CHANGELOG revision 992bbcdb
12020-03-13
2    - 2.13.2
3    - [BUGFIX] Use of new lsxpack_header API's hsi_prepare_decode().
4
52020-03-12
6    - 2.13.1
7    - [API] Use lsxpack_header structure to process incoming headers.
8    - [BUGFIX] Fix assertion when zero-padding Initial packet.
9    - [BUGFIX] Use idle timeout before we learn of peer's value.
10    - Use ls-hpack 2.0.1 -- has lsxpack_header changes.
11    - Use ls-qpack 0.14.0 -- new, common with ls-hpack, XXH seed (not
12      used yet).
13    - Code cleanup: prefix exported functions with "lsquic_".
14
152020-03-02
16    - 2.12.0
17    - [FEATURE] QUIC timestamps extension.
18    - [API] New: ea_alpn that is used when not in HTTP mode.
19    - [BUGFIX] SNI is mandatory only for HTTP/3 and gQUIC.
20    - [BUGFIX] Benign double-free -- issue #110.
21    - [BUGFIX] Printing of transport parameters.
22
232020-02-24
24    - 2.11.1
25    - [FEATURE] QUIC and HTTP/3 Internet Draft 27 support.
26    - [FEATURE] Add experimental delayed ACKs extension.
27    - Drop support for Internet Draft 24.
28    - Code cleanup.
29
302020-02-14
31    - 2.10.6
32    - [BUGFIX] HTTP/3 framing: don't misinterpret rare occurence as error.
33    - [BUGFIX] Send gap warning due to missing poisoned packet.
34    - Stream unit test for scenario in issue #106.
35
362020-02-13
37    - 2.10.5
38    - [BUGFIX] BBR: call cci_sent() with correct arguments and at correct
39      time.
40    - Refactor transport parameters module.
41    - Minor code cleanup.
42
432020-02-11
44    - 2.10.4
45    - [BUGFIX] Send HANDSHAKE_DONE only after Finished is received.
46    - [BUGFIX] Don't treat garbage UDP padding as library error; ignore
47      it instead.
48    - [BUGFIX] Fix compilation on FreeBSD (missing header).
49    - Code cleanup: remove unnecessary #includes.
50
512020-01-31
52    - 2.10.3
53    - [BUGFIX] Cancel path responses and challenges on old path when
54      switching to new path
55    - Logging network path information.
56
572020-01-30
58    - 2.10.2
59    - [BUGFIX] Do not delay ACKs for Initial and Handshake packets.
60    - [BUGFIX] Send PATH_CHALLENGE if path changed before mini conn
61      promotion.
62    - Logging improvements.
63    - http_client: discard data faster.
64
652020-01-29
66    - 2.10.1
67    - [BUGFIX] Coalesced packets could get longer than normal packet
68      size.
69    - Add spin bit configuration option es_spin (-o spin=[01]).
70    - Disable spin bit in 1/16 of connections.
71    - Improve logging a bit.
72
732020-01-28
74    - 2.10.0
75    - [FEATURE] QUIC and HTTP/3 Internet Draft 25 support.
76    - [API] Drop support for ID-23.
77    - [BUGFIX] Set key phase bit on outgoing packets correctly.
78    - Code cleanup.
79
802020-01-20
81    - 2.9.0
82    - [API] Drop support for Q039.
83    - Improve ACK-queuing logic.  Send an ACK once in a while if
84      peer keeps on sending non-ack-eliciting packets.
85    - Improve Alt-Svc string: Q050 and later are not included in
86      the old-style "quic" string.
87    - Send stateless resets if connection could not be promoted.
88    - Schedule MAX_DATA if needed when DATA_BLOCKED is received.
89    - Use ls-qpack 0.11.2 -- needed for server push optimization.
90    - Code cleanup: handle some error cases, improve logging.
91
922020-01-16
93    - 2.8.9
94    - [BUGFIX] Use ls-qpack 0.11.1
95    - [OPTIMIZATION] Generate random bytes in batches.
96    - Change loss_bits transport parameter ID to 0x1057 following
97      latest draft.
98    - Randomize period with which PINGs are sent to elicit ACKs.
99    - Some refactoring and code cleanup.
100
1012020-01-14
102    - 2.8.8
103    - [BUGFIX] Invalid read when parsing IETF transport parameters
104      (this was benign).
105    - [OPTIMIZATION] Frame bundling when using buffered packets in
106      IETF QUIC: a) flush QPACK decoder stream and b) include ACKs
107      in opportunistic fashion.
108    - Fix HTTP/3 framing unit test.
109    - Code cleanup.
110
1112020-01-09
112    - 2.8.7
113    - [BUGFIX] Initial packet size check for IETF mini conn applies to
114      UDP payload, not QUIC packet.
115    - Support old and new school loss_bits transport parameter.
116    - Use Q run length of 64 as suggested in the loss bits Draft.
117    - Undo square wave count when packet is delayed.
118    - Code cleanup; minor fixes.
119
1202020-01-06
121    - 2.8.5
122    - [HTTP3] Verify number of bytes in incoming DATA frames against
123      content-length.
124    - [HTTP3] Stop issuing streams credits if peer stops opening QPACK
125      decoder window.  This addresses a potential attack whereby client
126      can cause the server to keep allocating memory.  See Security
127      Considerations in the QPACK draft.
128    - [BUGFIX] Mini conn: don't shorten max packet size for Q050 and later.
