// 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/logging.h"
#include "base/stl_util.h"
#include "net/base/net_errors.h"
#include "net/quic/crypto/quic_decrypter.h"
#include "net/quic/crypto/quic_encrypter.h"
#include "net/quic/iovector.h"
#include "net/quic/quic_bandwidth.h"
#include "net/quic/quic_config.h"
#include "net/quic/quic_utils.h"
using base::hash_map;
using base::hash_set;
using base::StringPiece;
using std::list;
using std::make_pair;
using std::min;
using std::max;
using std::numeric_limits;
using std::vector;
using std::set;
using std::string;
int FLAGS_fake_packet_loss_percentage = 0;
// If true, then QUIC connections will bundle acks with any outgoing packet when
// an ack is being delayed. This is an optimization to reduce ack latency and
// packet count of pure ack packets.
bool FLAGS_bundle_ack_with_outgoing_packet = false;
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;
// Limit the number of undecryptable packets we buffer in
// expectation of the CHLO/SHLO arriving.
const size_t kMaxUndecryptablePackets = 10;
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) {
}
virtual QuicTime OnAlarm() OVERRIDE {
connection_->SendAck();
return QuicTime::Zero();
}
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 RetransmissionAlarm : public QuicAlarm::Delegate {
public:
explicit RetransmissionAlarm(QuicConnection* connection)
: connection_(connection) {
}
virtual QuicTime OnAlarm() OVERRIDE {
connection_->OnRetransmissionTimeout();
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
};
// An alarm that is scheduled when the sent scheduler requires a
// 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) {
}
virtual QuicTime OnAlarm() OVERRIDE {
connection_->WriteIfNotBlocked();
// Never reschedule the alarm, since OnCanWrite does that.
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
};
class TimeoutAlarm : public QuicAlarm::Delegate {
public:
explicit TimeoutAlarm(QuicConnection* connection)
: connection_(connection) {
}
virtual QuicTime OnAlarm() OVERRIDE {
connection_->CheckForTimeout();
// Never reschedule the alarm, since CheckForTimeout does that.
return QuicTime::Zero();
}
private:
QuicConnection* connection_;
};
// Indicates if any of the frames are intended to be sent with FORCE.
// Returns FORCE when one of the frames is a CONNECTION_CLOSE_FRAME.
net::QuicConnection::Force HasForcedFrames(
const RetransmittableFrames* retransmittable_frames) {
if (!retransmittable_frames) {
return net::QuicConnection::NO_FORCE;
}
for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
if (retransmittable_frames->frames()[i].type == CONNECTION_CLOSE_FRAME) {
return net::QuicConnection::FORCE;
}
}
return net::QuicConnection::NO_FORCE;
}
net::IsHandshake HasCryptoHandshake(
const RetransmittableFrames* retransmittable_frames) {
if (!retransmittable_frames) {
return net::NOT_HANDSHAKE;
}
for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
if (retransmittable_frames->frames()[i].type == STREAM_FRAME &&
retransmittable_frames->frames()[i].stream_frame->stream_id ==
kCryptoStreamId) {
return net::IS_HANDSHAKE;
}
}
return net::NOT_HANDSHAKE;
}
} // namespace
#define ENDPOINT (is_server_ ? "Server: " : " Client: ")
QuicConnection::QuicConnection(QuicGuid guid,
IPEndPoint address,
QuicConnectionHelperInterface* helper,
QuicPacketWriter* writer,
bool is_server,
const QuicVersionVector& supported_versions)
: framer_(supported_versions,
helper->GetClock()->ApproximateNow(),
is_server),
helper_(helper),
writer_(writer),
encryption_level_(ENCRYPTION_NONE),
clock_(helper->GetClock()),
random_generator_(helper->GetRandomGenerator()),
guid_(guid),
peer_address_(address),
largest_seen_packet_with_ack_(0),
pending_version_negotiation_packet_(false),
write_blocked_(false),
received_packet_manager_(kTCP),
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))),
debug_visitor_(NULL),
packet_creator_(guid_, &framer_, random_generator_, is_server),
packet_generator_(this, NULL, &packet_creator_),
idle_network_timeout_(
QuicTime::Delta::FromSeconds(kDefaultInitialTimeoutSecs)),
overall_connection_timeout_(QuicTime::Delta::Infinite()),
creation_time_(clock_->ApproximateNow()),
time_of_last_received_packet_(clock_->ApproximateNow()),
time_of_last_sent_packet_(clock_->ApproximateNow()),
sequence_number_of_last_inorder_packet_(0),
sent_packet_manager_(is_server, this, clock_, kTCP),
version_negotiation_state_(START_NEGOTIATION),
is_server_(is_server),
connected_(true),
address_migrating_(false) {
if (!is_server_) {
// Pacing will be enabled if the client negotiates it.
sent_packet_manager_.MaybeEnablePacing();
}
DVLOG(1) << ENDPOINT << "Created connection with guid: " << guid;
timeout_alarm_->Set(clock_->ApproximateNow().Add(idle_network_timeout_));
framer_.set_visitor(this);
framer_.set_received_entropy_calculator(&received_packet_manager_);
}
QuicConnection::~QuicConnection() {
STLDeleteElements(&undecryptable_packets_);
STLDeleteValues(&group_map_);
for (QueuedPacketList::iterator it = queued_packets_.begin();
it != queued_packets_.end(); ++it) {
delete it->packet;
}
}
void QuicConnection::SetFromConfig(const QuicConfig& config) {
DCHECK_LT(0u, config.server_initial_congestion_window());
SetIdleNetworkTimeout(config.idle_connection_state_lifetime());
sent_packet_manager_.SetFromConfig(config);
// TODO(satyamshekhar): Set congestion control and ICSL also.
