When an error is detected at quic-conn layer, the upper MUX must be
notified. Previously, this was done relying on quic_conn flag
QUIC_FL_CONN_NOTIFY_CLOSE set and the MUX wake callback called on
connection closure.
Adjust this mechanism to use an approach more similar to other transport
layers in haproxy. On error, connection flags are updated with
CO_FL_ERROR, CO_FL_SOCK_RD_SH and CO_FL_SOCK_WR_SH. The MUX is then
notified when the error happened instead of just before the closing. To
reflect this change, qc_notify_close() has been renamed qc_notify_err().
This function must now be explicitely called every time a new error
condition arises on the quic_conn layer.
To ensure MUX send is disabled on error, qc_send_mux() now checks
CO_FL_SOCK_WR_SH. If set, the function returns an error. This should
prevent the MUX from sending data on closing or draining state.
To complete this patch, MUX layer must now check for CO_FL_ERROR
explicitely. This will be the subject of the following commit.
This should be backported up to 2.7.
qc_treat_ack_of_ack() must remove ranges of acknowlegments from an ebtree which
have been acknowledged. This is done keeping track of the largest acknowledged
packet number which has been acknowledged and sent with an ack-eliciting packet.
But due to the data structure of the acknowledgement ranges used to build an ACK frame,
one must leave at least one range in such an ebtree which must at least contain
a unique one-element range with the largest acknowledged packet number as element.
This issue was revealed by @Tristan971 in GH #2140.
Must be backported in 2.7 and 2.6.
As noticed by Miroslav, there was a typo in quic_tls_key_update() which lead
a cipher context for decryption to be initialized and used in place of a cipher
context for encryption. Surprisingly, this did not prevent the key update
from working. Perhaps this is due to the fact that the underlying cryptographic
algorithms used by QUIC are all symetric algorithms.
Also modify incorrect traces.
Must be backported in 2.6 and 2.7.
Add a new output format "oneline" for "show quic" command. This prints
one connection per line with minimal information. The objective is to
have an equivalent of the netstat/ss tools with just enough information
to quickly find connection which are misbehaving.
A legend is printed on the first line to describe the field columns
starting with a dash character.
This should be backported up to 2.7.
Add an extra optional argument for "show quic" to specify desired output
format. Its objective is to control the verbosity per connections. For
the moment, only "full" is supported, which is the already implemented
output with maximum information.
This should be backported up to 2.7.
Each quic_conn are attached in a global thread-local quic_conns list
used for "show quic" command. During thread rebinding, a connection is
detached from its local list instance and moved to its new thread list.
However this operation is not thread-safe and may cause a race
condition.
To fix this, only remove the connection from its list inside
qc_set_tid_affinity(). The connection is inserted only after in
qc_finalize_affinity_rebind() on the new thread instance thus prevented
a race condition. One impact of this is that a connection will be
invisible during rebinding for "show quic".
A connection must not transition to closing state in between this two
steps or else cleanup via quic_handle_stopping() may not miss it. To
ensure this, this patch relies on the previous commit :
commit d6646dddccb1aae08f60717b5b6743c513c37299
MINOR: quic: finalize affinity change as soon as possible
This should be backported up to 2.7.
During accept, a quic-conn is rebind to a new thread. This process is
done in two times :
* first on the original thread via qc_set_tid_affinity()
* then on the newly assigned thread via qc_finalize_affinity_rebind()
Most quic_conn operations (I/O tasklet, task and quic_conn FD socket
read) are reactivated ony after the second step. However, there is a
possibility that datagrams are handled before it via quic_dgram_parse()
when using listener sockets. This does not seem to cause any issue but
this may cause unexpected behavior in the future.
To simplify this, qc_finalize_affinity_rebind() will be called both by
qc_xprt_start() and quic_dgram_parse(). Only one invocation will be
performed thanks to the new flag QUIC_FL_CONN_AFFINITY_CHANGED.