129    - [BUGFIX] Init IETF connection flow controller using correct setting.
130    - [BUGFIX] Fix unintended sign extension when removing header protection.
131    - Code cleanup and minor fixes.
132
1332019-12-30
134    - 2.8.1
135    - [FEATURE] Use occasional packet number gaps to detect optimistic
136      ACK attacks.
137    - [BUGFIX] Q050 client: all packet numbers are in the App PNS.
138    - [OPTIMIZATION] Merge multi-range ACK frames, not just single-range
139      ACK frames.
140    - IETF QUIC: use RTT estimate in ack timeout calculation.
141    - IETF handshake: abort conn when unexpected errors occur.
142    - Use PING rather than MAX_DATA frames to elicit ACKs from peer.
143    - Server: enforce 1200 byte Initial minimum packet size.
144    - [CLEANUP] Remove code to disable gQUIC crypto.
145    - [CLEANUP] Remove n_timestamps from ACK info struct.
146    - Optimize driver: reuse previous ancillary message when possible.
147
1482019-12-23
149    - 2.8.0
150    - [FEATURE] Add support for Q050.
151    - [OPTIMIZATION] Reduce mallocs in gQUIC handshake.
152    - [BUGFIX] Disable redo of failed STREAM frame insertion with debug
153      logging.
154
1552019-12-18
156    - 2.7.3
157    - [DEBUG] Further dedup next advisory tick messages when reason is
158      the same.
159    - [BUGFIX] Update size of `a` array in TP struct.  Fixes (benign)
160      GitHub bug #94.
161    - Use Cubic by default again instead of BBR, as it delivers more
162      consistent performance.
163
1642019-12-11
165    - 2.7.2
166    - [BUGFIX] Send controller: update scheduled bytes when DCID length
167      changes (IETF client).
168    - [BUGFIX] Drop alarm check from sanity test.  It no longer works now
169      that we use loss chains.
170    - [PORTABILITY] Fix build on Alpine Linux.
171    - [PORTABILITY] Fix build using XCode.
172    - Client initial DCID length: use RAND_bytes() instead of rand(3).
173    - Add unit tests for connection min heap.
174    - [DEBUG] Log CID in gQUIC handshake module
175    - [DEBUG] Turn on extra checks for IETF client send controller.
176    - [DEBUG] Dedup next advisory tick messages when reason is IDLE timer.
177    - [DEBUG] QPACK decoder handler: log header error code.
178
1792019-12-05
180    - 2.7.1
181    - [BUGFIX] client: don't call ignore_init() in middle of batch send.
182      ignore_init() makes an assumption that the send controller has access
183      to all outgoing packets.  This change wraps a few IETF full connection
184      methods to delay calling ignore_init() until the engine returns all
185      outgoing packets that were batched.
186    - [BUGFIX] set errno to EAGAIN if sendmmsg() can't send all of them.
187      This needs to be done because the value of errno may be lost on
188      some platforms.
189    - [BUGFIX] Typo that set all bits in sm_qflags lead to crashes.
190    - [BUGFIX] Do not cancel header block processing after failure, as
191      QPACK releases the reference in that case.
192    - [CLEANUP] IETF encrypt: replace assert(0) with a warning.
193    - Several small improvements to the test server.
194
1952019-11-27
196    - 2.7.0
197    - [API, FEATURE] Close connection immediately when ea_packets_out()
198      fails with errno != EAGAIN.  The API change is that errno is now
199      examined.  Make sure to set it if using something other than
200      sendmsg() to send packets.
201    - [CLEANUP] Immediate close logic in IETF full conn.
202    - [CLEANUP] Fix bogus warning about uninitialized `pair' variable.
203
2042019-11-22
205    - 2.6.7
206    - [FEATURE] Implement the QL extension (offered by default).
207    - [BUGFIX] Abort when encountering unexpected HTTP/3 frames.
208    - [BUGFIX] Acknowledge (QPACK) HTTP/3 trailers correctly.
209    - [DEBUG] Turn on debug message for next advisory tick.
210
2112019-11-20
212    - 2.6.6
213    - [BUGFIX] Using HTTP/3 to HTTP/1.x converter.
214    - [BUGFIX] Truncate log messages instead of throwing them away.
215
2162019-11-15
217    - 2.6.5
218    - [BUGFIX] High priority buffered packet queue length.
219    - [BUGFIX] Rain time calculation: max_ack_delay is in milliseconds.
220
2212019-11-12
222    - 2.6.3
223    - [BUGFIX] Close DATA frames with empty payload correctly.
224
2252019-11-11
226    - 2.6.2
227    - [BUGFIX] SCID!=ODCID rule applies to Retry packets, not regular
228      packets.
229    - [BUGFIX] Zero-RTT: BoringSSL no longer flips read/write secrets.
230    - [BUGFIX] Truncate ACK frame rather instead of aborting IETF
231      connection.
232    - [BUGFIX] Client: don't send duplicate reset tokens.
233    - [BUGFIX] Remove invalid assertion in H3 framing code.
234    - Silence a warning in send ctl by restructuring switch() statement.
235
2362019-11-08
237    - 2.6.1
238    - [BUGFIX] set retry token on all resubmitted packets.
