Release 3.1.0

Release 3.0.0

Release 2.30.1

Release 2.29.6

- Documentation: describe lsquic internals ("guts").
- Two more fixes to compliance issues found by h3spec.
- Truncate, don't abort, SCIDs larger than 16 bytes (PR #244).
- Several small internal improvements and space optimizations.

Release 2.29.3

- [BUGFIX] Do not send RESET_STREAM if writing to stream is already
finished.
- perf_client: wait for all ACKs before exiting.
- Improve how generated RESET_STREAM is logged.
- Fix compilation in different combos of adv_tick/conn_stats flags.
- Move qpack warning disablement into src/liblsquic/CMakeLists.txt.

Release 2.29.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 34 support and v1 support.
The latter is turned off by default.
- Drop support for ID-28 and ID-32.
- [BUGFIX] IETF QUIC mini conn receive history (trechist): allow
unlimited inserts by dropping smallest elements.
- [BUGFIX] gQUIC: set STTL to correct value, issue #226.
- [BUGFIX] Account for poison packet gap when MTU probe was too large.

Release 2.28.0

- [API] lsquic_ssl_sess_to_resume_info() is the new way to get
session info.
- [API] Add user pointer to ea_generate_scid callback.
- [API] Add lsquic_dcid_from_packet() -- a fast function to parse
out DCID.
- [API] Add es_max_batch_size to control outgoing packet batch size.
- [BUGFIX] Disallow sending of header while promise is being written.
- [BUGFIX] Flush stream when buffered bytes exhaust stream cap.
- [BUGFIX] Deactivate HQ frame if writing push promise fails.
- Perform sanity check on peer transport parameters and fail the
handshake if some flow control limits are too low. This can be
turned off, see es_check_tp_sanity.
- http_server: fix how requests are read in "hq" mode.

Release 2.27.1

- [API] New knob to set outgoing packet batch size.
- Aborted connection now become tickable immediately.
- Abort connection when HTTP/3 frame cannot be opened (can only happen
when malloc fails).

Release 2.27.0

- [API] Remove keylog callbacks. See issue #188.
- Add a bit more ALPN logging.

Release 2.25.0

- [API, FEATURE] Add es_delay_onclose option to delay on_close until all
data is ACKed. Use new function lsquic_stream_has_unacked_data() to
learn whether peer acknowledged all data written to stream.
- [API] Add optional on_reset() stream callback to get notifications
when RESET or STOP_SENDING frames are received.
- [BUGFIX] On STOP_SENDING, make conn tickable is _writeable_, not
readable.

Release 2.24.5

- [FEATURE] Improve Delayed ACKs extension and turn it on by default.
- Limit receive history to a finite amount of memory.

Release 2.24.4

- [BUGFIX] Check whether ECN counts are set in ACK struct before using them.
- [BUGFIX] Calculate TLP timer correctly when only one packet is in flight.
- [BUGFIX] Min RTO delay is 200 milliseconds, not 1 second.
- [BUGFIX] Memory leak in QPACK decoder handler: discard hset when necessary.
- Allow retired and drained CIDs to be reused after a timeout.

Release 2.24.2

- [BUGFIX] Allow peer to migrate when its SCID is zero-length.
- [BUGFIX] PADDING size calculation: only one Short packet can be
coalesced. (This should have been part of the fix in 2.24.1).
- Abort connect if received NEW_CONNECTION_ID but current DCID is
zero-length.
- Improve log messages

Support get_ssl_ctx callback for client

Release 2.23.2

- Add QPACK stats collection and experimentation mode, see the new
es_qpack_experiment setting.
- Log busy connection stats every second using the new "conn-stats"
log module.
- Log about skipping only once.
- Update HTTP/3 greased frame type formula.
- Use ls-qpack v2.2.1.

Release 2.23.0

- [FEATURE] IETF Client 0-RTT support.
- [BUGFIX] Do not schedule MTU probe on first tick.
- [BUGFIX] Parsing DATAGRAM frame.
- [BUGFIX] If push promise fails, do not invoke hset destructor.
- [BUGFIX] Client: When connections are IDed by port number, check DCID.
Fixes issue #176.
- Revert the 2.22.1 lsquic_is_valid_hs_packet change. All that was
necessary is a change to the way we call it in lsquic_engine. No
change to the function itself is required.