}
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 cannot decrypt are dropped.
// TODO(rch): add stats to measure this.
if (!connected_ || framer->error() == QUIC_DECRYPTION_FAILURE) {
return;
}
SendConnectionCloseWithDetails(framer->error(), framer->detailed_error());
}
void QuicConnection::OnPacket() {
DCHECK(last_stream_frames_.empty() &&
last_goaway_frames_.empty() &&
last_rst_frames_.empty() &&
last_ack_frames_.empty() &&
last_congestion_frames_.empty());
}
void QuicConnection::OnPublicResetPacket(
const QuicPublicResetPacket& packet) {
if (debug_visitor_) {
debug_visitor_->OnPublicResetPacket(packet);
}
CloseConnection(QUIC_PUBLIC_RESET, true);
}
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 (!is_server_) {
LOG(DFATAL) << ENDPOINT << "Framer called OnProtocolVersionMismatch. "
<< "Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return false;
}
DCHECK_NE(version(), received_version);
if (debug_visitor_) {
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);
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) {
if (is_server_) {
LOG(DFATAL) << ENDPOINT << "Framer parsed VersionNegotiationPacket."
<< " Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return;
}
if (debug_visitor_) {
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 << "negotiating version " << version();
server_supported_versions_ = packet.versions;
version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
RetransmitUnackedPackets(ALL_PACKETS);
}
void QuicConnection::OnRevivedPacket() {
}
bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
return true;
}
bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
if (debug_visitor_) {
debug_visitor_->OnPacketHeader(header);
}
if (!ProcessValidatedPacket()) {
return false;
}
// Will be decrement below if we fall through to return true;
++stats_.packets_dropped;
if (header.public_header.guid != guid_) {
DVLOG(1) << ENDPOINT << "Ignoring packet from unexpected GUID: "
<< header.public_header.guid << " instead of " << guid_;
return false;
}
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 that the sender
// has told us will not be retransmitted, then stop processing the packet.
if (!received_packet_manager_.IsAwaitingPacket(
header.packet_sequence_number)) {
return false;
}
if (version_negotiation_state_ != NEGOTIATED_VERSION) {
if (is_server_) {
if (!header.public_header.version_flag) {
DLOG(WARNING) << ENDPOINT << "Got packet 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());
}
} 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_creator_.StopSendingVersion();
version_negotiation_state_ = NEGOTIATED_VERSION;
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 != NULL) {
group->Update(last_header_, payload);
}
}
bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnStreamFrame(frame);
}
last_stream_frames_.push_back(frame);
return true;
}
bool QuicConnection::OnAckFrame(const QuicAckFrame& incoming_ack) {
DCHECK(connected_);
if (debug_visitor_) {
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;
}
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;
received_packet_manager_.UpdatePacketInformationReceivedByPeer(incoming_ack);
received_packet_manager_.UpdatePacketInformationSentByPeer(incoming_ack);
// Possibly close any FecGroups which are now irrelevant.
CloseFecGroupsBefore(incoming_ack.sent_info.least_unacked + 1);
sent_entropy_manager_.ClearEntropyBefore(
received_packet_manager_.least_packet_awaited_by_peer() - 1);
bool reset_retransmission_alarm =
sent_packet_manager_.OnIncomingAck(incoming_ack.received_info,
time_of_last_received_packet_);
if (sent_packet_manager_.HasPendingRetransmissions()) {
WriteIfNotBlocked();
}
if (reset_retransmission_alarm) {
retransmission_alarm_->Cancel();
// Reset the RTO and FEC alarms if the are unacked packets.
if (sent_packet_manager_.HasUnackedPackets()) {
QuicTime::Delta retransmission_delay =
sent_packet_manager_.GetRetransmissionDelay();
retransmission_alarm_->Set(
clock_->ApproximateNow().Add(retransmission_delay));
}
}
}
bool QuicConnection::OnCongestionFeedbackFrame(
const QuicCongestionFeedbackFrame& feedback) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnCongestionFeedbackFrame(feedback);
}
last_congestion_frames_.push_back(feedback);
return connected_;
}
bool QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
if (incoming_ack.received_info.largest_observed >
packet_creator_.sequence_number()) {
DLOG(ERROR) << ENDPOINT << "Peer's observed unsent packet:"
<< incoming_ack.received_info.largest_observed << " vs "
<< packet_creator_.sequence_number();
// We got an error for data we have not sent. Error out.
