CHANGELOG revision 55613f44
12020-03-30
2    - 2.14.0
3    - [API] Use lsxpack_header structure to send HTTP headers.
4    - [OPTIMIZATION] nocopy's readable_bytes() function.
5    - http_server: fix typo in error message
6    - Use ls-hpack 2.1.0.
7    - Use ls-qpack 2.0.0.
8
92020-03-23
10    - 2.13.3
11    - [BUGFIX] ACK ping-pong: TIMESTAMP frame is not to be acked.
12
132020-03-13
14    - 2.13.2
15    - [BUGFIX] Use of new lsxpack_header API's hsi_prepare_decode().
16
172020-03-12
18    - 2.13.1
19    - [API] Use lsxpack_header structure to process incoming headers.
20    - [BUGFIX] Fix assertion when zero-padding Initial packet.
21    - [BUGFIX] Use idle timeout before we learn of peer's value.
22    - Use ls-hpack 2.0.1 -- has lsxpack_header changes.
23    - Use ls-qpack 0.14.0 -- new, common with ls-hpack, XXH seed (not
24      used yet).
25    - Code cleanup: prefix exported functions with "lsquic_".
26
272020-03-02
28    - 2.12.0
29    - [FEATURE] QUIC timestamps extension.
30    - [API] New: ea_alpn that is used when not in HTTP mode.
31    - [BUGFIX] SNI is mandatory only for HTTP/3 and gQUIC.
32    - [BUGFIX] Benign double-free -- issue #110.
33    - [BUGFIX] Printing of transport parameters.
34
352020-02-24
36    - 2.11.1
37    - [FEATURE] QUIC and HTTP/3 Internet Draft 27 support.
38    - [FEATURE] Add experimental delayed ACKs extension.
39    - Drop support for Internet Draft 24.
40    - Code cleanup.
41
422020-02-14
43    - 2.10.6
44    - [BUGFIX] HTTP/3 framing: don't misinterpret rare occurence as error.
45    - [BUGFIX] Send gap warning due to missing poisoned packet.
46    - Stream unit test for scenario in issue #106.
47
482020-02-13
49    - 2.10.5
50    - [BUGFIX] BBR: call cci_sent() with correct arguments and at correct
51      time.
52    - Refactor transport parameters module.
53    - Minor code cleanup.
54
552020-02-11
56    - 2.10.4
57    - [BUGFIX] Send HANDSHAKE_DONE only after Finished is received.
58    - [BUGFIX] Don't treat garbage UDP padding as library error; ignore
59      it instead.
60    - [BUGFIX] Fix compilation on FreeBSD (missing header).
61    - Code cleanup: remove unnecessary #includes.
62
632020-01-31
64    - 2.10.3
65    - [BUGFIX] Cancel path responses and challenges on old path when
66      switching to new path
67    - Logging network path information.
68
692020-01-30
70    - 2.10.2
71    - [BUGFIX] Do not delay ACKs for Initial and Handshake packets.
72    - [BUGFIX] Send PATH_CHALLENGE if path changed before mini conn
73      promotion.
74    - Logging improvements.
75    - http_client: discard data faster.
76
772020-01-29
78    - 2.10.1
79    - [BUGFIX] Coalesced packets could get longer than normal packet
80      size.
81    - Add spin bit configuration option es_spin (-o spin=[01]).
82    - Disable spin bit in 1/16 of connections.
83    - Improve logging a bit.
84
852020-01-28
86    - 2.10.0
87    - [FEATURE] QUIC and HTTP/3 Internet Draft 25 support.
88    - [API] Drop support for ID-23.
89    - [BUGFIX] Set key phase bit on outgoing packets correctly.
90    - Code cleanup.
91
922020-01-20
93    - 2.9.0
94    - [API] Drop support for Q039.
95    - Improve ACK-queuing logic.  Send an ACK once in a while if
96      peer keeps on sending non-ack-eliciting packets.
97    - Improve Alt-Svc string: Q050 and later are not included in
98      the old-style "quic" string.
99    - Send stateless resets if connection could not be promoted.
100    - Schedule MAX_DATA if needed when DATA_BLOCKED is received.
101    - Use ls-qpack 0.11.2 -- needed for server push optimization.
102    - Code cleanup: handle some error cases, improve logging.
103
1042020-01-16
105    - 2.8.9
106    - [BUGFIX] Use ls-qpack 0.11.1
107    - [OPTIMIZATION] Generate random bytes in batches.
108    - Change loss_bits transport parameter ID to 0x1057 following
109      latest draft.
110    - Randomize period with which PINGs are sent to elicit ACKs.
111    - Some refactoring and code cleanup.
112
1132020-01-14
114    - 2.8.8
115    - [BUGFIX] Invalid read when parsing IETF transport parameters
116      (this was benign).
117    - [OPTIMIZATION] Frame bundling when using buffered packets in
118      IETF QUIC: a) flush QPACK decoder stream and b) include ACKs
119      in opportunistic fashion.
120    - Fix HTTP/3 framing unit test.
121    - Code cleanup.
122
1232020-01-09
124    - 2.8.7
125    - [BUGFIX] Initial packet size check for IETF mini conn applies to
126      UDP payload, not QUIC packet.
127    - Support old and new school loss_bits transport parameter.
128    - Use Q run length of 64 as suggested in the loss bits Draft.
129    - Undo square wave count when packet is delayed.