239    - Event log: log sent packet flags.  In particular, this allows one
240      to see whether token was sent.
241    - Don't migrate client if es_allow_migration is false.
242
2432019-11-07
244    - 2.6.0
245    - [FEATURE] QUIC and HTTP/3 Internet Draft 24 support
246
2472019-11-07
248    - 2.5.2
249    - [BUGFIX] argument order to gQUIC client constructor.  Regression
250      introduced in 2.5.0.
251    - [BUGFIX] split buffered packet error recovery: destroy the correct
252      packet.
253
2542019-11-04
255    - 2.5.1
256    - [BUGFIX] Fix double-free when emptying a packet number space.
257    - [BUGFIX] http_server: fix md5sum handler: handle EOF correctly.
258    - [BUGFIX] Use random values in bits 4 and 5 of the first byte of
259      verneg packets (regression introduced in 2.5.0).
260    - [OPTIMIZATION] Don't compile in expensive attq checks by default.
261    - [OPTIMIZATION] http_server: compile regexes only once.
262
2632019-10-31
264    - 2.5.0
265    - [API] lsquic_engine_connect() can now be passed QUIC version to use.
266    - [OPTIMIZATION] Queue opportunistic ACKs if there is data to be sent.
267    - [BUGFIX] Don't evict streams from priority iterator if there is
268      only one queue.
269    - [OPTIMIZATION, BUGFIX] Several other optimizations and bug fixes.
270    - Use ls-qpack v0.10.7.
271
2722019-10-24
273    - 2.4.10
274    - [BUGFIX] IETF QUIC server: fix uninitialized variable use.
275    - [BUGFIX] make sure TLSv1.3 is not disabled in SSL object.
276    - [BUGFIX] Use issuer name and serial number to cache certs (SKID
277      values are not unique).
278    - [BUGFIX] Always set the idle alarm in IETF connection so that it
279      can time out.
280    - Use ls-qpack v0.10.6, as it silences some warnings.
281
2822019-10-21
283    - 2.4.8
284    - [OPTIMIZATION, BUGFIX] Use ls-qpack v0.10.5.
285
2862019-10-15
287    - 2.4.7
288    - Add echo client and server to the distibution.
289    - Add MD5 client and server to the distibution.
290    - Fix http_client: check command-line arguments better, prevent crash.
291    - Fix IETF conn: can_write_ack() should only care about APP PNS.
292    - Client: delay stream creation until handshake succeds.
293    - Reset HTTP stream whose write end is closed prematurely.
294    - Fix tickable(): mirror behavior of tick() wrt buffered packets.
295    - Log reason why engine is tickable.
296
2972019-10-11
298    - 2.4.6
299    - Minor code cleanup and logging improvements.
300    - Server and client programs: include library version (e.g. 2.4.6)
301      into `server' and `user-agent' headers.
302
3032019-10-08
304    - 2.4.5
305    - [OPTIMIZATION]: flush encoder stream only when necessary.
306    - [BUGFIX] Use ls-qpack v0.10.2 for new API -- and for a bug fix.
307    - [BUGFIX] Typo in IETF conn SETTINGS writer.
308    - Use latest BoringSSL.
309
3102019-10-08
311    - 2.4.4
312    - [API] Add lsquic_alpn2ver() to aid parsing Alt-Svc header.
313    - [BUGFIX] NULL dereference when H3 frame header would be split.
314    - [BUGFIX] Do not close fixed-size H3 frame prematurely.
315    - [BUGFIX] Allow PING frames in IETF mini conn.
316    - [BUGFIX] Mini conns: don't send any packets after receiving
317      CONNECTION_CLOSE.
318    - [BUGFIX] Client migration: reserve slot for DCID from transport params.
319    - [BUGFIX] Allow max_early_data_size=0 -- early_data might not be there.
320    - [BUGFIX] Use an invalid stream number to reset BPT cache (zero is now a
321      valid stream number).
322    - [SPEC] Use FINAL_SIZE_ERROR when FIN mismatch is detected.
323    - [OPTIMIZATION] Closed connection only gets one chance to send packets.
324    - [OPTIMIZATION] Flush headers stream before packetizing stream data.
325    - [OPTIMIZATION] process QPACK encoder STREAM frames immediately.
326    - Update ls-qpack to v0.10.1.
327
3282019-09-30
329    - 2.4.3
330    - Add GQUIC versions to the list of h3 ALPNs for Alt-Svc header.
331      For example, h3-Q043.  Chrome will switch to using this format at
332      some point in the future.
