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
  16 namespace net {
  17
  18 #define ENDPOINT (is_server_ ? "Server: " : " Client: ")
  19
  20 namespace {
  21
  22 struct iovec MakeIovec(StringPiece data) {
  23   struct iovec iov = {const_cast<char*>(data.data()),
  24                       static_cast<size_t>(data.size())};
  25   return iov;
  26 }
  27
  28 size_t GetInitialStreamFlowControlWindowToSend(QuicSession* session) {
  29   QuicVersion version = session->connection()->version();
  30   if (version <= QUIC_VERSION_19) {
  31     return session->config()->GetInitialFlowControlWindowToSend();
  32   }
  33
  34   return session->config()->GetInitialStreamFlowControlWindowToSend();
  35 }
  36
  37 size_t GetReceivedFlowControlWindow(QuicSession* session) {
  38   QuicVersion version = session->connection()->version();
  39   if (version <= QUIC_VERSION_19) {
  40     if (session->config()->HasReceivedInitialFlowControlWindowBytes()) {
  41       return session->config()->ReceivedInitialFlowControlWindowBytes();
  42     }
  43
  44     return kDefaultFlowControlSendWindow;
  45   }
  46
  47   // Version must be >= QUIC_VERSION_20, so we check for stream specific flow
  48   // control window.
  49   if (session->config()->HasReceivedInitialStreamFlowControlWindowBytes()) {
  50     return session->config()->ReceivedInitialStreamFlowControlWindowBytes();
  51   }
  52
  53   return kDefaultFlowControlSendWindow;
  54 }
  55
  56 }  // namespace
  57
  58 // Wrapper that aggregates OnAckNotifications for packets sent using
  59 // WriteOrBufferData and delivers them to the original
  60 // QuicAckNotifier::DelegateInterface after all bytes written using
  61 // WriteOrBufferData are acked.  This level of indirection is
  62 // necessary because the delegate interface provides no mechanism that
  63 // WriteOrBufferData can use to inform it that the write required
  64 // multiple WritevData calls or that only part of the data has been
  65 // sent out by the time ACKs start arriving.
  66 class ReliableQuicStream::ProxyAckNotifierDelegate
  67     : public QuicAckNotifier::DelegateInterface {
  68  public:
  69   explicit ProxyAckNotifierDelegate(DelegateInterface* delegate)
  70       : delegate_(delegate),
  71         pending_acks_(0),
  72         wrote_last_data_(false),
  73         num_original_packets_(0),
  74         num_original_bytes_(0),
  75         num_retransmitted_packets_(0),
  76         num_retransmitted_bytes_(0) {
  77   }
  78
  79   virtual void OnAckNotification(int num_original_packets,
  80                                  int num_original_bytes,
  81                                  int num_retransmitted_packets,
  82                                  int num_retransmitted_bytes,
  83                                  QuicTime::Delta delta_largest_observed)
  84       OVERRIDE {
  85     DCHECK_LT(0, pending_acks_);
  86     --pending_acks_;
  87     num_original_packets_ += num_original_packets;
  88     num_original_bytes_ += num_original_bytes;
  89     num_retransmitted_packets_ += num_retransmitted_packets;
  90     num_retransmitted_bytes_ += num_retransmitted_bytes;
  91
  92     if (wrote_last_data_ && pending_acks_ == 0) {
  93       delegate_->OnAckNotification(num_original_packets_,
  94                                    num_original_bytes_,
  95                                    num_retransmitted_packets_,
  96                                    num_retransmitted_bytes_,
  97                                    delta_largest_observed);
  98     }
  99   }
 100
 101   void WroteData(bool last_data) {
 102     DCHECK(!wrote_last_data_);
 103     ++pending_acks_;
 104     wrote_last_data_ = last_data;
 105   }
 106
 107  protected:
 108   // Delegates are ref counted.
 109   virtual ~ProxyAckNotifierDelegate() OVERRIDE {
 110   }
 111
 112  private:
 113   // Original delegate.  delegate_->OnAckNotification will be called when:
 114   //   wrote_last_data_ == true and pending_acks_ == 0
 115   scoped_refptr<DelegateInterface> delegate_;
 116
 117   // Number of outstanding acks.
