reliable_quic_stream.cc revision 46d4c2bc3267f3f028f39e7e311b0f89aba2e4fd 
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
13using base::StringPiece;
14using std::min;
15
16namespace net {
17
18#define ENDPOINT (is_server_ ? "Server: " : " Client: ")
19
20namespace {
21
22struct 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}  // namespace
29
30// Wrapper that aggregates OnAckNotifications for packets sent using
31// WriteOrBufferData and delivers them to the original
32// QuicAckNotifier::DelegateInterface after all bytes written using
33// WriteOrBufferData are acked.  This level of indirection is
34// necessary because the delegate interface provides no mechanism that
35// WriteOrBufferData can use to inform it that the write required
36// multiple WritevData calls or that only part of the data has been
37// sent out by the time ACKs start arriving.
38class ReliableQuicStream::ProxyAckNotifierDelegate
39    : public QuicAckNotifier::DelegateInterface {
40 public:
41  explicit ProxyAckNotifierDelegate(DelegateInterface* delegate)
42      : delegate_(delegate),
43        pending_acks_(0),
44        wrote_last_data_(false),
45        num_original_packets_(0),
46        num_original_bytes_(0),
47        num_retransmitted_packets_(0),
48        num_retransmitted_bytes_(0) {
49  }
50
51  virtual void OnAckNotification(int num_original_packets,
52                                 int num_original_bytes,
53                                 int num_retransmitted_packets,
54                                 int num_retransmitted_bytes,
55                                 QuicTime::Delta delta_largest_observed)
56      OVERRIDE {
57    DCHECK_LT(0, pending_acks_);
58    --pending_acks_;
59    num_original_packets_ += num_original_packets;
60    num_original_bytes_ += num_original_bytes;
61    num_retransmitted_packets_ += num_retransmitted_packets;
62    num_retransmitted_bytes_ += num_retransmitted_bytes;
63
64    if (wrote_last_data_ && pending_acks_ == 0) {
65      delegate_->OnAckNotification(num_original_packets_,
66                                   num_original_bytes_,
67                                   num_retransmitted_packets_,
68                                   num_retransmitted_bytes_,
69                                   delta_largest_observed);
70    }
71  }
72
73  void WroteData(bool last_data) {
74    DCHECK(!wrote_last_data_);
75    ++pending_acks_;
76    wrote_last_data_ = last_data;
77  }
78
79 protected:
80  // Delegates are ref counted.
81  virtual ~ProxyAckNotifierDelegate() {
82  }
83
84 private:
85  // Original delegate.  delegate_->OnAckNotification will be called when:
86  //   wrote_last_data_ == true and pending_acks_ == 0
87  scoped_refptr<DelegateInterface> delegate_;
88
89  // Number of outstanding acks.
90  int pending_acks_;
91
92  // True if no pending writes remain.
93  bool wrote_last_data_;
94
95  // Accumulators.
96  int num_original_packets_;
97  int num_original_bytes_;
98  int num_retransmitted_packets_;
99  int num_retransmitted_bytes_;
100
101  DISALLOW_COPY_AND_ASSIGN(ProxyAckNotifierDelegate);
102};
103
104ReliableQuicStream::PendingData::PendingData(
105    string data_in, scoped_refptr<ProxyAckNotifierDelegate> delegate_in)
106    : data(data_in), delegate(delegate_in) {
107}
108
109ReliableQuicStream::PendingData::~PendingData() {
110}
111
112ReliableQuicStream::ReliableQuicStream(QuicStreamId id, QuicSession* session)
113    : sequencer_(this),
114      id_(id),
115      session_(session),
116      stream_bytes_read_(0),
117      stream_bytes_written_(0),
118      stream_error_(QUIC_STREAM_NO_ERROR),
119      connection_error_(QUIC_NO_ERROR),
120      read_side_closed_(false),
121      write_side_closed_(false),
122      fin_buffered_(false),
123      fin_sent_(false),
124      rst_sent_(false),
125      is_server_(session_->is_server()),
126      flow_controller_(
127          session_->connection(),
128          id_,
129          is_server_,
130          session_->config()->HasReceivedInitialFlowControlWindowBytes() ?
