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quiche / quiche.git / 56835aa2c2e3645e0eec85bff07f9d58e3bace63 / . / quic / core / quic_connection.cc
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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/third_party/quiche/src/quic/core/quic_connection.h"
#include <string.h>
#include <sys/types.h>
#include <algorithm>
#include <iterator>
#include <limits>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include "net/third_party/quiche/src/quic/core/crypto/crypto_protocol.h"
#include "net/third_party/quiche/src/quic/core/crypto/crypto_utils.h"
#include "net/third_party/quiche/src/quic/core/crypto/quic_decrypter.h"
#include "net/third_party/quiche/src/quic/core/crypto/quic_encrypter.h"
#include "net/third_party/quiche/src/quic/core/proto/cached_network_parameters_proto.h"
#include "net/third_party/quiche/src/quic/core/quic_bandwidth.h"
#include "net/third_party/quiche/src/quic/core/quic_config.h"
#include "net/third_party/quiche/src/quic/core/quic_connection_id.h"
#include "net/third_party/quiche/src/quic/core/quic_error_codes.h"
#include "net/third_party/quiche/src/quic/core/quic_packet_generator.h"
#include "net/third_party/quiche/src/quic/core/quic_pending_retransmission.h"
#include "net/third_party/quiche/src/quic/core/quic_types.h"
#include "net/third_party/quiche/src/quic/core/quic_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_client_stats.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_error_code_wrappers.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_exported_stats.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_flag_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_flags.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_map_util.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_str_cat.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_string_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_text_utils.h"
namespace quic {
class QuicDecrypter;
class QuicEncrypter;
namespace {
// Maximum number of consecutive sent nonretransmittable packets.
const QuicPacketCount kMaxConsecutiveNonRetransmittablePackets = 19;
// The minimum release time into future in ms.
const int kMinReleaseTimeIntoFutureMs = 1;
// An alarm that is scheduled to send an ack if a timeout occurs.
class AckAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit AckAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
AckAlarmDelegate(const AckAlarmDelegate&) = delete;
AckAlarmDelegate& operator=(const AckAlarmDelegate&) = delete;
void OnAlarm() override {
DCHECK(connection_->ack_frame_updated());
QuicConnection::ScopedPacketFlusher flusher(connection_);
if (connection_->SupportsMultiplePacketNumberSpaces()) {
connection_->SendAllPendingAcks();
} else {
DCHECK(!connection_->GetUpdatedAckFrame().ack_frame->packets.Empty());
connection_->SendAck();
}
}
private:
QuicConnection* connection_;
};
// This alarm will be scheduled any time a data-bearing packet is sent out.
// When the alarm goes off, the connection checks to see if the oldest packets
// have been acked, and retransmit them if they have not.
class RetransmissionAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit RetransmissionAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
RetransmissionAlarmDelegate(const RetransmissionAlarmDelegate&) = delete;
RetransmissionAlarmDelegate& operator=(const RetransmissionAlarmDelegate&) =
delete;
void OnAlarm() override { connection_->OnRetransmissionTimeout(); }
private:
QuicConnection* connection_;
};
// An alarm that is scheduled when the SentPacketManager requires a delay
// before sending packets and fires when the packet may be sent.
class SendAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit SendAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
SendAlarmDelegate(const SendAlarmDelegate&) = delete;
SendAlarmDelegate& operator=(const SendAlarmDelegate&) = delete;
void OnAlarm() override { connection_->WriteAndBundleAcksIfNotBlocked(); }
private:
QuicConnection* connection_;
};
class PathDegradingAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit PathDegradingAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
PathDegradingAlarmDelegate(const PathDegradingAlarmDelegate&) = delete;
PathDegradingAlarmDelegate& operator=(const PathDegradingAlarmDelegate&) =
delete;
void OnAlarm() override { connection_->OnPathDegradingTimeout(); }
private:
QuicConnection* connection_;
};
class TimeoutAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit TimeoutAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
TimeoutAlarmDelegate(const TimeoutAlarmDelegate&) = delete;
TimeoutAlarmDelegate& operator=(const TimeoutAlarmDelegate&) = delete;
void OnAlarm() override { connection_->CheckForTimeout(); }
private:
QuicConnection* connection_;
};
class PingAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit PingAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
PingAlarmDelegate(const PingAlarmDelegate&) = delete;
PingAlarmDelegate& operator=(const PingAlarmDelegate&) = delete;
void OnAlarm() override { connection_->OnPingTimeout(); }
private:
QuicConnection* connection_;
};
class MtuDiscoveryAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit MtuDiscoveryAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
MtuDiscoveryAlarmDelegate(const MtuDiscoveryAlarmDelegate&) = delete;
MtuDiscoveryAlarmDelegate& operator=(const MtuDiscoveryAlarmDelegate&) =
delete;
void OnAlarm() override { connection_->DiscoverMtu(); }
private:
QuicConnection* connection_;
};
class ProcessUndecryptablePacketsAlarmDelegate : public QuicAlarm::Delegate {
public:
explicit ProcessUndecryptablePacketsAlarmDelegate(QuicConnection* connection)
: connection_(connection) {}
ProcessUndecryptablePacketsAlarmDelegate(
const ProcessUndecryptablePacketsAlarmDelegate&) = delete;
ProcessUndecryptablePacketsAlarmDelegate& operator=(
const ProcessUndecryptablePacketsAlarmDelegate&) = delete;
void OnAlarm() override {
QuicConnection::ScopedPacketFlusher flusher(connection_);
connection_->MaybeProcessUndecryptablePackets();
}
private:
QuicConnection* connection_;
};
// Whether this incoming packet is allowed to replace our connection ID.
bool PacketCanReplaceConnectionId(const QuicPacketHeader& header,
Perspective perspective) {
return perspective == Perspective::IS_CLIENT &&
header.form == IETF_QUIC_LONG_HEADER_PACKET &&
QuicUtils::VariableLengthConnectionIdAllowedForVersion(
header.version.transport_version) &&
(header.long_packet_type == INITIAL ||
header.long_packet_type == RETRY);
}
CongestionControlType GetDefaultCongestionControlType() {
if (GetQuicReloadableFlag(quic_default_to_bbr_v2)) {
return kBBRv2;
}
if (GetQuicReloadableFlag(quic_default_to_bbr)) {
return kBBR;
}
return kCubicBytes;
}
} // namespace
#define ENDPOINT \
(perspective_ == Perspective::IS_SERVER ? "Server: " : "Client: ")
QuicConnection::QuicConnection(
QuicConnectionId server_connection_id,
QuicSocketAddress initial_peer_address,
QuicConnectionHelperInterface* helper,
QuicAlarmFactory* alarm_factory,
QuicPacketWriter* writer,
bool owns_writer,
Perspective perspective,
const ParsedQuicVersionVector& supported_versions)
: framer_(supported_versions,
helper->GetClock()->ApproximateNow(),
perspective,
server_connection_id.length()),
current_packet_content_(NO_FRAMES_RECEIVED),
is_current_packet_connectivity_probing_(false),
current_effective_peer_migration_type_(NO_CHANGE),
helper_(helper),
alarm_factory_(alarm_factory),
per_packet_options_(nullptr),
writer_(writer),
owns_writer_(owns_writer),
encryption_level_(ENCRYPTION_INITIAL),
clock_(helper->GetClock()),
random_generator_(helper->GetRandomGenerator()),
server_connection_id_(server_connection_id),
client_connection_id_(EmptyQuicConnectionId()),
client_connection_id_is_set_(false),
peer_address_(initial_peer_address),
direct_peer_address_(initial_peer_address),
active_effective_peer_migration_type_(NO_CHANGE),
last_packet_decrypted_(false),
last_size_(0),
current_packet_data_(nullptr),
last_decrypted_packet_level_(ENCRYPTION_INITIAL),
should_last_packet_instigate_acks_(false),
max_undecryptable_packets_(0),
max_tracked_packets_(GetQuicFlag(FLAGS_quic_max_tracked_packet_count)),
pending_version_negotiation_packet_(false),
send_ietf_version_negotiation_packet_(false),
send_version_negotiation_packet_with_prefixed_lengths_(false),
idle_timeout_connection_close_behavior_(
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET),
close_connection_after_five_rtos_(false),
uber_received_packet_manager_(&stats_),
stop_waiting_count_(0),
pending_retransmission_alarm_(false),
defer_send_in_response_to_packets_(false),
ping_timeout_(QuicTime::Delta::FromSeconds(kPingTimeoutSecs)),
initial_retransmittable_on_wire_timeout_(QuicTime::Delta::Infinite()),
consecutive_retransmittable_on_wire_ping_count_(0),
arena_(),
ack_alarm_(alarm_factory_->CreateAlarm(arena_.New<AckAlarmDelegate>(this),
&arena_)),
retransmission_alarm_(alarm_factory_->CreateAlarm(
arena_.New<RetransmissionAlarmDelegate>(this),
&arena_)),
send_alarm_(
alarm_factory_->CreateAlarm(arena_.New<SendAlarmDelegate>(this),
&arena_)),
timeout_alarm_(
alarm_factory_->CreateAlarm(arena_.New<TimeoutAlarmDelegate>(this),
&arena_)),
ping_alarm_(
alarm_factory_->CreateAlarm(arena_.New<PingAlarmDelegate>(this),
&arena_)),
mtu_discovery_alarm_(alarm_factory_->CreateAlarm(
arena_.New<MtuDiscoveryAlarmDelegate>(this),
&arena_)),
path_degrading_alarm_(alarm_factory_->CreateAlarm(
arena_.New<PathDegradingAlarmDelegate>(this),
&arena_)),
process_undecryptable_packets_alarm_(alarm_factory_->CreateAlarm(
arena_.New<ProcessUndecryptablePacketsAlarmDelegate>(this),
&arena_)),
visitor_(nullptr),
debug_visitor_(nullptr),
packet_generator_(server_connection_id_,
&framer_,
random_generator_,
this),
idle_network_timeout_(QuicTime::Delta::Infinite()),
handshake_timeout_(QuicTime::Delta::Infinite()),
time_of_first_packet_sent_after_receiving_(QuicTime::Zero()),
time_of_last_received_packet_(clock_->ApproximateNow()),
sent_packet_manager_(perspective,
clock_,
random_generator_,
&stats_,
GetDefaultCongestionControlType(),
kNack),
version_negotiated_(false),
perspective_(perspective),
connected_(true),
can_truncate_connection_ids_(perspective == Perspective::IS_SERVER),
mtu_discovery_target_(0),
mtu_probe_count_(0),
packets_between_mtu_probes_(kPacketsBetweenMtuProbesBase),
next_mtu_probe_at_(kPacketsBetweenMtuProbesBase),
largest_received_packet_size_(0),
write_error_occurred_(false),
no_stop_waiting_frames_(
VersionHasIetfInvariantHeader(transport_version())),
consecutive_num_packets_with_no_retransmittable_frames_(0),
max_consecutive_num_packets_with_no_retransmittable_frames_(
kMaxConsecutiveNonRetransmittablePackets),
fill_up_link_during_probing_(false),
probing_retransmission_pending_(false),
stateless_reset_token_received_(false),
received_stateless_reset_token_(0),
last_control_frame_id_(kInvalidControlFrameId),
is_path_degrading_(false),
processing_ack_frame_(false),
supports_release_time_(false),
release_time_into_future_(QuicTime::Delta::Zero()),
retry_has_been_parsed_(false),
max_consecutive_ptos_(0),
bytes_received_before_address_validation_(0),
bytes_sent_before_address_validation_(0),
address_validated_(false),
skip_packet_number_for_pto_(false),
treat_queued_packets_as_sent_(
GetQuicReloadableFlag(quic_treat_queued_packets_as_sent)),
mtu_discovery_v2_(GetQuicReloadableFlag(quic_mtu_discovery_v2)) {
QUIC_DLOG(INFO) << ENDPOINT << "Created connection with server connection ID "
<< server_connection_id
<< " and version: " << ParsedQuicVersionToString(version());
QUIC_BUG_IF(!QuicUtils::IsConnectionIdValidForVersion(server_connection_id,
transport_version()))
<< "QuicConnection: attempted to use server connection ID "
<< server_connection_id << " which is invalid with version "
<< QuicVersionToString(transport_version());
framer_.set_visitor(this);
stats_.connection_creation_time = clock_->ApproximateNow();
// TODO(ianswett): Supply the NetworkChangeVisitor as a constructor argument
// and make it required non-null, because it's always used.
sent_packet_manager_.SetNetworkChangeVisitor(this);
if (GetQuicRestartFlag(quic_offload_pacing_to_usps2)) {
sent_packet_manager_.SetPacingAlarmGranularity(QuicTime::Delta::Zero());
release_time_into_future_ =
QuicTime::Delta::FromMilliseconds(kMinReleaseTimeIntoFutureMs);
}
// Allow the packet writer to potentially reduce the packet size to a value
// even smaller than kDefaultMaxPacketSize.
SetMaxPacketLength(perspective_ == Perspective::IS_SERVER
? kDefaultServerMaxPacketSize
: kDefaultMaxPacketSize);
uber_received_packet_manager_.set_max_ack_ranges(255);
MaybeEnableSessionDecidesWhatToWrite();
MaybeEnableMultiplePacketNumberSpacesSupport();
DCHECK(perspective_ == Perspective::IS_CLIENT ||
supported_versions.size() == 1);
InstallInitialCrypters(server_connection_id_);
}
void QuicConnection::InstallInitialCrypters(QuicConnectionId connection_id) {
if (!framer_.framer_doesnt_create_initial_encrypter() &&
!version().UsesInitialObfuscators() &&
version().handshake_protocol != PROTOCOL_TLS1_3) {
// Initial crypters are currently only supported with TLS.
return;
}
CrypterPair crypters;
CryptoUtils::CreateInitialObfuscators(perspective_, version(), connection_id,
&crypters);
SetEncrypter(ENCRYPTION_INITIAL, std::move(crypters.encrypter));
if (version().KnowsWhichDecrypterToUse()) {
InstallDecrypter(ENCRYPTION_INITIAL, std::move(crypters.decrypter));
} else {
SetDecrypter(ENCRYPTION_INITIAL, std::move(crypters.decrypter));
}
}
QuicConnection::~QuicConnection() {
if (owns_writer_) {
delete writer_;
}
ClearQueuedPackets();
}
void QuicConnection::ClearQueuedPackets() {
for (auto it = queued_packets_.begin(); it != queued_packets_.end(); ++it) {
// Delete the buffer before calling ClearSerializedPacket, which sets
// encrypted_buffer to nullptr.
DCHECK(!treat_queued_packets_as_sent_);
delete[] it->encrypted_buffer;
ClearSerializedPacket(&(*it));
}
queued_packets_.clear();
buffered_packets_.clear();
}
void QuicConnection::SetFromConfig(const QuicConfig& config) {
if (config.negotiated()) {
// Handshake complete, set handshake timeout to Infinite.
SetNetworkTimeouts(QuicTime::Delta::Infinite(),
config.IdleNetworkTimeout());
if (config.SilentClose()) {
idle_timeout_connection_close_behavior_ =
ConnectionCloseBehavior::SILENT_CLOSE;
}
} else {
SetNetworkTimeouts(config.max_time_before_crypto_handshake(),
config.max_idle_time_before_crypto_handshake());
}
sent_packet_manager_.SetFromConfig(config);
if (config.HasReceivedBytesForConnectionId() &&
can_truncate_connection_ids_) {
packet_generator_.SetServerConnectionIdLength(
config.ReceivedBytesForConnectionId());
}
max_undecryptable_packets_ = config.max_undecryptable_packets();
if (config.HasClientSentConnectionOption(kMTUH, perspective_)) {
SetMtuDiscoveryTarget(kMtuDiscoveryTargetPacketSizeHigh);
}
if (config.HasClientSentConnectionOption(kMTUL, perspective_)) {
SetMtuDiscoveryTarget(kMtuDiscoveryTargetPacketSizeLow);
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSetFromConfig(config);
}
uber_received_packet_manager_.SetFromConfig(config, perspective_);
if (config.HasClientSentConnectionOption(k5RTO, perspective_)) {
close_connection_after_five_rtos_ = true;
}
if (sent_packet_manager_.pto_enabled()) {
if (config.HasClientSentConnectionOption(k6PTO, perspective_)) {
max_consecutive_ptos_ = 5;
QUIC_CODE_COUNT(quic_close_connection_6pto);
}
if (config.HasClientSentConnectionOption(k7PTO, perspective_)) {
max_consecutive_ptos_ = 6;
QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 3, 4);
}
if (config.HasClientSentConnectionOption(k8PTO, perspective_)) {
max_consecutive_ptos_ = 7;
QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 4, 4);
}
if (GetQuicReloadableFlag(quic_skip_packet_number_for_pto) &&
config.HasClientSentConnectionOption(kPTOS, perspective_)) {
QUIC_RELOADABLE_FLAG_COUNT(quic_skip_packet_number_for_pto);
skip_packet_number_for_pto_ = true;
}
}
if (config.HasClientSentConnectionOption(kNSTP, perspective_)) {
no_stop_waiting_frames_ = true;
}
if (config.HasReceivedStatelessResetToken()) {
stateless_reset_token_received_ = true;
received_stateless_reset_token_ = config.ReceivedStatelessResetToken();
}
if (config.HasReceivedAckDelayExponent()) {
framer_.set_peer_ack_delay_exponent(config.ReceivedAckDelayExponent());
}
if (GetQuicReloadableFlag(quic_send_timestamps) &&
config.HasClientSentConnectionOption(kSTMP, perspective_)) {
QUIC_RELOADABLE_FLAG_COUNT(quic_send_timestamps);
framer_.set_process_timestamps(true);
uber_received_packet_manager_.set_save_timestamps(true);
}
supports_release_time_ =
writer_ != nullptr && writer_->SupportsReleaseTime() &&
!config.HasClientSentConnectionOption(kNPCO, perspective_);
if (supports_release_time_) {
UpdateReleaseTimeIntoFuture();
}
}
void QuicConnection::OnSendConnectionState(
const CachedNetworkParameters& cached_network_params) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSendConnectionState(cached_network_params);
}
}
void QuicConnection::OnReceiveConnectionState(
const CachedNetworkParameters& cached_network_params) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnReceiveConnectionState(cached_network_params);
}
}
void QuicConnection::ResumeConnectionState(
const CachedNetworkParameters& cached_network_params,
bool max_bandwidth_resumption) {
sent_packet_manager_.ResumeConnectionState(cached_network_params,
max_bandwidth_resumption);
}
void QuicConnection::SetMaxPacingRate(QuicBandwidth max_pacing_rate) {
sent_packet_manager_.SetMaxPacingRate(max_pacing_rate);
}
void QuicConnection::AdjustNetworkParameters(QuicBandwidth bandwidth,
QuicTime::Delta rtt,
bool allow_cwnd_to_decrease) {
sent_packet_manager_.AdjustNetworkParameters(bandwidth, rtt,
allow_cwnd_to_decrease);
}
QuicBandwidth QuicConnection::MaxPacingRate() const {
return sent_packet_manager_.MaxPacingRate();
}
bool QuicConnection::SelectMutualVersion(
const ParsedQuicVersionVector& available_versions) {
// Try to find the highest mutual version by iterating over supported
// versions, starting with the highest, and breaking out of the loop once we
// find a matching version in the provided available_versions vector.
const ParsedQuicVersionVector& supported_versions =
framer_.supported_versions();
for (size_t i = 0; i < supported_versions.size(); ++i) {
const ParsedQuicVersion& version = supported_versions[i];
if (QuicContainsValue(available_versions, version)) {
framer_.set_version(version);
return true;
}
}
return false;
}
void QuicConnection::OnError(QuicFramer* framer) {
// Packets that we can not or have not decrypted are dropped.
