We establish the persistent congestion out of any congestion controller
to improve the algorithms genericity. This path characteristic detection may
be implemented regarless of the underlying congestion control algorithm.
Send congestion (loss) event using directly quic_cc_event(), so without
qc_cc_loss_event() wrapper function around quic_cc_event().
Take the opportunity of this patch to shorten "newest_time_sent" member field
of quic_cc_event to "time_sent".
QUIC connection path in flight bytes is a variable which should not be manipulated
by the congestion controller. This latter aim is to compute the congestion window.
So, we pass it as less as parameters as possible to do so.
Since QUIC accept handling has been improved, the MUX is initialized
after the handshake completion. Thus its safe to access transport
parameters in qc_init via the quic_conn.
Remove quic_mux_transport_params_update which was called by the
transport for the MUX. This improves the architecture by removing a
direct call from the transport to the MUX.
The deleted function body is not transfered to qc_init because this part
will change heavily in the near future when implementing the
flow-control.
We want to be able to build ack-eliciting frames to be embedded into QUIC packets
from a prebuilt list of ack-eliciting frames. This will be helpful for the mux
which would like to send STREAM frames asap after having builts its own prebuilt
list.
To do so, we only add a parameter as struct list to this function to handle
such a prebuilt list.
We want to be able to send ack-elicting packets from a list of ack-eliciting
frames. So, this patch adds such a paramaters to the function responsible of
building 1RTT packets. The entry point function is qc_send_app_pkts() which
is used with the underlying packet number space TX frame list as parameter.
We want to get rid of the code used during the handshake step. qc_prep_app_pkts()
aim is to build short packets which are also datagrams.
Make quic_conn_app_io_cb() call this new function to prepare short packets.
As reported by Tim in issue #1428, our sources are clean, there are
just a few files with a few rare non-ASCII chars for the paragraph
symbol, a few typos, or in Fred's name. Given that Fred already uses
the non-accentuated form at other places like on the public list,
let's uniformize all this and make sure the code displays equally
everywhere.
A segfault happens when receiving a CONNECTION_CLOSE during handshake.
This is because the mux is not initialized at this stage but the
transport layer dereferences it.
Fix this by ensuring that the MUX is initialized before. Thanks to Willy
for his help on this one. Welcome in the QUIC-men team !
Do not distinguish the direction (TX/RX) when settings TLS secrets flags.
There is not such a distinction in the RFC 9001.
Assemble them at the same level: at the upper context level.
This is required since this previous commit:
"MINOR: quic: Post handshake I/O callback switching"
If not, such packets remain endlessly in the RX buffer and cannot be parsed
by the new I/O callback used after the handshake has been confirmed.
Wakeup asap the timer task when setting its timer in the past.
Take also the opportunity of this patch to make simplify quic_pto_pktns():
calling tick_first() is useless here to compare <lpto> with <tmp_pto>.
Reorganize the Rx path for STREAM frames on bidirectional streams. A new
function qcc_recv is implemented on the MUX. It will handle the STREAM
frames copy and offset calculation from transport to MUX.
Another function named qcc_decode_qcs from the MUX can be called by
transport each time new STREAM data has been copied.
The architecture is now cleaner with the MUX layer in charge of parsing
the STREAM frames offsets. This is required to be able to implement the
flow-control on the MUX layer.
Note that as a convenience, a STREAM frame is not partially copied to
the MUX buffer. This simplify the implementation for the moment but it
may change in the future to optimize the STREAM frames handling.
For the moment, only bidirectional streams benefit from this change. In
the future, it may be extended to unidirectional streams to unify the
STREAM frames processing.
FIN flag on a STREAM frame was not detected if the frame was previously
buffered on qcs.rx.frms before being handled.
To fix this, copy the fin field from the quic_stream instance to
quic_rx_strm_frm. This is required to properly notify the FIN flag on
qc_treat_rx_strm_frms for the MUX layer.
Without this fix, the request channel might be left opened after the
last STREAM frame reception if there is out-of-order frames on the Rx
path.
This flag is set when the STREAM frame with FIN set has been received on
a qcs instance. For now, this is only used as a BUG_ON guard to prevent
against multiple frames with FIN set. It will also be useful when
reorganize the RX path and move some of its code in the mux.
Adjust the function to handle buffered STREAM frames. If the offset of
the frame was already fully received, discard the frame. If only
partially received, compute the difference and copy only the newly
offset.
Before this change, a buffered frame representing a fully or partially
received offset caused the loop to be interrupted. The frame was
preserved, thus preventing frames with greater offset to be handled.
