blob: 1388cf6250d4b72e1e1778b26f5907f90935475c [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/quic/quic_connection.h"
#include <string.h>
#include <sys/types.h>
#include <algorithm>
#include <iterator>
#include <limits>
#include <memory>
#include <set>
#include <utility>
#include "base/debug/stack_trace.h"
#include "base/format_macros.h"
#include "base/logging.h"
#include "base/memory/ref_counted.h"
#include "base/profiler/scoped_tracker.h"
#include "base/stl_util.h"
#include "base/strings/stringprintf.h"
#include "net/base/net_errors.h"
#include "net/quic/crypto/crypto_protocol.h"
#include "net/quic/crypto/quic_decrypter.h"
#include "net/quic/crypto/quic_encrypter.h"
#include "net/quic/proto/cached_network_parameters.pb.h"
#include "net/quic/quic_bandwidth.h"
#include "net/quic/quic_config.h"
#include "net/quic/quic_fec_group.h"
#include "net/quic/quic_flags.h"
#include "net/quic/quic_packet_generator.h"
#include "net/quic/quic_utils.h"
using base::StringPiece;
using base::StringPrintf;
using base::hash_map;
using base::hash_set;
using std::list;
using std::make_pair;
using std::max;
using std::min;
using std::numeric_limits;
using std::set;
using std::string;
using std::vector;
namespace net {
class QuicDecrypter;
class QuicEncrypter;
namespace {
// The largest gap in packets we'll accept without closing the connection.
// This will likely have to be tuned.
const QuicPacketSequenceNumber kMaxPacketGap = 5000;
// Limit the number of FEC groups to two. If we get enough out of order packets
// that this becomes limiting, we can revisit.
const size_t kMaxFecGroups = 2;
// Maximum number of acks received before sending an ack in response.
const QuicPacketCount kMaxPacketsReceivedBeforeAckSend = 20;
bool Near(QuicPacketSequenceNumber a, QuicPacketSequenceNumber b) {
QuicPacketSequenceNumber delta = (a > b) ? a - b : b - a;
return delta <= kMaxPacketGap;
}
// An alarm that is scheduled to send an ack if a timeout occurs.
class AckAlarm : public QuicAlarm::Delegate {
public:
explicit AckAlarm(QuicConnection* connection)
: connection_(connection) {
}
QuicTime OnAlarm() override {
connection_->SendAck();
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(AckAlarm);
};
// 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 RetransmissionAlarm : public QuicAlarm::Delegate {
public:
explicit RetransmissionAlarm(QuicConnection* connection)
: connection_(connection) {
}
QuicTime OnAlarm() override {
connection_->OnRetransmissionTimeout();
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(RetransmissionAlarm);
};
// An alarm that is scheduled when the SentPacketManager requires a delay
// before sending packets and fires when the packet may be sent.
class SendAlarm : public QuicAlarm::Delegate {
public:
explicit SendAlarm(QuicConnection* connection)
: connection_(connection) {
}
QuicTime OnAlarm() override {
connection_->WriteIfNotBlocked();
// Never reschedule the alarm, since CanWrite does that.
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(SendAlarm);
};
class TimeoutAlarm : public QuicAlarm::Delegate {
public:
explicit TimeoutAlarm(QuicConnection* connection)
: connection_(connection) {
}
QuicTime OnAlarm() override {
connection_->CheckForTimeout();
// Never reschedule the alarm, since CheckForTimeout does that.
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(TimeoutAlarm);
};
class PingAlarm : public QuicAlarm::Delegate {
public:
explicit PingAlarm(QuicConnection* connection)
: connection_(connection) {
}
QuicTime OnAlarm() override {
connection_->SendPing();
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(PingAlarm);
};
class MtuDiscoveryAlarm : public QuicAlarm::Delegate {
public:
explicit MtuDiscoveryAlarm(QuicConnection* connection)
: connection_(connection) {}
QuicTime OnAlarm() override {
connection_->DiscoverMtu();
// DiscoverMtu() handles rescheduling the alarm by itself.
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
DISALLOW_COPY_AND_ASSIGN(MtuDiscoveryAlarm);
};
// This alarm may be scheduled when an FEC protected packet is sent out.
class FecAlarm : public QuicAlarm::Delegate {
public:
explicit FecAlarm(QuicPacketGenerator* packet_generator)
: packet_generator_(packet_generator) {}
QuicTime OnAlarm() override {
packet_generator_->OnFecTimeout();
return QuicTime::Zero();
}
private:
QuicPacketGenerator* packet_generator_;
DISALLOW_COPY_AND_ASSIGN(FecAlarm);
};
// Listens for acks of MTU discovery packets and raises the maximum packet size
// of the connection if the probe succeeds.
class MtuDiscoveryAckListener : public QuicAckNotifier::DelegateInterface {
public:
MtuDiscoveryAckListener(QuicConnection* connection, QuicByteCount probe_size)
: connection_(connection), probe_size_(probe_size) {}
void OnAckNotification(int /*num_retransmittable_packets*/,
int /*num_retransmittable_bytes*/,
QuicTime::Delta /*delta_largest_observed*/) override {
// Since the probe was successful, increase the maximum packet size to that.
if (probe_size_ > connection_->max_packet_length()) {
connection_->set_max_packet_length(probe_size_);
}
}
protected:
// MtuDiscoveryAckListener is ref counted.
~MtuDiscoveryAckListener() override {}
private:
QuicConnection* connection_;
QuicByteCount probe_size_;
DISALLOW_COPY_AND_ASSIGN(MtuDiscoveryAckListener);
};
} // namespace
QuicConnection::QueuedPacket::QueuedPacket(SerializedPacket packet,
EncryptionLevel level)
: serialized_packet(packet),
encryption_level(level),
transmission_type(NOT_RETRANSMISSION),
original_sequence_number(0) {
}
QuicConnection::QueuedPacket::QueuedPacket(
SerializedPacket packet,
EncryptionLevel level,
TransmissionType transmission_type,
QuicPacketSequenceNumber original_sequence_number)
: serialized_packet(packet),
encryption_level(level),
transmission_type(transmission_type),
original_sequence_number(original_sequence_number) {
}
#define ENDPOINT \
(perspective_ == Perspective::IS_SERVER ? "Server: " : "Client: ")
QuicConnection::QuicConnection(QuicConnectionId connection_id,
IPEndPoint address,
QuicConnectionHelperInterface* helper,
const PacketWriterFactory& writer_factory,
bool owns_writer,
Perspective perspective,
bool is_secure,
const QuicVersionVector& supported_versions)
: framer_(supported_versions,
helper->GetClock()->ApproximateNow(),
perspective),
helper_(helper),
writer_(writer_factory.Create(this)),
owns_writer_(owns_writer),
encryption_level_(ENCRYPTION_NONE),
has_forward_secure_encrypter_(false),
first_required_forward_secure_packet_(0),
clock_(helper->GetClock()),
random_generator_(helper->GetRandomGenerator()),
connection_id_(connection_id),
peer_address_(address),
migrating_peer_port_(0),
last_packet_decrypted_(false),
last_packet_revived_(false),
last_size_(0),
last_decrypted_packet_level_(ENCRYPTION_NONE),
should_last_packet_instigate_acks_(false),
largest_seen_packet_with_ack_(0),
largest_seen_packet_with_stop_waiting_(0),
max_undecryptable_packets_(0),
pending_version_negotiation_packet_(false),
silent_close_enabled_(false),
received_packet_manager_(&stats_),
ack_queued_(false),
num_packets_received_since_last_ack_sent_(0),
stop_waiting_count_(0),
delay_setting_retransmission_alarm_(false),
pending_retransmission_alarm_(false),
ack_alarm_(helper->CreateAlarm(new AckAlarm(this))),
retransmission_alarm_(helper->CreateAlarm(new RetransmissionAlarm(this))),
send_alarm_(helper->CreateAlarm(new SendAlarm(this))),
resume_writes_alarm_(helper->CreateAlarm(new SendAlarm(this))),
timeout_alarm_(helper->CreateAlarm(new TimeoutAlarm(this))),
ping_alarm_(helper->CreateAlarm(new PingAlarm(this))),
mtu_discovery_alarm_(helper->CreateAlarm(new MtuDiscoveryAlarm(this))),
visitor_(nullptr),
debug_visitor_(nullptr),
packet_generator_(connection_id_, &framer_, random_generator_, this),
fec_alarm_(helper->CreateAlarm(new FecAlarm(&packet_generator_))),
idle_network_timeout_(QuicTime::Delta::Infinite()),
overall_connection_timeout_(QuicTime::Delta::Infinite()),
time_of_last_received_packet_(clock_->ApproximateNow()),
time_of_last_sent_new_packet_(clock_->ApproximateNow()),
sequence_number_of_last_sent_packet_(0),
sent_packet_manager_(
perspective,
clock_,
&stats_,
FLAGS_quic_use_bbr_congestion_control ? kBBR : kCubic,
FLAGS_quic_use_time_loss_detection ? kTime : kNack,
is_secure),
version_negotiation_state_(START_NEGOTIATION),
perspective_(perspective),
connected_(true),
peer_ip_changed_(false),
peer_port_changed_(false),
self_ip_changed_(false),
self_port_changed_(false),
can_truncate_connection_ids_(true),
is_secure_(is_secure),
mtu_discovery_target_(0),
mtu_probe_count_(0),
packets_between_mtu_probes_(kPacketsBetweenMtuProbesBase),
next_mtu_probe_at_(kPacketsBetweenMtuProbesBase),
largest_received_packet_size_(0) {
DVLOG(1) << ENDPOINT << "Created connection with connection_id: "