333    - [BUGFIX] Send correct value in max_streams_uni transport param
334    - [SPEC] Abort IETF QUIC connection if max_early_data_size is not set
335      to 0xFFFFFFFF
336
3372019-09-23
338    - 2.4.2
339    - [BUGFIX] H3 framing: fix zero-byte write when space is available
340    - [BUGFIX] Don't send STREAM frame when incoming unidirectgional stream
341      is closed
342    - [BUGFIX] Cancel all pending writes by stream reset by a GOAWAY
343    - [BUGFIX] Fix use-after-free in IETF full conn
344    - [OPTIMIZATION] Wait for session tickets for two seconds and then drop
345      SSL object and crypto streams.
346
3472019-09-18
348    - 2.4.0
349    - [FEATURE] QUIC and HTTP/3 Internet Draft 23 support
350
3512019-09-13
352    - 2.3.1
353    - [BUGFIX] Fix memory leaks
354    - [BUGFIX] Fix unit tests
355
3562019-09-12
357    - 2.3.0
358    - [FEATURE] BBR congestion control is on by default
359    - [BUGFIX] BBR app-limited logic
360    - [BUGFIX] Fix uninitialized warnings in IETF
361    - [BUGFIX] Update ls-qpack to v0.9.14
362    - [CLEANUP] Code cleanup
363
3642019-09-11
365    - 2.2.0
366    - [FEATURE] Server code is included in the library
367    - [FEATURE] IETF QUIC and HTTP/3 Support (ID-22)
368
3692019-05-13
370    - 1.21.2
371    - [OPTIMIZATION] HPACK: use history to improve compression performance
372
3732019-05-06
374    - 1.21.1
375    - [BUGFIX] If FIN or RST not received, don't delay stream destruction.
376    - [OPTIMIZATION] Speed up HPACK encoder by using same hash value to
377      search static and dynamic tables.
378
3792019-04-12
380    - 1.21.0
381    - [FEATURE] Add qlog log module.
382
3832019-04-01
384    - 1.20.0
385    - [FEATURE] Add support for Q046.
386
3872019-03-19
388    - 1.19.6
389    - [BUGFIX] Ensure that Largest Observed does not decrease in ACKs we
390      send.  ACK frames placed in packets in buffered queues (optimization
391      introduced in 1.17.15) can be preceded by an ACK frame generated later.
392      In this case, the older ACK frame should not be sent out, as Chromium-
393      based servers flags decrease in the ACK frame's Largest Observed value
394      as an error.
395
3962019-03-05
397    - 1.19.5
398    - [BUGFIX] Use correct public key from PUBS based on KEXS index.
399    - [BUGFIX] Check flags before dispatching writes, avoiding assert.
400    - [BUGFIX] Set :scheme to "https" (instead of "HTTP").
401
4022019-02-25
403    - 1.19.4
404    - [BUGFIX] Check buffer bounds when looking up version in 0-RTT blob.
405    - [BUGFIX] http_client: don't fetch 0-rtt info if handshake failed.
406    - Log number of pacer calls at DEBUG, rather than NOTICE, level.
407
4082019-02-18
409    - 1.19.3
410    - [BUGFIX] Q044: don't encode packet number in 6 bytes.  Six-byte
411      packet number encoding does not exist in Q044.  This fixes a
412      regression introduced in '[BUGFIX] Buffered packets can contain
413      ACK frames' -- we need to keep QUIC version in mind when selecting
414      the longest possible packet number encoding used for the buffered
415      packet that carries the ACK.
416    - [BUGFIX] Do not increase CWND when timeout occurs.
417    - http_client: support setting handshake timeout on command line.
418      Use -o handshake_to=timeout.
419    - http_client: use -k to connect UDP socket to pick up ICMP errors.
420    - http_client: allow pathless mode, when only handshake is performed
421      without issuing any requests.  This can be done by simply not
422      specifying a -p flag on the command line.
423
4242019-02-11
425    - 1.19.2
426    - [BUGFIX] Begin negotiation with version provided in 0-RTT info.
427    - [BUGFIX] Version checking in zero_rtt deserialize function.
428
4292019-02-04
430    - 1.19.1
431    - [BUGFIX] Fix Windows build.
432
4332019-02-04
434    - 1.19.0
435    - [FEATURE, API Change] 0-RTT support.  Add function to export 0-RTT
436      information; it can be supplied to a subsequent connect() call.
437    - [FEATURE] Add -0 flag to http_client to exercise 0-RTT support.
438    - [BUGFIX] Resuscitate the Windows build.
439    - [BUGFIX] Send HTTP settings (max header list size) if necessary.
440    - [BUGFIX] Buffered packets can contain ACK frames.
441    - [BUGFIX] Make packet writeable once all STREAM frames are elided.
442    - [BUGFIX] Fix potential null dereference when realloc fails.
443    - cmake: simplify build configuration.
444
4452019-01-28
446    - 1.18.0
447    - [API Change] Can specify clock granularity in engine settings.
448    - [BUGFIX] Pacer uses fixed clock granularity.  Since the change on
449      2018-04-09, it is not necessary to try to approximate the next tick
450      time in the pacer: it can use fix clock granularity specified by
451      the user.
452    - [BUGFIX] Do not tick constantly before handshake is done.
453    - [BUGFIX] Do not exit tick prematurely: reuse packet with ACK.  Even
454      if we cannot allocate *more* packets, we could still be able to write
455      to one already allocated.
456    - [BUGFIX] Do not schedule pacer if there are no lost packets.
457
4582019-01-17
459    - 1.17.15
460    - [BUGFIX] http_client: make sure only one read per on_read() callback
461      is performed in the header conversion bypass (-B) mode.
462    - http_client: with -E, assign random priority when stream is created.
463    - [OPTIMIZATION] On immediate write, place an ACK frame into the first
464      buffered packet if an ACK is queued.  This reduces the number of
465      standalone ACK packets.
466    - [OPTIMIZATION] Allow placing more than one STREAM frame from the same
467      stream into an outgoing packet.  This change minimizes the number of
468      buffered packets required to store several small HTTP messages by
469      virtue of allowing more than one STREAM frame from HEADERS stream in
470      the same packet.
