net/quic/reliable_quic_stream.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/quic/reliable_quic_stream.h"
   6
   7 #include "base/logging.h"
   8 #include "net/quic/iovector.h"
   9 #include "net/quic/quic_flow_controller.h"
  10 #include "net/quic/quic_session.h"
  11 #include "net/quic/quic_write_blocked_list.h"
  12
  13 using base::StringPiece;
  14 using std::min;
  15 using std::string;
  16
  17 namespace net {
  18
  19 #define ENDPOINT \
  20   (perspective_ == Perspective::IS_SERVER ? "Server: " : "Client: ")
  21
  22 namespace {
  23
  24 struct iovec MakeIovec(StringPiece data) {
  25   struct iovec iov = {const_cast<char*>(data.data()),
  26                       static_cast<size_t>(data.size())};
  27   return iov;
  28 }
  29
  30 size_t GetInitialStreamFlowControlWindowToSend(QuicSession* session) {
  31   return session->config()->GetInitialStreamFlowControlWindowToSend();
  32 }
  33
  34 size_t GetReceivedFlowControlWindow(QuicSession* session) {
  35   if (session->config()->HasReceivedInitialStreamFlowControlWindowBytes()) {
  36     return session->config()->ReceivedInitialStreamFlowControlWindowBytes();
  37   }
  38
  39   return kMinimumFlowControlSendWindow;
  40 }
  41
  42 }  // namespace
  43
  44 // Wrapper that aggregates OnAckNotifications for packets sent using
  45 // WriteOrBufferData and delivers them to the original
  46 // QuicAckNotifier::DelegateInterface after all bytes written using
  47 // WriteOrBufferData are acked.  This level of indirection is
  48 // necessary because the delegate interface provides no mechanism that
  49 // WriteOrBufferData can use to inform it that the write required
  50 // multiple WritevData calls or that only part of the data has been
  51 // sent out by the time ACKs start arriving.
  52 class ReliableQuicStream::ProxyAckNotifierDelegate
  53     : public QuicAckNotifier::DelegateInterface {
  54  public:
  55   explicit ProxyAckNotifierDelegate(DelegateInterface* delegate)
  56       : delegate_(delegate),
  57         pending_acks_(0),
  58         wrote_last_data_(false),
  59         num_retransmitted_packets_(0),
  60         num_retransmitted_bytes_(0) {
  61   }
  62
  63   void OnAckNotification(int num_retransmitted_packets,
  64                          int num_retransmitted_bytes,
  65                          QuicTime::Delta delta_largest_observed) override {
  66     DCHECK_LT(0, pending_acks_);
  67     --pending_acks_;
  68     num_retransmitted_packets_ += num_retransmitted_packets;
  69     num_retransmitted_bytes_ += num_retransmitted_bytes;
  70
  71     if (wrote_last_data_ && pending_acks_ == 0) {
  72       delegate_->OnAckNotification(num_retransmitted_packets_,
  73                                    num_retransmitted_bytes_,
  74                                    delta_largest_observed);
  75     }
  76   }
  77
  78   void WroteData(bool last_data) {
  79     DCHECK(!wrote_last_data_);
  80     ++pending_acks_;
  81     wrote_last_data_ = last_data;
  82   }
  83
  84  protected:
  85   // Delegates are ref counted.
  86   ~ProxyAckNotifierDelegate() override {}
  87
  88  private:
  89   // Original delegate.  delegate_->OnAckNotification will be called when:
  90   //   wrote_last_data_ == true and pending_acks_ == 0
  91   scoped_refptr<DelegateInterface> delegate_;
  92
  93   // Number of outstanding acks.
  94   int pending_acks_;
  95
  96   // True if no pending writes remain.