<< connection_id;
framer_.set_visitor(this);
framer_.set_received_entropy_calculator(&received_packet_manager_);
stats_.connection_creation_time = clock_->ApproximateNow();
sent_packet_manager_.set_network_change_visitor(this);
if (perspective_ == Perspective::IS_SERVER) {
set_max_packet_length(kDefaultServerMaxPacketSize);
}
}
QuicConnection::~QuicConnection() {
if (owns_writer_) {
delete writer_;
}
STLDeleteElements(&undecryptable_packets_);
STLDeleteValues(&group_map_);
for (QueuedPacketList::iterator it = queued_packets_.begin();
it != queued_packets_.end(); ++it) {
delete it->serialized_packet.retransmittable_frames;
delete it->serialized_packet.packet;
}
}
void QuicConnection::SetFromConfig(const QuicConfig& config) {
if (config.negotiated()) {
SetNetworkTimeouts(QuicTime::Delta::Infinite(),
config.IdleConnectionStateLifetime());
if (config.SilentClose()) {
silent_close_enabled_ = true;
}
} 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_.SetConnectionIdLength(
config.ReceivedBytesForConnectionId());
}
max_undecryptable_packets_ = config.max_undecryptable_packets();
if (FLAGS_quic_send_fec_packet_only_on_fec_alarm &&
config.HasClientSentConnectionOption(kFSPA, perspective_)) {
packet_generator_.set_fec_send_policy(FecSendPolicy::FEC_ALARM_TRIGGER);
}
if (config.HasClientSentConnectionOption(kMTUH, perspective_)) {
mtu_discovery_target_ = kMtuDiscoveryTargetPacketSizeHigh;
}
if (config.HasClientSentConnectionOption(kMTUL, perspective_)) {
mtu_discovery_target_ = kMtuDiscoveryTargetPacketSizeLow;
}
}
void QuicConnection::OnSendConnectionState(
const CachedNetworkParameters& cached_network_params) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSendConnectionState(cached_network_params);
}
}
void QuicConnection::ResumeConnectionState(
const CachedNetworkParameters& cached_network_params,
bool max_bandwidth_resumption) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnResumeConnectionState(cached_network_params);
}
sent_packet_manager_.ResumeConnectionState(cached_network_params,
max_bandwidth_resumption);
}
void QuicConnection::SetNumOpenStreams(size_t num_streams) {
sent_packet_manager_.SetNumOpenStreams(num_streams);
}
bool QuicConnection::SelectMutualVersion(
const QuicVersionVector& 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 QuicVersionVector& supported_versions = framer_.supported_versions();
for (size_t i = 0; i < supported_versions.size(); ++i) {
const QuicVersion& version = supported_versions[i];
if (std::find(available_versions.begin(), available_versions.end(),
version) != available_versions.end()) {
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;
}
SendConnectionCloseWithDetails(framer->error(), framer->detailed_error());
}
void QuicConnection::MaybeSetFecAlarm(
QuicPacketSequenceNumber sequence_number) {
if (fec_alarm_->IsSet()) {
return;
}
QuicTime::Delta timeout = packet_generator_.GetFecTimeout(sequence_number);
if (!timeout.IsInfinite()) {
fec_alarm_->Set(clock_->ApproximateNow().Add(timeout));
}
}
void QuicConnection::OnPacket() {
DCHECK(last_stream_frames_.empty() &&
last_ack_frames_.empty() &&
last_stop_waiting_frames_.empty() &&
last_rst_frames_.empty() &&
last_goaway_frames_.empty() &&
last_window_update_frames_.empty() &&
last_blocked_frames_.empty() &&
last_ping_frames_.empty() &&
last_close_frames_.empty());
last_packet_decrypted_ = false;
last_packet_revived_ = 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(connection_id_, packet.public_header.connection_id);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPublicResetPacket(packet);
}
CloseConnection(QUIC_PUBLIC_RESET, true);
DVLOG(1) << ENDPOINT << "Connection " << connection_id()
<< " closed via QUIC_PUBLIC_RESET from peer.";
}
bool QuicConnection::OnProtocolVersionMismatch(QuicVersion received_version) {
DVLOG(1) << ENDPOINT << "Received packet with mismatched version "
<< received_version;
// TODO(satyamshekhar): Implement no server state in this mode.
if (perspective_ == Perspective::IS_CLIENT) {
LOG(DFATAL) << ENDPOINT << "Framer called OnProtocolVersionMismatch. "
<< "Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return false;
}
DCHECK_NE(version(), received_version);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnProtocolVersionMismatch(received_version);
}
switch (version_negotiation_state_) {
case START_NEGOTIATION:
if (!framer_.IsSupportedVersion(received_version)) {
SendVersionNegotiationPacket();
version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
return false;
}
break;
case NEGOTIATION_IN_PROGRESS:
if (!framer_.IsSupportedVersion(received_version)) {
SendVersionNegotiationPacket();
return false;
}
break;
case NEGOTIATED_VERSION:
// Might be old packets that were sent by the client before the version
// was negotiated. Drop these.
return false;
default:
DCHECK(false);
}
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(received_version);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(received_version);
}
DVLOG(1) << ENDPOINT << "version negotiated " << received_version;
// Store the new version.
framer_.set_version(received_version);
// TODO(satyamshekhar): Store the sequence number of this packet and close the
// connection if we ever received a packet with incorrect version and whose
// sequence number is greater.
return true;
}
// 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(connection_id_, packet.connection_id);
if (perspective_ == Perspective::IS_SERVER) {
LOG(DFATAL) << ENDPOINT << "Framer parsed VersionNegotiationPacket."
<< " Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnVersionNegotiationPacket(packet);
}
if (version_negotiation_state_ != START_NEGOTIATION) {
// Possibly a duplicate version negotiation packet.
return;
}
if (std::find(packet.versions.begin(),
packet.versions.end(), version()) !=
packet.versions.end()) {
DLOG(WARNING) << ENDPOINT << "The server already supports our version. "
<< "It should have accepted our connection.";
// Just drop the connection.
CloseConnection(QUIC_INVALID_VERSION_NEGOTIATION_PACKET, false);
return;
}
if (!SelectMutualVersion(packet.versions)) {
SendConnectionCloseWithDetails(QUIC_INVALID_VERSION,
"no common version found");
return;
}
DVLOG(1) << ENDPOINT
<< "Negotiated version: " << QuicVersionToString(version());
server_supported_versions_ = packet.versions;
version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
RetransmitUnackedPackets(ALL_UNACKED_RETRANSMISSION);
}
void QuicConnection::OnRevivedPacket() {
}
bool QuicConnection::OnUnauthenticatedPublicHeader(
const QuicPacketPublicHeader& header) {
if (header.connection_id == connection_id_) {
return true;
}
++stats_.packets_dropped;
DVLOG(1) << ENDPOINT << "Ignoring packet from unexpected ConnectionId: "
<< header.connection_id << " instead of " << connection_id_;
if (debug_visitor_ != nullptr) {
debug_visitor_->OnIncorrectConnectionId(header.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;
}
bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& 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_EQ(connection_id_, header.public_header.connection_id);
return true;
}
void QuicConnection::OnDecryptedPacket(EncryptionLevel level) {
last_decrypted_packet_level_ = level;
last_packet_decrypted_ = true;
// If this packet was foward-secure encrypted and the forward-secure encrypter
// is not being used, start using it.
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
has_forward_secure_encrypter_ && level == ENCRYPTION_FORWARD_SECURE) {
SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
}
}
bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketHeader(header);
}
if (!ProcessValidatedPacket()) {
return false;
}
// Will be decremented below if we fall through to return true.
++stats_.packets_dropped;
if (!Near(header.packet_sequence_number,
last_header_.packet_sequence_number)) {
DVLOG(1) << ENDPOINT << "Packet " << header.packet_sequence_number
<< " out of bounds. Discarding";
SendConnectionCloseWithDetails(QUIC_INVALID_PACKET_HEADER,
"Packet sequence number out of bounds");
return false;
}
// 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 (!received_packet_manager_.IsAwaitingPacket(
header.packet_sequence_number)) {
DVLOG(1) << ENDPOINT << "Packet " << header.packet_sequence_number
<< " no longer being waited for. Discarding.";
if (debug_visitor_ != nullptr) {
debug_visitor_->OnDuplicatePacket(header.packet_sequence_number);
}
return false;
}
if (version_negotiation_state_ != NEGOTIATED_VERSION) {
if (perspective_ == Perspective::IS_SERVER) {
if (!header.public_header.version_flag) {
DLOG(WARNING) << ENDPOINT << "Packet " << header.packet_sequence_number
<< " without version flag before version negotiated.";
// Packets should have the version flag till version negotiation is
// done.