131              session_->config()->ReceivedInitialFlowControlWindowBytes() :
132              kDefaultFlowControlSendWindow,
133          session_->max_flow_control_receive_window_bytes(),
134          session_->max_flow_control_receive_window_bytes()),
135      connection_flow_controller_(session_->flow_controller()) {
136}
137
138ReliableQuicStream::~ReliableQuicStream() {
139}
140
141bool ReliableQuicStream::OnStreamFrame(const QuicStreamFrame& frame) {
142  if (read_side_closed_) {
143    DVLOG(1) << ENDPOINT << "Ignoring frame " << frame.stream_id;
144    // We don't want to be reading: blackhole the data.
145    return true;
146  }
147
148  if (frame.stream_id != id_) {
149    LOG(ERROR) << "Error!";
150    return false;
151  }
152
153  // This count include duplicate data received.
154  size_t frame_payload_size = frame.data.TotalBufferSize();
155  stream_bytes_read_ += frame_payload_size;
156
157  // Flow control is interested in tracking highest received offset.
158  if (MaybeIncreaseHighestReceivedOffset(frame.offset + frame_payload_size)) {
159    // As the highest received offset has changed, we should check to see if
160    // this is a violation of flow control.
161    if (flow_controller_.FlowControlViolation() ||
162        connection_flow_controller_->FlowControlViolation()) {
163      session_->connection()->SendConnectionClose(
164          QUIC_FLOW_CONTROL_RECEIVED_TOO_MUCH_DATA);
165      return false;
166    }
167  }
168
169  return sequencer_.OnStreamFrame(frame);
170}
171
172int ReliableQuicStream::num_frames_received() const {
173  return sequencer_.num_frames_received();
174}
175
176int ReliableQuicStream::num_duplicate_frames_received() const {
177  return sequencer_.num_duplicate_frames_received();
178}
179
180void ReliableQuicStream::OnStreamReset(const QuicRstStreamFrame& frame) {
181  MaybeIncreaseHighestReceivedOffset(frame.byte_offset);
182
183  stream_error_ = frame.error_code;
184  CloseWriteSide();
185  CloseReadSide();
186}
187
188void ReliableQuicStream::OnConnectionClosed(QuicErrorCode error,
189                                            bool from_peer) {
190  if (read_side_closed_ && write_side_closed_) {
191    return;
192  }
193  if (error != QUIC_NO_ERROR) {
194    stream_error_ = QUIC_STREAM_CONNECTION_ERROR;
195    connection_error_ = error;
196  }
197
198  CloseWriteSide();
199  CloseReadSide();
200}
201
202void ReliableQuicStream::OnFinRead() {
203  DCHECK(sequencer_.IsClosed());
204  CloseReadSide();
205}
206
207void ReliableQuicStream::Reset(QuicRstStreamErrorCode error) {
208  DCHECK_NE(QUIC_STREAM_NO_ERROR, error);
209  stream_error_ = error;
210  // Sending a RstStream results in calling CloseStream.
211  session()->SendRstStream(id(), error, stream_bytes_written_);
212  rst_sent_ = true;
213}
214
215void ReliableQuicStream::CloseConnection(QuicErrorCode error) {
216  session()->connection()->SendConnectionClose(error);
217}
218
219void ReliableQuicStream::CloseConnectionWithDetails(QuicErrorCode error,
220                                                    const string& details) {
221  session()->connection()->SendConnectionCloseWithDetails(error, details);
222}
223
224QuicVersion ReliableQuicStream::version() const {
225  return session()->connection()->version();
226}
227
228void ReliableQuicStream::WriteOrBufferData(
229    StringPiece data,
230    bool fin,
231    QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
232  if (data.empty() && !fin) {
233    LOG(DFATAL) << "data.empty() && !fin";
234    return;
235  }
236
237  if (fin_buffered_) {
238    LOG(DFATAL) << "Fin already buffered";
239    return;
240  }
241
242  scoped_refptr<ProxyAckNotifierDelegate> proxy_delegate;
243  if (ack_notifier_delegate != NULL) {
244    proxy_delegate = new ProxyAckNotifierDelegate(ack_notifier_delegate);
245  }
246
247  QuicConsumedData consumed_data(0, false);
248  fin_buffered_ = fin;
249
250  if (queued_data_.empty()) {
251    struct iovec iov(MakeIovec(data));
252    consumed_data = WritevData(&iov, 1, fin, proxy_delegate.get());
253    DCHECK_LE(consumed_data.bytes_consumed, data.length());
254  }
255
256  bool write_completed;
257  // If there's unconsumed data or an unconsumed fin, queue it.
