Implement quic_tls_rx_hp_ctx_init() and quic_tls_tx_hp_ctx_init() to initiliaze
such header protection cipher contexts for each RX and TX parts and for each
packet number spaces, only one time by connection.
Make qc_new_isecs() call these two functions to initialize the cipher contexts
of the Initial secrets. Same thing for ha_quic_set_encryption_secrets() to
initialize the cipher contexts of the subsequent derived secrets (ORTT, 1RTT,
Handshake).
Modify qc_do_rm_hp() and quic_apply_header_protection() to reuse these
cipher contexts.
Note that there is no need to modify the key update for the header protection.
The header protection secrets are never updated.
This wrong trace came with this commit:
"BUG/MINOR: quic: Possible crashes when dereferencing ->pkt quic_frame struct member"
In qc_release_frm() we mark frames as acked. Nothing to see with references
to frames.
Thank you to Willy for having caught this one.
Must be backported to 2.6 as these traces arrived with a bug fix to be backported
to 2.6.
When duplicated frames are splitted, we must propagate this information
to the new allocated frame and add a reference to this new frame
to the reference list of the original frame.
Must be backported to 2.6
This was done at several places. First in qc_requeue_nacked_pkt_tx_frms.
This aim of this function is, if needed, to requeue all the TX frames of a lost
<pkt> packet passed as argument and detach them from this packet they have been
sent from. They are possible cases where the frm->pkt quic_frame struct member could
be NULL, as a result of a duplication of an original frame by qc_dup_pkt_frms(). This
function adds the duplicated frame to the original frame reference list:
LIST_APPEND(&origin->reflist, &dup_frm->ref);
But, in this function, the packet which contains the frame is the one which is passed
as argument (for debug purpose). So let us prefer using this variable.
Also do not dereference this ->pkt quic_frame member in qc_release_frm() and
qc_frm_unref() and add a trace to catch the frame with a null ->pkt member.
They are logically frames which have not already been sent.
Thank you to Tristan for having reported such crashes in GH #1808.
Must be backported to 2.6
MUX notification on TX has been edited recently : it will be notified
only when sending its own data, and not for example on retransmission by
the quic-conn layer. This is subject of the patch :
b29a1dc2f4a334c1c7fea76c59abb4097422c05c
BUG/MINOR: quic: do not notify MUX on frame retransmit
A new flag QUIC_FL_CONN_RETRANS_LOST_DATA has been introduced to
differentiate qc_send_app_pkts invocation by MUX and directly by the
quic-conn layer in quic_conn_app_io_cb(). However, this is a first
problem as internal quic-conn layer usage is not limited to
retransmission. For example for NEW_CONNECTION_ID emission.
Another problem much important is that send functions are also called
through quic_conn_io_cb() which has not been protected from MUX
notification. This could probably result in crash when trying to notify
the MUX.
To fix both problems, quic-conn flagging has been inverted : when used
by the MUX, quic-conn is flagged with QUIC_FL_CONN_TX_MUX_CONTEXT. To
improve the API, MUX must now used qc_send_mux which ensure the flag is
set. qc_send_app_pkts is now static and can only be used by the
quic-conn layer.
This must be backported wherever the previously mentionned patch is.
When duplication frames in qc_dup_pkt_frms(), ->pkt member was not correctly
initialized (copied from the original frame). This could not have any impact
because this member is initialized whe the frame is added to a packet.
This was also the case for ->flags.
Also replace the pool_zalloc() call by a call to pool_alloc().
Must be backported to 2.6.
On STREAM emission, quic-conn notifies MUX through a callback named
qcc_streams_sent_done(). This also happens on retransmission : in this
case offset are examined and notification is ignored if already seen.
However, this behavior has slightly changed since
e53b489826ba9760a527b461095402ca05d2b6be
BUG/MEDIUM: mux-quic: fix server chunked encoding response
Indeed, if offset diff is NULL, frame is now not ignored. This is to
support FIN notification with a final empty STREAM frame. A side-effect
of this is that if the last stream frame is retransmitted, it won't be
ignored in qcc_streams_sent_done().
