This bug arrives with this commit:
982896961 MINOR: quic: split and rename qc_lstnr_pkt_rcv()
The first block of code consists in possibly setting this variable to true.
But it was already initialized to true before entering this code section.
Should be initialized to false.
Also take the opportunity to remove an unused "err" label.
Must be backported to 2.6 and 2.7.
Before probing the Initial packet number space, verify that we can at least
sent 1200 bytes by datagram. This may not be the case due to the amplification limit.
Must be backported to 2.6 and 2.7.
This should help in diagnosing issues revealed by the interop runner which counts
the number of handshakes from the number of Initial packets sent by the server.
Must be backported to 2.7.
The aim of this function is to rearm the idle timer. The ->expire
field of the timer task was updated without being requeued.
Some connection could be unexpectedly terminated.
Must be backported to 2.6 and 2.7.
This is very helpful during retranmission when receiving ICMP port unreachable
errors after the peer has left. This is the unique case at prevent where
qc_send_hdshk_pkts() or qc_send_app_probing() may fail (when they call
qc_send_ppkts() which fails with ECONNREFUSED as errno).
Also make the callers qc_dgrams_retransmit() stop their packet process. This
is the case of quic_conn_app_io_cb() and quic_conn_io_cb().
This modifications stops definitively any packet processing when receiving
ICMP port unreachable errors.
Must be backported to 2.7.
The send*() syscall which are responsible of such ICMP packets reception
fails with ECONNREFUSED as errno.
man(7) udp
ECONNREFUSED
No receiver was associated with the destination address.
This might be caused by a previous packet sent over the socket.
We must kill asap the underlying connection.
Must be backported to 2.7.
This code was there because the timer task was not running on the same thread
as the one which parse the QUIC packets. Now that this is no more the case,
we can wake up this task directly.
Must be backported to 2.7.
Move quic_rx_pkts_del() out of quic_conn.h to make it benefit from the TRACE API.
Add traces which already already helped in diagnosing an issue encountered with
ngtcp2 which sent too much 1RTT packets before the handshake completion. This
has been fixed here after having discussed with Tasuhiro on QUIC dev slack:
https://github.com/ngtcp2/ngtcp2/pull/663
Must be backported to 2.7.
There was a parenthesis placed in the wrong place for a memcmp().
As a consequence, clients could not reuse a UDP address for a new connection.
Must be backported to 2.7.
This has been detected by libasan as follows:
=================================================================
==3170559==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55cf77faad08 at pc 0x55cf77a87370 bp 0x7ffc01bdba70 sp 0x7ffc01bdba68
READ of size 8 at 0x55cf77faad08 thread T0
#0 0x55cf77a8736f in cli_find_kw src/cli.c:335
#1 0x55cf77a8a9bb in cli_parse_request src/cli.c:792
#2 0x55cf77a8c385 in cli_io_handler src/cli.c:1024
#3 0x55cf77d19ca1 in task_run_applet src/applet.c:245
#4 0x55cf77c0b6ba in run_tasks_from_lists src/task.c:634
#5 0x55cf77c0cf16 in process_runnable_tasks src/task.c:861
#6 0x55cf77b48425 in run_poll_loop src/haproxy.c:2934
#7 0x55cf77b491cf in run_thread_poll_loop src/haproxy.c:3127
#8 0x55cf77b4bef2 in main src/haproxy.c:3783
#9 0x7fb8b0693d09 in __libc_start_main ../csu/libc-start.c:308
#10 0x55cf7764f4c9 in _start (/home/flecaille/src/haproxy-untouched/haproxy+0x1914c9)
0x55cf77faad08 is located 0 bytes to the right of global variable 'cli_kws' defined in 'src/quic_conn.c:7834:27' (0x55cf77faaca0) of size 104
SUMMARY: AddressSanitizer: global-buffer-overflow src/cli.c:335 in cli_find_kw
Shadow bytes around the buggy address:
According to cli_find_kw() code and cli_kw_list struct definition, the second
member of this structure ->kw[] must be a null-terminated array.
Add a last element with default initializers to <cli_kws> global variable which
is impacted by this bug.
This bug arrived with this commit:
15c74702d MINOR: quic: implement a basic "show quic" CLI handler
Must be backported to 2.7 where this previous commit has been already
backported.
Incorrect printf format specifier "%lu" was used on "show quic" handler
for uint64_t. This breaks build on 32-bits architecture. To fix this
portability issue, force an explicit cast to unsigned long long with
"%llu" specifier.
This must be backported up to 2.7.
Filtering of closing/draining connections on "show quic" was not
properly implemented. This causes the extra argument "all" to display
all connections to be without effect. This patch fixes this and restores
the output of all connections.
This must be backported up to 2.7.
Reduce default "show quic" output by masking connection on
closing/draing state due to a CONNECTION_CLOSE emission/reception. These
connections can still be displayed using the special argument "all".
This should be backported up to 2.7.
Complete "show quic" handler by displaying information about
quic_stream_desc entries. These structures are used to emit stream data
and store them until acknowledgment is received.
This should be backported up to 2.7.
Complete "show quic" handler by displaying various information related
to each encryption level and packet number space. Most notably, ack
ranges and bytes in flight are present to help debug retransmission
issues.