CloseConnection(QUIC_INVALID_VERSION, false);
return false;
} else {
DCHECK_EQ(1u, header.public_header.versions.size());
DCHECK_EQ(header.public_header.versions[0], version());
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(version());
}
}
} else {
DCHECK(!header.public_header.version_flag);
// If the client gets a packet without the version flag from the server
// it should stop sending version since the version negotiation is done.
packet_generator_.StopSendingVersion();
version_negotiation_state_ = NEGOTIATED_VERSION;
visitor_->OnSuccessfulVersionNegotiation(version());
if (debug_visitor_ != nullptr) {
debug_visitor_->OnSuccessfulVersionNegotiation(version());
}
}
}
DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
--stats_.packets_dropped;
DVLOG(1) << ENDPOINT << "Received packet header: " << header;
last_header_ = header;
DCHECK(connected_);
return true;
}
void QuicConnection::OnFecProtectedPayload(StringPiece payload) {
DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
DCHECK_NE(0u, last_header_.fec_group);
QuicFecGroup* group = GetFecGroup();
if (group != nullptr) {
group->Update(last_decrypted_packet_level_, last_header_, payload);
}
}
bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStreamFrame(frame);
}
if (frame.stream_id != kCryptoStreamId &&
last_decrypted_packet_level_ == ENCRYPTION_NONE) {
DLOG(WARNING) << ENDPOINT
<< "Received an unencrypted data frame: closing connection";
SendConnectionClose(QUIC_UNENCRYPTED_STREAM_DATA);
return false;
}
if (FLAGS_quic_process_frames_inline) {
visitor_->OnStreamFrame(frame);
stats_.stream_bytes_received += frame.data.size();
should_last_packet_instigate_acks_ = true;
} else {
last_stream_frames_.push_back(frame);
}
return connected_;
}
bool QuicConnection::OnAckFrame(const QuicAckFrame& incoming_ack) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnAckFrame(incoming_ack);
}
DVLOG(1) << ENDPOINT << "OnAckFrame: " << incoming_ack;
if (last_header_.packet_sequence_number <= largest_seen_packet_with_ack_) {
DVLOG(1) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
if (!ValidateAckFrame(incoming_ack)) {
SendConnectionClose(QUIC_INVALID_ACK_DATA);
return false;
}
if (FLAGS_quic_process_frames_inline) {
ProcessAckFrame(incoming_ack);
if (incoming_ack.is_truncated) {
should_last_packet_instigate_acks_ = true;
}
if (!incoming_ack.missing_packets.empty() &&
GetLeastUnacked() > *incoming_ack.missing_packets.begin()) {
++stop_waiting_count_;
} else {
stop_waiting_count_ = 0;
}
} else {
last_ack_frames_.push_back(incoming_ack);
}
return connected_;
}
void QuicConnection::ProcessAckFrame(const QuicAckFrame& incoming_ack) {
largest_seen_packet_with_ack_ = last_header_.packet_sequence_number;
sent_packet_manager_.OnIncomingAck(incoming_ack,
time_of_last_received_packet_);
sent_entropy_manager_.ClearEntropyBefore(
sent_packet_manager_.least_packet_awaited_by_peer() - 1);
// 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();
}
void QuicConnection::ProcessStopWaitingFrame(
const QuicStopWaitingFrame& stop_waiting) {
largest_seen_packet_with_stop_waiting_ = last_header_.packet_sequence_number;
received_packet_manager_.UpdatePacketInformationSentByPeer(stop_waiting);
// Possibly close any FecGroups which are now irrelevant.
CloseFecGroupsBefore(stop_waiting.least_unacked + 1);
}
bool QuicConnection::OnStopWaitingFrame(const QuicStopWaitingFrame& frame) {
DCHECK(connected_);
if (last_header_.packet_sequence_number <=
largest_seen_packet_with_stop_waiting_) {
DVLOG(1) << ENDPOINT << "Received an old stop waiting frame: ignoring";
return true;
}
if (!ValidateStopWaitingFrame(frame)) {
SendConnectionClose(QUIC_INVALID_STOP_WAITING_DATA);
return false;
}
if (debug_visitor_ != nullptr) {
debug_visitor_->OnStopWaitingFrame(frame);
}
last_stop_waiting_frames_.push_back(frame);
return connected_;
}
bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPingFrame(frame);
}
if (FLAGS_quic_process_frames_inline) {
should_last_packet_instigate_acks_ = true;
} else {
last_ping_frames_.push_back(frame);
}
return true;
}
bool QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
if (incoming_ack.largest_observed > packet_generator_.sequence_number()) {
DLOG(ERROR) << ENDPOINT << "Peer's observed unsent packet:"
<< incoming_ack.largest_observed << " vs "
<< packet_generator_.sequence_number();
// We got an error for data we have not sent. Error out.
return false;
}
if (incoming_ack.largest_observed < sent_packet_manager_.largest_observed()) {
DLOG(ERROR) << ENDPOINT << "Peer's largest_observed packet decreased:"
<< incoming_ack.largest_observed << " vs "
<< sent_packet_manager_.largest_observed();
// A new ack has a diminished largest_observed value. Error out.
// If this was an old packet, we wouldn't even have checked.
return false;
}
if (!incoming_ack.missing_packets.empty() &&
*incoming_ack.missing_packets.rbegin() > incoming_ack.largest_observed) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.missing_packets.rbegin()
<< " which is greater than largest observed: "
<< incoming_ack.largest_observed;
return false;
}
if (!incoming_ack.missing_packets.empty() &&
*incoming_ack.missing_packets.begin() <
sent_packet_manager_.least_packet_awaited_by_peer()) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.missing_packets.begin()
<< " which is smaller than least_packet_awaited_by_peer_: "
<< sent_packet_manager_.least_packet_awaited_by_peer();
return false;
}
if (!sent_entropy_manager_.IsValidEntropy(
incoming_ack.largest_observed,
incoming_ack.missing_packets,
incoming_ack.entropy_hash)) {
DLOG(ERROR) << ENDPOINT << "Peer sent invalid entropy.";
return false;
}
for (QuicPacketSequenceNumber revived_packet : incoming_ack.revived_packets) {
if (!ContainsKey(incoming_ack.missing_packets, revived_packet)) {
DLOG(ERROR) << ENDPOINT
<< "Peer specified revived packet which was not missing.";
return false;
}
}
return true;
}
bool QuicConnection::ValidateStopWaitingFrame(
const QuicStopWaitingFrame& stop_waiting) {
if (stop_waiting.least_unacked <
received_packet_manager_.peer_least_packet_awaiting_ack()) {
DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
<< stop_waiting.least_unacked << " vs "
<< received_packet_manager_.peer_least_packet_awaiting_ack();
// We never process old ack frames, so this number should only increase.
return false;
}
if (stop_waiting.least_unacked >
last_header_.packet_sequence_number) {
DLOG(ERROR) << ENDPOINT << "Peer sent least_unacked:"
<< stop_waiting.least_unacked
<< " greater than the enclosing packet sequence number:"
<< last_header_.packet_sequence_number;
return false;
}
return true;
}
void QuicConnection::OnFecData(const QuicFecData& fec) {
DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
DCHECK_NE(0u, last_header_.fec_group);
QuicFecGroup* group = GetFecGroup();
if (group != nullptr) {
group->UpdateFec(last_decrypted_packet_level_,
last_header_.packet_sequence_number, fec);
}
}
bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRstStreamFrame(frame);
}
DVLOG(1) << ENDPOINT << "Stream reset with error "
<< QuicUtils::StreamErrorToString(frame.error_code);
if (FLAGS_quic_process_frames_inline) {
visitor_->OnRstStream(frame);
should_last_packet_instigate_acks_ = true;
} else {
last_rst_frames_.push_back(frame);
}
return connected_;
}
bool QuicConnection::OnConnectionCloseFrame(
const QuicConnectionCloseFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionCloseFrame(frame);
}
DVLOG(1) << ENDPOINT << "Connection " << connection_id()
<< " closed with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " " << frame.error_details;
if (FLAGS_quic_process_frames_inline) {
CloseConnection(frame.error_code, true);
} else {
last_close_frames_.push_back(frame);
}
return connected_;
}
bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnGoAwayFrame(frame);
}
DVLOG(1) << ENDPOINT << "Go away received with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " and reason:" << frame.reason_phrase;
if (FLAGS_quic_process_frames_inline) {
visitor_->OnGoAway(frame);
should_last_packet_instigate_acks_ = true;
} else {
last_goaway_frames_.push_back(frame);
}
return connected_;
}
bool QuicConnection::OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnWindowUpdateFrame(frame);
}
DVLOG(1) << ENDPOINT << "WindowUpdate received for stream: "
<< frame.stream_id << " with byte offset: " << frame.byte_offset;
if (FLAGS_quic_process_frames_inline) {
visitor_->OnWindowUpdateFrame(frame);
should_last_packet_instigate_acks_ = true;
} else {
last_window_update_frames_.push_back(frame);
}
return connected_;
}
bool QuicConnection::OnBlockedFrame(const QuicBlockedFrame& frame) {
DCHECK(connected_);
if (debug_visitor_ != nullptr) {
debug_visitor_->OnBlockedFrame(frame);
}
DVLOG(1) << ENDPOINT << "Blocked frame received for stream: "
<< frame.stream_id;
if (FLAGS_quic_process_frames_inline) {
visitor_->OnBlockedFrame(frame);
should_last_packet_instigate_acks_ = true;
} else {
last_blocked_frames_.push_back(frame);
}
return connected_;
}
void QuicConnection::OnPacketComplete() {
// Don't do anything if this packet closed the connection.