Release 2.22.0

- [FEATURE] Extensible HTTP Priorities (HTTP/3 only).
- [FEATURE] Add conn context to packet-out memory interface (PR #175).
- [BUGFIX] gQUIC proof generation: allocate buffer big enough for
signature (issue #173).
- [BUGFIX] Make library thread-safe: drop use of global variables
(issue #133, issue #167).
- [BUGFIX] Deactivate only *recent* HQ frame, not any HQ frame.
- [BUGFIX] gQUIC server: associate compressed cert with SSL_CTX,
instead of keeping them in a separate hash, potentially leading
to mismatches.
- [BUGFIX] Stream data discard infinite loop: break on FIN.
- cmake: add install target via -DCMAKE_INSTALL_PREFIX (PR #171).
- Support randomized packet number to begin a connection.
- Mini and full IETF connection size optimization.
- http_client: specify HTTP priorities based on stream conditions.

GSO-Friendly Packet Memory (#175)

Fix several thread safety issues

Fixes bug #128 and bug #167.

Release 2.21.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 31 support.
- [API] Let user generate Souce Connection IDs.
- [FEATURE] Allow building lsquic as shared library.
- [OPTIMIZATION] Receive history: use a single contiguous memory
block for everything.
- Deprecate QUIC versions ID-27 and ID-30.

Connection ID Steering (#165)

Release 2.20.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 30 support.
- [FEATURE] Unreliable Datagram Extension support.
- [FEATURE] Adaptive congestion controller.
- [BUGFIX] Do not send MAX_STREAM_DATA frames on crypto streams.
- [BUGFIX] Fail with CRYPTO_BUFFER_EXCEEDED when too much CRYPTO
data comes in.
- [BUFFIX] Spin bit is now strictly per path; value is reset on
DCID change.
- [BUGFIX] Check that max value of max_streams_uni and
max_streams_bidi TPs is 2^60.
- [BUGFIX] Close IETF mini conn immediately if crypto session
cannot be initialized.
- Deprecate ID-28 (no browser uses it): it's no longer in the
default versions list.
- New programs duck_server and duck_client that implement the
experimental siduck-00 protocol. They quack!
- IETF crypto streams: don't limit ourselves from sending.
- Command-line programs: turn off QL loss bits if -G is used, as
Wireshark cannot decrypt QUIC packets when this extension is used.
- Turn all h3 framing unit tests back on.
- Fix malo initialization when compiled in no-pool mode.

Release 2.19.9

- [FEATURE] Add lsquic_stream_pwritev(). This function allows one to
reduce the number of system calls required to read a file from disk
by using lsquic_stream_pwritev() together with preadv(2).
- [BUGFIX] When stream is reset, it is writeable -- let user collect
the error.
- [BUGFIX] Calculate correct conn flow control if reading ends early.
- [BUGFIX] Remove stream from read and write queues on internal
shutdown. This is a regression introduced in 2.19.7.
- [BUGFIX] Swapped arguments in IETF RESET_FRAME generation.
- Turn off mini conn history when compiling with Visual Studio; this
allows the project to compile on Windows again.
- http_client: Add -3 flag to stop reading from streams early; code
cleanup.
- Don't use -Werror.

Release 2.19.4

- [BUGFIX] Do not return an oversize MTU probe to connection twice.
- [FEATURE] Delayed Acks updated to latest draft. Still experimental.
- Minor code cleanup in IETF full connection.

Release 2.19.0

- [FEATURE] DPLPMTUD support. IETF connections now search for the
maximum packet size, improving throughput.
- [DEBUG] Record event in stream history when on_close() is called
in dtor.

Release 2.18.1

- [FEATURE] Implement the "QUIC bit grease" extension.
- [BUGFIX] Selecting CID used for logging on client.
- [BUGFIX] Header protection assertion.
- [BUGFIX] Server: enable SSL key logging when cert lookup callback
is not set.
- Remove some dead code.

Release 2.18.0

- [API] Rename "0-RTT" to "session resumption." In IETF QUIC, "0-RTT"
always refers to early data, meaning a request that the server can
reply to in the very first return flight. A more appropriate name
for what we support on the client site is "session resumption," which
is standard TLS terminology. Later, when we add support for 0-RTT
(early data), we can use the 0-RTT terminology again, this time in
proper context.
- [BUGFIX] Do not set certificate callback if ea_lookup_cert is NULL.
- [BUGFIX] Make connection tickable when it's marked as closed.
- [BUGFIX] Fail certificate lookup if SNI is not present in HTTP mode.
- Several documentation fixes and improvements.
- Minor code cleanup.