In most cases, this side-effect is harmless as qcs instance will soon be
freed after being closed. But if qcs is still alive, this will cause a
BUG_ON crash as it is considered as locally closed.
This bug depends on delay condition and seems to be extremely rare. But
it might be the reason for a crash seen on interop with s2n client on
http3 testcase :
FATAL: bug condition "qcs->st == QC_SS_CLO" matched at src/mux_quic.c:372
call trace(16):
| 0x558228912b0d [b8 01 00 00 00 c6 00 00]: main-0x1c7878
| 0x558228917a70 [48 8b 55 d8 48 8b 45 e0]: qcc_streams_sent_done+0xcf/0x355
| 0x558228906ff1 [e9 29 05 00 00 48 8b 05]: main-0x1d3394
| 0x558228907cd9 [48 83 c4 10 85 c0 0f 85]: main-0x1d26ac
| 0x5582289089c1 [48 83 c4 50 85 c0 75 12]: main-0x1d19c4
| 0x5582288f8d2a [48 83 c4 40 48 89 45 a0]: main-0x1e165b
| 0x5582288fc4cc [89 45 b4 83 7d b4 ff 74]: qc_send_app_pkts+0xc6/0x1f0
| 0x5582288fd311 [85 c0 74 12 eb 01 90 48]: main-0x1dd074
| 0x558228b2e4c1 [48 c7 c0 d0 60 ff ff 64]: run_tasks_from_lists+0x4e6/0x98e
| 0x558228b2f13f [8b 55 80 29 c2 89 d0 89]: process_runnable_tasks+0x7d6/0x84c
| 0x558228ad9aa9 [8b 05 75 16 4b 00 83 f8]: run_poll_loop+0x80/0x48c
| 0x558228ada12f [48 8b 05 aa c5 20 00 48]: main-0x256
| 0x7ff01ed2e609 [64 48 89 04 25 30 06 00]: libpthread:+0x8609
| 0x7ff01e8ca163 [48 89 c7 b8 3c 00 00 00]: libc:clone+0x43/0x5e
To reproduce it locally, code was artificially patched to produce
retransmission and avoid qcs liberation.
In order to fix this and avoid future class of similar problem, the best
way is to not call qcc_streams_sent_done() to notify MUX for
retranmission. To implement this, we test if any of
QUIC_FL_CONN_RETRANS_OLD_DATA or the new flag
QUIC_FL_CONN_RETRANS_LOST_DATA is set. A new wrapper
qc_send_app_retransmit() has been added to set the new flag as a
complement to already existing qc_send_app_probing().
This must be backported up to 2.6.
Adjust qc_send_app_pkts function : remove <old_data> arg and provide a
new wrapper function qc_send_app_probing() which should be used instead
when probing with old data.
This simplifies the interface of the default function, most notably for
the MUX which does not interfer with retransmission.
QUIC_FL_CONN_RETRANS_OLD_DATA flag is set/unset directly in the wrapper
qc_send_app_probing().
At the same time, function documentation has been updated to clarified
arguments and return values.
This commit will be useful for the next patch to differentiate MUX and
retransmission send context. As a consequence, the current patch should
be backported wherever the next one will be.
Replace a plain '=' operator by '|=' when setting quic_frame
QUIC_FL_TX_FRAME_LOST flag.
For the moment, this change has no impact as only two exclusive flags
are defined for quic_frame. On the edited code path we are certain that
QUIC_FL_TX_FRAME_ACKED is not set due to a previous if statement, so a
plain equal or a binary OR is strictly identical.
This change will be useful if new flags are defined for quic_frame in
the future. These new flags won't be resetted automatically thanks to
binary OR without explictly intended, which otherwise could easily lead
to new bugs.
This bug came with this big commit:
"MEDIUM: quic: xprt traces rework"
This is the <ret> variable value which must be returned by most of the xprt functions.
