Release 3.1.0

Release 2.30.0

- [FEATURE] Added support for sending/receiving multiple headers to address the
case related to "100 continue" header handling.
- [BUGFIX] Addressed high CPU usage for a GOAWAY connection before sending
CONNECTION_CLOSE.
- [BUGFIX] Addressed SIGFPE due to zero pacing rate. (ISSUE #254).
- [BUGFIX] Fixed a minor issue related to multi-paths.

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 2.27.1

- [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 2.26.2

- [BUGFIX] Do not drop incoming data when STOP_SENDING is received.
- [BUGFIX] Receipt of STOP_SENDING should not cause read-reset.
- [BUGFIX] Allow stream writes after receiving RESET.
- [BUGFIX] Typo in stream: ANDing enum with wrong flag.
- [BUGFIX] Reset elision: do not use zero as special stream ID value,
for zero is a valid stream ID in IETF QUIC.
- [API] Add optional on_conncloseframe_received() callback.
- Use zero error code in RESET stream sent in response to STOP_SENDING.

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 2.23.0

- [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.

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 2.18.0

- [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 2.17.0

- [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 2.16.1

- [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.

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.

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.

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 2.8.7

- [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 2.8.4

- [HTTP3] Verify number of bytes in incoming DATA frames against
content-length.
- [HTTP3] Stop issuing streams credits if peer stops opening QPACK
decoder window. This addresses a potential attack whereby client
can cause the server to keep allocating memory. See Security
Considerations in the QPACK draft.
- [BUGFIX] Mini conn: don't shorten max packet size for Q050 and later.
- [BUGFIX] Init IETF connection flow controller using correct setting.
- Code cleanup and minor fixes.

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 2.6.7

- [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 2.5.0

- [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 2.4.5

- [OPTIMIZATION]: flush encoder stream only when necessary.
- [BUGFIX] Use ls-qpack v0.10.2 for new API -- and for a bug fix.
- [BUGFIX] Typo in IETF conn SETTINGS writer.
- Use latest BoringSSL.

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 2.4.0

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

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

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

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.

Latest changes:

- [API] Expose useful lsquic_ver2str[] in lsquic.h
- [BUGFIX] Do not produce packet sequence gaps due to STREAM frame elision

Latest changes

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

[FEATURE] Add support for Q042

[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

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

- Do not send RST_STREAM when stream is closed for reading
- Raise maximum header size from 4K to 64K
- Check header name and value lengths against maximum imposed by HPACK
- Fix NULL dereference in stream flow controller

LSQUIC Client: Initial release