if (!connected_) {
ClearLastFrames();
return;
}
DVLOG(1) << ENDPOINT << (last_packet_revived_ ? "Revived" : "Got")
<< " packet " << last_header_.packet_sequence_number << " with " //
<< last_stream_frames_.size() << " stream frames, " //
<< last_ack_frames_.size() << " acks, " //
<< last_stop_waiting_frames_.size() << " stop_waiting, " //
<< last_rst_frames_.size() << " rsts, " //
<< last_goaway_frames_.size() << " goaways, " //
<< last_window_update_frames_.size() << " window updates, " //
<< last_blocked_frames_.size() << " blocked, " //
<< last_ping_frames_.size() << " pings, " //
<< last_close_frames_.size() << " closes " //
<< "for " << last_header_.public_header.connection_id;
++num_packets_received_since_last_ack_sent_;
// Call MaybeQueueAck() before recording the received packet, since we want
// to trigger an ack if the newly received packet was previously missing.
MaybeQueueAck();
// Record received or revived packet to populate ack info correctly before
// processing stream frames, since the processing may result in a response
// packet with a bundled ack.
if (last_packet_revived_) {
received_packet_manager_.RecordPacketRevived(
last_header_.packet_sequence_number);
} else {
received_packet_manager_.RecordPacketReceived(
last_size_, last_header_, time_of_last_received_packet_);
}
if (!FLAGS_quic_process_frames_inline) {
for (const QuicStreamFrame& frame : last_stream_frames_) {
visitor_->OnStreamFrame(frame);
stats_.stream_bytes_received += frame.data.size();
if (!connected_) {
return;
}
}
// Process window updates, blocked, stream resets, acks, then stop waiting.
for (const QuicWindowUpdateFrame& frame : last_window_update_frames_) {
visitor_->OnWindowUpdateFrame(frame);
if (!connected_) {
return;
}
}
for (const QuicBlockedFrame& frame : last_blocked_frames_) {
visitor_->OnBlockedFrame(frame);
if (!connected_) {
return;
}
}
for (const QuicGoAwayFrame& frame : last_goaway_frames_) {
visitor_->OnGoAway(frame);
if (!connected_) {
return;
}
}
for (const QuicRstStreamFrame& frame : last_rst_frames_) {
visitor_->OnRstStream(frame);
if (!connected_) {
return;
}
}
for (const QuicAckFrame& frame : last_ack_frames_) {
ProcessAckFrame(frame);
if (!connected_) {
return;
}
}
if (!last_close_frames_.empty()) {
CloseConnection(last_close_frames_[0].error_code, true);
DCHECK(!connected_);
return;
}
}
// Continue to process stop waiting frames later, because the packet needs
// to be considered 'received' before the entropy can be updated.
for (const QuicStopWaitingFrame& frame : last_stop_waiting_frames_) {
ProcessStopWaitingFrame(frame);
if (!connected_) {
return;
}
}
// If there are new missing packets to report, send an ack immediately.
if (ShouldLastPacketInstigateAck() &&
received_packet_manager_.HasNewMissingPackets()) {
ack_queued_ = true;
ack_alarm_->Cancel();
}
UpdateStopWaitingCount();
ClearLastFrames();
MaybeCloseIfTooManyOutstandingPackets();
}
void QuicConnection::MaybeQueueAck() {
// If the last packet is an ack, don't ack it.
if (!ShouldLastPacketInstigateAck()) {
return;
}
// If the incoming packet was missing, send an ack immediately.
ack_queued_ = received_packet_manager_.IsMissing(
last_header_.packet_sequence_number);
if (!ack_queued_) {
if (ack_alarm_->IsSet()) {
ack_queued_ = true;
} else {
ack_alarm_->Set(
clock_->ApproximateNow().Add(sent_packet_manager_.DelayedAckTime()));
DVLOG(1) << "Ack timer set; next packet or timer will trigger ACK.";
}
}
if (ack_queued_) {
ack_alarm_->Cancel();
}
}
void QuicConnection::ClearLastFrames() {
if (FLAGS_quic_process_frames_inline) {
should_last_packet_instigate_acks_ = false;
last_stop_waiting_frames_.clear();
return;
}
last_stream_frames_.clear();
last_ack_frames_.clear();
last_stop_waiting_frames_.clear();
last_rst_frames_.clear();
last_goaway_frames_.clear();
last_window_update_frames_.clear();
last_blocked_frames_.clear();
last_ping_frames_.clear();
last_close_frames_.clear();
}
void QuicConnection::MaybeCloseIfTooManyOutstandingPackets() {
// This occurs if we don't discard old packets we've sent fast enough.
// It's possible largest observed is less than least unacked.
if (sent_packet_manager_.largest_observed() >
(sent_packet_manager_.GetLeastUnacked() + kMaxTrackedPackets)) {
SendConnectionCloseWithDetails(
QUIC_TOO_MANY_OUTSTANDING_SENT_PACKETS,
StringPrintf("More than %" PRIu64 " outstanding.", kMaxTrackedPackets));
}
// This occurs if there are received packet gaps and the peer does not raise
// the least unacked fast enough.
if (received_packet_manager_.NumTrackedPackets() > kMaxTrackedPackets) {
SendConnectionCloseWithDetails(
QUIC_TOO_MANY_OUTSTANDING_RECEIVED_PACKETS,
StringPrintf("More than %" PRIu64 " outstanding.", kMaxTrackedPackets));
}
}
void QuicConnection::PopulateAckFrame(QuicAckFrame* ack) {
received_packet_manager_.UpdateReceivedPacketInfo(ack,
clock_->ApproximateNow());
}
void QuicConnection::PopulateStopWaitingFrame(
QuicStopWaitingFrame* stop_waiting) {
stop_waiting->least_unacked = GetLeastUnacked();
stop_waiting->entropy_hash = sent_entropy_manager_.GetCumulativeEntropy(
stop_waiting->least_unacked - 1);
}
bool QuicConnection::ShouldLastPacketInstigateAck() const {
if (FLAGS_quic_process_frames_inline && should_last_packet_instigate_acks_) {
return true;
}
if (!FLAGS_quic_process_frames_inline) {
if (!last_stream_frames_.empty() || !last_goaway_frames_.empty() ||
!last_rst_frames_.empty() || !last_window_update_frames_.empty() ||
!last_blocked_frames_.empty() || !last_ping_frames_.empty()) {
return true;
}
if (!last_ack_frames_.empty() && last_ack_frames_.back().is_truncated) {
return true;
}
}
// Always send an ack every 20 packets in order to allow the peer to discard
// information from the SentPacketManager and provide an RTT measurement.
if (num_packets_received_since_last_ack_sent_ >=
kMaxPacketsReceivedBeforeAckSend) {
return true;
}
return false;
}
void QuicConnection::UpdateStopWaitingCount() {
if (last_ack_frames_.empty()) {
return;
}
// If the peer is still waiting for a packet that we are no longer planning to
// send, send an ack to raise the high water mark.
if (!last_ack_frames_.back().missing_packets.empty() &&
GetLeastUnacked() > *last_ack_frames_.back().missing_packets.begin()) {
++stop_waiting_count_;
} else {
stop_waiting_count_ = 0;
}
}
QuicPacketSequenceNumber QuicConnection::GetLeastUnacked() const {
return sent_packet_manager_.GetLeastUnacked();
}
void QuicConnection::MaybeSendInResponseToPacket() {
if (!connected_) {
return;
}
ScopedPacketBundler bundler(this, ack_queued_ ? SEND_ACK : NO_ACK);
// Now that we have received an ack, we might be able to send packets which
// are queued locally, or drain streams which are blocked.