130    - Code cleanup; minor fixes.
131
1322020-01-06
133    - 2.8.5
134    - [HTTP3] Verify number of bytes in incoming DATA frames against
135      content-length.
136    - [HTTP3] Stop issuing streams credits if peer stops opening QPACK
137      decoder window.  This addresses a potential attack whereby client
138      can cause the server to keep allocating memory.  See Security
139      Considerations in the QPACK draft.
140    - [BUGFIX] Mini conn: don't shorten max packet size for Q050 and later.
141    - [BUGFIX] Init IETF connection flow controller using correct setting.
142    - [BUGFIX] Fix unintended sign extension when removing header protection.
143    - Code cleanup and minor fixes.
144
1452019-12-30
146    - 2.8.1
147    - [FEATURE] Use occasional packet number gaps to detect optimistic
148      ACK attacks.
149    - [BUGFIX] Q050 client: all packet numbers are in the App PNS.
150    - [OPTIMIZATION] Merge multi-range ACK frames, not just single-range
151      ACK frames.
152    - IETF QUIC: use RTT estimate in ack timeout calculation.
153    - IETF handshake: abort conn when unexpected errors occur.
154    - Use PING rather than MAX_DATA frames to elicit ACKs from peer.
155    - Server: enforce 1200 byte Initial minimum packet size.
156    - [CLEANUP] Remove code to disable gQUIC crypto.
157    - [CLEANUP] Remove n_timestamps from ACK info struct.
158    - Optimize driver: reuse previous ancillary message when possible.
159
1602019-12-23
161    - 2.8.0
162    - [FEATURE] Add support for Q050.
163    - [OPTIMIZATION] Reduce mallocs in gQUIC handshake.
164    - [BUGFIX] Disable redo of failed STREAM frame insertion with debug
165      logging.
166
1672019-12-18
168    - 2.7.3
169    - [DEBUG] Further dedup next advisory tick messages when reason is
170      the same.
171    - [BUGFIX] Update size of `a` array in TP struct.  Fixes (benign)
172      GitHub bug #94.
173    - Use Cubic by default again instead of BBR, as it delivers more
174      consistent performance.
175
1762019-12-11
177    - 2.7.2
178    - [BUGFIX] Send controller: update scheduled bytes when DCID length
179      changes (IETF client).
180    - [BUGFIX] Drop alarm check from sanity test.  It no longer works now
181      that we use loss chains.
182    - [PORTABILITY] Fix build on Alpine Linux.
183    - [PORTABILITY] Fix build using XCode.
184    - Client initial DCID length: use RAND_bytes() instead of rand(3).
185    - Add unit tests for connection min heap.
186    - [DEBUG] Log CID in gQUIC handshake module
187    - [DEBUG] Turn on extra checks for IETF client send controller.
188    - [DEBUG] Dedup next advisory tick messages when reason is IDLE timer.
189    - [DEBUG] QPACK decoder handler: log header error code.
190
1912019-12-05
192    - 2.7.1
193    - [BUGFIX] client: don't call ignore_init() in middle of batch send.
194      ignore_init() makes an assumption that the send controller has access
195      to all outgoing packets.  This change wraps a few IETF full connection
196      methods to delay calling ignore_init() until the engine returns all
197      outgoing packets that were batched.
198    - [BUGFIX] set errno to EAGAIN if sendmmsg() can't send all of them.
199      This needs to be done because the value of errno may be lost on
200      some platforms.
201    - [BUGFIX] Typo that set all bits in sm_qflags lead to crashes.
202    - [BUGFIX] Do not cancel header block processing after failure, as
203      QPACK releases the reference in that case.
204    - [CLEANUP] IETF encrypt: replace assert(0) with a warning.
205    - Several small improvements to the test server.
206
2072019-11-27
208    - 2.7.0
209    - [API, FEATURE] Close connection immediately when ea_packets_out()
210      fails with errno != EAGAIN.  The API change is that errno is now
211      examined.  Make sure to set it if using something other than
212      sendmsg() to send packets.
213    - [CLEANUP] Immediate close logic in IETF full conn.
214    - [CLEANUP] Fix bogus warning about uninitialized `pair' variable.
215
2162019-11-22
217    - 2.6.7
218    - [FEATURE] Implement the QL extension (offered by default).
219    - [BUGFIX] Abort when encountering unexpected HTTP/3 frames.
220    - [BUGFIX] Acknowledge (QPACK) HTTP/3 trailers correctly.
221    - [DEBUG] Turn on debug message for next advisory tick.
222
2232019-11-20
224    - 2.6.6
225    - [BUGFIX] Using HTTP/3 to HTTP/1.x converter.
226    - [BUGFIX] Truncate log messages instead of throwing them away.
227
2282019-11-15
229    - 2.6.5
230    - [BUGFIX] High priority buffered packet queue length.
231    - [BUGFIX] Rain time calculation: max_ack_delay is in milliseconds.
232
2332019-11-12
234    - 2.6.3
235    - [BUGFIX] Close DATA frames with empty payload correctly.
236
2372019-11-11
238    - 2.6.2
239    - [BUGFIX] SCID!=ODCID rule applies to Retry packets, not regular
240      packets.
241    - [BUGFIX] Zero-RTT: BoringSSL no longer flips read/write secrets.
242    - [BUGFIX] Truncate ACK frame rather instead of aborting IETF
243      connection.