Release 2.17.2

- [BUGFIX] Infinite loop in stream: advance read offset when discarding data.
- [OPTIMIZATION] Header protection: only initialize cipher once.
- [OPTIMIZATION] Batch header protection application.

Release 2.17.1: fix regression in 2.17.0

Release 2.17.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 29 support.
- [BUGFIX] Check that scheduled packets are also sendable when
calculating a connection's "tickable" property.
- [BUGFIX] Don't count scheduled packets as in-flight when pacer is
checked on tick.
- gQUIC: delay calling on_new for pushed stream until headers are
available.
- Allow nested calls to lsquic_engine_connect().

Release 2.16.2

- [BUGFIX] ID-28: do not use TLS middlebox compatibility mode in
ClientHello. This change requires using a newer version of BoringSSL.
- [BUGFIX] Free connections in Advisory Tick Time Queue in engine dtor.
- [BUGFIX] IETF QUIC client: narrow migration check to a single path.
- [BUGFIX] NULL dereference: set function pointers for alarm for path
challenges 2 and 3.
- [BUGFIX] HTTP/3 headers may be followed immediately by trailers.
- [BUGFIX] Log messages when SCID changes.

Release 2.16.1

- [FEATURE] Use "no-progress timeout" after which connection is closed.
- [BUGFIX] Select new SCID when current SCID is retired.
- [BUGFIX] Don't warn about dropped Initial packet sequence gaps during
mini/full handoff.
- [BUGFIX] Send correct conn error when HTTP/3 frame is truncated.
- [BUGFIX] Mini conn: consider amplification when deciding to return
TICK_SEND.
- [BUGFIX] Don't double-count tag length in amplification logic.
- [BUGFIX] Don't squeeze out lone path challenges.
- [BUGFIX] Log messages dealing with scheduled packet queue squeezing.
- [BUGFIX] don't wipe current path if no path challenge responses
come back.
- [BUGFIX] When path is reset, don't lose path_id which is used for
logging.
- Downgrade flow control violations to info log level from warnings.
- Fix connection cap extra check, avoid checks in nested calls.
- Fix some unit tests when extra checks are enabled.
- Use ls-hpack 2.2.1.
- Turn off unconditional extra checks for IETF clients.
- Extra checks: don't verify sent size of hello packets. Client
changes DCID length and this check will fail.

Fix Windows support

Release 2.15.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 28 support.
- [BUGFIX] Ignore Retry packets after other packets are decrypted
successfully.
- [BUGFIX] Transport parameter decoding: CID no longer has 4-byte
length minimum.
- http_client: fix and optimize lsxpack_header allocator.
- Drop support for Internet Draft 25.

Release 2.14.5

- [BUGFIX] In coalesced datagram, ignore packets whose CID does not match.
- [BUGFIX] Frame reader: skip headers if target stream is not found.
- [BUGFIX] Log message in QPACK decoder handler.

Release 2.14.1

- [BUGFIX] Place connections on tickable queue when sending is reenabled.
- [BUGFIX] A connection is tickable if it has unsent packets.
- [BUGFIX] Heed peer's max_packet_size transport parameter.

Release 2.13.0

- [API] Use lsxpack_header structure to process incoming headers.
- [BUGFIX] Fix assertion when zero-padding Initial packet.
- [BUGFIX] Use idle timeout before we learn of peer's value.
- Use ls-hpack 2.0.0 -- has lsxpack_header changes.
- Use ls-qpack 0.14.0 -- new, common with ls-hpack, XXH seed (not used yet).
- Code cleanup: prefix exported functions with "lsquic_".

Release 2.12.0

- [FEATURE] QUIC timestamps extension.
- [API] New: ea_alpn that is used when not in HTTP mode.
- [BUGFIX] SNI is mandatory only for HTTP/3 and gQUIC.
- [BUGFIX] Benign double-free -- issue #110.
- [BUGFIX] Printing of transport parameters.

API: add ea_alpn that is used when not in HTTP mode

Release 2.11.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 27 support.
- [FEATURE] Add experimental delayed ACKs extension.
- Drop support for Internet Draft 24.
- Code cleanup.

Add experimental support for delayed ACKs extension

Fail engine ctor if stream callbackes are not specified

Code cleanup. Improve comments in lsquic.h

Release 2.10.5

- [BUGFIX] BBR: call cci_sent() with correct arguments and at correct time.
- Refactor transport parameters module.
- Minor code cleanup.