WriteIfNotBlocked();
}
void QuicConnection::SendVersionNegotiationPacket() {
// TODO(alyssar): implement zero server state negotiation.
pending_version_negotiation_packet_ = true;
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return;
}
DVLOG(1) << ENDPOINT << "Sending version negotiation packet: {"
<< QuicVersionVectorToString(framer_.supported_versions()) << "}";
scoped_ptr<QuicEncryptedPacket> version_packet(
packet_generator_.SerializeVersionNegotiationPacket(
framer_.supported_versions()));
WriteResult result = writer_->WritePacket(
version_packet->data(), version_packet->length(),
self_address().address(), peer_address());
if (result.status == WRITE_STATUS_ERROR) {
// We can't send an error as the socket is presumably borked.
CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
return;
}
if (result.status == WRITE_STATUS_BLOCKED) {
visitor_->OnWriteBlocked();
if (writer_->IsWriteBlockedDataBuffered()) {
pending_version_negotiation_packet_ = false;
}
return;
}
pending_version_negotiation_packet_ = false;
}
QuicConsumedData QuicConnection::SendStreamData(
QuicStreamId id,
const QuicIOVector& iov,
QuicStreamOffset offset,
bool fin,
FecProtection fec_protection,
QuicAckNotifier::DelegateInterface* delegate) {
if (!fin && iov.total_length == 0) {
LOG(DFATAL) << "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.)
//
// TODO(jri): Note that ConsumeData may cause a response packet to be sent.
// We may end up sending stale ack information if there are undecryptable
// packets hanging around and/or there are revivable packets which may get
// handled after this packet is sent. Change ScopedPacketBundler to do the
// right thing: check ack_queued_, and then check undecryptable packets and
// also if there is possibility of revival. Only bundle an ack if there's no
// processing left that may cause received_info_ to change.
ScopedRetransmissionScheduler alarm_delayer(this);
ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
return packet_generator_.ConsumeData(id, iov, offset, fin, fec_protection,
delegate);
}
void QuicConnection::SendRstStream(QuicStreamId id,
QuicRstStreamErrorCode error,
QuicStreamOffset bytes_written) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
packet_generator_.AddControlFrame(QuicFrame(new QuicRstStreamFrame(
id, AdjustErrorForVersion(error, version()), bytes_written)));
sent_packet_manager_.CancelRetransmissionsForStream(id);
// Remove all queued packets which only contain data for the reset stream.
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (packet_iterator != queued_packets_.end()) {
RetransmittableFrames* retransmittable_frames =
packet_iterator->serialized_packet.retransmittable_frames;
if (!retransmittable_frames) {
++packet_iterator;
continue;
}
retransmittable_frames->RemoveFramesForStream(id);
if (!retransmittable_frames->frames().empty()) {
++packet_iterator;
continue;
}
delete packet_iterator->serialized_packet.retransmittable_frames;
delete packet_iterator->serialized_packet.packet;
packet_iterator->serialized_packet.retransmittable_frames = nullptr;
packet_iterator->serialized_packet.packet = nullptr;
packet_iterator = queued_packets_.erase(packet_iterator);
}
}
void QuicConnection::SendWindowUpdate(QuicStreamId id,
QuicStreamOffset byte_offset) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
packet_generator_.AddControlFrame(
QuicFrame(new QuicWindowUpdateFrame(id, byte_offset)));
}
void QuicConnection::SendBlocked(QuicStreamId id) {
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
packet_generator_.AddControlFrame(QuicFrame(new QuicBlockedFrame(id)));
}
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 = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
}
stats_.min_rtt_us = min_rtt.ToMicroseconds();
QuicTime::Delta srtt = rtt_stats->smoothed_rtt();
if (srtt.IsZero()) {
// If SRTT has not been set, use initial RTT instead.
srtt = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
}
stats_.srtt_us = srtt.ToMicroseconds();
stats_.estimated_bandwidth = sent_packet_manager_.BandwidthEstimate();
stats_.max_packet_size = packet_generator_.GetMaxPacketLength();
stats_.max_received_packet_size = largest_received_packet_size_;
return stats_;
}
void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
const IPEndPoint& peer_address,
const QuicEncryptedPacket& packet) {
if (!connected_) {
return;
}
// TODO(rtenneti): Remove ScopedTracker below once crbug.com/462789 is fixed.
tracked_objects::ScopedTracker tracking_profile(
FROM_HERE_WITH_EXPLICIT_FUNCTION(
"462789 QuicConnection::ProcessUdpPacket"));
if (debug_visitor_ != nullptr) {
debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
}
last_size_ = packet.length();
CheckForAddressMigration(self_address, peer_address);
stats_.bytes_received += packet.length();
++stats_.packets_received;
ScopedRetransmissionScheduler alarm_delayer(this);
if (!framer_.ProcessPacket(packet)) {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
if (framer_.error() == QUIC_DECRYPTION_FAILURE) {
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
undecryptable_packets_.size() < max_undecryptable_packets_) {
QueueUndecryptablePacket(packet);
} else if (debug_visitor_ != nullptr) {
debug_visitor_->OnUndecryptablePacket();
}
}
DVLOG(1) << ENDPOINT << "Unable to process packet. Last packet processed: "
<< last_header_.packet_sequence_number;
return;
}
++stats_.packets_processed;
MaybeProcessUndecryptablePackets();
MaybeProcessRevivedPacket();
MaybeSendInResponseToPacket();
SetPingAlarm();
}
void QuicConnection::CheckForAddressMigration(
const IPEndPoint& self_address, const IPEndPoint& peer_address) {
peer_ip_changed_ = false;
peer_port_changed_ = false;
self_ip_changed_ = false;
self_port_changed_ = false;
if (peer_address_.address().empty()) {
peer_address_ = peer_address;
}
if (self_address_.address().empty()) {
self_address_ = self_address;
}
if (!peer_address.address().empty() && !peer_address_.address().empty()) {
peer_ip_changed_ = (peer_address.address() != peer_address_.address());
peer_port_changed_ = (peer_address.port() != peer_address_.port());
// Store in case we want to migrate connection in ProcessValidatedPacket.
migrating_peer_ip_ = peer_address.address();
migrating_peer_port_ = peer_address.port();
}
if (!self_address.address().empty() && !self_address_.address().empty()) {
self_ip_changed_ = (self_address.address() != self_address_.address());
self_port_changed_ = (self_address.port() != self_address_.port());
}
}
void QuicConnection::OnCanWrite() {
DCHECK(!writer_->IsWriteBlocked());
WriteQueuedPackets();
WritePendingRetransmissions();
// 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;
}
{ // Limit the scope of the bundler. ACK inclusion happens elsewhere.
ScopedPacketBundler bundler(this, NO_ACK);
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() &&
!resume_writes_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.
resume_writes_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::WriteIfNotBlocked() {
if (!writer_->IsWriteBlocked()) {
OnCanWrite();
}
}
bool QuicConnection::ProcessValidatedPacket() {
if ((peer_ip_changed_ && !FLAGS_quic_allow_ip_migration) ||
self_ip_changed_ || self_port_changed_) {
SendConnectionCloseWithDetails(
QUIC_ERROR_MIGRATING_ADDRESS,
"Neither IP address migration, nor self port migration are supported.");
return false;
}
// TODO(fayang): Use peer_address_changed_ instead of peer_ip_changed_ and
// peer_port_changed_ once FLAGS_quic_allow_ip_migration is deprecated.
if (peer_ip_changed_ || peer_port_changed_) {
IPEndPoint old_peer_address = peer_address_;
peer_address_ = IPEndPoint(
peer_ip_changed_ ? migrating_peer_ip_ : peer_address_.address(),
peer_port_changed_ ? migrating_peer_port_ : peer_address_.port());
DVLOG(1) << ENDPOINT << "Peer's ip:port changed from "
<< old_peer_address.ToString() << " to "
<< peer_address_.ToString() << ", migrating connection.";
}
time_of_last_received_packet_ = clock_->Now();
DVLOG(1) << ENDPOINT << "time of last received packet: "
<< time_of_last_received_packet_.ToDebuggingValue();
if (last_size_ > largest_received_packet_size_) {
largest_received_packet_size_ = last_size_;
}
if (perspective_ == Perspective::IS_SERVER &&
encryption_level_ == ENCRYPTION_NONE &&
last_size_ > packet_generator_.GetMaxPacketLength()) {
set_max_packet_length(last_size_);
}
return true;
}
void QuicConnection::WriteQueuedPackets() {
DCHECK(!writer_->IsWriteBlocked());
if (pending_version_negotiation_packet_) {
SendVersionNegotiationPacket();
}
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (packet_iterator != queued_packets_.end() &&
WritePacket(&(*packet_iterator))) {
packet_iterator = queued_packets_.erase(packet_iterator);
}
}
void QuicConnection::WritePendingRetransmissions() {
// Keep writing as long as there's a pending retransmission which can be
// written.
while (sent_packet_manager_.HasPendingRetransmissions()) {
const QuicSentPacketManager::PendingRetransmission pending =
sent_packet_manager_.NextPendingRetransmission();
if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
break;
}
// Re-packetize the frames with a new sequence number for retransmission.