244    - [BUGFIX] Client: don't send duplicate reset tokens.
245    - [BUGFIX] Remove invalid assertion in H3 framing code.
246    - Silence a warning in send ctl by restructuring switch() statement.
247
2482019-11-08
249    - 2.6.1
250    - [BUGFIX] set retry token on all resubmitted packets.
251    - Event log: log sent packet flags.  In particular, this allows one
252      to see whether token was sent.
253    - Don't migrate client if es_allow_migration is false.
254
2552019-11-07
256    - 2.6.0
257    - [FEATURE] QUIC and HTTP/3 Internet Draft 24 support
258
2592019-11-07
260    - 2.5.2
261    - [BUGFIX] argument order to gQUIC client constructor.  Regression
262      introduced in 2.5.0.
263    - [BUGFIX] split buffered packet error recovery: destroy the correct
264      packet.
265
2662019-11-04
267    - 2.5.1
268    - [BUGFIX] Fix double-free when emptying a packet number space.
269    - [BUGFIX] http_server: fix md5sum handler: handle EOF correctly.
270    - [BUGFIX] Use random values in bits 4 and 5 of the first byte of
271      verneg packets (regression introduced in 2.5.0).
272    - [OPTIMIZATION] Don't compile in expensive attq checks by default.
273    - [OPTIMIZATION] http_server: compile regexes only once.
274
2752019-10-31
276    - 2.5.0
277    - [API] lsquic_engine_connect() can now be passed QUIC version to use.
278    - [OPTIMIZATION] Queue opportunistic ACKs if there is data to be sent.
279    - [BUGFIX] Don't evict streams from priority iterator if there is
280      only one queue.
281    - [OPTIMIZATION, BUGFIX] Several other optimizations and bug fixes.
282    - Use ls-qpack v0.10.7.
283
2842019-10-24
285    - 2.4.10
286    - [BUGFIX] IETF QUIC server: fix uninitialized variable use.
287    - [BUGFIX] make sure TLSv1.3 is not disabled in SSL object.
288    - [BUGFIX] Use issuer name and serial number to cache certs (SKID
289      values are not unique).
290    - [BUGFIX] Always set the idle alarm in IETF connection so that it
291      can time out.
292    - Use ls-qpack v0.10.6, as it silences some warnings.
293
2942019-10-21
295    - 2.4.8
296    - [OPTIMIZATION, BUGFIX] Use ls-qpack v0.10.5.
297
2982019-10-15
299    - 2.4.7
300    - Add echo client and server to the distibution.
301    - Add MD5 client and server to the distibution.
302    - Fix http_client: check command-line arguments better, prevent crash.
303    - Fix IETF conn: can_write_ack() should only care about APP PNS.
304    - Client: delay stream creation until handshake succeds.
305    - Reset HTTP stream whose write end is closed prematurely.
306    - Fix tickable(): mirror behavior of tick() wrt buffered packets.
307    - Log reason why engine is tickable.
308
3092019-10-11
310    - 2.4.6
311    - Minor code cleanup and logging improvements.
312    - Server and client programs: include library version (e.g. 2.4.6)
313      into `server' and `user-agent' headers.
314
3152019-10-08
316    - 2.4.5
317    - [OPTIMIZATION]: flush encoder stream only when necessary.
318    - [BUGFIX] Use ls-qpack v0.10.2 for new API -- and for a bug fix.
319    - [BUGFIX] Typo in IETF conn SETTINGS writer.
320    - Use latest BoringSSL.
321
3222019-10-08
323    - 2.4.4
324    - [API] Add lsquic_alpn2ver() to aid parsing Alt-Svc header.
325    - [BUGFIX] NULL dereference when H3 frame header would be split.
326    - [BUGFIX] Do not close fixed-size H3 frame prematurely.
327    - [BUGFIX] Allow PING frames in IETF mini conn.
328    - [BUGFIX] Mini conns: don't send any packets after receiving
329      CONNECTION_CLOSE.
330    - [BUGFIX] Client migration: reserve slot for DCID from transport params.
331    - [BUGFIX] Allow max_early_data_size=0 -- early_data might not be there.
332    - [BUGFIX] Use an invalid stream number to reset BPT cache (zero is now a
333      valid stream number).
334    - [SPEC] Use FINAL_SIZE_ERROR when FIN mismatch is detected.
335    - [OPTIMIZATION] Closed connection only gets one chance to send packets.
336    - [OPTIMIZATION] Flush headers stream before packetizing stream data.
337    - [OPTIMIZATION] process QPACK encoder STREAM frames immediately.
338    - Update ls-qpack to v0.10.1.
339
3402019-09-30
341    - 2.4.3
342    - Add GQUIC versions to the list of h3 ALPNs for Alt-Svc header.
343      For example, h3-Q043.  Chrome will switch to using this format at
344      some point in the future.
