blob: 14d549a38880ddb78ab76304a6c8f46b992debcf [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 "quic/core/quic_session.h"
#include <cstdint>
#include <string>
#include <utility>
#include "absl/memory/memory.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "quic/core/frames/quic_ack_frequency_frame.h"
#include "quic/core/frames/quic_window_update_frame.h"
#include "quic/core/quic_connection.h"
#include "quic/core/quic_connection_context.h"
#include "quic/core/quic_error_codes.h"
#include "quic/core/quic_flow_controller.h"
#include "quic/core/quic_types.h"
#include "quic/core/quic_utils.h"
#include "quic/core/quic_versions.h"
#include "quic/platform/api/quic_bug_tracker.h"
#include "quic/platform/api/quic_flag_utils.h"
#include "quic/platform/api/quic_flags.h"
#include "quic/platform/api/quic_logging.h"
#include "quic/platform/api/quic_server_stats.h"
#include "quic/platform/api/quic_stack_trace.h"
#include "common/quiche_text_utils.h"
using spdy::SpdyPriority;
namespace quic {
namespace {
class ClosedStreamsCleanUpDelegate : public QuicAlarm::Delegate {
public:
explicit ClosedStreamsCleanUpDelegate(QuicSession* session)
: session_(session) {}
ClosedStreamsCleanUpDelegate(const ClosedStreamsCleanUpDelegate&) = delete;
ClosedStreamsCleanUpDelegate& operator=(const ClosedStreamsCleanUpDelegate&) =
delete;
QuicConnectionContext* GetConnectionContext() override {
return (session_->connection() == nullptr)
? nullptr
: session_->connection()->context();
}
void OnAlarm() override { session_->CleanUpClosedStreams(); }
private:
QuicSession* session_;
};
} // namespace
#define ENDPOINT \
(perspective() == Perspective::IS_SERVER ? "Server: " : "Client: ")
QuicSession::QuicSession(
QuicConnection* connection, Visitor* owner, const QuicConfig& config,
const ParsedQuicVersionVector& supported_versions,
QuicStreamCount num_expected_unidirectional_static_streams)
: QuicSession(connection, owner, config, supported_versions,
num_expected_unidirectional_static_streams, nullptr) {}
QuicSession::QuicSession(
QuicConnection* connection, Visitor* owner, const QuicConfig& config,
const ParsedQuicVersionVector& supported_versions,
QuicStreamCount num_expected_unidirectional_static_streams,
std::unique_ptr<QuicDatagramQueue::Observer> datagram_observer)
: connection_(connection),
perspective_(connection->perspective()),
visitor_(owner),
write_blocked_streams_(connection->transport_version()),
config_(config),
stream_id_manager_(perspective(), connection->transport_version(),
kDefaultMaxStreamsPerConnection,
config_.GetMaxBidirectionalStreamsToSend()),
ietf_streamid_manager_(perspective(), connection->version(), this, 0,
num_expected_unidirectional_static_streams,
config_.GetMaxBidirectionalStreamsToSend(),
config_.GetMaxUnidirectionalStreamsToSend() +
num_expected_unidirectional_static_streams),
num_draining_streams_(0),
num_outgoing_draining_streams_(0),
num_static_streams_(0),
num_zombie_streams_(0),
flow_controller_(
this, QuicUtils::GetInvalidStreamId(connection->transport_version()),
/*is_connection_flow_controller*/ true,
connection->version().AllowsLowFlowControlLimits()
? 0
: kMinimumFlowControlSendWindow,
config_.GetInitialSessionFlowControlWindowToSend(),
kSessionReceiveWindowLimit, perspective() == Perspective::IS_SERVER,
nullptr),
currently_writing_stream_id_(0),
transport_goaway_sent_(false),
transport_goaway_received_(false),
control_frame_manager_(this),
last_message_id_(0),
datagram_queue_(this, std::move(datagram_observer)),
closed_streams_clean_up_alarm_(nullptr),
supported_versions_(supported_versions),
is_configured_(false),
was_zero_rtt_rejected_(false),
liveness_testing_in_progress_(false) {
closed_streams_clean_up_alarm_ =
absl::WrapUnique<QuicAlarm>(connection_->alarm_factory()->CreateAlarm(
new ClosedStreamsCleanUpDelegate(this)));
if (perspective() == Perspective::IS_SERVER &&
connection_->version().handshake_protocol == PROTOCOL_TLS1_3) {
config_.SetStatelessResetTokenToSend(GetStatelessResetToken());
}
if (VersionHasIetfQuicFrames(transport_version())) {
config_.SetMaxUnidirectionalStreamsToSend(
config_.GetMaxUnidirectionalStreamsToSend() +
num_expected_unidirectional_static_streams);
}
}
void QuicSession::Initialize() {
connection_->set_visitor(this);
connection_->SetSessionNotifier(this);
connection_->SetDataProducer(this);
connection_->SetUnackedMapInitialCapacity();
connection_->SetFromConfig(config_);
if (perspective_ == Perspective::IS_CLIENT) {
if (config_.HasClientRequestedIndependentOption(kAFFE, perspective_) &&
version().HasIetfQuicFrames()) {
connection_->set_can_receive_ack_frequency_frame();
config_.SetMinAckDelayMs(kDefaultMinAckDelayTimeMs);
}
if (config_.HasClientRequestedIndependentOption(kNBPE, perspective_)) {
permutes_tls_extensions_ = false;
}
}
connection_->CreateConnectionIdManager();
// On the server side, version negotiation has been done by the dispatcher,
// and the server session is created with the right version.
if (perspective() == Perspective::IS_SERVER) {
connection_->OnSuccessfulVersionNegotiation();
}
if (GetMutableCryptoStream()->KeyUpdateSupportedLocally()) {
config_.SetKeyUpdateSupportedLocally();
}
if (QuicVersionUsesCryptoFrames(transport_version())) {
return;
}
QUICHE_DCHECK_EQ(QuicUtils::GetCryptoStreamId(transport_version()),
GetMutableCryptoStream()->id());
}
QuicSession::~QuicSession() {
if (closed_streams_clean_up_alarm_ != nullptr) {
closed_streams_clean_up_alarm_->PermanentCancel();
}
}
PendingStream* QuicSession::PendingStreamOnStreamFrame(
const QuicStreamFrame& frame) {
QUICHE_DCHECK(VersionUsesHttp3(transport_version()));
QuicStreamId stream_id = frame.stream_id;
PendingStream* pending = GetOrCreatePendingStream(stream_id);
if (!pending) {
if (frame.fin) {
QuicStreamOffset final_byte_offset = frame.offset + frame.data_length;
OnFinalByteOffsetReceived(stream_id, final_byte_offset);
}
return nullptr;
}
pending->OnStreamFrame(frame);
if (!connection()->connected()) {
return nullptr;
}
return pending;
}
void QuicSession::MaybeProcessPendingStream(PendingStream* pending) {
QUICHE_DCHECK(pending != nullptr);
QuicStreamId stream_id = pending->id();
absl::optional<QuicResetStreamError> stop_sending_error_code =
pending->GetStopSendingErrorCode();
QuicStream* stream = ProcessPendingStream(pending);
if (stream != nullptr) {
// The pending stream should now be in the scope of normal streams.
QUICHE_DCHECK(IsClosedStream(stream_id) || IsOpenStream(stream_id))
<< "Stream " << stream_id << " not created";
pending_stream_map_.erase(stream_id);
if (stop_sending_error_code) {
stream->OnStopSending(*stop_sending_error_code);
if (!connection()->connected()) {
return;
}
}
stream->OnStreamCreatedFromPendingStream();
return;
}
// At this point, none of the bytes has been successfully consumed by the
// application layer. We should close the pending stream even if it is
// bidirectionl as no application will be able to write in a bidirectional
// stream with zero byte as input.
if (pending->sequencer()->IsClosed()) {
ClosePendingStream(stream_id);
}
}
void QuicSession::PendingStreamOnWindowUpdateFrame(
const QuicWindowUpdateFrame& frame) {
QUICHE_DCHECK(VersionUsesHttp3(transport_version()));
PendingStream* pending = GetOrCreatePendingStream(frame.stream_id);
if (pending) {
pending->OnWindowUpdateFrame(frame);
}
}
void QuicSession::PendingStreamOnStopSendingFrame(
const QuicStopSendingFrame& frame) {
QUICHE_DCHECK(VersionUsesHttp3(transport_version()));
PendingStream* pending = GetOrCreatePendingStream(frame.stream_id);
if (pending) {
pending->OnStopSending(frame.error());
}
}
void QuicSession::OnStreamFrame(const QuicStreamFrame& frame) {
QuicStreamId stream_id = frame.stream_id;
if (stream_id == QuicUtils::GetInvalidStreamId(transport_version())) {
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Received data for an invalid stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (ShouldProcessFrameByPendingStream(STREAM_FRAME, stream_id)) {
PendingStream* pending = PendingStreamOnStreamFrame(frame);
if (pending != nullptr && ShouldProcessPendingStreamImmediately()) {
MaybeProcessPendingStream(pending);
}
return;
}
QuicStream* stream = GetOrCreateStream(stream_id);
if (!stream) {
// The stream no longer exists, but we may still be interested in the
// final stream byte offset sent by the peer. A frame with a FIN can give
// us this offset.
if (frame.fin) {
QuicStreamOffset final_byte_offset = frame.offset + frame.data_length;
OnFinalByteOffsetReceived(stream_id, final_byte_offset);
}
return;
}
stream->OnStreamFrame(frame);
}
void QuicSession::OnCryptoFrame(const QuicCryptoFrame& frame) {
GetMutableCryptoStream()->OnCryptoFrame(frame);
}
void QuicSession::OnStopSendingFrame(const QuicStopSendingFrame& frame) {
// STOP_SENDING is in IETF QUIC only.
QUICHE_DCHECK(VersionHasIetfQuicFrames(transport_version()));
QUICHE_DCHECK(QuicVersionUsesCryptoFrames(transport_version()));
QuicStreamId stream_id = frame.stream_id;
// If Stream ID is invalid then close the connection.
// TODO(ianswett): This check is redundant to checks for IsClosedStream,
// but removing it requires removing multiple QUICHE_DCHECKs.
// TODO(ianswett): Multiple QUIC_DVLOGs could be QUIC_PEER_BUGs.
if (stream_id == QuicUtils::GetInvalidStreamId(transport_version())) {
QUIC_DVLOG(1) << ENDPOINT
<< "Received STOP_SENDING with invalid stream_id: "
<< stream_id << " Closing connection";
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Received STOP_SENDING for an invalid stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
// If stream_id is READ_UNIDIRECTIONAL, close the connection.
if (QuicUtils::GetStreamType(stream_id, perspective(),
IsIncomingStream(stream_id),
version()) == READ_UNIDIRECTIONAL) {
QUIC_DVLOG(1) << ENDPOINT
<< "Received STOP_SENDING for a read-only stream_id: "
<< stream_id << ".";
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Received STOP_SENDING for a read-only stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (visitor_) {
visitor_->OnStopSendingReceived(frame);
}
if (ShouldProcessFrameByPendingStream(STOP_SENDING_FRAME, stream_id)) {
PendingStreamOnStopSendingFrame(frame);
return;
}
QuicStream* stream = GetOrCreateStream(stream_id);
if (!stream) {
// Errors are handled by GetOrCreateStream.
return;
}
stream->OnStopSending(frame.error());
}
void QuicSession::OnPacketDecrypted(EncryptionLevel level) {
GetMutableCryptoStream()->OnPacketDecrypted(level);
if (liveness_testing_in_progress_) {
liveness_testing_in_progress_ = false;
OnCanCreateNewOutgoingStream(/*unidirectional=*/false);
}
}
void QuicSession::OnOneRttPacketAcknowledged() {
GetMutableCryptoStream()->OnOneRttPacketAcknowledged();
}
void QuicSession::OnHandshakePacketSent() {
GetMutableCryptoStream()->OnHandshakePacketSent();
}
std::unique_ptr<QuicDecrypter>
QuicSession::AdvanceKeysAndCreateCurrentOneRttDecrypter() {
return GetMutableCryptoStream()->AdvanceKeysAndCreateCurrentOneRttDecrypter();
}
std::unique_ptr<QuicEncrypter> QuicSession::CreateCurrentOneRttEncrypter() {
return GetMutableCryptoStream()->CreateCurrentOneRttEncrypter();
}
void QuicSession::PendingStreamOnRstStream(const QuicRstStreamFrame& frame) {
QUICHE_DCHECK(VersionUsesHttp3(transport_version()));
QuicStreamId stream_id = frame.stream_id;
PendingStream* pending = GetOrCreatePendingStream(stream_id);
if (!pending) {
HandleRstOnValidNonexistentStream(frame);
return;
}
pending->OnRstStreamFrame(frame);
// At this point, none of the bytes has been consumed by the application
// layer. It is safe to close the pending stream even if it is bidirectionl as
// no application will be able to write in a bidirectional stream with zero
// byte as input.