This should be backported up to 2.7.
Complete "show quic" handler by displaying information related to the
quic_conn owned socket. First, the FD is printed, followed by the
address of the local and remote endpoint.
This should be backported up to 2.7.
Complete "show quic" handler. Source and destination CIDs are printed
for every connection. This is complete by a state info to reflect if
handshake is completed and if a CONNECTION_CLOSE has been emitted or
received and the allocation status of the attached MUX. Finally the idle
timer expiration is also printed.
This should be backported up to 2.7.
Implement a basic "show quic" CLI handler. This command will be useful
to display various information on all the active QUIC frontend
connections.
This work is heavily inspired by "show sess". Most notably, a global
list of quic_conn has been introduced to be able to loop over them. This
list is stored per thread in ha_thread_ctx.
Also add three CLI handlers for "show quic" in order to allocate and
free the command context. The dump handler runs on thread isolation.
Each quic_conn is referenced using a back-ref to handle deletion during
handler yielding.
For the moment, only a list of raw quic_conn pointers is displayed. The
handler will be completed over time with more information as needed.
This should be backported up to 2.7.
When building STREAM frames in a packet buffer, if a frame is too large
it will be splitted in two. A shorten version will be used and the
original frame will be modified to represent the remaining space.
To ensure there is enough space to store the frame data length encoded
as a QUIC integer, we use the function max_available_room(). This
function can return 0 if there not only a small space left which is
insufficient for the frame header and the shorten data. Prior to this
patch, this wasn't check and an empty unneeded STREAM frame was built
and sent for nothing.
Change this by checking the value return by max_available_room(). If 0,
do not try to split this frame and continue to the next ones in the
packet.
On 2.6, this patch serves as an optimization which will prevent the building
of unneeded empty STREAM frames.
On 2.7, this behavior has the side-effect of triggering a BUG_ON()
statement on quic_build_stream_frame(). This BUG_ON() ensures that we do
not use quic_frame with OFF bit set if its offset is 0. This can happens
if the condition defined above is reproduced for a STREAM frame at
offset 0. An empty unneeded frame is built as descibed. The problem is
that the original frame is modified with its OFF bit set even if the
offset is still 0.
This must be backported up to 2.6.
The SCID (source connection ID) used by a peer (client or server) is sent into the
long header of a QUIC packet in clear. But it is also sent into the transport
parameters (initial_source_connection_id). As these latter are encrypted into the
packet, one must check that these two pieces of information do not differ
due to a packet header corruption. Furthermore as such a connection is unusuable
it must be killed and must stop as soon as possible processing RX/TX packets.
Implement qc_kill_con() to flag a connection as unusable and to kille it asap
waking up the idle timer task to release the connection.
Add a check to quic_transport_params_store() to detect that the SCIDs do not
match and make it call qc_kill_con().
Add several tests about connection to be killed at several critial locations,
especially in the TLS stack callback to receive CRYPTO data from or derive secrets,
and before preparing packet after having received others.
Must be backported to 2.6 and 2.7.
This is a bad idea to make the TLS ClientHello callback call qc_conn_finalize().
If this latter fails, this would generate a TLS alert and make the connection
send packet whereas it is not functional. But qc_conn_finalize() job was to
install the transport parameters sent by the QUIC listener. This installation
cannot be done at any time. This must be done after having possibly negotiated
the QUIC version and before sending the first Handshake packets. It seems
the better moment to do that in when the Handshake TX secrets are derived. This
has been found inspecting the ngtcp2 code. Calling SSL_set_quic_transport_params()
too late would make the ServerHello to be sent without the transport parameters.
The code for the connection update which was done from qc_conn_finalize() has
been moved to quic_transport_params_store(). So, this update is done as soon as
possible.
Add QUIC_FL_CONN_TX_TP_RECEIVED to flag the connection as having received the
peer transport parameters. Indeed this is required when the ClientHello message
is splitted between packets.
Add QUIC_FL_CONN_FINALIZED to protect the connection from calling qc_conn_finalize()
more than one time. This latter is called only when the connection has received
the transport parameters and after returning from SSL_do_hanshake() which is the
function which trigger the TLS ClientHello callback call.
Remove the calls to qc_conn_finalize() from from the TLS ClientHello callbacks.
Must be backported to 2.6. and 2.7.
This bug was revealed by some C1 interop tests (heavy hanshake packet
corruption) when receiving 1-RTT packets with a key phase update.
This lead the packet to be decrypted with the next key phase secrets.
But this latter is initialized only after the handshake is complete.
In fact, 1-RTT must never be processed before the handshake is complete.
Relying on the "qc->mux_state == QC_MUX_NULL" condition to check the
handshake is complete is wrong during 0-RTT sessions when the mux
is initialized before the handshake is complete.
Must be backported to 2.7 and 2.6.
This is not really a bug fix but an improvement. When the Handshake packet number
space has been detected as needed to be probed, we should also try to probe the
Initial packet number space if there are still packets in flight. Furthermore
we should also try to send up to two datagrams.
Must be backported to 2.6 and 2.7.