  97   bool wrote_last_data_;
  98
  99   int num_retransmitted_packets_;
 100   int num_retransmitted_bytes_;
 101
 102   DISALLOW_COPY_AND_ASSIGN(ProxyAckNotifierDelegate);
 103 };
 104
 105 ReliableQuicStream::PendingData::PendingData(
 106     string data_in, scoped_refptr<ProxyAckNotifierDelegate> delegate_in)
 107     : data(data_in), delegate(delegate_in) {
 108 }
 109
 110 ReliableQuicStream::PendingData::~PendingData() {
 111 }
 112
 113 ReliableQuicStream::ReliableQuicStream(QuicStreamId id, QuicSession* session)
 114     : sequencer_(this),
 115       id_(id),
 116       session_(session),
 117       stream_bytes_read_(0),
 118       stream_bytes_written_(0),
 119       stream_error_(QUIC_STREAM_NO_ERROR),
 120       connection_error_(QUIC_NO_ERROR),
 121       read_side_closed_(false),
 122       write_side_closed_(false),
 123       fin_buffered_(false),
 124       fin_sent_(false),
 125       fin_received_(false),
 126       rst_sent_(false),
 127       rst_received_(false),
 128       fec_policy_(FEC_PROTECT_OPTIONAL),
 129       perspective_(session_->perspective()),
 130       flow_controller_(session_->connection(),
 131                        id_,
 132                        perspective_,
 133                        GetReceivedFlowControlWindow(session),
 134                        GetInitialStreamFlowControlWindowToSend(session),
 135                        GetInitialStreamFlowControlWindowToSend(session)),
 136       connection_flow_controller_(session_->flow_controller()),
 137       stream_contributes_to_connection_flow_control_(true) {
 138 }
 139
 140 ReliableQuicStream::~ReliableQuicStream() {
 141 }
 142
 143 void ReliableQuicStream::OnStreamFrame(const QuicStreamFrame& frame) {
 144   if (read_side_closed_) {
 145     DVLOG(1) << ENDPOINT << "Ignoring frame " << frame.stream_id;
 146     // We don't want to be reading: blackhole the data.
 147     return;
 148   }
 149
 150   if (frame.stream_id != id_) {
 151     session_->connection()->SendConnectionClose(QUIC_INTERNAL_ERROR);
 152     return;
 153   }
 154
 155   if (frame.fin) {
 156     fin_received_ = true;
 157   }
 158
 159   // This count include duplicate data received.
 160   size_t frame_payload_size = frame.data.TotalBufferSize();
 161   stream_bytes_read_ += frame_payload_size;
 162
 163   // Flow control is interested in tracking highest received offset.
 164   if (MaybeIncreaseHighestReceivedOffset(frame.offset + frame_payload_size)) {
 165     // As the highest received offset has changed, we should check to see if
 166     // this is a violation of flow control.
 167     if (flow_controller_.FlowControlViolation() ||
 168         connection_flow_controller_->FlowControlViolation()) {
 169       session_->connection()->SendConnectionClose(
 170           QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA);
 171       return;
 172     }
 173   }
 174
 175   sequencer_.OnStreamFrame(frame);
 176 }
 177
 178 int ReliableQuicStream::num_frames_received() const {
 179   return sequencer_.num_frames_received();
 180 }
 181
 182 int ReliableQuicStream::num_early_frames_received() const {
 183   return sequencer_.num_early_frames_received();
 184 }
 185
 186 int ReliableQuicStream::num_duplicate_frames_received() const {
 187   return sequencer_.num_duplicate_frames_received();
 188 }
 189
 190 void ReliableQuicStream::OnStreamReset(const QuicRstStreamFrame& frame) {
 191   rst_received_ = true;
 192   MaybeIncreaseHighestReceivedOffset(frame.byte_offset);
 193
 194   stream_error_ = frame.error_code;
 195   CloseWriteSide();
 196   CloseReadSide();
 197 }
 198
 199 void ReliableQuicStream::OnConnectionClosed(QuicErrorCode error,
 200                                             bool from_peer) {
 201   if (read_side_closed_ && write_side_closed_) {
 202     return;
 203   }
 204   if (error != QUIC_NO_ERROR) {
 205     stream_error_ = QUIC_STREAM_CONNECTION_ERROR;
 206     connection_error_ = error;
 207   }
 208
 209   CloseWriteSide();
 210   CloseReadSide();
 211 }
 212
 213 void ReliableQuicStream::OnFinRead() {
 214   DCHECK(sequencer_.IsClosed());
 215   fin_received_ = true;
 216   CloseReadSide();
 217 }
 218
 219 void ReliableQuicStream::Reset(QuicRstStreamErrorCode error) {
 220   DCHECK_NE(QUIC_STREAM_NO_ERROR, error);
 221   stream_error_ = error;
 222   // Sending a RstStream results in calling CloseStream.