This may fix some occurences of stalled transfer on the request channel
if there is out-of-order STREAM frames on the Rx path.
qc_strm_cpy can be simplified by simply using b_putblk which already
handle wrapping of the destination buffer. The function is kept to
update the frame length and offset fields.
The quic_frame instance containing the quic_stream must be freed when
the corresponding ACK has been received. However when implementing this
on qcs_try_to_consume, some data transfers are interrupted and cannot
complete (DC test from interop test suite).
The sending buffer of each stream is cleared when processing ACKs
corresponding to STREAM emitted frames. If the buffer is empty, free it
and offer it as with other dynamic buffers usage.
This should reduce memory consumption as before an opened stream
confiscate a buffer during its whole lifetime even if there is no more
data to transmit.
Simplify the data manipulation of STREAM frames on TX. Only stream data
and len field are used to generate a valid STREAM frames from the
buffer. Do not use the offset field, which required that a single buffer
instance should be shared for every frames on a single stream.
Adjust the handling of ACK for STREAM frames. When receiving a ACK, the
corresponding frames from the acknowledged packet are retrieved. If a
frame is of type STREAM, we compare the frame STREAM offset with the
last offset known of the qcs instance.
The comparison was incomplete as it did not treat a acked offset smaller
than the known offset. Previously, the acked frame was incorrectly
buffered in the qcs.tx.acked_frms. On reception of future ACKs, when
trying to process the buffered acks via qcs_try_to_consume, the loop is
interrupted on the smallest offset different from the qcs known offset :
in this case it will be the previous smaller range. This is a real bug
as it prevents all buffered ACKs to be processed, eventually filling the
qcs sending buffer and cause the transfer to stall.
Fix this by properly properly handle smaller acked offset. First check
if the offset length is greater than the qcs offset and mark as
acknowledged the difference on the qcs. If not, the frame is not
buffered and simply ignored.
The recent changes was not complete.
d1c76f24fdf1cfb85e574cb1ef0c773b74bee32a
MINOR: quic: do not modify offset node if quic_rx_strm_frm in tree
The frame length and data pointer should incremented after the data
copy. A BUG_ON statement has been added to detect an incorrect decrement
operaiton.
qc_rx_strm_frm_cpy is unsafe because it updates the offset field of the
frame. This is not safe as the frame is inserted in the tree when
calling this function and offset serves as the key node.
To fix this, the API is modified so that qc_rx_strm_frm_cpy does not
update the frame parameter. The caller is responsible to update
offset/length in case of a partial copy.
The impact of this bug is not known. It can only happened with received
STREAM frames out-of-order. This might be triggered with large h3 POST
requests.
Remove this server specific code section. It is useless, not tested. Furthermore
this is really not the good place to retrieve the peer transport parameters.
If the last frame is not entirely copied and must be buffered, FIN
must not be signaled to the upper layer.
This might fix a rare bug which could cause the request channel to be
closed too early leading to an incomplete request.
If a CONNECTION_CLOSE is received during handshake or after mux release,
a segfault happens due to invalid dereferencement of qc->qcc. Check
mux_state first to prevent this.
Move the QUIC datagram handlers oustide of the receivers. Use a global
handler per-thread which is allocated on post-config. Implement a free
function on process deinit to avoid a memory leak.
This should fix Coverity CID 375047 in GH #1536 where <buf_area> could leak because
not always freed by by quic_conn_drop(), especially when not stored in <qc> variable.
Rename quic_conn_to_buf to qc_snd_buf and remove it from xprt ops. This
is done to reflect the true usage of this function which is only a
wrapper around sendto but cannot be called by the upper layer.
qc_snd_buf is moved in quic-sock because to mark its link with
quic_sock_fd_iocb which is the recvfrom counterpart.
Rename a local variable tid to cid_tid. This ensures there is no
confusion with the global tid. It is now more explicit that we are
manipulating a quic datagram handlers from another thread in
quic_lstnr_dgram_dispatch.
In fact the xprt_ctx of the connection is first stored into quic_conn
struct as soon as it is initialized from qc_conn_alloc_ssl_ctx().
As quic_conn_init_timer() is run after this function, we can associate
the timer context of the timer to the one from the quic_conn struct.
We must move this initialization from xprt_start() callback, which
comes too late (after handshake completion for 1RTT session). This timer must be
usable as soon as we have packets to send/receive. Let's initialize it after
the TLS context is initialized in qc_conn_alloc_ssl_ctx(). This latter function
initializes I/O handler task (quic_conn_io_cb) to send/receive packets.
