Release 3.1.0

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 2.23.2

- 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 2.23.1

- [BUGFIX] Regression introduced in 2.22.0: use correct number of
PNSs for IETF mini conn during promotion.

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)

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.

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 2.19.0

- [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 2.15.0

- [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 2.14.7

- [BUGFIX] ALPN-to-version mapping: do not skip h3-Q050.
- [BUGFIX] Frame reader: skip headers if target stream is closed.

Release 2.14.3

- [BUGFIX] gQUIC: pass correct stream to hsi_create_header_set() callback.
- [BUGFIX] Use ls-hpack 2.1.1
- Improve stream code readability.
- Use ls-qpack 2.0.5

Release 2.14.0

- [API] Use lsxpack_header structure to send HTTP headers.
- [OPTIMIZATION] nocopy's readable_bytes() function.
- http_server: fix typo in error message
- Use ls-hpack 2.1.0.
- Use ls-qpack 2.0.0.

Code cleanup. Improve comments in lsquic.h

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 2.7.0

- [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 2.4.7

- 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 2.4.2

- [BUGFIX] H3 framing: fix zero-byte write when space is available
- [BUGFIX] Don't send STREAM frame when incoming unidirectgional stream
is closed
- [BUGFIX] Cancel all pending writes by stream reset by a GOAWAY
- [BUGFIX] Fix use-after-free in IETF full conn
- [OPTIMIZATION] Wait for session tickets for two seconds and then drop
SSL object and crypto streams.

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 1.19.0

- [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 1.17.15

- [BUGFIX] http_client: make sure only one read per on_read() callback
is performed in the header conversion bypass (-B) mode.
- http_client: with -E, assign random priority when stream is created.
- [OPTIMIZATION] On immediate write, place an ACK frame into the first
buffered packet if an ACK is queued. This reduces the number of
standalone ACK packets.
- [OPTIMIZATION] Allow placing more than one STREAM frame from the same
stream into an outgoing packet. This change minimizes the number of
buffered packets required to store several small HTTP messages by
virtue of allowing more than one STREAM frame from HEADERS stream in
the same packet.
- [OPTIMIZATION] Flush headers when writing to buffered packets. This
causes the headers to be written to the same buffered packet queue,
thereby improving packet utilization, especially for small HTTP
messages.

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

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

Close connection properly when packet encryption fails

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

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

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

- 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

LSQUIC Client: Initial release