Modify qc_send_app_pkt() to distinguish the case where it sends new data
against the case where it sends old data during probing retransmissions.
We add <old_data> boolean parameter to this function to do so. The mux
never directly send old data when probing retransmissions are needed by
the connection.
We want to track the frames which have been duplicated during retransmissions so
that to avoid uselessly retransmitting frames which would already have been
acknowledged. ->origin new member is there to store the frame from which a copy
was done, ->reflist is a list to store the frames which are copies.
Also ensure all the frames are zeroed and that their ->reflist list member is
initialized.
Add QUIC_FL_TX_FRAME_ACKED flag definition to mark a TX frame as acknowledged.
Define 2 new callback for qcc_app_ops : attach and detach. They are
called when a qcs instance is respectively allocated and freed. If
implemented, they can allocate a custom context stored in the new
abstract field ctx of qcs.
For now, h3 and hq-interop does not use these new callbacks. They will
be soon implemented by the h3 layer to allocate a context used for
stateful demuxing.
This change is required to support the demuxing of H3 frames bigger than
a buffer.
Improve the reception for STREAM frames. In qcc_recv(), if the frame is
bigger than the remaining space in rx buffer, do not reject it wholly.
Instead, copy as much data as possible. The rest of the data is
buffered.
This is necessary to handle H3 frames bigger than a buffer. The H3 code
does not demux until the frame is complete or the buffer is full.
Without this, the transfer on payload larger than the Rx buffer can
rapidly freeze.
Add new qcs fields to count the sum of bytes received for each stream.
This is necessary to enforce flow-control for reception on the peer.
For the moment, the implementation is partial. No MAX_STREAM_DATA or
FLOW_CONTROL_ERROR are emitted. BUG_ON statements are here as a
remainder.
This means that for the moment we do not support POST payloads greater
that the initial max-stream-data announced (256k currently).
At least, we now ensure that we never buffer a frame which overflows the
flow-control limit : this ensures that the memory consumption per stream
should stay under control.
qcs and its field are not properly freed if the conn-stream allocation
fail in qcs_new(). Fix this by having a proper deinit code with a
dedicated label.
Comments were not properly edited since the splitting of functions for
stream emission. Also "payload" argument has been renamed to "in" as it
better reflects the function purpose.
Remove CS_EP_EOS set erroneously on qc_rcv_buf().
This fixes POST with abortonclose. Previously, request was preemptively
aborted by haproxy due to the incorrect EOS flag.
For the moment, EOS flag is not set anymore. It should be set to warn
about a premature close from the client.
Since previous patch
MINOR: mux-quic: split xfer and STREAM frames build
there is no way to report an error in qcs_xfer_data().
This should fix github issue #1669.
Do not initialize mux task timeout if timeout client is set to 0 in the
configuration. Check for the task before queuing it in qc_io_cb() or
qc_detach().
This fix a crash when timeout client is 0 or undefined.
Unsubscribe from lower layer on qc_release. This ensures that the lower
layer won't wake up a null tasklet after the MUX has been released and
may prevent a crash.
Complete qc_send function. After having processed each qcs emission, it
will now retry send on qcs where transfer can continue. This is useful
when qc_stream_desc buffer is full and there is still data present in
qcs buf.
To implement this, each eligible qcs is inserted in a new list
<qcc.send_retry_list>. This is done on send notification from the
transport layer through qcc_streams_sent_done(). Retry emission until
send_retry_list is empty or the transport layer cannot proceed more
data.
Several send operations are now called on two different places. Thus a
new _qc_send_qcs() function is defined to factorize the code.
This change should maximize the throughput during QUIC transfers.
MUX streams can now allocate multiple buffers for sending. quic-conn is
responsible to limit the total count of allowed allocated buffers. A
counter is stored in the new field <stream_buf_count>.
For the moment, the value is hardcoded to 30.
On stream buffer allocation failure, the qcc MUX is flagged with
QC_CF_CONN_FULL. The MUX is then woken up as soon as a buffer is freed,
most notably on ACK reception.
Complete the qc_stream_desc type to support multiple buffers on
emission. The main objective is to increase the transfer throughput.
The MUX is now able to transfer more data without having to wait ACKs.
To implement this feature, a new type qc_stream_buf is declared. it
encapsulates a buffer with a list element. New functions are defined to
retrieve the current buffer, release it or allocate a new one. Each
buffer is kept in the qc_stream_desc list until all of its data is
acknowledged.