Release 2.10.4

- [BUGFIX] Send HANDSHAKE_DONE only after Finished is received.
- [BUGFIX] Don't treat garbage UDP padding as library error; ignore
it instead.
- [BUGFIX] Fix compilation on FreeBSD (missing header).

Fix duplicate header includes

Release 2.10.3

- [BUGFIX] Cancel path responses and challenges on old path when
switching to new path.
- Logging network path information.

Release 2.10.1

- [BUGFIX] Coalesced packets could get longer than normal packet size.
- Add spin bit configuration option es_spin (-o spin=[01]).
- Disable spin bit in 1/16 of connections.
- Improve logging a bit.

Release 2.10.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 25 support.
- [API] Drop support for ID-23.
- [BUGFIX] Set key phase bit on outgoing packets correctly.
- Code cleanup.

Release 2.9.0

- [API] Drop support for Q039.
- Improve ACK-queuing logic. Send an ACK once in a while if
peer keeps on sending non-ack-eliciting packets.
- Improve Alt-Svc string: Q050 and later are not included in
the old-style "quic" string.
- Send stateless resets if connection could not be promoted.
- Schedule MAX_DATA if needed when DATA_BLOCKED is received.
- Use ls-qpack 0.11.2 -- needed for server push optimization.
- Code cleanup: handle some error cases, improve logging.

Release 2.8.9

- [BUGFIX] Use ls-qpack 0.11.1
- [OPTIMIZATION] Generate random bytes in batches.
- Change loss_bits transport parameter ID to 0x1057 following latest
draft.
- Randomize period with which PINGs are sent to elicit ACKs.
- Some refactoring and code cleanup.

Release 2.8.7

- [BUGFIX] Initial packet size check for IETF mini conn applies to
UDP payload, not QUIC packet.
- Support old and new school loss_bits transport parameter.
- Use Q run length of 64 as suggested in the loss bits Draft.
- Undo square wave count when packet is delayed.
- Code cleanup; minor fixes.

Release 2.8.1

- [FEATURE] Use occasional packet number gaps to detect optimistic
ACK attacks.
- [BUGFIX] Q050 client: all packet numbers are in the App PNS.
- [OPTIMIZATION] Merge multi-range ACK frames, not just single-range
ACK frames.
- IETF QUIC: use RTT estimate in ack timeout calculation.
- IETF handshake: abort conn when unexpected errors occur.
- Use PING rather than MAX_DATA frames to elicit ACKs from peer.
- Server: enforce 1200 byte Initial minimum packet size.
- [CLEANUP] Remove code to disable gQUIC crypto.
- [CLEANUP] Remove n_timestamps from ACK info struct.
- Optimize driver: reuse previous ancillary message when possible.

Release 2.8.0

- [FEATURE] Add support for Q050.
- [OPTIMIZATION] Reduce mallocs in gQUIC handshake.
- [BUGFIX] Disable redo of failed STREAM frame insertion with debug
logging.

Release 2.7.3

- [DEBUG] Further dedup next advisory tick messages when reason is
the same.
- [BUGFIX] Update size of `a` array in TP struct. Fixes (benign)
GitHub bug #94.
- Use Cubic by default again instead of BBR, as it delivers more
consistent performance.

Release 2.7.2

- [BUGFIX] Send controller: update scheduled bytes when DCID length
changes (IETF client).
- [BUGFIX] Drop alarm check from sanity test. It no longer works now
that we use loss chains.
- [PORTABILITY] Fix build on Alpine Linux.
- [PORTABILITY] Fix build using XCode.
- Client initial DCID length: use RAND_bytes() instead of rand(3).
- Add unit tests for connection min heap.
- [DEBUG] Log CID in gQUIC handshake module
- [DEBUG] Turn on extra checks for IETF client send controller.
- [DEBUG] Dedup next advisory tick messages when reason is IDLE timer.
- [DEBUG] QPACK decoder handler: log header error code.

Release 2.7.0

- [API, FEATURE] Close connection immediately when ea_packets_out()
fails with errno != EAGAIN. The API change is that errno is now
examined. Make sure to set it if using something other than
sendmsg() to send packets.
- [CLEANUP] Immediate close logic in IETF full conn.
- [CLEANUP] Fix bogus warning about uninitialized `pair' variable.