This should be backported up to 2.7.
Make quic_stateless_reset_token_cpy(), quic_derive_cid() and quic_get_cid_tid()
be more readable: there is no struct buffer variable manipulated by these
functions.
Should be backported to 2.7.
There is no <buf> variable passed to this function.
Also rename <buf_end> to <end> to mimic others functions.
Rename <beg> to <first_byte> and <end> to <last_byte>.
Should be backported to 2.7.
Make quic_build_packet_long_header(), quic_build_packet_short_header() and
quic_apply_header_protection() be more readable: there is no struct buffer
variables used by these functions.
Should be backported to 2.7.
Remove the pointer to the connection passed as parameters to qc_purge_tx_buf()
and other similar function which came with qc_purge_tx_buf() implementation.
They were there do track the connection during tests.
Must be backported to 2.7.
Rename all frame variables with the suffix _frm. This helps to
differentiate frame instances from other internal objects.
This should be backported up to 2.7.
Each frame type used in quic_frame union has been renamed with the
following prefix "qf_". This helps to differentiate frame instances from
other internal objects.
This should be backported up to 2.7.
From the idle_timer_task(), the I/O handler must be woken up to send ack. But
there is no reason to do that in draining state or killing state. In draining
state this is even forbidden.
Must be backported to 2.7.
The timer task responsible of triggering probing retransmission did not inspect
the state of the connection before doing its job. But there is no need to
probe the peer when the connection is in draining or killing state. About the
draining state, this is even forbidden.
Must be backported to 2.7 and 2.6.
qc_dgrams_retransmit() prepares two list of frames to be retransmitted into
two datagrams. If the first datagram could not be sent, the TX buffer will
be purged with the prepared packet and its frames, but this was not the case for
the second list of frames.
Must be backported in 2.7.
This bug arrived with this commit which was not sufficient:
BUG/MEDIUM: quic: Missing TX buffer draining from qc_send_ppkts()
Indeed, there were also remaining allocated TX packets to be released and
their TX frames.
Implement qc_purge_tx_buf() to do so which depends on qc_free_tx_coalesced_pkts()
and qc_free_frm_list().
Must be backported to 2.7.
When migrating a quic_conn to another thread, we may need to also
switch the listener if the thread belongs to another group. When
this happens, the freshly created connection will already have the
target listener, so let's just pick it from the connection and use
it in qc_set_tid_affinity(). Note that it will be the caller's
responsibility to guarantee this.
A BUG_ON crash can occur on qc_rcv_buf() if a Rx packet allocation
failed.
To fix this, datagram are marked as consumed even if a fatal error
occured during parsing. For the moment, only a Rx packet allocation
failure could provoke this. At this stage, it's unknown if the datagram
were partially parsed or not at all so it's better to discard it
completely.
This bug was detected using -dMfail argument.
This should be backported up to 2.7.
Properly initialize el_th_ctx member first on qc_new_conn(). This
prevents a segfault if release should be called later due to memory
allocation failure in the function on qc_detach_th_ctx_list().
This should be backported up to 2.7.
Again a now_ms variable value used without the ticks API. It is used
to store the generation time of the Retry token to be received back
from the client.
Must be backported to 2.6 and 2.7.
As server, an Initial does not contain a token but only the token length field
with zero as value. The remaining room was not checked before writting this field.
Must be backported to 2.6 and 2.7.
Since this commit:
BUG/MINOR: quic: Possible wrapped values used as ACK tree purging limit.
There are more chances that ack ranges may be removed from their trees when
building a packet. It is preferable to impose a limit to these trees. This
will be the subject of the a next commit to come.
For now on, it is sufficient to stop deleting ack range from their trees.
Remove quic_ack_frm_reduce_sz() and quic_rm_last_ack_ranges() which were
there to do that.
Make qc_frm_len() support ACK frames and calls it to ensure an ACK frame
may be added to a packet before building it.
