We must take as most as possible data from STREAM frames to be encapsulated
in QUIC packets, almost as this is done for CRYPTO frames whose fields are
variable length fields. The difference is that STREAM frames are only accepted
for short packets without any "Length" field. So it is sufficient to call
max_available_room() for that in place of max_stream_data_size() as this
is done for CRYPTO data.
It is possible the TLS stack stack provides us with 1-RTT TX secrets
at the same time as Handshake secrets are provided. Thanks to this
simple patch we can build Application level packets during the handshake.
Make qc_prep_hdshk_pkts() and qui_conn_io_cb() handle the case
where we enter them with QUIC_HS_ST_COMPLETE or QUIC_HS_ST_CONFIRMED
as connection state with QUIC_TLS_ENC_LEVEL_APP and QUIC_TLS_ENC_LEVEL_NONE
to consider to prepare packets.
quic_get_tls_enc_levels() is modified to return QUIC_TLS_ENC_LEVEL_APP
and QUIC_TLS_ENC_LEVEL_NONE as levels to consider when coalescing
packets in the same datagram.
With very few packets received by the listener, it is possible
that its state may move from QUIC_HS_ST_SERVER_INITIAL to
QUIC_HS_ST_COMPLETE without transition to QUIC_HS_ST_SERVER_HANDSHAKE state.
This latter state is not mandatory.
This simple enable use to coalesce Application level packet with
Handshake ones at the end of the handshake. This is highly useful
if we do want to send a short Handshake packet followed by Application
level ones.
qc_build_pkt() has recently been modified to support any type of
supported frame at any encryption level (assuming that an encryption level does
not support any type of frame) but quic_tls_level_pkt_type()
prevented it from building application level packet type because it was written
only for the handshake.
This patch simply adds the remaining encryption level QUIC_TLS_ENC_LEVEL_APP
which must be supported by quic_tls_level_pkt_type().
We must evaluate the packet lenghts in advance to be sure we do not
consume a packet number for nothing. The packet building must always
succeeds. This is the role of qc_eval_pkt() implemented by this patch
called before calling qc_do_build_pkt() which was previously modified to
always succeed.
There were cases where the encoded size of acks was not updated leading
to ACK frames building too big compared to the expected size. At this
time, this makes the code "BUG_ON()".
Rename qc_build_hdshk_pkt() to qc_build_pkt() and qc_do_build_hdshk_pkt()
to qc_do_build_pkt().
Update their comments consequently.
Make qc_do_build_hdshk_pkt() BUG_ON() when it does not manage to build
a packet. This is a bug!
Remove the functions which were specific to the Application level.
This is the same function which build any packet for any encryption
level: quic_prep_hdshk_pkts() directly called from the quic_conn_io_cb().
There is no need to pass a copy of CRYPTO frames to qc_build_frm() from
qc_do_build_hdshk_pkt(). Furthermore, after the previous modifications,
qc_do_build_hdshk_pkt() do not build only CRYPTO frame from ->pktns.tx.frms
MT_LIST but any type of frame.
Atomically increase the "next packet variable" before building a new packet.
Make the code bug on a packet building failure. This should never happen
if we do not want to consume a packet number for nothing. There are remaining
modifications to come to ensure this is the case.
Modify this task which is called at least each a packet is received by a listener
so that to make it behave almost as qc_do_hdshk(). This latter is no more useful
and removed.
This function was responsible of building CRYPTO frames to fill as much as
possible a packet passed as argument. This patch makes it support any frame
except STREAM frames whose lengths are highly variable.
We want to treat all the frames to be built the same way as frames
built during handshake (CRYPTO frames). So, let't store them at the same
place which is an MT_LIST.
This should be used by the function which build packets to prevent
it from failing. This is important when the packet numbers are consumed
by several threads. The packet number is used to build and encrypt packets
and must be incremented only and only if the packet it refers to has been
successfully built.
As this has been done for RX frame parsers, we add a mask for each TX frame
builder to denote the packet types which are authorized to embed such frames.
Each time a TX frame builder is called, we check that its mask matches the
packet type the frame is built for.
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.
Make quic_rx_packet_ref(inc|dec)() functions be thread safe.
Make use of ->rx.crypto.frms_rwlock RW lock when manipulating RX frames
from qc_treat_rx_crypto_frms().
Modify atomically several variables attached to RX part of quic_enc_level struct.
->rx.crypto member of quic_enc_level struct was not initialized as
this was done for all other members of this structure. This patch
fixes this.
Also adds a RW lock for the frame of this member.
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)).
If we add TX packets to their trees before sending them, they may
be detected as lost before being sent. This may make haproxy crash
when it retreives the prepared packets from TX ring buffers, dereferencing
them after they have been freed.
Add two functions to encrement or decrement a referenc counter
attached to TX packet structure (struct quic_tx_packet). The packet are freed
when their counters reach the null value.
We use only ring buffers (struct qring) to prepare and send QUIC datagrams.
We can safely remove the old buffering implementation which was not thread safe.
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).
