forked from chromium/chromium
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathquic_connection.cc
1581 lines (1396 loc) · 57.5 KB
/
quic_connection.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/quic/quic_connection.h"
#include <algorithm>
#include "base/logging.h"
#include "base/stl_util.h"
#include "net/quic/crypto/quic_decrypter.h"
#include "net/quic/crypto/quic_encrypter.h"
#include "net/quic/quic_utils.h"
using base::hash_map;
using base::hash_set;
using base::StringPiece;
using std::list;
using std::make_pair;
using std::min;
using std::max;
using std::vector;
using std::set;
using std::string;
namespace net {
namespace {
// The largest gap in packets we'll accept without closing the connection.
// This will likely have to be tuned.
const QuicPacketSequenceNumber kMaxPacketGap = 5000;
// We want to make sure if we get a large nack packet, we don't queue up too
// many packets at once. 10 is arbitrary.
const int kMaxRetransmissionsPerAck = 10;
// TCP retransmits after 2 nacks. We allow for a third in case of out-of-order
// delivery.
// TODO(ianswett): Change to match TCP's rule of retransmitting once an ack
// at least 3 sequence numbers larger arrives.
const size_t kNumberOfNacksBeforeRetransmission = 3;
// The maxiumum number of packets we'd like to queue. We may end up queueing
// more in the case of many control frames.
// 6 is arbitrary.
const int kMaxPacketsToSerializeAtOnce = 6;
// Limit the number of packets we send per retransmission-alarm so we
// eventually cede. 10 is arbitrary.
const size_t kMaxPacketsPerRetransmissionAlarm = 10;
// Limit the number of FEC groups to two. If we get enough out of order packets
// that this becomes limiting, we can revisit.
const size_t kMaxFecGroups = 2;
// Limit the number of undecryptable packets we buffer in
// expectation of the CHLO/SHLO arriving.
const size_t kMaxUndecryptablePackets = 10;
bool Near(QuicPacketSequenceNumber a, QuicPacketSequenceNumber b) {
QuicPacketSequenceNumber delta = (a > b) ? a - b : b - a;
return delta <= kMaxPacketGap;
}
} // namespace
#define ENDPOINT (is_server_ ? "Server: " : " Client: ")
QuicConnection::QuicConnection(QuicGuid guid,
IPEndPoint address,
QuicConnectionHelperInterface* helper,
bool is_server,
QuicVersion version)
: framer_(version,
helper->GetClock()->ApproximateNow(),
is_server),
helper_(helper),
encryption_level_(ENCRYPTION_NONE),
clock_(helper->GetClock()),
random_generator_(helper->GetRandomGenerator()),
guid_(guid),
peer_address_(address),
largest_seen_packet_with_ack_(0),
peer_largest_observed_packet_(0),
least_packet_awaited_by_peer_(1),
peer_least_packet_awaiting_ack_(0),
handling_retransmission_timeout_(false),
write_blocked_(false),
debug_visitor_(NULL),
packet_creator_(guid_, &framer_, random_generator_, is_server),
packet_generator_(this, NULL, &packet_creator_),
idle_network_timeout_(
QuicTime::Delta::FromSeconds(kDefaultInitialTimeoutSecs)),
overall_connection_timeout_(QuicTime::Delta::Infinite()),
creation_time_(clock_->ApproximateNow()),
time_of_last_received_packet_(clock_->ApproximateNow()),
time_of_last_sent_packet_(clock_->ApproximateNow()),
time_largest_observed_(QuicTime::Zero()),
congestion_manager_(clock_, kTCP),
version_negotiation_state_(START_NEGOTIATION),
max_packets_per_retransmission_alarm_(kMaxPacketsPerRetransmissionAlarm),
is_server_(is_server),
connected_(true),
received_truncated_ack_(false),
send_ack_in_response_to_packet_(false),
address_migrating_(false) {
helper_->SetConnection(this);
helper_->SetTimeoutAlarm(idle_network_timeout_);
framer_.set_visitor(this);
framer_.set_received_entropy_calculator(&received_entropy_manager_);
outgoing_ack_.sent_info.least_unacked = 0;
outgoing_ack_.sent_info.entropy_hash = 0;
outgoing_ack_.received_info.largest_observed = 0;
outgoing_ack_.received_info.entropy_hash = 0;
/*
if (FLAGS_fake_packet_loss_percentage > 0) {
int32 seed = RandomBase::WeakSeed32();
LOG(INFO) << ENDPOINT << "Seeding packet loss with " << seed;
random_.reset(new MTRandom(seed));
}
*/
}
QuicConnection::~QuicConnection() {
STLDeleteElements(&undecryptable_packets_);
STLDeleteValues(&unacked_packets_);
STLDeleteValues(&group_map_);
for (QueuedPacketList::iterator it = queued_packets_.begin();
it != queued_packets_.end(); ++it) {
delete it->packet;
}
DLOG(INFO) << ENDPOINT << "write_blocked: " << write_blocked_;
}
bool QuicConnection::SelectMutualVersion(
const QuicVersionVector& available_versions) {
// Try to find the highest mutual version by iterating over supported
// versions, starting with the highest, and breaking out of the loop once we
// find a matching version in the provided available_versions vector.