// TODO(rch): add stats to measure this.
if (!connected_ || last_packet_decrypted_ == false) {
return;
}
CloseConnection(framer->error(), framer->detailed_error(),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
void QuicConnection::OnPacket() {
last_packet_decrypted_ = false;
}
void QuicConnection::OnPublicResetPacket(const QuicPublicResetPacket& packet) {
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here. (Check for a bug regression.)
DCHECK_EQ(server_connection_id_, packet.connection_id);
DCHECK_EQ(perspective_, Perspective::IS_CLIENT);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPublicResetPacket(packet);
}
std::string error_details = "Received public reset.";
if (perspective_ == Perspective::IS_CLIENT && !packet.endpoint_id.empty()) {
QuicStrAppend(&error_details, " From ", packet.endpoint_id, ".");
}
QUIC_DLOG(INFO) << ENDPOINT << error_details;
QUIC_CODE_COUNT(quic_tear_down_local_connection_on_public_reset);
TearDownLocalConnectionState(QUIC_PUBLIC_RESET, error_details,
ConnectionCloseSource::FROM_PEER);
}
bool QuicConnection::OnProtocolVersionMismatch(
ParsedQuicVersion received_version) {
QUIC_DLOG(INFO) << ENDPOINT << "Received packet with mismatched version "
<< ParsedQuicVersionToString(received_version);
if (perspective_ == Perspective::IS_CLIENT) {
const std::string error_details = "Protocol version mismatch.";
QUIC_BUG << ENDPOINT << error_details;
CloseConnection(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseBehavior::SILENT_CLOSE);
}
// Server drops old packets that were sent by the client before the version
// was negotiated.
return false;
}
// Handles version negotiation for client connection.
void QuicConnection::OnVersionNegotiationPacket(
const QuicVersionNegotiationPacket& packet) {
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here. (Check for a bug regression.)
DCHECK_EQ(server_connection_id_, packet.connection_id);
if (perspective_ == Perspective::IS_SERVER) {
const std::string error_details =
"Server received version negotiation packet.";
QUIC_BUG << error_details;
QUIC_CODE_COUNT(quic_tear_down_local_connection_on_version_negotiation);
CloseConnection(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseBehavior::SILENT_CLOSE);
return;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnVersionNegotiationPacket(packet);
}
if (version_negotiated_) {
// Possibly a duplicate version negotiation packet.
return;
}
if (QuicContainsValue(packet.versions, version())) {
const std::string error_details = QuicStrCat(
"Server already supports client's version ",
ParsedQuicVersionToString(version()),
" and should have accepted the connection instead of sending {",
ParsedQuicVersionVectorToString(packet.versions), "}.");
QUIC_DLOG(WARNING) << error_details;
CloseConnection(QUIC_INVALID_VERSION_NEGOTIATION_PACKET, error_details,
ConnectionCloseBehavior::SILENT_CLOSE);
return;
}
server_supported_versions_ = packet.versions;
CloseConnection(
QUIC_INVALID_VERSION,
QuicStrCat(
"Client may support one of the versions in the server's list, but "
"it's going to close the connection anyway. Supported versions: {",
ParsedQuicVersionVectorToString(framer_.supported_versions()),
"}, peer supported versions: {",
ParsedQuicVersionVectorToString(packet.versions), "}"),
ConnectionCloseBehavior::SILENT_CLOSE);
}
// Handles retry for client connection.
void QuicConnection::OnRetryPacket(QuicConnectionId original_connection_id,
QuicConnectionId new_connection_id,
QuicStringPiece retry_token) {
DCHECK_EQ(Perspective::IS_CLIENT, perspective_);
if (original_connection_id != server_connection_id_) {
QUIC_DLOG(ERROR) << "Ignoring RETRY with original connection ID "
<< original_connection_id << " not matching expected "
<< server_connection_id_ << " token "
<< QuicTextUtils::HexEncode(retry_token);
return;
}
if (retry_has_been_parsed_) {
QUIC_DLOG(ERROR) << "Ignoring non-first RETRY with token "
<< QuicTextUtils::HexEncode(retry_token);
return;
}
retry_has_been_parsed_ = true;
stats_.retry_packet_processed = true;
QUIC_DLOG(INFO) << "Received RETRY, replacing connection ID "
<< server_connection_id_ << " with " << new_connection_id
<< ", received token "
<< QuicTextUtils::HexEncode(retry_token);
server_connection_id_ = new_connection_id;
packet_generator_.SetServerConnectionId(server_connection_id_);
packet_generator_.SetRetryToken(retry_token);
// Reinstall initial crypters because the connection ID changed.
InstallInitialCrypters(server_connection_id_);
}
bool QuicConnection::HasIncomingConnectionId(QuicConnectionId connection_id) {
for (QuicConnectionId const& incoming_connection_id :
incoming_connection_ids_) {
if (incoming_connection_id == connection_id) {
return true;
}
}
return false;
}
void QuicConnection::AddIncomingConnectionId(QuicConnectionId connection_id) {
if (HasIncomingConnectionId(connection_id)) {
return;
}
incoming_connection_ids_.push_back(connection_id);
}
bool QuicConnection::OnUnauthenticatedPublicHeader(
const QuicPacketHeader& header) {
QuicConnectionId server_connection_id =
GetServerConnectionIdAsRecipient(header, perspective_);
if (server_connection_id != server_connection_id_ &&
!HasIncomingConnectionId(server_connection_id)) {
if (PacketCanReplaceConnectionId(header, perspective_)) {
QUIC_DLOG(INFO) << ENDPOINT << "Accepting packet with new connection ID "
<< server_connection_id << " instead of "
<< server_connection_id_;
return true;
}
++stats_.packets_dropped;
QUIC_DLOG(INFO) << ENDPOINT
<< "Ignoring packet from unexpected server connection ID "
<< server_connection_id << " instead of "
<< server_connection_id_;
if (debug_visitor_ != nullptr) {
debug_visitor_->OnIncorrectConnectionId(server_connection_id);
}
// If this is a server, the dispatcher routes each packet to the
// QuicConnection responsible for the packet's connection ID. So if control
// arrives here and this is a server, the dispatcher must be malfunctioning.
DCHECK_NE(Perspective::IS_SERVER, perspective_);
return false;
}
if (!version().SupportsClientConnectionIds()) {
return true;
}
QuicConnectionId client_connection_id =
GetClientConnectionIdAsRecipient(header, perspective_);
if (client_connection_id == client_connection_id_) {
return true;
}
if (!client_connection_id_is_set_ && perspective_ == Perspective::IS_SERVER) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Setting client connection ID from first packet to "
<< client_connection_id;
set_client_connection_id(client_connection_id);
return true;
}
++stats_.packets_dropped;
QUIC_DLOG(INFO) << ENDPOINT
<< "Ignoring packet from unexpected client connection ID "
<< client_connection_id << " instead of "
<< client_connection_id_;
return false;
}
bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnUnauthenticatedHeader(header);
}
// Check that any public reset packet with a different connection ID that was
// routed to this QuicConnection has been redirected before control reaches
// here.
DCHECK(GetServerConnectionIdAsRecipient(header, perspective_) ==
server_connection_id_ ||
HasIncomingConnectionId(
GetServerConnectionIdAsRecipient(header, perspective_)) ||
PacketCanReplaceConnectionId(header, perspective_));
if (packet_generator_.HasPendingFrames()) {
// Incoming packets may change a queued ACK frame.
const std::string error_details =
"Pending frames must be serialized before incoming packets are "
"processed.";
QUIC_BUG << error_details << ", received header: " << header;
CloseConnection(QUIC_INTERNAL_ERROR, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (!version_negotiated_ && perspective_ == Perspective::IS_SERVER) {
if (!header.version_flag) {
// Packets should have the version flag till version negotiation is
// done.
std::string error_details =
QuicStrCat(ENDPOINT, "Packet ", header.packet_number.ToUint64(),
" without version flag before version negotiated.");
QUIC_DLOG(WARNING) << error_details;
CloseConnection(QUIC_INVALID_VERSION, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
} else {
DCHECK_EQ(header.version, version());
version_negotiated_ = true;
framer_.InferPacketHeaderTypeFromVersion();
visitor_->OnSuccessfulVersionNegotiation(version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(version());
}
}
DCHECK(version_negotiated_);
}
return true;
}
void QuicConnection::OnDecryptedPacket(EncryptionLevel level) {
last_decrypted_packet_level_ = level;
last_packet_decrypted_ = true;
if (EnforceAntiAmplificationLimit() &&
last_decrypted_packet_level_ >= ENCRYPTION_HANDSHAKE) {
// Address is validated by successfully processing a HANDSHAKE packet.
address_validated_ = true;
}
// Once the server receives a forward secure packet, the handshake is
// confirmed.
if (level == ENCRYPTION_FORWARD_SECURE &&
perspective_ == Perspective::IS_SERVER) {
OnHandshakeComplete();
}
}
QuicSocketAddress QuicConnection::GetEffectivePeerAddressFromCurrentPacket()
const {
// By default, the connection is not proxied, and the effective peer address
// is the packet's source address, i.e. the direct peer address.
return last_packet_source_address_;
}
bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketHeader(header);
}
// Will be decremented below if we fall through to return true.
++stats_.packets_dropped;
if (!ProcessValidatedPacket(header)) {
return false;
}
// Initialize the current packet content state.
current_packet_content_ = NO_FRAMES_RECEIVED;
is_current_packet_connectivity_probing_ = false;
current_effective_peer_migration_type_ = NO_CHANGE;
if (perspective_ == Perspective::IS_CLIENT) {
if (!GetLargestReceivedPacket().IsInitialized() ||
header.packet_number > GetLargestReceivedPacket()) {
// Update peer_address_ and effective_peer_address_ immediately for
// client connections.
// TODO(fayang): only change peer addresses in application data packet
// number space.
direct_peer_address_ = last_packet_source_address_;
effective_peer_address_ = GetEffectivePeerAddressFromCurrentPacket();
}
} else {
// At server, remember the address change type of effective_peer_address
// in current_effective_peer_migration_type_. But this variable alone
// doesn't necessarily starts a migration. A migration will be started
// later, once the current packet is confirmed to meet the following
// conditions:
// 1) current_effective_peer_migration_type_ is not NO_CHANGE.
// 2) The current packet is not a connectivity probing.
// 3) The current packet is not reordered, i.e. its packet number is the
// largest of this connection so far.
// Once the above conditions are confirmed, a new migration will start
// even if there is an active migration underway.
current_effective_peer_migration_type_ =
QuicUtils::DetermineAddressChangeType(
effective_peer_address_,
GetEffectivePeerAddressFromCurrentPacket());
QUIC_DLOG_IF(INFO, current_effective_peer_migration_type_ != NO_CHANGE)
<< ENDPOINT << "Effective peer's ip:port changed from "
<< effective_peer_address_.ToString() << " to "
<< GetEffectivePeerAddressFromCurrentPacket().ToString()
<< ", active_effective_peer_migration_type is "
<< active_effective_peer_migration_type_;
}
--stats_.packets_dropped;
QUIC_DVLOG(1) << ENDPOINT << "Received packet header: " << header;
last_header_ = header;
// Record packet receipt to populate ack info before processing stream
// frames, since the processing may result in sending a bundled ack.
uber_received_packet_manager_.RecordPacketReceived(
last_decrypted_packet_level_, last_header_,
time_of_last_received_packet_);
DCHECK(connected_);
return true;
}
bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
DCHECK(connected_);
// Since a stream frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStreamFrame(frame);
}
if (!QuicUtils::IsCryptoStreamId(transport_version(), frame.stream_id) &&
last_decrypted_packet_level_ == ENCRYPTION_INITIAL) {
if (MaybeConsiderAsMemoryCorruption(frame)) {
CloseConnection(QUIC_MAYBE_CORRUPTED_MEMORY,
"Received crypto frame on non crypto stream.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
QUIC_PEER_BUG << ENDPOINT
<< "Received an unencrypted data frame: closing connection"
<< " packet_number:" << last_header_.packet_number
<< " stream_id:" << frame.stream_id
<< " received_packets:" << ack_frame();
CloseConnection(QUIC_UNENCRYPTED_STREAM_DATA,
"Unencrypted stream data seen.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
visitor_->OnStreamFrame(frame);
stats_.stream_bytes_received += frame.data_length;
should_last_packet_instigate_acks_ = true;
consecutive_retransmittable_on_wire_ping_count_ = 0;
return connected_;
}
bool QuicConnection::OnCryptoFrame(const QuicCryptoFrame& frame) {
DCHECK(connected_);
// Since a CRYPTO frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnCryptoFrame(frame);
}
visitor_->OnCryptoFrame(frame);
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnAckFrameStart(QuicPacketNumber largest_acked,
QuicTime::Delta ack_delay_time) {
DCHECK(connected_);
if (processing_ack_frame_) {
CloseConnection(QUIC_INVALID_ACK_DATA,
"Received a new ack while processing an ack frame.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
// Since an ack frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
QUIC_DVLOG(1) << ENDPOINT
<< "OnAckFrameStart, largest_acked: " << largest_acked;
if (GetLargestReceivedPacketWithAck().IsInitialized() &&
last_header_.packet_number <= GetLargestReceivedPacketWithAck()) {
QUIC_DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
if (!GetLargestSentPacket().IsInitialized() ||
largest_acked > GetLargestSentPacket()) {
QUIC_DLOG(WARNING) << ENDPOINT
<< "Peer's observed unsent packet:" << largest_acked
<< " vs " << GetLargestSentPacket();
// We got an ack for data we have not sent.
CloseConnection(QUIC_INVALID_ACK_DATA, "Largest observed too high.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (!GetLargestAckedPacket().IsInitialized() ||
largest_acked > GetLargestAckedPacket()) {
visitor_->OnForwardProgressConfirmed();
}
processing_ack_frame_ = true;
sent_packet_manager_.OnAckFrameStart(largest_acked, ack_delay_time,
time_of_last_received_packet_);
return true;
}
bool QuicConnection::OnAckRange(QuicPacketNumber start, QuicPacketNumber end) {
DCHECK(connected_);
QUIC_DVLOG(1) << ENDPOINT << "OnAckRange: [" << start << ", " << end << ")";
if (GetLargestReceivedPacketWithAck().IsInitialized() &&
last_header_.packet_number <= GetLargestReceivedPacketWithAck()) {
QUIC_DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
sent_packet_manager_.OnAckRange(start, end);
return true;
}
bool QuicConnection::OnAckTimestamp(QuicPacketNumber packet_number,
QuicTime timestamp) {
DCHECK(connected_);
QUIC_DVLOG(1) << ENDPOINT << "OnAckTimestamp: [" << packet_number << ", "
<< timestamp.ToDebuggingValue() << ")";
if (GetLargestReceivedPacketWithAck().IsInitialized() &&
last_header_.packet_number <= GetLargestReceivedPacketWithAck()) {
QUIC_DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
sent_packet_manager_.OnAckTimestamp(packet_number, timestamp);
return true;
}
bool QuicConnection::OnAckFrameEnd(QuicPacketNumber start) {
DCHECK(connected_);
QUIC_DVLOG(1) << ENDPOINT << "OnAckFrameEnd, start: " << start;
if (GetLargestReceivedPacketWithAck().IsInitialized() &&
last_header_.packet_number <= GetLargestReceivedPacketWithAck()) {
QUIC_DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
const AckResult ack_result = sent_packet_manager_.OnAckFrameEnd(
time_of_last_received_packet_, last_header_.packet_number,
last_decrypted_packet_level_);
if (ack_result != PACKETS_NEWLY_ACKED &&
ack_result != NO_PACKETS_NEWLY_ACKED) {
// Error occurred (e.g., this ACK tries to ack packets in wrong packet
// number space), and this would cause the connection to be closed.
QUIC_DLOG(ERROR) << ENDPOINT
<< "Error occurred when processing an ACK frame: "
<< QuicUtils::AckResultToString(ack_result);
return false;
}
// Cancel the send alarm because new packets likely have been acked, which
// may change the congestion window and/or pacing rate. Canceling the alarm
// causes CanWrite to recalculate the next send time.
if (send_alarm_->IsSet()) {
send_alarm_->Cancel();
}
if (supports_release_time_) {
// Update pace time into future because smoothed RTT is likely updated.
UpdateReleaseTimeIntoFuture();
}
SetLargestReceivedPacketWithAck(last_header_.packet_number);
// If the incoming ack's packets set expresses missing packets: peer is still
// waiting for a packet lower than a packet that we are no longer planning to
// send.
// If the incoming ack's packets set expresses received packets: peer is still
// acking packets which we never care about.