This function is called only when probing only one packet number space
(Handshake) or two times the same one (Application). So, there is no risk
to prepare two times the same frame when uneeded because we wanted to
probe two packet number spaces. The condition "ignore the packets which
has been coalesced to another one" is not necessary. More importantly
the bug is when we want to prepare a Application packet which has
been coalesced to an Handshake packet. This is always the case when
the first Application packet is sent. It is always coalesced to
an Handshake packet with an ACK frame. So, when lost, this first
application packet was never resent. It contains the HANDSHAKE_DONE
frame to confirm the completion of the handshake to the client.
Must be backported to 2.6 and 2.7.
During the handshake and when the handshake has not been confirmed
the acknowledgement delays reported by the peer may be larger
than max_ack_delay. max_ack_delay SHOULD be ignored before the
handshake is completed when computing the PTO. But the current code considered
the wrong condition "before the hanshake is completed".
Replace the enum value QUIC_HS_ST_COMPLETED by QUIC_HS_ST_CONFIRMED to
fix this issue. In quic_loss.c, the parameter passed to quic_pto_pktns()
is renamed to avoid any possible confusion.
Must be backported to 2.7 and 2.6.
This may happen during retransmission of frames which can be splitted
(CRYPTO, or STREAM frames). One may have to split a frame to be
retransmitted due to the QUIC protocol properties (packet size limitation
and packet field encoding sizes). The remaining part of a frame which
cannot be retransmitted must be detached from the original frame it is
copied from. If not, when the really sent part will be acknowledged
the remaining part will be acknowledged too but not sent!
Must be backported to 2.7 and 2.6.
Define a new configuration option "tune.quic.max-frame-loss". This is
used to specify the limit for which a single frame instance can be
detected as lost. If exceeded, the connection is closed.
This should be backported up to 2.7.
Add a <loss_count> new field in quic_frame structure. This field is set
to 0 and incremented each time a sent packet is declared lost. If
<loss_count> reached a hard-coded limit, the connection is deemed as
failing and is closed immediately with a CONNECTION_CLOSE using
INTERNAL_ERROR.
By default, limit is set to 10. This should ensure that overall memory
usage is limited if a peer behaves incorrectly.
This should be backported up to 2.7.
Define a new function qc_frm_free() to handle frame deallocation. New
BUG_ON() statements ensure that the deallocated frame is not referenced
by other frame. To support this, all LIST_DELETE() have been replaced by
LIST_DEL_INIT(). This should enforce that frame deallocation is robust.
As a complement, qc_frm_unref() has been moved into quic_frame module.
It is justified as this is a utility function related to frame
deallocation. It allows to use it in quic_pktns_tx_pkts_release() before
calling qc_frm_free().
This should be backported up to 2.7.
Define two utility functions for quic_frame allocation :
* qc_frm_alloc() is used to allocate a new frame
* qc_frm_dup() is used to allocate a new frame by duplicating an
existing one
Theses functions are useful to centralize quic_frame initialization.
Note that pool_zalloc() is replaced by a proper pool_alloc() + explicit
initialization code.
This commit will simplify implementation of the per frame retransmission
limitation. Indeed, a new counter will be added in quic_frame structure
which must be initialized to 0.
This should be backported up to 2.7.
Care must be taken when reading/writing offset for STREAM frames. A
special OFF bit is set in the frame type to indicate that the field is
present. If not set, it is assumed that offset is 0.
To represent this, offset field of quic_stream structure must always be
initialized with a valid value in regards with its frame type OFF bit.
The previous code has no bug in part because pool_zalloc() is used to
allocate quic_frame instances. To be able to use pool_alloc(), offset is
always explicitely set to 0. If a non-null value is used, OFF bit is set
at the same occasion. A new BUG_ON() statement is added on frame builder
to ensure that the caller has set OFF bit if offset is non null.
This should be backported up to 2.7.
A dedicated <fin> field was used in quic_stream structure. However, this
info is already encoded in the frame type field as specified by QUIC
protocol.
In fact, only code for packet reception used the <fin> field. On the
sending side, we only checked for the FIN bit. To align both sides,
remove the <fin> field and only used the FIN bit.
This should be backported up to 2.7.
It is forbidden to request h3 clients to close its Control and QPACK unidirection
streams. If not, the client closes the connection with H3_CLOSED_CRITICAL_STREAM(0x104).
Perhaps this could prevent some clients as Chrome to come back for a while.
But at quic_conn level there is no mean to identify the streams for which we cannot
send STOP_SENDING frame. Such a possibility is even not mentionned in RFC 9000.
At this time there is no choice than stopping sending STOP_SENDING frames for
all the h3 unidirectional streams inspecting the ->app_opps quic_conn value.
Must be backported to 2.7 and 2.6.
Set "disable_active_migration" transport parameter to inform the peer
haproxy listeners does not the connection migration feature.
Also drop all received datagrams with a modified source address.
Must be backported to 2.7.
Implement RESET_STREAM reception by mux-quic. On reception, qcs instance
will be mark as remotely closed and its Rx buffer released. The stream
layer will be flagged on error if still attached.
This commit is part of implementing H3 errors at the stream level.
Indeed, on H3 stream errors, STOP_SENDING + RESET_STREAM should be
emitted. The STOP_SENDING will in turn generate a RESET_STREAM by the
remote peer which will be handled thanks to this patch.