for (size_t i = 0; i < arraysize(kSupportedQuicVersions); ++i) {
const QuicVersion& version = kSupportedQuicVersions[i];
if (std::find(available_versions.begin(), available_versions.end(),
version) != available_versions.end()) {
framer_.set_version(version);
return true;
}
}
return false;
}
void QuicConnection::OnError(QuicFramer* framer) {
// Packets that we cannot decrypt are dropped.
// TODO(rch): add stats to measure this.
if (!connected_ || framer->error() == QUIC_DECRYPTION_FAILURE) {
return;
}
SendConnectionClose(framer->error());
}
void QuicConnection::OnPacket() {
}
void QuicConnection::OnPublicResetPacket(
const QuicPublicResetPacket& packet) {
if (debug_visitor_) {
debug_visitor_->OnPublicResetPacket(packet);
}
CloseConnection(QUIC_PUBLIC_RESET, true);
}
bool QuicConnection::OnProtocolVersionMismatch(QuicVersion received_version) {
// TODO(satyamshekhar): Implement no server state in this mode.
if (!is_server_) {
LOG(DFATAL) << ENDPOINT << "Framer called OnProtocolVersionMismatch. "
<< "Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return false;
}
DCHECK_NE(version(), received_version);
if (debug_visitor_) {
debug_visitor_->OnProtocolVersionMismatch(received_version);
}
switch (version_negotiation_state_) {
case START_NEGOTIATION:
if (!framer_.IsSupportedVersion(received_version)) {
SendVersionNegotiationPacket();
version_negotiation_state_ = SENT_NEGOTIATION_PACKET;
return false;
}
break;
case SENT_NEGOTIATION_PACKET:
if (!framer_.IsSupportedVersion(received_version)) {
// Drop packets which can't be parsed due to version mismatch.
return false;
}
break;
case NEGOTIATED_VERSION:
// Might be old packets that were sent by the client before the version
// was negotiated. Drop these.
return false;
default:
DCHECK(false);
}
version_negotiation_state_ = NEGOTIATED_VERSION;
// Store the new version.
framer_.set_version(received_version);
// TODO(satyamshekhar): Store the sequence number of this packet and close the
// connection if we ever received a packet with incorrect version and whose
// sequence number is greater.
return true;
}
// Handles version negotiation for client connection.
void QuicConnection::OnVersionNegotiationPacket(
const QuicVersionNegotiationPacket& packet) {
if (is_server_) {
LOG(DFATAL) << ENDPOINT << "Framer parsed VersionNegotiationPacket."
<< " Closing connection.";
CloseConnection(QUIC_INTERNAL_ERROR, false);
return;
}
if (debug_visitor_) {
debug_visitor_->OnVersionNegotiationPacket(packet);
}
if (version_negotiation_state_ == NEGOTIATED_VERSION) {
// Possibly a duplicate version negotiation packet.
return;
}
if (std::find(packet.versions.begin(),
packet.versions.end(), version()) !=
packet.versions.end()) {
DLOG(WARNING) << ENDPOINT << "The server already supports our version. "
<< "It should have accepted our connection.";
// Just drop the connection.