// Send an ack to raise the high water mark.
bool send_stop_waiting = GetLeastUnacked() > start;
if (GetQuicReloadableFlag(quic_simplify_stop_waiting) &&
no_stop_waiting_frames_) {
QUIC_RELOADABLE_FLAG_COUNT(quic_simplify_stop_waiting);
send_stop_waiting = false;
}
PostProcessAfterAckFrame(send_stop_waiting,
ack_result == PACKETS_NEWLY_ACKED);
processing_ack_frame_ = false;
return connected_;
}
bool QuicConnection::OnStopWaitingFrame(const QuicStopWaitingFrame& frame) {
DCHECK(connected_);
// Since a stop waiting frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (no_stop_waiting_frames_) {
return true;
}
if (largest_seen_packet_with_stop_waiting_.IsInitialized() &&
last_header_.packet_number <= largest_seen_packet_with_stop_waiting_) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Received an old stop waiting frame: ignoring";
return true;
}
const char* error = ValidateStopWaitingFrame(frame);
if (error != nullptr) {
CloseConnection(QUIC_INVALID_STOP_WAITING_DATA, error,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStopWaitingFrame(frame);
}
largest_seen_packet_with_stop_waiting_ = last_header_.packet_number;
uber_received_packet_manager_.DontWaitForPacketsBefore(
last_decrypted_packet_level_, frame.least_unacked);
return connected_;
}
bool QuicConnection::OnPaddingFrame(const QuicPaddingFrame& frame) {
DCHECK(connected_);
UpdatePacketContent(SECOND_FRAME_IS_PADDING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPaddingFrame(frame);
}
return true;
}
bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
DCHECK(connected_);
UpdatePacketContent(FIRST_FRAME_IS_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPingFrame(frame);
}
should_last_packet_instigate_acks_ = true;
return true;
}
const char* QuicConnection::ValidateStopWaitingFrame(
const QuicStopWaitingFrame& stop_waiting) {
const QuicPacketNumber peer_least_packet_awaiting_ack =
uber_received_packet_manager_.peer_least_packet_awaiting_ack();
if (peer_least_packet_awaiting_ack.IsInitialized() &&
stop_waiting.least_unacked < peer_least_packet_awaiting_ack) {
QUIC_DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
<< stop_waiting.least_unacked << " vs "
<< peer_least_packet_awaiting_ack;
// We never process old ack frames, so this number should only increase.
return "Least unacked too small.";
}
if (stop_waiting.least_unacked > last_header_.packet_number) {
QUIC_DLOG(ERROR) << ENDPOINT
<< "Peer sent least_unacked:" << stop_waiting.least_unacked
<< " greater than the enclosing packet number:"
<< last_header_.packet_number;
return "Least unacked too large.";
}
return nullptr;
}
bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
DCHECK(connected_);
// Since a reset stream frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRstStreamFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT
<< "RST_STREAM_FRAME received for stream: " << frame.stream_id
<< " with error: "
<< QuicRstStreamErrorCodeToString(frame.error_code);
visitor_->OnRstStream(frame);
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnStopSendingFrame(const QuicStopSendingFrame& frame) {
DCHECK(connected_);
// Since a reset stream frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStopSendingFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT << "STOP_SENDING frame received for stream: "
<< frame.stream_id
<< " with error: " << frame.application_error_code;
visitor_->OnStopSendingFrame(frame);
return connected_;
}
bool QuicConnection::OnPathChallengeFrame(const QuicPathChallengeFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPathChallengeFrame(frame);
}
// Save the path challenge's payload, for later use in generating the
// response.
received_path_challenge_payloads_.push_back(frame.data_buffer);
// For VERSION 99 we define a "Padded PATH CHALLENGE" to be the same thing
// as a PADDED PING -- it will start a connectivity check and prevent
// connection migration. Insofar as the connectivity check and connection
// migration are concerned, logically the PATH CHALLENGE is the same as the
// PING, so as a stopgap, tell the FSM that determines whether we have a
// Padded PING or not that we received a PING.
UpdatePacketContent(FIRST_FRAME_IS_PING);
should_last_packet_instigate_acks_ = true;
return true;
}
bool QuicConnection::OnPathResponseFrame(const QuicPathResponseFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPathResponseFrame(frame);
}
should_last_packet_instigate_acks_ = true;
if (!transmitted_connectivity_probe_payload_ ||
*transmitted_connectivity_probe_payload_ != frame.data_buffer) {
// Is not for the probe we sent, ignore it.
return true;
}
// Have received the matching PATH RESPONSE, saved payload no longer valid.
transmitted_connectivity_probe_payload_ = nullptr;
UpdatePacketContent(FIRST_FRAME_IS_PING);
return true;
}
bool QuicConnection::OnConnectionCloseFrame(
const QuicConnectionCloseFrame& frame) {
DCHECK(connected_);
// Since a connection close frame was received, this is not a connectivity
// probe. A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionCloseFrame(frame);
}
switch (frame.close_type) {
case GOOGLE_QUIC_CONNECTION_CLOSE:
QUIC_DLOG(INFO) << ENDPOINT << "Received ConnectionClose for connection: "
<< connection_id() << ", with error: "
<< QuicErrorCodeToString(frame.extracted_error_code)
<< " (" << frame.error_details << ")";
break;
case IETF_QUIC_TRANSPORT_CONNECTION_CLOSE:
QUIC_DLOG(INFO) << ENDPOINT
<< "Received Transport ConnectionClose for connection: "
<< connection_id() << ", with error: "
<< QuicErrorCodeToString(frame.extracted_error_code)
<< " (" << frame.error_details << ")"
<< ", transport error code: "
<< frame.transport_error_code << ", error frame type: "
<< frame.transport_close_frame_type;
break;
case IETF_QUIC_APPLICATION_CONNECTION_CLOSE:
QUIC_DLOG(INFO) << ENDPOINT
<< "Received Application ConnectionClose for connection: "
<< connection_id() << ", with error: "
<< QuicErrorCodeToString(frame.extracted_error_code)
<< " (" << frame.error_details << ")"
<< ", application error code: "
<< frame.application_error_code;
break;
}
if (frame.extracted_error_code == QUIC_BAD_MULTIPATH_FLAG) {
QUIC_LOG_FIRST_N(ERROR, 10) << "Unexpected QUIC_BAD_MULTIPATH_FLAG error."
<< " last_received_header: " << last_header_
<< " encryption_level: " << encryption_level_;
}
TearDownLocalConnectionState(frame, ConnectionCloseSource::FROM_PEER);
return connected_;
}
bool QuicConnection::OnMaxStreamsFrame(const QuicMaxStreamsFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnMaxStreamsFrame(frame);
}
return visitor_->OnMaxStreamsFrame(frame);
}
bool QuicConnection::OnStreamsBlockedFrame(
const QuicStreamsBlockedFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStreamsBlockedFrame(frame);
}
return visitor_->OnStreamsBlockedFrame(frame);
}
bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
DCHECK(connected_);
// Since a go away frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnGoAwayFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT << "GOAWAY_FRAME received with last good stream: "
<< frame.last_good_stream_id
<< " and error: " << QuicErrorCodeToString(frame.error_code)
<< " and reason: " << frame.reason_phrase;
visitor_->OnGoAway(frame);
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) {
DCHECK(connected_);
// Since a window update frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnWindowUpdateFrame(frame, time_of_last_received_packet_);
}
QUIC_DVLOG(1) << ENDPOINT << "WINDOW_UPDATE_FRAME received for stream: "
<< frame.stream_id
<< " with byte offset: " << frame.byte_offset;
visitor_->OnWindowUpdateFrame(frame);
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnNewConnectionIdFrame(
const QuicNewConnectionIdFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnNewConnectionIdFrame(frame);
}
return true;
}
bool QuicConnection::OnRetireConnectionIdFrame(
const QuicRetireConnectionIdFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRetireConnectionIdFrame(frame);
}
return true;
}
bool QuicConnection::OnNewTokenFrame(const QuicNewTokenFrame& frame) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnNewTokenFrame(frame);
}
return true;
}
bool QuicConnection::OnMessageFrame(const QuicMessageFrame& frame) {
DCHECK(connected_);
// Since a message frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnMessageFrame(frame);
}
visitor_->OnMessageReceived(
QuicStringPiece(frame.data, frame.message_length));
should_last_packet_instigate_acks_ = true;
return connected_;
}
bool QuicConnection::OnBlockedFrame(const QuicBlockedFrame& frame) {
DCHECK(connected_);
// Since a blocked frame was received, this is not a connectivity probe.
// A probe only contains a PING and full padding.
UpdatePacketContent(NOT_PADDED_PING);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnBlockedFrame(frame);
}
QUIC_DLOG(INFO) << ENDPOINT
<< "BLOCKED_FRAME received for stream: " << frame.stream_id;
visitor_->OnBlockedFrame(frame);
stats_.blocked_frames_received++;
should_last_packet_instigate_acks_ = true;
return connected_;
}
void QuicConnection::OnPacketComplete() {
// Don't do anything if this packet closed the connection.
if (!connected_) {
ClearLastFrames();
return;
}
if (IsCurrentPacketConnectivityProbing()) {
++stats_.num_connectivity_probing_received;
}
QUIC_DVLOG(1) << ENDPOINT << "Got"
<< (SupportsMultiplePacketNumberSpaces()
? (" " + EncryptionLevelToString(
last_decrypted_packet_level_))
: "")
<< " packet " << last_header_.packet_number << " for "
<< GetServerConnectionIdAsRecipient(last_header_, perspective_);
QUIC_DLOG_IF(INFO, current_packet_content_ == SECOND_FRAME_IS_PADDING)
<< ENDPOINT << "Received a padded PING packet. is_probing: "
<< IsCurrentPacketConnectivityProbing();
if (IsCurrentPacketConnectivityProbing()) {
QUIC_DVLOG(1) << ENDPOINT << "Received a connectivity probing packet for "
<< GetServerConnectionIdAsRecipient(last_header_,
perspective_)
<< " from ip:port: " << last_packet_source_address_.ToString()
<< " to ip:port: "
<< last_packet_destination_address_.ToString();
visitor_->OnPacketReceived(last_packet_destination_address_,
last_packet_source_address_,
/*is_connectivity_probe=*/true);
} else if (perspective_ == Perspective::IS_CLIENT) {
// This node is a client, notify that a speculative connectivity probing
// packet has been received anyway.
QUIC_DVLOG(1) << ENDPOINT
<< "Received a speculative connectivity probing packet for "
<< GetServerConnectionIdAsRecipient(last_header_,
perspective_)
<< " from ip:port: " << last_packet_source_address_.ToString()
<< " to ip:port: "
<< last_packet_destination_address_.ToString();
visitor_->OnPacketReceived(last_packet_destination_address_,
last_packet_source_address_,
/*is_connectivity_probe=*/false);
} else {
// This node is not a client (is a server) AND the received packet was
// NOT connectivity-probing. If the packet had PATH CHALLENGES, send
// appropriate RESPONSE. Then deal with possible peer migration.
if (VersionHasIetfQuicFrames(transport_version()) &&
!received_path_challenge_payloads_.empty()) {
// If a PATH CHALLENGE was in a "Padded PING (or PATH CHALLENGE)"
// then it is taken care of above. This handles the case where a PATH
// CHALLENGE appeared someplace else (eg, the peer randomly added a PATH
// CHALLENGE frame to some other packet.
// There was at least one PATH CHALLENGE in the received packet,
// Generate the required PATH RESPONSE.
SendGenericPathProbePacket(nullptr, last_packet_source_address_,
/* is_response= */ true);
}
if (last_header_.packet_number == GetLargestReceivedPacket()) {
direct_peer_address_ = last_packet_source_address_;
if (current_effective_peer_migration_type_ != NO_CHANGE) {
// TODO(fayang): When multiple packet number spaces is supported, only
// start peer migration for the application data.
StartEffectivePeerMigration(current_effective_peer_migration_type_);
}
}
}
current_effective_peer_migration_type_ = NO_CHANGE;
// Some encryption levels share a packet number space, it is therefore
// possible for us to want to ack some packets even though we do not yet
// have the appropriate keys to encrypt the acks. In this scenario we
// do not update the ACK timeout. This can happen for example with
// IETF QUIC on the server when we receive 0-RTT packets and do not yet
// have 1-RTT keys (0-RTT packets are acked at the 1-RTT level).
// Note that this could cause slight performance degradations in the edge
// case where one packet is received, then the encrypter is installed,
// then a second packet is received; as that could cause the ACK for the
// second packet to be delayed instead of immediate. This is currently
// considered to be small enough of an edge case to not be optimized for.
if (!SupportsMultiplePacketNumberSpaces() ||
framer_.HasEncrypterOfEncryptionLevel(QuicUtils::GetEncryptionLevel(
QuicUtils::GetPacketNumberSpace(last_decrypted_packet_level_)))) {
uber_received_packet_manager_.MaybeUpdateAckTimeout(
should_last_packet_instigate_acks_, last_decrypted_packet_level_,
last_header_.packet_number, time_of_last_received_packet_,
clock_->ApproximateNow(), sent_packet_manager_.GetRttStats());
} else {
QUIC_DLOG(INFO) << ENDPOINT << "Not updating ACK timeout for "
<< EncryptionLevelToString(last_decrypted_packet_level_)
<< " as we do not have the corresponding encrypter";
}
ClearLastFrames();
CloseIfTooManyOutstandingSentPackets();
}
bool QuicConnection::IsValidStatelessResetToken(QuicUint128 token) const {
return stateless_reset_token_received_ &&
token == received_stateless_reset_token_;
}
void QuicConnection::OnAuthenticatedIetfStatelessResetPacket(
const QuicIetfStatelessResetPacket& /*packet*/) {
// TODO(fayang): Add OnAuthenticatedIetfStatelessResetPacket to
// debug_visitor_.
const std::string error_details = "Received stateless reset.";
QUIC_CODE_COUNT(quic_tear_down_local_connection_on_stateless_reset);
TearDownLocalConnectionState(QUIC_PUBLIC_RESET, error_details,
ConnectionCloseSource::FROM_PEER);
}
void QuicConnection::ClearLastFrames() {
should_last_packet_instigate_acks_ = false;
}
void QuicConnection::CloseIfTooManyOutstandingSentPackets() {
// This occurs if we don't discard old packets we've seen fast enough. It's
// possible largest observed is less than leaset unacked.
if (sent_packet_manager_.GetLargestObserved().IsInitialized() &&
sent_packet_manager_.GetLargestObserved() >
sent_packet_manager_.GetLeastUnacked() + max_tracked_packets_) {
CloseConnection(
QUIC_TOO_MANY_OUTSTANDING_SENT_PACKETS,
QuicStrCat("More than ", max_tracked_packets_,
" outstanding, least_unacked: ",
sent_packet_manager_.GetLeastUnacked().ToUint64(),
", packets_processed: ", stats_.packets_processed,
", last_decrypted_packet_level: ",
EncryptionLevelToString(last_decrypted_packet_level_)),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
}
const QuicFrame QuicConnection::GetUpdatedAckFrame() {
return uber_received_packet_manager_.GetUpdatedAckFrame(
QuicUtils::GetPacketNumberSpace(encryption_level_),
clock_->ApproximateNow());
}
void QuicConnection::PopulateStopWaitingFrame(
QuicStopWaitingFrame* stop_waiting) {
stop_waiting->least_unacked = GetLeastUnacked();
}
QuicPacketNumber QuicConnection::GetLeastUnacked() const {
return sent_packet_manager_.GetLeastUnacked();
}
bool QuicConnection::HandleWriteBlocked() {
if (!writer_->IsWriteBlocked()) {
return false;
}
visitor_->OnWriteBlocked();
return true;
}
void QuicConnection::MaybeSendInResponseToPacket() {
if (!connected_) {
return;
}
// If the writer is blocked, don't attempt to send packets now or in the send
// alarm. When the writer unblocks, OnCanWrite() will be called for this
// connection to send.
if (HandleWriteBlocked()) {
return;
}
// Now that we have received an ack, we might be able to send packets which
// are queued locally, or drain streams which are blocked.
if (defer_send_in_response_to_packets_) {
send_alarm_->Update(clock_->ApproximateNow(), QuicTime::Delta::Zero());
} else {
WriteAndBundleAcksIfNotBlocked();
}
}
void QuicConnection::SendVersionNegotiationPacket(bool ietf_quic,
bool has_length_prefix) {
pending_version_negotiation_packet_ = true;
send_ietf_version_negotiation_packet_ = ietf_quic;
send_version_negotiation_packet_with_prefixed_lengths_ = has_length_prefix;
if (HandleWriteBlocked()) {
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Sending version negotiation packet: {"
<< ParsedQuicVersionVectorToString(
framer_.supported_versions())
<< "}, " << (ietf_quic ? "" : "!") << "ietf_quic";
std::unique_ptr<QuicEncryptedPacket> version_packet(
packet_generator_.SerializeVersionNegotiationPacket(
ietf_quic, has_length_prefix, framer_.supported_versions()));
QUIC_DVLOG(2) << ENDPOINT << "Sending version negotiation packet: {"
<< ParsedQuicVersionVectorToString(framer_.supported_versions())
<< "}, " << (ietf_quic ? "" : "!") << "ietf_quic:" << std::endl
<< QuicTextUtils::HexDump(QuicStringPiece(
version_packet->data(), version_packet->length()));
WriteResult result = writer_->WritePacket(
version_packet->data(), version_packet->length(), self_address().host(),
peer_address(), per_packet_options_);
if (IsWriteError(result.status)) {
OnWriteError(result.error_code);
return;
}
if (IsWriteBlockedStatus(result.status)) {
visitor_->OnWriteBlocked();
if (result.status == WRITE_STATUS_BLOCKED_DATA_BUFFERED) {
pending_version_negotiation_packet_ = false;
}
return;
}
pending_version_negotiation_packet_ = false;
}
size_t QuicConnection::SendCryptoData(EncryptionLevel level,
size_t write_length,
QuicStreamOffset offset) {
if (write_length == 0) {
QUIC_BUG << "Attempt to send empty crypto frame";
return 0;
}
if (!ShouldGeneratePacket(HAS_RETRANSMITTABLE_DATA, IS_HANDSHAKE)) {
return 0;
}
ScopedPacketFlusher flusher(this);
return packet_generator_.ConsumeCryptoData(level, write_length, offset);
}
QuicConsumedData QuicConnection::SendStreamData(QuicStreamId id,
size_t write_length,
QuicStreamOffset offset,
StreamSendingState state) {
if (state == NO_FIN && write_length == 0) {
QUIC_BUG << "Attempt to send empty stream frame";
return QuicConsumedData(0, false);
}
// Opportunistically bundle an ack with every outgoing packet.