This leaded packets which could not be decrypted to be parsed, with weird frames
to be parsed as found by Tristan in GH #1808.
To be backported where the commit above was backported.
When building an ack-eliciting frame only packet, if we did not manage to add
at least one such a frame to the packet, we did not notify the caller about
the fact the packet is empty. This could lead the caller to believe
everything was ok and make it endlessly try to build packet again and again.
This issue was amplified by the recent changes where a while(1) loop has been
added to qc_send_app_pkt() which calls qc_do_build_pkt() through qc_prep_app_pkts()
until we could not prepare packets. Before this recent change, I guess only
one empty packet was sent.
This patch checks that non empty packets could be built by qc_do_build_pkt()
and makes this function return an error if this was the case. Also note that
such an issue could happened only when the packet building was limited by
the congestion control.
Thank you to Tristan for having reported this issue in GH #1808.
Must be backported to 2.6.
This commit was not complete:
"BUG/MEDIUM: quic: Possible use of uninitialized <odcid>
variable in qc_lstnr_params_init()"
<token_odcid> should have been directly passed to qc_lstnr_params_init()
without dereferencing it to prevent haproxy to have new chances to crash!
Must be backported to 2.6.
When receiving a token into a client Initial packet without a cluster secret defined
by configuration, the <odcid> variable used to parse the ODCID from the token
could be used without having been initialized. Such a packet must be dropped. So
the sufficient part of this patch is this check:
+ }
+ else if (!global.cluster_secret && token_len) {
+ /* Impossible case: a token was received without configured
+ * cluster secret.
+ */
+ TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT,
+ NULL, NULL, NULL, qv);
+ goto drop;
}
Take the opportunity of this patch to rework and make it more readable this part
of code where such a packet must be dropped removing the <check_token> variable.
When an ODCID is parsed from a token, new <token_odcid> new pointer variable
is set to the address of the parsed ODCID. This way, is not set but used it will
make crash haproxy. This was not always the case with an uninitialized local
variable.
Adapt the API to used such a pointer variable: <token> boolean variable is removed
from qc_lstnr_params_init() prototype.
This must be backported to 2.6.
This loop is due to the fact that we do not select the next node before
the conditional "continue" statement. Furthermore the condition and the
"continue" statement may be removed after replacing eb64_first() call
by eb64_lookup_ge(): we are sure this condition may not be satisfied.
Add some comments: this function initializes connection IDs with sequence
number 1 upto <max> non included.
Take the opportunity of this patch to remove a "return" wich broke this
traces rule: for any function, do not call TRACE_ENTER() without TRACE_LEAVE()!
Add also TRACE_ERROR() for any encoutered errors.
Must be backported to 2.6
This lock was there be able to handle the RX packets for a connetion
from several threads. This is no more needed since a QUIC connection
is always handled by the same thread.
May be backported to 2.6
Add a least as much as possible TRACE_ENTER() and TRACE_LEAVE() calls
to any function. Note that some functions do not have any access to the
a quic_conn argument when receiving or parsing datagram at very low level.
Fred managed to reproduce a crash showing a corrupted accept_list when
firing thousands of concurrent picoquicdemo clients to a same instance.
It may happen if the connection was placed into the accept_list and
immediately closed before being processed (e.g. on error or t/o ?).
In any case the quic_conn_release() function should always detach a
connection to be deleted from any list, like it does for other lists,
so let's add an MT_LIST_DELETE() here.
This should be backported to 2.6.
When arriving at the handshake completion, next encryption level will be
null on quic_conn_io_cb(). Thus this must be check this before
dereferencing it via qc_need_sending() to prevent a crash.
This was reproduced quickly when browsing over a local nextcloud
instance through QUIC with firefox.
This has been introduced in the current dev with quic-conn Tx
refactoring. No need to backport it.
Check on quic_conn_io_cb() if sending is required. This allows to skip
over Tx buffer allocation if not needed.