345    - [BUGFIX] Send correct value in max_streams_uni transport param
346    - [SPEC] Abort IETF QUIC connection if max_early_data_size is not set
347      to 0xFFFFFFFF
348
3492019-09-23
350    - 2.4.2
351    - [BUGFIX] H3 framing: fix zero-byte write when space is available
352    - [BUGFIX] Don't send STREAM frame when incoming unidirectgional stream
353      is closed
354    - [BUGFIX] Cancel all pending writes by stream reset by a GOAWAY
355    - [BUGFIX] Fix use-after-free in IETF full conn
356    - [OPTIMIZATION] Wait for session tickets for two seconds and then drop
357      SSL object and crypto streams.
358
3592019-09-18
360    - 2.4.0
361    - [FEATURE] QUIC and HTTP/3 Internet Draft 23 support
362
3632019-09-13
364    - 2.3.1
365    - [BUGFIX] Fix memory leaks
366    - [BUGFIX] Fix unit tests
367
3682019-09-12
369    - 2.3.0
370    - [FEATURE] BBR congestion control is on by default
371    - [BUGFIX] BBR app-limited logic
372    - [BUGFIX] Fix uninitialized warnings in IETF
373    - [BUGFIX] Update ls-qpack to v0.9.14
374    - [CLEANUP] Code cleanup
375
3762019-09-11
377    - 2.2.0
378    - [FEATURE] Server code is included in the library
379    - [FEATURE] IETF QUIC and HTTP/3 Support (ID-22)
380
3812019-05-13
382    - 1.21.2
383    - [OPTIMIZATION] HPACK: use history to improve compression performance
384
3852019-05-06
386    - 1.21.1
387    - [BUGFIX] If FIN or RST not received, don't delay stream destruction.
388    - [OPTIMIZATION] Speed up HPACK encoder by using same hash value to
389      search static and dynamic tables.
390
3912019-04-12
392    - 1.21.0
393    - [FEATURE] Add qlog log module.
394
3952019-04-01
396    - 1.20.0
397    - [FEATURE] Add support for Q046.
398
3992019-03-19
400    - 1.19.6
401    - [BUGFIX] Ensure that Largest Observed does not decrease in ACKs we
402      send.  ACK frames placed in packets in buffered queues (optimization
403      introduced in 1.17.15) can be preceded by an ACK frame generated later.
404      In this case, the older ACK frame should not be sent out, as Chromium-
405      based servers flags decrease in the ACK frame's Largest Observed value
406      as an error.
407
4082019-03-05
409    - 1.19.5
410    - [BUGFIX] Use correct public key from PUBS based on KEXS index.
411    - [BUGFIX] Check flags before dispatching writes, avoiding assert.
412    - [BUGFIX] Set :scheme to "https" (instead of "HTTP").
413
4142019-02-25
415    - 1.19.4
416    - [BUGFIX] Check buffer bounds when looking up version in 0-RTT blob.
417    - [BUGFIX] http_client: don't fetch 0-rtt info if handshake failed.
418    - Log number of pacer calls at DEBUG, rather than NOTICE, level.
419
4202019-02-18
421    - 1.19.3
422    - [BUGFIX] Q044: don't encode packet number in 6 bytes.  Six-byte
423      packet number encoding does not exist in Q044.  This fixes a
424      regression introduced in '[BUGFIX] Buffered packets can contain
425      ACK frames' -- we need to keep QUIC version in mind when selecting
426      the longest possible packet number encoding used for the buffered
427      packet that carries the ACK.
428    - [BUGFIX] Do not increase CWND when timeout occurs.
429    - http_client: support setting handshake timeout on command line.
430      Use -o handshake_to=timeout.
431    - http_client: use -k to connect UDP socket to pick up ICMP errors.
432    - http_client: allow pathless mode, when only handshake is performed
433      without issuing any requests.  This can be done by simply not
434      specifying a -p flag on the command line.
435
4362019-02-11
437    - 1.19.2
438    - [BUGFIX] Begin negotiation with version provided in 0-RTT info.
439    - [BUGFIX] Version checking in zero_rtt deserialize function.
440
4412019-02-04
442    - 1.19.1
443    - [BUGFIX] Fix Windows build.
444
4452019-02-04
446    - 1.19.0
447    - [FEATURE, API Change] 0-RTT support.  Add function to export 0-RTT
448      information; it can be supplied to a subsequent connect() call.
449    - [FEATURE] Add -0 flag to http_client to exercise 0-RTT support.
450    - [BUGFIX] Resuscitate the Windows build.
451    - [BUGFIX] Send HTTP settings (max header list size) if necessary.
452    - [BUGFIX] Buffered packets can contain ACK frames.
453    - [BUGFIX] Make packet writeable once all STREAM frames are elided.
454    - [BUGFIX] Fix potential null dereference when realloc fails.
455    - cmake: simplify build configuration.
456
4572019-01-28
458    - 1.18.0
459    - [API Change] Can specify clock granularity in engine settings.
460    - [BUGFIX] Pacer uses fixed clock granularity.  Since the change on
461      2018-04-09, it is not necessary to try to approximate the next tick
462      time in the pacer: it can use fix clock granularity specified by
463      the user.
464    - [BUGFIX] Do not tick constantly before handshake is done.
465    - [BUGFIX] Do not exit tick prematurely: reuse packet with ACK.  Even
466      if we cannot allocate *more* packets, we could still be able to write
467      to one already allocated.
468    - [BUGFIX] Do not schedule pacer if there are no lost packets.
469
4702019-01-17
471    - 1.17.15
472    - [BUGFIX] http_client: make sure only one read per on_read() callback
473      is performed in the header conversion bypass (-B) mode.
474    - http_client: with -E, assign random priority when stream is created.
475    - [OPTIMIZATION] On immediate write, place an ACK frame into the first
476      buffered packet if an ACK is queued.  This reduces the number of
477      standalone ACK packets.