471    - [OPTIMIZATION] Flush headers when writing to buffered packets.  This
472      causes the headers to be written to the same buffered packet queue,
473      thereby improving packet utilization, especially for small HTTP
474      messages.
475
4762019-01-16
477    - 1.17.14
478    - [FEATURE] http_client can now collect stats: time to connect, TTFB,
479      time to download, requests per seconds, and bandwidth.  See -t flag.
480    - [BUGFIX] http_client: -B, -K, and -r can be used at the same time.
481    - [BUGFIX] http_client: do not display cert chain before each request.
482      Now this is only done once per connection, if the handshake is
483      successful and -a option is given.
484    - [BUGFIX] Do not wait to dispatch on_close() after reading.  If a
485      stream is scheduled to be closed after on_read() callback returns,
486      close it immediately instead of waiting until the end of the tick.
487      If client creates new request from on_close() event, they will be
488      processed in the same tick instead of waiting for the next one.
489    - [BUGFIX] HEADERS stream is critical: always treat it with highest
490      priority.
491
4922019-01-10
493    - 1.17.12
494    - [FEATURE] http_client can now issue parallel requests in the context
495      of a single connection.  See -w option.
496
4972019-01-03
498    - 1.17.11
499    - Fix strict aliasing warning in optimized compilation.
500
5012018-12-27
502    - 1.17.10
503    - Fix the example program to be able to use parallel connections
504      again.  (See the -n argument.)
505
5062018-12-18
507    - 1.17.9
508    - [BUGFIX] Engine: reduce minimum batch size from 256 to 4
509
5102018-12-10
511    - 1.17.8
512    - [BUGFIX] Fix compilation on FreeBSD and 32-bit Linux
513
5142018-12-03
515    - 1.17.7
516    - [BUGFIX] Do not unset PING alarm before ringing expired alarms.
517      This prevented PING from ever being sent.
518
5192018-11-29
520    - 1.17.6
521    - Add failsafe: resume sending packets after some time
522
523      The change puts a 1-second limit on the amount of time the engine
524      will not send packets after some packets are delayed.  This makes
525      the library robust in case the user does not unblock the engine
526      explicitly using lsquic_engine_send_unsent_packets() call.
527
528    - [BUGFIX] Handle corner cases in send controller when packets are
529      a) delayed or b) dropped during repackaging.
530    - [BUGFIX] Memory leak: destroy buffered packets during controller
531      cleanup.
532
5332018-11-16
534    - 1.17.3
535    - [BUGFIX] Do not send STOP_WAITING frames when using Q044
536
5372018-10-19
538    - 1.17.2
539    - [BUGFIX] Memory leak in test_frame_rw unit test.
540    - [BUGFIX] Parsing packets with short IETF header: do not overwrite
541      flags.  (Only a problem in unit tests -- benign otherwise.)
542
5432018-10-16
544    - 1.17.0
545    - [API Change] Packet out Memory Interface (PMI) update:
546      - Split PMI pool return into pmi_release and pmi_return
547      - PMI callbacks take peer_ctx and is_ipv6 arguments
548    - [BUGFIX] Fix use-after-free when certificate is updated
549    - Silence gcc warning in optimized mode by performing useless
550      initialization
551    - cmake: use the standard variable CMAKE_BUILD_TYPE instead of
552      DEVEL_MODE
553
5542018-10-03
555    - 1.16.0
556    - [API Change] Add lsquic_conn_n_avail_streams()
557    - [BUGFIX] only dispatch crypto stream read events if WANT_READ is on
558
5592018-09-27
560    - 1.15.0
561    - [API Change] Add LSCONN_ST_PEER_GOING_AWAY to the list of conn statuses
562    - [BUGFIX] free uncompressed headers correctly when error occurs
563
5642018-09-12
565    - 1.14.3
566    - [BUGFIX] Do not abort conn on STREAM frame for a reset stream
567    - [BUGFIX] Drop packets that would become empty due to repackaging.
568      Packets on the scheduled queue may be marked for repackaging.
569      Frames such as ACK frame that are never resent are removed from
570      repackaged packets.  We must check that the newly repackaged packet
571      would not be empty.  If it would be, it is destroyed instead and
572      the next packet on the scheduled queue is used.  Note that this
573      change only affects the logic to return the next packet to be sent.
574      Lost packets that are being rescheduled are already processed in
575      this fashion.
576    - Byteswap CID before logging it - this makes it match Chrome CIDs.
577      (Except Q035, which is the last little-endian GQUIC version we
578      support.)
579
5802018-09-06
581    - 1.14.0
582    - [API Change] Disable packet sending if full batch cannot be sent
583      If lsquic_packets_out_f() cannot send the whole batch, disable
584      packet sending until lsquic_engine_send_unsent_packets() is called.
585    - [BUGFIX] Handle case when STREAM frame does not fit.
586    - [BUGFIX] Always allow incoming STREAM frames to overlap.  Peers
587      may send overlapping STREAM frames even if using versions older
588      than Q043.
589    - Custom header set fixes:
590      - set "FIN reached" flag when custom header with FIN flag is
591        claimed;
592      - do not return custom header set for a reset stream.
