The STREAM data to send coming from the upper layer must be stored until
having being acked by the peer. To do so, we store them in buffer structs,
one by stream (see qcs.tx.buf). Each time a STREAM is built by quic_push_frame(),
its offset must match the offset of the first byte added to the buffer (modulo
the size of the buffer) by the frame. As they are not always acknowledged in
order, they may be stored in eb_trees ordered by their offset to be sure
to sequentially delete the STREAM data from their buffer, in the order they
have been added to it.
These structures are similar. quic_tx_frm was there to try to reduce the
size of such objects which embed a union for all the QUIC frames.
Furtheremore this patch fixes the issue where quic_tx_frm objects were freed
from the pool for quic_frame.
If we let the connection packet handler task (quic_conn_io_cb) process the first
client Initial packet which contain the TLS Client Hello message before the mux
context is initialized, quic_mux_transport_params_update() makes haproxy crash.
->start xprt callback already wakes up this task and is called after all the
connection contexts are initialized. So, this patch do not wakes up quic_conn_io_cb()
if the mux context is not initialized (this was already the case for the connection
context (conn_ctx)).
This file has been derived from mux_h2.c removing all h2 parts. At
QUIC mux layer, there must not be any reference to http. This will be the
responsability of the application layer (h3) to open streams handled by the mux.