CloseConnection(QUIC_INVALID_VERSION_NEGOTIATION_PACKET, false);
return;
}
if (!SelectMutualVersion(packet.versions)) {
SendConnectionCloseWithDetails(QUIC_INVALID_VERSION,
"no common version found");
return;
}
version_negotiation_state_ = NEGOTIATED_VERSION;
RetransmitUnackedPackets(ALL_PACKETS);
}
void QuicConnection::OnRevivedPacket() {
}
bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
if (debug_visitor_) {
debug_visitor_->OnPacketHeader(header);
}
if (!ProcessValidatedPacket()) {
return false;
}
// Will be decrement below if we fall through to return true;
++stats_.packets_dropped;
if (header.public_header.guid != guid_) {
DLOG(INFO) << ENDPOINT << "Ignoring packet from unexpected GUID: "
<< header.public_header.guid << " instead of " << guid_;
return false;
}
if (!Near(header.packet_sequence_number,
last_header_.packet_sequence_number)) {
DLOG(INFO) << ENDPOINT << "Packet " << header.packet_sequence_number
<< " out of bounds. Discarding";
SendConnectionCloseWithDetails(QUIC_INVALID_PACKET_HEADER,
"Packet sequence number out of bounds");
return false;
}
// If this packet has already been seen, or that the sender
// has told us will not be retransmitted, then stop processing the packet.
if (!IsAwaitingPacket(outgoing_ack_.received_info,
header.packet_sequence_number)) {
return false;
}
if (version_negotiation_state_ != NEGOTIATED_VERSION) {
if (is_server_) {
if (!header.public_header.version_flag) {
DLOG(WARNING) << ENDPOINT << "Got packet without version flag before "
<< "version negotiated.";
// Packets should have the version flag till version negotiation is
// done.
CloseConnection(QUIC_INVALID_VERSION, false);
return false;
} else {
DCHECK_EQ(1u, header.public_header.versions.size());
DCHECK_EQ(header.public_header.versions[0], version());
version_negotiation_state_ = NEGOTIATED_VERSION;
}
} else {
DCHECK(!header.public_header.version_flag);
// If the client gets a packet without the version flag from the server
// it should stop sending version since the version negotiation is done.
packet_creator_.StopSendingVersion();
version_negotiation_state_ = NEGOTIATED_VERSION;
}
}
DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
--stats_.packets_dropped;
DVLOG(1) << ENDPOINT << "Received packet header: " << header;
last_header_ = header;
return true;
}
void QuicConnection::OnFecProtectedPayload(StringPiece payload) {
DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
DCHECK_NE(0u, last_header_.fec_group);
QuicFecGroup* group = GetFecGroup();
if (group != NULL) {
group->Update(last_header_, payload);
}
}
bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnStreamFrame(frame);
}
last_stream_frames_.push_back(frame);
return true;
}
bool QuicConnection::OnAckFrame(const QuicAckFrame& incoming_ack) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnAckFrame(incoming_ack);
}
DVLOG(1) << ENDPOINT << "OnAckFrame: " << incoming_ack;
if (last_header_.packet_sequence_number <= largest_seen_packet_with_ack_) {
DLOG(INFO) << ENDPOINT << "Received an old ack frame: ignoring";
return true;
}
largest_seen_packet_with_ack_ = last_header_.packet_sequence_number;
if (!ValidateAckFrame(incoming_ack)) {
SendConnectionClose(QUIC_INVALID_ACK_DATA);
return false;
}
received_truncated_ack_ =
incoming_ack.received_info.missing_packets.size() >=
QuicFramer::GetMaxUnackedPackets(last_header_);
UpdatePacketInformationReceivedByPeer(incoming_ack);
UpdatePacketInformationSentByPeer(incoming_ack);
congestion_manager_.OnIncomingAckFrame(incoming_ack,
time_of_last_received_packet_);
// Now the we have received an ack, we might be able to send packets which are
// queued locally, or drain streams which are blocked.
QuicTime::Delta delay = congestion_manager_.TimeUntilSend(
time_of_last_received_packet_, NOT_RETRANSMISSION,
HAS_RETRANSMITTABLE_DATA);
if (delay.IsZero()) {
helper_->UnregisterSendAlarmIfRegistered();
if (!write_blocked_) {
OnCanWrite();
}
} else if (!delay.IsInfinite()) {
helper_->SetSendAlarm(time_of_last_received_packet_.Add(delay));
}
return connected_;
}
bool QuicConnection::OnCongestionFeedbackFrame(
const QuicCongestionFeedbackFrame& feedback) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnCongestionFeedbackFrame(feedback);
}
congestion_manager_.OnIncomingQuicCongestionFeedbackFrame(
feedback, time_of_last_received_packet_);
return connected_;
}
bool QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
if (incoming_ack.received_info.largest_observed >
packet_creator_.sequence_number()) {
DLOG(ERROR) << ENDPOINT << "Peer's observed unsent packet:"
<< incoming_ack.received_info.largest_observed << " vs "
<< packet_creator_.sequence_number();
// We got an error for data we have not sent. Error out.
return false;
}
if (incoming_ack.received_info.largest_observed <
peer_largest_observed_packet_) {
DLOG(ERROR) << ENDPOINT << "Peer's largest_observed packet decreased:"
<< incoming_ack.received_info.largest_observed << " vs "
<< peer_largest_observed_packet_;
// A new ack has a diminished largest_observed value. Error out.
