreams() >= max_open_outgoing_streams()) {
VLOG(1) << "No more streams should be created. "
<< "Already " << GetNumOpenOutgoingStreams() << " open.";
return false;
}
return true;
}
QuicCryptoServerStreamBase* QuicServerSessionBase::GetCryptoStream() {
return crypto_stream_.get();
}
int32_t QuicServerSessionBase::BandwidthToCachedParameterBytesPerSecond(
const QuicBandwidth& bandwidth) {
int64_t bytes_per_second = bandwidth.ToBytesPerSecond();
return (bytes_per_second > static_cast<int64_t>(INT32_MAX)
? INT32_MAX
: static_cast<int32_t>(bytes_per_second));
}
} // namespace net
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