 118   int pending_acks_;
 119
 120   // True if no pending writes remain.
 121   bool wrote_last_data_;
 122
 123   // Accumulators.
 124   int num_original_packets_;
 125   int num_original_bytes_;
 126   int num_retransmitted_packets_;
 127   int num_retransmitted_bytes_;
 128
 129   DISALLOW_COPY_AND_ASSIGN(ProxyAckNotifierDelegate);
 130 };
 131
 132 ReliableQuicStream::PendingData::PendingData(
 133     string data_in, scoped_refptr<ProxyAckNotifierDelegate> delegate_in)
 134     : data(data_in), delegate(delegate_in) {
 135 }
 136
 137 ReliableQuicStream::PendingData::~PendingData() {
 138 }
 139
 140 ReliableQuicStream::ReliableQuicStream(QuicStreamId id, QuicSession* session)
 141     : sequencer_(this),
 142       id_(id),
 143       session_(session),
 144       stream_bytes_read_(0),
 145       stream_bytes_written_(0),
 146       stream_error_(QUIC_STREAM_NO_ERROR),
 147       connection_error_(QUIC_NO_ERROR),
 148       read_side_closed_(false),
 149       write_side_closed_(false),
 150       fin_buffered_(false),
 151       fin_sent_(false),
 152       fin_received_(false),
 153       rst_sent_(false),
 154       rst_received_(false),
 155       fec_policy_(FEC_PROTECT_OPTIONAL),
 156       is_server_(session_->is_server()),
 157       flow_controller_(
 158           session_->connection(), id_, is_server_,
 159           GetReceivedFlowControlWindow(session),
 160           GetInitialStreamFlowControlWindowToSend(session),
 161           GetInitialStreamFlowControlWindowToSend(session)),
 162       connection_flow_controller_(session_->flow_controller()),
 163       stream_contributes_to_connection_flow_control_(true) {
 164 }
 165
 166 ReliableQuicStream::~ReliableQuicStream() {
 167 }
 168
 169 bool ReliableQuicStream::OnStreamFrame(const QuicStreamFrame& frame) {
 170   if (read_side_closed_) {
 171     DVLOG(1) << ENDPOINT << "Ignoring frame " << frame.stream_id;
 172     // We don't want to be reading: blackhole the data.
 173     return true;
 174   }
 175
 176   if (frame.stream_id != id_) {
 177     LOG(ERROR) << "Error!";
 178     return false;
 179   }
 180
 181   if (frame.fin) {
 182     fin_received_ = true;
 183   }
 184
 185   // This count include duplicate data received.
 186   size_t frame_payload_size = frame.data.TotalBufferSize();
 187   stream_bytes_read_ += frame_payload_size;
 188
 189   // Flow control is interested in tracking highest received offset.
 190   if (MaybeIncreaseHighestReceivedOffset(frame.offset + frame_payload_size)) {
 191     // As the highest received offset has changed, we should check to see if
 192     // this is a violation of flow control.
 193     if (flow_controller_.FlowControlViolation() ||
 194         connection_flow_controller_->FlowControlViolation()) {
 195       session_->connection()->SendConnectionClose(
 196           QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA);
 197       return false;
 198     }
 199   }
 200
 201   return sequencer_.OnStreamFrame(frame);
 202 }
 203
 204 int ReliableQuicStream::num_frames_received() const {
 205   return sequencer_.num_frames_received();
 206 }
 207
 208 int ReliableQuicStream::num_duplicate_frames_received() const {
 209   return sequencer_.num_duplicate_frames_received();
 210 }
 211
 212 void ReliableQuicStream::OnStreamReset(const QuicRstStreamFrame& frame) {
 213   rst_received_ = true;
 214   MaybeIncreaseHighestReceivedOffset(frame.byte_offset);
 215
 216   stream_error_ = frame.error_code;
 217   CloseWriteSide();
 218   CloseReadSide();
 219 }
 220
 221 void ReliableQuicStream::OnConnectionClosed(QuicErrorCode error,
 222                                             bool from_peer) {
 223   if (read_side_closed_ && write_side_closed_) {
 224     return;
 225   }
 226   if (error != QUIC_NO_ERROR) {
 227     stream_error_ = QUIC_STREAM_CONNECTION_ERROR;
 228     connection_error_ = error;
 229   }
 230
 231   CloseWriteSide();
 232   CloseReadSide();
 233 }
 234
 235 void ReliableQuicStream::OnFinRead() {
 236   DCHECK(sequencer_.IsClosed());
 237   CloseReadSide();
 238 }
 239
 240 void ReliableQuicStream::Reset(QuicRstStreamErrorCode error) {
 241   DCHECK_NE(QUIC_STREAM_NO_ERROR, error);
 242   stream_error_ = error;
 243   // Sending a RstStream results in calling CloseStream.