To implement this, we check if frame lists on current and next
encryption level are empty. We also need to check if there is no need to
send ACK, PROBE or CONNECTION_CLOSE. This has been isolated in a new
function qc_need_sending() which may be reuse in some other functions in
the future.
This is the final patch on quic-conn Tx refactor. Extend the function
which is used to write a datagram header to save at the same time
written buffer data. This makes sense as the two operations are used at
the same occasion when a pre-written datagram is comitted.
Complete refactor of quic-conn Tx buffer. The buffer is now released
on every send operation completion. This should help to reduce memory
footprint as now Tx buffers are allocated and released on demand.
To simplify allocation/free of quic-conn Tx buffer, two static functions
are created named qc_txb_alloc() and qc_txb_release().
On first prototype version of QUIC, emission was multithreaded. To
support this, a custom thread-safe ring-buffer has been implemented with
qring/cbuf.
Now the thread model has been adjusted : a quic-conn is always used on
the same thread and emission is not multi-threaded. Thus, qring/cbuf
usage can be replace by a standard struct buffer.
The code has been simplified even more as for now buffer is always
drained after a prepare/send invocation. This is the case since a
datagram is always considered as sent even on sendto() error. BUG_ON
statements guard are here to ensure that this model is always valid.
Thus, code to handle data wrapping and consume too small contiguous
space with a 0-length datagram is removed.
After removing the packet header protection, we can check the packet is long
enough to contain a 16 bytes length AEAD TAG (at this end of the packet).
This test was missing.
Must be backported to 2.6.
These traces about the available room into the packet currently built and
its payload length could be displayed for each STREAM frame, even for
those which have no chance to be embedded into a packet leading to
very traces to be displayed from a connection with a lot of stream.
This was revealed by traces provide by Tristan in GH #1808
May be backported to 2.6.
When entering this function, we first check the packet length is not too short.
But this was done against the datagram lenght in place of the packet length.
This could lead to the header protection to be removed using data past
the end of the packet (without buffer overflow).
Use the packet length in place of the datagram length which is at <end>
address passed as parameter to this function. As the packet length
is already stored in ->len packet struct member, this <end> parameter is no
more useful.
Must be backported to 2.6.
The function processes packets sent by other threads in the current
thread's queue. But if, for any reason, other threads write faster
than the current one processes, this can lead to a situation where
the function never returns.
It seems that it might be what's happening in issue #1808, though
unfortunately, this function is one of the rare without traces. But
the amount of calls to functions like qc_lstnr_pkt_rcv() on a single
thread seems to indicate this possibility.
Thanks to Tristan for his efforts in collecting extremely precious
traces!
This likely needs to be backported to 2.6.
qc_snd_buf() returns an error if sendto has failed. On standard
conditions, we should check for EAGAIN/EWOULDBLOCK errno and if so,
register the file-descriptor in the poller to retry the operation later.
However, quic_conn uses directly the listener fd which is shared for all
QUIC connections of this listener on several threads. Thus, it's
complicated to implement fd supversion via the poller : there is no
mechanism to easily wakeup quic_conn or MUX after a sendto failure.
A quick and simple solution for the moment is to considered a datagram
as properly emitted even on sendto error. In the end, this will trigger
the quic_conn retransmission timer as data will be considered lost on
the network and the send operation will be retried. This solution will
be replaced when fd management for quic_conn is reworked.
In fact, this quick hack was already in use in the current code, albeit
not voluntarily. This is due to a bug caused by an API mismatch on the
return type of qc_snd_buf() which never emits a negative error code
despite its documentation. Thus, all its invocation were considered as a
success. If this bug was fixed, the sending would would have been
interrupted by a break which could cause the transfer to freeze.
qc_snd_buf() invocation is clean up : the break statement is removed.
Send operation is now always explicitely conducted entirely even on
error and buffer data is purged.
A simple optimization has been added to skip over sendto when looping
over several datagrams at the first sendto error. However, to properly
function, it requires a fix on the return type of qc_snd_buf() which is
provided in another patch.