478    - [OPTIMIZATION] Allow placing more than one STREAM frame from the same
479      stream into an outgoing packet.  This change minimizes the number of
480      buffered packets required to store several small HTTP messages by
481      virtue of allowing more than one STREAM frame from HEADERS stream in
482      the same packet.
483    - [OPTIMIZATION] Flush headers when writing to buffered packets.  This
484      causes the headers to be written to the same buffered packet queue,
485      thereby improving packet utilization, especially for small HTTP
486      messages.
487
4882019-01-16
489    - 1.17.14
490    - [FEATURE] http_client can now collect stats: time to connect, TTFB,
491      time to download, requests per seconds, and bandwidth.  See -t flag.
492    - [BUGFIX] http_client: -B, -K, and -r can be used at the same time.
493    - [BUGFIX] http_client: do not display cert chain before each request.
494      Now this is only done once per connection, if the handshake is
495      successful and -a option is given.
496    - [BUGFIX] Do not wait to dispatch on_close() after reading.  If a
497      stream is scheduled to be closed after on_read() callback returns,
498      close it immediately instead of waiting until the end of the tick.
499      If client creates new request from on_close() event, they will be
500      processed in the same tick instead of waiting for the next one.
501    - [BUGFIX] HEADERS stream is critical: always treat it with highest
502      priority.
503
5042019-01-10
505    - 1.17.12
506    - [FEATURE] http_client can now issue parallel requests in the context
507      of a single connection.  See -w option.
508
5092019-01-03
510    - 1.17.11
511    - Fix strict aliasing warning in optimized compilation.
512
5132018-12-27
514    - 1.17.10
515    - Fix the example program to be able to use parallel connections
516      again.  (See the -n argument.)
517
5182018-12-18
519    - 1.17.9
520    - [BUGFIX] Engine: reduce minimum batch size from 256 to 4
521
5222018-12-10
523    - 1.17.8
524    - [BUGFIX] Fix compilation on FreeBSD and 32-bit Linux
525
5262018-12-03
527    - 1.17.7
528    - [BUGFIX] Do not unset PING alarm before ringing expired alarms.
529      This prevented PING from ever being sent.
530
5312018-11-29
532    - 1.17.6
533    - Add failsafe: resume sending packets after some time
534
535      The change puts a 1-second limit on the amount of time the engine
536      will not send packets after some packets are delayed.  This makes
537      the library robust in case the user does not unblock the engine
538      explicitly using lsquic_engine_send_unsent_packets() call.
539
540    - [BUGFIX] Handle corner cases in send controller when packets are
541      a) delayed or b) dropped during repackaging.
542    - [BUGFIX] Memory leak: destroy buffered packets during controller
543      cleanup.
544
5452018-11-16
546    - 1.17.3
547    - [BUGFIX] Do not send STOP_WAITING frames when using Q044
548
5492018-10-19
550    - 1.17.2
551    - [BUGFIX] Memory leak in test_frame_rw unit test.
552    - [BUGFIX] Parsing packets with short IETF header: do not overwrite
553      flags.  (Only a problem in unit tests -- benign otherwise.)
554
5552018-10-16
556    - 1.17.0
557    - [API Change] Packet out Memory Interface (PMI) update:
558      - Split PMI pool return into pmi_release and pmi_return
559      - PMI callbacks take peer_ctx and is_ipv6 arguments
560    - [BUGFIX] Fix use-after-free when certificate is updated
561    - Silence gcc warning in optimized mode by performing useless
562      initialization
563    - cmake: use the standard variable CMAKE_BUILD_TYPE instead of
564      DEVEL_MODE
565
5662018-10-03
567    - 1.16.0
568    - [API Change] Add lsquic_conn_n_avail_streams()
569    - [BUGFIX] only dispatch crypto stream read events if WANT_READ is on
570
5712018-09-27
572    - 1.15.0
573    - [API Change] Add LSCONN_ST_PEER_GOING_AWAY to the list of conn statuses
574    - [BUGFIX] free uncompressed headers correctly when error occurs
575
5762018-09-12
577    - 1.14.3
578    - [BUGFIX] Do not abort conn on STREAM frame for a reset stream
579    - [BUGFIX] Drop packets that would become empty due to repackaging.
580      Packets on the scheduled queue may be marked for repackaging.
581      Frames such as ACK frame that are never resent are removed from
582      repackaged packets.  We must check that the newly repackaged packet
583      would not be empty.  If it would be, it is destroyed instead and
584      the next packet on the scheduled queue is used.  Note that this
585      change only affects the logic to return the next packet to be sent.
586      Lost packets that are being rescheduled are already processed in
587      this fashion.
588    - Byteswap CID before logging it - this makes it match Chrome CIDs.
589      (Except Q035, which is the last little-endian GQUIC version we
590      support.)
591
5922018-09-06
593    - 1.14.0
594    - [API Change] Disable packet sending if full batch cannot be sent
595      If lsquic_packets_out_f() cannot send the whole batch, disable
596      packet sending until lsquic_engine_send_unsent_packets() is called.
597    - [BUGFIX] Handle case when STREAM frame does not fit.
598    - [BUGFIX] Always allow incoming STREAM frames to overlap.  Peers
599      may send overlapping STREAM frames even if using versions older
600      than Q043.