// Retransmitted data packets do not use FEC, even when it's enabled.
// Retransmitted packets use the same sequence 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.
packet_generator_.FlushAllQueuedFrames();
char buffer[kMaxPacketSize];
SerializedPacket serialized_packet = packet_generator_.ReserializeAllFrames(
pending.retransmittable_frames, pending.sequence_number_length, buffer,
kMaxPacketSize);
if (serialized_packet.packet == nullptr) {
// We failed to serialize the packet, so close the connection.
// CloseConnection does not send close packet, so no infinite loop here.
CloseConnection(QUIC_ENCRYPTION_FAILURE, false);
return;
}
DVLOG(1) << ENDPOINT << "Retransmitting " << pending.sequence_number
<< " as " << serialized_packet.sequence_number;
SendOrQueuePacket(
QueuedPacket(serialized_packet,
pending.retransmittable_frames.encryption_level(),
pending.transmission_type,
pending.sequence_number));
}
}
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) {
return true;
}
return CanWrite(retransmittable);
}
bool QuicConnection::CanWrite(HasRetransmittableData retransmittable) {
if (!connected_) {
return false;
}
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return false;
}
QuicTime now = clock_->Now();
QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(
now, retransmittable);
if (delay.IsInfinite()) {
send_alarm_->Cancel();
return false;
}
// If the scheduler requires a delay, then we can not send this packet now.
if (!delay.IsZero()) {
send_alarm_->Update(now.Add(delay), QuicTime::Delta::FromMilliseconds(1));
DVLOG(1) << ENDPOINT << "Delaying sending " << delay.ToMilliseconds()
<< "ms";
return false;
}
send_alarm_->Cancel();
return true;
}
bool QuicConnection::WritePacket(QueuedPacket* packet) {
if (!WritePacketInner(packet)) {
return false;
}
delete packet->serialized_packet.retransmittable_frames;
delete packet->serialized_packet.packet;
packet->serialized_packet.retransmittable_frames = nullptr;
packet->serialized_packet.packet = nullptr;
return true;
}
bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
if (ShouldDiscardPacket(*packet)) {
++stats_.packets_discarded;
return true;
}
// Connection close packets are encrypted and saved, so don't exit early.
const bool is_connection_close = IsConnectionClose(*packet);
if (writer_->IsWriteBlocked() && !is_connection_close) {
return false;
}
QuicPacketSequenceNumber sequence_number =
packet->serialized_packet.sequence_number;
DCHECK_LE(sequence_number_of_last_sent_packet_, sequence_number);
sequence_number_of_last_sent_packet_ = sequence_number;
QuicEncryptedPacket* encrypted = packet->serialized_packet.packet;
// Connection close packets are eventually owned by TimeWaitListManager.
// Others are deleted at the end of this call.
if (is_connection_close) {
DCHECK(connection_close_packet_.get() == nullptr);
// Clone the packet so it's owned in the future.
connection_close_packet_.reset(encrypted->Clone());
// This assures we won't try to write *forced* packets when blocked.
// Return true to stop processing.
if (writer_->IsWriteBlocked()) {
visitor_->OnWriteBlocked();
return true;
}
}
if (!FLAGS_quic_allow_oversized_packets_for_test) {
DCHECK_LE(encrypted->length(), kMaxPacketSize);
}
DCHECK_LE(encrypted->length(), packet_generator_.GetMaxPacketLength());
DVLOG(1) << ENDPOINT << "Sending packet " << sequence_number << " : "
<< (packet->serialized_packet.is_fec_packet
? "FEC "
: (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA
? "data bearing "
: " ack only ")) << ", encryption level: "
<< QuicUtils::EncryptionLevelToString(packet->encryption_level)
<< ", encrypted length:" << encrypted->length();
DVLOG(2) << ENDPOINT << "packet(" << sequence_number << "): " << std::endl
<< QuicUtils::StringToHexASCIIDump(encrypted->AsStringPiece());
// 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();
WriteResult result = writer_->WritePacket(encrypted->data(),
encrypted->length(),
self_address().address(),
peer_address());
if (result.error_code == ERR_IO_PENDING) {
DCHECK_EQ(WRITE_STATUS_BLOCKED, result.status);
}
if (result.status == WRITE_STATUS_BLOCKED) {
visitor_->OnWriteBlocked();
// If the socket buffers the 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 (!writer_->IsWriteBlockedDataBuffered()) {
return false;
}
}
if (result.status != WRITE_STATUS_ERROR && debug_visitor_ != nullptr) {
// Pass the write result to the visitor.
debug_visitor_->OnPacketSent(packet->serialized_packet,
packet->original_sequence_number,
packet->encryption_level,
packet->transmission_type,
*encrypted,
packet_send_time);
}
if (packet->transmission_type == NOT_RETRANSMISSION) {
time_of_last_sent_new_packet_ = packet_send_time;
}
SetPingAlarm();
MaybeSetFecAlarm(sequence_number);
MaybeSetMtuAlarm();
DVLOG(1) << ENDPOINT << "time we began writing last sent packet: "
<< packet_send_time.ToDebuggingValue();
// TODO(ianswett): Change the sequence number length and other packet creator
// options by a more explicit API than setting a struct value directly,
// perhaps via the NetworkChangeVisitor.
packet_generator_.UpdateSequenceNumberLength(
sent_packet_manager_.least_packet_awaited_by_peer(),
sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
bool reset_retransmission_alarm = sent_packet_manager_.OnPacketSent(
&packet->serialized_packet,
packet->original_sequence_number,
packet_send_time,
encrypted->length(),
packet->transmission_type,
IsRetransmittable(*packet));
if (reset_retransmission_alarm || !retransmission_alarm_->IsSet()) {
SetRetransmissionAlarm();
}
stats_.bytes_sent += result.bytes_written;
++stats_.packets_sent;
if (packet->transmission_type != NOT_RETRANSMISSION) {
stats_.bytes_retransmitted += result.bytes_written;
++stats_.packets_retransmitted;
}
if (result.status == WRITE_STATUS_ERROR) {
OnWriteError(result.error_code);
DLOG(ERROR) << ENDPOINT << "failed writing " << encrypted->length()
<< "bytes "
<< " from host " << self_address().ToStringWithoutPort()
<< " to address " << peer_address().ToString();
return false;
}
return true;
}
bool QuicConnection::ShouldDiscardPacket(const QueuedPacket& packet) {
if (!connected_) {
DVLOG(1) << ENDPOINT
<< "Not sending packet as connection is disconnected.";
return true;
}
QuicPacketSequenceNumber sequence_number =
packet.serialized_packet.sequence_number;
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE &&
packet.encryption_level == ENCRYPTION_NONE) {
// Drop packets that are NULL encrypted since the peer won't accept them
// anymore.
DVLOG(1) << ENDPOINT << "Dropping NULL encrypted packet: "
<< sequence_number << " since the connection is forward secure.";
return true;
}
// If a retransmission has been acked before sending, don't send it.
// This occurs if a packet gets serialized, queued, then discarded.
if (packet.transmission_type != NOT_RETRANSMISSION &&
(!sent_packet_manager_.IsUnacked(packet.original_sequence_number) ||
!sent_packet_manager_.HasRetransmittableFrames(
packet.original_sequence_number))) {
DVLOG(1) << ENDPOINT << "Dropping unacked packet: " << sequence_number
<< " A previous transmission was acked while write blocked.";
return true;
}
return false;
}
void QuicConnection::OnWriteError(int error_code) {
DVLOG(1) << ENDPOINT << "Write failed with error: " << error_code
<< " (" << ErrorToString(error_code) << ")";
// We can't send an error as the socket is presumably borked.
CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
}
void QuicConnection::OnSerializedPacket(
const SerializedPacket& serialized_packet) {
if (serialized_packet.packet == nullptr) {
// We failed to serialize the packet, so close the connection.
// CloseConnection does not send close packet, so no infinite loop here.
CloseConnection(QUIC_ENCRYPTION_FAILURE, false);
return;
}
sent_packet_manager_.OnSerializedPacket(serialized_packet);
if (serialized_packet.is_fec_packet && fec_alarm_->IsSet()) {
// If an FEC packet is serialized with the FEC alarm set, cancel the alarm.
fec_alarm_->Cancel();
}
SendOrQueuePacket(QueuedPacket(serialized_packet, encryption_level_));
}
void QuicConnection::OnResetFecGroup() {
if (!fec_alarm_->IsSet()) {
return;
}
// If an FEC Group is closed with the FEC alarm set, cancel the alarm.
fec_alarm_->Cancel();
}
void QuicConnection::OnCongestionWindowChange() {
packet_generator_.OnCongestionWindowChange(
sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
}
void QuicConnection::OnRttChange() {
// Uses the connection's smoothed RTT. If zero, uses initial_rtt.