This should be backported up to 2.7.
Shards were completely forgotten in commit f5a0c8abf ("MEDIUM: quic:
respect the threads assigned to a bind line"). The thread mask is
taken from the bind_conf, but since shards were introduced in 2.5,
the per-listener mask is held by the receiver and can be smaller
than the bind_conf's mask.
The effect here is that the traffic is not distributed to the
appropriate thread. At first glance it's not dramatic since it remains
one of the threads eligible by the bind_conf, but it still means that
in some contexts such as "shards by-thread", some concurrency may
persist on listeners while they're expected to be alone. One identified
impact is that it requires more rxbufs than necessary, but there may
possibly be other not yet identified side effects.
This must be backported to 2.7 and everywhere the commit above is
backported.
There is a possible segfault when accessing qc->timer_task in
quic_conn_io_cb() without testing it. It seems however very rare as it
requires several condition to be encounter.
* quic_conn must be in CLOSING state after having sent a
CONNECTION_CLOSE which free the qc.timer_task
* quic_conn handshake must still be in progress : in fact, qc.timer_task
is accessed on this path because of the anti-amplification limit
lifted.
I was unable thus far to trigger it but benchmarking tests seems to have
fire it with the following backtrace as a result :
#0 _task_wakeup (f=4096, caller=0x5620ed004a40 <_.46868>, t=0x0) at include/haproxy/task.h:195
195 state = _HA_ATOMIC_OR_FETCH(&t->state, f);
[Current thread is 1 (Thread 0x7fc714ff1700 (LWP 14305))]
(gdb) bt
#0 _task_wakeup (f=4096, caller=0x5620ed004a40 <_.46868>, t=0x0) at include/haproxy/task.h:195
#1 quic_conn_io_cb (t=0x7fc5d0e07060, context=0x7fc5d0df49c0, state=<optimized out>) at src/quic_conn.c:4393
#2 0x00005620ecedab6e in run_tasks_from_lists (budgets=<optimized out>) at src/task.c:596
#3 0x00005620ecedb63c in process_runnable_tasks () at src/task.c:861
#4 0x00005620ecea971a in run_poll_loop () at src/haproxy.c:2913
#5 0x00005620ecea9cf9 in run_thread_poll_loop (data=<optimized out>) at src/haproxy.c:3102
#6 0x00007fc773c3f609 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#7 0x00007fc77372d133 in clone () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) up
#1 quic_conn_io_cb (t=0x7fc5d0e07060, context=0x7fc5d0df49c0, state=<optimized out>) at src/quic_conn.c:4393
4393 task_wakeup(qc->timer_task, TASK_WOKEN_MSG);
(gdb) p qc
$1 = (struct quic_conn *) 0x7fc5d0df49c0
(gdb) p qc->timer_task
$2 = (struct task *) 0x0
This fix should be backported up to 2.6.
This patch is the follow up of previous fix :
BUG/MINOR: quic: properly handle alloc failure in qc_new_conn()
quic_conn owned socket FD is initialized as soon as possible in
qc_new_conn(). This guarantees that we can safely call
quic_conn_release() on allocation failure. This function uses internally
qc_release_fd() to free the socket FD unless it has been initialized to
an invalid FD value.
Without this patch, a segfault will occur if one inner allocation of
qc_new_conn() fails before qc.fd is initialized.
This change is linked to quic-conn owned socket implementation.
This should be backported up to 2.7.
qc_new_conn() is used to allocate a quic_conn instance and its various
internal members. If one allocation fails, quic_conn_release() is used
to cleanup things.
For the moment, pool_zalloc() is used which ensures that all content is
null. However, some members must be initialized to a special values
to be able to use quic_conn_release() safely. This is the case for
quic_conn lists and its tasklet.
Also, some quic_conn internal allocation functions were doing their own
cleanup on failure without reset to NULL. This caused an issue with
quic_conn_release() which also frees this members. To fix this, these
functions now only return an error without cleanup. It is the caller
responsibility to free the allocated content, which is done via
quic_conn_release().
Without this patch, allocation failure in qc_new_conn() would often
result in segfault. This was reproduced easily using fail-alloc at 10%.
This should be backported up to 2.6.
UDP addresses may change over time for a QUIC connection. When using
quic-conn owned socket, we have to detect address change to break the
bind/connect association on the socket.
For the moment, on change detected, QUIC connection socket is closed and
a new one is opened. In the future, we may improve this by trying to
keep the original socket and reexecute only bind/connect syscalls.
This change is part of quic-conn owned socket implementation.
It may be backported to 2.7 after a period of observation.
This change is the second part for reception on QUIC connection socket.
All operations inside the FD handler has been delayed to quic-conn
tasklet via the new function qc_rcv_buf().
With this change, buffer management on reception has been simplified. It
is now possible to use a local buffer inside qc_rcv_buf() instead of
quic_receiver_buf().
This change is part of quic-conn owned socket implementation.
It may be backported to 2.7 after a period of observation.