On the MUX side, a qcs uses the current stream buffer to transfer data.
Once the buffer is full, it is released and a new one will be allocated
on a future qc_send() invocation.
Simplify the model qcs/qc_stream_desc. Each types has now its own tree
node, stored respectively in qcc and quic-conn trees. It is still
necessary to mark the stream as detached by the MUX once all data is
transfered to the lower layer.
This might improve slightly the performance on ACK management as now
only the lookup in quic-conn is necessary. On the other hand, memory
size of qcs structure is increased.
Regroup all type definitions and functions related to qc_stream_desc in
the source file src/quic_stream.c.
qc_stream_desc complexity will be increased with the development of Tx
multi-buffers. Having a dedicated module is useful to mix it with
pure transport/quic-conn code.
Split qcs_push_frame() in two functions.
The first one is qcs_xfer_data(). Its purpose is to transfer data from
qcs.tx.buf to qc_stream_desc buffer. The second function is named
qcs_build_stream_frm(). It generates a STREAM frame using qc_stream_desc
buffer as payload.
The trace events previously associated with qcs_push_frame() has also
been split in two to reflect the new code structure.
The purpose of this refactoring is first to better reflect how sending
is implemented. It will also simplify the implementation of Tx
multi-buffer per streams.
Implement qc_destroy. This callback is used to quickly release all MUX
resources.
session_free uses this callback. Currently, it can only be called if
there was an error during connection initialization. If not defined, the
process crashes.
For all muxes, the function responsible to release a mux is always called
with a defined mux. Thus there is no reason to test if it is defined or not.
Note the patch may seem huge but it is just because of indentation changes.
Several muxes (h2, fcgi, quic) don't support the protocol upgrade. For these
muxes, there is no reason to have code to support it. Thus in the destroy
callback, there is now a BUG_ON() and the release function is simplified
because the connection is always owned by the mux..
All old flags CS_FL_* are now moved in the endpoint scope and renamed
CS_EP_* accordingly. It is a systematic replacement. There is no true change
except for the health-check and the endpoint reset. Here it is a bit special
because the same conn-stream is reused. Thus, we must handle endpoint
allocation errors. To do so, cs_reset_endp() has been adapted.
Thanks to this last change, it will now be possible to simplify the
multiplexer and probably the applets too. A review must also be performed to
remove some flags in the channel or the stream-interface. The HTX will
probably be simplified too. Finally, there is now some place in the
conn-stream to move info from the stream-interface.
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.
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.
It was supposed to be there, and probably was not placed there due to
historic limitations in listener_accept(), but now there does not seem
to be a remaining valid reason for keeping the quic_conn out of the
handle. In addition in new_quic_cli_conn() the handle->fd was incorrectly
set to the listener's FD.
The mux didn't have its flags nor name set, as seen in this output of
"haproxy -vv":
Available multiplexer protocols :
(protocols marked as <default> cannot be specified using 'proto' keyword)
quic : mode=HTTP side=FE mux= flags=
h2 : mode=HTTP side=FE|BE mux=H2 flags=HTX|CLEAN_ABRT|HOL_RISK|NO_UPG
This might have random impacts at certain points like forcing some
connections to close instead of aborting a stream, or not always
handling certain streams as fully HTX-compliant.
On qc_detach(), the qcs must cleared the conn-stream context and set its
cs pointer to NULL. This prevents the qcs to point to a dangling
reference.
Without this, a SEGFAULT may occurs in qc_wake_some_streams() when
accessing an already detached conn-stream instance through a qcs.
Here is the SEGFAULT observed on haproxy.org.
Program terminated with signal 11, Segmentation fault.
1234 else if (qcs->cs->data_cb->wake) {
(gdb) p qcs.cs.data_cb
$1 = (const struct data_cb *) 0x0
This can happens since the following patch :
commit fe035eca3a24ea0f031fdcdad23809bea5de32e4
MEDIUM: mux-quic: report errors on conn-streams
The stream mux buffering has been reworked since the introduction of the
struct qc_stream_desc. A qcs is now able to quickly release its buffer
to the quic-conn.
Define a new API to notify the MUX from the quic-conn when the
connection is about to be closed. This happens in the following cases :
- on idle timeout
- on CONNECTION_CLOSE emission or reception
The MUX wake callback is called on these conditions. The quic-conn
QUIC_FL_NOTIFY_CLOSE is set to only report once. On the MUX side,
connection flags CO_FL_SOCK_RD_SH|CO_FL_SOCK_WR_SH are set to interrupt
future emission/reception.