Release 2.6.7

- [FEATURE] Implement the QL extension (offered by default).
- [BUGFIX] Abort when encountering unexpected HTTP/3 frames.
- [BUGFIX] Acknowledge (QPACK) HTTP/3 trailers correctly.
- [DEBUG] Turn on debug message for next advisory tick.

Release 2.6.4

- [BUGFIX] High priority buffered packet queue length.
- [BUGFIX] Rain time calculation: max_ack_delay is in milliseconds.

Release 2.6.2

- [BUGFIX] SCID!=ODCID rule applies to Retry packets, not regular
packets.
- [BUGFIX] Zero-RTT: BoringSSL no longer flips read/write secrets.
- [BUGFIX] Truncate ACK frame rather instead of aborting IETF
connection.
- [BUGFIX] Client: don't send duplicate reset tokens.
- [BUGFIX] Remove invalid assertion in H3 framing code.
- Silence a warning in send ctl by restructuring switch() statement.

Release 2.6.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 24 support

Release 2.5.2

- [BUGFIX] argument order to gQUIC client constructor. Regression
introduced in 2.5.0.
- [BUGFIX] split buffered packet error recovery: destroy the correct
packet.

Release 2.5.0

- [API] lsquic_engine_connect() can now be passed QUIC version to use.
- [OPTIMIZATION] Queue opportunistic ACKs if there is data to be sent.
- [BUGFIX] Don't evict streams from priority iterator if there is
only one queue.
- [OPTIMIZATION, BUGFIX] Several other optimizations and bug fixes.
- Use ls-qpack v0.10.7.

Release 2.4.9

- [BUGFIX] IETF QUIC server: fix uninitialized variable use.
- [BUGFIX] make sure TLSv1.3 is not disabled in SSL object.
- [BUGFIX] Use issuer name and serial number to cache certs (SKID
values are not unique).
- [BUGFIX] Always set the idle alarm in IETF connection so that it
can time out.

Release 2.4.7

- Add echo client and server to the distibution.
- Add MD5 client and server to the distibution.
- Fix http_client: check command-line arguments better, prevent crash.
- Fix IETF conn: can_write_ack() should only care about APP PNS.
- Client: delay stream creation until handshake succeds.
- Reset HTTP stream whose write end is closed prematurely.
- Fix tickable(): mirror behavior of tick() wrt buffered packets.
- Log reason why engine is tickable.

Release 2.4.4

- [API] Add lsquic_alpn2ver() to aid parsing Alt-Svc header.
- [BUGFIX] NULL dereference when H3 frame header would be split.
- [BUGFIX] Do not close fixed-size H3 frame prematurely.
- [BUGFIX] Allow PING frames in IETF mini conn.
- [BUGFIX] Mini conns: don't send any packets after receiving
CONNECTION_CLOSE.
- [BUGFIX] Client migration: reserve slot for DCID from transport params.
- [BUGFIX] Allow max_early_data_size=0 -- early_data might not be there.
- [BUGFIX] Use an invalid stream number to reset BPT cache (zero is now a
valid stream number).
- [SPEC] Use FINAL_SIZE_ERROR when FIN mismatch is detected.
- [OPTIMIZATION] Closed connection only gets one chance to send packets.
- [OPTIMIZATION] Flush headers stream before packetizing stream data.
- [OPTIMIZATION] process QPACK encoder STREAM frames immediately.
- Update ls-qpack to v0.10.1.

Release 2.4.0

[FEATURE] QUIC and HTTP/3 Internet Draft 23 support

Release 2.3.0

- [FEATURE] BBR congestion control is on by default
- [BUGFIX] BBR app-limited logic
- [BUGFIX] Fix uninitialized warnings in IETF
- [BUGFIX] Update ls-qpack to v0.9.14
- [CLEANUP] Code cleanup

Release 2.2.0: server included, ID-22 supported (#76)

Release 1.21.0

[FEATURE] Add qlog log module.

Release 1.19.0

- [FEATURE, API Change] 0-RTT support. Add function to export 0-RTT
information; it can be supplied to a subsequent connect() call.
- [FEATURE] Add -0 flag to http_client to exercise 0-RTT support.
- [BUGFIX] Resuscitate the Windows build.
- [BUGFIX] Send HTTP settings (max header list size) if necessary.
- [BUGFIX] Buffered packets can contain ACK frames.
- [BUGFIX] Make packet writeable once all STREAM frames are elided.
- [BUGFIX] Fix potential null dereference when realloc fails.
- cmake: simplify build configuration.