593
5942018-08-27
595
596    - 1.13.0
597    - [FEATURE, API Change] Add ability to create custom header set
598      objects via callbacks.  This avoids reading and re-parsing
599      headers from the stream.
600
6012018-08-27
602
603    - 1.12.4
604    - Fix memory leak when engine is destroyed
605    - Fix memory leak in http_client
606    - Fix gcc warning in unit tests
607
6082018-08-22
609
610    - 1.12.3
611    - [BUGFIX] Fix duplicate STREAM frame detection
612
6132018-08-20
614
615    - 1.12.2
616    - [BUGFIX] Update count of scheduled bytes when adjusting size of
617      an already-scheduled packet.
618    - Emit info instead of warning messages when stream is used in
619      unexpected ways.
620
6212018-08-17
622
623    - 1.12.0
624    - [FEATURE, API Change] Add support for certificate verification
625
6262018-08-16
627
628    - 1.11.1
629    - [BUGFIX] Fix STOP_WAITING frame processing in the new Q044 code
630
6312018-08-15
632
633    - 1.11.0
634    - [FEATURE] Add support for Q044.
635
6362018-08-09
637
638    - 1.10.2
639    - [BUGFIX] Don't go over limit when creating delayed streams
640
6412018-07-10
642
643    - 1.10.1
644    - [BUGFIX]  process connections after each batch of packets is read
645      This avoids a problem of accumulating a very large list of packets
646      (possible when speeds are high and socket's receive buffer is large)
647      and processing it all at once.
648    - If glibc is older than 2.17, link with rt.  This is necessary for
649      clock_getres(2).
650    - Add version macros to lsquic.h; remove unnecessary includes.
651
6522018-06-13
653
654    - [BUGFIX] allow multiple parallel connections by default
655
656      Use the original method of tracking connections by CIDs by default.
657      If zero-sized CID support is turned on, connections are tracked by
658      the address.  A new connection is not created if another connection
659      is using the same network address
660
6612018-05-30
662
663    - [FEATURE, API CHANGE] Support zero-sized CIDs in received packets
664
6652018-05-24
666
667    - Close connection properly when packet encryption fails
668
6692018-05-23
670
671    - [BUGFIX] Do not produce packet sequence gaps due to delayed packets
672
6732018-05-21
674
675    - [API Change] Add optional callback to call when handshake is done
676    - [API Change, BUGFIX] After send failure, wait until transport available
677
6782018-05-18
679
680    - [API] Expose useful lsquic_ver2str[] in lsquic.h
681    - [BUGFIX] Do not produce packet sequence gaps due to STREAM frame elision
682    - Improve checks of number of incoming streams limit and associated
683      error reporting.
684    - [BUGFIX] Command-line option `-6` now works correctly.
685
6862018-05-16
687
688    - [FEATURE] DNS resolution
689    - [BUGFIX] Frame insertion mis-ID as overlap instead of dup
690    - http_client: fix priority range generated by -E flag
691
6922018-05-09
693
694    - [FEATURE] Add support for Q043.
695    - Support for versions Q037, Q038, Q041, and Q042 has been removed.
696    - Fix typo in debug message.
697    - Fix code indentation.
698    - Add /* fallthru */ comment to stop newer gcc from complaining.
699    - Logger: fix compilation of optimized Windows build.
700
7012018-05-04
702
703    - [FEATURE] Add support for Q042.
704    - Remove comment: MSPC is obsolete (no code changes)
705    - Prog: use lsquic_str2ver() when processing -o version flag
706    - Remove unused CTIM and SRBF transport parameters
707    - Disable QUIC versions Q037 and Q038 by default
708    - Fix Windows compilation by including compat header file in
709      lshpack.c
710    - Address warnings produced by newer versions of gcc
711    - Future-proof: turn off -Werror
712
7132018-05-02
714
715    - [BUGFIX] Make lsquic_conn_quic_version() available
716    - Switch to using ls-hpack 1.1
717    - [BUGFIX] Do not ignore stream resets after receiving FIN
718
7192018-04-27
720
721    - HPACK: do not allow header block to end with table size update.
722
7232018-04-25
724
725    - [BUGFIX] Do not create gap in sent packnos when squeezing delayed
726      packets.
727    - [BUGFIX] sendctl checks for all unacked bytes, not just retx bytes.
728    - [BUGFIX] connections with blocked scheduled packets are not tickable
729      for sending.
730    - [BUGFIX] Conn is tickable if it wants to send a connection-level
731      frame.
732
7332018-04-23
734
735    - Fix busy loop: tickable must make progress.  When connection is
736      self-reporting as tickable, it must make progress when ticked.  There
737      are two issues:
738        1. If there are buffered packets, the connection is only tickable if
739           they can be sent out.
740        2. A connection is tickable if there are streams on the servicing
741           queue.  When the tick occurs, we must service the stream
742           independent of whether any packets are sent.
743    - Fix assertion in pacer which can be incorrect under some
744      conditions.
745    - cmake: do not turn on address sanitizer if in Travis.
746
7472018-04-20
748
749    - [BUGFIX] Fix bug in lsquic_engine_connect() exposed by yesterday's
750      changes.