// Particularly, we want to bundle with handshake packets since we don't know
// which decrypter will be used on an ack packet following a handshake
// packet (a handshake packet from client to server could result in a REJ or a
// SHLO from the server, leading to two different decrypters at the server.)
ScopedPacketFlusher flusher(this);
return packet_generator_.ConsumeData(id, write_length, offset, state);
}
bool QuicConnection::SendControlFrame(const QuicFrame& frame) {
if (SupportsMultiplePacketNumberSpaces() &&
(encryption_level_ == ENCRYPTION_INITIAL ||
encryption_level_ == ENCRYPTION_HANDSHAKE) &&
frame.type != PING_FRAME) {
// Allow PING frame to be sent without APPLICATION key. For example, when
// anti-amplification limit is used, client needs to send something to avoid
// handshake deadlock.
QUIC_DVLOG(1) << ENDPOINT << "Failed to send control frame: " << frame
<< " at encryption level: "
<< EncryptionLevelToString(encryption_level_);
return false;
}
ScopedPacketFlusher flusher(this);
const bool consumed =
packet_generator_.ConsumeRetransmittableControlFrame(frame);
if (!consumed) {
QUIC_DVLOG(1) << ENDPOINT << "Failed to send control frame: " << frame;
return false;
}
if (frame.type == PING_FRAME) {
// Flush PING frame immediately.
packet_generator_.FlushAllQueuedFrames();
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPingSent();
}
}
if (frame.type == BLOCKED_FRAME) {
stats_.blocked_frames_sent++;
}
return true;
}
void QuicConnection::OnStreamReset(QuicStreamId id,
QuicRstStreamErrorCode error) {
if (error == QUIC_STREAM_NO_ERROR) {
// All data for streams which are reset with QUIC_STREAM_NO_ERROR must
// be received by the peer.
return;
}
// Flush stream frames of reset stream.
if (packet_generator_.HasPendingStreamFramesOfStream(id)) {
ScopedPacketFlusher flusher(this);
packet_generator_.FlushAllQueuedFrames();
}
sent_packet_manager_.CancelRetransmissionsForStream(id);
// Remove all queued packets which only contain data for the reset stream.
// TODO(fayang): consider removing this because it should be rarely executed.
auto packet_iterator = queued_packets_.begin();
while (packet_iterator != queued_packets_.end()) {
QuicFrames* retransmittable_frames =
&packet_iterator->retransmittable_frames;
if (retransmittable_frames->empty()) {
++packet_iterator;
continue;
}
// NOTE THAT RemoveFramesForStream removes only STREAM frames
// for the specified stream.
RemoveFramesForStream(retransmittable_frames, id);
if (!retransmittable_frames->empty()) {
++packet_iterator;
continue;
}
delete[] packet_iterator->encrypted_buffer;
ClearSerializedPacket(&(*packet_iterator));
packet_iterator = queued_packets_.erase(packet_iterator);
}
// TODO(ianswett): Consider checking for 3 RTOs when the last stream is
// cancelled as well.
}
const QuicConnectionStats& QuicConnection::GetStats() {
const RttStats* rtt_stats = sent_packet_manager_.GetRttStats();
// Update rtt and estimated bandwidth.
QuicTime::Delta min_rtt = rtt_stats->min_rtt();
if (min_rtt.IsZero()) {
// If min RTT has not been set, use initial RTT instead.
min_rtt = rtt_stats->initial_rtt();
}
stats_.min_rtt_us = min_rtt.ToMicroseconds();
QuicTime::Delta srtt = rtt_stats->SmoothedOrInitialRtt();
stats_.srtt_us = srtt.ToMicroseconds();
stats_.estimated_bandwidth = sent_packet_manager_.BandwidthEstimate();
stats_.max_packet_size = packet_generator_.GetCurrentMaxPacketLength();
stats_.max_received_packet_size = largest_received_packet_size_;
return stats_;
}
void QuicConnection::OnCoalescedPacket(const QuicEncryptedPacket& packet) {
QueueCoalescedPacket(packet);
}
void QuicConnection::OnUndecryptablePacket(const QuicEncryptedPacket& packet,
EncryptionLevel decryption_level,
bool has_decryption_key) {
QUIC_DVLOG(1) << ENDPOINT << "Received undecryptable packet of length "
<< packet.length() << " with"
<< (has_decryption_key ? "" : "out") << " key at level "
<< EncryptionLevelToString(decryption_level)
<< " while connection is at encryption level "
<< EncryptionLevelToString(encryption_level_);
DCHECK(EncryptionLevelIsValid(decryption_level));
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE) {
++stats_.undecryptable_packets_received_before_handshake_complete;
}
bool should_enqueue = true;
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE) {
// We do not expect to install any further keys.
should_enqueue = false;
} else if (undecryptable_packets_.size() >= max_undecryptable_packets_) {
// We do not queue more than max_undecryptable_packets_ packets.
should_enqueue = false;
} else if (has_decryption_key) {
// We already have the key for this decryption level, therefore no
// future keys will allow it be decrypted.
should_enqueue = false;
} else if (version().KnowsWhichDecrypterToUse() &&
decryption_level <= encryption_level_) {
// On versions that know which decrypter to use, we install keys in order
// so we will not get newer keys for lower encryption levels.
should_enqueue = false;
}
if (should_enqueue) {
QueueUndecryptablePacket(packet);
} else if (debug_visitor_ != nullptr) {
debug_visitor_->OnUndecryptablePacket();
}
}
void QuicConnection::ProcessUdpPacket(const QuicSocketAddress& self_address,
const QuicSocketAddress& peer_address,
const QuicReceivedPacket& packet) {
if (!connected_) {
return;
}
QUIC_DVLOG(2) << ENDPOINT << "Received encrypted " << packet.length()
<< " bytes:" << std::endl
<< QuicTextUtils::HexDump(
QuicStringPiece(packet.data(), packet.length()));
QUIC_BUG_IF(current_packet_data_ != nullptr)
<< "ProcessUdpPacket must not be called while processing a packet.";
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
}
last_size_ = packet.length();
current_packet_data_ = packet.data();
last_packet_destination_address_ = self_address;
last_packet_source_address_ = peer_address;
if (!self_address_.IsInitialized()) {
self_address_ = last_packet_destination_address_;
}
if (!direct_peer_address_.IsInitialized()) {
direct_peer_address_ = last_packet_source_address_;
}
if (!effective_peer_address_.IsInitialized()) {
const QuicSocketAddress effective_peer_addr =
GetEffectivePeerAddressFromCurrentPacket();
// effective_peer_address_ must be initialized at the beginning of the
// first packet processed(here). If effective_peer_addr is uninitialized,
// just set effective_peer_address_ to the direct peer address.
effective_peer_address_ = effective_peer_addr.IsInitialized()
? effective_peer_addr
: direct_peer_address_;
}
stats_.bytes_received += packet.length();
++stats_.packets_received;
if (EnforceAntiAmplificationLimit()) {
bytes_received_before_address_validation_ += last_size_;
}
// Ensure the time coming from the packet reader is within 2 minutes of now.
if (std::abs((packet.receipt_time() - clock_->ApproximateNow()).ToSeconds()) >
2 * 60) {
QUIC_BUG << "Packet receipt time:"
<< packet.receipt_time().ToDebuggingValue()
<< " too far from current time:"
<< clock_->ApproximateNow().ToDebuggingValue();
}
time_of_last_received_packet_ = packet.receipt_time();
QUIC_DVLOG(1) << ENDPOINT << "time of last received packet: "
<< time_of_last_received_packet_.ToDebuggingValue();
ScopedPacketFlusher flusher(this);
if (!framer_.ProcessPacket(packet)) {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
QUIC_DVLOG(1) << ENDPOINT
<< "Unable to process packet. Last packet processed: "
<< last_header_.packet_number;
current_packet_data_ = nullptr;
is_current_packet_connectivity_probing_ = false;
MaybeProcessCoalescedPackets();
return;
}
++stats_.packets_processed;
QUIC_DLOG_IF(INFO, active_effective_peer_migration_type_ != NO_CHANGE)
<< "sent_packet_manager_.GetLargestObserved() = "
<< sent_packet_manager_.GetLargestObserved()
<< ", highest_packet_sent_before_effective_peer_migration_ = "
<< highest_packet_sent_before_effective_peer_migration_;
if (active_effective_peer_migration_type_ != NO_CHANGE &&
sent_packet_manager_.GetLargestObserved().IsInitialized() &&
(!highest_packet_sent_before_effective_peer_migration_.IsInitialized() ||
sent_packet_manager_.GetLargestObserved() >
highest_packet_sent_before_effective_peer_migration_)) {
if (perspective_ == Perspective::IS_SERVER) {
OnEffectivePeerMigrationValidated();
}
}
MaybeProcessCoalescedPackets();
MaybeProcessUndecryptablePackets();
MaybeSendInResponseToPacket();
SetPingAlarm();
current_packet_data_ = nullptr;
is_current_packet_connectivity_probing_ = false;
}
void QuicConnection::OnBlockedWriterCanWrite() {
writer_->SetWritable();
OnCanWrite();
}
void QuicConnection::OnCanWrite() {
if (!connected_) {
return;
}
DCHECK(!writer_->IsWriteBlocked());
// Add a flusher to ensure the connection is marked app-limited.
ScopedPacketFlusher flusher(this);
WriteQueuedPackets();
const QuicTime ack_timeout =
uber_received_packet_manager_.GetEarliestAckTimeout();
if (ack_timeout.IsInitialized() && ack_timeout <= clock_->ApproximateNow()) {
// Send an ACK now because either 1) we were write blocked when we last
// tried to send an ACK, or 2) both ack alarm and send alarm were set to
// go off together.
if (SupportsMultiplePacketNumberSpaces()) {
SendAllPendingAcks();
} else {
SendAck();
}
}
if (!session_decides_what_to_write()) {
WritePendingRetransmissions();
}
WriteNewData();
}
void QuicConnection::WriteNewData() {
// Sending queued packets may have caused the socket to become write blocked,
// or the congestion manager to prohibit sending. If we've sent everything
// we had queued and we're still not blocked, let the visitor know it can
// write more.
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
return;
}
{
ScopedPacketFlusher flusher(this);
visitor_->OnCanWrite();
}
// After the visitor writes, it may have caused the socket to become write
// blocked or the congestion manager to prohibit sending, so check again.
if (visitor_->WillingAndAbleToWrite() && !send_alarm_->IsSet() &&
CanWrite(HAS_RETRANSMITTABLE_DATA)) {
// We're not write blocked, but some stream didn't write out all of its
// bytes. Register for 'immediate' resumption so we'll keep writing after
// other connections and events have had a chance to use the thread.
send_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::WriteIfNotBlocked() {
if (!HandleWriteBlocked()) {
OnCanWrite();
}
}
void QuicConnection::WriteAndBundleAcksIfNotBlocked() {
if (!HandleWriteBlocked()) {
ScopedPacketFlusher flusher(this);
WriteIfNotBlocked();
}
}
bool QuicConnection::ProcessValidatedPacket(const QuicPacketHeader& header) {
if (perspective_ == Perspective::IS_SERVER && self_address_.IsInitialized() &&
last_packet_destination_address_.IsInitialized() &&
self_address_ != last_packet_destination_address_) {
// Allow change between pure IPv4 and equivalent mapped IPv4 address.
if (self_address_.port() != last_packet_destination_address_.port() ||
self_address_.host().Normalized() !=
last_packet_destination_address_.host().Normalized()) {
if (!visitor_->AllowSelfAddressChange()) {
CloseConnection(
QUIC_ERROR_MIGRATING_ADDRESS,
"Self address migration is not supported at the server.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
}
self_address_ = last_packet_destination_address_;
}
if (PacketCanReplaceConnectionId(header, perspective_) &&
server_connection_id_ != header.source_connection_id) {
QUIC_DLOG(INFO) << ENDPOINT << "Replacing connection ID "
<< server_connection_id_ << " with "
<< header.source_connection_id;
server_connection_id_ = header.source_connection_id;
packet_generator_.SetServerConnectionId(server_connection_id_);
}
if (!ValidateReceivedPacketNumber(header.packet_number)) {
return false;
}
if (!version_negotiated_) {
if (perspective_ == Perspective::IS_CLIENT) {
DCHECK(!header.version_flag || header.form != GOOGLE_QUIC_PACKET);
if (!VersionHasIetfInvariantHeader(framer_.transport_version())) {
// If the client gets a packet without the version flag from the server
// it should stop sending version since the version negotiation is done.
// IETF QUIC stops sending version once encryption level switches to
// forward secure.
packet_generator_.StopSendingVersion();
}
version_negotiated_ = true;
visitor_->OnSuccessfulVersionNegotiation(version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(version());
}
}
}
if (last_size_ > largest_received_packet_size_) {
largest_received_packet_size_ = last_size_;
}
if (perspective_ == Perspective::IS_SERVER &&
encryption_level_ == ENCRYPTION_INITIAL &&
last_size_ > packet_generator_.GetCurrentMaxPacketLength()) {
SetMaxPacketLength(last_size_);
}
return true;
}
bool QuicConnection::ValidateReceivedPacketNumber(
QuicPacketNumber packet_number) {
// If this packet has already been seen, or the sender has told us that it
// will not be retransmitted, then stop processing the packet.
if (!uber_received_packet_manager_.IsAwaitingPacket(
last_decrypted_packet_level_, packet_number)) {
QUIC_DLOG(INFO) << ENDPOINT << "Packet " << packet_number
<< " no longer being waited for at level "
<< static_cast<int>(last_decrypted_packet_level_)
<< ". Discarding.";
if (debug_visitor_ != nullptr) {
debug_visitor_->OnDuplicatePacket(packet_number);
}
return false;
}
return true;
}
void QuicConnection::WriteQueuedPackets() {
DCHECK(!writer_->IsWriteBlocked());
if (pending_version_negotiation_packet_) {
SendVersionNegotiationPacket(
send_ietf_version_negotiation_packet_,
send_version_negotiation_packet_with_prefixed_lengths_);
}
QUIC_CLIENT_HISTOGRAM_COUNTS("QuicSession.NumQueuedPacketsBeforeWrite",
queued_packets_.size(), 1, 1000, 50, "");
while (!queued_packets_.empty()) {
DCHECK(!treat_queued_packets_as_sent_);
// WritePacket() can potentially clear all queued packets, so we need to
// save the first queued packet to a local variable before calling it.
SerializedPacket packet(std::move(queued_packets_.front()));
queued_packets_.pop_front();
const bool write_result = WritePacket(&packet);
if (connected_ && !write_result) {
// Write failed but connection is open, re-insert |packet| into the
// front of the queue, it will be retried later.
queued_packets_.emplace_front(std::move(packet));
break;
}
delete[] packet.encrypted_buffer;
ClearSerializedPacket(&packet);
if (!connected_) {
DCHECK(queued_packets_.empty()) << "Queued packets should have been "
"cleared while closing connection";
break;
}
// Continue to send the next packet in queue.
}
while (!buffered_packets_.empty()) {
DCHECK(treat_queued_packets_as_sent_);
QUIC_RELOADABLE_FLAG_COUNT_N(quic_treat_queued_packets_as_sent, 1, 3);
if (HandleWriteBlocked()) {
break;
}
const BufferedPacket& packet = buffered_packets_.front();
WriteResult result = writer_->WritePacket(
packet.encrypted_buffer.data(), packet.encrypted_buffer.length(),
packet.self_address.host(), packet.peer_address, per_packet_options_);
QUIC_DVLOG(1) << ENDPOINT << "Sending buffered packet, result: " << result;
if (IsMsgTooBig(result) &&
packet.encrypted_buffer.length() > long_term_mtu_) {
// When MSG_TOO_BIG is returned, the system typically knows what the
// actual MTU is, so there is no need to probe further.
// TODO(wub): Reduce max packet size to a safe default, or the actual MTU.
mtu_discoverer_.Disable();
mtu_discovery_alarm_->Cancel();
continue;
}
if (IsWriteError(result.status)) {
OnWriteError(result.error_code);
break;
}
if (result.status == WRITE_STATUS_OK ||
result.status == WRITE_STATUS_BLOCKED_DATA_BUFFERED) {
buffered_packets_.pop_front();
}
if (IsWriteBlockedStatus(result.status)) {
visitor_->OnWriteBlocked();
break;
}
}
}
void QuicConnection::WritePendingRetransmissions() {
DCHECK(!session_decides_what_to_write());
// Keep writing as long as there's a pending retransmission which can be
// written.
while (sent_packet_manager_.HasPendingRetransmissions() &&
CanWrite(HAS_RETRANSMITTABLE_DATA)) {
const QuicPendingRetransmission pending =
sent_packet_manager_.NextPendingRetransmission();
// Re-packetize the frames with a new packet number for retransmission.
// Retransmitted packets use the same packet number length as the
// original.
// Flush the packet generator before making a new packet.
// TODO(ianswett): Implement ReserializeAllFrames as a separate path that
// does not require the creator to be flushed.
// TODO(fayang): FlushAllQueuedFrames should only be called once, and should
// be moved outside of the loop. Also, CanWrite is not checked after the
// generator is flushed.
{
ScopedPacketFlusher flusher(this);
packet_generator_.FlushAllQueuedFrames();
}
DCHECK(!packet_generator_.HasPendingFrames());
char buffer[kMaxOutgoingPacketSize];
packet_generator_.ReserializeAllFrames(pending, buffer,
kMaxOutgoingPacketSize);
}
}
void QuicConnection::SendProbingRetransmissions() {
while (sent_packet_manager_.GetSendAlgorithm()->ShouldSendProbingPacket() &&
CanWrite(HAS_RETRANSMITTABLE_DATA)) {
if (!visitor_->SendProbingData()) {
QUIC_DVLOG(1)
<< "Cannot send probing retransmissions: nothing to retransmit.";
break;
}
if (!session_decides_what_to_write()) {
DCHECK(sent_packet_manager_.HasPendingRetransmissions());
WritePendingRetransmissions();
}
}
}
void QuicConnection::RetransmitUnackedPackets(
TransmissionType retransmission_type) {
sent_packet_manager_.RetransmitUnackedPackets(retransmission_type);
WriteIfNotBlocked();
}
void QuicConnection::NeuterUnencryptedPackets() {
sent_packet_manager_.NeuterUnencryptedPackets();
// This may have changed the retransmission timer, so re-arm it.