Must be backported to 2.6 and 2.7.
The following commit introduced a regression :
commit 1a5cc19cecfa84bfd0fdd7b9d5d20899cce40662
MINOR: quic: adjust Rx packet type parsing
Since this commit, qv variable was left to NULL as version is stored
directly in quic_rx_packet instance. In most cases, this only causes
traces to skip version printing. However, qv is dereferenced when
sending a Retry which causes a segfault.
To fix this, simply remove qv variable and use pkt->version instead,
both for traces and send_retry() invocation.
This bug was detected thanks to QUIC interop runner. It can easily be
reproduced by using quic-force-retry on the bind line.
This must be backported up to 2.7.
When a quic_conn instance is rebinded on a new thread its tasks and
tasklet are destroyed and new ones created. Its socket is also migrated
to a new thread which stop reception on it.
To properly reactivate a quic_conn after rebind, wake up its tasks and
tasklet if they were active before thread rebind. Also reactivate
reading on the socket FD. These operations are implemented on a new
function qc_finalize_affinity_rebind().
This should be backported up to 2.7 after a period of observation.
Implement a new function qc_set_tid_affinity(). This function is
responsible to rebind a quic_conn instance to a new thread.
This operation consists mostly of releasing existing tasks and tasklet
and allocating new instances on the new thread. If the quic_conn uses
its owned socket, it is also migrated to the new thread. The migration
is finally completed with updated the CID TID to the new thread. After
this step, the connection is thus accessible to the new thread and
cannot be access anymore on the old one without risking race condition.
To ensure rebinding is either done completely or not at all, tasks and
tasklet are pre-allocated before all operations. If this fails, an error
is returned and rebiding is not done.
To destroy the older tasklet, its context is set to NULL before wake up.
In I/O callbacks, a new function qc_process() is used to check context
and free the tasklet if NULL.
The thread rebinding can cause a race condition if the older thread
quic_dghdlrs::dgrams list contains datagram for the connection after
rebinding is done. To prevent this, quic_rx_pkt_retrieve_conn() always
check if the packet CID is still associated to the current thread or
not. In the latter case, no connection is returned and the new thread is
returned to allow to redispatch the datagram to the new thread in a
thread-safe way.
This should be backported up to 2.7 after a period of observation.
When QUIC handshake is completed on our side, some frames are prepared
to be sent :
* HANDSHAKE_DONE
* several NEW_CONNECTION_ID with CIDs allocated
This step was previously executed in quic_conn_io_cb() directly after
CRYPTO frames parsing. This patch delays it to be completed after
accept. Special care have been taken to ensure it is still functional
with 0-RTT activated.
For the moment, this patch should have no impact. However, when
quic_conn thread migration on accept will be implemented, it will be
easier to remap only one CID to the new thread. New CIDs will be
allocated after migration on the new thread.
This should be backported up to 2.7 after a period of observation.
TID encoding in CID was removed by a recent change. It is now possible
to access to the <tid> member stored in quic_connection_id instance.
For unknown CID, a quick solution was to redispatch to the thread
corresponding to the first CID byte. This ensures that an identical CID
will always be handled by the same thread to avoid creating multiple
same connection. However, this forces an uneven load repartition which
can be critical for QUIC handshake operation.
To improve this, remove the above constraint. An unknown CID is now
handled by its receiving thread. However, this means that if multiple
packets are received with the same unknown CID, several threads will try
to allocate the same connection.
To prevent this race condition, CID insertion in global tree is now
conducted first before creating the connection. This is a thread-safe
operation which can only be executed by a single thread. The thread
which have inserted the CID will then proceed to quic_conn allocation.
Other threads won't be able to insert the same CID : this will stop the
treatment of the current packet which is redispatch to the now owning
thread.
This should be backported up to 2.7 after a period of observation.
CIDs were moved from a per-thread list to a global list instance. The
TID-encoded is thus non needed anymore.
