We modify the functions responsible of building packets to put these latters
in ring buffers (qc_build_hdshk_pkt() during the handshake step, and
qc_build_phdshk_apkt() during the post-handshake step). These functions
remove a ring buffer from its list to build as much as possible datagrams.
Eache datagram is prepended of two field: the datagram length and the
first packet in the datagram. We chain the packets belonging to the same datagram
in a singly linked list to reach them from the first one: indeed we must
modify some members of each packet when we really send them from send_ppkts().
This function is also modified to retrieved the datagram from ring buffers.
We initialize the pointer to the listener TX ring buffer list.
Note that this is not done for QUIC clients as we do not fully support them:
we only have to allocate the list and attach it to server struct I guess.
We allocate an array of QUIC ring buffer, one by thread, and arranges them in a
MT_LIST. Everything is allocated or nothing: we do not want to usse an incomplete
array of ring buffers to ensure that each thread may safely acquire one of these
buffers.
Before this patch we reserved 16 bytes (QUIC_TLS_TAG_LEN) before building the
handshake packet to be sure to be able to add the tag which comes with the
the packet encryption, decreasing the end offset of the building buffer by 16 bytes.
But this tag length was taken into an account when calling qc_build_frms() which
computes and build crypto frames for the remaining available room thanks to <*len>
parameter which is the length of the already present bytes in the building buffer
before adding CRYPTO frames. This leaded us to waste the 16 last bytes of the buffer
which were not used.
This make at least our listeners answer to ngtcp2 clients without
HelloRetryRequest message. It seems the server choses the first
group in the group list ordered by preference and set by
SSL_CTX_set1_curves_list() which match the client ones.
This implementation is inspired from Linux kernel circular buffer implementation
(see include/linux/circ-buf.h). Such buffers may be used at the same time both
by writer and reader (lock-free).
Modify the I/O dgram handler principal function used to parse QUIC packets
be thread safe. Its role is at least to create new incoming connections
add to two trees protected by the same RW lock. The packets are for now on
fully parsed before possibly creating new connections.
Allocate everything needed for a connection (struct quic_conn) from the same
function.
Rename qc_new_conn_init() to qc_new_conn() to reflect these modifications.
Insert these connection objects in their tree after returning from this function.
Some SSL call may be called with pointer to ssl_sock_ctx struct as parameter
which does not match the quic_conn_ctx struct type (see ssl_sock_infocb()).
I am not sure we have to keep such callbacks for QUIC but we must ensure
the SSL and QUIC xprts use the same data structure as context.
Move the connection state from quic_conn_ctx struct to quic_conn struct which
is the structure which is used to store the QUIC connection part information.
This structure is initialized by the I/O dgram handler for each new connection
to QUIC listeners. This is needed for the multithread support so that to not
to have to depend on the connection context potentially initialized by another
thread.
We must protect from concurrent the tree which stores the QUIC packets received
by the dgram I/O handler, these packets being also parsed by the xprt task.
No need to call free_quic_rx_packet() after calling quic_rx_packet_eb64_delete()
as this latter already calls quic_rx_packet_refdec() also called by
free_quic_rx_packet().
Let's say that we have to insert a range R between to others A and B
with A->first <= R->first <= B->first. We have to remove the ranges
which are overlapsed by R during. This was correctly done when
the intersection between A and R was not empty, but not when the
intersection between R and B was not empty. If this latter case
after having inserting a new range R we set <new> variable as the
node to consider to check the overlaping between R and its following
ranges.
Make depends qc_new_isecs() only on quic_conn struct initialization only (no more
dependency on connection struct initialization) to be able to run it as soon as
the quic_conn struct is initialized (from the I/O handler) before running ->accept()
quic proto callback.
We remove the header protection of packet only for connection with already
initialized context. This latter keep traces of the connection state.
Furthermore, we enqueue the first Initial packet for a new connection
after having completely parsed the packet so that to not start the accept
process for nothing.
Move the QUIC conn (struct quic_conn) initialization from quic_sock_accept_conn()
to qc_lstnr_pkt_rcv() as this is done for the server part.
Move the timer initialization to ->start xprt callback to ensure the connection
context is done : it is initialized by the ->accept callback which may be run
by another thread than the one for the I/O handler which also run ->start.
Move the call to SSL_set_quic_transport_params() from the listener I/O dgram
handler to the ->init() callback of the xprt (qc_conn_init()) which initializes
its context where is stored the SSL context itself, needed by
SSL_set_quic_transport_params(). Furthermore this is already what is done for the
server counterpart of ->init() QUIC xprt callback. As the ->init() may be run
by another thread than the one for the I/O handler, the xprt context could
not be potentially already initialized before calling SSL_set_quic_transport_params()
from the I/O handler.
The name the maximum packet size transport parameter was ambiguous and replaced
by maximum UDP payload size. Our code would be also ambiguous if it does not
reflect this change.
Set the streams transport parameters which could not be initialized because they
were not available during initializations. Indeed, the streams transport parameters
are provided by the peer during the handshake.
This function calls quic_mux_transport_params_update() to update the related
streams transport parameter of the mux. It is there only so that not to have
to include mux_quic.h to update these parameters.
Really signal the caller that ->accept() has failed if the session could not
be initialized because conn_complete_session() has failed. This is the case
if the mux could not be initialized too.
When it fails an ->accept() must returns -1 in case of resource shortage.
Deactivate the action of this callback at this time. I am not sure
we will keep it for QUIC as it does not really make sense for QUIC:
the QUIC packet are already recvfrom()'ed by the low level I/O handler
used for all the connections.
Add a new structure to store enough information about STREAM frames which
must be stored before being delivered to the application layer, for any
reason.
The flow control at stream level is organized by types (client bidi, server bidi,
client uni, server uni). Adds at least callback to retrieve the number
of available streams by direction.