SetRetransmissionAlarm();
}
bool QuicConnection::ShouldGeneratePacket(
HasRetransmittableData retransmittable,
IsHandshake handshake) {
// We should serialize handshake packets immediately to ensure that they
// end up sent at the right encryption level.
if (handshake == IS_HANDSHAKE) {
if (LimitedByAmplificationFactor()) {
// Server is constrained by the amplification restriction.
QUIC_DVLOG(1) << ENDPOINT << "Constrained by amplification restriction";
return false;
}
return true;
}
return CanWrite(retransmittable);
}
const QuicFrames QuicConnection::MaybeBundleAckOpportunistically() {
QuicFrames frames;
const bool has_pending_ack =
uber_received_packet_manager_
.GetAckTimeout(QuicUtils::GetPacketNumberSpace(encryption_level_))
.IsInitialized();
if (!has_pending_ack && stop_waiting_count_ <= 1) {
// No need to send an ACK.
return frames;
}
ResetAckStates();
QUIC_DVLOG(1) << ENDPOINT << "Bundle an ACK opportunistically";
QuicFrame updated_ack_frame = GetUpdatedAckFrame();
QUIC_BUG_IF(updated_ack_frame.ack_frame->packets.Empty())
<< ENDPOINT << "Attempted to opportunistically bundle an empty "
<< EncryptionLevelToString(encryption_level_) << " ACK, "
<< (has_pending_ack ? "" : "!") << "has_pending_ack, stop_waiting_count_ "
<< stop_waiting_count_;
frames.push_back(updated_ack_frame);
if (!no_stop_waiting_frames_) {
QuicStopWaitingFrame stop_waiting;
PopulateStopWaitingFrame(&stop_waiting);
frames.push_back(QuicFrame(stop_waiting));
}
return frames;
}
bool QuicConnection::CanWrite(HasRetransmittableData retransmittable) {
if (!connected_) {
return false;
}
if (session_decides_what_to_write() &&
sent_packet_manager_.pending_timer_transmission_count() > 0) {
// Force sending the retransmissions for HANDSHAKE, TLP, RTO, PROBING cases.
return true;
}
if (HandleWriteBlocked()) {
return false;
}
// Allow acks to be sent immediately.
if (retransmittable == NO_RETRANSMITTABLE_DATA) {
return true;
}
// If the send alarm is set, wait for it to fire.
if (send_alarm_->IsSet()) {
return false;
}
QuicTime now = clock_->Now();
QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(now);
if (delay.IsInfinite()) {
send_alarm_->Cancel();
return false;
}
// Scheduler requires a delay.
if (!delay.IsZero()) {
if (delay <= release_time_into_future_) {
// Required delay is within pace time into future, send now.
return true;
}
// Cannot send packet now because delay is too far in the future.
send_alarm_->Update(now + delay, QuicTime::Delta::FromMilliseconds(1));
QUIC_DVLOG(1) << ENDPOINT << "Delaying sending " << delay.ToMilliseconds()
<< "ms";
return false;
}
return true;
}
bool QuicConnection::WritePacket(SerializedPacket* packet) {
if (ShouldDiscardPacket(*packet)) {
++stats_.packets_discarded;
return true;
}
if (sent_packet_manager_.GetLargestSentPacket().IsInitialized() &&
packet->packet_number < sent_packet_manager_.GetLargestSentPacket()) {
QUIC_BUG << "Attempt to write packet:" << packet->packet_number
<< " after:" << sent_packet_manager_.GetLargestSentPacket();
QUIC_CLIENT_HISTOGRAM_COUNTS("QuicSession.NumQueuedPacketsAtOutOfOrder",
queued_packets_.size(), 1, 1000, 50, "");
CloseConnection(QUIC_INTERNAL_ERROR, "Packet written out of order.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return true;
}
SerializedPacketFate fate = DeterminePacketFate();
// Termination packets are encrypted and saved, so don't exit early.
const bool is_termination_packet = IsTerminationPacket(*packet);
if (!treat_queued_packets_as_sent_ && HandleWriteBlocked() &&
!is_termination_packet) {
return false;
}
QuicPacketNumber packet_number = packet->packet_number;
QuicPacketLength encrypted_length = packet->encrypted_length;
// Termination packets are eventually owned by TimeWaitListManager.
// Others are deleted at the end of this call.
if (is_termination_packet) {
if (termination_packets_ == nullptr) {
termination_packets_.reset(
new std::vector<std::unique_ptr<QuicEncryptedPacket>>);
}
// Copy the buffer so it's owned in the future.
char* buffer_copy = CopyBuffer(*packet);
termination_packets_->emplace_back(
new QuicEncryptedPacket(buffer_copy, encrypted_length, true));
// This assures we won't try to write *forced* packets when blocked.
// Return true to stop processing.
if (!treat_queued_packets_as_sent_ && HandleWriteBlocked()) {
return true;
}
}
const bool looks_like_mtu_probe = packet->retransmittable_frames.empty() &&
packet->encrypted_length > long_term_mtu_;
DCHECK_LE(encrypted_length, kMaxOutgoingPacketSize);
if (!looks_like_mtu_probe) {
DCHECK_LE(encrypted_length, packet_generator_.GetCurrentMaxPacketLength());
}
QUIC_DVLOG(1) << ENDPOINT << "Sending packet " << packet_number << " : "
<< (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA
? "data bearing "
: " ack only ")
<< ", encryption level: "
<< EncryptionLevelToString(packet->encryption_level)
<< ", encrypted length:" << encrypted_length;
QUIC_DVLOG(2) << ENDPOINT << "packet(" << packet_number << "): " << std::endl
<< QuicTextUtils::HexDump(QuicStringPiece(
packet->encrypted_buffer, encrypted_length));
// Measure the RTT from before the write begins to avoid underestimating the
// min_rtt_, especially in cases where the thread blocks or gets swapped out
// during the WritePacket below.
QuicTime packet_send_time = clock_->Now();
if (supports_release_time_ && per_packet_options_ != nullptr) {
QuicTime next_release_time = sent_packet_manager_.GetNextReleaseTime();
QuicTime::Delta release_time_delay = QuicTime::Delta::Zero();
QuicTime now = packet_send_time;
if (next_release_time > now) {
release_time_delay = next_release_time - now;
// Set packet_send_time to the future to make the RTT estimation accurate.
packet_send_time = next_release_time;
}
per_packet_options_->release_time_delay = release_time_delay;
}
WriteResult result(WRITE_STATUS_OK, encrypted_length);
switch (fate) {
case COALESCE:
DCHECK(false);
break;
case BUFFER:
DCHECK(treat_queued_packets_as_sent_);
QUIC_RELOADABLE_FLAG_COUNT_N(quic_treat_queued_packets_as_sent, 2, 3);
QUIC_DVLOG(1) << ENDPOINT << "Adding packet: " << packet->packet_number
<< " to buffered packets";
buffered_packets_.emplace_back(*packet, self_address(), peer_address());
break;
case SEND_TO_WRITER:
result = writer_->WritePacket(packet->encrypted_buffer, encrypted_length,
self_address().host(), peer_address(),
per_packet_options_);
break;
default:
DCHECK(false);
break;
}
QUIC_HISTOGRAM_ENUM(
"QuicConnection.WritePacketStatus", result.status,
WRITE_STATUS_NUM_VALUES,
"Status code returned by writer_->WritePacket() in QuicConnection.");
if (IsWriteBlockedStatus(result.status)) {
// Ensure the writer is still write blocked, otherwise QUIC may continue
// trying to write when it will not be able to.
DCHECK(writer_->IsWriteBlocked());
visitor_->OnWriteBlocked();
// If the socket buffers the data, then the packet should not
// be queued and sent again, which would result in an unnecessary
// duplicate packet being sent. The helper must call OnCanWrite
// when the write completes, and OnWriteError if an error occurs.
if (result.status != WRITE_STATUS_BLOCKED_DATA_BUFFERED) {
if (treat_queued_packets_as_sent_) {
QUIC_RELOADABLE_FLAG_COUNT_N(quic_treat_queued_packets_as_sent, 3, 3);
QUIC_DVLOG(1) << ENDPOINT << "Adding packet: " << packet->packet_number
<< " to buffered packets";
buffered_packets_.emplace_back(*packet, self_address(), peer_address());
} else {
return false;
}
}
}
// In some cases, an MTU probe can cause EMSGSIZE. This indicates that the
// MTU discovery is permanently unsuccessful.
if (IsMsgTooBig(result) && looks_like_mtu_probe) {
if (mtu_discovery_v2_) {
// When MSG_TOO_BIG is returned, the system typically knows what the
// actual MTU is, so there is no need to probe further.
// TODO(wub): Reduce max packet size to a safe default, or the actual MTU.
QUIC_DVLOG(1) << ENDPOINT << " MTU probe packet too big, size:"
<< packet->encrypted_length
<< ", long_term_mtu_:" << long_term_mtu_;
mtu_discoverer_.Disable();
} else {
mtu_discovery_target_ = 0;
}
mtu_discovery_alarm_->Cancel();
// The write failed, but the writer is not blocked, so return true.
return true;
}
if (IsWriteError(result.status)) {
OnWriteError(result.error_code);
QUIC_LOG_FIRST_N(ERROR, 10)
<< ENDPOINT << "failed writing packet " << packet_number << " of "
<< encrypted_length << " bytes from " << self_address().host() << " to "
<< peer_address() << ", with error code " << result.error_code;
return false;
}
if (debug_visitor_ != nullptr) {
// Pass the write result to the visitor.
debug_visitor_->OnPacketSent(*packet, packet->original_packet_number,
packet->transmission_type, packet_send_time);
}
if (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA) {
if (!is_path_degrading_ && !path_degrading_alarm_->IsSet()) {
// This is the first retransmittable packet on the working path.
// Start the path degrading alarm to detect new path degrading.
SetPathDegradingAlarm();
}
// Update |time_of_first_packet_sent_after_receiving_| if this is the
// first packet sent after the last packet was received. If it were
// updated on every sent packet, then sending into a black hole might
// never timeout.
if (time_of_first_packet_sent_after_receiving_ <
time_of_last_received_packet_) {
time_of_first_packet_sent_after_receiving_ = packet_send_time;
}
}
MaybeSetMtuAlarm(packet_number);
QUIC_DVLOG(1) << ENDPOINT << "time we began writing last sent packet: "
<< packet_send_time.ToDebuggingValue();
if (EnforceAntiAmplificationLimit()) {
// Include bytes sent even if they are not in flight.
bytes_sent_before_address_validation_ += packet->encrypted_length;
}
const bool in_flight = sent_packet_manager_.OnPacketSent(
packet, packet->original_packet_number, packet_send_time,
packet->transmission_type, IsRetransmittable(*packet));
if (in_flight || !retransmission_alarm_->IsSet()) {
SetRetransmissionAlarm();
}
SetPingAlarm();
// The packet number length must be updated after OnPacketSent, because it
// may change the packet number length in packet.
packet_generator_.UpdatePacketNumberLength(
sent_packet_manager_.GetLeastUnacked(),
sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
stats_.bytes_sent += result.bytes_written;
++stats_.packets_sent;
if (packet->transmission_type != NOT_RETRANSMISSION) {
stats_.bytes_retransmitted += result.bytes_written;
++stats_.packets_retransmitted;
}
return true;
}
void QuicConnection::FlushPackets() {
if (!connected_) {
return;
}
if (!writer_->IsBatchMode()) {
return;
}
if (HandleWriteBlocked()) {
QUIC_DLOG(INFO) << ENDPOINT << "FlushPackets called while blocked.";
return;
}
WriteResult result = writer_->Flush();
if (HandleWriteBlocked()) {
DCHECK_EQ(WRITE_STATUS_BLOCKED, result.status)
<< "Unexpected flush result:" << result;
QUIC_DLOG(INFO) << ENDPOINT << "Write blocked in FlushPackets.";
return;
}
if (IsWriteError(result.status)) {
OnWriteError(result.error_code);
}
}
bool QuicConnection::IsMsgTooBig(const WriteResult& result) {
return (result.status == WRITE_STATUS_MSG_TOO_BIG) ||
(IsWriteError(result.status) && result.error_code == QUIC_EMSGSIZE);
}
bool QuicConnection::ShouldDiscardPacket(const SerializedPacket& packet) {
if (!connected_) {
QUIC_DLOG(INFO) << ENDPOINT
<< "Not sending packet as connection is disconnected.";
return true;
}
QuicPacketNumber packet_number = packet.packet_number;
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE &&
packet.encryption_level == ENCRYPTION_INITIAL) {
// Drop packets that are NULL encrypted since the peer won't accept them
// anymore.
QUIC_DLOG(INFO) << ENDPOINT
<< "Dropping NULL encrypted packet: " << packet_number
<< " since the connection is forward secure.";
return true;
}
return false;
}
void QuicConnection::OnWriteError(int error_code) {
if (write_error_occurred_) {
// A write error already occurred. The connection is being closed.
return;
}
write_error_occurred_ = true;
const std::string error_details = QuicStrCat(
"Write failed with error: ", error_code, " (", strerror(error_code), ")");
QUIC_LOG_FIRST_N(ERROR, 2) << ENDPOINT << error_details;
switch (error_code) {
case QUIC_EMSGSIZE:
CloseConnection(QUIC_PACKET_WRITE_ERROR, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
break;
default:
// We can't send an error as the socket is presumably borked.
if (VersionHasIetfInvariantHeader(transport_version())) {
QUIC_CODE_COUNT(quic_tear_down_local_connection_on_write_error_ietf);
} else {
QUIC_CODE_COUNT(
quic_tear_down_local_connection_on_write_error_non_ietf);
}
CloseConnection(QUIC_PACKET_WRITE_ERROR, error_details,
ConnectionCloseBehavior::SILENT_CLOSE);
}
}
char* QuicConnection::GetPacketBuffer() {
return writer_->GetNextWriteLocation(self_address().host(), peer_address());
}
void QuicConnection::OnSerializedPacket(SerializedPacket* serialized_packet) {
if (serialized_packet->encrypted_buffer == nullptr) {
// We failed to serialize the packet, so close the connection.
// Specify that the close is silent, that no packet be sent, so no infinite
// loop here.
// TODO(ianswett): This is actually an internal error, not an
// encryption failure.
if (VersionHasIetfInvariantHeader(transport_version())) {
QUIC_CODE_COUNT(
quic_tear_down_local_connection_on_serialized_packet_ietf);
} else {
QUIC_CODE_COUNT(
quic_tear_down_local_connection_on_serialized_packet_non_ietf);
}
CloseConnection(QUIC_ENCRYPTION_FAILURE,
"Serialized packet does not have an encrypted buffer.",
ConnectionCloseBehavior::SILENT_CLOSE);
return;
}
if (serialized_packet->retransmittable_frames.empty() &&
!serialized_packet->original_packet_number.IsInitialized()) {
// Increment consecutive_num_packets_with_no_retransmittable_frames_ if
// this packet is a new transmission with no retransmittable frames.
++consecutive_num_packets_with_no_retransmittable_frames_;
} else {
consecutive_num_packets_with_no_retransmittable_frames_ = 0;
}
SendOrQueuePacket(serialized_packet);
}
void QuicConnection::OnUnrecoverableError(QuicErrorCode error,
const std::string& error_details) {
// The packet creator or generator encountered an unrecoverable error: tear
// down local connection state immediately.
if (VersionHasIetfInvariantHeader(transport_version())) {
QUIC_CODE_COUNT(
quic_tear_down_local_connection_on_unrecoverable_error_ietf);
} else {
QUIC_CODE_COUNT(
quic_tear_down_local_connection_on_unrecoverable_error_non_ietf);
}
CloseConnection(error, error_details, ConnectionCloseBehavior::SILENT_CLOSE);
}
void QuicConnection::OnCongestionChange() {
visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
// Uses the connection's smoothed RTT. If zero, uses initial_rtt.
QuicTime::Delta rtt = sent_packet_manager_.GetRttStats()->smoothed_rtt();
if (rtt.IsZero()) {
rtt = sent_packet_manager_.GetRttStats()->initial_rtt();
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRttChanged(rtt);
}
}
void QuicConnection::OnPathMtuIncreased(QuicPacketLength packet_size) {
if (packet_size > max_packet_length()) {
const QuicByteCount old_max_packet_length = max_packet_length();
SetMaxPacketLength(packet_size);
if (mtu_discovery_v2_) {
mtu_discoverer_.OnMaxPacketLengthUpdated(old_max_packet_length,
max_packet_length());
}
}
}
void QuicConnection::OnHandshakeComplete() {
sent_packet_manager_.SetHandshakeConfirmed();
// This may have changed the retransmission timer, so re-arm it.