// If this was an old packet, we wouldn't even have checked.
return false;
}
// We can't have too many unacked packets, or our ack frames go over
// kMaxPacketSize.
DCHECK_LE(incoming_ack.received_info.missing_packets.size(),
QuicFramer::GetMaxUnackedPackets(last_header_));
if (incoming_ack.sent_info.least_unacked < peer_least_packet_awaiting_ack_) {
DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
<< incoming_ack.sent_info.least_unacked
<< " vs " << peer_least_packet_awaiting_ack_;
// We never process old ack frames, so this number should only increase.
return false;
}
if (incoming_ack.sent_info.least_unacked >
last_header_.packet_sequence_number) {
DLOG(ERROR) << ENDPOINT << "Peer sent least_unacked:"
<< incoming_ack.sent_info.least_unacked
<< " greater than the enclosing packet sequence number:"
<< last_header_.packet_sequence_number;
return false;
}
if (!incoming_ack.received_info.missing_packets.empty() &&
*incoming_ack.received_info.missing_packets.rbegin() >
incoming_ack.received_info.largest_observed) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.received_info.missing_packets.rbegin()
<< " greater than largest observed: "
<< incoming_ack.received_info.largest_observed;
return false;
}
if (!incoming_ack.received_info.missing_packets.empty() &&
*incoming_ack.received_info.missing_packets.begin() <
least_packet_awaited_by_peer_) {
DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
<< *incoming_ack.received_info.missing_packets.begin()
<< "smaller than least_packet_awaited_by_peer_: "
<< least_packet_awaited_by_peer_;
return false;
}
if (!sent_entropy_manager_.IsValidEntropy(
incoming_ack.received_info.largest_observed,
incoming_ack.received_info.missing_packets,
incoming_ack.received_info.entropy_hash)) {
DLOG(ERROR) << ENDPOINT << "Peer sent invalid entropy.";
return false;
}
return true;
}
void QuicConnection::HandleAckForSentPackets(const QuicAckFrame& incoming_ack,
SequenceNumberSet* acked_packets) {
int retransmitted_packets = 0;
// Go through the packets we have not received an ack for and see if this
// incoming_ack shows they've been seen by the peer.
UnackedPacketMap::iterator it = unacked_packets_.begin();
while (it != unacked_packets_.end()) {
QuicPacketSequenceNumber sequence_number = it->first;
if (sequence_number > peer_largest_observed_packet_) {
// These are very new sequence_numbers.
break;
}
RetransmittableFrames* unacked = it->second;
if (!IsAwaitingPacket(incoming_ack.received_info, sequence_number)) {
// Packet was acked, so remove it from our unacked packet list.
DVLOG(1) << ENDPOINT <<"Got an ack for packet " << sequence_number;
acked_packets->insert(sequence_number);
delete unacked;
unacked_packets_.erase(it++);
retransmission_map_.erase(sequence_number);
} else {
// This is a packet which we planned on retransmitting and has not been
// seen at the time of this ack being sent out. See if it's our new
// lowest unacked packet.
DVLOG(1) << ENDPOINT << "still missing packet " << sequence_number;
++it;
// The peer got packets after this sequence number. This is an explicit
// nack.
RetransmissionMap::iterator retransmission_it =
retransmission_map_.find(sequence_number);
++(retransmission_it->second.number_nacks);
if (retransmission_it->second.number_nacks >=
kNumberOfNacksBeforeRetransmission &&
retransmitted_packets < kMaxRetransmissionsPerAck) {
++retransmitted_packets;
DVLOG(1) << ENDPOINT << "Trying to retransmit packet "
<< sequence_number
<< " as it has been nacked 3 or more times.";
// RetransmitPacket will retransmit with a new sequence_number.