Try to use the quic-conn socket for reception if it is allocated. For
this, the socket is inserted in the fdtab. This will call the new
handler quic_conn_io_cb() which is responsible to process the recv()
system call. It will reuse datagram dispatch for simplicity. However,
this is guaranteed to be called on the quic-conn thread, so it will be
more efficient to use a dedicated buffer. This will be implemented in
another commit.
This patch should improve performance by reducing contention on the
receiver socket. However, more gain can be obtained when the datagram
dispatch operation will be skipped.
Older quic_sock_fd_iocb() is renamed to quic_lstnr_sock_fd_iocb() to
emphasize its usage for the receiver socket.
This change is part of quic-conn owned socket implementation.
It may be backported to 2.7 after a period of observation.
Allocate quic-conn owned socket if possible. This requires that this is
activated in haproxy configuration. Also, this is done only if local
address is known so it depends on the support of IP_PKTINFO.
For the moment this socket is not used. This causes QUIC support to be
broken as received datagram are not read. This commit will be completed
by a following patch to support recv operation on the newly allocated
socket.
This change is part of quic-conn owned socket implementation.
It may be backported to 2.7 after a period of observation.
QUIC protocol support address migration which allows to maintain the
connection even if client has changed its network address. This is done
through address migration.
RFC 9000 stipulates that address migration is forbidden before handshake
has been completed. Add a check for this : drop silently every datagram
if client network address has changed until handshake completion.
This commit is one of the first steps towards QUIC connection migration
support.
This should be backported up to 2.7.
Detect connection migration attempted by the client. This is done by
comparing addresses stored in quic-conn with src/dest addresses of the
UDP datagram.
A new function qc_handle_conn_migration() has been added. For the
moment, no operation is conducted and the function will be completed
during connection migration implementation. The only notable things is
the increment of a new counter "quic_conn_migration_done".
This should be backported up to 2.7.
Extract individual datagram parsing code outside of datagrams list loop
in quic_lstnr_dghdlr(). This is moved in a new function named
quic_dgram_parse().
To complete this change, quic_lstnr_dghdlr() has been moved into
quic_sock source file : it belongs to QUIC socket lower layer and is
directly called by quic_sock_fd_iocb().
This commit will ease implementation of quic-conn owned socket.
New function quic_dgram_parse() will be easily usable after a receive
operation done on quic-conn IO-cb.
This should be backported up to 2.7.
quic_rx_packet struct had a reference to the quic_conn instance. This is
useless as qc instance is always passed through function argument. In
fact, pkt.qc is used only in qc_pkt_decrypt() on key update, even though
qc is also passed as argument.
Simplify this by removing qc field from quic_rx_packet structure
definition. Also clean up qc_pkt_decrypt() documentation and interface
to align it with other quic-conn related functions.
This should be backported up to 2.7.
qc_dgrams_retransmit() could reuse the same local list and could splice it two
times to the packet number space list of frame to be send/resend. This creates a
loop in this list and makes qc_build_frms() possibly endlessly loop when trying
to build frames from the packet number space list of frames. Then haproxy aborts.
This issue could be easily reproduced patching qc_build_frms() function to set <dlen>
variable value to 0 after having built at least 10 CRYPTO frames and using ngtcp2
as client with 30% packet loss in both direction.
Thank you to @gabrieltz for having reported this issue in GH #1903.
Must be backported to 2.6.
Gcc 6.5 is now well known for triggering plenty of false "may be used
uninitialized", particularly at -O1, and two of them happen in quic,
quic_tp and quic_conn. Both of them were reviewed and easily confirmed
as wrong (gcc seems to ignore the control flow after the function
returns and believes error conditions are not met). Let's just preset
the variables that bothers it. In quic_tp the initialization was moved
out of the loop since there's no point inflating the code just to
silence a stupid warning.
This previous patch was not sufficient to prevent haproxy from
crashing when some Handshake packets had to be inspected before being possibly
retransmitted:
"BUG/MAJOR: quic: Crash upon retransmission of dgrams with several packets"
This patch introduced another issue: access to packets which have been
released because still attached to others (in the same datagram). This was
the case for instance when discarding the Initial packet number space before
inspecting an Handshake packet in the same datagram through its ->prev or
member in our case.
This patch implements quic_tx_packet_dgram_detach() which detaches a packet
from the adjacent ones in the same datagram to be called when ackwowledging
a packet (as done in the previous commit) and when releasing its memory. This
was, we are sure the released packets will not be accessed during retransmissions.
Thank you to @gabrieltz for having reported this issue in GH #1903.
Must be backported to 2.6.
As revealed by some traces provided by @gabrieltz in GH #1903 issue,
there are clients (chrome I guess) which acknowledge only one packet among others
in the same datagram. This is the case for the first datagram sent by a QUIC haproxy
listener made an Initial packet followed by an Handshake one. In this identified
case, this is the Handshake packet only which is acknowledged. But if the
client is able to respond with an Handshake packet (ACK frame) this is because
it has successfully parsed the Initial packet. So, why not also acknowledging it?
AFAIK, this is mandatory. On our side, when restransmitting this datagram, the
Handshake packet was accessed from the Initial packet after having being released.
Anyway. There is an issue on our side. Obviously, we must not expect an
implementation to respect the RFC especially when it want to build an attack ;)
With this simple patch for each TX packet we send, we also set the previous one
in addition to the next one. When a packet is acknowledged, we detach the next one
and the next one in the same datagram from this packet, so that it cannot be
resent when resending these packets (the previous one, in our case).