SetRetransmissionAlarm();
// The client should immediately ack the SHLO to confirm the handshake is
// complete with the server.
if (perspective_ == Perspective::IS_CLIENT && ack_frame_updated()) {
ack_alarm_->Update(clock_->ApproximateNow(), QuicTime::Delta::Zero());
}
}
void QuicConnection::SendOrQueuePacket(SerializedPacket* packet) {
// The caller of this function is responsible for checking CanWrite().
if (packet->encrypted_buffer == nullptr) {
QUIC_BUG << "packet.encrypted_buffer == nullptr in to SendOrQueuePacket";
return;
}
// If there are already queued packets, queue this one immediately to ensure
// it's written in sequence number order.
if (!queued_packets_.empty() || !WritePacket(packet)) {
if (!treat_queued_packets_as_sent_) {
// Take ownership of the underlying encrypted packet.
packet->encrypted_buffer = CopyBuffer(*packet);
queued_packets_.push_back(*packet);
packet->retransmittable_frames.clear();
}
}
ClearSerializedPacket(packet);
}
void QuicConnection::OnPingTimeout() {
if (!retransmission_alarm_->IsSet()) {
visitor_->SendPing();
}
}
void QuicConnection::SendAck() {
DCHECK(!SupportsMultiplePacketNumberSpaces());
QUIC_DVLOG(1) << ENDPOINT << "Sending an ACK proactively";
QuicFrames frames;
frames.push_back(GetUpdatedAckFrame());
if (!no_stop_waiting_frames_) {
QuicStopWaitingFrame stop_waiting;
PopulateStopWaitingFrame(&stop_waiting);
frames.push_back(QuicFrame(stop_waiting));
}
if (!packet_generator_.FlushAckFrame(frames)) {
return;
}
ResetAckStates();
if (consecutive_num_packets_with_no_retransmittable_frames_ <
max_consecutive_num_packets_with_no_retransmittable_frames_) {
return;
}
consecutive_num_packets_with_no_retransmittable_frames_ = 0;
if (packet_generator_.HasRetransmittableFrames() ||
visitor_->WillingAndAbleToWrite()) {
// There are pending retransmittable frames.
return;
}
visitor_->OnAckNeedsRetransmittableFrame();
}
void QuicConnection::OnPathDegradingTimeout() {
is_path_degrading_ = true;
visitor_->OnPathDegrading();
}
void QuicConnection::OnRetransmissionTimeout() {
DCHECK(!sent_packet_manager_.unacked_packets().empty() ||
(sent_packet_manager_.handshake_mode_disabled() &&
!sent_packet_manager_.handshake_confirmed()));
const QuicPacketNumber previous_created_packet_number =
packet_generator_.packet_number();
if (close_connection_after_five_rtos_ &&
sent_packet_manager_.GetConsecutiveRtoCount() >= 4) {
// Close on the 5th consecutive RTO, so after 4 previous RTOs have occurred.
CloseConnection(QUIC_TOO_MANY_RTOS, "5 consecutive retransmission timeouts",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (sent_packet_manager_.pto_enabled() && max_consecutive_ptos_ > 0 &&
sent_packet_manager_.GetConsecutivePtoCount() >= max_consecutive_ptos_) {
CloseConnection(QUIC_TOO_MANY_RTOS,
QuicStrCat(max_consecutive_ptos_ + 1,
"consecutive retransmission timeouts"),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
const auto retransmission_mode =
sent_packet_manager_.OnRetransmissionTimeout();
if (skip_packet_number_for_pto_ &&
retransmission_mode == QuicSentPacketManager::PTO_MODE &&
sent_packet_manager_.pending_timer_transmission_count() == 1) {
// Skip a packet number when a single PTO packet is sent to elicit an
// immediate ACK.
packet_generator_.SkipNPacketNumbers(
1, sent_packet_manager_.GetLeastUnacked(),
sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
}
WriteIfNotBlocked();
// A write failure can result in the connection being closed, don't attempt to
// write further packets, or to set alarms.
if (!connected_) {
return;
}
// In the PTO and TLP cases, the SentPacketManager gives the connection the
// opportunity to send new data before retransmitting.
if (sent_packet_manager_.pto_enabled()) {
sent_packet_manager_.MaybeSendProbePackets();
} else if (sent_packet_manager_.MaybeRetransmitTailLossProbe()) {
// Send the pending retransmission now that it's been queued.
WriteIfNotBlocked();
}
if (session_decides_what_to_write()) {
if (packet_generator_.packet_number() == previous_created_packet_number &&
(retransmission_mode == QuicSentPacketManager::TLP_MODE ||
retransmission_mode == QuicSentPacketManager::RTO_MODE ||
retransmission_mode == QuicSentPacketManager::PTO_MODE) &&
!visitor_->WillingAndAbleToWrite()) {
// Send PING if timer fires in RTO or PTO mode but there is no data to
// send.
// When TLP fires, either new data or tail loss probe should be sent.
// There is corner case where TLP fires after RTO because packets get
// acked. Two packets are marked RTO_RETRANSMITTED, but the first packet
// is retransmitted as two packets because of packet number length
// increases (please see QuicConnectionTest.RtoPacketAsTwo).
QUIC_DLOG_IF(WARNING,
retransmission_mode == QuicSentPacketManager::TLP_MODE &&
stats_.rto_count == 0)
<< "No packet gets sent when timer fires in TLP mode, sending PING";
DCHECK_LT(0u, sent_packet_manager_.pending_timer_transmission_count());
visitor_->SendPing();
}
if (retransmission_mode == QuicSentPacketManager::PTO_MODE) {
sent_packet_manager_.AdjustPendingTimerTransmissions();
}
if (retransmission_mode != QuicSentPacketManager::LOSS_MODE) {
// When timer fires in TLP or RTO mode, ensure 1) at least one packet is
// created, or there is data to send and available credit (such that
// packets will be sent eventually).
QUIC_BUG_IF(
packet_generator_.packet_number() == previous_created_packet_number &&
(!visitor_->WillingAndAbleToWrite() ||
sent_packet_manager_.pending_timer_transmission_count() == 0u))
<< "retransmission_mode: " << retransmission_mode
<< ", packet_number: " << packet_generator_.packet_number()
<< ", session has data to write: "
<< visitor_->WillingAndAbleToWrite()
<< ", writer is blocked: " << writer_->IsWriteBlocked()
<< ", pending_timer_transmission_count: "
<< sent_packet_manager_.pending_timer_transmission_count();
}
}
// Ensure the retransmission alarm is always set if there are unacked packets
// and nothing waiting to be sent.
// This happens if the loss algorithm invokes a timer based loss, but the
// packet doesn't need to be retransmitted.
if (!HasQueuedData() && !retransmission_alarm_->IsSet()) {
SetRetransmissionAlarm();
}
}
void QuicConnection::SetEncrypter(EncryptionLevel level,
std::unique_ptr<QuicEncrypter> encrypter) {
packet_generator_.SetEncrypter(level, std::move(encrypter));
}
void QuicConnection::SetDiversificationNonce(
const DiversificationNonce& nonce) {
DCHECK_EQ(Perspective::IS_SERVER, perspective_);
packet_generator_.SetDiversificationNonce(nonce);
}
void QuicConnection::SetDefaultEncryptionLevel(EncryptionLevel level) {
QUIC_DVLOG(1) << ENDPOINT << "Setting default encryption level from "
<< EncryptionLevelToString(encryption_level_) << " to "
<< EncryptionLevelToString(level);
if (level != encryption_level_ && packet_generator_.HasPendingFrames()) {
// Flush all queued frames when encryption level changes.
ScopedPacketFlusher flusher(this);
packet_generator_.FlushAllQueuedFrames();
}
encryption_level_ = level;
packet_generator_.set_encryption_level(level);
}
void QuicConnection::SetDecrypter(EncryptionLevel level,
std::unique_ptr<QuicDecrypter> decrypter) {
framer_.SetDecrypter(level, std::move(decrypter));
if (!undecryptable_packets_.empty() &&
!process_undecryptable_packets_alarm_->IsSet()) {
process_undecryptable_packets_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::SetAlternativeDecrypter(
EncryptionLevel level,
std::unique_ptr<QuicDecrypter> decrypter,
bool latch_once_used) {
framer_.SetAlternativeDecrypter(level, std::move(decrypter), latch_once_used);
if (!undecryptable_packets_.empty() &&
!process_undecryptable_packets_alarm_->IsSet()) {
process_undecryptable_packets_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::InstallDecrypter(
EncryptionLevel level,
std::unique_ptr<QuicDecrypter> decrypter) {
framer_.InstallDecrypter(level, std::move(decrypter));
if (!undecryptable_packets_.empty() &&
!process_undecryptable_packets_alarm_->IsSet()) {
process_undecryptable_packets_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::RemoveDecrypter(EncryptionLevel level) {
framer_.RemoveDecrypter(level);
}
const QuicDecrypter* QuicConnection::decrypter() const {
return framer_.decrypter();
}
const QuicDecrypter* QuicConnection::alternative_decrypter() const {
return framer_.alternative_decrypter();
}
void QuicConnection::QueueUndecryptablePacket(
const QuicEncryptedPacket& packet) {
for (const auto& saved_packet : undecryptable_packets_) {
if (packet.data() == saved_packet->data() &&
packet.length() == saved_packet->length()) {
QUIC_DVLOG(1) << ENDPOINT << "Not queueing known undecryptable packet";
return;
}
}
QUIC_DVLOG(1) << ENDPOINT << "Queueing undecryptable packet.";
undecryptable_packets_.push_back(packet.Clone());
}
void QuicConnection::MaybeProcessUndecryptablePackets() {
process_undecryptable_packets_alarm_->Cancel();
if (undecryptable_packets_.empty() ||
encryption_level_ == ENCRYPTION_INITIAL) {
return;
}
while (connected_ && !undecryptable_packets_.empty()) {
// Making sure there is no pending frames when processing next undecrypted
// packet because the queued ack frame may change.
packet_generator_.FlushAllQueuedFrames();
if (!connected_) {
return;
}
QUIC_DVLOG(1) << ENDPOINT << "Attempting to process undecryptable packet";
QuicEncryptedPacket* packet = undecryptable_packets_.front().get();
if (!framer_.ProcessPacket(*packet) &&
framer_.error() == QUIC_DECRYPTION_FAILURE) {
QUIC_DVLOG(1) << ENDPOINT << "Unable to process undecryptable packet...";
break;
}
QUIC_DVLOG(1) << ENDPOINT << "Processed undecryptable packet!";
++stats_.packets_processed;
undecryptable_packets_.pop_front();
}
// Once forward secure encryption is in use, there will be no
// new keys installed and hence any undecryptable packets will
// never be able to be decrypted.
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE) {
if (debug_visitor_ != nullptr) {
// TODO(rtenneti): perhaps more efficient to pass the number of
// undecryptable packets as the argument to OnUndecryptablePacket so that
// we just need to call OnUndecryptablePacket once?
for (size_t i = 0; i < undecryptable_packets_.size(); ++i) {
debug_visitor_->OnUndecryptablePacket();
}
}
undecryptable_packets_.clear();
}
}
void QuicConnection::QueueCoalescedPacket(const QuicEncryptedPacket& packet) {
QUIC_DVLOG(1) << ENDPOINT << "Queueing coalesced packet.";
coalesced_packets_.push_back(packet.Clone());
}
void QuicConnection::MaybeProcessCoalescedPackets() {
bool processed = false;
while (connected_ && !coalesced_packets_.empty()) {
// Making sure there are no pending frames when processing the next
// coalesced packet because the queued ack frame may change.
packet_generator_.FlushAllQueuedFrames();
if (!connected_) {
return;
}
std::unique_ptr<QuicEncryptedPacket> packet =
std::move(coalesced_packets_.front());
coalesced_packets_.pop_front();
QUIC_DVLOG(1) << ENDPOINT << "Processing coalesced packet";
if (framer_.ProcessPacket(*packet)) {
processed = true;
} else {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
}
}
if (processed) {
MaybeProcessUndecryptablePackets();
}
}
void QuicConnection::CloseConnection(
QuicErrorCode error,
const std::string& error_details,
ConnectionCloseBehavior connection_close_behavior) {
DCHECK(!error_details.empty());
if (!connected_) {
QUIC_DLOG(INFO) << "Connection is already closed.";
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Closing connection: " << connection_id()
<< ", with error: " << QuicErrorCodeToString(error) << " ("
<< error << "), and details: " << error_details;
if (connection_close_behavior != ConnectionCloseBehavior::SILENT_CLOSE) {
SendConnectionClosePacket(error, error_details);
}
TearDownLocalConnectionState(error, error_details,
ConnectionCloseSource::FROM_SELF);
}
void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
const std::string& details) {
if (!GetQuicReloadableFlag(quic_close_all_encryptions_levels)) {
QUIC_DLOG(INFO) << ENDPOINT << "Sending connection close packet.";
SetDefaultEncryptionLevel(GetConnectionCloseEncryptionLevel());
ClearQueuedPackets();
// If there was a packet write error, write the smallest close possible.
ScopedPacketFlusher flusher(this);
// When multiple packet number spaces is supported, an ACK frame will be
// bundled when connection is not write blocked.
if (!SupportsMultiplePacketNumberSpaces() &&
error != QUIC_PACKET_WRITE_ERROR &&
!GetUpdatedAckFrame().ack_frame->packets.Empty()) {
SendAck();
}
QuicConnectionCloseFrame* frame;
frame = new QuicConnectionCloseFrame(transport_version(), error, details,
framer_.current_received_frame_type());
packet_generator_.ConsumeRetransmittableControlFrame(QuicFrame(frame));
packet_generator_.FlushAllQueuedFrames();
ClearQueuedPackets();
return;
}
const EncryptionLevel current_encryption_level = encryption_level_;
ScopedPacketFlusher flusher(this);
QUIC_RELOADABLE_FLAG_COUNT(quic_close_all_encryptions_levels);
for (EncryptionLevel level :
{ENCRYPTION_INITIAL, ENCRYPTION_HANDSHAKE, ENCRYPTION_ZERO_RTT,
ENCRYPTION_FORWARD_SECURE}) {
if (!framer_.HasEncrypterOfEncryptionLevel(level)) {
continue;
}
QUIC_DLOG(INFO) << ENDPOINT << "Sending connection close packet at level: "
<< EncryptionLevelToString(level);
SetDefaultEncryptionLevel(level);
ClearQueuedPackets();
// If there was a packet write error, write the smallest close possible.
// When multiple packet number spaces are supported, an ACK frame will
// be bundled by the ScopedPacketFlusher. Otherwise, an ACK must be sent
// explicitly.
if (!SupportsMultiplePacketNumberSpaces() &&
error != QUIC_PACKET_WRITE_ERROR &&
!GetUpdatedAckFrame().ack_frame->packets.Empty()) {
SendAck();
}
auto* frame =
new QuicConnectionCloseFrame(transport_version(), error, details,
framer_.current_received_frame_type());
packet_generator_.ConsumeRetransmittableControlFrame(QuicFrame(frame));
packet_generator_.FlushAllQueuedFrames();
ClearQueuedPackets();
}
SetDefaultEncryptionLevel(current_encryption_level);
}
void QuicConnection::TearDownLocalConnectionState(
QuicErrorCode error,
const std::string& error_details,
ConnectionCloseSource source) {
QuicConnectionCloseFrame frame(transport_version(), error, error_details,
framer_.current_received_frame_type());
return TearDownLocalConnectionState(frame, source);
}
void QuicConnection::TearDownLocalConnectionState(
const QuicConnectionCloseFrame& frame,
ConnectionCloseSource source) {
if (!connected_) {
QUIC_DLOG(INFO) << "Connection is already closed.";
return;
}
// If we are using a batch writer, flush packets queued in it, if any.
FlushPackets();
connected_ = false;
DCHECK(visitor_ != nullptr);
visitor_->OnConnectionClosed(frame, source);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionClosed(frame, source);
}
// Cancel the alarms so they don't trigger any action now that the
// connection is closed.
CancelAllAlarms();
}
void QuicConnection::CancelAllAlarms() {
QUIC_DVLOG(1) << "Cancelling all QuicConnection alarms.";
ack_alarm_->Cancel();
ping_alarm_->Cancel();
retransmission_alarm_->Cancel();
send_alarm_->Cancel();
timeout_alarm_->Cancel();
mtu_discovery_alarm_->Cancel();
path_degrading_alarm_->Cancel();
process_undecryptable_packets_alarm_->Cancel();
}
QuicByteCount QuicConnection::max_packet_length() const {
return packet_generator_.GetCurrentMaxPacketLength();
}
void QuicConnection::SetMaxPacketLength(QuicByteCount length) {
long_term_mtu_ = length;
packet_generator_.SetMaxPacketLength(GetLimitedMaxPacketSize(length));
}
bool QuicConnection::HasQueuedData() const {
return pending_version_negotiation_packet_ || !queued_packets_.empty() ||
packet_generator_.HasPendingFrames() || !buffered_packets_.empty();
}
bool QuicConnection::CanWriteStreamData() {
// Don't write stream data if there are negotiation or queued data packets
// to send. Otherwise, continue and bundle as many frames as possible.
if (pending_version_negotiation_packet_ || !queued_packets_.empty() ||
!buffered_packets_.empty()) {
return false;
}
IsHandshake pending_handshake =
visitor_->HasPendingHandshake() ? IS_HANDSHAKE : NOT_HANDSHAKE;
// Sending queued packets may have caused the socket to become write blocked,
// or the congestion manager to prohibit sending. If we've sent everything
// we had queued and we're still not blocked, let the visitor know it can
// write more.
return ShouldGeneratePacket(HAS_RETRANSMITTABLE_DATA, pending_handshake);
}
void QuicConnection::SetNetworkTimeouts(QuicTime::Delta handshake_timeout,
QuicTime::Delta idle_timeout) {
QUIC_BUG_IF(idle_timeout > handshake_timeout)
<< "idle_timeout:" << idle_timeout.ToMilliseconds()
<< " handshake_timeout:" << handshake_timeout.ToMilliseconds();
// Adjust the idle timeout on client and server to prevent clients from
// sending requests to servers which have already closed the connection.
if (perspective_ == Perspective::IS_SERVER) {
idle_timeout = idle_timeout + QuicTime::Delta::FromSeconds(3);
} else if (idle_timeout > QuicTime::Delta::FromSeconds(1)) {
idle_timeout = idle_timeout - QuicTime::Delta::FromSeconds(1);
}
handshake_timeout_ = handshake_timeout;
idle_network_timeout_ = idle_timeout;
SetTimeoutAlarm();
}
void QuicConnection::CheckForTimeout() {
QuicTime now = clock_->ApproximateNow();
QuicTime time_of_last_packet =
std::max(time_of_last_received_packet_,
time_of_first_packet_sent_after_receiving_);
// |delta| can be < 0 as |now| is approximate time but |time_of_last_packet|
// is accurate time. However, this should not change the behavior of
// timeout handling.