RetransmitPacket(sequence_number);
}
}
}
}
void QuicConnection::HandleAckForSentFecPackets(
const QuicAckFrame& incoming_ack, SequenceNumberSet* acked_packets) {
UnackedPacketMap::iterator it = unacked_fec_packets_.begin();
while (it != unacked_fec_packets_.end()) {
QuicPacketSequenceNumber sequence_number = it->first;
if (sequence_number > peer_largest_observed_packet_) {
break;
}
if (!IsAwaitingPacket(incoming_ack.received_info, sequence_number)) {
DVLOG(1) << ENDPOINT << "Got an ack for fec packet: " << sequence_number;
acked_packets->insert(sequence_number);
unacked_fec_packets_.erase(it++);
} else {
DVLOG(1) << ENDPOINT << "Still missing ack for fec packet: "
<< sequence_number;
++it;
}
}
}
void QuicConnection::UpdatePacketInformationReceivedByPeer(
const QuicAckFrame& incoming_ack) {
// ValidateAck should fail if largest_observed ever shrinks.
DCHECK_LE(peer_largest_observed_packet_,
incoming_ack.received_info.largest_observed);
peer_largest_observed_packet_ = incoming_ack.received_info.largest_observed;
if (incoming_ack.received_info.missing_packets.empty()) {
least_packet_awaited_by_peer_ = peer_largest_observed_packet_ + 1;
} else {
least_packet_awaited_by_peer_ =
*(incoming_ack.received_info.missing_packets.begin());
}
sent_entropy_manager_.ClearEntropyBefore(least_packet_awaited_by_peer_ - 1);
SequenceNumberSet acked_packets;
HandleAckForSentPackets(incoming_ack, &acked_packets);
HandleAckForSentFecPackets(incoming_ack, &acked_packets);
if (acked_packets.size() > 0) {
visitor_->OnAck(acked_packets);
}
}
bool QuicConnection::DontWaitForPacketsBefore(
QuicPacketSequenceNumber least_unacked) {
size_t missing_packets_count =
outgoing_ack_.received_info.missing_packets.size();
outgoing_ack_.received_info.missing_packets.erase(
outgoing_ack_.received_info.missing_packets.begin(),
outgoing_ack_.received_info.missing_packets.lower_bound(least_unacked));
return missing_packets_count !=
outgoing_ack_.received_info.missing_packets.size();
}
void QuicConnection::UpdatePacketInformationSentByPeer(
const QuicAckFrame& incoming_ack) {
// ValidateAck() should fail if peer_least_packet_awaiting_ack_ shrinks.
DCHECK_LE(peer_least_packet_awaiting_ack_,
incoming_ack.sent_info.least_unacked);
if (incoming_ack.sent_info.least_unacked > peer_least_packet_awaiting_ack_) {
bool missed_packets =
DontWaitForPacketsBefore(incoming_ack.sent_info.least_unacked);
if (missed_packets || incoming_ack.sent_info.least_unacked >
outgoing_ack_.received_info.largest_observed + 1) {
DVLOG(1) << ENDPOINT << "Updating entropy hashed since we missed packets";
// There were some missing packets that we won't ever get now. Recalculate
// the received entropy hash.
received_entropy_manager_.RecalculateEntropyHash(
incoming_ack.sent_info.least_unacked,
incoming_ack.sent_info.entropy_hash);
}
peer_least_packet_awaiting_ack_ = incoming_ack.sent_info.least_unacked;
}
DCHECK(outgoing_ack_.received_info.missing_packets.empty() ||
*outgoing_ack_.received_info.missing_packets.begin() >=
peer_least_packet_awaiting_ack_);
// Possibly close any FecGroups which are now irrelevant
CloseFecGroupsBefore(incoming_ack.sent_info.least_unacked + 1);
}
void QuicConnection::OnFecData(const QuicFecData& fec) {
DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
DCHECK_NE(0u, last_header_.fec_group);
QuicFecGroup* group = GetFecGroup();
if (group != NULL) {
group->UpdateFec(last_header_.packet_sequence_number,
last_header_.entropy_flag, fec);
}
}
bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnRstStreamFrame(frame);
}
DLOG(INFO) << ENDPOINT << "Stream reset with error "
<< QuicUtils::StreamErrorToString(frame.error_code);
visitor_->OnRstStream(frame);
return connected_;
}
bool QuicConnection::OnConnectionCloseFrame(
const QuicConnectionCloseFrame& frame) {
DCHECK(connected_);
if (debug_visitor_) {
debug_visitor_->OnConnectionCloseFrame(frame);
}
DLOG(INFO) << ENDPOINT << "Connection closed with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " " << frame.error_details;
CloseConnection(frame.error_code, true);
return false;
}
bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
DCHECK(connected_);
DLOG(INFO) << ENDPOINT << "Go away received with error "
<< QuicUtils::ErrorToString(frame.error_code)
<< " and reason:" << frame.reason_phrase;
visitor_->OnGoAway(frame);
return connected_;
}
void QuicConnection::OnPacketComplete() {
// Don't do anything if this packet closed the connection.