601    - Custom header set fixes:
602      - set "FIN reached" flag when custom header with FIN flag is
603        claimed;
604      - do not return custom header set for a reset stream.
605
6062018-08-27
607
608    - 1.13.0
609    - [FEATURE, API Change] Add ability to create custom header set
610      objects via callbacks.  This avoids reading and re-parsing
611      headers from the stream.
612
6132018-08-27
614
615    - 1.12.4
616    - Fix memory leak when engine is destroyed
617    - Fix memory leak in http_client
618    - Fix gcc warning in unit tests
619
6202018-08-22
621
622    - 1.12.3
623    - [BUGFIX] Fix duplicate STREAM frame detection
624
6252018-08-20
626
627    - 1.12.2
628    - [BUGFIX] Update count of scheduled bytes when adjusting size of
629      an already-scheduled packet.
630    - Emit info instead of warning messages when stream is used in
631      unexpected ways.
632
6332018-08-17
634
635    - 1.12.0
636    - [FEATURE, API Change] Add support for certificate verification
637
6382018-08-16
639
640    - 1.11.1
641    - [BUGFIX] Fix STOP_WAITING frame processing in the new Q044 code
642
6432018-08-15
644
645    - 1.11.0
646    - [FEATURE] Add support for Q044.
647
6482018-08-09
649
650    - 1.10.2
651    - [BUGFIX] Don't go over limit when creating delayed streams
652
6532018-07-10
654
655    - 1.10.1
656    - [BUGFIX]  process connections after each batch of packets is read
657      This avoids a problem of accumulating a very large list of packets
658      (possible when speeds are high and socket's receive buffer is large)
659      and processing it all at once.
660    - If glibc is older than 2.17, link with rt.  This is necessary for
661      clock_getres(2).
662    - Add version macros to lsquic.h; remove unnecessary includes.
663
6642018-06-13
665
666    - [BUGFIX] allow multiple parallel connections by default
667
668      Use the original method of tracking connections by CIDs by default.
669      If zero-sized CID support is turned on, connections are tracked by
670      the address.  A new connection is not created if another connection
671      is using the same network address
672
6732018-05-30
674
675    - [FEATURE, API CHANGE] Support zero-sized CIDs in received packets
676
6772018-05-24
678
679    - Close connection properly when packet encryption fails
680
6812018-05-23
682
683    - [BUGFIX] Do not produce packet sequence gaps due to delayed packets
684
6852018-05-21
686
687    - [API Change] Add optional callback to call when handshake is done
688    - [API Change, BUGFIX] After send failure, wait until transport available
689
6902018-05-18
691
692    - [API] Expose useful lsquic_ver2str[] in lsquic.h
693    - [BUGFIX] Do not produce packet sequence gaps due to STREAM frame elision
694    - Improve checks of number of incoming streams limit and associated
695      error reporting.
696    - [BUGFIX] Command-line option `-6` now works correctly.
697
6982018-05-16
699
700    - [FEATURE] DNS resolution
701    - [BUGFIX] Frame insertion mis-ID as overlap instead of dup
702    - http_client: fix priority range generated by -E flag
703
7042018-05-09
705
706    - [FEATURE] Add support for Q043.
707    - Support for versions Q037, Q038, Q041, and Q042 has been removed.
708    - Fix typo in debug message.
709    - Fix code indentation.
710    - Add /* fallthru */ comment to stop newer gcc from complaining.
711    - Logger: fix compilation of optimized Windows build.
712
7132018-05-04
714
715    - [FEATURE] Add support for Q042.
716    - Remove comment: MSPC is obsolete (no code changes)
717    - Prog: use lsquic_str2ver() when processing -o version flag
718    - Remove unused CTIM and SRBF transport parameters
719    - Disable QUIC versions Q037 and Q038 by default
720    - Fix Windows compilation by including compat header file in
721      lshpack.c
722    - Address warnings produced by newer versions of gcc
723    - Future-proof: turn off -Werror
724
7252018-05-02
726
727    - [BUGFIX] Make lsquic_conn_quic_version() available
728    - Switch to using ls-hpack 1.1
729    - [BUGFIX] Do not ignore stream resets after receiving FIN
730
7312018-04-27
732
733    - HPACK: do not allow header block to end with table size update.
734
7352018-04-25
736
737    - [BUGFIX] Do not create gap in sent packnos when squeezing delayed
738      packets.
739    - [BUGFIX] sendctl checks for all unacked bytes, not just retx bytes.
740    - [BUGFIX] connections with blocked scheduled packets are not tickable
741      for sending.
742    - [BUGFIX] Conn is tickable if it wants to send a connection-level
743      frame.
744
7452018-04-23
746
747    - Fix busy loop: tickable must make progress.  When connection is
748      self-reporting as tickable, it must make progress when ticked.  There
749      are two issues:
750        1. If there are buffered packets, the connection is only tickable if
751           they can be sent out.
752        2. A connection is tickable if there are streams on the servicing
753           queue.  When the tick occurs, we must service the stream
754           independent of whether any packets are sent.
755    - Fix assertion in pacer which can be incorrect under some
756      conditions.
757    - cmake: do not turn on address sanitizer if in Travis.
758
7592018-04-20
760
761    - [BUGFIX] Fix bug in lsquic_engine_connect() exposed by yesterday's
762      changes.
