Define a new function h3_is_frame_valid(). It returns if a frame is
valid or not depending on the stream which received it.
For the moment, it is used in h3_decode_qcs() which only deals with
bidirectional streams. Soon, uni streams will use the same function,
rendering the frame type check useful.
Define a new function h3_init_uni_stream(). This can be used to read the
stream type of an unidirectional stream. There is no functional change
with previous code.
This patch will be useful to unify reception for uni streams with
bidirectional ones.
Define a new enum h3s_t. This is used to differentiate between the
different stream types used in a HTTP/3 connection, including the QPACK
encoder/decoder streams.
For the moment, only bidirectional streams is positioned. This patch
will be useful to unify reception of uni streams with bidirectional
ones.
Replace h3_uqs type by qcs in stream callbacks. This change is done in
the context of unification between bidi and uni-streams. h3_uqs type
will be unneeded when this is achieved.
Remove the unneeded skip over unidirectional streams in qc_send(). This
unify sending for both uni and bidi streams.
In fact, the only local unidirectional streams in use for the moment is
the H3 Control stream responsible of SETTINGS emission. The frame was
already properly generated in qcs.tx.buf, but not send due to stream
skip in qc_send(). Now, there is no need to ignore uni streams so remove
this condition.
This fixes the emission of H3 settings which is now properly emitted.
Uni and bidi streams use the same set of funtcions for sending. One of
the most notable gain is that flow-control is now enforced for uni
streams.
The whole frame payload must have been received to demux a H3 frames,
except for H3 DATA which can be fragmented into multiple HTX blocks.
If the frame is bigger than the buffer and is not a DATA frame, a
connection error is reported with error H3_EXCESSIVE_LOAD.
This should be completed in the future with the H3 settings to limit the
size of uncompressed header section.
This code is more generic : it can handle every H3 frames. This is done
in order to be able to use h3_decode_qcs() to demux both uni and bidir
streams.
The only change is that the H3_CF_SETTINGS_SENT flag if-condition is
replaced by a BUG_ON statement. This may help to catch multiple calls on
h3_control_send() instead of silently ignore them.
h3_parse_settings_frm() read one byte after the frame payload. Fix the
parsing code. In most cases, this has no impact as we are inside an
allocated buffer but it could cause a segfault depending on the buffer
alignment.
struct h3 represents the whole HTTP/3 connection. A new type h3s was
recently introduced to represent a single HTTP/3 stream. To facilitate
the analogy with other haproxy code, most notable in MUX, rename h3 type
to h3c.
h3_b_dup() is used to obtains a ncbuf representation into a struct
buffer. ncbuf can thus be marked as a const parameter. This will allows
function which already manipulates a const ncbuf to use it.
Send MAX_STREAM_DATA frames when at least half of the allocated
flow-control has been demuxed, frame and cleared. This is necessary to
support QUIC STREAM with received data greater than a buffer.
Transcoders must use the new function qcc_consume_qcs() to empty the QCS
buffer. This will allow to monitor current flow-control level and
generate a MAX_STREAM_DATA frame if required. This frame will be emitted
via qc_io_cb().
Flag QCS if HTX buffer is full on demux. This will block all future
operations on QCS demux and should limit unnecessary decode_qcs() calls.
The flag is cleared on rcv_buf operation called by conn-stream.
Previously, H3 demuxer refused to proceed the payload if the frame was
not entirely received and the QCS buffer is not full. This code was
duplicated from the H2 demuxer.
In H2, this is a justified optimization as only one frame at a time can
be demuxed. However, this is not the case in H3 with interleaved frames
in the lower layer QUIC STREAM frames.
This condition is now removed. H3 demuxer will proceed payload as soon
as possible. An exception is kept for HEADERS frame as the code is not
able to deal with partial HEADERS.
With this change, H3 demuxer should consume less memory. To ensure that
we never received a HEADER bigger than the RX buffer, we should use the
H3 SETTINGS_MAX_FIELD_SECTION_SIZE.
This commit is the equivalent for uni-streams of previous commit
MEDIUM: mux-quic/h3/hq-interop: use ncbuf for bidir streams
All unidirectional streams data is now handle in MUX Rx ncbuf. The
obsolete buffer is not unused and will be cleared in the following
patches.
Add a ncbuf for data reception on qcs. Thanks to this, the MUX is able
to buffered all received frame directly into the buffer. Flow control
parameters will be used to ensure there is never an overflow.