ClosePendingStream(stream_id);
}
void QuicSession::OnRstStream(const QuicRstStreamFrame& frame) {
QuicStreamId stream_id = frame.stream_id;
if (stream_id == QuicUtils::GetInvalidStreamId(transport_version())) {
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Received data for an invalid stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (VersionHasIetfQuicFrames(transport_version()) &&
QuicUtils::GetStreamType(stream_id, perspective(),
IsIncomingStream(stream_id),
version()) == WRITE_UNIDIRECTIONAL) {
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Received RESET_STREAM for a write-only stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (visitor_) {
visitor_->OnRstStreamReceived(frame);
}
if (ShouldProcessFrameByPendingStream(RST_STREAM_FRAME, stream_id)) {
PendingStreamOnRstStream(frame);
return;
}
QuicStream* stream = GetOrCreateStream(stream_id);
if (!stream) {
HandleRstOnValidNonexistentStream(frame);
return; // Errors are handled by GetOrCreateStream.
}
stream->OnStreamReset(frame);
}
void QuicSession::OnGoAway(const QuicGoAwayFrame& /*frame*/) {
QUIC_BUG_IF(quic_bug_12435_1, version().UsesHttp3())
<< "gQUIC GOAWAY received on version " << version();
transport_goaway_received_ = true;
}
void QuicSession::OnMessageReceived(absl::string_view message) {
QUIC_DVLOG(1) << ENDPOINT << "Received message of length "
<< message.length();
QUIC_DVLOG(2) << ENDPOINT << "Contents of message of length "
<< message.length() << ":" << std::endl
<< quiche::QuicheTextUtils::HexDump(message);
}
void QuicSession::OnHandshakeDoneReceived() {
QUIC_DVLOG(1) << ENDPOINT << "OnHandshakeDoneReceived";
GetMutableCryptoStream()->OnHandshakeDoneReceived();
}
void QuicSession::OnNewTokenReceived(absl::string_view token) {
QUICHE_DCHECK_EQ(perspective_, Perspective::IS_CLIENT);
GetMutableCryptoStream()->OnNewTokenReceived(token);
}
// static
void QuicSession::RecordConnectionCloseAtServer(QuicErrorCode error,
ConnectionCloseSource source) {
if (error != QUIC_NO_ERROR) {
if (source == ConnectionCloseSource::FROM_SELF) {
QUIC_SERVER_HISTOGRAM_ENUM(
"quic_server_connection_close_errors", error, QUIC_LAST_ERROR,
"QuicErrorCode for server-closed connections.");
} else {
QUIC_SERVER_HISTOGRAM_ENUM(
"quic_client_connection_close_errors", error, QUIC_LAST_ERROR,
"QuicErrorCode for client-closed connections.");
}
}
}
void QuicSession::OnConnectionClosed(const QuicConnectionCloseFrame& frame,
ConnectionCloseSource source) {
QUICHE_DCHECK(!connection_->connected());
if (perspective() == Perspective::IS_SERVER) {
RecordConnectionCloseAtServer(frame.quic_error_code, source);
}
if (on_closed_frame_.quic_error_code == QUIC_NO_ERROR) {
// Save all of the connection close information
on_closed_frame_ = frame;
}
GetMutableCryptoStream()->OnConnectionClosed(frame.quic_error_code, source);
PerformActionOnActiveStreams([this, frame, source](QuicStream* stream) {
QuicStreamId id = stream->id();
stream->OnConnectionClosed(frame.quic_error_code, source);
auto it = stream_map_.find(id);
if (it != stream_map_.end()) {
QUIC_BUG_IF(quic_bug_12435_2, !it->second->IsZombie())
<< ENDPOINT << "Non-zombie stream " << id
<< " failed to close under OnConnectionClosed";
}
return true;
});
closed_streams_clean_up_alarm_->Cancel();
if (visitor_) {
visitor_->OnConnectionClosed(connection_->GetOneActiveServerConnectionId(),
frame.quic_error_code, frame.error_details,
source);
}
}
void QuicSession::OnWriteBlocked() {
if (!connection_->connected()) {
return;
}
if (visitor_) {
visitor_->OnWriteBlocked(connection_);
}
}
void QuicSession::OnSuccessfulVersionNegotiation(
const ParsedQuicVersion& /*version*/) {}
void QuicSession::OnPacketReceived(const QuicSocketAddress& /*self_address*/,
const QuicSocketAddress& peer_address,
bool is_connectivity_probe) {
if (is_connectivity_probe && perspective() == Perspective::IS_SERVER) {
// Server only sends back a connectivity probe after received a
// connectivity probe from a new peer address.
if (connection_->send_path_response()) {
// SendConnectivityProbingResponsePacket() will be deprecated.
// SendConnectivityProbingPacket() will be used to send both probing
// request and response as both of them are padded PING.
connection_->SendConnectivityProbingPacket(nullptr, peer_address);
} else {
connection_->SendConnectivityProbingResponsePacket(peer_address);
}
}
}
void QuicSession::OnPathDegrading() {}
void QuicSession::OnForwardProgressMadeAfterPathDegrading() {}
bool QuicSession::AllowSelfAddressChange() const { return false; }
void QuicSession::OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) {
// Stream may be closed by the time we receive a WINDOW_UPDATE, so we can't
// assume that it still exists.
QuicStreamId stream_id = frame.stream_id;
if (stream_id == QuicUtils::GetInvalidStreamId(transport_version())) {
// This is a window update that applies to the connection, rather than an
// individual stream.
QUIC_DVLOG(1) << ENDPOINT
<< "Received connection level flow control window "
"update with max data: "
<< frame.max_data;
flow_controller_.UpdateSendWindowOffset(frame.max_data);
return;
}
if (VersionHasIetfQuicFrames(transport_version()) &&
QuicUtils::GetStreamType(stream_id, perspective(),
IsIncomingStream(stream_id),
version()) == READ_UNIDIRECTIONAL) {
connection()->CloseConnection(
QUIC_WINDOW_UPDATE_RECEIVED_ON_READ_UNIDIRECTIONAL_STREAM,
"WindowUpdateFrame received on READ_UNIDIRECTIONAL stream.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (ShouldProcessFrameByPendingStream(WINDOW_UPDATE_FRAME, stream_id)) {
PendingStreamOnWindowUpdateFrame(frame);
return;
}
QuicStream* stream = GetOrCreateStream(stream_id);
if (stream != nullptr) {
stream->OnWindowUpdateFrame(frame);
}
}
void QuicSession::OnBlockedFrame(const QuicBlockedFrame& frame) {
// TODO(rjshade): Compare our flow control receive windows for specified
// streams: if we have a large window then maybe something
// had gone wrong with the flow control accounting.
QUIC_DLOG(INFO) << ENDPOINT << "Received BLOCKED frame with stream id: "
<< frame.stream_id;
}
bool QuicSession::CheckStreamNotBusyLooping(QuicStream* stream,
uint64_t previous_bytes_written,
bool previous_fin_sent) {
if ( // Stream should not be closed.
!stream->write_side_closed() &&
// Not connection flow control blocked.
!flow_controller_.IsBlocked() &&
// Detect lack of forward progress.
previous_bytes_written == stream->stream_bytes_written() &&
previous_fin_sent == stream->fin_sent()) {
stream->set_busy_counter(stream->busy_counter() + 1);
QUIC_DVLOG(1) << ENDPOINT << "Suspected busy loop on stream id "
<< stream->id() << " stream_bytes_written "
<< stream->stream_bytes_written() << " fin "
<< stream->fin_sent() << " count " << stream->busy_counter();
// Wait a few iterations before firing, the exact count is
// arbitrary, more than a few to cover a few test-only false
// positives.
if (stream->busy_counter() > 20) {
QUIC_LOG(ERROR) << ENDPOINT << "Detected busy loop on stream id "
<< stream->id() << " stream_bytes_written "
<< stream->stream_bytes_written() << " fin "
<< stream->fin_sent();
return false;
}
} else {
stream->set_busy_counter(0);
}
return true;
}
bool QuicSession::CheckStreamWriteBlocked(QuicStream* stream) const {
if (!stream->write_side_closed() && stream->HasBufferedData() &&
!stream->IsFlowControlBlocked() &&
!write_blocked_streams_.IsStreamBlocked(stream->id())) {
QUIC_DLOG(ERROR) << ENDPOINT << "stream " << stream->id()
<< " has buffered " << stream->BufferedDataBytes()
<< " bytes, and is not flow control blocked, "
"but it is not in the write block list.";
return false;
}
return true;
}
void QuicSession::OnCanWrite() {
if (connection_->framer().is_processing_packet()) {
// Do not write data in the middle of packet processing because rest
// frames in the packet may change the data to write. For example, lost
// data could be acknowledged. Also, connection is going to emit
// OnCanWrite signal post packet processing.
QUIC_BUG(session_write_mid_packet_processing)
<< ENDPOINT << "Try to write mid packet processing.";
return;
}
if (!RetransmitLostData()) {
// Cannot finish retransmitting lost data, connection is write blocked.
QUIC_DVLOG(1) << ENDPOINT
<< "Cannot finish retransmitting lost data, connection is "
"write blocked.";
return;
}
// We limit the number of writes to the number of pending streams. If more
// streams become pending, WillingAndAbleToWrite will be true, which will
// cause the connection to request resumption before yielding to other
// connections.
// If we are connection level flow control blocked, then only allow the
// crypto and headers streams to try writing as all other streams will be
// blocked.
size_t num_writes = flow_controller_.IsBlocked()
? write_blocked_streams_.NumBlockedSpecialStreams()
: write_blocked_streams_.NumBlockedStreams();
if (num_writes == 0 && !control_frame_manager_.WillingToWrite() &&
datagram_queue_.empty() &&
(!QuicVersionUsesCryptoFrames(transport_version()) ||
!GetCryptoStream()->HasBufferedCryptoFrames())) {
return;
}
QuicConnection::ScopedPacketFlusher flusher(connection_);
if (QuicVersionUsesCryptoFrames(transport_version())) {
QuicCryptoStream* crypto_stream = GetMutableCryptoStream();
if (crypto_stream->HasBufferedCryptoFrames()) {
crypto_stream->WriteBufferedCryptoFrames();
}
if (crypto_stream->HasBufferedCryptoFrames()) {
// Cannot finish writing buffered crypto frames, connection is write
// blocked.
return;
}
}
if (control_frame_manager_.WillingToWrite()) {
control_frame_manager_.OnCanWrite();
}
// TODO(b/147146815): this makes all datagrams go before stream data. We
// should have a better priority scheme for this.
if (!datagram_queue_.empty()) {
size_t written = datagram_queue_.SendDatagrams();
QUIC_DVLOG(1) << ENDPOINT << "Sent " << written << " datagrams";
if (!datagram_queue_.empty()) {
return;
}
}
std::vector<QuicStreamId> last_writing_stream_ids;
for (size_t i = 0; i < num_writes; ++i) {
if (!(write_blocked_streams_.HasWriteBlockedSpecialStream() ||
write_blocked_streams_.HasWriteBlockedDataStreams())) {
// Writing one stream removed another!? Something's broken.