258  if (consumed_data.bytes_consumed < data.length() ||
259      (fin && !consumed_data.fin_consumed)) {
260    StringPiece remainder(data.substr(consumed_data.bytes_consumed));
261    queued_data_.push_back(PendingData(remainder.as_string(), proxy_delegate));
262    write_completed = false;
263  } else {
264    write_completed = true;
265  }
266
267  if ((proxy_delegate.get() != NULL) &&
268      (consumed_data.bytes_consumed > 0 || consumed_data.fin_consumed)) {
269    proxy_delegate->WroteData(write_completed);
270  }
271}
272
273void ReliableQuicStream::OnCanWrite() {
274  bool fin = false;
275  while (!queued_data_.empty()) {
276    PendingData* pending_data = &queued_data_.front();
277    ProxyAckNotifierDelegate* delegate = pending_data->delegate.get();
278    if (queued_data_.size() == 1 && fin_buffered_) {
279      fin = true;
280    }
281    struct iovec iov(MakeIovec(pending_data->data));
282    QuicConsumedData consumed_data = WritevData(&iov, 1, fin, delegate);
283    if (consumed_data.bytes_consumed == pending_data->data.size() &&
284        fin == consumed_data.fin_consumed) {
285      queued_data_.pop_front();
286      if (delegate != NULL) {
287        delegate->WroteData(true);
288      }
289    } else {
290      if (consumed_data.bytes_consumed > 0) {
291        pending_data->data.erase(0, consumed_data.bytes_consumed);
292        if (delegate != NULL) {
293          delegate->WroteData(false);
294        }
295      }
296      break;
297    }
298  }
299}
300
301void ReliableQuicStream::MaybeSendBlocked() {
302  flow_controller_.MaybeSendBlocked();
303  connection_flow_controller_->MaybeSendBlocked();
304  // If we are connection level flow control blocked, then add the stream
305  // to the write blocked list. It will be given a chance to write when a
306  // connection level WINDOW_UPDATE arrives.
307  if (connection_flow_controller_->IsBlocked() &&
308      !flow_controller_.IsBlocked()) {
309    session_->MarkWriteBlocked(id(), EffectivePriority());
310  }
311}
312
313QuicConsumedData ReliableQuicStream::WritevData(
314    const struct iovec* iov,
315    int iov_count,
316    bool fin,
317    QuicAckNotifier::DelegateInterface* ack_notifier_delegate) {
318  if (write_side_closed_) {
319    DLOG(ERROR) << ENDPOINT << "Attempt to write when the write side is closed";
320    return QuicConsumedData(0, false);
321  }
322
323  // How much data we want to write.
324  size_t write_length = TotalIovecLength(iov, iov_count);
325
326  // A FIN with zero data payload should not be flow control blocked.
327  bool fin_with_zero_data = (fin && write_length == 0);
328
329  if (flow_controller_.IsEnabled()) {
330    // How much data we are allowed to write from flow control.
331    uint64 send_window = flow_controller_.SendWindowSize();
332    if (connection_flow_controller_->IsEnabled()) {
333      send_window =
334          min(send_window, connection_flow_controller_->SendWindowSize());
335    }
336
337    if (send_window == 0 && !fin_with_zero_data) {
338      // Quick return if we can't send anything.
339      MaybeSendBlocked();
340      return QuicConsumedData(0, false);
341    }
342
343    if (write_length > send_window) {
344      // Don't send the FIN if we aren't going to send all the data.
345      fin = false;
346
347      // Writing more data would be a violation of flow control.
348      write_length = send_window;
349    }
350  }
351
352  // Fill an IOVector with bytes from the iovec.