Release 1.18.0

- [API Change] Can specify clock granularity in engine settings.
- [BUGFIX] Pacer uses fixed clock granularity. Since the change on
2018-04-09, it is not necessary to try to approximate the next tick
time in the pacer: it can use fix clock granularity specified by
the user.
- [BUGFIX] Do not tick constantly before handshake is done.
- [BUGFIX] Do not exit tick prematurely: reuse packet with ACK. Even
if we cannot allocate *more* packets, we could still be able to write
to one already allocated.
- [BUGFIX] Do not schedule pacer if there are no lost packets.

Release 1.17.14

- [FEATURE] http_client can now collect stats: time to connect, TTFB,
time to download, requests per seconds, and bandwidth. See -t flag.

- [BUGFIX] http_client: -B, -K, and -r can be used at the same time.

- [BUGFIX] http_client: do not display cert chain before each request.
Now this is only done once per connection, if the handshake is
successful and -a option is given.

- [BUGFIX] Do not wait to dispatch on_close() after reading. If a
stream is scheduled to be closed after on_read() callback returns,
close it immediately instead of waiting until the end of the tick.
If client creates new request from on_close() event, they will be
processed in the same tick instead of waiting for the next one.

- [BUGFIX] HEADERS stream is critical: always treat it with highest
priority.

Release 1.17.11

Fix strict aliasing warning in when compiling with optimizations

Release 1.17.9

[BUGFIX] Engine: reduce minumum batch size from 256 to 4

Release 1.17.8

[BUGFIX] Fix compilation on FreeBSD and 32-bit Linux

Release 1.17.6

- Add failsafe: resume sending packets after some time

The change puts a 1-second limit on the amount of time the engine
will not send packets after some packets are delayed. This makes
the library robust in case the user does not unblock the engine
explicitly using lsquic_engine_send_unsent_packets() call.

- [BUGFIX] Handle corner cases in send controller when packets are
a) delayed or b) dropped during repackaging.

- [BUGFIX] Memory leak: destroy buffered packets during controller
cleanup.

Release 1.17.3

[BUGFIX] Do not send STOP_WAITING frames when using Q044

Release 1.17.0

- [API Change] Packet out Memory Interface (PMI) update:
- Split PMI pool return into pmi_release and pmi_return
- PMI callbacks take peer_ctx and is_ipv6 arguments
- [BUGFIX] Fix use-after-free when certificate is updated
- Silence gcc warning in optimized mode by performing useless
initialization
- cmake: use the standard variable CMAKE_BUILD_TYPE instead of
DEVEL_MODE

Release 1.14.0

- [API Change] Disable packet sending if full batch cannot be sent
If lsquic_packets_out_f() cannot send the whole batch, disable
packet sending until lsquic_engine_send_unsent_packets() is called.
- [BUGFIX] Handle case when STREAM frame does not fit.
- [BUGFIX] Always allow incoming STREAM frames to overlap. Peers
may send overlapping STREAM frames even if using versions older
than Q043.
- Custom header set fixes:
- set "FIN reached" flag when custom header with FIN flag is
claimed;
- do not return custom header set for a reset stream.

1.13.0: [FEATURE, API Change] HTTP header bypass

Add ability to create custom header set objects via callbacks.
This avoids reading and re-parsing headers from the stream.

See test/http_client.c for example implementation. (Use -B flag
to turn it on).

1.12.4: Fix memory leaks and gcc compilation warnings

1.12.0: [FEATURE, API Change] Certificate verification

1.11.0: [FEATURE] Add support for Q044

[BUGFIX] allow multiple parallel connections by default

Use the original method of tracking connections by CIDs by default.
If zero-sized CID support is turned on, connections are tracked by
the address. A new connection is not created if another connection
is using the same network address.

[FEATURE, API CHANGE] Support zero-sized CIDs in received packets

Close connection properly when packet encryption fails

Latest changes

- [API Change] Add optional callback to call when handshake is done
- [API Change, BUGFIX] After send failure, wait until transport available

Latest changes

- [BUGFIX] Frame insertion mis-ID as overlap instead of dup
- http_client: fix priority range generated by -E flag

Fix indentation: this is a better way to address new gcc warnings

Fix bug in lsquic_engine_connect() exposed by recent changes.