QUIC_BUG(quic_bug_10866_1)
<< "WriteBlockedStream is missing, num_writes: " << num_writes
<< ", finished_writes: " << i
<< ", connected: " << connection_->connected()
<< ", connection level flow control blocked: "
<< flow_controller_.IsBlocked();
for (QuicStreamId id : last_writing_stream_ids) {
QUIC_LOG(WARNING) << "last_writing_stream_id: " << id;
}
connection_->CloseConnection(QUIC_INTERNAL_ERROR,
"WriteBlockedStream is missing",
ConnectionCloseBehavior::SILENT_CLOSE);
return;
}
if (!CanWriteStreamData()) {
return;
}
currently_writing_stream_id_ = write_blocked_streams_.PopFront();
last_writing_stream_ids.push_back(currently_writing_stream_id_);
QUIC_DVLOG(1) << ENDPOINT << "Removing stream "
<< currently_writing_stream_id_ << " from write-blocked list";
QuicStream* stream = GetOrCreateStream(currently_writing_stream_id_);
if (stream != nullptr && !stream->IsFlowControlBlocked()) {
// If the stream can't write all bytes it'll re-add itself to the blocked
// list.
uint64_t previous_bytes_written = stream->stream_bytes_written();
bool previous_fin_sent = stream->fin_sent();
QUIC_DVLOG(1) << ENDPOINT << "stream " << stream->id()
<< " bytes_written " << previous_bytes_written << " fin "
<< previous_fin_sent;
stream->OnCanWrite();
QUICHE_DCHECK(CheckStreamWriteBlocked(stream));
QUICHE_DCHECK(CheckStreamNotBusyLooping(stream, previous_bytes_written,
previous_fin_sent));
}
currently_writing_stream_id_ = 0;
}
}
bool QuicSession::SendProbingData() {
if (connection()->sent_packet_manager().MaybeRetransmitOldestPacket(
PROBING_RETRANSMISSION)) {
return true;
}
return false;
}
bool QuicSession::WillingAndAbleToWrite() const {
// Schedule a write when:
// 1) control frame manager has pending or new control frames, or
// 2) any stream has pending retransmissions, or
// 3) If the crypto or headers streams are blocked, or
// 4) connection is not flow control blocked and there are write blocked
// streams.
if (QuicVersionUsesCryptoFrames(transport_version())) {
if (HasPendingHandshake()) {
return true;
}
if (!IsEncryptionEstablished()) {
return false;
}
}
if (control_frame_manager_.WillingToWrite() ||
!streams_with_pending_retransmission_.empty()) {
return true;
}
if (flow_controller_.IsBlocked()) {
if (VersionUsesHttp3(transport_version())) {
return false;
}
// Crypto and headers streams are not blocked by connection level flow
// control.
return write_blocked_streams_.HasWriteBlockedSpecialStream();
}
return write_blocked_streams_.HasWriteBlockedSpecialStream() ||
write_blocked_streams_.HasWriteBlockedDataStreams();
}
std::string QuicSession::GetStreamsInfoForLogging() const {
std::string info = absl::StrCat(
"num_active_streams: ", GetNumActiveStreams(),
", num_pending_streams: ", pending_streams_size(),
", num_outgoing_draining_streams: ", num_outgoing_draining_streams(),
" ");
// Log info for up to 5 streams.
size_t i = 5;
for (const auto& it : stream_map_) {
if (it.second->is_static()) {
continue;
}
// Calculate the stream creation delay.
const QuicTime::Delta delay =
connection_->clock()->ApproximateNow() - it.second->creation_time();
absl::StrAppend(
&info, "{", it.second->id(), ":", delay.ToDebuggingValue(), ";",
it.second->stream_bytes_written(), ",", it.second->fin_sent(), ",",
it.second->HasBufferedData(), ",", it.second->fin_buffered(), ";",
it.second->stream_bytes_read(), ",", it.second->fin_received(), "}");
--i;
if (i == 0) {
break;
}
}
return info;
}
bool QuicSession::HasPendingHandshake() const {
if (QuicVersionUsesCryptoFrames(transport_version())) {
return GetCryptoStream()->HasPendingCryptoRetransmission() ||
GetCryptoStream()->HasBufferedCryptoFrames();
}
return streams_with_pending_retransmission_.contains(
QuicUtils::GetCryptoStreamId(transport_version())) ||
write_blocked_streams_.IsStreamBlocked(
QuicUtils::GetCryptoStreamId(transport_version()));
}
void QuicSession::ProcessUdpPacket(const QuicSocketAddress& self_address,
const QuicSocketAddress& peer_address,
const QuicReceivedPacket& packet) {
QuicConnectionContextSwitcher cs(connection_->context());
connection_->ProcessUdpPacket(self_address, peer_address, packet);
}
QuicConsumedData QuicSession::WritevData(QuicStreamId id, size_t write_length,
QuicStreamOffset offset,
StreamSendingState state,
TransmissionType type,
EncryptionLevel level) {
QUICHE_DCHECK(connection_->connected())
<< ENDPOINT << "Try to write stream data when connection is closed.";
if (!IsEncryptionEstablished() &&
!QuicUtils::IsCryptoStreamId(transport_version(), id)) {
// Do not let streams write without encryption. The calling stream will end
// up write blocked until OnCanWrite is next called.
if (was_zero_rtt_rejected_ && !OneRttKeysAvailable()) {
QUICHE_DCHECK(version().UsesTls() &&
perspective() == Perspective::IS_CLIENT);
QUIC_DLOG(INFO) << ENDPOINT
<< "Suppress the write while 0-RTT gets rejected and "
"1-RTT keys are not available. Version: "
<< ParsedQuicVersionToString(version());
} else if (version().UsesTls() || perspective() == Perspective::IS_SERVER) {
QUIC_BUG(quic_bug_10866_2)
<< ENDPOINT << "Try to send data of stream " << id
<< " before encryption is established. Version: "
<< ParsedQuicVersionToString(version());
} else {
// In QUIC crypto, this could happen when the client sends full CHLO and
// 0-RTT request, then receives an inchoate REJ and sends an inchoate
// CHLO. The client then gets the ACK of the inchoate CHLO or the client
// gets the full REJ and needs to verify the proof (before it sends the
// full CHLO), such that there is no outstanding crypto data.
// Retransmission alarm fires in TLP mode which tries to retransmit the
// 0-RTT request (without encryption).
QUIC_DLOG(INFO) << ENDPOINT << "Try to send data of stream " << id
<< " before encryption is established.";
}
return QuicConsumedData(0, false);
}
SetTransmissionType(type);
QuicConnection::ScopedEncryptionLevelContext context(connection(), level);
QuicConsumedData data =
connection_->SendStreamData(id, write_length, offset, state);
if (type == NOT_RETRANSMISSION) {
// This is new stream data.
write_blocked_streams_.UpdateBytesForStream(id, data.bytes_consumed);
}
return data;
}
size_t QuicSession::SendCryptoData(EncryptionLevel level, size_t write_length,
QuicStreamOffset offset,
TransmissionType type) {
QUICHE_DCHECK(QuicVersionUsesCryptoFrames(transport_version()));
if (!connection()->framer().HasEncrypterOfEncryptionLevel(level)) {
const std::string error_details = absl::StrCat(
"Try to send crypto data with missing keys of encryption level: ",
EncryptionLevelToString(level));
QUIC_BUG(quic_bug_10866_3) << ENDPOINT << error_details;
connection()->CloseConnection(
QUIC_MISSING_WRITE_KEYS, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return 0;
}
SetTransmissionType(type);
QuicConnection::ScopedEncryptionLevelContext context(connection(), level);
const auto bytes_consumed =
connection_->SendCryptoData(level, write_length, offset);
return bytes_consumed;
}
void QuicSession::OnControlFrameManagerError(QuicErrorCode error_code,
std::string error_details) {
connection_->CloseConnection(
error_code, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
bool QuicSession::WriteControlFrame(const QuicFrame& frame,
TransmissionType type) {
QUICHE_DCHECK(connection()->connected())
<< ENDPOINT << "Try to write control frames when connection is closed.";
if (!IsEncryptionEstablished()) {
// Suppress the write before encryption gets established.
return false;
}
SetTransmissionType(type);
QuicConnection::ScopedEncryptionLevelContext context(
connection(), GetEncryptionLevelToSendApplicationData());
return connection_->SendControlFrame(frame);
}
void QuicSession::ResetStream(QuicStreamId id, QuicRstStreamErrorCode error) {
QuicStream* stream = GetStream(id);
if (stream != nullptr && stream->is_static()) {
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Try to reset a static stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (stream != nullptr) {
stream->Reset(error);
return;
}
QuicConnection::ScopedPacketFlusher flusher(connection());
MaybeSendStopSendingFrame(id, QuicResetStreamError::FromInternal(error));
MaybeSendRstStreamFrame(id, QuicResetStreamError::FromInternal(error), 0);
}
void QuicSession::MaybeSendRstStreamFrame(QuicStreamId id,
QuicResetStreamError error,
QuicStreamOffset bytes_written) {
if (!connection()->connected()) {
return;
}
if (!VersionHasIetfQuicFrames(transport_version()) ||
QuicUtils::GetStreamType(id, perspective(), IsIncomingStream(id),
version()) != READ_UNIDIRECTIONAL) {
control_frame_manager_.WriteOrBufferRstStream(id, error, bytes_written);
}
connection_->OnStreamReset(id, error.internal_code());
}
void QuicSession::MaybeSendStopSendingFrame(QuicStreamId id,
QuicResetStreamError error) {
if (!connection()->connected()) {
return;
}
if (VersionHasIetfQuicFrames(transport_version()) &&
QuicUtils::GetStreamType(id, perspective(), IsIncomingStream(id),
version()) != WRITE_UNIDIRECTIONAL) {
control_frame_manager_.WriteOrBufferStopSending(error, id);
}
}
void QuicSession::SendGoAway(QuicErrorCode error_code,
const std::string& reason) {
// GOAWAY frame is not supported in IETF QUIC.
QUICHE_DCHECK(!VersionHasIetfQuicFrames(transport_version()));
if (!IsEncryptionEstablished()) {
QUIC_CODE_COUNT(quic_goaway_before_encryption_established);
connection_->CloseConnection(
error_code, reason,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (transport_goaway_sent_) {
return;
}
transport_goaway_sent_ = true;
QUICHE_DCHECK_EQ(perspective(), Perspective::IS_SERVER);
control_frame_manager_.WriteOrBufferGoAway(
error_code,
QuicUtils::GetMaxClientInitiatedBidirectionalStreamId(
transport_version()),
reason);
}
void QuicSession::SendBlocked(QuicStreamId id) {
control_frame_manager_.WriteOrBufferBlocked(id);
}
void QuicSession::SendWindowUpdate(QuicStreamId id,
QuicStreamOffset byte_offset) {
control_frame_manager_.WriteOrBufferWindowUpdate(id, byte_offset);
}
void QuicSession::OnStreamError(QuicErrorCode error_code,
std::string error_details) {
connection_->CloseConnection(
error_code, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
void QuicSession::OnStreamError(QuicErrorCode error_code,
QuicIetfTransportErrorCodes ietf_error,
std::string error_details) {
connection_->CloseConnection(
error_code, ietf_error, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
void QuicSession::SendMaxStreams(QuicStreamCount stream_count,
bool unidirectional) {
if (!is_configured_) {
QUIC_BUG(quic_bug_10866_5)
<< "Try to send max streams before config negotiated.";
return;
}
control_frame_manager_.WriteOrBufferMaxStreams(stream_count, unidirectional);
}
void QuicSession::InsertLocallyClosedStreamsHighestOffset(
const QuicStreamId id, QuicStreamOffset offset) {
locally_closed_streams_highest_offset_[id] = offset;
}
void QuicSession::OnStreamClosed(QuicStreamId stream_id) {
QUIC_DVLOG(1) << ENDPOINT << "Closing stream: " << stream_id;
StreamMap::iterator it = stream_map_.find(stream_id);
if (it == stream_map_.end()) {
QUIC_BUG(quic_bug_10866_6)
<< ENDPOINT << "Stream is already closed: " << stream_id;
return;
}
QuicStream* stream = it->second.get();
StreamType type = stream->type();
const bool stream_waiting_for_acks = stream->IsWaitingForAcks();
if (stream_waiting_for_acks) {
// The stream needs to be kept alive because it's waiting for acks.