763
7642018-04-19
765
766    - [BUGFIX] Add connection to Tickable Queue on stream write
767    - cmake: use MSVC variable instead of trying to detect
768    - engine: improve connection incref/decref logging
769    - stream: don't ignore errors that may occur on triggered flush
770    - connection: remove obsolete method
771    - engine: indicate connection as tickable if previous call went
772      over threshold
773
7742018-04-09
775
776    [API Change, OPTIMIZATION] Only process conns that need to be processed
777
778    The API is simplified: do not expose the user code to several
779    queues.  A "connection queue" is now an internal concept.
780    The user processes connections using the single function
781    lsquic_engine_process_conns().  When this function is called,
782    only those connections are processed that need to be processed.
783    A connection needs to be processed when:
784
785        1. New incoming packets have been fed to the connection.
786        2. User wants to read from a stream that is readable.
787        3. User wants to write to a stream that is writeable.
788        4. There are buffered packets that can be sent out.  (This
789           means that the user wrote to a stream outside of the
790           lsquic library callback.)
791        5. A control frame (such as BLOCKED) needs to be sent out.
792        6. A stream needs to be serviced or delayed stream needs to
793           be created.
794        7. An alarm rings.
795        8. Pacer timer expires.
796
797    To achieve this, the library places the connections into two
798    priority queues (min heaps):
799
800        1. Tickable Queue; and
801        2. Advisory Tick Time queue (ATTQ).
802
803    Each time lsquic_engine_process_conns() is called, the Tickable
804    Queue is emptied.  After the connections have been ticked, they are
805    queried again: if a connection is not being closed, it is placed
806    either in the Tickable Queue if it is ready to be ticked again or
807    it is placed in the Advisory Tick Time Queue.  It is assumed that
808    a connection always has at least one timer set (the idle alarm).
809
810    The connections in the Tickable Queue are arranged in the least
811    recently ticked order.  This lets connections that have been quiet
812    longer to get their packets scheduled first.
813
814    This change means that the library no longer needs to be ticked
815    periodically.  The user code can query the library when is the
816    next tick event and schedule it exactly.  When connections are
817    processed, only the tickable connections are processed, not *all*
818    the connections.  When there are no tick events, it means that no
819    timer event is necessary -- only the file descriptor READ event
820    is active.
821
822    The following are improvements and simplifications that have
823    been triggered:
824
825        - Queue of connections with incoming packets is gone.
826        - "Pending Read/Write Events" Queue is gone (along with its
827          history and progress checks).  This queue has become the
828          Tickable Queue.
829        - The connection hash no longer needs to track the connection
830          insertion order.
831
8322018-04-02
833
834    - [FEATURE] Windows support
835
836    - Reduce stack use -- outgoing packet batch is now allocated on the heap.
837
8382018-03-09
839
840    - [OPTIMIZATION] Merge series of ACKs if possible
841
842      Parsed single-range ACK frames (that is the majority of frames) are
843      saved in the connection and their processing is deferred until the
844      connection is ticked.  If several ACKs come in a series between
845      adjacent ticks, we check whether the latest ACK is a strict superset
846      of the saved ACK.  If it is, the older ACK is not processed.
847
848      If ACK frames can be merged, they are merged and only one of them is
849      either processed or saved.
850
851    - [OPTIMIZATION] Speed up ACK verification by simplifying send history.
852
853      Never generate a gap in the sent packet number sequence.  This reduces
854      the send history to a single number instead of potentially a series of
855      packet ranges and thereby speeds up ACK verification.
856
857      By default, detecting a gap in the send history is not fatal: only a
858      single warning is generated per connection.  The connection can continue
859      to operate even if the ACK verification code is not able to detect some
860      inconsistencies.
861
862    - [OPTIMIZATION] Rearrange the lsquic_send_ctl struct
863
864      The first part of struct lsquic_send_ctl now consists of members that
865      are used in lsquic_send_ctl_got_ack() (in the absense of packet loss,
866      which is the normal case).  To speed up reads and writes, we no longer
867      try to save space by using 8- and 16-bit integers.  Use regular integer
868      width for everything.
869
870    - [OPTIMIZATION] Cache size of sent packet.
871
872    - [OPTIMIZATION] Keep track of the largest ACKed in packet_out
873
874      Instead of parsing our own ACK frames when packet has been acked,
875      use the value saved in the packet_out structure when the ACK frame
876      was generated.
877
878    - [OPTIMIZATION] Take RTT sampling conditional out of ACK loop
879
880    - [OPTIMIZATION] ACK processing: only call clock_gettime() if needed
881
882    - [OPTIMIZATION] Several code-level optimizations to ACK processing.
883
884    - Fix: http_client: fix -I flag; switch assert() to abort()
885
8862018-02-26
887    - [API Change] lsquic_engine_connect() returns pointer to the connection
888      object.
889    - [API Change] Add lsquic_conn_get_engine() to get engine object from
890      connection object.
891    - [API Change] Add lsquic_conn_status() to query connection status.
892    - [API Change] Add add lsquic_conn_set_ctx().
893    - [API Change] Add new timestamp format, e.g. 2017-03-21 13:43:46.671345
894    - [OPTIMIZATION] Process handshake STREAM frames as soon as packet
895      arrives.
896    - [OPTIMIZATION] Do not compile expensive send controller sanity check
897      by default.
898    - [OPTIMIZATION] Add fast path to gquic_be_gen_reg_pkt_header.
899    - [OPTIMIZATION] Only make squeeze function call if necessary.