 223   session()->SendRstStream(id(), error, stream_bytes_written_);
 224   rst_sent_ = true;
 225 }
 226
 227 void ReliableQuicStream::CloseConnection(QuicErrorCode error) {
 228   session()->connection()->SendConnectionClose(error);
 229 }
 230
 231 void ReliableQuicStream::CloseConnectionWithDetails(QuicErrorCode error,
 232                                                     const string& details) {
 233   session()->connection()->SendConnectionCloseWithDetails(error, details);
 234 }
 235
 236 void ReliableQuicStream::WriteOrBufferData(
 237     StringPiece data,
 238     bool fin,
 239     QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
 240   if (data.empty() && !fin) {
 241     LOG(DFATAL) << "data.empty() && !fin";
 242     return;
 243   }
 244
 245   if (fin_buffered_) {
 246     LOG(DFATAL) << "Fin already buffered";
 247     return;
 248   }
 249
 250   scoped_refptr<ProxyAckNotifierDelegate> proxy_delegate;
 251   if (ack_notifier_delegate != nullptr) {
 252     proxy_delegate = new ProxyAckNotifierDelegate(ack_notifier_delegate);
 253   }
 254
 255   QuicConsumedData consumed_data(0, false);
 256   fin_buffered_ = fin;
 257
 258   if (queued_data_.empty()) {
 259     struct iovec iov(MakeIovec(data));
 260     consumed_data = WritevData(&iov, 1, fin, proxy_delegate.get());
 261     DCHECK_LE(consumed_data.bytes_consumed, data.length());
 262   }
 263
 264   bool write_completed;
 265   // If there's unconsumed data or an unconsumed fin, queue it.
 266   if (consumed_data.bytes_consumed < data.length() ||
 267       (fin && !consumed_data.fin_consumed)) {
 268     StringPiece remainder(data.substr(consumed_data.bytes_consumed));
 269     queued_data_.push_back(PendingData(remainder.as_string(), proxy_delegate));
 270     write_completed = false;
 271   } else {
 272     write_completed = true;
 273   }
 274
 275   if ((proxy_delegate.get() != nullptr) &&
 276       (consumed_data.bytes_consumed > 0 || consumed_data.fin_consumed)) {
 277     proxy_delegate->WroteData(write_completed);
 278   }
 279 }
 280
 281 void ReliableQuicStream::OnCanWrite() {
 282   bool fin = false;
 283   while (!queued_data_.empty()) {
 284     PendingData* pending_data = &queued_data_.front();
 285     ProxyAckNotifierDelegate* delegate = pending_data->delegate.get();
 286     if (queued_data_.size() == 1 && fin_buffered_) {
 287       fin = true;
 288     }
 289     struct iovec iov(MakeIovec(pending_data->data));
 290     QuicConsumedData consumed_data = WritevData(&iov, 1, fin, delegate);
 291     if (consumed_data.bytes_consumed == pending_data->data.size() &&
 292         fin == consumed_data.fin_consumed) {
 293       queued_data_.pop_front();
 294       if (delegate != nullptr) {
 295         delegate->WroteData(true);
 296       }
 297     } else {
 298       if (consumed_data.bytes_consumed > 0) {
 299         pending_data->data.erase(0, consumed_data.bytes_consumed);
 300         if (delegate != nullptr) {
 301           delegate->WroteData(false);
 302         }
 303       }
 304       break;
 305     }
 306   }
 307 }
 308
 309 void ReliableQuicStream::MaybeSendBlocked() {
 310   flow_controller_.MaybeSendBlocked();
 311   if (!stream_contributes_to_connection_flow_control_) {
 312     return;
 313   }
 314   connection_flow_controller_->MaybeSendBlocked();
 315   // If we are connection level flow control blocked, then add the stream
 316   // to the write blocked list. It will be given a chance to write when a
 317   // connection level WINDOW_UPDATE arrives.