++num_zombie_streams_;
} else {
closed_streams_.push_back(std::move(it->second));
stream_map_.erase(it);
// Do not retransmit data of a closed stream.
streams_with_pending_retransmission_.erase(stream_id);
if (!closed_streams_clean_up_alarm_->IsSet()) {
closed_streams_clean_up_alarm_->Set(
connection_->clock()->ApproximateNow());
}
QUIC_BUG_IF(
364846171_1,
connection_->packet_creator().HasPendingStreamFramesOfStream(stream_id))
<< "Stream " << stream_id
<< " gets closed while there are pending frames.";
}
if (!stream->HasReceivedFinalOffset()) {
// If we haven't received a FIN or RST for this stream, we need to keep
// track of the how many bytes the stream's flow controller believes it has
// received, for accurate connection level flow control accounting.
// If this is an outgoing stream, it is technically open from peer's
// perspective. Do not inform stream Id manager yet.
QUICHE_DCHECK(!stream->was_draining());
InsertLocallyClosedStreamsHighestOffset(
stream_id, stream->highest_received_byte_offset());
return;
}
const bool stream_was_draining = stream->was_draining();
QUIC_DVLOG_IF(1, stream_was_draining)
<< ENDPOINT << "Stream " << stream_id << " was draining";
if (stream_was_draining) {
QUIC_BUG_IF(quic_bug_12435_4, num_draining_streams_ == 0);
--num_draining_streams_;
if (!IsIncomingStream(stream_id)) {
QUIC_BUG_IF(quic_bug_12435_5, num_outgoing_draining_streams_ == 0);
--num_outgoing_draining_streams_;
}
// Stream Id manager has been informed with draining streams.
return;
}
if (!VersionHasIetfQuicFrames(transport_version())) {
stream_id_manager_.OnStreamClosed(
/*is_incoming=*/IsIncomingStream(stream_id));
}
if (!connection_->connected()) {
return;
}
if (IsIncomingStream(stream_id)) {
// Stream Id manager is only interested in peer initiated stream IDs.
if (VersionHasIetfQuicFrames(transport_version())) {
ietf_streamid_manager_.OnStreamClosed(stream_id);
}
return;
}
if (!VersionHasIetfQuicFrames(transport_version())) {
OnCanCreateNewOutgoingStream(type != BIDIRECTIONAL);
}
}
void QuicSession::ClosePendingStream(QuicStreamId stream_id) {
QUIC_DVLOG(1) << ENDPOINT << "Closing stream " << stream_id;
QUICHE_DCHECK(VersionHasIetfQuicFrames(transport_version()));
pending_stream_map_.erase(stream_id);
if (connection_->connected()) {
ietf_streamid_manager_.OnStreamClosed(stream_id);
}
}
bool QuicSession::ShouldProcessFrameByPendingStream(QuicFrameType type,
QuicStreamId id) const {
return UsesPendingStreamForFrame(type, id) &&
stream_map_.find(id) == stream_map_.end();
}
void QuicSession::OnFinalByteOffsetReceived(
QuicStreamId stream_id, QuicStreamOffset final_byte_offset) {
auto it = locally_closed_streams_highest_offset_.find(stream_id);
if (it == locally_closed_streams_highest_offset_.end()) {
return;
}
QUIC_DVLOG(1) << ENDPOINT << "Received final byte offset "
<< final_byte_offset << " for stream " << stream_id;
QuicByteCount offset_diff = final_byte_offset - it->second;
if (flow_controller_.UpdateHighestReceivedOffset(
flow_controller_.highest_received_byte_offset() + offset_diff)) {
// If the final offset violates flow control, close the connection now.
if (flow_controller_.FlowControlViolation()) {
connection_->CloseConnection(
QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA,
"Connection level flow control violation",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
}
flow_controller_.AddBytesConsumed(offset_diff);
locally_closed_streams_highest_offset_.erase(it);
if (!VersionHasIetfQuicFrames(transport_version())) {
stream_id_manager_.OnStreamClosed(
/*is_incoming=*/IsIncomingStream(stream_id));
}
if (IsIncomingStream(stream_id)) {
if (VersionHasIetfQuicFrames(transport_version())) {
ietf_streamid_manager_.OnStreamClosed(stream_id);
}
} else if (!VersionHasIetfQuicFrames(transport_version())) {
OnCanCreateNewOutgoingStream(false);
}
}
bool QuicSession::IsEncryptionEstablished() const {
if (GetCryptoStream() == nullptr) {
return false;
}
return GetCryptoStream()->encryption_established();
}
bool QuicSession::OneRttKeysAvailable() const {
if (GetCryptoStream() == nullptr) {
return false;
}
return GetCryptoStream()->one_rtt_keys_available();
}
void QuicSession::OnConfigNegotiated() {
// In versions with TLS, the configs will be set twice if 0-RTT is available.
// In the second config setting, 1-RTT keys are guaranteed to be available.
if (version().UsesTls() && is_configured_ &&
connection_->encryption_level() != ENCRYPTION_FORWARD_SECURE) {
QUIC_BUG(quic_bug_12435_6)
<< ENDPOINT
<< "1-RTT keys missing when config is negotiated for the second time.";
connection_->CloseConnection(
QUIC_INTERNAL_ERROR,
"1-RTT keys missing when config is negotiated for the second time.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
QUIC_DVLOG(1) << ENDPOINT << "OnConfigNegotiated";
connection_->SetFromConfig(config_);
if (VersionHasIetfQuicFrames(transport_version())) {
uint32_t max_streams = 0;
if (config_.HasReceivedMaxBidirectionalStreams()) {
max_streams = config_.ReceivedMaxBidirectionalStreams();
}
if (was_zero_rtt_rejected_ &&
max_streams <
ietf_streamid_manager_.outgoing_bidirectional_stream_count()) {
connection_->CloseConnection(
QUIC_ZERO_RTT_UNRETRANSMITTABLE,
absl::StrCat(
"Server rejected 0-RTT, aborting because new bidirectional "
"initial stream limit ",
max_streams, " is less than current open streams: ",
ietf_streamid_manager_.outgoing_bidirectional_stream_count()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
QUIC_DVLOG(1) << ENDPOINT
<< "Setting Bidirectional outgoing_max_streams_ to "
<< max_streams;
if (perspective_ == Perspective::IS_CLIENT &&
max_streams <
ietf_streamid_manager_.max_outgoing_bidirectional_streams()) {
connection_->CloseConnection(
was_zero_rtt_rejected_ ? QUIC_ZERO_RTT_REJECTION_LIMIT_REDUCED
: QUIC_ZERO_RTT_RESUMPTION_LIMIT_REDUCED,
absl::StrCat(
was_zero_rtt_rejected_
? "Server rejected 0-RTT, aborting because "
: "",
"new bidirectional limit ", max_streams,
" decreases the current limit: ",
ietf_streamid_manager_.max_outgoing_bidirectional_streams()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (ietf_streamid_manager_.MaybeAllowNewOutgoingBidirectionalStreams(
max_streams)) {
OnCanCreateNewOutgoingStream(/*unidirectional = */ false);
}
max_streams = 0;
if (config_.HasReceivedMaxUnidirectionalStreams()) {
max_streams = config_.ReceivedMaxUnidirectionalStreams();
}
if (was_zero_rtt_rejected_ &&
max_streams <
ietf_streamid_manager_.outgoing_unidirectional_stream_count()) {
connection_->CloseConnection(
QUIC_ZERO_RTT_UNRETRANSMITTABLE,
absl::StrCat(
"Server rejected 0-RTT, aborting because new unidirectional "
"initial stream limit ",
max_streams, " is less than current open streams: ",
ietf_streamid_manager_.outgoing_unidirectional_stream_count()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (max_streams <
ietf_streamid_manager_.max_outgoing_unidirectional_streams()) {
connection_->CloseConnection(
was_zero_rtt_rejected_ ? QUIC_ZERO_RTT_REJECTION_LIMIT_REDUCED
: QUIC_ZERO_RTT_RESUMPTION_LIMIT_REDUCED,
absl::StrCat(
was_zero_rtt_rejected_
? "Server rejected 0-RTT, aborting because "
: "",
"new unidirectional limit ", max_streams,
" decreases the current limit: ",
ietf_streamid_manager_.max_outgoing_unidirectional_streams()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
QUIC_DVLOG(1) << ENDPOINT
<< "Setting Unidirectional outgoing_max_streams_ to "
<< max_streams;
if (ietf_streamid_manager_.MaybeAllowNewOutgoingUnidirectionalStreams(
max_streams)) {
OnCanCreateNewOutgoingStream(/*unidirectional = */ true);
}
} else {
uint32_t max_streams = 0;
if (config_.HasReceivedMaxBidirectionalStreams()) {
max_streams = config_.ReceivedMaxBidirectionalStreams();
}
QUIC_DVLOG(1) << ENDPOINT << "Setting max_open_outgoing_streams_ to "
<< max_streams;
if (was_zero_rtt_rejected_ &&
max_streams < stream_id_manager_.num_open_outgoing_streams()) {
connection_->CloseConnection(
QUIC_INTERNAL_ERROR,
absl::StrCat(
"Server rejected 0-RTT, aborting because new stream limit ",
max_streams, " is less than current open streams: ",
stream_id_manager_.num_open_outgoing_streams()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
stream_id_manager_.set_max_open_outgoing_streams(max_streams);
}
if (perspective() == Perspective::IS_SERVER) {
if (config_.HasReceivedConnectionOptions()) {
// The following variations change the initial receive flow control
// window sizes.
if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW6)) {
AdjustInitialFlowControlWindows(64 * 1024);
}
if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW7)) {
AdjustInitialFlowControlWindows(128 * 1024);
}
if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW8)) {
AdjustInitialFlowControlWindows(256 * 1024);
}
if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFW9)) {
AdjustInitialFlowControlWindows(512 * 1024);
}
if (ContainsQuicTag(config_.ReceivedConnectionOptions(), kIFWA)) {
AdjustInitialFlowControlWindows(1024 * 1024);
}
}
config_.SetStatelessResetTokenToSend(GetStatelessResetToken());
}
if (VersionHasIetfQuicFrames(transport_version())) {
ietf_streamid_manager_.SetMaxOpenIncomingBidirectionalStreams(
config_.GetMaxBidirectionalStreamsToSend());
ietf_streamid_manager_.SetMaxOpenIncomingUnidirectionalStreams(
config_.GetMaxUnidirectionalStreamsToSend());
} else {
// A small number of additional incoming streams beyond the limit should be
// allowed. This helps avoid early connection termination when FIN/RSTs for
// old streams are lost or arrive out of order.