QuicTime::Delta rtt = sent_packet_manager_.GetRttStats()->smoothed_rtt();
if (rtt.IsZero()) {
rtt = QuicTime::Delta::FromMicroseconds(
sent_packet_manager_.GetRttStats()->initial_rtt_us());
}
packet_generator_.OnRttChange(rtt);
}
void QuicConnection::OnHandshakeComplete() {
sent_packet_manager_.SetHandshakeConfirmed();
// The client should immediately ack the SHLO to confirm the handshake is
// complete with the server.
if (perspective_ == Perspective::IS_CLIENT && !ack_queued_) {
ack_alarm_->Cancel();
ack_alarm_->Set(clock_->ApproximateNow());
}
}
void QuicConnection::SendOrQueuePacket(QueuedPacket packet) {
// The caller of this function is responsible for checking CanWrite().
if (packet.serialized_packet.packet == nullptr) {
LOG(DFATAL)
<< "packet.serialized_packet.packet == nullptr in to SendOrQueuePacket";
return;
}
sent_entropy_manager_.RecordPacketEntropyHash(
packet.serialized_packet.sequence_number,
packet.serialized_packet.entropy_hash);
if (!WritePacket(&packet)) {
// Take ownership of the underlying encrypted packet.
if (!packet.serialized_packet.packet->owns_buffer()) {
scoped_ptr<QuicEncryptedPacket> encrypted_deleter(
packet.serialized_packet.packet);
packet.serialized_packet.packet =
packet.serialized_packet.packet->Clone();
}
queued_packets_.push_back(packet);
}
// If a forward-secure encrypter is available but is not being used and the
// next sequence number is the first packet which requires
// forward security, start using the forward-secure encrypter.
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
has_forward_secure_encrypter_ &&
packet.serialized_packet.sequence_number >=
first_required_forward_secure_packet_ - 1) {
SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
}
}
void QuicConnection::SendPing() {
if (retransmission_alarm_->IsSet()) {
return;
}
packet_generator_.AddControlFrame(QuicFrame(new QuicPingFrame));
}
void QuicConnection::SendAck() {
ack_alarm_->Cancel();
ack_queued_ = false;
stop_waiting_count_ = 0;
num_packets_received_since_last_ack_sent_ = 0;
packet_generator_.SetShouldSendAck(true);
}
void QuicConnection::OnRetransmissionTimeout() {
if (!sent_packet_manager_.HasUnackedPackets()) {
return;
}
sent_packet_manager_.OnRetransmissionTimeout();
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 TLP case, the SentPacketManager gives the connection the opportunity
// to send new data before retransmitting.
if (sent_packet_manager_.MaybeRetransmitTailLossProbe()) {
// Send the pending retransmission now that it's been queued.
WriteIfNotBlocked();
}
// 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,
QuicEncrypter* encrypter) {
packet_generator_.SetEncrypter(level, encrypter);
if (level == ENCRYPTION_FORWARD_SECURE) {
has_forward_secure_encrypter_ = true;
first_required_forward_secure_packet_ =
sequence_number_of_last_sent_packet_ +
// 3 times the current congestion window (in slow start) should cover
// about two full round trips worth of packets, which should be
// sufficient.
3 * sent_packet_manager_.EstimateMaxPacketsInFlight(
max_packet_length());
}
}
void QuicConnection::SetDefaultEncryptionLevel(EncryptionLevel level) {
encryption_level_ = level;
packet_generator_.set_encryption_level(level);
}
void QuicConnection::SetDecrypter(EncryptionLevel level,
QuicDecrypter* decrypter) {
framer_.SetDecrypter(level, decrypter);
}
void QuicConnection::SetAlternativeDecrypter(EncryptionLevel level,
QuicDecrypter* decrypter,
bool latch_once_used) {
framer_.SetAlternativeDecrypter(level, decrypter, latch_once_used);
}
const QuicDecrypter* QuicConnection::decrypter() const {
return framer_.decrypter();
}
const QuicDecrypter* QuicConnection::alternative_decrypter() const {
return framer_.alternative_decrypter();
}
void QuicConnection::QueueUndecryptablePacket(
const QuicEncryptedPacket& packet) {
DVLOG(1) << ENDPOINT << "Queueing undecryptable packet.";
undecryptable_packets_.push_back(packet.Clone());
}
void QuicConnection::MaybeProcessUndecryptablePackets() {
if (undecryptable_packets_.empty() || encryption_level_ == ENCRYPTION_NONE) {
return;
}
while (connected_ && !undecryptable_packets_.empty()) {
DVLOG(1) << ENDPOINT << "Attempting to process undecryptable packet";
QuicEncryptedPacket* packet = undecryptable_packets_.front();
if (!framer_.ProcessPacket(*packet) &&
framer_.error() == QUIC_DECRYPTION_FAILURE) {
DVLOG(1) << ENDPOINT << "Unable to process undecryptable packet...";
break;
}
DVLOG(1) << ENDPOINT << "Processed undecryptable packet!";
++stats_.packets_processed;
delete packet;
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();
}
}
STLDeleteElements(&undecryptable_packets_);
}
}
void QuicConnection::MaybeProcessRevivedPacket() {
QuicFecGroup* group = GetFecGroup();
if (!connected_ || group == nullptr || !group->CanRevive()) {
return;
}
QuicPacketHeader revived_header;
char revived_payload[kMaxPacketSize];
size_t len = group->Revive(&revived_header, revived_payload, kMaxPacketSize);
revived_header.public_header.connection_id = connection_id_;
revived_header.public_header.connection_id_length =
last_header_.public_header.connection_id_length;
revived_header.public_header.version_flag = false;
revived_header.public_header.reset_flag = false;
revived_header.public_header.sequence_number_length =
last_header_.public_header.sequence_number_length;
revived_header.fec_flag = false;
revived_header.is_in_fec_group = NOT_IN_FEC_GROUP;
revived_header.fec_group = 0;
group_map_.erase(last_header_.fec_group);
last_decrypted_packet_level_ = group->effective_encryption_level();
DCHECK_LT(last_decrypted_packet_level_, NUM_ENCRYPTION_LEVELS);
delete group;
last_packet_revived_ = true;
if (debug_visitor_ != nullptr) {
debug_visitor_->OnRevivedPacket(revived_header,
StringPiece(revived_payload, len));
}
++stats_.packets_revived;
framer_.ProcessRevivedPacket(&revived_header,
StringPiece(revived_payload, len));
}
QuicFecGroup* QuicConnection::GetFecGroup() {
QuicFecGroupNumber fec_group_num = last_header_.fec_group;
if (fec_group_num == 0) {
return nullptr;
}
if (!ContainsKey(group_map_, fec_group_num)) {
if (group_map_.size() >= kMaxFecGroups) { // Too many groups
if (fec_group_num < group_map_.begin()->first) {
// The group being requested is a group we've seen before and deleted.
// Don't recreate it.
return nullptr;
}
// Clear the lowest group number.
delete group_map_.begin()->second;
group_map_.erase(group_map_.begin());
}
group_map_[fec_group_num] = new QuicFecGroup();
}
return group_map_[fec_group_num];
}
void QuicConnection::SendConnectionClose(QuicErrorCode error) {
SendConnectionCloseWithDetails(error, string());
}
void QuicConnection::SendConnectionCloseWithDetails(QuicErrorCode error,
const string& details) {
// If we're write blocked, WritePacket() will not send, but will capture the
// serialized packet.
SendConnectionClosePacket(error, details);
CloseConnection(error, false);
}
void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
const string& details) {
DVLOG(1) << ENDPOINT << "Force closing " << connection_id()
<< " with error " << QuicUtils::ErrorToString(error)
<< " (" << error << ") " << details;
// Don't send explicit connection close packets for timeouts.
// This is particularly important on mobile, where connections are short.
if (silent_close_enabled_ &&
error == QuicErrorCode::QUIC_CONNECTION_TIMED_OUT) {
return;
}
ScopedPacketBundler ack_bundler(this, SEND_ACK);
QuicConnectionCloseFrame* frame = new QuicConnectionCloseFrame();
frame->error_code = error;
frame->error_details = details;
packet_generator_.AddControlFrame(QuicFrame(frame));
packet_generator_.FlushAllQueuedFrames();
}
void QuicConnection::CloseConnection(QuicErrorCode error, bool from_peer) {
if (!connected_) {
DVLOG(1) << "Connection is already closed.";
return;
}
connected_ = false;
if (debug_visitor_ != nullptr) {
debug_visitor_->OnConnectionClosed(error, from_peer);
}
DCHECK(visitor_ != nullptr);
visitor_->OnConnectionClosed(error, from_peer);
// Cancel the alarms so they don't trigger any action now that the
// connection is closed.