return false;
}
if (incoming_ack.received_info.largest_observed <
received_packet_manager_.peer_largest_observed_packet()) {
DLOG(ERROR) << ENDPOINT << "Peer's largest_observed packet decreased:"
<< incoming_ack.received_info.largest_observed << " vs "
<< received_packet_manager_.peer_largest_observed_packet();
// 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.sent_info.least_unacked <
received_packet_manager_.peer_least_packet_awaiting_ack()) {
DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
<< incoming_ack.sent_info.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 (incoming_ack.sent_info.least_unacked >
last_header_.packet_sequence_number) {
DLOG(ERROR) << ENDPOINT << "Peer sent least_unacked:"
<< incoming_ack.sent_info.least_unacked
<< " greater than the enclosing packet sequence number:"
<< last_header_.packet_sequence_number;
return false;
}
if (!incoming_ack.received_info.missing_packets.empty() &&
*incoming_ack.received_info.missing_packets.rbegin() >
incoming_ack.received_info.largest_observed) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.received_info.missing_packets.rbegin()
<< " which is greater than largest observed: "
<< incoming_ack.received_info.largest_observed;
return false;
}
if (!incoming_ack.received_info.missing_packets.empty() &&
*incoming_ack.received_info.missing_packets.begin() <
received_packet_manager_.least_packet_awaited_by_peer()) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.received_info.missing_packets.begin()
<< " which is smaller than least_packet_awaited_by_peer_: "
<< received_packet_manager_.least_packet_awaited_by_peer();
return false;
}
if (!sent_entropy_manager_.IsValidEntropy(
incoming_ack.received_info.largest_observed,
incoming_ack.received_info.missing_packets,
incoming_ack.received_info.entropy_hash)) {
DLOG(ERROR) << ENDPOINT << "Peer sent invalid entropy.";
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 != NULL) {
group->UpdateFec(last_header_.packet_sequence_number,
last_header_.entropy_flag, fec);
}
}
bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnRstStreamFrame(frame);
}
DVLOG(1) << ENDPOINT << "Stream reset with error "
<< QuicUtils::StreamErrorToString(frame.error_code);
last_rst_frames_.push_back(frame);
return connected_;
}
bool QuicConnection::OnConnectionCloseFrame(
const QuicConnectionCloseFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnConnectionCloseFrame(frame);
}
DVLOG(1) << ENDPOINT << "Connection " << guid() << " closed with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " " << frame.error_details;
last_close_frames_.push_back(frame);
return connected_;
}
bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
DCHECK(connected_);
DVLOG(1) << ENDPOINT << "Go away received with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " and reason:" << frame.reason_phrase;
last_goaway_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_ack_frames_.size() << " acks, "
<< last_congestion_frames_.size() << " congestions, "
<< last_goaway_frames_.size() << " goaways, "
<< last_rst_frames_.size() << " rsts, "
<< last_close_frames_.size() << " closes, "
<< last_stream_frames_.size()
<< " stream frames for " << last_header_.public_header.guid;
// Must called before ack processing, because processing acks removes entries
// from unacket_packets_, increasing the least_unacked.
const bool last_packet_should_instigate_ack = ShouldLastPacketInstigateAck();
// If the incoming packet was missing, send an ack immediately.
bool send_ack_immediately = received_packet_manager_.IsMissing(
last_header_.packet_sequence_number);
// Ensure the visitor can process the stream frames before recording and
// processing the rest of the packet.
if (last_stream_frames_.empty() ||
visitor_->OnStreamFrames(last_stream_frames_)) {
received_packet_manager_.RecordPacketReceived(last_size_,
last_header_,
time_of_last_received_packet_,
last_packet_revived_);
for (size_t i = 0; i < last_stream_frames_.size(); ++i) {
stats_.stream_bytes_received +=
last_stream_frames_[i].data.TotalBufferSize();
}
}
// Process stream resets, then acks, then congestion feedback.
for (size_t i = 0; i < last_goaway_frames_.size(); ++i) {
visitor_->OnGoAway(last_goaway_frames_[i]);
}
for (size_t i = 0; i < last_rst_frames_.size(); ++i) {
visitor_->OnRstStream(last_rst_frames_[i]);
}
for (size_t i = 0; i < last_ack_frames_.size(); ++i) {
ProcessAckFrame(last_ack_frames_[i]);
}
for (size_t i = 0; i < last_congestion_frames_.size(); ++i) {
sent_packet_manager_.OnIncomingQuicCongestionFeedbackFrame(
last_congestion_frames_[i], time_of_last_received_packet_);
}
if (!last_close_frames_.empty()) {
CloseConnection(last_close_frames_[0].error_code, true);
DCHECK(!connected_);
}
// If there are new missing packets to report, send an ack immediately.
if (received_packet_manager_.HasNewMissingPackets()) {
send_ack_immediately = true;
}
MaybeSendInResponseToPacket(send_ack_immediately,
last_packet_should_instigate_ack);
ClearLastFrames();
}
void QuicConnection::ClearLastFrames() {
last_stream_frames_.clear();
last_goaway_frames_.clear();
last_rst_frames_.clear();
last_ack_frames_.clear();
last_congestion_frames_.clear();
}
QuicAckFrame* QuicConnection::CreateAckFrame() {
QuicAckFrame* outgoing_ack = new QuicAckFrame();
received_packet_manager_.UpdateReceivedPacketInfo(
&(outgoing_ack->received_info), clock_->ApproximateNow());
UpdateSentPacketInfo(&(outgoing_ack->sent_info));
DVLOG(1) << ENDPOINT << "Creating ack frame: " << *outgoing_ack;
return outgoing_ack;
}
QuicCongestionFeedbackFrame* QuicConnection::CreateFeedbackFrame() {
return new QuicCongestionFeedbackFrame(outgoing_congestion_feedback_);
}
bool QuicConnection::ShouldLastPacketInstigateAck() {
if (!last_stream_frames_.empty() ||
!last_goaway_frames_.empty() ||
!last_rst_frames_.empty()) {
return true;
}
// If the peer is still waiting for a packet that we are no
// longer planning to send, we should send an ack to raise
// the high water mark.
if (!last_ack_frames_.empty() &&
!last_ack_frames_.back().received_info.missing_packets.empty()) {
return sent_packet_manager_.GetLeastUnackedSentPacket() >
*last_ack_frames_.back().received_info.missing_packets.begin();
}
return false;
}
void QuicConnection::MaybeSendInResponseToPacket(
bool send_ack_immediately,
bool last_packet_should_instigate_ack) {
// |include_ack| is false since we decide about ack bundling below.