// Use a minimum number of additional streams, or a percentage increase,
// whichever is larger.
uint32_t max_incoming_streams_to_send =
config_.GetMaxBidirectionalStreamsToSend();
uint32_t max_incoming_streams =
std::max(max_incoming_streams_to_send + kMaxStreamsMinimumIncrement,
static_cast<uint32_t>(max_incoming_streams_to_send *
kMaxStreamsMultiplier));
stream_id_manager_.set_max_open_incoming_streams(max_incoming_streams);
}
if (connection_->version().handshake_protocol == PROTOCOL_TLS1_3) {
// When using IETF-style TLS transport parameters, inform existing streams
// of new flow-control limits.
if (config_.HasReceivedInitialMaxStreamDataBytesOutgoingBidirectional()) {
OnNewStreamOutgoingBidirectionalFlowControlWindow(
config_.ReceivedInitialMaxStreamDataBytesOutgoingBidirectional());
}
if (config_.HasReceivedInitialMaxStreamDataBytesIncomingBidirectional()) {
OnNewStreamIncomingBidirectionalFlowControlWindow(
config_.ReceivedInitialMaxStreamDataBytesIncomingBidirectional());
}
if (config_.HasReceivedInitialMaxStreamDataBytesUnidirectional()) {
OnNewStreamUnidirectionalFlowControlWindow(
config_.ReceivedInitialMaxStreamDataBytesUnidirectional());
}
} else { // The version uses Google QUIC Crypto.
if (config_.HasReceivedInitialStreamFlowControlWindowBytes()) {
// Streams which were created before the SHLO was received (0-RTT
// requests) are now informed of the peer's initial flow control window.
OnNewStreamFlowControlWindow(
config_.ReceivedInitialStreamFlowControlWindowBytes());
}
}
if (config_.HasReceivedInitialSessionFlowControlWindowBytes()) {
OnNewSessionFlowControlWindow(
config_.ReceivedInitialSessionFlowControlWindowBytes());
}
is_configured_ = true;
connection()->OnConfigNegotiated();
// Ask flow controllers to try again since the config could have unblocked us.
// Or if this session is configured on TLS enabled QUIC versions,
// attempt to retransmit 0-RTT data if there's any.
// TODO(fayang): consider removing this OnCanWrite call.
if (!connection_->framer().is_processing_packet() &&
(connection_->version().AllowsLowFlowControlLimits() ||
version().UsesTls())) {
QUIC_CODE_COUNT(quic_session_on_can_write_on_config_negotiated);
OnCanWrite();
}
}
absl::optional<std::string> QuicSession::OnAlpsData(
const uint8_t* /*alps_data*/, size_t /*alps_length*/) {
return absl::nullopt;
}
void QuicSession::AdjustInitialFlowControlWindows(size_t stream_window) {
const float session_window_multiplier =
config_.GetInitialStreamFlowControlWindowToSend()
? static_cast<float>(
config_.GetInitialSessionFlowControlWindowToSend()) /
config_.GetInitialStreamFlowControlWindowToSend()
: 1.5;
QUIC_DVLOG(1) << ENDPOINT << "Set stream receive window to " << stream_window;
config_.SetInitialStreamFlowControlWindowToSend(stream_window);
size_t session_window = session_window_multiplier * stream_window;
QUIC_DVLOG(1) << ENDPOINT << "Set session receive window to "
<< session_window;
config_.SetInitialSessionFlowControlWindowToSend(session_window);
flow_controller_.UpdateReceiveWindowSize(session_window);
// Inform all existing streams about the new window.
for (auto const& kv : stream_map_) {
kv.second->UpdateReceiveWindowSize(stream_window);
}
if (!QuicVersionUsesCryptoFrames(transport_version())) {
GetMutableCryptoStream()->UpdateReceiveWindowSize(stream_window);
}
}
void QuicSession::HandleFrameOnNonexistentOutgoingStream(
QuicStreamId stream_id) {
QUICHE_DCHECK(!IsClosedStream(stream_id));
// Received a frame for a locally-created stream that is not currently
// active. This is an error.
if (VersionHasIetfQuicFrames(transport_version())) {
connection()->CloseConnection(
QUIC_HTTP_STREAM_WRONG_DIRECTION, "Data for nonexistent stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, "Data for nonexistent stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
void QuicSession::HandleRstOnValidNonexistentStream(
const QuicRstStreamFrame& frame) {
// If the stream is neither originally in active streams nor created in
// GetOrCreateStream(), it could be a closed stream in which case its
// final received byte offset need to be updated.
if (IsClosedStream(frame.stream_id)) {
// The RST frame contains the final byte offset for the stream: we can now
// update the connection level flow controller if needed.
OnFinalByteOffsetReceived(frame.stream_id, frame.byte_offset);
}
}
void QuicSession::OnNewStreamFlowControlWindow(QuicStreamOffset new_window) {
QUICHE_DCHECK(version().UsesQuicCrypto());
QUIC_DVLOG(1) << ENDPOINT << "OnNewStreamFlowControlWindow " << new_window;
if (new_window < kMinimumFlowControlSendWindow) {
QUIC_LOG_FIRST_N(ERROR, 1)
<< "Peer sent us an invalid stream flow control send window: "
<< new_window << ", below minimum: " << kMinimumFlowControlSendWindow;
connection_->CloseConnection(
QUIC_FLOW_CONTROL_INVALID_WINDOW, "New stream window too low",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
// Inform all existing streams about the new window.
for (auto const& kv : stream_map_) {
QUIC_DVLOG(1) << ENDPOINT << "Informing stream " << kv.first
<< " of new stream flow control window " << new_window;
if (!kv.second->MaybeConfigSendWindowOffset(
new_window, /* was_zero_rtt_rejected = */ false)) {
return;
}
}
if (!QuicVersionUsesCryptoFrames(transport_version())) {
QUIC_DVLOG(1)
<< ENDPOINT
<< "Informing crypto stream of new stream flow control window "
<< new_window;
GetMutableCryptoStream()->MaybeConfigSendWindowOffset(
new_window, /* was_zero_rtt_rejected = */ false);
}
}
void QuicSession::OnNewStreamUnidirectionalFlowControlWindow(
QuicStreamOffset new_window) {
QUICHE_DCHECK_EQ(connection_->version().handshake_protocol, PROTOCOL_TLS1_3);
QUIC_DVLOG(1) << ENDPOINT << "OnNewStreamUnidirectionalFlowControlWindow "
<< new_window;
// Inform all existing outgoing unidirectional streams about the new window.
for (auto const& kv : stream_map_) {
const QuicStreamId id = kv.first;
if (!version().HasIetfQuicFrames()) {
if (kv.second->type() == BIDIRECTIONAL) {
continue;
}
} else {
if (QuicUtils::IsBidirectionalStreamId(id, version())) {
continue;
}
}
if (!QuicUtils::IsOutgoingStreamId(connection_->version(), id,
perspective())) {
continue;
}
QUIC_DVLOG(1) << ENDPOINT << "Informing unidirectional stream " << id
<< " of new stream flow control window " << new_window;
if (!kv.second->MaybeConfigSendWindowOffset(new_window,
was_zero_rtt_rejected_)) {
return;
}
}
}
void QuicSession::OnNewStreamOutgoingBidirectionalFlowControlWindow(
QuicStreamOffset new_window) {
QUICHE_DCHECK_EQ(connection_->version().handshake_protocol, PROTOCOL_TLS1_3);
QUIC_DVLOG(1) << ENDPOINT
<< "OnNewStreamOutgoingBidirectionalFlowControlWindow "
<< new_window;
// Inform all existing outgoing bidirectional streams about the new window.
for (auto const& kv : stream_map_) {
const QuicStreamId id = kv.first;
if (!version().HasIetfQuicFrames()) {
if (kv.second->type() != BIDIRECTIONAL) {
continue;
}
} else {
if (!QuicUtils::IsBidirectionalStreamId(id, version())) {
continue;
}
}
if (!QuicUtils::IsOutgoingStreamId(connection_->version(), id,
perspective())) {
continue;
}
QUIC_DVLOG(1) << ENDPOINT << "Informing outgoing bidirectional stream "
<< id << " of new stream flow control window " << new_window;
if (!kv.second->MaybeConfigSendWindowOffset(new_window,
was_zero_rtt_rejected_)) {
return;
}
}
}
void QuicSession::OnNewStreamIncomingBidirectionalFlowControlWindow(
QuicStreamOffset new_window) {
QUICHE_DCHECK_EQ(connection_->version().handshake_protocol, PROTOCOL_TLS1_3);
QUIC_DVLOG(1) << ENDPOINT
<< "OnNewStreamIncomingBidirectionalFlowControlWindow "
<< new_window;
// Inform all existing incoming bidirectional streams about the new window.
for (auto const& kv : stream_map_) {
const QuicStreamId id = kv.first;
if (!version().HasIetfQuicFrames()) {
if (kv.second->type() != BIDIRECTIONAL) {
continue;
}
} else {
if (!QuicUtils::IsBidirectionalStreamId(id, version())) {
continue;
}
}
if (QuicUtils::IsOutgoingStreamId(connection_->version(), id,
perspective())) {
continue;
}
QUIC_DVLOG(1) << ENDPOINT << "Informing incoming bidirectional stream "
<< id << " of new stream flow control window " << new_window;
if (!kv.second->MaybeConfigSendWindowOffset(new_window,
was_zero_rtt_rejected_)) {
return;
}
}
}
void QuicSession::OnNewSessionFlowControlWindow(QuicStreamOffset new_window) {
QUIC_DVLOG(1) << ENDPOINT << "OnNewSessionFlowControlWindow " << new_window;
if (was_zero_rtt_rejected_ && new_window < flow_controller_.bytes_sent()) {
std::string error_details = absl::StrCat(
"Server rejected 0-RTT. Aborting because the client received session "
"flow control send window: ",
new_window,
", which is below currently used: ", flow_controller_.bytes_sent());
QUIC_LOG(ERROR) << error_details;
connection_->CloseConnection(
QUIC_ZERO_RTT_UNRETRANSMITTABLE, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (!connection_->version().AllowsLowFlowControlLimits() &&
new_window < kMinimumFlowControlSendWindow) {
std::string error_details = absl::StrCat(
"Peer sent us an invalid session flow control send window: ",
new_window, ", below minimum: ", kMinimumFlowControlSendWindow);
QUIC_LOG_FIRST_N(ERROR, 1) << error_details;
connection_->CloseConnection(
QUIC_FLOW_CONTROL_INVALID_WINDOW, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
if (perspective_ == Perspective::IS_CLIENT &&
new_window < flow_controller_.send_window_offset()) {
// The client receives a lower limit than remembered, violating
// https://tools.ietf.org/html/draft-ietf-quic-transport-27#section-7.3.1
std::string error_details = absl::StrCat(
was_zero_rtt_rejected_ ? "Server rejected 0-RTT, aborting because "
: "",
"new session max data ", new_window,
" decreases current limit: ", flow_controller_.send_window_offset());
QUIC_LOG(ERROR) << error_details;
connection_->CloseConnection(
was_zero_rtt_rejected_ ? QUIC_ZERO_RTT_REJECTION_LIMIT_REDUCED
: QUIC_ZERO_RTT_RESUMPTION_LIMIT_REDUCED,
error_details, ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
flow_controller_.UpdateSendWindowOffset(new_window);
}
bool QuicSession::OnNewDecryptionKeyAvailable(
EncryptionLevel level, std::unique_ptr<QuicDecrypter> decrypter,
bool set_alternative_decrypter, bool latch_once_used) {
if (connection_->version().handshake_protocol == PROTOCOL_TLS1_3 &&
!connection()->framer().HasEncrypterOfEncryptionLevel(
QuicUtils::GetEncryptionLevel(
QuicUtils::GetPacketNumberSpace(level)))) {
// This should never happen because connection should never decrypt a packet
// while an ACK for it cannot be encrypted.
return false;
}
if (connection()->version().KnowsWhichDecrypterToUse()) {
connection()->InstallDecrypter(level, std::move(decrypter));
return true;
}
if (set_alternative_decrypter) {
connection()->SetAlternativeDecrypter(level, std::move(decrypter),
latch_once_used);
return true;
}
connection()->SetDecrypter(level, std::move(decrypter));
return true;
}
void QuicSession::OnNewEncryptionKeyAvailable(
EncryptionLevel level, std::unique_ptr<QuicEncrypter> encrypter) {
connection()->SetEncrypter(level, std::move(encrypter));
if (connection_->version().handshake_protocol != PROTOCOL_TLS1_3) {
return;
}
bool reset_encryption_level = false;
if (IsEncryptionEstablished() && level == ENCRYPTION_HANDSHAKE) {
// ENCRYPTION_HANDSHAKE keys are only used for the handshake. If
// ENCRYPTION_ZERO_RTT keys exist, it is possible for a client to send
// stream data, which must not be sent at the ENCRYPTION_HANDSHAKE level.