This change will simplify Rx path with the future deletion of acked
frames tree previously used for frames out of order.
HTTP/3 implementation must ignore unknown frame type to support protocol
evolution. Clients can deliberately use unknown type to test that the
server is conformant : this principle is called greasing.
Quiche client uses greasing on H3 frame type with a zero length frame.
This reveals a bug in H3 parsing code which causes the transfer to be
interrupted. Fix this by removing the break statement on ret variable.
Now the parsing loop is only interrupted if input buffer is empty or the
demux is blocked.
This should fix http/3 freeze transfers with the quiche client. Thanks
to Lucas Pardue from Cloudflare for his report on the bug. Frédéric
Lecaille quickly found the source of the problem which helps me to write
this patch.
If the request channel buffer is full, H3 demuxing must be interrupted
on the stream until some read is performed. This condition is reported
if the HTX stream buffer qcs.rx.app_buf is full.
In this case, qcs instance is marked with a new flag QC_SF_DEM_FULL.
This flag cause the H3 demuxing to be interrupted. It is cleared when
the HTX buffer is read by the conn-stream layer through rcv_buf
operation.
When the flag is cleared, the MUX tasklet is woken up. However, as MUX
iocb does not treat Rx for the moment, this is useless. It must be fix
to prevent possible freeze on POST transfers.
In practice, for the moment the HTX buffer is never full as the current
Rx code is limited by the quic-conn receive buffer size and the
incomplete flow-control implementation. So for now this patch is not
testable under the current conditions.
Add a loop in the bidi STREAM function. This will call repeatdly
qcc_decode_qcs() and dequeue buffered frames.
This is useful when reception of more data is interrupted because the
MUX buffer was full. qcc_decode_qcs() has probably free some space so it
is useful to immediatly retry reception of buffered frames of the qcs
tree.
This may fix occurences of stalled Rx transfers with large payload.
Note however that there is still room for improvment. The conn-stream
layer is not able at this moment to retrigger demuxing. This is because
the mux io-handler does not treat Rx : this may continue to cause
stalled tranfers.
Previously, h3 layer was not able to demux a DATA frame if not fully
received in the Rx buffer. This causes evident limitation and prevents
to be able to demux a frame bigger than the buffer.
Improve h3_data_to_htx() to support partial frame demuxing. The demux
state is preserved in the h3s new fields : this is useful to keep the
current type and length of the demuxed frame.
Define a new structure h3s used to provide context for a H3 stream. This
structure is allocated and stored in the qcs thanks to previous commit
which provides app-layer context storage.
For now, h3s is empty. It will soon be completed to be able to support
stateful demux : this is required to be able to demux an incomplete
frame if the rx buffer is full.
Edit the functions used for HEADERS and DATA parsing. They now return
the number of bytes handled.
This change will help to demux H3 frames bigger than the buffer.
Handle wrapping buffer in h3_data_to_htx(). If data is wrapping, first
copy the contiguous data, then copy the data in front of the buffer.
Note that h3_headers_to_htx() is not able to handle wrapping data. For
the moment, a BUG_ON was added as a reminder. This cas never happened,
most probably because HEADERS is the first frame of the stream.
Always set HTX flag HTX_SL_F_XFER_LEN for http/3. This is correct
becuase the size of H3 requests is always known thanks to the protocol
framing.
This may fix occurences of incomplete POST requests when the client side
of the connection has been closed before.
The conn-stream endpoint is now shared between the conn-stream and the
applet or the multiplexer. If the mux or the applet is created first, it is
responsible to also create the endpoint and share it with the conn-stream.
If the conn-stream is created first, it is the opposite.
When the endpoint is only owned by an applet or a mux, it is called an
orphan endpoint (there is no conn-stream). When it is only owned by a
conn-stream, it is called a detached endpoint (there is no mux/applet).
The last entity that owns an endpoint is responsible to release it. When a
mux or an applet is detached from a conn-stream, the conn-stream
relinquishes the endpoint to recreate a new one. This way, the endpoint
state is never lost for the mux or the applet.
Some CS flags, only related to the endpoint, are moved into the endpoint
struct. More will probably moved later. Those ones are not critical. So it
is pretty safe to move them now and this will ease next changes.
Group the endpoint target of a conn-stream, its context and the associated
flags in a dedicated structure in the conn-stream. It is not inlined in the
conn-stream structure. There is a dedicated pool.