Latest changes

- [BUGFIX] Add connection to Tickable Queue on stream write
- cmake: use MSVC variable instead of trying to detect
- engine: improve connection incref/decref logging
- stream: don't ignore errors that may occur on triggered flush
- connection: remove obsolete method
- engine: indicate connection as tickable if previous call went
over threshold

[API Change, OPTIMIZATION] Only process conns that need to be processed

The API is simplified: do not expose the user code to several
queues. A "connection queue" is now an internal concept.
The user processes connections using the single function
lsquic_engine_process_conns(). When this function is called,
only those connections are processed that need to be processed.
A connection needs to be processed when:

1. New incoming packets have been fed to the connection.
2. User wants to read from a stream that is readable.
3. User wants to write to a stream that is writeable.
4. There are buffered packets that can be sent out. (This
means that the user wrote to a stream outside of the
lsquic library callback.)
5. A control frame (such as BLOCKED) needs to be sent out.
6. A stream needs to be serviced or delayed stream needs to
be created.
7. An alarm rings.
8. Pacer timer expires.

To achieve this, the library places the connections into two
priority queues (min heaps):

1. Tickable Queue; and
2. Advisory Tick Time queue (ATTQ).

Each time lsquic_engine_process_conns() is called, the Tickable
Queue is emptied. After the connections have been ticked, they are
queried again: if a connection is not being closed, it is placed
either in the Tickable Queue if it is ready to be ticked again or
it is placed in the Advisory Tick Time Queue. It is assumed that
a connection always has at least one timer set (the idle alarm).

The connections in the Tickable Queue are arranged in the least
recently ticked order. This lets connections that have been quiet
longer to get their packets scheduled first.

This change means that the library no longer needs to be ticked
periodically. The user code can query the library when is the
next tick event and schedule it exactly. When connections are
processed, only the tickable connections are processed, not *all*
the connections. When there are no tick events, it means that no
timer event is necessary -- only the file descriptor READ event
is active.

The following are improvements and simplifications that have
been triggered:

- Queue of connections with incoming packets is gone.
- "Pending Read/Write Events" Queue is gone (along with its
history and progress checks). This queue has become the
Tickable Queue.
- The connection hash no longer needs to track the connection
insertion order.

Update copyright year; add CONTRIBUTORS.txt

Update CHANGELOG, a few changes

updated to upstream ran all tests again.

compiles in debug/release. tests pass (in debug config at least)

Latest changes

- [OPTIMIZATION] Merge series of ACKs if possible

Parsed single-range ACK frames (that is the majority of frames) are
saved in the connection and their processing is deferred until the
connection is ticked. If several ACKs come in a series between
adjacent ticks, we check whether the latest ACK is a strict superset
of the saved ACK. If it is, the older ACK is not processed.

If ACK frames can be merged, they are merged and only one of them is
either processed or saved.

- [OPTIMIZATION] Speed up ACK verification by simplifying send history.

Never generate a gap in the sent packet number sequence. This reduces
the send history to a single number instead of potentially a series of
packet ranges and thereby speeds up ACK verification.

By default, detecting a gap in the send history is not fatal: only a
single warning is generated per connection. The connection can continue
to operate even if the ACK verification code is not able to detect some
inconsistencies.

- [OPTIMIZATION] Rearrange the lsquic_send_ctl struct

The first part of struct lsquic_send_ctl now consists of members that
are used in lsquic_send_ctl_got_ack() (in the absense of packet loss,
which is the normal case). To speed up reads and writes, we no longer
try to save space by using 8- and 16-bit integers. Use regular integer
width for everything.

- [OPTIMIZATION] Cache size of sent packet.

- [OPTIMIZATION] Keep track of the largest ACKed in packet_out

Instead of parsing our own ACK frames when packet has been acked,
use the value saved in the packet_out structure when the ACK frame
was generated.

- [OPTIMIZATION] Take RTT sampling conditional out of ACK loop

- [OPTIMIZATION] ACK processing: only call clock_gettime() if needed

- [OPTIMIZATION] Several code-level optimizations to ACK processing.