ScopedPacketBundler bundler(this, false);
if (last_packet_should_instigate_ack) {
// In general, we ack every second packet. When we don't ack the first
// packet, we set the delayed ack alarm. Thus, if the ack alarm is set
// then we know this is the second packet, and we should send an ack.
if (send_ack_immediately || ack_alarm_->IsSet()) {
SendAck();
DCHECK(!ack_alarm_->IsSet());
} else {
ack_alarm_->Set(clock_->ApproximateNow().Add(
sent_packet_manager_.DelayedAckTime()));
DVLOG(1) << "Ack timer set; next packet or timer will trigger ACK.";
}
}
if (!last_ack_frames_.empty()) {
// Now the we have received an ack, we might be able to send packets which
// are queued locally, or drain streams which are blocked.
QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(
time_of_last_received_packet_, NOT_RETRANSMISSION,
HAS_RETRANSMITTABLE_DATA, NOT_HANDSHAKE);
if (delay.IsZero()) {
send_alarm_->Cancel();
WriteIfNotBlocked();
} else if (!delay.IsInfinite()) {
send_alarm_->Cancel();
send_alarm_->Set(time_of_last_received_packet_.Add(delay));
}
}
}
void QuicConnection::SendVersionNegotiationPacket() {
scoped_ptr<QuicEncryptedPacket> version_packet(
packet_creator_.SerializeVersionNegotiationPacket(
framer_.supported_versions()));
// TODO(satyamshekhar): implement zero server state negotiation.
WriteResult result =
writer_->WritePacket(version_packet->data(), version_packet->length(),
self_address().address(), peer_address(), this);
if (result.status == WRITE_STATUS_BLOCKED) {
write_blocked_ = true;
}
if (result.status == WRITE_STATUS_OK ||
(result.status == WRITE_STATUS_BLOCKED &&
writer_->IsWriteBlockedDataBuffered())) {
pending_version_negotiation_packet_ = false;
return;
}
if (result.status == WRITE_STATUS_ERROR) {
// We can't send an error as the socket is presumably borked.
CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
}
pending_version_negotiation_packet_ = true;
}
QuicConsumedData QuicConnection::SendStreamData(
QuicStreamId id,
const IOVector& data,
QuicStreamOffset offset,
bool fin,
QuicAckNotifier::DelegateInterface* delegate) {
if (!fin && data.Empty()) {
LOG(DFATAL) << "Attempt to send empty stream frame";
}
// This notifier will be owned by the AckNotifierManager (or deleted below if
// no data or FIN was consumed).
QuicAckNotifier* notifier = NULL;
if (delegate) {
notifier = new QuicAckNotifier(delegate);
}
// Opportunistically bundle an ack with this outgoing packet, unless it's the
// crypto stream.
ScopedPacketBundler ack_bundler(this, id != kCryptoStreamId);
QuicConsumedData consumed_data =
packet_generator_.ConsumeData(id, data, offset, fin, notifier);
if (notifier &&
(consumed_data.bytes_consumed == 0 && !consumed_data.fin_consumed)) {
// No data was consumed, nor was a fin consumed, so delete the notifier.
delete notifier;
}
return consumed_data;
}
void QuicConnection::SendRstStream(QuicStreamId id,
QuicRstStreamErrorCode error) {
DVLOG(1) << "Sending RST_STREAM: " << id << " code: " << error;
// Opportunistically bundle an ack with this outgoing packet.
ScopedPacketBundler ack_bundler(this, true);
packet_generator_.AddControlFrame(
QuicFrame(new QuicRstStreamFrame(id, error)));
}
const QuicConnectionStats& QuicConnection::GetStats() {
// Update rtt and estimated bandwidth.
stats_.rtt = sent_packet_manager_.SmoothedRtt().ToMicroseconds();
stats_.estimated_bandwidth =
sent_packet_manager_.BandwidthEstimate().ToBytesPerSecond();
return stats_;
}
void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
const IPEndPoint& peer_address,
const QuicEncryptedPacket& packet) {
if (!connected_) {
return;
}
if (debug_visitor_) {
debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
}
last_packet_revived_ = false;
last_size_ = packet.length();
address_migrating_ = false;
if (peer_address_.address().empty()) {
peer_address_ = peer_address;
}
if (self_address_.address().empty()) {
self_address_ = self_address;
}
if (!(peer_address == peer_address_ && self_address == self_address_)) {
address_migrating_ = true;
}
stats_.bytes_received += packet.length();
++stats_.packets_received;
if (!framer_.ProcessPacket(packet)) {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
framer_.error() == QUIC_DECRYPTION_FAILURE &&
undecryptable_packets_.size() < kMaxUndecryptablePackets) {
QueueUndecryptablePacket(packet);
}
DVLOG(1) << ENDPOINT << "Unable to process packet. Last packet processed: "
<< last_header_.packet_sequence_number;
return;
}
MaybeProcessUndecryptablePackets();
MaybeProcessRevivedPacket();
}
bool QuicConnection::OnCanWrite() {
write_blocked_ = false;
return DoWrite();
}
bool QuicConnection::WriteIfNotBlocked() {
if (write_blocked_) {
return false;
}
return DoWrite();
}
bool QuicConnection::DoWrite() {
DCHECK(!write_blocked_);
WriteQueuedPackets();
WritePendingRetransmissions();
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.