Thank you to @gabrieltz for having reported this issue.
Must be backported to 2.6.
Add more traces to follow CRYPTO data buffering in ncbuf. Offset for
quic_enc_level is now reported for event QUIC_EV_CONN_PRHPKTS. Also
ncb_advance() must never fail so a BUG_ON() statement is here to
guarantee it.
This was useful to track handshake failure reported too often. This is
related to github issue #1903.
This should be backported up to 2.6.
Liberate quic_enc_level ncbuf in quic_stream_free(). In most cases, this
will already be done when handshake is completed via
qc_treat_rx_crypto_frms(). However, if a connection is released before
handshake completion, a leak was present without this patch.
Under normal situation, this leak should have been limited due to the
majority of QUIC connection success on handshake. However, another bug
caused handshakes to fail too frequently, especially with chrome client.
This had the side-effect to dramatically increase this memory leak.
This should fix in part github issue #1903.
QUIC handshakes were frequently in error due to haproxy misuse of
ncbuf. This resulted in one of the following scenario :
- handshake rejected with CONNECTION_CLOSE due to overlapping data
rejected
- CRYPTO data fully received by haproxy but handshake completion signal
not reported causing the client to emit PING repeatedly before timeout
This was produced because ncb_advance() result was not checked after
providing crypto data to the SSL stack in qc_provide_cdata(). However,
this operation can fail if a too small gap is formed. In the meantime,
quic_enc_level offset was always incremented. In some cases, this caused
next ncb_add() to report rejected overlapping data. In other cases, no
error was reported but SSL stack never received the end of CRYPTO data.
Change slightly the handling of new CRYPTO frames to avoid this bug :
when receiving a CRYPTO frame for the current offset, handle them
directly as previously done only if quic_enc_level ncbuf is empty. In
the other case, copy them to the buffer before treating contiguous data
via qc_treat_rx_crypto_frms().
This change ensures that ncb_advance() operation is now conducted only
in a data block : thus this is guaranteed to never fail.
This bug was easily reproduced with chromium as it fragments CRYPTO
frames randomly in several frames out of order.
This commit has two drawbacks :
- it is slightly less worst on performance because as sometimes even
data at the current offset will be memcpy
- if a client uses too many fragmented CRYPTO frames, this can cause
repeated ncb_add() error on gap size. This can be reproduced with
chrome, albeit with a slighly less frequent rate than the fixed issue.
This change should fix in part github issue #1903.
This must be backported up to 2.6.
With GCC 12.2.0 and O2 optimization activated, compiler reports the
following warning for qc_release_lost_pkts().
In function ‘quic_tx_packet_refdec’,
inlined from ‘qc_release_lost_pkts.constprop’ at src/quic_conn.c:2056:3:
include/haproxy/atomic.h:320:41: error: ‘__atomic_sub_fetch_4’ writing 4 bytes into a region of size 0 overflows the destination [-Werror=stringop-overflow=]
320 | #define HA_ATOMIC_SUB_FETCH(val, i) __atomic_sub_fetch(val, i, __ATOMIC_SEQ_CST)
| ^~~~~~~~~~~~~~~~~~
include/haproxy/quic_conn.h:499:14: note: in expansion of macro ‘HA_ATOMIC_SUB_FETCH’
499 | if (!HA_ATOMIC_SUB_FETCH(&pkt->refcnt, 1)) {
| ^~~~~~~~~~~~~~~~~~~
GCC thinks that quic_tx_packet_refdec() can be called with a NULL
argument from qc_release_lost_pkts() with <oldest_lost> as arg.
This warning is a false positive as <oldest_lost> cannot be NULL in
qc_release_lost_pkts() at this stage. This is due to the previous check
to ensure that <pkts> list is not empty.
This warning is silenced by using ALREADY_CHECKED() macro.
This should be backported up to 2.6.
This should fix github issue #1852.
Subscribing was not properly designed between quic-conn and quic MUX
layers. Align this as with in other haproxy components : <subs> field is
moved from the MUX to the quic-conn structure. All mention of qcc MUX is
cleaned up in quic_conn_subscribe()/quic_conn_unsubscribe().
Thanks to this change, ACK reception notification has been simplified.
It's now unnecessary to check for the MUX existence before waking it.
Instead, if <subs> quic-conn field is set, just wake-up the upper layer
tasklet without mentionning MUX. This should probably be extended to
other part in quic-conn code.
This should be backported up to 2.6.
On Initial packet reception, token is checked for validity through
quic_retry_token_check() function. However, some related parts were left
in the parent function quic_rx_pkt_retrieve_conn(). Move this code
directly into quic_retry_token_check() to facilitate its call in various
context.
The API of quic_retry_token_check() has also been refactored. Instead of
working on a plain char* buffer, it now uses a quic_rx_packet instance.
This helps to reduce the number of parameters.
This change will allow to check Retry token even if data were received
with a FD-owned quic-conn socket. Indeed, in this case,
quic_rx_pkt_retrieve_conn() call will probably be skipped.
This should be backported up to 2.6.