900    - [OPTIMIZATION] Speed up Q039 ACK frame parsing.
901    - [OPTIMIZATION] Fit most used elements of packet_out into first 64 bytes.
902    - [OPTIMIZATION] Keep track of scheduled bytes instead of calculating.
903    - [OPTIMIZATION] Prefetch next unacked packet when processing ACK.
904    - [OPTIMIZATION] Leverage fact that ACK ranges and unacked list are.
905      ordered.
906    - [OPTIMIZATION] Reduce function pointer use for STREAM frame generation
907    - Fix: reset incoming streams that arrive after we send GOAWAY.
908    - Fix: delay client on_new_conn() call until connection is fully set up.
909    - Fixes to buffered packets logic: splitting, STREAM frame elision.
910    - Fix: do not dispatch on_write callback if no packets are available.
911    - Fix WINDOW_UPDATE send and resend logic.
912    - Fix STREAM frame extension code.
913    - Fix: Drop unflushed data when stream is reset.
914    - Switch to tracking CWND using bytes rather than packets.
915    - Fix TCP friendly adjustment in cubic.
916    - Fix: do not generate invalid STOP_WAITING frames during high packet
917      loss.
918    - Pacer fixes.
919
9202017-12-18
921
922    - Fix: better follow cubic curve after idle period
923    - Fix: add missing parts to outgoing packet splitting code
924    - Fix: compilation using gcc 4.8.4
925
9262017-10-31
927
928    - Add APIs.txt -- describes LSQUIC APIs
929
9302017-10-31
931
932    - [API Change] Sendfile-like functionality is gone.  The stream no
933      longer opens files and deals with file descriptors.  (Among other
934      things, this makes the code more portable.)  Three writing functions
935      are provided:
936
937        lsquic_stream_write
938        lsquic_stream_writev
939        lsquic_stream_writef    (NEW)
940
941      lsquic_stream_writef() is given an abstract reader that has function
942      pointers for size() and read() functions which the user can implement.
943      This is the most flexible way.  lsquic_stream_write() and
944      lsquic_stream_writev() are now both implemented as wrappers around
945      lsquic_stream_writef().
946
947    - [OPTIMIZATION] When writing to stream, be it within or without the
948      on_write() callback, place data directly into packet buffer,
949      bypassing auxiliary data structures.  This reduces amount of memory
950      required, for the amount of data that can be written is limited
951      by the congestion window.
952
953      To support writes outside the on_write() callback, we keep N
954      outgoing packet buffers per connection which can be written to
955      by any stream.  One half of these are reserved for the highest
956      priority stream(s), the other half for all other streams.  This way,
957      low-priority streams cannot write instead of high-priority streams
958      and, on the other hand, low-priority streams get a chance to send
959      their packets out.
960
961      The algorithm is as follows:
962
963      - When user writes to stream outside of the callback:
964        - If this is the highest priority stream, place it onto the
965          reserved N/2 queue or fail.
966            (The actual size of this queue is dynamic -- MAX(N/2, CWND) --
967             rather than N/2, allowing high-priority streams to write as
968             much as can be sent.)
969        - If the stream is not the highest priority, try to place the
970          data onto the reserved N/2 queue or fail.
971      - When tick occurs *and* more packets can be scheduled:
972        - Transfer packets from the high N/2 queue to the scheduled
973          queue.
974        - If more scheduling is allowed:
975          - Call on_write callbacks for highest-priority streams,
976            placing resulting packets directly onto the scheduled queue.
977        - If more scheduling is allowed:
978          - Transfer packets from the low N/2 queue to the scheduled
979            queue.
980        - If more scheduling is allowed:
981          - Call on_write callbacks for non-highest-priority streams,
982            placing resulting packets directly onto the scheduled queue
983
984      The number N is currently 20, but it could be varied based on
985      resource usage.
986
987    - If stream is created due to incoming headers, make headers readable
988      from on_new.
989
990    - Outgoing packets are no longer marked non-writeable to prevent placing
991      more than one STREAM frame from the same stream into a single packet.
992      This property is maintained via code flow and an explicit check.
993      Packets for stream data are allocated using a special function.
994
995    - STREAM frame elision is cheaper, as we only perform it if a reset
996      stream has outgoing packets referencing it.
997
998    - lsquic_packet_out_t is smaller, as stream_rec elements are now
999      inside a union.
1000
10012017-10-12
1002
1003    - Do not send RST_STREAM when stream is closed for reading
1004    - Raise maximum header size from 4K to 64K
1005    - Check header name and value lengths against maximum imposed by HPACK
1006    - Fix NULL dereference in stream flow controller
1007
10082017-10-09
1009
1010    - Hide handshake implementation behind a set of function pointers
1011    - Use monotonically increasing clock
1012    - Make sure that retx delay is not larger than the max of 60 seconds
1013
10142017-09-29
1015
1016    - A few fixes to code and README
1017
10182017-09-28
1019
1020    - Add support for Q041; drop support for Q040
1021
10222017-09-27
1023
1024    - Fix CMakeLists.txt: BoringSSL include and lib was mixed up
1025
10262017-09-26
1027
1028    - Add support for Mac OS
1029    - Add support for Raspberry Pi
1030    - Fix BoringSSL compilation: include <openssl/hmac.h> explicitly
1031
10322017-09-22
1033
1034    - Initial release
1035