 244   session()->SendRstStream(id(), error, stream_bytes_written_);
 245   rst_sent_ = true;
 246 }
 247
 248 void ReliableQuicStream::CloseConnection(QuicErrorCode error) {
 249   session()->connection()->SendConnectionClose(error);
 250 }
 251
 252 void ReliableQuicStream::CloseConnectionWithDetails(QuicErrorCode error,
 253                                                     const string& details) {
 254   session()->connection()->SendConnectionCloseWithDetails(error, details);
 255 }
 256
 257 QuicVersion ReliableQuicStream::version() const {
 258   return session()->connection()->version();
 259 }
 260
 261 void ReliableQuicStream::WriteOrBufferData(
 262     StringPiece data,
 263     bool fin,
 264     QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
 265   if (data.empty() && !fin) {
 266     LOG(DFATAL) << "data.empty() && !fin";
 267     return;
 268   }
 269
 270   if (fin_buffered_) {
 271     LOG(DFATAL) << "Fin already buffered";
 272     return;
 273   }
 274
 275   scoped_refptr<ProxyAckNotifierDelegate> proxy_delegate;
 276   if (ack_notifier_delegate != NULL) {
 277     proxy_delegate = new ProxyAckNotifierDelegate(ack_notifier_delegate);
 278   }
 279
 280   QuicConsumedData consumed_data(0, false);
 281   fin_buffered_ = fin;
 282
 283   if (queued_data_.empty()) {
 284     struct iovec iov(MakeIovec(data));
 285     consumed_data = WritevData(&iov, 1, fin, proxy_delegate.get());
 286     DCHECK_LE(consumed_data.bytes_consumed, data.length());
 287   }
 288
 289   bool write_completed;
 290   // If there's unconsumed data or an unconsumed fin, queue it.
 291   if (consumed_data.bytes_consumed < data.length() ||
 292       (fin && !consumed_data.fin_consumed)) {
 293     StringPiece remainder(data.substr(consumed_data.bytes_consumed));
 294     queued_data_.push_back(PendingData(remainder.as_string(), proxy_delegate));
 295     write_completed = false;
 296   } else {
 297     write_completed = true;
 298   }
 299
 300   if ((proxy_delegate.get() != NULL) &&
 301       (consumed_data.bytes_consumed > 0 || consumed_data.fin_consumed)) {
 302     proxy_delegate->WroteData(write_completed);
 303   }
 304 }
 305
 306 void ReliableQuicStream::OnCanWrite() {
 307   bool fin = false;
 308   while (!queued_data_.empty()) {
 309     PendingData* pending_data = &queued_data_.front();
 310     ProxyAckNotifierDelegate* delegate = pending_data->delegate.get();
 311     if (queued_data_.size() == 1 && fin_buffered_) {
 312       fin = true;
 313     }
 314     struct iovec iov(MakeIovec(pending_data->data));
 315     QuicConsumedData consumed_data = WritevData(&iov, 1, fin, delegate);
 316     if (consumed_data.bytes_consumed == pending_data->data.size() &&
 317         fin == consumed_data.fin_consumed) {
 318       queued_data_.pop_front();
 319       if (delegate != NULL) {
 320         delegate->WroteData(true);
 321       }
 322     } else {
 323       if (consumed_data.bytes_consumed > 0) {
 324         pending_data->data.erase(0, consumed_data.bytes_consumed);
 325         if (delegate != NULL) {
 326           delegate->WroteData(false);
 327         }
 328       }
 329       break;
 330     }
 331   }
 332 }
 333
 334 void ReliableQuicStream::MaybeSendBlocked() {
 335   flow_controller_.MaybeSendBlocked();
 336   if (!stream_contributes_to_connection_flow_control_) {
 337     return;
 338   }
 339   connection_flow_controller_->MaybeSendBlocked();
 340   // If we are connection level flow control blocked, then add the stream
 341   // to the write blocked list. It will be given a chance to write when a
 342   // connection level WINDOW_UPDATE arrives.