Sometimes, a packet is dropped on reception. Several goto statements are
used, mostly to increment a proxy drop counter or drop silently the
packet. However, this labels are interleaved. Re-arrang goto labels to
simplify this process :
* drop label is used to drop a packet with counter incrementation. This
is the default method.
* drop_silent is the next label which does the same thing but skip the
counter incrementation. This is useful when we do not need to report
the packet dropping operation.
This should be backported up to 2.6.
This change is the following of qc_lstnr_pkt_rcv() refactoring. This
function has finally been split into several ones.
The first half is renamed quic_rx_pkt_parse(). This function is
responsible to parse a QUIC packet header and calculate the packet
length.
QUIC connection retrieval has been extracted and is now called directly
by quic_lstnr_dghdlr().
The second half of qc_lstnr_pkt_rcv() is renamed to qc_rx_pkt_handle().
This function is responsible to copy a QUIC packet content to a
quic-conn receive buffer.
A third function named qc_rx_check_closing() is responsible to detect if
the connection is already in closing state. As this requires to drop the
whole datagram, it seems justified to be in a separate function.
This change has no functional impact. It is part of a refactoring series
on qc_lstnr_pkt_rcv(). The objective is to facilitate the integration of
FD-owned quic-conn socket patches.
This should be backported up to 2.6.
Simplify qc_lstnr_pkt_rcv() by extracting code responsible to retrieve
the quic-conn instance. This code is put in a dedicated function named
quic_rx_pkt_retrieve_conn(). This new function could be skipped if a
FD-owned quic-conn socket is used.
The first traces of qc_lstnr_pkt_rcv() have been clean up as qc instance
is always NULL here : thus qc parameter can be removed without any
change.
This change has no functional impact. It is a part of a refactoring
series on qc_lstnr_pkt_rcv(). The objective is facilitate integration of
FD-owned socket patches.
This should be backported up to 2.6.
Received packets treatment has some difference regarding if this is the
first one or not of the encapsulating datagram. Previously, this was set
via a function argument. Simplify this by defining a new Rx packet flag
named QUIC_FL_RX_PACKET_DGRAM_FIRST.
This change does not have functional impact. It will simplify API when
qc_lstnr_pkt_rcv() is broken into several functions : their number of
arguments will be reduced thanks to this patch.
This should be backported up to 2.6.
pn_offset field was only set if header protection cannot be removed.
Extend the usage of this field : it is now set everytime on packet
parsing in qc_lstnr_pkt_rcv().
This change helps to clean up API of Rx functions by removing
unnecessary variables and function argument.
This change has no functional impact. It is a part of a refactoring
series on qc_lstnr_pkt_rcv(). The objective is facilitate integration of
FD-owned socket patches.
This should be backported up to 2.6.
Add a new field version on quic_rx_packet structure. This is set on
header parsing in qc_lstnr_pkt_rcv() function.
This change has no functional impact. It is a part of a refactoring
series on qc_lstnr_pkt_rcv(). The objective is facilitate integration of
FD-owned socket patches.
This should be backported up to 2.6.
When generating a Retry token, client CID is used as encryption input.
The client must reuse the same CID when emitting the token in a new
Initial packet.
A memory overflow can occur on quic_generate_retry_token() depending on
the size of client CID. This is because space reserved for <aad> only
accounted for QUIC_HAP_CID_LEN (size of haproxy owned generated CID).
However, the client CID size only depends on client parameter and is
instead limited to QUIC_CID_MAXLEN as specified in RFC9000.
This was reproduced with ngtcp2 and haproxy built with ASAN. Here is the error
log :
==14964==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffee228cee at pc 0x7ffff785f427 bp 0x7fffee2289e0 sp 0x7fffee228188
WRITE of size 17 at 0x7fffee228cee thread T5
#0 0x7ffff785f426 in __interceptor_memcpy /usr/src/debug/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
#1 0x555555906ea7 in quic_generate_retry_token_aad src/quic_conn.c:5452
#2 0x555555907e72 in quic_retry_token_check src/quic_conn.c:5577
#3 0x55555590d01e in qc_lstnr_pkt_rcv src/quic_conn.c:6103
#4 0x5555559190fa in quic_lstnr_dghdlr src/quic_conn.c:7179
#5 0x555555eb0abf in run_tasks_from_lists src/task.c:590
#6 0x555555eb285f in process_runnable_tasks src/task.c:855
#7 0x555555d9118f in run_poll_loop src/haproxy.c:2853
#8 0x555555d91f88 in run_thread_poll_loop src/haproxy.c:3042
#9 0x7ffff709f8fc (/usr/lib/libc.so.6+0x868fc)
#10 0x7ffff7121a5f (/usr/lib/libc.so.6+0x108a5f)
This must be backported up to 2.6.
Right now the QUIC thread mapping derives the thread ID from the CID
by dividing by global.nbthread. This is a problem because this makes
QUIC work on all threads and ignores the "thread" directive on the
bind lines. In addition, only 8 bits are used, which is no more
compatible with the up to 4096 threads we may have in a configuration.
Let's modify it this way:
- the CID now dedicates 12 bits to the thread ID
- on output we continue to place the TID directly there.