 318   if (connection_flow_controller_->IsBlocked() &&
 319       !flow_controller_.IsBlocked()) {
 320     session_->MarkWriteBlocked(id(), EffectivePriority());
 321   }
 322 }
 323
 324 QuicConsumedData ReliableQuicStream::WritevData(
 325     const struct iovec* iov,
 326     int iov_count,
 327     bool fin,
 328     QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
 329   if (write_side_closed_) {
 330     DLOG(ERROR) << ENDPOINT << "Attempt to write when the write side is closed";
 331     return QuicConsumedData(0, false);
 332   }
 333
 334   // How much data we want to write.
 335   size_t write_length = TotalIovecLength(iov, iov_count);
 336
 337   // A FIN with zero data payload should not be flow control blocked.
 338   bool fin_with_zero_data = (fin && write_length == 0);
 339
 340   // How much data we are allowed to write from flow control.
 341   QuicByteCount send_window = flow_controller_.SendWindowSize();
 342   if (stream_contributes_to_connection_flow_control_) {
 343     send_window =
 344         min(send_window, connection_flow_controller_->SendWindowSize());
 345   }
 346
 347   if (send_window == 0 && !fin_with_zero_data) {
 348     // Quick return if we can't send anything.
 349     MaybeSendBlocked();
 350     return QuicConsumedData(0, false);
 351   }
 352
 353   if (write_length > send_window) {
 354     // Don't send the FIN if we aren't going to send all the data.
 355     fin = false;
 356
 357     // Writing more data would be a violation of flow control.
 358     write_length = static_cast<size_t>(send_window);
 359   }
 360
 361   // Fill an IOVector with bytes from the iovec.
 362   IOVector data;
 363   data.AppendIovecAtMostBytes(iov, iov_count, write_length);
 364
 365   QuicConsumedData consumed_data = session()->WritevData(
 366       id(), data, stream_bytes_written_, fin, GetFecProtection(),
 367       ack_notifier_delegate);
 368   stream_bytes_written_ += consumed_data.bytes_consumed;
 369
 370   AddBytesSent(consumed_data.bytes_consumed);
 371
 372   if (consumed_data.bytes_consumed == write_length) {
 373     if (!fin_with_zero_data) {
 374       MaybeSendBlocked();
 375     }
 376     if (fin && consumed_data.fin_consumed) {
 377       fin_sent_ = true;
 378       CloseWriteSide();
 379     } else if (fin && !consumed_data.fin_consumed) {
 380       session_->MarkWriteBlocked(id(), EffectivePriority());
 381     }
 382   } else {
 383     session_->MarkWriteBlocked(id(), EffectivePriority());
 384   }
 385   return consumed_data;
 386 }
 387
 388 FecProtection ReliableQuicStream::GetFecProtection() {
 389   return fec_policy_ == FEC_PROTECT_ALWAYS ? MUST_FEC_PROTECT : MAY_FEC_PROTECT;
 390 }
 391
 392 void ReliableQuicStream::CloseReadSide() {
 393   if (read_side_closed_) {
 394     return;
 395   }
 396   DVLOG(1) << ENDPOINT << "Done reading from stream " << id();
 397
 398   read_side_closed_ = true;
 399   if (write_side_closed_) {
 400     DVLOG(1) << ENDPOINT << "Closing stream: " << id();
 401     session_->CloseStream(id());
 402   }
 403 }
 404
 405 void ReliableQuicStream::CloseWriteSide() {
 406   if (write_side_closed_) {
 407     return;
 408   }
 409   DVLOG(1) << ENDPOINT << "Done writing to stream " << id();
 410
 411   write_side_closed_ = true;
 412   if (read_side_closed_) {
 413     DVLOG(1) << ENDPOINT << "Closing stream: " << id();
 414     session_->CloseStream(id());
 415   }
 416 }
 417
 418 bool ReliableQuicStream::HasBufferedData() const {
 419   return !queued_data_.empty();
 420 }
 421
 422 void ReliableQuicStream::OnClose() {
 423   CloseReadSide();
 424   CloseWriteSide();
 425
 426   if (!fin_sent_ && !rst_sent_) {
 427     // For flow control accounting, we must tell the peer how many bytes we have
 428     // written on this stream before termination. Done here if needed, using a
 429     // RST frame.