if (CanWrite(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA,
pending_handshake)) {
// Set |include_ack| to false in bundler; ack inclusion happens elsewhere.
scoped_ptr<ScopedPacketBundler> bundler(
new ScopedPacketBundler(this, false));
bool all_bytes_written = visitor_->OnCanWrite();
bundler.reset();
// After the visitor writes, it may have caused the socket to become write
// blocked or the congestion manager to prohibit sending, so check again.
pending_handshake = visitor_->HasPendingHandshake() ? IS_HANDSHAKE
: NOT_HANDSHAKE;
if (!all_bytes_written && !resume_writes_alarm_->IsSet() &&
CanWrite(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA,
pending_handshake)) {
// 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 quic connections have had a chance to use the socket.
resume_writes_alarm_->Set(clock_->ApproximateNow());
}
}
return !write_blocked_;
}
bool QuicConnection::ProcessValidatedPacket() {
if (address_migrating_) {
SendConnectionCloseWithDetails(
QUIC_ERROR_MIGRATING_ADDRESS,
"Address migration is not yet a supported feature");
return false;
}
time_of_last_received_packet_ = clock_->Now();
DVLOG(1) << ENDPOINT << "time of last received packet: "
<< time_of_last_received_packet_.ToDebuggingValue();
if (is_server_ && encryption_level_ == ENCRYPTION_NONE &&
last_size_ > options()->max_packet_length) {
options()->max_packet_length = last_size_;
}
return true;
}
bool QuicConnection::WriteQueuedPackets() {
DCHECK(!write_blocked_);
if (pending_version_negotiation_packet_) {
SendVersionNegotiationPacket();
}
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (!write_blocked_ && packet_iterator != queued_packets_.end()) {
if (WritePacket(packet_iterator->encryption_level,
packet_iterator->sequence_number,
packet_iterator->packet,
packet_iterator->transmission_type,
packet_iterator->retransmittable,
packet_iterator->handshake,
packet_iterator->forced)) {
packet_iterator = queued_packets_.erase(packet_iterator);
} else {
// Continue, because some queued packets may still be writable.
// This can happen if a retransmit send fail.
++packet_iterator;
}
}
return !write_blocked_;
}
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 (HasForcedFrames(&pending.retransmittable_frames) == NO_FORCE &&
!CanWrite(pending.transmission_type, HAS_RETRANSMITTABLE_DATA,
HasCryptoHandshake(&pending.retransmittable_frames))) {
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 creator before making a new packet.
// TODO(ianswett): Implement ReserializeAllFrames as a separate path that
// does not require the creator to be flushed.
Flush();
SerializedPacket serialized_packet = packet_creator_.ReserializeAllFrames(
pending.retransmittable_frames.frames(),
pending.sequence_number_length);
DVLOG(1) << ENDPOINT << "Retransmitting " << pending.sequence_number
<< " as " << serialized_packet.sequence_number;
if (debug_visitor_) {
debug_visitor_->OnPacketRetransmitted(
pending.sequence_number, serialized_packet.sequence_number);
}
sent_packet_manager_.OnRetransmittedPacket(
pending.sequence_number, serialized_packet.sequence_number);
SendOrQueuePacket(pending.retransmittable_frames.encryption_level(),
serialized_packet,
pending.transmission_type);
}
}
void QuicConnection::RetransmitUnackedPackets(
RetransmissionType retransmission_type) {
sent_packet_manager_.RetransmitUnackedPackets(retransmission_type);
WriteIfNotBlocked();
}
bool QuicConnection::ShouldGeneratePacket(
TransmissionType transmission_type,
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(transmission_type, retransmittable, handshake);
}
bool QuicConnection::CanWrite(TransmissionType transmission_type,
HasRetransmittableData retransmittable,
IsHandshake handshake) {
if (write_blocked_) {
return false;
}
// TODO(rch): consider removing this check so that if an ACK comes in
// before the alarm goes it, we might be able send out a packet.
// This check assumes that if the send alarm is set, it applies equally to all
// types of transmissions.
if (send_alarm_->IsSet()) {
DVLOG(1) << "Send alarm set. Not sending.";
return false;
}
QuicTime now = clock_->Now();
QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(
now, transmission_type, retransmittable, handshake);
if (delay.IsInfinite()) {
return false;
}
// If the scheduler requires a delay, then we can not send this packet now.
if (!delay.IsZero()) {
send_alarm_->Cancel();
send_alarm_->Set(now.Add(delay));
DVLOG(1) << "Delaying sending.";
return false;
}
return true;
}
void QuicConnection::SetupRetransmissionAlarm(
QuicPacketSequenceNumber sequence_number) {
if (!sent_packet_manager_.HasRetransmittableFrames(sequence_number)) {
DVLOG(1) << ENDPOINT << "Will not retransmit packet " << sequence_number;
return;
}
// Do not set the retransmission alarm if we're already handling one, since
// it will be reset when OnRetransmissionTimeout completes.
if (retransmission_alarm_->IsSet()) {
return;
}
QuicTime::Delta retransmission_delay =
sent_packet_manager_.GetRetransmissionDelay();
retransmission_alarm_->Set(
clock_->ApproximateNow().Add(retransmission_delay));
}
bool QuicConnection::WritePacket(EncryptionLevel level,
QuicPacketSequenceNumber sequence_number,
QuicPacket* packet,
TransmissionType transmission_type,
HasRetransmittableData retransmittable,
IsHandshake handshake,
Force forced) {
if (ShouldDiscardPacket(level, sequence_number, retransmittable)) {
delete packet;
return true;
}
// If we're write blocked, we know we can't write.
if (write_blocked_) {
return false;
}
// If we are not forced and we can't write, then simply return false;
if (forced == NO_FORCE &&
!CanWrite(transmission_type, retransmittable, handshake)) {
return false;
}
// Some encryption algorithms require the packet sequence numbers not be
// repeated.