if (!connected_) {
last_stream_frames_.clear();
return;
}
if (!last_packet_revived_) {
DLOG(INFO) << ENDPOINT << "Got packet "
<< last_header_.packet_sequence_number
<< " with " << last_stream_frames_.size()
<< " stream frames for " << last_header_.public_header.guid;
congestion_manager_.RecordIncomingPacket(
last_size_, last_header_.packet_sequence_number,
time_of_last_received_packet_, last_packet_revived_);
} else {
DLOG(INFO) << ENDPOINT << "Got revived packet with "
<< last_stream_frames_.size() << " frames.";
}
if ((last_stream_frames_.empty() ||
visitor_->OnPacket(self_address_, peer_address_,
last_header_, last_stream_frames_))) {
RecordPacketReceived(last_header_);
}
MaybeSendAckInResponseToPacket();
last_stream_frames_.clear();
}
QuicAckFrame* QuicConnection::CreateAckFrame() {
UpdateOutgoingAck();
if (time_largest_observed_ == QuicTime::Zero()) {
// We have not received any new higher sequence numbers since we sent our
// last ACK.
outgoing_ack_.received_info.delta_time_largest_observed =
QuicTime::Delta::Infinite();
} else {
outgoing_ack_.received_info.delta_time_largest_observed =
clock_->ApproximateNow().Subtract(time_largest_observed_);
time_largest_observed_ = QuicTime::Zero();
}
return new QuicAckFrame(outgoing_ack_);
}
QuicCongestionFeedbackFrame* QuicConnection::CreateFeedbackFrame() {
return new QuicCongestionFeedbackFrame(outgoing_congestion_feedback_);
}
void QuicConnection::MaybeSendAckInResponseToPacket() {
if (send_ack_in_response_to_packet_) {
SendAck();
} else if (!last_stream_frames_.empty()) {
// TODO(alyssar) this case should really be "if the packet contained any
// non-ack frame", rather than "if the packet contained a stream frame"
helper_->SetAckAlarm(congestion_manager_.DefaultRetransmissionTime());
}
send_ack_in_response_to_packet_ = !send_ack_in_response_to_packet_;
}
void QuicConnection::SendVersionNegotiationPacket() {
QuicVersionVector supported_versions;
for (size_t i = 0; i < arraysize(kSupportedQuicVersions); ++i) {
supported_versions.push_back(kSupportedQuicVersions[i]);
}
QuicEncryptedPacket* encrypted =
packet_creator_.SerializeVersionNegotiationPacket(supported_versions);
// TODO(satyamshekhar): implement zero server state negotiation.
int error;
helper_->WritePacketToWire(*encrypted, &error);
delete encrypted;
}
QuicConsumedData QuicConnection::SendStreamData(QuicStreamId id,
base::StringPiece data,
QuicStreamOffset offset,
bool fin) {
return packet_generator_.ConsumeData(id, data, offset, fin);
}
void QuicConnection::SendRstStream(QuicStreamId id,
QuicRstStreamErrorCode error) {
packet_generator_.AddControlFrame(
QuicFrame(new QuicRstStreamFrame(id, error)));
}
const QuicConnectionStats& QuicConnection::GetStats() {
// Update rtt and estimated bandwidth.
stats_.rtt = congestion_manager_.SmoothedRtt().ToMicroseconds();
stats_.estimated_bandwidth =
congestion_manager_.BandwidthEstimate().ToBytesPerSecond();
return stats_;
}
void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
const IPEndPoint& peer_address,
const QuicEncryptedPacket& packet) {
if (!connected_) {
return;
}
if (debug_visitor_) {
debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
}
last_packet_revived_ = false;
last_size_ = packet.length();
address_migrating_ = false;
if (peer_address_.address().empty()) {
peer_address_ = peer_address;
}
if (self_address_.address().empty()) {
self_address_ = self_address;
}
if (!(peer_address == peer_address_ && self_address == self_address_)) {
address_migrating_ = true;
}
stats_.bytes_received += packet.length();
++stats_.packets_received;
if (!framer_.ProcessPacket(packet)) {
// If we are unable to decrypt this packet, it might be
// because the CHLO or SHLO packet was lost.