// Therefore, we avoid setting the default encryption level to
// ENCRYPTION_HANDSHAKE.
reset_encryption_level = true;
}
QUIC_DVLOG(1) << ENDPOINT << "Set default encryption level to " << level;
connection()->SetDefaultEncryptionLevel(level);
if (reset_encryption_level) {
connection()->SetDefaultEncryptionLevel(ENCRYPTION_ZERO_RTT);
}
QUIC_BUG_IF(quic_bug_12435_7,
IsEncryptionEstablished() &&
(connection()->encryption_level() == ENCRYPTION_INITIAL ||
connection()->encryption_level() == ENCRYPTION_HANDSHAKE))
<< "Encryption is established, but the encryption level " << level
<< " does not support sending stream data";
}
void QuicSession::SetDefaultEncryptionLevel(EncryptionLevel level) {
QUICHE_DCHECK_EQ(PROTOCOL_QUIC_CRYPTO,
connection_->version().handshake_protocol);
QUIC_DVLOG(1) << ENDPOINT << "Set default encryption level to " << level;
connection()->SetDefaultEncryptionLevel(level);
switch (level) {
case ENCRYPTION_INITIAL:
break;
case ENCRYPTION_ZERO_RTT:
if (perspective() == Perspective::IS_CLIENT) {
// Retransmit old 0-RTT data (if any) with the new 0-RTT keys, since
// they can't be decrypted by the server.
connection_->MarkZeroRttPacketsForRetransmission(0);
if (!connection_->framer().is_processing_packet()) {
// TODO(fayang): consider removing this OnCanWrite call.
// Given any streams blocked by encryption a chance to write.
QUIC_CODE_COUNT(
quic_session_on_can_write_set_default_encryption_level);
OnCanWrite();
}
}
break;
case ENCRYPTION_HANDSHAKE:
break;
case ENCRYPTION_FORWARD_SECURE:
QUIC_BUG_IF(quic_bug_12435_8, !config_.negotiated())
<< ENDPOINT << "Handshake confirmed without parameter negotiation.";
connection()->mutable_stats().handshake_completion_time =
connection()->clock()->ApproximateNow();
break;
default:
QUIC_BUG(quic_bug_10866_7) << "Unknown encryption level: " << level;
}
}
void QuicSession::OnTlsHandshakeComplete() {
QUICHE_DCHECK_EQ(PROTOCOL_TLS1_3, connection_->version().handshake_protocol);
QUIC_BUG_IF(quic_bug_12435_9,
!GetCryptoStream()->crypto_negotiated_params().cipher_suite)
<< ENDPOINT << "Handshake completes without cipher suite negotiation.";
QUIC_BUG_IF(quic_bug_12435_10, !config_.negotiated())
<< ENDPOINT << "Handshake completes without parameter negotiation.";
connection()->mutable_stats().handshake_completion_time =
connection()->clock()->ApproximateNow();
if (connection()->version().UsesTls() &&
perspective_ == Perspective::IS_SERVER) {
// Server sends HANDSHAKE_DONE to signal confirmation of the handshake
// to the client.
control_frame_manager_.WriteOrBufferHandshakeDone();
if (connection()->version().HasIetfQuicFrames()) {
MaybeSendAddressToken();
}
}
}
bool QuicSession::MaybeSendAddressToken() {
QUICHE_DCHECK(perspective_ == Perspective::IS_SERVER &&
connection()->version().HasIetfQuicFrames());
absl::optional<CachedNetworkParameters> cached_network_params;
if (add_cached_network_parameters_to_address_token()) {
cached_network_params = GenerateCachedNetworkParameters();
}
std::string address_token = GetCryptoStream()->GetAddressToken(
cached_network_params.has_value() ? &cached_network_params.value()
: nullptr);
if (address_token.empty()) {
return false;
}
const size_t buf_len = address_token.length() + 1;
auto buffer = std::make_unique<char[]>(buf_len);
QuicDataWriter writer(buf_len, buffer.get());
// Add prefix 0 for token sent in NEW_TOKEN frame.
writer.WriteUInt8(0);
writer.WriteBytes(address_token.data(), address_token.length());
control_frame_manager_.WriteOrBufferNewToken(
absl::string_view(buffer.get(), buf_len));
if (add_cached_network_parameters_to_address_token() &&
cached_network_params.has_value()) {
connection()->OnSendConnectionState(*cached_network_params);
QUIC_RELOADABLE_FLAG_COUNT_N(
quic_add_cached_network_parameters_to_address_token2, 1, 2);
}
return true;
}
void QuicSession::DiscardOldDecryptionKey(EncryptionLevel level) {
if (!connection()->version().KnowsWhichDecrypterToUse()) {
return;
}
connection()->RemoveDecrypter(level);
}
void QuicSession::DiscardOldEncryptionKey(EncryptionLevel level) {
QUIC_DLOG(INFO) << ENDPOINT << "Discarding " << level << " keys";
if (connection()->version().handshake_protocol == PROTOCOL_TLS1_3) {
connection()->RemoveEncrypter(level);
}
switch (level) {
case ENCRYPTION_INITIAL:
NeuterUnencryptedData();
break;
case ENCRYPTION_HANDSHAKE:
NeuterHandshakeData();
break;
case ENCRYPTION_ZERO_RTT:
break;
case ENCRYPTION_FORWARD_SECURE:
QUIC_BUG(quic_bug_10866_8)
<< ENDPOINT << "Discarding 1-RTT keys is not allowed";
break;
default:
QUIC_BUG(quic_bug_10866_9)
<< ENDPOINT
<< "Cannot discard keys for unknown encryption level: " << level;
}
}
void QuicSession::NeuterHandshakeData() {
GetMutableCryptoStream()->NeuterStreamDataOfEncryptionLevel(
ENCRYPTION_HANDSHAKE);
connection()->OnHandshakeComplete();
}
void QuicSession::OnZeroRttRejected(int reason) {
was_zero_rtt_rejected_ = true;
connection_->MarkZeroRttPacketsForRetransmission(reason);
if (connection_->encryption_level() == ENCRYPTION_FORWARD_SECURE) {
QUIC_BUG(quic_bug_10866_10)
<< "1-RTT keys already available when 0-RTT is rejected.";
connection_->CloseConnection(
QUIC_INTERNAL_ERROR,
"1-RTT keys already available when 0-RTT is rejected.",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
}
}
bool QuicSession::FillTransportParameters(TransportParameters* params) {
if (version().UsesTls()) {
if (perspective() == Perspective::IS_SERVER) {
config_.SetOriginalConnectionIdToSend(
connection_->GetOriginalDestinationConnectionId());
config_.SetInitialSourceConnectionIdToSend(connection_->connection_id());
} else {
config_.SetInitialSourceConnectionIdToSend(
connection_->client_connection_id());
}
}
return config_.FillTransportParameters(params);
}
QuicErrorCode QuicSession::ProcessTransportParameters(
const TransportParameters& params, bool is_resumption,
std::string* error_details) {
return config_.ProcessTransportParameters(params, is_resumption,
error_details);
}
void QuicSession::OnHandshakeCallbackDone() {
if (!connection_->connected()) {
return;
}
if (!connection()->is_processing_packet()) {
connection()->MaybeProcessUndecryptablePackets();
}
}
bool QuicSession::PacketFlusherAttached() const {
QUICHE_DCHECK(connection_->connected());
return connection()->packet_creator().PacketFlusherAttached();
}
void QuicSession::OnCryptoHandshakeMessageSent(
const CryptoHandshakeMessage& /*message*/) {}
void QuicSession::OnCryptoHandshakeMessageReceived(
const CryptoHandshakeMessage& /*message*/) {}
void QuicSession::RegisterStreamPriority(
QuicStreamId id, bool is_static,
const spdy::SpdyStreamPrecedence& precedence) {
write_blocked_streams()->RegisterStream(id, is_static, precedence);
}
void QuicSession::UnregisterStreamPriority(QuicStreamId id, bool is_static) {
write_blocked_streams()->UnregisterStream(id, is_static);
}
void QuicSession::UpdateStreamPriority(
QuicStreamId id, const spdy::SpdyStreamPrecedence& new_precedence) {
write_blocked_streams()->UpdateStreamPriority(id, new_precedence);
}
QuicConfig* QuicSession::config() { return &config_; }
void QuicSession::ActivateStream(std::unique_ptr<QuicStream> stream) {
QuicStreamId stream_id = stream->id();
bool is_static = stream->is_static();
QUIC_DVLOG(1) << ENDPOINT << "num_streams: " << stream_map_.size()
<< ". activating stream " << stream_id;
QUICHE_DCHECK(!stream_map_.contains(stream_id));
stream_map_[stream_id] = std::move(stream);
if (is_static) {
++num_static_streams_;
return;
}
if (!VersionHasIetfQuicFrames(transport_version())) {
// Do not inform stream ID manager of static streams.
stream_id_manager_.ActivateStream(
/*is_incoming=*/IsIncomingStream(stream_id));
}
}
QuicStreamId QuicSession::GetNextOutgoingBidirectionalStreamId() {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetNextOutgoingBidirectionalStreamId();
}
return stream_id_manager_.GetNextOutgoingStreamId();
}
QuicStreamId QuicSession::GetNextOutgoingUnidirectionalStreamId() {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetNextOutgoingUnidirectionalStreamId();
}
return stream_id_manager_.GetNextOutgoingStreamId();
}
bool QuicSession::CanOpenNextOutgoingBidirectionalStream() {
if (liveness_testing_in_progress_) {
QUICHE_DCHECK_EQ(Perspective::IS_CLIENT, perspective());
return false;
}
if (!VersionHasIetfQuicFrames(transport_version())) {
if (!stream_id_manager_.CanOpenNextOutgoingStream()) {
return false;
}
} else {
if (!ietf_streamid_manager_.CanOpenNextOutgoingBidirectionalStream()) {
if (is_configured_) {
// Send STREAM_BLOCKED after config negotiated.
control_frame_manager_.WriteOrBufferStreamsBlocked(
ietf_streamid_manager_.max_outgoing_bidirectional_streams(),
/*unidirectional=*/false);
}
return false;
}
}
if (perspective() == Perspective::IS_CLIENT &&
connection_->MaybeTestLiveness()) {
// Now is relatively close to the idle timeout having the risk that requests
// could be discarded at the server.
liveness_testing_in_progress_ = true;
return false;
}
return true;
}
bool QuicSession::CanOpenNextOutgoingUnidirectionalStream() {
if (!VersionHasIetfQuicFrames(transport_version())) {
return stream_id_manager_.CanOpenNextOutgoingStream();
}
if (ietf_streamid_manager_.CanOpenNextOutgoingUnidirectionalStream()) {
return true;
}
if (is_configured_) {
// Send STREAM_BLOCKED after config negotiated.
control_frame_manager_.WriteOrBufferStreamsBlocked(
ietf_streamid_manager_.max_outgoing_unidirectional_streams(),
/*unidirectional=*/true);
}
return false;
}
QuicStreamCount QuicSession::GetAdvertisedMaxIncomingBidirectionalStreams()
const {
QUICHE_DCHECK(VersionHasIetfQuicFrames(transport_version()));
return ietf_streamid_manager_.advertised_max_incoming_bidirectional_streams();
}
QuicStream* QuicSession::GetOrCreateStream(const QuicStreamId stream_id) {
QUICHE_DCHECK(!pending_stream_map_.contains(stream_id));
if (QuicUtils::IsCryptoStreamId(transport_version(), stream_id)) {
return GetMutableCryptoStream();
}
StreamMap::iterator it = stream_map_.find(stream_id);
if (it != stream_map_.end()) {
return it->second->IsZombie() ? nullptr : it->second.get();
}
if (IsClosedStream(stream_id)) {
return nullptr;
}
if (!IsIncomingStream(stream_id)) {
HandleFrameOnNonexistentOutgoingStream(stream_id);
return nullptr;
}
// TODO(fkastenholz): If we are creating a new stream and we have sent a
// goaway, we should ignore the stream creation. Need to add code to A) test
// if goaway was sent ("if (transport_goaway_sent_)") and B) reject stream
// creation ("return nullptr")
if (!MaybeIncreaseLargestPeerStreamId(stream_id)) {
return nullptr;
}
if (!VersionHasIetfQuicFrames(transport_version()) &&
!stream_id_manager_.CanOpenIncomingStream()) {
// Refuse to open the stream.