 430     DVLOG(1) << ENDPOINT << "Sending RST in OnClose: " << id();
 431     session_->SendRstStream(id(), QUIC_RST_ACKNOWLEDGEMENT,
 432                             stream_bytes_written_);
 433     rst_sent_ = true;
 434   }
 435
 436   // We are closing the stream and will not process any further incoming bytes.
 437   // As there may be more bytes in flight and we need to ensure that both
 438   // endpoints have the same connection level flow control state, mark all
 439   // unreceived or buffered bytes as consumed.
 440   QuicByteCount bytes_to_consume =
 441       flow_controller_.highest_received_byte_offset() -
 442       flow_controller_.bytes_consumed();
 443   AddBytesConsumed(bytes_to_consume);
 444 }
 445
 446 void ReliableQuicStream::OnWindowUpdateFrame(
 447     const QuicWindowUpdateFrame& frame) {
 448   if (flow_controller_.UpdateSendWindowOffset(frame.byte_offset)) {
 449     // We can write again!
 450     // TODO(rjshade): This does not respect priorities (e.g. multiple
 451     //                outstanding POSTs are unblocked on arrival of
 452     //                SHLO with initial window).
 453     // As long as the connection is not flow control blocked, we can write!
 454     OnCanWrite();
 455   }
 456 }
 457
 458 bool ReliableQuicStream::MaybeIncreaseHighestReceivedOffset(
 459     QuicStreamOffset new_offset) {
 460   uint64 increment =
 461       new_offset - flow_controller_.highest_received_byte_offset();
 462   if (!flow_controller_.UpdateHighestReceivedOffset(new_offset)) {
 463     return false;
 464   }
 465
 466   // If |new_offset| increased the stream flow controller's highest received
 467   // offset, then we need to increase the connection flow controller's value
 468   // by the incremental difference.
 469   if (stream_contributes_to_connection_flow_control_) {
 470     connection_flow_controller_->UpdateHighestReceivedOffset(
 471         connection_flow_controller_->highest_received_byte_offset() +
 472         increment);
 473   }
 474   return true;
 475 }
 476
 477 void ReliableQuicStream::AddBytesSent(QuicByteCount bytes) {
 478   flow_controller_.AddBytesSent(bytes);
 479   if (stream_contributes_to_connection_flow_control_) {
 480     connection_flow_controller_->AddBytesSent(bytes);
 481   }
 482 }
 483
 484 void ReliableQuicStream::AddBytesConsumed(QuicByteCount bytes) {
 485   // Only adjust stream level flow controller if we are still reading.
 486   if (!read_side_closed_) {
 487     flow_controller_.AddBytesConsumed(bytes);
 488   }
 489
 490   if (stream_contributes_to_connection_flow_control_) {
 491     connection_flow_controller_->AddBytesConsumed(bytes);
 492   }
 493 }
 494
 495 void ReliableQuicStream::UpdateSendWindowOffset(QuicStreamOffset new_window) {
 496   if (flow_controller_.UpdateSendWindowOffset(new_window)) {
 497     OnCanWrite();
 498   }
 499 }
 500
 501 }  // namespace net