if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
framer_.error() == QUIC_DECRYPTION_FAILURE &&
undecryptable_packets_.size() < kMaxUndecryptablePackets) {
QueueUndecryptablePacket(packet);
}
DVLOG(1) << ENDPOINT << "Unable to process packet. Last packet processed: "
<< last_header_.packet_sequence_number;
return;
}
MaybeProcessUndecryptablePackets();
MaybeProcessRevivedPacket();
}
bool QuicConnection::OnCanWrite() {
write_blocked_ = false;
WriteQueuedPackets();
// Sending queued packets may have caused the socket to become write blocked,
// or the congestion manager to prohibit sending. If we've sent everything
// we had queued and we're still not blocked, let the visitor know it can
// write more.
if (CanWrite(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA)) {
packet_generator_.StartBatchOperations();
bool all_bytes_written = visitor_->OnCanWrite();
packet_generator_.FinishBatchOperations();
// After the visitor writes, it may have caused the socket to become write
// blocked or the congestion manager to prohibit sending, so check again.
if (!write_blocked_ && !all_bytes_written &&
CanWrite(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA)) {
// We're not write blocked, but some stream didn't write out all of its
// bytes. Register for 'immediate' resumption so we'll keep writing after
// other quic connections have had a chance to use the socket.
helper_->SetSendAlarm(clock_->ApproximateNow());
}
}
return !write_blocked_;
}
bool QuicConnection::ProcessValidatedPacket() {
if (address_migrating_) {
SendConnectionCloseWithDetails(
QUIC_ERROR_MIGRATING_ADDRESS,
"Address migration is not yet a supported feature");
return false;
}
time_of_last_received_packet_ = clock_->Now();
DVLOG(1) << ENDPOINT << "time of last received packet: "
<< time_of_last_received_packet_.ToDebuggingValue();
return true;
}
bool QuicConnection::WriteQueuedPackets() {
DCHECK(!write_blocked_);
size_t num_queued_packets = queued_packets_.size() + 1;
QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
while (!write_blocked_ && packet_iterator != queued_packets_.end()) {
// Ensure that from one iteration of this loop to the next we
// succeeded in sending a packet so we don't infinitely loop.
// TODO(rch): clean up and close the connection if we really hit this.
DCHECK_LT(queued_packets_.size(), num_queued_packets);
num_queued_packets = queued_packets_.size();
if (WritePacket(packet_iterator->encryption_level,
packet_iterator->sequence_number,
packet_iterator->packet,
packet_iterator->retransmittable,
NO_FORCE)) {
packet_iterator = queued_packets_.erase(packet_iterator);
} else {
// Continue, because some queued packets may still be writable.
// This can happen if a retransmit send fail.
++packet_iterator;
}
}
return !write_blocked_;
}
void QuicConnection::RecordPacketReceived(const QuicPacketHeader& header) {
QuicPacketSequenceNumber sequence_number = header.packet_sequence_number;
DCHECK(IsAwaitingPacket(outgoing_ack_.received_info, sequence_number));
InsertMissingPacketsBetween(
&outgoing_ack_.received_info,
max(outgoing_ack_.received_info.largest_observed + 1,
peer_least_packet_awaiting_ack_),
header.packet_sequence_number);
if (outgoing_ack_.received_info.largest_observed >
header.packet_sequence_number) {
// We've gotten one of the out of order packets - remove it from our
// "missing packets" list.
DVLOG(1) << ENDPOINT << "Removing " << sequence_number
<< " from missing list";
outgoing_ack_.received_info.missing_packets.erase(sequence_number);
}
if (header.packet_sequence_number >
outgoing_ack_.received_info.largest_observed) {
outgoing_ack_.received_info.largest_observed =
header.packet_sequence_number;
time_largest_observed_ = time_of_last_received_packet_;
}
received_entropy_manager_.RecordPacketEntropyHash(
sequence_number, header.entropy_hash);
}
bool QuicConnection::MaybeRetransmitPacketForRTO(
QuicPacketSequenceNumber sequence_number) {
DCHECK_EQ(ContainsKey(unacked_packets_, sequence_number),
ContainsKey(retransmission_map_, sequence_number));
if (!ContainsKey(unacked_packets_, sequence_number)) {
DVLOG(2) << ENDPOINT << "alarm fired for " << sequence_number
<< " but it has been acked or already retransmitted with"
<< " different sequence number.";
// So no extra delay is added for this packet.