ResetStream(stream_id, QUIC_REFUSED_STREAM);
return nullptr;
}
return CreateIncomingStream(stream_id);
}
void QuicSession::StreamDraining(QuicStreamId stream_id, bool unidirectional) {
QUICHE_DCHECK(stream_map_.contains(stream_id));
QUIC_DVLOG(1) << ENDPOINT << "Stream " << stream_id << " is draining";
if (VersionHasIetfQuicFrames(transport_version())) {
ietf_streamid_manager_.OnStreamClosed(stream_id);
} else {
stream_id_manager_.OnStreamClosed(
/*is_incoming=*/IsIncomingStream(stream_id));
}
++num_draining_streams_;
if (!IsIncomingStream(stream_id)) {
++num_outgoing_draining_streams_;
if (!VersionHasIetfQuicFrames(transport_version())) {
OnCanCreateNewOutgoingStream(unidirectional);
}
}
}
bool QuicSession::MaybeIncreaseLargestPeerStreamId(
const QuicStreamId stream_id) {
if (VersionHasIetfQuicFrames(transport_version())) {
std::string error_details;
if (ietf_streamid_manager_.MaybeIncreaseLargestPeerStreamId(
stream_id, &error_details)) {
return true;
}
connection()->CloseConnection(
QUIC_INVALID_STREAM_ID, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
if (!stream_id_manager_.MaybeIncreaseLargestPeerStreamId(stream_id)) {
connection()->CloseConnection(
QUIC_TOO_MANY_AVAILABLE_STREAMS,
absl::StrCat(stream_id, " exceeds available streams ",
stream_id_manager_.MaxAvailableStreams()),
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
return true;
}
bool QuicSession::ShouldYield(QuicStreamId stream_id) {
if (stream_id == currently_writing_stream_id_) {
return false;
}
return write_blocked_streams()->ShouldYield(stream_id);
}
PendingStream* QuicSession::GetOrCreatePendingStream(QuicStreamId stream_id) {
auto it = pending_stream_map_.find(stream_id);
if (it != pending_stream_map_.end()) {
return it->second.get();
}
if (IsClosedStream(stream_id) ||
!MaybeIncreaseLargestPeerStreamId(stream_id)) {
return nullptr;
}
auto pending = std::make_unique<PendingStream>(stream_id, this);
PendingStream* unowned_pending = pending.get();
pending_stream_map_[stream_id] = std::move(pending);
return unowned_pending;
}
void QuicSession::set_largest_peer_created_stream_id(
QuicStreamId largest_peer_created_stream_id) {
QUICHE_DCHECK(!VersionHasIetfQuicFrames(transport_version()));
stream_id_manager_.set_largest_peer_created_stream_id(
largest_peer_created_stream_id);
}
QuicStreamId QuicSession::GetLargestPeerCreatedStreamId(
bool unidirectional) const {
// This method is only used in IETF QUIC.
QUICHE_DCHECK(VersionHasIetfQuicFrames(transport_version()));
return ietf_streamid_manager_.GetLargestPeerCreatedStreamId(unidirectional);
}
void QuicSession::DeleteConnection() {
if (connection_) {
delete connection_;
connection_ = nullptr;
}
}
bool QuicSession::MaybeSetStreamPriority(
QuicStreamId stream_id, const spdy::SpdyStreamPrecedence& precedence) {
auto active_stream = stream_map_.find(stream_id);
if (active_stream != stream_map_.end()) {
active_stream->second->SetPriority(precedence);
return true;
}
return false;
}
bool QuicSession::IsClosedStream(QuicStreamId id) {
QUICHE_DCHECK_NE(QuicUtils::GetInvalidStreamId(transport_version()), id);
if (IsOpenStream(id)) {
// Stream is active
return false;
}
if (VersionHasIetfQuicFrames(transport_version())) {
return !ietf_streamid_manager_.IsAvailableStream(id);
}
return !stream_id_manager_.IsAvailableStream(id);
}
bool QuicSession::IsOpenStream(QuicStreamId id) {
QUICHE_DCHECK_NE(QuicUtils::GetInvalidStreamId(transport_version()), id);
const StreamMap::iterator it = stream_map_.find(id);
if (it != stream_map_.end()) {
return !it->second->IsZombie();
}
if (pending_stream_map_.contains(id) ||
QuicUtils::IsCryptoStreamId(transport_version(), id)) {
// Stream is active
return true;
}
return false;
}
bool QuicSession::IsStaticStream(QuicStreamId id) const {
auto it = stream_map_.find(id);
if (it == stream_map_.end()) {
return false;
}
return it->second->is_static();
}
size_t QuicSession::GetNumActiveStreams() const {
QUICHE_DCHECK_GE(
static_cast<QuicStreamCount>(stream_map_.size()),
num_static_streams_ + num_draining_streams_ + num_zombie_streams_);
return stream_map_.size() - num_draining_streams_ - num_static_streams_ -
num_zombie_streams_;
}
void QuicSession::MarkConnectionLevelWriteBlocked(QuicStreamId id) {
if (GetOrCreateStream(id) == nullptr) {
QUIC_BUG(quic_bug_10866_11)
<< "Marking unknown stream " << id << " blocked.";
QUIC_LOG_FIRST_N(ERROR, 2) << QuicStackTrace();
}
QUIC_DVLOG(1) << ENDPOINT << "Adding stream " << id
<< " to write-blocked list";
write_blocked_streams_.AddStream(id);
}
bool QuicSession::HasDataToWrite() const {
return write_blocked_streams_.HasWriteBlockedSpecialStream() ||
write_blocked_streams_.HasWriteBlockedDataStreams() ||
connection_->HasQueuedData() ||
!streams_with_pending_retransmission_.empty() ||
control_frame_manager_.WillingToWrite();
}
void QuicSession::OnAckNeedsRetransmittableFrame() {
flow_controller_.SendWindowUpdate();
}
void QuicSession::SendAckFrequency(const QuicAckFrequencyFrame& frame) {
control_frame_manager_.WriteOrBufferAckFrequency(frame);
}
void QuicSession::SendNewConnectionId(const QuicNewConnectionIdFrame& frame) {
// Count NEW_CONNECTION_ID frames sent to client.
QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 1, 6);
control_frame_manager_.WriteOrBufferNewConnectionId(
frame.connection_id, frame.sequence_number, frame.retire_prior_to,
frame.stateless_reset_token);
}
void QuicSession::SendRetireConnectionId(uint64_t sequence_number) {
// Count RETIRE_CONNECTION_ID frames sent to client.
QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 2, 6);
control_frame_manager_.WriteOrBufferRetireConnectionId(sequence_number);
}
void QuicSession::OnServerConnectionIdIssued(
const QuicConnectionId& server_connection_id) {
if (visitor_) {
visitor_->OnNewConnectionIdSent(
connection_->GetOneActiveServerConnectionId(), server_connection_id);
}
}
void QuicSession::OnServerConnectionIdRetired(
const QuicConnectionId& server_connection_id) {
if (visitor_) {
visitor_->OnConnectionIdRetired(server_connection_id);
}
}
bool QuicSession::IsConnectionFlowControlBlocked() const {
return flow_controller_.IsBlocked();
}
bool QuicSession::IsStreamFlowControlBlocked() {
for (auto const& kv : stream_map_) {
if (kv.second->IsFlowControlBlocked()) {
return true;
}
}
if (!QuicVersionUsesCryptoFrames(transport_version()) &&
GetMutableCryptoStream()->IsFlowControlBlocked()) {
return true;
}
return false;
}
size_t QuicSession::MaxAvailableBidirectionalStreams() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetMaxAllowdIncomingBidirectionalStreams();
}
return stream_id_manager_.MaxAvailableStreams();
}
size_t QuicSession::MaxAvailableUnidirectionalStreams() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetMaxAllowdIncomingUnidirectionalStreams();
}
return stream_id_manager_.MaxAvailableStreams();
}
bool QuicSession::IsIncomingStream(QuicStreamId id) const {
if (VersionHasIetfQuicFrames(transport_version())) {
return !QuicUtils::IsOutgoingStreamId(version(), id, perspective_);
}
return stream_id_manager_.IsIncomingStream(id);
}
void QuicSession::MaybeCloseZombieStream(QuicStreamId id) {
auto it = stream_map_.find(id);
if (it == stream_map_.end()) {
return;
}
--num_zombie_streams_;
closed_streams_.push_back(std::move(it->second));
stream_map_.erase(it);
if (!closed_streams_clean_up_alarm_->IsSet()) {
closed_streams_clean_up_alarm_->Set(connection_->clock()->ApproximateNow());
}
// Do not retransmit data of a closed stream.
streams_with_pending_retransmission_.erase(id);
QUIC_BUG_IF(364846171_2,
connection_->packet_creator().HasPendingStreamFramesOfStream(id))
<< "Stream " << id << " gets closed while there are pending frames.";
}
QuicStream* QuicSession::GetStream(QuicStreamId id) const {
auto active_stream = stream_map_.find(id);
if (active_stream != stream_map_.end()) {
return active_stream->second.get();
}
if (QuicUtils::IsCryptoStreamId(transport_version(), id)) {
return const_cast<QuicCryptoStream*>(GetCryptoStream());
}
return nullptr;
}
QuicStream* QuicSession::GetActiveStream(QuicStreamId id) const {
auto stream = stream_map_.find(id);
if (stream != stream_map_.end() && !stream->second->is_static()) {
return stream->second.get();
}
return nullptr;
}
bool QuicSession::OnFrameAcked(const QuicFrame& frame,
QuicTime::Delta ack_delay_time,
QuicTime receive_timestamp) {
if (frame.type == MESSAGE_FRAME) {
OnMessageAcked(frame.message_frame->message_id, receive_timestamp);
return true;
}
if (frame.type == CRYPTO_FRAME) {
return GetMutableCryptoStream()->OnCryptoFrameAcked(*frame.crypto_frame,
ack_delay_time);
}
if (frame.type != STREAM_FRAME) {
return control_frame_manager_.OnControlFrameAcked(frame);
}
bool new_stream_data_acked = false;
QuicStream* stream = GetStream(frame.stream_frame.stream_id);
// Stream can already be reset when sent frame gets acked.
if (stream != nullptr) {
QuicByteCount newly_acked_length = 0;
new_stream_data_acked = stream->OnStreamFrameAcked(
frame.stream_frame.offset, frame.stream_frame.data_length,
frame.stream_frame.fin, ack_delay_time, receive_timestamp,
&newly_acked_length);
if (!stream->HasPendingRetransmission()) {
streams_with_pending_retransmission_.erase(stream->id());
}
}
return new_stream_data_acked;
}
void QuicSession::OnStreamFrameRetransmitted(const QuicStreamFrame& frame) {
QuicStream* stream = GetStream(frame.stream_id);
if (stream == nullptr) {
QUIC_BUG(quic_bug_10866_12)
<< "Stream: " << frame.stream_id << " is closed when " << frame
<< " is retransmitted.";
connection()->CloseConnection(
QUIC_INTERNAL_ERROR, "Attempt to retransmit frame of a closed stream",
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return;
}
stream->OnStreamFrameRetransmitted(frame.offset, frame.data_length,
frame.fin);
}
void QuicSession::OnFrameLost(const QuicFrame& frame) {
if (frame.type == MESSAGE_FRAME) {
OnMessageLost(frame.message_frame->message_id);
return;
}
if (frame.type == CRYPTO_FRAME) {
GetMutableCryptoStream()->OnCryptoFrameLost(frame.crypto_frame);
return;
}
if (frame.type != STREAM_FRAME) {
control_frame_manager_.OnControlFrameLost(frame);
return;
}
QuicStream* stream = GetStream(frame.stream_frame.stream_id);
if (stream == nullptr) {
return;
}
stream->OnStreamFrameLost(frame.stream_frame.offset,
frame.stream_frame.data_length,
frame.stream_frame.fin);
if (stream->HasPendingRetransmission() &&
!streams_with_pending_retransmission_.contains(
frame.stream_frame.stream_id)) {
streams_with_pending_retransmission_.insert(
std::make_pair(frame.stream_frame.stream_id, true));
}
}
void QuicSession::RetransmitFrames(const QuicFrames& frames,
TransmissionType type) {
QuicConnection::ScopedPacketFlusher retransmission_flusher(connection_);
for (const QuicFrame& frame : frames) {
if (frame.type == MESSAGE_FRAME) {
// Do not retransmit MESSAGE frames.