ack_alarm_->Cancel();
ping_alarm_->Cancel();
fec_alarm_->Cancel();
resume_writes_alarm_->Cancel();
retransmission_alarm_->Cancel();
send_alarm_->Cancel();
timeout_alarm_->Cancel();
mtu_discovery_alarm_->Cancel();
}
void QuicConnection::SendGoAway(QuicErrorCode error,
QuicStreamId last_good_stream_id,
const string& reason) {
DVLOG(1) << ENDPOINT << "Going away with error "
<< QuicUtils::ErrorToString(error)
<< " (" << error << ")";
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
packet_generator_.AddControlFrame(
QuicFrame(new QuicGoAwayFrame(error, last_good_stream_id, reason)));
}
void QuicConnection::CloseFecGroupsBefore(
QuicPacketSequenceNumber sequence_number) {
FecGroupMap::iterator it = group_map_.begin();
while (it != group_map_.end()) {
// If this is the current group or the group doesn't protect this packet
// we can ignore it.
if (last_header_.fec_group == it->first ||
!it->second->ProtectsPacketsBefore(sequence_number)) {
++it;
continue;
}
QuicFecGroup* fec_group = it->second;
DCHECK(!fec_group->CanRevive());
FecGroupMap::iterator next = it;
++next;
group_map_.erase(it);
delete fec_group;
it = next;
}
}
QuicByteCount QuicConnection::max_packet_length() const {
return packet_generator_.GetMaxPacketLength();
}
void QuicConnection::set_max_packet_length(QuicByteCount length) {
return packet_generator_.SetMaxPacketLength(length, /*force=*/false);
}
bool QuicConnection::HasQueuedData() const {
return pending_version_negotiation_packet_ ||
!queued_packets_.empty() || packet_generator_.HasQueuedFrames();
}
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()) {
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 overall_timeout,
QuicTime::Delta idle_timeout) {
LOG_IF(DFATAL, idle_timeout > overall_timeout)
<< "idle_timeout:" << idle_timeout.ToMilliseconds()
<< " overall_timeout:" << overall_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.Add(QuicTime::Delta::FromSeconds(3));
} else if (idle_timeout > QuicTime::Delta::FromSeconds(1)) {
idle_timeout = idle_timeout.Subtract(QuicTime::Delta::FromSeconds(1));
}
overall_connection_timeout_ = overall_timeout;
idle_network_timeout_ = idle_timeout;
SetTimeoutAlarm();
}
void QuicConnection::CheckForTimeout() {
QuicTime now = clock_->ApproximateNow();
QuicTime time_of_last_packet = max(time_of_last_received_packet_,
time_of_last_sent_new_packet_);
// |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.Subtract(time_of_last_packet);
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_) {
DVLOG(1) << ENDPOINT << "Connection timedout due to no network activity.";
SendConnectionClose(QUIC_CONNECTION_TIMED_OUT);
return;
}
if (!overall_connection_timeout_.IsInfinite()) {
QuicTime::Delta connected_duration =
now.Subtract(stats_.connection_creation_time);
DVLOG(1) << ENDPOINT << "connection time: "
<< connected_duration.ToMicroseconds() << " overall timeout: "
<< overall_connection_timeout_.ToMicroseconds();
if (connected_duration >= overall_connection_timeout_) {
DVLOG(1) << ENDPOINT <<
"Connection timedout due to overall connection timeout.";
SendConnectionClose(QUIC_CONNECTION_OVERALL_TIMED_OUT);
return;
}
}
SetTimeoutAlarm();
}
void QuicConnection::SetTimeoutAlarm() {
QuicTime time_of_last_packet = max(time_of_last_received_packet_,
time_of_last_sent_new_packet_);
QuicTime deadline = time_of_last_packet.Add(idle_network_timeout_);
if (!overall_connection_timeout_.IsInfinite()) {
deadline = min(deadline,
stats_.connection_creation_time.Add(
overall_connection_timeout_));
}
timeout_alarm_->Cancel();
timeout_alarm_->Set(deadline);
}
void QuicConnection::SetPingAlarm() {
if (perspective_ == Perspective::IS_SERVER) {
// Only clients send pings.
return;
}
if (!visitor_->HasOpenDynamicStreams()) {
ping_alarm_->Cancel();
// Don't send a ping unless there are open streams.
return;
}
QuicTime::Delta ping_timeout = QuicTime::Delta::FromSeconds(kPingTimeoutSecs);
ping_alarm_->Update(clock_->ApproximateNow().Add(ping_timeout),
QuicTime::Delta::FromSeconds(1));
}
void QuicConnection::SetRetransmissionAlarm() {
if (delay_setting_retransmission_alarm_) {
pending_retransmission_alarm_ = true;
return;
}
QuicTime retransmission_time = sent_packet_manager_.GetRetransmissionTime();
retransmission_alarm_->Update(retransmission_time,
QuicTime::Delta::FromMilliseconds(1));
}
void QuicConnection::MaybeSetMtuAlarm() {
if (!FLAGS_quic_do_path_mtu_discovery) {
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 (sequence_number_of_last_sent_packet_ >= next_mtu_probe_at_) {
// Use an alarm to send the MTU probe to ensure that no ScopedPacketBundlers
// are active.
mtu_discovery_alarm_->Set(clock_->ApproximateNow());
}
}
QuicConnection::ScopedPacketBundler::ScopedPacketBundler(
QuicConnection* connection,
AckBundling send_ack)
: connection_(connection),
already_in_batch_mode_(connection != nullptr &&
connection->packet_generator_.InBatchMode()) {
if (connection_ == nullptr) {
return;
}
// Move generator into batch mode. If caller wants us to include an ack,
// check the delayed-ack timer to see if there's ack info to be sent.
if (!already_in_batch_mode_) {
DVLOG(1) << "Entering Batch Mode.";
connection_->packet_generator_.StartBatchOperations();
}
// Bundle an ack if the alarm is set or with every second packet if we need to
// raise the peer's least unacked.
bool ack_pending =
connection_->ack_alarm_->IsSet() || connection_->stop_waiting_count_ > 1;
if (send_ack == SEND_ACK || (send_ack == BUNDLE_PENDING_ACK && ack_pending)) {
DVLOG(1) << "Bundling ack with outgoing packet.";
connection_->SendAck();
}
}
QuicConnection::ScopedPacketBundler::~ScopedPacketBundler() {
if (connection_ == nullptr) {
return;
}
// If we changed the generator's batch state, restore original batch state.
if (!already_in_batch_mode_) {
DVLOG(1) << "Leaving Batch Mode.";
connection_->packet_generator_.FinishBatchOperations();
}
DCHECK_EQ(already_in_batch_mode_,
connection_->packet_generator_.InBatchMode());
}
QuicConnection::ScopedRetransmissionScheduler::ScopedRetransmissionScheduler(
QuicConnection* connection)
: connection_(connection),
already_delayed_(connection_->delay_setting_retransmission_alarm_) {
connection_->delay_setting_retransmission_alarm_ = true;
}
QuicConnection::ScopedRetransmissionScheduler::
~ScopedRetransmissionScheduler() {
if (already_delayed_) {
return;
}
connection_->delay_setting_retransmission_alarm_ = false;
if (connection_->pending_retransmission_alarm_) {
connection_->SetRetransmissionAlarm();
connection_->pending_retransmission_alarm_ = false;
}
}
HasRetransmittableData QuicConnection::IsRetransmittable(
const QueuedPacket& 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.serialized_packet.retransmittable_frames != nullptr) {
return HAS_RETRANSMITTABLE_DATA;
} else {
return NO_RETRANSMITTABLE_DATA;
}
}
bool QuicConnection::IsConnectionClose(const QueuedPacket& packet) {
const RetransmittableFrames* retransmittable_frames =
packet.serialized_packet.retransmittable_frames;
if (retransmittable_frames == nullptr) {
return false;
}
for (const QuicFrame& frame : retransmittable_frames->frames()) {
if (frame.type == CONNECTION_CLOSE_FRAME) {
return true;
}
}
return false;
}
void QuicConnection::SendMtuDiscoveryPacket(QuicByteCount target_mtu) {
// Create a listener for the new probe. The ownership of the listener is
// transferred to the AckNotifierManager. The notifier will get destroyed
// before the connection (because it's stored in one of the connection's
// subfields), hence |this| pointer is guaranteed to stay valid at all times.
scoped_refptr<MtuDiscoveryAckListener> last_mtu_discovery_ack_listener(
new MtuDiscoveryAckListener(this, target_mtu));
// Send the probe.
packet_generator_.GenerateMtuDiscoveryPacket(
target_mtu, last_mtu_discovery_ack_listener.get());
}
void QuicConnection::DiscoverMtu() {
DCHECK(!mtu_discovery_alarm_->IsSet());
// Chcek if the MTU has been already increased.
if (mtu_discovery_target_ <= max_packet_length()) {
return;
}
// Schedule the next probe *before* sending the current one. This is
// important, 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_ =
sequence_number_of_last_sent_packet_ + packets_between_mtu_probes_ + 1;
++mtu_probe_count_;
DVLOG(2) << "Sending a path MTU discovery packet #" << mtu_probe_count_;
SendMtuDiscoveryPacket(mtu_discovery_target_);
DCHECK(!mtu_discovery_alarm_->IsSet());
}
} // namespace net