return true;
}
RetransmissionMap::iterator retransmission_it =
retransmission_map_.find(sequence_number);
// If the packet hasn't been acked and we're getting truncated acks, ignore
// any RTO for packets larger than the peer's largest observed packet; it may
// have been received by the peer and just wasn't acked due to the ack frame
// running out of space.
if (received_truncated_ack_ &&
sequence_number > peer_largest_observed_packet_ &&
// We allow retransmission of already retransmitted packets so that we
// retransmit packets that were retransmissions of the packet with
// sequence number < the largest observed field of the truncated ack.
retransmission_it->second.number_retransmissions == 0) {
return false;
} else {
++stats_.rto_count;
RetransmitPacket(sequence_number);
return true;
}
}
void QuicConnection::RetransmitUnackedPackets(
RetransmissionType retransmission_type) {
if (unacked_packets_.empty()) {
return;
}
UnackedPacketMap::iterator next_it = unacked_packets_.begin();
QuicPacketSequenceNumber end_sequence_number =
unacked_packets_.rbegin()->first;
do {
UnackedPacketMap::iterator current_it = next_it;
++next_it;
if (retransmission_type == ALL_PACKETS ||
current_it->second->encryption_level() == ENCRYPTION_INITIAL) {
// TODO(satyamshekhar): Think about congestion control here.
// Specifically, about the retransmission count of packets being sent
// proactively to achieve 0 (minimal) RTT.
RetransmitPacket(current_it->first);
}
} while (next_it != unacked_packets_.end() &&
next_it->first <= end_sequence_number);
}
void QuicConnection::RetransmitPacket(
QuicPacketSequenceNumber sequence_number) {
UnackedPacketMap::iterator unacked_it =
unacked_packets_.find(sequence_number);
RetransmissionMap::iterator retransmission_it =
retransmission_map_.find(sequence_number);
// There should always be an entry corresponding to |sequence_number| in
// both |retransmission_map_| and |unacked_packets_|. Retransmissions due to
// RTO for sequence numbers that are already acked or retransmitted are
// ignored by MaybeRetransmitPacketForRTO.
DCHECK(unacked_it != unacked_packets_.end());
DCHECK(retransmission_it != retransmission_map_.end());
RetransmittableFrames* unacked = unacked_it->second;
// TODO(pwestin): Need to fix potential issue with FEC and a 1 packet
// congestion window see b/8331807 for details.
congestion_manager_.AbandoningPacket(sequence_number);
// Re-packetize the frames with a new sequence number for retransmission.
// Retransmitted data packets do not use FEC, even when it's enabled.
SerializedPacket serialized_packet =
packet_creator_.SerializeAllFrames(unacked->frames());
RetransmissionInfo retransmission_info(serialized_packet.sequence_number);
retransmission_info.number_retransmissions =
retransmission_it->second.number_retransmissions + 1;
retransmission_map_.insert(make_pair(serialized_packet.sequence_number,
retransmission_info));
// Remove info with old sequence number.
unacked_packets_.erase(unacked_it);
retransmission_map_.erase(retransmission_it);
DVLOG(1) << ENDPOINT << "Retransmitting unacked packet " << sequence_number
<< " as " << serialized_packet.sequence_number;
DCHECK(unacked_packets_.empty() ||
unacked_packets_.rbegin()->first < serialized_packet.sequence_number);
unacked_packets_.insert(make_pair(serialized_packet.sequence_number,
unacked));
SendOrQueuePacket(unacked->encryption_level(),
serialized_packet.sequence_number,
serialized_packet.packet,
serialized_packet.entropy_hash,
HAS_RETRANSMITTABLE_DATA);
}
bool QuicConnection::CanWrite(Retransmission retransmission,
HasRetransmittableData retransmittable) {
// TODO(ianswett): If the packet is a retransmit, the current send alarm may
// be too long.
if (write_blocked_ || helper_->IsSendAlarmSet()) {
return false;
}
QuicTime now = clock_->Now();
QuicTime::Delta delay = congestion_manager_.TimeUntilSend(
now, retransmission, retransmittable);
if (delay.IsInfinite()) {
return false;
}
// If the scheduler requires a delay, then we can not send this packet now.
if (!delay.IsZero()) {
helper_->SetSendAlarm(now.Add(delay));
return false;
}
return true;
}
bool QuicConnection::IsRetransmission(