 343   if (connection_flow_controller_->IsBlocked() &&
 344       !flow_controller_.IsBlocked()) {
 345     session_->MarkWriteBlocked(id(), EffectivePriority());
 346   }
 347 }
 348
 349 QuicConsumedData ReliableQuicStream::WritevData(
 350     const struct iovec* iov,
 351     int iov_count,
 352     bool fin,
 353     QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
 354   if (write_side_closed_) {
 355     DLOG(ERROR) << ENDPOINT << "Attempt to write when the write side is closed";
 356     return QuicConsumedData(0, false);
 357   }
 358
 359   // How much data we want to write.
 360   size_t write_length = TotalIovecLength(iov, iov_count);
 361
 362   // A FIN with zero data payload should not be flow control blocked.
 363   bool fin_with_zero_data = (fin && write_length == 0);
 364
 365   if (flow_controller_.IsEnabled()) {
 366     // How much data we are allowed to write from flow control.
 367     uint64 send_window = flow_controller_.SendWindowSize();
 368     // TODO(rjshade): Remove connection_flow_controller_->IsEnabled() check when
 369     // removing QUIC_VERSION_19.
 370     if (stream_contributes_to_connection_flow_control_ &&
 371         connection_flow_controller_->IsEnabled()) {
 372       send_window =
 373           min(send_window, connection_flow_controller_->SendWindowSize());
 374     }
 375
 376     if (send_window == 0 && !fin_with_zero_data) {
 377       // Quick return if we can't send anything.
 378       MaybeSendBlocked();
 379       return QuicConsumedData(0, false);
 380     }
 381
 382     if (write_length > send_window) {
 383       // Don't send the FIN if we aren't going to send all the data.
 384       fin = false;
 385
 386       // Writing more data would be a violation of flow control.
 387       write_length = send_window;
 388     }
 389   }
 390
 391   // Fill an IOVector with bytes from the iovec.
 392   IOVector data;
 393   data.AppendIovecAtMostBytes(iov, iov_count, write_length);
 394
 395   QuicConsumedData consumed_data = session()->WritevData(
 396       id(), data, stream_bytes_written_, fin, GetFecProtection(),
 397       ack_notifier_delegate);
 398   stream_bytes_written_ += consumed_data.bytes_consumed;
 399
 400   AddBytesSent(consumed_data.bytes_consumed);
 401
 402   if (consumed_data.bytes_consumed == write_length) {
 403     if (!fin_with_zero_data) {
 404       MaybeSendBlocked();
 405     }
 406     if (fin && consumed_data.fin_consumed) {
 407       fin_sent_ = true;
 408       CloseWriteSide();
 409     } else if (fin && !consumed_data.fin_consumed) {
 410       session_->MarkWriteBlocked(id(), EffectivePriority());
 411     }
 412   } else {
 413     session_->MarkWriteBlocked(id(), EffectivePriority());
 414   }
 415   return consumed_data;
 416 }
 417
 418 FecProtection ReliableQuicStream::GetFecProtection() {
 419   return fec_policy_ == FEC_PROTECT_ALWAYS ? MUST_FEC_PROTECT : MAY_FEC_PROTECT;
 420 }
 421
 422 void ReliableQuicStream::CloseReadSide() {
 423   if (read_side_closed_) {
 424     return;
 425   }
 426   DVLOG(1) << ENDPOINT << "Done reading from stream " << id();
 427
 428   read_side_closed_ = true;
 429   if (write_side_closed_) {
 430     DVLOG(1) << ENDPOINT << "Closing stream: " << id();
 431     session_->CloseStream(id());
 432   }
 433 }
 434
 435 void ReliableQuicStream::CloseWriteSide() {
 436   if (write_side_closed_) {
 437     return;
 438   }
 439   DVLOG(1) << ENDPOINT << "Done writing to stream " << id();
 440
 441   write_side_closed_ = true;
 442   if (read_side_closed_) {
 443     DVLOG(1) << ENDPOINT << "Closing stream: " << id();
 444     session_->CloseStream(id());
 445   }
 446 }
 447
 448 bool ReliableQuicStream::HasBufferedData() const {
 449   return !queued_data_.empty();
 450 }
 451
 452 void ReliableQuicStream::OnClose() {
 453   CloseReadSide();
 454   CloseWriteSide();
 455
 456   if (!fin_sent_ && !rst_sent_) {
 457     // For flow control accounting, we must tell the peer how many bytes we have
 458     // written on this stream before termination. Done here if needed, using a
 459     // RST frame.