QuicTime::Delta idle_duration = now - time_of_last_packet;
QUIC_DVLOG(1) << ENDPOINT << "last packet "
<< time_of_last_packet.ToDebuggingValue()
<< " now:" << now.ToDebuggingValue()
<< " idle_duration:" << idle_duration.ToMicroseconds()
<< " idle_network_timeout: "
<< idle_network_timeout_.ToMicroseconds();
if (idle_duration >= idle_network_timeout_) {
const std::string error_details = "No recent network activity.";
QUIC_DVLOG(1) << ENDPOINT << error_details;
if ((sent_packet_manager_.GetConsecutiveTlpCount() > 0 ||
sent_packet_manager_.GetConsecutiveRtoCount() > 0 ||
visitor_->ShouldKeepConnectionAlive())) {
CloseConnection(QUIC_NETWORK_IDLE_TIMEOUT, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
} else {
CloseConnection(QUIC_NETWORK_IDLE_TIMEOUT, error_details,
idle_timeout_connection_close_behavior_);
}
return;
}
if (!handshake_timeout_.IsInfinite()) {
QuicTime::Delta connected_duration = now - stats_.connection_creation_time;
QUIC_DVLOG(1) << ENDPOINT
<< "connection time: " << connected_duration.ToMicroseconds()
<< " handshake timeout: "
<< handshake_timeout_.ToMicroseconds();
if (connected_duration >= handshake_timeout_) {
const std::string error_details = "Handshake timeout expired.";
QUIC_DVLOG(1) << ENDPOINT << error_details;
CloseConnection(QUIC_HANDSHAKE_TIMEOUT, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
}
SetTimeoutAlarm();
}
void QuicConnection::SetTimeoutAlarm() {
QuicTime time_of_last_packet =
std::max(time_of_last_received_packet_,
time_of_first_packet_sent_after_receiving_);
QuicTime deadline = time_of_last_packet + idle_network_timeout_;
if (!handshake_timeout_.IsInfinite()) {
deadline = std::min(deadline,
stats_.connection_creation_time + handshake_timeout_);
}
timeout_alarm_->Update(deadline, QuicTime::Delta::Zero());
}
void QuicConnection::SetPingAlarm() {
if (perspective_ == Perspective::IS_SERVER) {
// Only clients send pings to avoid NATs from timing out.
return;
}
if (!visitor_->ShouldKeepConnectionAlive()) {
ping_alarm_->Cancel();
// Don't send a ping unless the application (ie: HTTP/3) says to, usually
// because it is expecting a response from the server.
return;
}
if (initial_retransmittable_on_wire_timeout_.IsInfinite() ||
sent_packet_manager_.HasInFlightPackets()) {
// Extend the ping alarm.
ping_alarm_->Update(clock_->ApproximateNow() + ping_timeout_,
QuicTime::Delta::FromSeconds(1));
return;
}
DCHECK_LT(initial_retransmittable_on_wire_timeout_, ping_timeout_);
QuicTime::Delta retransmittable_on_wire_timeout =
initial_retransmittable_on_wire_timeout_;
int max_aggressive_retransmittable_on_wire_ping_count =
GetQuicFlag(FLAGS_quic_max_aggressive_retransmittable_on_wire_ping_count);
DCHECK_LE(0, max_aggressive_retransmittable_on_wire_ping_count);
if (consecutive_retransmittable_on_wire_ping_count_ >
max_aggressive_retransmittable_on_wire_ping_count) {
// Exponentially back off the timeout if the number of consecutive
// retransmittable on wire pings has exceeds the allowance.
int shift = consecutive_retransmittable_on_wire_ping_count_ -
max_aggressive_retransmittable_on_wire_ping_count;
retransmittable_on_wire_timeout =
initial_retransmittable_on_wire_timeout_ * (1 << shift);
}
// If it's already set to an earlier time, then don't update it.
if (ping_alarm_->IsSet() &&
ping_alarm_->deadline() <
clock_->ApproximateNow() + retransmittable_on_wire_timeout) {
return;
}
if (retransmittable_on_wire_timeout < ping_timeout_) {
// Use a shorter timeout if there are open streams, but nothing on the wire.
ping_alarm_->Update(
clock_->ApproximateNow() + retransmittable_on_wire_timeout,
QuicTime::Delta::FromMilliseconds(1));
if (max_aggressive_retransmittable_on_wire_ping_count != 0) {
consecutive_retransmittable_on_wire_ping_count_++;
}
return;
}
ping_alarm_->Update(clock_->ApproximateNow() + ping_timeout_,
QuicTime::Delta::FromMilliseconds(1));
}
void QuicConnection::SetRetransmissionAlarm() {
if (packet_generator_.PacketFlusherAttached()) {
pending_retransmission_alarm_ = true;
return;
}
if (LimitedByAmplificationFactor()) {
// Do not set retransmission timer if connection is anti-amplification limit
// throttled. Otherwise, nothing can be sent when timer fires.
retransmission_alarm_->Cancel();
return;
}
retransmission_alarm_->Update(sent_packet_manager_.GetRetransmissionTime(),
QuicTime::Delta::FromMilliseconds(1));
}
void QuicConnection::SetPathDegradingAlarm() {
if (perspective_ == Perspective::IS_SERVER) {
return;
}
const QuicTime::Delta delay = sent_packet_manager_.GetPathDegradingDelay();
path_degrading_alarm_->Update(clock_->ApproximateNow() + delay,
QuicTime::Delta::FromMilliseconds(1));
}
void QuicConnection::MaybeSetMtuAlarm(QuicPacketNumber sent_packet_number) {
if (mtu_discovery_v2_) {
if (mtu_discovery_alarm_->IsSet() ||
!mtu_discoverer_.ShouldProbeMtu(sent_packet_number)) {
return;
}
mtu_discovery_alarm_->Set(clock_->ApproximateNow());
return;
}
// Do not set the alarm if the target size is less than the current size.
// This covers the case when |mtu_discovery_target_| is at its default value,
// zero.
if (mtu_discovery_target_ <= max_packet_length()) {
return;
}
if (mtu_probe_count_ >= kMtuDiscoveryAttempts) {
return;
}
if (mtu_discovery_alarm_->IsSet()) {
return;
}
if (sent_packet_number >= next_mtu_probe_at_) {
// Use an alarm to send the MTU probe to ensure that no ScopedPacketFlushers
// are active.
mtu_discovery_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::MaybeSetAckAlarmTo(QuicTime time) {
if (!ack_alarm_->IsSet() || ack_alarm_->deadline() > time) {
ack_alarm_->Update(time, QuicTime::Delta::Zero());
}
}
QuicConnection::ScopedPacketFlusher::ScopedPacketFlusher(
QuicConnection* connection)
: connection_(connection),
flush_and_set_pending_retransmission_alarm_on_delete_(false) {
if (connection_ == nullptr) {
return;
}
if (!connection_->packet_generator_.PacketFlusherAttached()) {
flush_and_set_pending_retransmission_alarm_on_delete_ = true;
connection->packet_generator_.AttachPacketFlusher();
}
}
QuicConnection::ScopedPacketFlusher::~ScopedPacketFlusher() {
if (connection_ == nullptr || !connection_->connected()) {
return;
}
if (flush_and_set_pending_retransmission_alarm_on_delete_) {
const QuicTime ack_timeout =
connection_->uber_received_packet_manager_.GetEarliestAckTimeout();
if (ack_timeout.IsInitialized()) {
if (ack_timeout <= connection_->clock_->ApproximateNow() &&
!connection_->CanWrite(NO_RETRANSMITTABLE_DATA)) {
// Cancel ACK alarm if connection is write blocked, and ACK will be
// sent when connection gets unblocked.
connection_->ack_alarm_->Cancel();
} else {
connection_->MaybeSetAckAlarmTo(ack_timeout);
}
}
if (connection_->ack_alarm_->IsSet() &&
connection_->ack_alarm_->deadline() <=
connection_->clock_->ApproximateNow()) {
// An ACK needs to be sent right now. This ACK did not get bundled
// because either there was no data to write or packets were marked as
// received after frames were queued in the generator.
if (connection_->send_alarm_->IsSet() &&
connection_->send_alarm_->deadline() <=
connection_->clock_->ApproximateNow()) {
// If send alarm will go off soon, let send alarm send the ACK.
connection_->ack_alarm_->Cancel();
} else if (connection_->SupportsMultiplePacketNumberSpaces()) {
connection_->SendAllPendingAcks();
} else {
connection_->SendAck();
}
}
connection_->packet_generator_.Flush();
connection_->FlushPackets();
if (connection_->session_decides_what_to_write()) {
// Reset transmission type.
connection_->SetTransmissionType(NOT_RETRANSMISSION);
}
// Once all transmissions are done, check if there is any outstanding data
// to send and notify the congestion controller if not.
//
// Note that this means that the application limited check will happen as
// soon as the last flusher gets destroyed, which is typically after a
// single stream write is finished. This means that if all the data from a
// single write goes through the connection, the application-limited signal
// will fire even if the caller does a write operation immediately after.
// There are two important approaches to remedy this situation:
// (1) Instantiate ScopedPacketFlusher before performing multiple subsequent
// writes, thus deferring this check until all writes are done.
// (2) Write data in chunks sufficiently large so that they cause the
// connection to be limited by the congestion control. Typically, this
// would mean writing chunks larger than the product of the current
// pacing rate and the pacer granularity. So, for instance, if the
// pacing rate of the connection is 1 Gbps, and the pacer granularity is
// 1 ms, the caller should send at least 125k bytes in order to not
// be marked as application-limited.
connection_->CheckIfApplicationLimited();
if (connection_->pending_retransmission_alarm_) {
connection_->SetRetransmissionAlarm();
connection_->pending_retransmission_alarm_ = false;
}
}
DCHECK_EQ(flush_and_set_pending_retransmission_alarm_on_delete_,
!connection_->packet_generator_.PacketFlusherAttached());
}
QuicConnection::BufferedPacket::BufferedPacket(
const SerializedPacket& packet,
const QuicSocketAddress& self_address,
const QuicSocketAddress& peer_address)
: encrypted_buffer(CopyBuffer(packet), packet.encrypted_length),
self_address(self_address),
peer_address(peer_address) {}
QuicConnection::BufferedPacket::~BufferedPacket() {
delete[] encrypted_buffer.data();
}
HasRetransmittableData QuicConnection::IsRetransmittable(
const SerializedPacket& packet) {
// Retransmitted packets retransmittable frames are owned by the unacked
// packet map, but are not present in the serialized packet.
if (packet.transmission_type != NOT_RETRANSMISSION ||
!packet.retransmittable_frames.empty()) {
return HAS_RETRANSMITTABLE_DATA;
} else {
return NO_RETRANSMITTABLE_DATA;
}
}
bool QuicConnection::IsTerminationPacket(const SerializedPacket& packet) {
if (packet.retransmittable_frames.empty()) {
return false;
}
for (const QuicFrame& frame : packet.retransmittable_frames) {
if (frame.type == CONNECTION_CLOSE_FRAME) {
return true;
}
}
return false;
}
void QuicConnection::SetMtuDiscoveryTarget(QuicByteCount target) {
if (mtu_discovery_v2_) {
mtu_discoverer_.Disable();
mtu_discoverer_.Enable(max_packet_length(),
GetLimitedMaxPacketSize(target));
} else {
mtu_discovery_target_ = GetLimitedMaxPacketSize(target);
}
}
QuicByteCount QuicConnection::GetLimitedMaxPacketSize(
QuicByteCount suggested_max_packet_size) {
if (!peer_address_.IsInitialized()) {
QUIC_BUG << "Attempted to use a connection without a valid peer address";
return suggested_max_packet_size;
}
const QuicByteCount writer_limit = writer_->GetMaxPacketSize(peer_address());
QuicByteCount max_packet_size = suggested_max_packet_size;
if (max_packet_size > writer_limit) {
max_packet_size = writer_limit;
}
if (max_packet_size > kMaxOutgoingPacketSize) {
max_packet_size = kMaxOutgoingPacketSize;
}
return max_packet_size;
}
void QuicConnection::SendMtuDiscoveryPacket(QuicByteCount target_mtu) {
// Currently, this limit is ensured by the caller.
DCHECK_EQ(target_mtu, GetLimitedMaxPacketSize(target_mtu));
// Send the probe.
packet_generator_.GenerateMtuDiscoveryPacket(target_mtu);
}
// TODO(zhongyi): change this method to generate a connectivity probing packet
// and let the caller to call writer to write the packet and handle write
// status.
bool QuicConnection::SendConnectivityProbingPacket(
QuicPacketWriter* probing_writer,
const QuicSocketAddress& peer_address) {
return SendGenericPathProbePacket(probing_writer, peer_address,
/* is_response= */ false);
}
void QuicConnection::SendConnectivityProbingResponsePacket(
const QuicSocketAddress& peer_address) {
SendGenericPathProbePacket(nullptr, peer_address,
/* is_response= */ true);
}
bool QuicConnection::SendGenericPathProbePacket(
QuicPacketWriter* probing_writer,
const QuicSocketAddress& peer_address,
bool is_response) {
DCHECK(peer_address.IsInitialized());
if (!connected_) {
QUIC_BUG << "Not sending connectivity probing packet as connection is "
<< "disconnected.";
return false;
}
if (perspective_ == Perspective::IS_SERVER && probing_writer == nullptr) {
// Server can use default packet writer to write packet.
probing_writer = writer_;
}
DCHECK(probing_writer);
if (probing_writer->IsWriteBlocked()) {
QUIC_DLOG(INFO)
<< ENDPOINT
<< "Writer blocked when sending connectivity probing packet.";
if (probing_writer == writer_) {
// Visitor should not be write blocked if the probing writer is not the
// default packet writer.
visitor_->OnWriteBlocked();
}
return true;
}
QUIC_DLOG(INFO) << ENDPOINT
<< "Sending path probe packet for connection_id = "
<< server_connection_id_;
OwningSerializedPacketPointer probing_packet;
if (!VersionHasIetfQuicFrames(transport_version())) {
// Non-IETF QUIC, generate a padded ping regardless of whether this is a
// request or a response.
probing_packet = packet_generator_.SerializeConnectivityProbingPacket();
} else {
if (is_response) {
// Respond using IETF QUIC PATH_RESPONSE frame
if (IsCurrentPacketConnectivityProbing()) {
// Pad the response if the request was a google connectivity probe
// (padded).
probing_packet =
packet_generator_.SerializePathResponseConnectivityProbingPacket(
received_path_challenge_payloads_, /* is_padded = */ true);
received_path_challenge_payloads_.clear();
} else {
// Do not pad the response if the path challenge was not a google
// connectivity probe.
probing_packet =
packet_generator_.SerializePathResponseConnectivityProbingPacket(
received_path_challenge_payloads_,
/* is_padded = */ false);
received_path_challenge_payloads_.clear();
}
} else {
// Request using IETF QUIC PATH_CHALLENGE frame
transmitted_connectivity_probe_payload_ =
std::make_unique<QuicPathFrameBuffer>();
probing_packet =
packet_generator_.SerializePathChallengeConnectivityProbingPacket(
transmitted_connectivity_probe_payload_.get());
if (!probing_packet) {
transmitted_connectivity_probe_payload_ = nullptr;
}
}
}
DCHECK_EQ(IsRetransmittable(*probing_packet), NO_RETRANSMITTABLE_DATA);
const QuicTime packet_send_time = clock_->Now();
QUIC_DVLOG(2) << ENDPOINT
<< "Sending path probe packet for server connection ID "
<< server_connection_id_ << std::endl
<< QuicTextUtils::HexDump(
QuicStringPiece(probing_packet->encrypted_buffer,
probing_packet->encrypted_length));
WriteResult result = probing_writer->WritePacket(
probing_packet->encrypted_buffer, probing_packet->encrypted_length,
self_address().host(), peer_address, per_packet_options_);
// If using a batch writer and the probing packet is buffered, flush it.
if (probing_writer->IsBatchMode() && result.status == WRITE_STATUS_OK &&
result.bytes_written == 0) {
result = probing_writer->Flush();
}
if (IsWriteError(result.status)) {
// Write error for any connectivity probe should not affect the connection
// as it is sent on a different path.
QUIC_DLOG(INFO) << ENDPOINT << "Write probing packet failed with error = "
<< result.error_code;
return false;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketSent(
*probing_packet, probing_packet->original_packet_number,
probing_packet->transmission_type, packet_send_time);
}
// Call OnPacketSent regardless of the write result.
sent_packet_manager_.OnPacketSent(
probing_packet.get(), probing_packet->original_packet_number,
packet_send_time, probing_packet->transmission_type,
NO_RETRANSMITTABLE_DATA);
if (IsWriteBlockedStatus(result.status)) {
if (probing_writer == writer_) {
// Visitor should not be write blocked if the probing writer is not the
// default packet writer.
visitor_->OnWriteBlocked();
}
if (result.status == WRITE_STATUS_BLOCKED_DATA_BUFFERED) {
QUIC_DLOG(INFO) << ENDPOINT << "Write probing packet blocked";
}
}
return true;
}
void QuicConnection::DiscoverMtu() {
DCHECK(!mtu_discovery_alarm_->IsSet());
if (mtu_discovery_v2_) {
const QuicPacketNumber largest_sent_packet =
sent_packet_manager_.GetLargestSentPacket();
if (mtu_discoverer_.ShouldProbeMtu(largest_sent_packet)) {
++mtu_probe_count_;
SendMtuDiscoveryPacket(
mtu_discoverer_.GetUpdatedMtuProbeSize(largest_sent_packet));
}
DCHECK(!mtu_discovery_alarm_->IsSet());
return;
}
// Check if the MTU has been already increased.
if (mtu_discovery_target_ <= max_packet_length()) {
return;
}
// Calculate the packet number of the next probe *before* sending the current
// one. Otherwise, when SendMtuDiscoveryPacket() is called,
// MaybeSetMtuAlarm() will not realize that the probe has been just sent, and
// will reschedule this probe again.
packets_between_mtu_probes_ *= 2;
next_mtu_probe_at_ = sent_packet_manager_.GetLargestSentPacket() +
packets_between_mtu_probes_ + 1;
++mtu_probe_count_;
QUIC_DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
SendMtuDiscoveryPacket(mtu_discovery_target_);
DCHECK(!mtu_discovery_alarm_->IsSet());
}
void QuicConnection::OnEffectivePeerMigrationValidated() {
if (active_effective_peer_migration_type_ == NO_CHANGE) {
QUIC_BUG << "No migration underway.";
return;
}
highest_packet_sent_before_effective_peer_migration_.Clear();
active_effective_peer_migration_type_ = NO_CHANGE;
}
void QuicConnection::StartEffectivePeerMigration(AddressChangeType type) {
// TODO(fayang): Currently, all peer address change type are allowed. Need to
// add a method ShouldAllowPeerAddressChange(PeerAddressChangeType type) to
// determine whether |type| is allowed.
if (type == NO_CHANGE) {
QUIC_BUG << "EffectivePeerMigration started without address change.";
return;
}
QUIC_DLOG(INFO) << ENDPOINT << "Effective peer's ip:port changed from "
<< effective_peer_address_.ToString() << " to "
<< GetEffectivePeerAddressFromCurrentPacket().ToString()
<< ", address change type is " << type
<< ", migrating connection.";
highest_packet_sent_before_effective_peer_migration_ =
sent_packet_manager_.GetLargestSentPacket();
effective_peer_address_ = GetEffectivePeerAddressFromCurrentPacket();
active_effective_peer_migration_type_ = type;
// TODO(wub): Move these calls to OnEffectivePeerMigrationValidated.