353  IOVector data;
354  data.AppendIovecAtMostBytes(iov, iov_count, write_length);
355
356  QuicConsumedData consumed_data = session()->WritevData(
357      id(), data, stream_bytes_written_, fin, ack_notifier_delegate);
358  stream_bytes_written_ += consumed_data.bytes_consumed;
359
360  AddBytesSent(consumed_data.bytes_consumed);
361
362  if (consumed_data.bytes_consumed == write_length) {
363    if (!fin_with_zero_data) {
364      MaybeSendBlocked();
365    }
366    if (fin && consumed_data.fin_consumed) {
367      fin_sent_ = true;
368      CloseWriteSide();
369    } else if (fin && !consumed_data.fin_consumed) {
370      session_->MarkWriteBlocked(id(), EffectivePriority());
371    }
372  } else {
373    session_->MarkWriteBlocked(id(), EffectivePriority());
374  }
375  return consumed_data;
376}
377
378void ReliableQuicStream::CloseReadSide() {
379  if (read_side_closed_) {
380    return;
381  }
382  DVLOG(1) << ENDPOINT << "Done reading from stream " << id();
383
384  read_side_closed_ = true;
385  if (write_side_closed_) {
386    DVLOG(1) << ENDPOINT << "Closing stream: " << id();
387    session_->CloseStream(id());
388  }
389}
390
391void ReliableQuicStream::CloseWriteSide() {
392  if (write_side_closed_) {
393    return;
394  }
395  DVLOG(1) << ENDPOINT << "Done writing to stream " << id();
396
397  write_side_closed_ = true;
398  if (read_side_closed_) {
399    DVLOG(1) << ENDPOINT << "Closing stream: " << id();
400    session_->CloseStream(id());
401  }
402}
403
404bool ReliableQuicStream::HasBufferedData() const {
405  return !queued_data_.empty();
406}
407
408void ReliableQuicStream::OnClose() {
409  CloseReadSide();
410  CloseWriteSide();
411
412  if (!fin_sent_ && !rst_sent_) {
413    // For flow control accounting, we must tell the peer how many bytes we have
414    // written on this stream before termination. Done here if needed, using a
415    // RST frame.
416    DVLOG(1) << ENDPOINT << "Sending RST in OnClose: " << id();
417    session_->SendRstStream(id(), QUIC_RST_FLOW_CONTROL_ACCOUNTING,
418                            stream_bytes_written_);
419    rst_sent_ = true;
420  }
421
422  // We are closing the stream and will not process any further incoming bytes.
423  // As there may be more bytes in flight and we need to ensure that both
424  // endpoints have the same connection level flow control state, mark all
425  // unreceived or buffered bytes as consumed.
426  uint64 bytes_to_consume = flow_controller_.highest_received_byte_offset() -
427      flow_controller_.bytes_consumed();
428  AddBytesConsumed(bytes_to_consume);
429}
430
431void ReliableQuicStream::OnWindowUpdateFrame(
432    const QuicWindowUpdateFrame& frame) {
433  if (!flow_controller_.IsEnabled()) {
434    DLOG(DFATAL) << "Flow control not enabled! " << version();
435    return;
436  }
437
438  if (flow_controller_.UpdateSendWindowOffset(frame.byte_offset)) {
439    // We can write again!
440    // TODO(rjshade): This does not respect priorities (e.g. multiple
441    //                outstanding POSTs are unblocked on arrival of
442    //                SHLO with initial window).
443    // As long as the connection is not flow control blocked, we can write!
444    OnCanWrite();
445  }
446}
447
448bool ReliableQuicStream::MaybeIncreaseHighestReceivedOffset(uint64 new_offset) {
449  if (flow_controller_.IsEnabled()) {
450    uint64 increment =
451        new_offset - flow_controller_.highest_received_byte_offset();
452    if (flow_controller_.UpdateHighestReceivedOffset(new_offset)) {
453      // If |new_offset| increased the stream flow controller's highest received
454      // offset, then we need to increase the connection flow controller's value
455      // by the incremental difference.
456      connection_flow_controller_->UpdateHighestReceivedOffset(
457          connection_flow_controller_->highest_received_byte_offset() +
458          increment);
459      return true;
460    }
461  }
462  return false;
463}
464
465void ReliableQuicStream::AddBytesSent(uint64 bytes) {
466  if (flow_controller_.IsEnabled()) {
467    flow_controller_.AddBytesSent(bytes);
468    connection_flow_controller_->AddBytesSent(bytes);
469  }
470}
471
472void ReliableQuicStream::AddBytesConsumed(uint64 bytes) {
473  if (flow_controller_.IsEnabled()) {
474    // Only adjust stream level flow controller if we are still reading.
475    if (!read_side_closed_) {
476      flow_controller_.AddBytesConsumed(bytes);
477    }
478
479    connection_flow_controller_->AddBytesConsumed(bytes);
480  }
481}
482
483bool ReliableQuicStream::IsFlowControlBlocked() {
484  return flow_controller_.IsBlocked() ||
485         connection_flow_controller_->IsBlocked();
486}
487
488}  // namespace net
489