For now, there is no complexity. It is just an indirection to get the
endpoint or its context. But the purpose of this structure is to be able to
share a refcounted context between the mux and the conn-stream. This way, it
will be possible to preserve it when the mux is detached from the
conn-stream.
This change is only significant for the multiplexer part. For the applets,
the context and the endpoint are the same. Thus, there is no much change. For
the multiplexer part, the connection was used to set the conn-stream
endpoint and the mux's stream was the context. But it is a bit strange
because once a mux is installed, it takes over the connection. In a
wonderful world, the connection should be totally hidden behind the mux. The
stream-interface and, in a lesser extent, the stream, still access the
connection because that was inherited from the pre-multiplexer era.
Now, the conn-stream endpoint is the mux's stream (an opaque entity for the
conn-stream) and the connection is the context. Dedicated functions have
been added to attached an applet or a mux to a conn-stream.
qcs by_id field has been replaced by a new field named "id". Adjust the
h3_debug_printf traces. This is the case since the introduction of the
qc_stream_desc type.
Add a new app layer operation is_active. This can be used by the MUX to
check if the connection can be considered as active or not. This is used
inside qcc_is_dead as a first check.
For example on HTTP/3, if there is at least one bidir client stream
opened the connection is active. This explicitly ignore the uni streams
used for control and qpack as they can never be closed during the
connection lifetime.
This one has been detected by valgrind:
==2179331== Conditional jump or move depends on uninitialised value(s)
==2179331== at 0x1B6EDE: qcs_notify_recv (mux_quic.c:201)
==2179331== by 0x1A17C5: qc_handle_uni_strm_frm (xprt_quic.c:2254)
==2179331== by 0x1A1982: qc_handle_strm_frm (xprt_quic.c:2286)
==2179331== by 0x1A2CDB: qc_parse_pkt_frms (xprt_quic.c:2550)
==2179331== by 0x1A6068: qc_treat_rx_pkts (xprt_quic.c:3463)
==2179331== by 0x1A6C3D: quic_conn_app_io_cb (xprt_quic.c:3589)
==2179331== by 0x3AA566: run_tasks_from_lists (task.c:580)
==2179331== by 0x3AB197: process_runnable_tasks (task.c:883)
==2179331== by 0x357E56: run_poll_loop (haproxy.c:2750)
==2179331== by 0x358366: run_thread_poll_loop (haproxy.c:2921)
==2179331== by 0x3598D2: main (haproxy.c:3538)
==2179331==
Implement the release app-ops ops for H3 layer. This is used to clean up
uni-directional streams and the h3 context.
This prevents a memory leak on H3 resources for each connection.
Regroup some cleaning operations inside a new function qcs_free. This
can be used for all streams, both through qcs_destroy and with
uni-directional streams.
H3_DEBUG definition is removed from h3.c similarly to the commit
d96361b2703a6364c1116af76016f09807b4c65b
CLEANUP: qpack: suppress by default stdout traces
Also, a plain fprintf in h3_snd_buf has been replaced to be conditional
to the H3_DEBUG definition.
These changes reduces the default output on stdout with QUIC traffic.
Thanks to all previous changes, it is now possible to move the
stream-interface into the conn-stream. To do so, some SI functions are
removed and their conn-stream counterparts are added. In addition, the
conn-stream is now responsible to create and release the
stream-interface. While the stream-interfaces were inlined in the stream
structure, there is now a pointer in the conn-stream. stream-interfaces are
now dynamically allocated. Thus a dedicated pool is added. It is a temporary
change because, at the end, the stream-interface structure will most
probably disappear.
Some variables were only checked via BUG_ON macro. If compiling without
DEBUG_STRICT, this instruction is a noop. Fix this by using an explicit
condition + ABORT_NOW.
This should fix the github issue #1549.
Inspect return code of HEADERS/DATA parsing functions and use a BUG_ON
to signal an error. The stream should be closed to handle the error
in a more clean fashion.
Add a new function h3_data_to_htx. This function is used to parse a H3
DATA frame and copy it in the mux stream HTX buffer. This is required to
support HTTP POST data.
Note that partial transfers if the HTX buffer is fulled is not properly
handle. This causes large DATA transfer to fail at the moment.
Move the HEADERS parsing code outside of generic h3_decode_qcs to a new
dedicated function h3_headers_to_htx. The benefit will be visible when
other H3 frames parsing will be implemented such as DATA.