continue;
}
if (frame.type == CRYPTO_FRAME) {
GetMutableCryptoStream()->RetransmitData(frame.crypto_frame, type);
continue;
}
if (frame.type != STREAM_FRAME) {
if (!control_frame_manager_.RetransmitControlFrame(frame, type)) {
break;
}
continue;
}
QuicStream* stream = GetStream(frame.stream_frame.stream_id);
if (stream != nullptr &&
!stream->RetransmitStreamData(frame.stream_frame.offset,
frame.stream_frame.data_length,
frame.stream_frame.fin, type)) {
break;
}
}
}
bool QuicSession::IsFrameOutstanding(const QuicFrame& frame) const {
if (frame.type == MESSAGE_FRAME) {
return false;
}
if (frame.type == CRYPTO_FRAME) {
return GetCryptoStream()->IsFrameOutstanding(
frame.crypto_frame->level, frame.crypto_frame->offset,
frame.crypto_frame->data_length);
}
if (frame.type != STREAM_FRAME) {
return control_frame_manager_.IsControlFrameOutstanding(frame);
}
QuicStream* stream = GetStream(frame.stream_frame.stream_id);
return stream != nullptr &&
stream->IsStreamFrameOutstanding(frame.stream_frame.offset,
frame.stream_frame.data_length,
frame.stream_frame.fin);
}
bool QuicSession::HasUnackedCryptoData() const {
const QuicCryptoStream* crypto_stream = GetCryptoStream();
return crypto_stream->IsWaitingForAcks() || crypto_stream->HasBufferedData();
}
bool QuicSession::HasUnackedStreamData() const {
for (const auto& it : stream_map_) {
if (it.second->IsWaitingForAcks()) {
return true;
}
}
return false;
}
HandshakeState QuicSession::GetHandshakeState() const {
return GetCryptoStream()->GetHandshakeState();
}
WriteStreamDataResult QuicSession::WriteStreamData(QuicStreamId id,
QuicStreamOffset offset,
QuicByteCount data_length,
QuicDataWriter* writer) {
QuicStream* stream = GetStream(id);
if (stream == nullptr) {
// This causes the connection to be closed because of failed to serialize
// packet.
QUIC_BUG(quic_bug_10866_13)
<< "Stream " << id << " does not exist when trying to write data."
<< " version:" << transport_version();
return STREAM_MISSING;
}
if (stream->WriteStreamData(offset, data_length, writer)) {
return WRITE_SUCCESS;
}
return WRITE_FAILED;
}
bool QuicSession::WriteCryptoData(EncryptionLevel level,
QuicStreamOffset offset,
QuicByteCount data_length,
QuicDataWriter* writer) {
return GetMutableCryptoStream()->WriteCryptoFrame(level, offset, data_length,
writer);
}
StatelessResetToken QuicSession::GetStatelessResetToken() const {
return QuicUtils::GenerateStatelessResetToken(connection_->connection_id());
}
bool QuicSession::CanWriteStreamData() const {
// Don't write stream data if there are queued data packets.
if (connection_->HasQueuedPackets()) {
return false;
}
// Immediately write handshake data.
if (HasPendingHandshake()) {
return true;
}
return connection_->CanWrite(HAS_RETRANSMITTABLE_DATA);
}
bool QuicSession::RetransmitLostData() {
QuicConnection::ScopedPacketFlusher retransmission_flusher(connection_);
// Retransmit crypto data first.
bool uses_crypto_frames = QuicVersionUsesCryptoFrames(transport_version());
QuicCryptoStream* crypto_stream = GetMutableCryptoStream();
if (uses_crypto_frames && crypto_stream->HasPendingCryptoRetransmission()) {
crypto_stream->WritePendingCryptoRetransmission();
}
// Retransmit crypto data in stream 1 frames (version < 47).
if (!uses_crypto_frames &&
streams_with_pending_retransmission_.contains(
QuicUtils::GetCryptoStreamId(transport_version()))) {
// Retransmit crypto data first.
QuicStream* crypto_stream =
GetStream(QuicUtils::GetCryptoStreamId(transport_version()));
crypto_stream->OnCanWrite();
QUICHE_DCHECK(CheckStreamWriteBlocked(crypto_stream));
if (crypto_stream->HasPendingRetransmission()) {
// Connection is write blocked.
return false;
} else {
streams_with_pending_retransmission_.erase(
QuicUtils::GetCryptoStreamId(transport_version()));
}
}
if (control_frame_manager_.HasPendingRetransmission()) {
control_frame_manager_.OnCanWrite();
if (control_frame_manager_.HasPendingRetransmission()) {
return false;
}
}
while (!streams_with_pending_retransmission_.empty()) {
if (!CanWriteStreamData()) {
break;
}
// Retransmit lost data on headers and data streams.
const QuicStreamId id = streams_with_pending_retransmission_.begin()->first;
QuicStream* stream = GetStream(id);
if (stream != nullptr) {
stream->OnCanWrite();
QUICHE_DCHECK(CheckStreamWriteBlocked(stream));
if (stream->HasPendingRetransmission()) {
// Connection is write blocked.
break;
} else if (!streams_with_pending_retransmission_.empty() &&
streams_with_pending_retransmission_.begin()->first == id) {
// Retransmit lost data may cause connection close. If this stream
// has not yet sent fin, a RST_STREAM will be sent and it will be
// removed from streams_with_pending_retransmission_.
streams_with_pending_retransmission_.pop_front();
}
} else {
QUIC_BUG(quic_bug_10866_14)
<< "Try to retransmit data of a closed stream";
streams_with_pending_retransmission_.pop_front();
}
}
return streams_with_pending_retransmission_.empty();
}
void QuicSession::NeuterUnencryptedData() {
QuicCryptoStream* crypto_stream = GetMutableCryptoStream();
crypto_stream->NeuterUnencryptedStreamData();
if (!crypto_stream->HasPendingRetransmission() &&
!QuicVersionUsesCryptoFrames(transport_version())) {
streams_with_pending_retransmission_.erase(
QuicUtils::GetCryptoStreamId(transport_version()));
}
connection_->NeuterUnencryptedPackets();
}
void QuicSession::SetTransmissionType(TransmissionType type) {
connection_->SetTransmissionType(type);
}
MessageResult QuicSession::SendMessage(absl::Span<QuicMemSlice> message) {
return SendMessage(message, /*flush=*/false);
}
MessageResult QuicSession::SendMessage(QuicMemSlice message) {
return SendMessage(absl::MakeSpan(&message, 1), /*flush=*/false);
}
MessageResult QuicSession::SendMessage(absl::Span<QuicMemSlice> message,
bool flush) {
QUICHE_DCHECK(connection_->connected())
<< ENDPOINT << "Try to write messages when connection is closed.";
if (!IsEncryptionEstablished()) {
return {MESSAGE_STATUS_ENCRYPTION_NOT_ESTABLISHED, 0};
}
QuicConnection::ScopedEncryptionLevelContext context(
connection(), GetEncryptionLevelToSendApplicationData());
MessageStatus result =
connection_->SendMessage(last_message_id_ + 1, message, flush);
if (result == MESSAGE_STATUS_SUCCESS) {
return {result, ++last_message_id_};
}
return {result, 0};
}
void QuicSession::OnMessageAcked(QuicMessageId message_id,
QuicTime /*receive_timestamp*/) {
QUIC_DVLOG(1) << ENDPOINT << "message " << message_id << " gets acked.";
}
void QuicSession::OnMessageLost(QuicMessageId message_id) {
QUIC_DVLOG(1) << ENDPOINT << "message " << message_id
<< " is considered lost";
}
void QuicSession::CleanUpClosedStreams() { closed_streams_.clear(); }
QuicPacketLength QuicSession::GetCurrentLargestMessagePayload() const {
return connection_->GetCurrentLargestMessagePayload();
}
QuicPacketLength QuicSession::GetGuaranteedLargestMessagePayload() const {
return connection_->GetGuaranteedLargestMessagePayload();
}
QuicStreamId QuicSession::next_outgoing_bidirectional_stream_id() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.next_outgoing_bidirectional_stream_id();
}
return stream_id_manager_.next_outgoing_stream_id();
}
QuicStreamId QuicSession::next_outgoing_unidirectional_stream_id() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.next_outgoing_unidirectional_stream_id();
}
return stream_id_manager_.next_outgoing_stream_id();
}
bool QuicSession::OnMaxStreamsFrame(const QuicMaxStreamsFrame& frame) {
const bool allow_new_streams =
frame.unidirectional
? ietf_streamid_manager_.MaybeAllowNewOutgoingUnidirectionalStreams(
frame.stream_count)
: ietf_streamid_manager_.MaybeAllowNewOutgoingBidirectionalStreams(
frame.stream_count);
if (allow_new_streams) {
OnCanCreateNewOutgoingStream(frame.unidirectional);
}
return true;
}
bool QuicSession::OnStreamsBlockedFrame(const QuicStreamsBlockedFrame& frame) {
std::string error_details;
if (ietf_streamid_manager_.OnStreamsBlockedFrame(frame, &error_details)) {
return true;
}
connection_->CloseConnection(
QUIC_STREAMS_BLOCKED_ERROR, error_details,
ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
return false;
}
size_t QuicSession::max_open_incoming_bidirectional_streams() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetMaxAllowdIncomingBidirectionalStreams();
}
return stream_id_manager_.max_open_incoming_streams();
}
size_t QuicSession::max_open_incoming_unidirectional_streams() const {
if (VersionHasIetfQuicFrames(transport_version())) {
return ietf_streamid_manager_.GetMaxAllowdIncomingUnidirectionalStreams();
}
return stream_id_manager_.max_open_incoming_streams();
}
std::vector<absl::string_view>::const_iterator QuicSession::SelectAlpn(
const std::vector<absl::string_view>& alpns) const {
const std::string alpn = AlpnForVersion(connection()->version());
return std::find(alpns.cbegin(), alpns.cend(), alpn);
}
void QuicSession::OnAlpnSelected(absl::string_view alpn) {
QUIC_DLOG(INFO) << (perspective() == Perspective::IS_SERVER ? "Server: "
: "Client: ")
<< "ALPN selected: " << alpn;
}
void QuicSession::NeuterCryptoDataOfEncryptionLevel(EncryptionLevel level) {
GetMutableCryptoStream()->NeuterStreamDataOfEncryptionLevel(level);
}
void QuicSession::PerformActionOnActiveStreams(
std::function<bool(QuicStream*)> action) {
std::vector<QuicStream*> active_streams;
for (const auto& it : stream_map_) {
if (!it.second->is_static() && !it.second->IsZombie()) {
active_streams.push_back(it.second.get());
}
}
for (QuicStream* stream : active_streams) {
if (!action(stream)) {
return;
}
}
}
void QuicSession::PerformActionOnActiveStreams(
std::function<bool(QuicStream*)> action) const {
for (const auto& it : stream_map_) {
if (!it.second->is_static() && !it.second->IsZombie