This should be backported up to 2.7 after a period of observation.
Previously, quic_connection_id were stored in a per-thread tree list.
Datagram were first dispatched to the correct thread using the encoded
TID before a tree lookup was done.
Remove these trees and replace it with a global trees list of 256
entries. A CID is using the list index corresponding to its first byte.
On datagram dispatch, CID is lookup on its tree and TID is retrieved
using new member quic_connection_id.tid. As such, a read-write lock
protects each list instances. With 256 entries, it is expected that
contention should be reduced.
A new structure quic_cid_tree served as a tree container associated with
its read-write lock. An API is implemented to ensure lock safety for
insert/lookup/delete operation.
This patch is a step forward to be able to break the affinity between a
CID and a TID encoded thread. This is required to be able to migrate a
quic_conn after accept to select thread based on their load.
This should be backported up to 2.7 after a period of observation.
Remove <tid> member in quic_conn. This is moved to quic_connection_id
instance.
For the moment, this change has no impact. Indeed, qc.tid reference
could easily be replaced by tid as all of this work was already done on
the connection thread. However, it is planified to support quic_conn
thread migration in the future, so removal of qc.tid will simplify this.
This should be backported up to 2.7.
ODCID are never stored in the CID tree. Instead, we store our generated
CID which is directly derived from the CID using a hash function. This
operation is done via quic_derive_cid().
Previously, generated CID was returned as a 64-bits integer. However,
this is cumbersome to convert as an array of bytes which is the most
common CID representation. Adjust this by modifying return type to a
quic_cid struct.
This should be backported up to 2.7.
qc_parse_hd_form() is the function used to parse the first byte of a
packet and return its type and version. Its API has been simplified with
the following changes :
* extra out paremeters are removed (long_header and version). All infos
are now stored directly in quic_rx_packet instance
* a new dummy version is declared in quic_versions array with a 0 number
code. This can be used to match Version negotiation packets.
* a new default packet type is defined QUIC_PACKET_TYPE_UNKNOWN to be
used as an initial value.
Also, the function has been exported to an include file. This will be
useful to be able to reuse on quic-sock to parse the first packet of a
datagram.
This should be backported up to 2.7.
Two different structs exists for QUIC connection ID :
* quic_connection_id which represents a full CID with its sequence
number
* quic_cid which is just a buffer with a length. It is contained in the
above structure.
To better differentiate them, rename all quic_connection_id variable
instances to "conn_id" by contrast to "cid" which is used for quic_cid.
This should be backported up to 2.7.
Remove quic_conn instance as first parameter of
quic_stateless_reset_token_init() and quic_stateless_reset_token_cpy()
functions. It was only used for trace purpose.
The main advantage is that it will be possible to allocate a QUIC CID
without a quic_conn instance using new_quic_cid() which is requires to
first check if a CID is existing before allocating a connection.
This should be backported up to 2.7.
As revealed by GH #2120 opened by @Tristan971, there are cases where ACKs
have to be sent without packet to acknowledge because the ACK timer has
been triggered and the connection needs to probe the peer at the same time.
Indeed
Thank you to @Tristan971 for having reported this issue.
Must be backported to 2.6 and 2.7.
This bug arrived with this commit:
MEDIUM: quic: Ack delay implementation
After having probed the Handshake packet number space, one must not select the
Application encryption level to continue trying building packets as this is done
when the connection is not probing. Indeed, if the ACK timer has been triggered
in the meantime, the packet builder will try to build a packet at the Application
encryption level to acknowledge the received packet. But there is very often
no 01RTT packet to acknowledge when the connection is probing before the
handshake is completed. This triggers a BUG_ON() in qc_do_build_pkt() which
checks that the tree of ACK ranges to be used is not empty.
Thank you to @Tristan971 for having reported this issue in GH #2109.
Must be backported to 2.6 and 2.7.