As the behavior before and after this patch seems identical, it is not
labelled as a BUG. However, it should be backported for cleaning
purpose. It may also have an impact on github issue #1808.
The dgram length check in quic_get_dgram_dcid() rejects datagrams
matching exactly the minimum allowed length, which doesn't seem
correct. I doubt any useful packet would be that small but better
fix this to avoid confusing debugging sessions in the future.
This might be backported to 2.6.
The decrement was missing in quic_pktns_tx_pkts_release() called each time a
packet number space is discarded. This is not sure this bug could have an impact
during handshakes. This counter is used to cancel the timer used both for packet
detection and PTO, setting its value to null. So there could be retransmissions
or probing which could be triggered for nothing.
Must be backported to 2.6.
Add a loop into this function to send more packets from this function
which is called by the mux. It is broken when we could not prepare
packet with qc_prep_app_pkts() due to missing available room in the
buffer used to send packets. This improves the throughput.
Must be backported to 2.6.
As it could be interesting to be able to choose the QUIC control congestion
algorithm to be used by listener, add "quic-cc-algo" new keyword to do so.
Update the documentation consequently.
Must be backported to 2.6.
As specified by RFC 9000, it is forbidden to send a CONNECTION_CLOSE of
type 0x1d (CONNECTION_CLOSE_APP) in an Initial or Handshake packet. It
must be converted to type 0x1c (CONNECTION_CLOSE) with APPLICATION_ERROR
code.
CONNECTION_CLOSE_APP are generated by QUIC MUX interaction. Thus,
special care must be taken when dealing with a 0-RTT packet, as this is
the only case where the MUX can be instantiated and quic-conn still on
the Initial or Handshake encryption level.
To enforce RFC 9000, xprt build packet function is now responsible to
translate a CONNECTION_CLOSE_APP if still on Initial/Handshake
encryption. This process is done in a dedicated function named
qc_build_cc_frm().
Without this patch, BUG_ON() statement in qc_build_frm() will be
triggered when building a CONNECTION_CLOSE_APP frame on Initial or
Handshake level. This is because QUIC_FT_CONNECTION_CLOSE_APP frame
builder mask does not allow these encryption levels, as opposed to
QUIC_FT_CONNECTION_CLOSE builder. This crash was reproduced by modifying
the H3 layer to force emission of a CONNECTION_CLOSE_APP on first frame
of a 0-RTT session.
Note however that CONNECTION_CLOSE emission during Handshake is a
complicated process for the server. For the moment, this is still
incomplete on haproxy side. RFC 9000 requires to emit it multiple times
in several packets under different encryption levels, depending on what
we know about the client encryption context.
This patch should be backported up to 2.6.
Send a CONNECTION_CLOSE if the MUX has been released and all STREAM data
are acknowledged. This is useful to prevent a client from trying to use
a connection which have the upper layer closed.
To implement this a new function qc_check_close_on_released_mux() has
been added. It is called on QUIC MUX release notification and each time
a qc_stream_desc has been released.
This commit is associated with the previous one :
MINOR: mux-quic/h3: schedule CONNECTION_CLOSE on app release
Both patches are required to prevent the risk of browsers stuck on
webpage loading if MUX has been released. On CONNECTION_CLOSE reception,
the client will reopen a new QUIC connection.
Define a new structure quic_err to abstract a QUIC error type. This
allows to easily differentiate a transport and an application error
code. This simplifies error transmission from QUIC MUX and H3 layers.
This new type is defined in quic_frame module. It is used to replace
<err_code> field in <quic_conn>. QUIC_FL_CONN_APP_ALERT flag is removed
as it is now useless.
Utility functions are defined to be able to quickly instantiate
transport, tls and application errors.
Reception is disabled as soon as a CONNECTION_CLOSE emission is
required. An early return is done on qc_lstnr_pkt_rcv() to implement
this.
This condition is not functional if the error code sent is NO_ERROR
(0x00). To fix this, check the quic-conn flags instead of the
error code.
Currently this bug has no impact has NO_ERROR emission is not used.