DCHECK_LE(sequence_number_of_last_inorder_packet_, sequence_number);
// Only increase this when packets have not been queued. Once they're queued
// due to a write block, there is the chance of sending forced and other
// higher priority packets out of order.
if (queued_packets_.empty()) {
sequence_number_of_last_inorder_packet_ = sequence_number;
}
scoped_ptr<QuicEncryptedPacket> encrypted(
framer_.EncryptPacket(level, sequence_number, *packet));
if (encrypted.get() == NULL) {
LOG(DFATAL) << ENDPOINT << "Failed to encrypt packet number "
<< sequence_number;
CloseConnection(QUIC_ENCRYPTION_FAILURE, false);
return false;
}
// If it's the ConnectionClose packet, the only FORCED frame type,
// clone a copy for resending later by the TimeWaitListManager.
if (forced == FORCE) {
DCHECK(connection_close_packet_.get() == NULL);
connection_close_packet_.reset(encrypted->Clone());
}
if (encrypted->length() > options()->max_packet_length) {
LOG(DFATAL) << "Writing an encrypted packet larger than max_packet_length:"
<< options()->max_packet_length << " encrypted length: "
<< encrypted->length();
}
DVLOG(1) << ENDPOINT << "Sending packet number " << sequence_number
<< " : " << (packet->is_fec_packet() ? "FEC " :
(retransmittable == HAS_RETRANSMITTABLE_DATA
? "data bearing " : " ack only "))
<< ", encryption level: "
<< QuicUtils::EncryptionLevelToString(level)
<< ", length:" << packet->length() << ", encrypted length:"
<< encrypted->length();
DVLOG(2) << ENDPOINT << "packet(" << sequence_number << "): " << std::endl
<< QuicUtils::StringToHexASCIIDump(packet->AsStringPiece());
DCHECK(encrypted->length() <= kMaxPacketSize)
<< "Packet " << sequence_number << " will not be read; too large: "
<< packet->length() << " " << encrypted->length() << " "
<< " forced: " << (forced == FORCE ? "yes" : "no");
DCHECK(pending_write_.get() == NULL);
pending_write_.reset(new PendingWrite(sequence_number, transmission_type,
retransmittable, level,
packet->is_fec_packet(),
packet->length()));
WriteResult result =
writer_->WritePacket(encrypted->data(), encrypted->length(),
self_address().address(), peer_address(), this);
if (result.error_code == ERR_IO_PENDING) {
DCHECK_EQ(WRITE_STATUS_BLOCKED, result.status);
}
if (debug_visitor_) {
// Pass the write result to the visitor.
debug_visitor_->OnPacketSent(sequence_number, level, *encrypted, result);
}
if (result.status == WRITE_STATUS_BLOCKED) {
// TODO(satyashekhar): It might be more efficient (fewer system calls), if
// all connections share this variable i.e this becomes a part of
// PacketWriterInterface.
write_blocked_ = true;
// 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 OnPacketSent
// when the packet is actually sent.
if (writer_->IsWriteBlockedDataBuffered()) {
delete packet;
return true;
}
pending_write_.reset();
return false;
}
if (OnPacketSent(result)) {
delete packet;
return true;
}
return false;
}
bool QuicConnection::ShouldDiscardPacket(
EncryptionLevel level,
QuicPacketSequenceNumber sequence_number,
HasRetransmittableData retransmittable) {
if (!connected_) {
DVLOG(1) << ENDPOINT
<< "Not sending packet as connection is disconnected.";
return true;
}
if (encryption_level_ == ENCRYPTION_FORWARD_SECURE &&
level == ENCRYPTION_NONE) {
// Drop packets that are NULL encrypted since the peer won't accept them
// anymore.
DVLOG(1) << ENDPOINT << "Dropping packet: " << sequence_number
<< " since the packet is NULL encrypted.";
sent_packet_manager_.DiscardUnackedPacket(sequence_number);
return true;
}
if (retransmittable == HAS_RETRANSMITTABLE_DATA) {
if (!sent_packet_manager_.IsUnacked(sequence_number)) {
// This is a crazy edge case, but if we retransmit a packet,
// (but have to queue it for some reason) then receive an ack
// for the previous transmission (but not the retransmission)
// then receive a truncated ACK which causes us to raise the
// high water mark, all before we're able to send the packet
// then we can simply drop it.
DVLOG(1) << ENDPOINT << "Dropping packet: " << sequence_number
<< " since it has already been acked.";
return true;
}
if (sent_packet_manager_.IsPreviousTransmission(sequence_number)) {
// If somehow we have already retransmitted this packet *before*
// we actually send it for the first time (I think this is probably
// impossible in the real world), then don't bother sending it.
// We don't want to call DiscardUnackedPacket because in this case
// the peer has not yet ACK'd the data. We need the subsequent
// retransmission to be sent.