- on input, the value is extracted. If it corresponds to a valid
thread number of the bind_conf, it's used as-is.
- otherwise it's used as a rank within the current bind_conf's
thread mask so that in the end we still get a valid thread ID
for this bind_conf.
The extraction function now requires a bind_conf in order to get the
group and thread mask. It was better to use bind_confs now as the goal
is to make them support multiple listeners sooner or later.
QUIC datagrams are read from a random thread. They are then redispatch
to the connection thread according to the first packet DCID. These
operations are implemented through a special buffer designed to avoid
locking.
Refactor this code with the following changes :
* <rxbuf> type is renamed <quic_receiver_buf>. Its list element is also
renamed to highligh its attach point to a receiver.
* <quic_dgram> and <quic_receiver_buf> definition are moved to
quic_sock-t.h. This helps to reduce the size of quic_conn-t.h.
* <quic_dgram> list elements are renamed to highlight their attach point
into a <quic_receiver_buf> and a <quic_dghdlr>.
This should be backported up to 2.6.
Implement quic_tls_secrets_keys_alloc()/quic_tls_secrets_keys_free() to allocate
the memory for only one direction (RX or TX).
Modify ha_quic_set_encryption_secrets() to call these functions for one of this
direction (or both). So, for now on we can rely on the value of the secret keys
to know if it was derived.
Remove QUIC_FL_TLS_SECRETS_SET flag which is no more useful.
Consequently, the secrets are dumped by the traces only if derived.
Must be backported to 2.6.
This issue was reproduced with -Q picoquic client option to split a big ClientHello
message into two Initial packets and haproxy as server without any knowledged of
any previous ORTT session (restarted after a firt 0RTT session). The ORTT received
packets were removed from their queue when the second Initial packet was parsed,
and the QUIC handshake state never progressed and remained at Initial state.
To avoid such situations, after having treated some Initial packets we always
check if there are ORTT packets to parse and we never remove them from their
queue. This will be done after the hanshake is completed or upon idle timeout
expiration.
Also add more traces to be able to analize the handshake progression.
Tested with ngtcp2 and picoquic
Must be backported to 2.6.
Implement quic_get_ncbuf() to dynamically allocate a new ncbuf to be attached to
any quic_cstream struct which needs such a buffer. Note that there is no quic_cstream
for 0RTT encryption level. quic_free_ncbuf() is added to release the memory
allocated for a non-contiguous buffer.
Modify qc_handle_crypto_frm() to call this function and allocate an ncbuf for
crypto data which are not received in order. The crypto data which are received in
order are not buffered but provide to the TLS stack (calling qc_provide_cdata()).
Modify qc_treat_rx_crypto_frms() which is called after having provided the
in order received crypto data to the TLS stack to provide again the remaining
crypto data which has been buffered, if possible (if they are in order). Each time
buffered CRYPTO data were consumed, we try to release the memory allocated for
the non-contiguous buffer (ncbuf).
Also move rx.crypto.offset quic_enc_level struct member to rx.offset quic_cstream
struct member.
Must be backported to 2.6.
Add new quic_cstream struct definition to implement the CRYPTO data stream.
This is a simplication of the qcs object (QUIC streams) for the CRYPTO data
without any information about the flow control. They are not attached to any
tree, but to a QUIC encryption level, one by encryption level except for
the early data encryption level (for 0RTT). A stream descriptor is also allocated
for each CRYPTO data stream.
Must be backported to 2.6
Retrieve the frontend destination address for a QUIC connection. This
address is retrieve from the first received datagram and then stored in
the associated quic-conn.
This feature relies on IP_PKTINFO or affiliated flags support on the
socket. This flag is set for each QUIC listeners in
sock_inet_bind_receiver(). To retrieve the destination address,
recvfrom() has been replaced by recvmsg() syscall. This operation and
parsing of msghdr structure has been extracted in a wrapper quic_recv().
This change is useful to finalize the implementation of 'dst' sample
fetch. As such, quic_sock_get_dst() has been edited to return local
address from the quic-conn. As a best effort, if local address is not
available due to kernel non-support of IP_PKTINFO, address of the
listener is returned instead.
This should be backported up to 2.6.
Continue on the cleanup of QUIC stack and components.
quic_conn uses internally a ssl_sock_ctx to handle mandatory TLS QUIC
integration. However, this is merely as a convenience, and it is not
equivalent to stackable ssl xprt layer in the context of HTTP1 or 2.
To better emphasize this, ssl_sock_ctx usage in quic_conn has been
removed wherever it is not necessary : namely in functions not related
to TLS. quic_conn struct now contains its own wait_event for tasklet
quic_conn_io_cb().
This should be backported up to 2.6.
xprt_quic module was too large and did not reflect the true architecture
by contrast to the other protocols in haproxy.
Extract code related to XPRT layer and keep it under xprt_quic module.
This code should only contains a simple API to communicate between QUIC
lower layer and connection/MUX.
The vast majority of the code has been moved into a new module named
quic_conn. This module is responsible to the implementation of QUIC
lower layer. Conceptually, it overlaps with TCP kernel implementation
when comparing QUIC and HTTP1/2 stacks of haproxy.
This should be backported up to 2.6.