751
7522018-04-19
753
754    - [BUGFIX] Add connection to Tickable Queue on stream write
755    - cmake: use MSVC variable instead of trying to detect
756    - engine: improve connection incref/decref logging
757    - stream: don't ignore errors that may occur on triggered flush
758    - connection: remove obsolete method
759    - engine: indicate connection as tickable if previous call went
760      over threshold
761
7622018-04-09
763
764    [API Change, OPTIMIZATION] Only process conns that need to be processed
765
766    The API is simplified: do not expose the user code to several
767    queues.  A "connection queue" is now an internal concept.
768    The user processes connections using the single function
769    lsquic_engine_process_conns().  When this function is called,
770    only those connections are processed that need to be processed.
771    A connection needs to be processed when:
772
773        1. New incoming packets have been fed to the connection.
774        2. User wants to read from a stream that is readable.
775        3. User wants to write to a stream that is writeable.
776        4. There are buffered packets that can be sent out.  (This
777           means that the user wrote to a stream outside of the
778           lsquic library callback.)
779        5. A control frame (such as BLOCKED) needs to be sent out.
780        6. A stream needs to be serviced or delayed stream needs to
781           be created.
782        7. An alarm rings.
783        8. Pacer timer expires.
784
785    To achieve this, the library places the connections into two
786    priority queues (min heaps):
787
788        1. Tickable Queue; and
789        2. Advisory Tick Time queue (ATTQ).
790
791    Each time lsquic_engine_process_conns() is called, the Tickable
792    Queue is emptied.  After the connections have been ticked, they are
793    queried again: if a connection is not being closed, it is placed
794    either in the Tickable Queue if it is ready to be ticked again or
795    it is placed in the Advisory Tick Time Queue.  It is assumed that
796    a connection always has at least one timer set (the idle alarm).
797
798    The connections in the Tickable Queue are arranged in the least
799    recently ticked order.  This lets connections that have been quiet
800    longer to get their packets scheduled first.
801
802    This change means that the library no longer needs to be ticked
803    periodically.  The user code can query the library when is the
804    next tick event and schedule it exactly.  When connections are
805    processed, only the tickable connections are processed, not *all*
806    the connections.  When there are no tick events, it means that no
807    timer event is necessary -- only the file descriptor READ event
808    is active.
809
810    The following are improvements and simplifications that have
811    been triggered:
812
813        - Queue of connections with incoming packets is gone.
814        - "Pending Read/Write Events" Queue is gone (along with its
815          history and progress checks).  This queue has become the
816          Tickable Queue.
817        - The connection hash no longer needs to track the connection
818          insertion order.
819
8202018-04-02
821
822    - [FEATURE] Windows support
823
824    - Reduce stack use -- outgoing packet batch is now allocated on the heap.
825
8262018-03-09
827
828    - [OPTIMIZATION] Merge series of ACKs if possible
829
830      Parsed single-range ACK frames (that is the majority of frames) are
831      saved in the connection and their processing is deferred until the
832      connection is ticked.  If several ACKs come in a series between
833      adjacent ticks, we check whether the latest ACK is a strict superset
834      of the saved ACK.  If it is, the older ACK is not processed.
835
836      If ACK frames can be merged, they are merged and only one of them is
837      either processed or saved.
838
839    - [OPTIMIZATION] Speed up ACK verification by simplifying send history.
840
841      Never generate a gap in the sent packet number sequence.  This reduces
842      the send history to a single number instead of potentially a series of
843      packet ranges and thereby speeds up ACK verification.
844
845      By default, detecting a gap in the send history is not fatal: only a
846      single warning is generated per connection.  The connection can continue
847      to operate even if the ACK verification code is not able to detect some
848      inconsistencies.
849
850    - [OPTIMIZATION] Rearrange the lsquic_send_ctl struct
851
852      The first part of struct lsquic_send_ctl now consists of members that
853      are used in lsquic_send_ctl_got_ack() (in the absense of packet loss,
854      which is the normal case).  To speed up reads and writes, we no longer
855      try to save space by using 8- and 16-bit integers.  Use regular integer
856      width for everything.
857
858    - [OPTIMIZATION] Cache size of sent packet.
859
860    - [OPTIMIZATION] Keep track of the largest ACKed in packet_out
861
862      Instead of parsing our own ACK frames when packet has been acked,
863      use the value saved in the packet_out structure when the ACK frame
864      was generated.
865
866    - [OPTIMIZATION] Take RTT sampling conditional out of ACK loop
867
868    - [OPTIMIZATION] ACK processing: only call clock_gettime() if needed
869
870    - [OPTIMIZATION] Several code-level optimizations to ACK processing.
871
872    - Fix: http_client: fix -I flag; switch assert() to abort()
873
8742018-02-26
875    - [API Change] lsquic_engine_connect() returns pointer to the connection
876      object.
877    - [API Change] Add lsquic_conn_get_engine() to get engine object from
878      connection object.
879    - [API Change] Add lsquic_conn_status() to query connection status.
880    - [API Change] Add add lsquic_conn_set_ctx().
881    - [API Change] Add new timestamp format, e.g. 2017-03-21 13:43:46.671345
882    - [OPTIMIZATION] Process handshake STREAM frames as soon as packet
883      arrives.
884    - [OPTIMIZATION] Do not compile expensive send controller sanity check
885      by default.
886    - [OPTIMIZATION] Add fast path to gquic_be_gen_reg_pkt_header.
887    - [OPTIMIZATION] Only make squeeze function call if necessary.