 460     DVLOG(1) << ENDPOINT << "Sending RST in OnClose: " << id();
 461     session_->SendRstStream(id(), QUIC_RST_FLOW_CONTROL_ACCOUNTING,
 462                             stream_bytes_written_);
 463     rst_sent_ = true;
 464   }
 465
 466   // We are closing the stream and will not process any further incoming bytes.
 467   // As there may be more bytes in flight and we need to ensure that both
 468   // endpoints have the same connection level flow control state, mark all
 469   // unreceived or buffered bytes as consumed.
 470   uint64 bytes_to_consume = flow_controller_.highest_received_byte_offset() -
 471       flow_controller_.bytes_consumed();
 472   AddBytesConsumed(bytes_to_consume);
 473 }
 474
 475 void ReliableQuicStream::OnWindowUpdateFrame(
 476     const QuicWindowUpdateFrame& frame) {
 477   if (!flow_controller_.IsEnabled()) {
 478     DLOG(DFATAL) << "Flow control not enabled! " << version();
 479     return;
 480   }
 481
 482   if (flow_controller_.UpdateSendWindowOffset(frame.byte_offset)) {
 483     // We can write again!
 484     // TODO(rjshade): This does not respect priorities (e.g. multiple
 485     //                outstanding POSTs are unblocked on arrival of
 486     //                SHLO with initial window).
 487     // As long as the connection is not flow control blocked, we can write!
 488     OnCanWrite();
 489   }
 490 }
 491
 492 bool ReliableQuicStream::MaybeIncreaseHighestReceivedOffset(uint64 new_offset) {
 493   if (!flow_controller_.IsEnabled()) {
 494     return false;
 495   }
 496   uint64 increment =
 497       new_offset - flow_controller_.highest_received_byte_offset();
 498   if (!flow_controller_.UpdateHighestReceivedOffset(new_offset)) {
 499     return false;
 500   }
 501
 502   // If |new_offset| increased the stream flow controller's highest received
 503   // offset, then we need to increase the connection flow controller's value
 504   // by the incremental difference.
 505   if (stream_contributes_to_connection_flow_control_) {
 506     connection_flow_controller_->UpdateHighestReceivedOffset(
 507         connection_flow_controller_->highest_received_byte_offset() +
 508         increment);
 509   }
 510   return true;
 511 }
 512
 513 void ReliableQuicStream::AddBytesSent(uint64 bytes) {
 514   if (flow_controller_.IsEnabled()) {
 515     flow_controller_.AddBytesSent(bytes);
 516     if (stream_contributes_to_connection_flow_control_) {
 517       connection_flow_controller_->AddBytesSent(bytes);
 518     }
 519   }
 520 }
 521
 522 void ReliableQuicStream::AddBytesConsumed(uint64 bytes) {
 523   if (flow_controller_.IsEnabled()) {
 524     // Only adjust stream level flow controller if we are still reading.
 525     if (!read_side_closed_) {
 526       flow_controller_.AddBytesConsumed(bytes);
 527     }
 528
 529     if (stream_contributes_to_connection_flow_control_) {
 530       connection_flow_controller_->AddBytesConsumed(bytes);
 531     }
 532   }
 533 }
 534
 535 bool ReliableQuicStream::IsFlowControlBlocked() {
 536   if (flow_controller_.IsBlocked()) {
 537     return true;
 538   }
 539   return stream_contributes_to_connection_flow_control_ &&
 540       connection_flow_controller_->IsBlocked();
 541 }
 542
 543 }  // namespace net