- Fix: http_client: fix -I flag; switch assert() to abort()

Latest changes

- Fix unit test regression: enable them correctly in cmake.
- Simplify connection has interface

Latest changes

- [API Change] lsquic_engine_connect() returns pointer to the connection
object.
- [API Change] Add lsquic_conn_get_engine() to get engine object from
connection object.
- [API Change] Add lsquic_conn_status() to query connection status.
- [API Change] Add add lsquic_conn_set_ctx().
- [API Change] Add new timestamp format, e.g. 2017-03-21 13:43:46.671345
- [OPTIMIZATION] Process handshake STREAM frames as soon as packet
arrives.
- [OPTIMIZATION] Do not compile expensive send controller sanity check
by default.
- [OPTIMIZATION] Add fast path to gquic_be_gen_reg_pkt_header.
- [OPTIMIZATION] Only make squeeze function call if necessary.
- [OPTIMIZATION] Speed up Q039 ACK frame parsing.
- [OPTIMIZATION] Fit most used elements of packet_out into first 64 bytes.
- [OPTIMIZATION] Keep track of scheduled bytes instead of calculating.
- [OPTIMIZATION] Prefetch next unacked packet when processing ACK.
- [OPTIMIZATION] Leverage fact that ACK ranges and unacked list are.
ordered.
- [OPTIMIZATION] Reduce function pointer use for STREAM frame generation
- Fix: reset incoming streams that arrive after we send GOAWAY.
- Fix: delay client on_new_conn() call until connection is fully set up.
- Fixes to buffered packets logic: splitting, STREAM frame elision.
- Fix: do not dispatch on_write callback if no packets are available.
- Fix WINDOW_UPDATE send and resend logic.
- Fix STREAM frame extension code.
- Fix: Drop unflushed data when stream is reset.
- Switch to tracking CWND using bytes rather than packets.
- Fix TCP friendly adjustment in cubic.
- Fix: do not generate invalid STOP_WAITING frames during high packet
loss.
- Pacer fixes.

Latest changes

- [API Change] Sendfile-like functionality is gone. The stream no
longer opens files and deals with file descriptors. (Among other
things, this makes the code more portable.) Three writing functions
are provided:

lsquic_stream_write
lsquic_stream_writev
lsquic_stream_writef (NEW)

lsquic_stream_writef() is given an abstract reader that has function
pointers for size() and read() functions which the user can implement.
This is the most flexible way. lsquic_stream_write() and
lsquic_stream_writev() are now both implemented as wrappers around
lsquic_stream_writef().

- [OPTIMIZATION] When writing to stream, be it within or without the
on_write() callback, place data directly into packet buffer,
bypassing auxiliary data structures. This reduces amount of memory
required, for the amount of data that can be written is limited
by the congestion window.

To support writes outside the on_write() callback, we keep N
outgoing packet buffers per connection which can be written to
by any stream. One half of these are reserved for the highest
priority stream(s), the other half for all other streams. This way,
low-priority streams cannot write instead of high-priority streams
and, on the other hand, low-priority streams get a chance to send
their packets out.

The algorithm is as follows:

- When user writes to stream outside of the callback:
- If this is the highest priority stream, place it onto the
reserved N/2 queue or fail.
(The actual size of this queue is dynamic -- MAX(N/2, CWND) --
rather than N/2, allowing high-priority streams to write as
much as can be sent.)
- If the stream is not the highest priority, try to place the
data onto the reserved N/2 queue or fail.
- When tick occurs *and* more packets can be scheduled:
- Transfer packets from the high N/2 queue to the scheduled
queue.
- If more scheduling is allowed:
- Call on_write callbacks for highest-priority streams,
placing resulting packets directly onto the scheduled queue.
- If more scheduling is allowed:
- Transfer packets from the low N/2 queue to the scheduled
queue.
- If more scheduling is allowed:
- Call on_write callbacks for non-highest-priority streams,
placing resulting packets directly onto the scheduled queue

The number N is currently 20, but it could be varied based on
resource usage.

- If stream is created due to incoming headers, make headers readable
from on_new.

- Outgoing packets are no longer marked non-writeable to prevent placing
more than one STREAM frame from the same stream into a single packet.
This property is maintained via code flow and an explicit check.
Packets for stream data are allocated using a special function.

- STREAM frame elision is cheaper, as we only perform it if a reset
stream has outgoing packets referencing it.

- lsquic_packet_out_t is smaller, as stream_rec elements are now
inside a union.

Latest changes

- Hide handshake implementation behind a set of function pointers
- Use monotonically increasing clock
- Make sure that retx delay is not larger than the max of 60 seconds

Latest changes

- Add support for Q041; drop support for Q040

LSQUIC Client: Initial release