888    - [OPTIMIZATION] Speed up Q039 ACK frame parsing.
889    - [OPTIMIZATION] Fit most used elements of packet_out into first 64 bytes.
890    - [OPTIMIZATION] Keep track of scheduled bytes instead of calculating.
891    - [OPTIMIZATION] Prefetch next unacked packet when processing ACK.
892    - [OPTIMIZATION] Leverage fact that ACK ranges and unacked list are.
893      ordered.
894    - [OPTIMIZATION] Reduce function pointer use for STREAM frame generation
895    - Fix: reset incoming streams that arrive after we send GOAWAY.
896    - Fix: delay client on_new_conn() call until connection is fully set up.
897    - Fixes to buffered packets logic: splitting, STREAM frame elision.
898    - Fix: do not dispatch on_write callback if no packets are available.
899    - Fix WINDOW_UPDATE send and resend logic.
900    - Fix STREAM frame extension code.
901    - Fix: Drop unflushed data when stream is reset.
902    - Switch to tracking CWND using bytes rather than packets.
903    - Fix TCP friendly adjustment in cubic.
904    - Fix: do not generate invalid STOP_WAITING frames during high packet
905      loss.
906    - Pacer fixes.
907
9082017-12-18
909
910    - Fix: better follow cubic curve after idle period
911    - Fix: add missing parts to outgoing packet splitting code
912    - Fix: compilation using gcc 4.8.4
913
9142017-10-31
915
916    - Add APIs.txt -- describes LSQUIC APIs
917
9182017-10-31
919
920    - [API Change] Sendfile-like functionality is gone.  The stream no
921      longer opens files and deals with file descriptors.  (Among other
922      things, this makes the code more portable.)  Three writing functions
923      are provided:
924
925        lsquic_stream_write
926        lsquic_stream_writev
927        lsquic_stream_writef    (NEW)
928
929      lsquic_stream_writef() is given an abstract reader that has function
930      pointers for size() and read() functions which the user can implement.
931      This is the most flexible way.  lsquic_stream_write() and
932      lsquic_stream_writev() are now both implemented as wrappers around
933      lsquic_stream_writef().
934
935    - [OPTIMIZATION] When writing to stream, be it within or without the
936      on_write() callback, place data directly into packet buffer,
937      bypassing auxiliary data structures.  This reduces amount of memory
938      required, for the amount of data that can be written is limited
939      by the congestion window.
940
941      To support writes outside the on_write() callback, we keep N
942      outgoing packet buffers per connection which can be written to
943      by any stream.  One half of these are reserved for the highest
944      priority stream(s), the other half for all other streams.  This way,
945      low-priority streams cannot write instead of high-priority streams
946      and, on the other hand, low-priority streams get a chance to send
947      their packets out.
948
949      The algorithm is as follows:
950
951      - When user writes to stream outside of the callback:
952        - If this is the highest priority stream, place it onto the
953          reserved N/2 queue or fail.
954            (The actual size of this queue is dynamic -- MAX(N/2, CWND) --
955             rather than N/2, allowing high-priority streams to write as
956             much as can be sent.)
957        - If the stream is not the highest priority, try to place the
958          data onto the reserved N/2 queue or fail.
959      - When tick occurs *and* more packets can be scheduled:
960        - Transfer packets from the high N/2 queue to the scheduled
961          queue.
962        - If more scheduling is allowed:
963          - Call on_write callbacks for highest-priority streams,
964            placing resulting packets directly onto the scheduled queue.
965        - If more scheduling is allowed:
966          - Transfer packets from the low N/2 queue to the scheduled
967            queue.
968        - If more scheduling is allowed:
969          - Call on_write callbacks for non-highest-priority streams,
970            placing resulting packets directly onto the scheduled queue
971
972      The number N is currently 20, but it could be varied based on
973      resource usage.
974
975    - If stream is created due to incoming headers, make headers readable
976      from on_new.
977
978    - Outgoing packets are no longer marked non-writeable to prevent placing
979      more than one STREAM frame from the same stream into a single packet.
980      This property is maintained via code flow and an explicit check.
981      Packets for stream data are allocated using a special function.
982
983    - STREAM frame elision is cheaper, as we only perform it if a reset
984      stream has outgoing packets referencing it.
985
986    - lsquic_packet_out_t is smaller, as stream_rec elements are now
987      inside a union.
988
9892017-10-12
990
991    - Do not send RST_STREAM when stream is closed for reading
992    - Raise maximum header size from 4K to 64K
993    - Check header name and value lengths against maximum imposed by HPACK
994    - Fix NULL dereference in stream flow controller
995
9962017-10-09
997
998    - Hide handshake implementation behind a set of function pointers
999    - Use monotonically increasing clock
1000    - Make sure that retx delay is not larger than the max of 60 seconds
1001
10022017-09-29
1003
1004    - A few fixes to code and README
1005
10062017-09-28
1007
1008    - Add support for Q041; drop support for Q040
1009
10102017-09-27
1011
1012    - Fix CMakeLists.txt: BoringSSL include and lib was mixed up
1013
10142017-09-26
1015
1016    - Add support for Mac OS
1017    - Add support for Raspberry Pi
1018    - Fix BoringSSL compilation: include <openssl/hmac.h> explicitly
1019
10202017-09-22
1021
1022    - Initial release
1023