This patch is the counterpart to
"MEDIUM: mux-quic: report CO_FL_ERROR on send".
Now the quic-conn is able to report its closing, which may be translated
by the MUX into a CO_FL_ERROR on the connection for the upper layer.
This allows the MUX to properly react to the QUIC closing mechanism for
both idle-timeout and closing/draining states.
Complete the error reporting. For each attached streams, if CO_FL_ERROR
is set, mark them with CS_FL_ERR_PENDING|CS_FL_ERROR. This will notify
the upper layer to trigger streams detach and release of the MUX.
This reporting is implemented in a new function qc_wake_some_streams(),
called by qc_wake(). This ensures that a lower-layer error is quickly
reported to the individual streams.
Mark the connection with CO_FL_ERROR on qc_send() if the socket Tx is
closed. This flag is used by the upper layer to order a close on the
MUX. This requires to check CO_FL_ERROR in qcc_is_dead() to process to
immediate MUX free when set.
The qc_wake() callback has been completed. Most notably, it now calls
qc_send() to report a possible CO_FL_ERROR. This is useful because
qc_wake() is called by the quic-conn on imminent closing.
Note that for the moment the error flag can never be set because the
quic-conn does not report when the Tx socket is closed. This will be
implemented in a following patch.
Regroup all features related to sending in qc_send(). This will be
useful when qc_send() will be called outside of the io-cb.
Currently, flow-control frames generation is now automatically
integrated in qc_send().
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.
Improve timeout handling on the MUX. When releasing a stream, first
check if the connection can be considered as dead and should be freed
immediatly. This allows to liberate resources faster when possible.
If the connection is still active, ensure there is no attached
conn-stream before scheduling the timeout. To do this, add a nb_cs field
in the qcc structure.
The new qc_stream_desc type has a tree node for storage. Thus, we can
remove the node in the qcs structure.
When initializing a new stream, it is stored into the qcc streams_by_id
tree. When the MUX releases it, it will freed as soon as its buffer is
emptied. Before this, the quic-conn is responsible to store it inside
its own streams_by_id tree.
Move the xprt-buf and ack related fields from qcs to the qc_stream_desc
structure. In exchange, qcs has a pointer to the low-level stream. For
each new qcs, a qc_stream_desc is automatically allocated.
This simplify the transport layer by removing qcs/mux manipulation
during ACK frame parsing. An additional check is done to not notify the
MUX on sending if the stream is already released : this case may now
happen on retransmission.
To complete this change, the quic_stream frame now references the
quic_stream instance instead of a qcs.
Remove qcs instances left during qcc MUX release. This can happen when
the MUX is closed before the completion of all the transfers, such as on
a timeout or process termination.
This may free some memory leaks on the connection.
Define a new callback release inside qcc_app_ops. It is called when the
qcc MUX is freed via qc_release. This will allows to implement cleaning
on the app layer.
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.
This commit is similar to the following one :
commit 118b2cbf8430a9513947c27a8403ff380e1dcaf2
MINOR: quic: activate QUIC traces at compilation
If the macro ENABLE_QUIC_STDOUT_TRACES is defined, qmux traces are
outputted automatically on stdout. This is useful for the haproxy-qns
interop docker image.
Add a new qmux trace event QMUX_EV_QCS_PUSH_FRM. Its only purpose is to
display the meaningful result of a qcs_push_frame invocation.
A dedicated struct qcs_push_frm_trace_arg is defined to pass a series of
extra args for the trace output.
Define a new qmux event QMUX_EV_SEND_FRM. This allows to pass a
quic_frame as an extra argument. Depending on the frame type, a special
format can be used to log the frame content.
Currently this event is only used in qc_send_max_streams. Thus the
handler is only able to handle MAX_STREAMS frames.
Convert all printfs in the mux-quic code with traces.
Note that some meaningul printfs were not converted because they use
extra args in a format-string. This is the case inside qcs_push_frame
and qc_send_max_streams. A dedicated trace event should be implemented
for them to be able to display the extra arguments.
Declare a new trace module for mux-quic named qmux. It will be used to
convert all printf to regular traces. The handler qmux_trace can uses a
connection and a qcs instance as extra arguments.
This commit is similar to the previous one but with MAX_DATA frames.
This allows to increase the connection level flow-control limit. If the
connection was blocked due to QC_CF_BLK_MFCTL flag, the flag is reseted.