DVLOG(1) << ENDPOINT << "Dropping packet: " << sequence_number
<< " since it has already been retransmitted.";
return true;
}
if (!sent_packet_manager_.HasRetransmittableFrames(sequence_number)) {
DVLOG(1) << ENDPOINT << "Dropping packet: " << sequence_number
<< " since a previous transmission has been acked.";
sent_packet_manager_.DiscardUnackedPacket(sequence_number);
return true;
}
}
return false;
}
bool QuicConnection::OnPacketSent(WriteResult result) {
DCHECK_NE(WRITE_STATUS_BLOCKED, result.status);
if (pending_write_.get() == NULL) {
LOG(DFATAL) << "OnPacketSent called without a pending write.";
return false;
}
QuicPacketSequenceNumber sequence_number = pending_write_->sequence_number;
TransmissionType transmission_type = pending_write_->transmission_type;
HasRetransmittableData retransmittable = pending_write_->retransmittable;
bool is_fec_packet = pending_write_->is_fec_packet;
size_t length = pending_write_->length;
pending_write_.reset();
if (result.status == WRITE_STATUS_ERROR) {
DVLOG(1) << "Write failed with error code: " << result.error_code;
// We can't send an error as the socket is presumably borked.
CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
return false;
}
QuicTime now = clock_->Now();
if (transmission_type == NOT_RETRANSMISSION) {
time_of_last_sent_packet_ = now;
}
DVLOG(1) << ENDPOINT << "time of last sent packet: "
<< now.ToDebuggingValue();
// Set the retransmit alarm only when we have sent the packet to the client
// and not when it goes to the pending queue, otherwise we will end up adding
// an entry to retransmission_timeout_ every time we attempt a write.
if (retransmittable == HAS_RETRANSMITTABLE_DATA || is_fec_packet) {
SetupRetransmissionAlarm(sequence_number);
}
// TODO(ianswett): Change the sequence number length and other packet creator
// options by a more explicit API than setting a struct value directly.
packet_creator_.UpdateSequenceNumberLength(
received_packet_manager_.least_packet_awaited_by_peer(),
sent_packet_manager_.BandwidthEstimate().ToBytesPerPeriod(
sent_packet_manager_.SmoothedRtt()));
sent_packet_manager_.OnPacketSent(sequence_number, now, length,
transmission_type, retransmittable);
stats_.bytes_sent += result.bytes_written;
++stats_.packets_sent;
if (transmission_type == NACK_RETRANSMISSION ||
transmission_type == RTO_RETRANSMISSION) {
stats_.bytes_retransmitted += result.bytes_written;
++stats_.packets_retransmitted;
}
return true;
}
bool QuicConnection::OnSerializedPacket(
const SerializedPacket& serialized_packet) {
if (serialized_packet.retransmittable_frames) {
serialized_packet.retransmittable_frames->
set_encryption_level(encryption_level_);
}
sent_packet_manager_.OnSerializedPacket(serialized_packet);
// The TransmissionType is NOT_RETRANSMISSION because all retransmissions
// serialize packets and invoke SendOrQueuePacket directly.
return SendOrQueuePacket(encryption_level_,
serialized_packet,
NOT_RETRANSMISSION);
}
QuicPacketSequenceNumber QuicConnection::GetNextPacketSequenceNumber() {
return packet_creator_.sequence_number() + 1;
}
bool QuicConnection::SendOrQueuePacket(EncryptionLevel level,
const SerializedPacket& packet,
TransmissionType transmission_type) {
IsHandshake handshake = HasCryptoHandshake(packet.retransmittable_frames);
Force forced = HasForcedFrames(packet.retransmittable_frames);
HasRetransmittableData retransmittable =
(transmission_type != NOT_RETRANSMISSION ||
packet.retransmittable_frames != NULL) ?
HAS_RETRANSMITTABLE_DATA : NO_RETRANSMITTABLE_DATA;
sent_entropy_manager_.RecordPacketEntropyHash(packet.sequence_number,
packet.entropy_hash);
if (WritePacket(level, packet.sequence_number, packet.packet,
transmission_type, retransmittable, handshake, forced)) {
return true;
}
queued_packets_.push_back(QueuedPacket(packet.sequence_number, packet.packet,
level, transmission_type,
retransmittable, handshake, forced));
return false;
}
void QuicConnection::UpdateSentPacketInfo(SentPacketInfo* sent_info) {
sent_info->least_unacked = sent_packet_manager_.GetLeastUnackedSentPacket();
sent_info->entropy_hash = sent_entropy_manager_.EntropyHash(
sent_info->least_unacked - 1);
}
void QuicConnection::SendAck() {
ack_alarm_->Cancel();
// TODO(rch): delay this until the CreateFeedbackFrame
// method is invoked. This requires changes SetShouldSendAck
// to be a no-arg method, and re-jiggering its implementation.
bool send_feedback = false;
if (received_packet_manager_.GenerateCongestionFeedback(
&outgoing_congestion_feedback_)) {
DVLOG(1) << ENDPOINT << "Sending feedback: "
<< outgoing_congestion_feedback_;
send_feedback = true;
}
packet_generator_.SetShouldSendAck(send_feedback);
}
void QuicConnection::OnRetransmissionTimeout() {
if (!sent_packet_manager_.HasUnackedPackets()) {
return;
}
++stats_.rto_count;
sent_packet_manager_.OnRetransmissionTimeout();
WriteIfNotBlocked();
// Ensure the retransmission alarm is always set if there are unacked packets.