OnConnectionMigration(type);
}
void QuicConnection::OnConnectionMigration(AddressChangeType addr_change_type) {
visitor_->OnConnectionMigration(addr_change_type);
sent_packet_manager_.OnConnectionMigration(addr_change_type);
}
bool QuicConnection::IsCurrentPacketConnectivityProbing() const {
return is_current_packet_connectivity_probing_;
}
bool QuicConnection::ack_frame_updated() const {
return uber_received_packet_manager_.IsAckFrameUpdated();
}
QuicStringPiece QuicConnection::GetCurrentPacket() {
if (current_packet_data_ == nullptr) {
return QuicStringPiece();
}
return QuicStringPiece(current_packet_data_, last_size_);
}
bool QuicConnection::MaybeConsiderAsMemoryCorruption(
const QuicStreamFrame& frame) {
if (QuicUtils::IsCryptoStreamId(transport_version(), frame.stream_id) ||
last_decrypted_packet_level_ != ENCRYPTION_INITIAL) {
return false;
}
if (perspective_ == Perspective::IS_SERVER &&
frame.data_length >= sizeof(kCHLO) &&
strncmp(frame.data_buffer, reinterpret_cast<const char*>(&kCHLO),
sizeof(kCHLO)) == 0) {
return true;
}
if (perspective_ == Perspective::IS_CLIENT &&
frame.data_length >= sizeof(kREJ) &&
strncmp(frame.data_buffer, reinterpret_cast<const char*>(&kREJ),
sizeof(kREJ)) == 0) {
return true;
}
return false;
}
void QuicConnection::MaybeSendProbingRetransmissions() {
DCHECK(fill_up_link_during_probing_);
// Don't send probing retransmissions until the handshake has completed.
if (!sent_packet_manager_.handshake_confirmed() ||
sent_packet_manager().HasUnackedCryptoPackets()) {
return;
}
if (probing_retransmission_pending_) {
QUIC_BUG << "MaybeSendProbingRetransmissions is called while another call "
"to it is already in progress";
return;
}
probing_retransmission_pending_ = true;
SendProbingRetransmissions();
probing_retransmission_pending_ = false;
}
void QuicConnection::CheckIfApplicationLimited() {
if (session_decides_what_to_write() && probing_retransmission_pending_) {
return;
}
bool application_limited =
queued_packets_.empty() && buffered_packets_.empty() &&
!sent_packet_manager_.HasPendingRetransmissions() &&
!visitor_->WillingAndAbleToWrite();
if (!application_limited) {
return;
}
if (fill_up_link_during_probing_) {
MaybeSendProbingRetransmissions();
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
return;
}
}
sent_packet_manager_.OnApplicationLimited();
}
void QuicConnection::UpdatePacketContent(PacketContent type) {
if (current_packet_content_ == NOT_PADDED_PING) {
// We have already learned the current packet is not a connectivity
// probing packet. Peer migration should have already been started earlier
// if needed.
return;
}
if (type == NO_FRAMES_RECEIVED) {
return;
}
if (type == FIRST_FRAME_IS_PING) {
if (current_packet_content_ == NO_FRAMES_RECEIVED) {
current_packet_content_ = FIRST_FRAME_IS_PING;
return;
}
}
// In Google QUIC we look for a packet with just a PING and PADDING.
// For IETF QUIC, the packet must consist of just a PATH_CHALLENGE frame,
// followed by PADDING. If the condition is met, mark things as
// connectivity-probing, causing later processing to generate the correct
// response.
if (type == SECOND_FRAME_IS_PADDING &&
current_packet_content_ == FIRST_FRAME_IS_PING) {
current_packet_content_ = SECOND_FRAME_IS_PADDING;
if (perspective_ == Perspective::IS_SERVER) {
is_current_packet_connectivity_probing_ =
current_effective_peer_migration_type_ != NO_CHANGE;
} else {
is_current_packet_connectivity_probing_ =
(last_packet_source_address_ != peer_address_) ||
(last_packet_destination_address_ != self_address_);
}
return;
}
current_packet_content_ = NOT_PADDED_PING;
if (GetLargestReceivedPacket().IsInitialized() &&
last_header_.packet_number == GetLargestReceivedPacket()) {
direct_peer_address_ = last_packet_source_address_;
if (current_effective_peer_migration_type_ != NO_CHANGE) {
// Start effective peer migration immediately when the current packet is
// confirmed not a connectivity probing packet.
// TODO(fayang): When multiple packet number spaces is supported, only
// start peer migration for the application data.
StartEffectivePeerMigration(current_effective_peer_migration_type_);
}
}
current_effective_peer_migration_type_ = NO_CHANGE;
}
void QuicConnection::MaybeEnableSessionDecidesWhatToWrite() {
sent_packet_manager_.SetSessionDecideWhatToWrite(true);
if (version().SupportsAntiAmplificationLimit()) {
sent_packet_manager_.EnableIetfPtoAndLossDetection();
}
packet_generator_.SetCanSetTransmissionType(true);
}
void QuicConnection::PostProcessAfterAckFrame(bool send_stop_waiting,
bool acked_new_packet) {
if (no_stop_waiting_frames_) {
uber_received_packet_manager_.DontWaitForPacketsBefore(
last_decrypted_packet_level_,
SupportsMultiplePacketNumberSpaces()
? sent_packet_manager_.GetLargestPacketPeerKnowsIsAcked(
last_decrypted_packet_level_)
: sent_packet_manager_.largest_packet_peer_knows_is_acked());
}
// Always reset the retransmission alarm when an ack comes in, since we now
// have a better estimate of the current rtt than when it was set.
SetRetransmissionAlarm();
MaybeSetPathDegradingAlarm(acked_new_packet);
if (send_stop_waiting) {
++stop_waiting_count_;
} else {
stop_waiting_count_ = 0;
}
}
void QuicConnection::MaybeSetPathDegradingAlarm(bool acked_new_packet) {
if (!sent_packet_manager_.HasInFlightPackets()) {
// There are no retransmittable packets on the wire, so it's impossible to
// say if the connection has degraded.
path_degrading_alarm_->Cancel();
} else if (acked_new_packet) {
// A previously-unacked packet has been acked, which means forward progress
// has been made. Unset |is_path_degrading| if the path was considered as
// degrading previously. Set/update the path degrading alarm.
is_path_degrading_ = false;
SetPathDegradingAlarm();
}
}
void QuicConnection::SetSessionNotifier(
SessionNotifierInterface* session_notifier) {
sent_packet_manager_.SetSessionNotifier(session_notifier);
}
void QuicConnection::SetDataProducer(
QuicStreamFrameDataProducer* data_producer) {
framer_.set_data_producer(data_producer);
}
void QuicConnection::SetTransmissionType(TransmissionType type) {
packet_generator_.SetTransmissionType(type);
}
bool QuicConnection::session_decides_what_to_write() const {
return sent_packet_manager_.session_decides_what_to_write();
}
void QuicConnection::UpdateReleaseTimeIntoFuture() {
DCHECK(supports_release_time_);
release_time_into_future_ = std::max(
QuicTime::Delta::FromMilliseconds(kMinReleaseTimeIntoFutureMs),
std::min(
QuicTime::Delta::FromMilliseconds(
GetQuicFlag(FLAGS_quic_max_pace_time_into_future_ms)),
sent_packet_manager_.GetRttStats()->SmoothedOrInitialRtt() *
GetQuicFlag(FLAGS_quic_pace_time_into_future_srtt_fraction)));
}
void QuicConnection::ResetAckStates() {
ack_alarm_->Cancel();
stop_waiting_count_ = 0;
uber_received_packet_manager_.ResetAckStates(encryption_level_);
}
MessageStatus QuicConnection::SendMessage(QuicMessageId message_id,
QuicMemSliceSpan message) {
if (!VersionSupportsMessageFrames(transport_version())) {
QUIC_BUG << "MESSAGE frame is not supported for version "
<< transport_version();
return MESSAGE_STATUS_UNSUPPORTED;
}
if (message.total_length() > GetCurrentLargestMessagePayload()) {
return MESSAGE_STATUS_TOO_LARGE;
}
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
return MESSAGE_STATUS_BLOCKED;
}
ScopedPacketFlusher flusher(this);
return packet_generator_.AddMessageFrame(message_id, message);
}
QuicPacketLength QuicConnection::GetCurrentLargestMessagePayload() const {
return packet_generator_.GetCurrentLargestMessagePayload();
}
QuicPacketLength QuicConnection::GetGuaranteedLargestMessagePayload() const {
return packet_generator_.GetGuaranteedLargestMessagePayload();
}
uint32_t QuicConnection::cipher_id() const {
if (version().KnowsWhichDecrypterToUse()) {
return framer_.GetDecrypter(last_decrypted_packet_level_)->cipher_id();
}
return framer_.decrypter()->cipher_id();
}
EncryptionLevel QuicConnection::GetConnectionCloseEncryptionLevel() const {
if (perspective_ == Perspective::IS_CLIENT) {
return encryption_level_;
}
if (sent_packet_manager_.handshake_confirmed()) {
// A forward secure packet has been received.
QUIC_BUG_IF(encryption_level_ != ENCRYPTION_FORWARD_SECURE)
<< ENDPOINT << "Unexpected connection close encryption level "
<< EncryptionLevelToString(encryption_level_);
return ENCRYPTION_FORWARD_SECURE;
}
if (framer_.HasEncrypterOfEncryptionLevel(ENCRYPTION_ZERO_RTT)) {
if (encryption_level_ != ENCRYPTION_ZERO_RTT) {
if (VersionHasIetfInvariantHeader(transport_version())) {
QUIC_CODE_COUNT(quic_wrong_encryption_level_connection_close_ietf);
} else {
QUIC_CODE_COUNT(quic_wrong_encryption_level_connection_close);
}
}
return ENCRYPTION_ZERO_RTT;
}
return ENCRYPTION_INITIAL;
}
void QuicConnection::SendAllPendingAcks() {
DCHECK(SupportsMultiplePacketNumberSpaces());
QUIC_DVLOG(1) << ENDPOINT << "Trying to send all pending ACKs";
ack_alarm_->Cancel();
// Latches current encryption level.
const EncryptionLevel current_encryption_level = encryption_level_;
for (int8_t i = INITIAL_DATA; i <= APPLICATION_DATA; ++i) {
const QuicTime ack_timeout = uber_received_packet_manager_.GetAckTimeout(
static_cast<PacketNumberSpace>(i));
if (!ack_timeout.IsInitialized() ||
ack_timeout > clock_->ApproximateNow()) {
continue;
}
if (!framer_.HasEncrypterOfEncryptionLevel(
QuicUtils::GetEncryptionLevel(static_cast<PacketNumberSpace>(i)))) {
QUIC_BUG << ENDPOINT << "Cannot send ACKs for packet number space "
<< PacketNumberSpaceToString(static_cast<PacketNumberSpace>(i))
<< " without corresponding encrypter";
continue;
}
QUIC_DVLOG(1) << ENDPOINT << "Sending ACK of packet number space "
<< PacketNumberSpaceToString(
static_cast<PacketNumberSpace>(i));
// Switch to the appropriate encryption level.
SetDefaultEncryptionLevel(
QuicUtils::GetEncryptionLevel(static_cast<PacketNumberSpace>(i)));
QuicFrames frames;
frames.push_back(uber_received_packet_manager_.GetUpdatedAckFrame(
static_cast<PacketNumberSpace>(i), clock_->ApproximateNow()));
const bool flushed = packet_generator_.FlushAckFrame(frames);
if (!flushed) {
// Connection is write blocked.
QUIC_BUG_IF(!writer_->IsWriteBlocked())
<< "Writer not blocked, but ACK not flushed for packet space:" << i;
break;
}
ResetAckStates();
}
// Restores encryption level.
SetDefaultEncryptionLevel(current_encryption_level);
const QuicTime timeout =
uber_received_packet_manager_.GetEarliestAckTimeout();
if (timeout.IsInitialized()) {
// If there are ACKs pending, re-arm ack alarm.
ack_alarm_->Set(timeout);
}
// Only try to bundle retransmittable data with ACK frame if default
// encryption level is forward secure.
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE ||
consecutive_num_packets_with_no_retransmittable_frames_ <
max_consecutive_num_packets_with_no_retransmittable_frames_) {
return;
}
consecutive_num_packets_with_no_retransmittable_frames_ = 0;
if (packet_generator_.HasRetransmittableFrames() ||
visitor_->WillingAndAbleToWrite()) {
// There are pending retransmittable frames.
return;
}
visitor_->OnAckNeedsRetransmittableFrame();
}
void QuicConnection::MaybeEnableMultiplePacketNumberSpacesSupport() {
if (version().handshake_protocol != PROTOCOL_TLS1_3) {
return;
}
QUIC_DVLOG(1) << ENDPOINT << "connection " << connection_id()
<< " supports multiple packet number spaces";
framer_.EnableMultiplePacketNumberSpacesSupport();
sent_packet_manager_.EnableMultiplePacketNumberSpacesSupport();
uber_received_packet_manager_.EnableMultiplePacketNumberSpacesSupport();
}
bool QuicConnection::SupportsMultiplePacketNumberSpaces() const {
return sent_packet_manager_.supports_multiple_packet_number_spaces();
}
void QuicConnection::SetLargestReceivedPacketWithAck(
QuicPacketNumber new_value) {
if (SupportsMultiplePacketNumberSpaces()) {
largest_seen_packets_with_ack_[QuicUtils::GetPacketNumberSpace(
last_decrypted_packet_level_)] = new_value;
} else {
largest_seen_packet_with_ack_ = new_value;
}
}
QuicPacketNumber QuicConnection::GetLargestReceivedPacketWithAck() const {
if (SupportsMultiplePacketNumberSpaces()) {
return largest_seen_packets_with_ack_[QuicUtils::GetPacketNumberSpace(
last_decrypted_packet_level_)];
}
return largest_seen_packet_with_ack_;
}
QuicPacketNumber QuicConnection::GetLargestSentPacket() const {
if (SupportsMultiplePacketNumberSpaces()) {
return sent_packet_manager_.GetLargestSentPacket(
last_decrypted_packet_level_);
}
return sent_packet_manager_.GetLargestSentPacket();
}
QuicPacketNumber QuicConnection::GetLargestAckedPacket() const {
if (SupportsMultiplePacketNumberSpaces()) {
return sent_packet_manager_.GetLargestAckedPacket(
last_decrypted_packet_level_);
}
return sent_packet_manager_.GetLargestObserved();
}
QuicPacketNumber QuicConnection::GetLargestReceivedPacket() const {
return uber_received_packet_manager_.GetLargestObserved(
last_decrypted_packet_level_);
}
bool QuicConnection::EnforceAntiAmplificationLimit() const {
return version().SupportsAntiAmplificationLimit() &&
perspective_ == Perspective::IS_SERVER && !address_validated_;
}
bool QuicConnection::LimitedByAmplificationFactor() const {
return EnforceAntiAmplificationLimit() &&
bytes_sent_before_address_validation_ >=
GetQuicFlag(FLAGS_quic_anti_amplification_factor) *
bytes_received_before_address_validation_;
}
QuicConnection::SerializedPacketFate QuicConnection::DeterminePacketFate() {
if (treat_queued_packets_as_sent_ &&
(!buffered_packets_.empty() || HandleWriteBlocked())) {
return BUFFER;
}
return SEND_TO_WRITER;
}
size_t QuicConnection::min_received_before_ack_decimation() const {
return uber_received_packet_manager_.min_received_before_ack_decimation();
}
void QuicConnection::set_min_received_before_ack_decimation(size_t new_value) {
uber_received_packet_manager_.set_min_received_before_ack_decimation(
new_value);
}
size_t QuicConnection::ack_frequency_before_ack_decimation() const {
return uber_received_packet_manager_.ack_frequency_before_ack_decimation();
}
void QuicConnection::set_ack_frequency_before_ack_decimation(size_t new_value) {
DCHECK_GT(new_value, 0u);
uber_received_packet_manager_.set_ack_frequency_before_ack_decimation(
new_value);
}
const QuicAckFrame& QuicConnection::ack_frame() const {
if (SupportsMultiplePacketNumberSpaces()) {
return uber_received_packet_manager_.GetAckFrame(
QuicUtils::GetPacketNumberSpace(last_decrypted_packet_level_));
}
return uber_received_packet_manager_.ack_frame();
}
void QuicConnection::set_client_connection_id(
QuicConnectionId client_connection_id) {
if (!version().SupportsClientConnectionIds()) {
QUIC_BUG_IF(!client_connection_id.IsEmpty())
<< ENDPOINT << "Attempted to use client connection ID "
<< client_connection_id << " with unsupported version " << version();
return;
}
client_connection_id_ = client_connection_id;
client_connection_id_is_set_ = true;
QUIC_DLOG(INFO) << ENDPOINT << "setting client connection ID to "
<< client_connection_id_
<< " for connection with server connection ID "
<< server_connection_id_;
packet_generator_.SetClientConnectionId(client_connection_id_);
framer_.SetExpectedClientConnectionIdLength(client_connection_id_.length());
}
#undef ENDPOINT // undef for jumbo builds
} // namespace quic