This can be backported up to 2.6.
Implement support for STOP_SENDING frame parsing. The stream is resetted
as specified by RFC 9000. This will automatically interrupt all future
send operation in qc_send(). A RESET_STREAM will be sent with the code
extracted from the original STOP_SENDING frame.
MAX_STREAM_DATA can be used as the first frame of a stream. In this
case, the stream should be opened, if it respects flow-control limit. To
implement this, simply replace plain lookup in stream tree by
qcc_get_qcs() at the start of the parsing function. This automatically
takes care of opening the stream if not already done.
As specified by RFC 9000, if MAX_STREAM_DATA is receive for a
receive-only stream, a STREAM_STATE_ERROR connection error is emitted.
First we add a loop around recfrom() into the most low level I/O handler
quic_sock_fd_iocb() to collect as most as possible datagrams before during
its tasklet wakeup with a limit: we recvfrom() at most "maxpollevents"
datagrams. Furthermore we add a local task list into the datagram handler
quic_lstnr_dghdlr() which is passed to the first datagrams parser qc_lstnr_pkt_rcv().
This latter parser only identifies the connection associated to the datagrams then
wakeup the highest level packet parser I/O handlers (quic_conn.*io_cb()) after
it is done, thanks to the call to tasklet_wakeup_after() which replaces from now on
the call to tasklet_wakeup(). This should reduce drastically the latency and the
chances to fulfil the RX buffers at the QUIC connections level as reported in
GH #1737 by Tritan.
These modifications depend on this commit:
"MINOR: task: Add tasklet_wakeup_after()"
Must be backported to 2.6 with the previous commit.
Remove the call to qc_list_all_rx_pkts() which print messages on stderr
during RX buffer overruns and add a new counter for the number of dropped packets
because of such events.
Must be backported to 2.6
When the connection RX buffer is full, the received packets are dropped.
Some of them were not taken into an account by the ->dropped_pkt counter.
This very simple patch has no impact at all on the packet handling workflow.
Must be backported to 2.6.
In GH #1760 (which is marked as being a feature), there were compilation
errors on MacOS which could be reproduced in Linux when building 32-bit code
(-m32 gcc option). Most of them were due to variables types mixing in QUIC_MIN macro
or using size_t type in place of uint64_t type.
Must be backported to 2.6.
A curious practise seems to have started long ago and contaminated various
code areas, consisting in appending "_pool" at the end of the name of a
given pool. That makes no sense as the name is only used to name the pool
in diags such as "show pools", and since names are truncated there, this
adds some confusion when analysing the dump outputs. Let's just clean all
of them at once. there were essentially in SSL and QUIC.
This bug was revealed by key_update QUIC tracker test. During this test,
after the handshake has succeeded, the client sends a 1-RTT packet containing
only a PING frame. On our side, we do not acknowledge it, because we have
no ack-eliciting packet to send. This is not correct. We must acknowledge all
the ack-eliciting packets unconditionally. But we must not send too much
ACK frames: every two packets since we have sent an ACK frame. This is the test
(nb_aepkts_since_last_ack >= QUIC_MAX_RX_AEPKTS_SINCE_LAST_ACK) which ensure
this is the case. But this condition must be checked at the very last time,
when we are building a packet and when an acknowledgment is required. This
is not to qc_may_build_pkt() to do that. This boolean function decides if
we have packets to send. It must return "true" if there is no more ack-eliciting
packets to send and if an acknowledgement is required.
We must also add a "force_ack" parameter to qc_build_pkt() to force the
acknowledments during the handshakes (for each packet). If not, they will
be sent every two packets. This parameter must be passed to qc_do_build_pkt()
and be checked alongside the others conditions when building a packet to
decide to add an ACK frame or not to this packet.
Must be backported to 2.6.
Implement quic_tp_version_info_dump() to dump such a transport parameter (only remote).
Call it from quic_transport_params_dump() which dump all the transport parameters.
Can be backported to 2.6 as it's useful for debugging.