if (sent_packet_manager_.HasUnackedPackets() && !HasQueuedData() &&
!retransmission_alarm_->IsSet()) {
QuicTime rto_timeout = clock_->ApproximateNow().Add(
sent_packet_manager_.GetRetransmissionDelay());
retransmission_alarm_->Set(rto_timeout);
}
}
void QuicConnection::SetEncrypter(EncryptionLevel level,
QuicEncrypter* encrypter) {
framer_.SetEncrypter(level, encrypter);
}
const QuicEncrypter* QuicConnection::encrypter(EncryptionLevel level) const {
return framer_.encrypter(level);
}
void QuicConnection::SetDefaultEncryptionLevel(
EncryptionLevel level) {
encryption_level_ = level;
}
void QuicConnection::SetDecrypter(QuicDecrypter* decrypter) {
framer_.SetDecrypter(decrypter);
}
void QuicConnection::SetAlternativeDecrypter(QuicDecrypter* decrypter,
bool latch_once_used) {
framer_.SetAlternativeDecrypter(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!";
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) {
STLDeleteElements(&undecryptable_packets_);
}
}
void QuicConnection::MaybeProcessRevivedPacket() {
QuicFecGroup* group = GetFecGroup();
if (!connected_ || group == NULL || !group->CanRevive()) {
return;
}
QuicPacketHeader revived_header;
char revived_payload[kMaxPacketSize];
size_t len = group->Revive(&revived_header, revived_payload, kMaxPacketSize);
revived_header.public_header.guid = guid_;
revived_header.public_header.version_flag = false;
revived_header.public_header.reset_flag = false;
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);
delete group;
last_packet_revived_ = true;
if (debug_visitor_) {
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 NULL;
}
if (group_map_.count(fec_group_num) == 0) {
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 NULL;
}
// 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 (!write_blocked_) {
SendConnectionClosePacket(error, details);
}
CloseConnection(error, false);
}
void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
const string& details) {
DVLOG(1) << ENDPOINT << "Force closing " << guid() << " with error "
<< QuicUtils::ErrorToString(error) << " (" << error << ") "
<< details;
ScopedPacketBundler ack_bundler(this, true);
QuicConnectionCloseFrame* frame = new QuicConnectionCloseFrame();
frame->error_code = error;
frame->error_details = details;
packet_generator_.AddControlFrame(QuicFrame(frame));
Flush();
}
void QuicConnection::CloseConnection(QuicErrorCode error, bool from_peer) {
DCHECK(connected_);
connected_ = false;
visitor_->OnConnectionClosed(error, from_peer);
// Cancel the alarms so they don't trigger any action now that the
// connection is closed.
ack_alarm_->Cancel();
resume_writes_alarm_->Cancel();
retransmission_alarm_->Cancel();
send_alarm_->Cancel();
timeout_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, true);
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;
}
}
void QuicConnection::Flush() {
packet_generator_.FlushAllQueuedFrames();
}
bool QuicConnection::HasQueuedData() const {
return pending_version_negotiation_packet_ ||
!queued_packets_.empty() || packet_generator_.HasQueuedFrames();
}
void QuicConnection::SetIdleNetworkTimeout(QuicTime::Delta timeout) {
if (timeout < idle_network_timeout_) {
idle_network_timeout_ = timeout;
CheckForTimeout();
} else {
idle_network_timeout_ = timeout;
}
}
void QuicConnection::SetOverallConnectionTimeout(QuicTime::Delta timeout) {
if (timeout < overall_connection_timeout_) {
overall_connection_timeout_ = timeout;
CheckForTimeout();
} else {
overall_connection_timeout_ = timeout;
}
}
bool QuicConnection::CheckForTimeout() {
QuicTime now = clock_->ApproximateNow();
QuicTime time_of_last_packet = std::max(time_of_last_received_packet_,
time_of_last_sent_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 delta = now.Subtract(time_of_last_packet);
DVLOG(1) << ENDPOINT << "last packet "
<< time_of_last_packet.ToDebuggingValue()
<< " now:" << now.ToDebuggingValue()
<< " delta:" << delta.ToMicroseconds()
<< " network_timeout: " << idle_network_timeout_.ToMicroseconds();
if (delta >= idle_network_timeout_) {
DVLOG(1) << ENDPOINT << "Connection timedout due to no network activity.";
SendConnectionClose(QUIC_CONNECTION_TIMED_OUT);
return true;
}
// Next timeout delta.
QuicTime::Delta timeout = idle_network_timeout_.Subtract(delta);
if (!overall_connection_timeout_.IsInfinite()) {
QuicTime::Delta connected_time = now.Subtract(creation_time_);
DVLOG(1) << ENDPOINT << "connection time: "
<< connected_time.ToMilliseconds() << " overall timeout: "
<< overall_connection_timeout_.ToMilliseconds();
if (connected_time >= overall_connection_timeout_) {
DVLOG(1) << ENDPOINT <<
"Connection timedout due to overall connection timeout.";
SendConnectionClose(QUIC_CONNECTION_TIMED_OUT);
return true;
}
// Take the min timeout.
QuicTime::Delta connection_timeout =
overall_connection_timeout_.Subtract(connected_time);
if (connection_timeout < timeout) {
timeout = connection_timeout;
}
}
timeout_alarm_->Cancel();
timeout_alarm_->Set(clock_->ApproximateNow().Add(timeout));
return false;
}
QuicConnection::ScopedPacketBundler::ScopedPacketBundler(
QuicConnection* connection,
bool include_ack)
: connection_(connection),
already_in_batch_mode_(connection->packet_generator_.InBatchMode()) {
// 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();
}
if (include_ack && connection_->ack_alarm_->IsSet()) {
DVLOG(1) << "Bundling ack with outgoing packet.";
connection_->SendAck();
}
}
QuicConnection::ScopedPacketBundler::~ScopedPacketBundler() {
// 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());
}
} // namespace net