The new MEM_F_UAF flag can be set just after a pool's creation to make
this pool UAF for debugging purposes. This allows to maintain a better
overall performance required to reproduce issues while still having a
chance to catch UAF. It will only be used by developers who will manually
add it to areas worth being inspected, though.
Extend API used for QUIC transport parameter decoding. This is done via
the introduction of a dedicated enum to report the various error
condition detected. No functional change should occur with this patch,
as the only returned code is QUIC_TP_DEC_ERR_TRUNC, which results in the
connection closure via a TLS alert.
This patch will be necessary to properly reject transport parameters
with the proper CONNECTION_CLOSE error code. As such, it should be
backported up to 2.6 with the following series.
In order to make the lock history a bit more useful, let's try to merge
adjacent lock/unlock sequences that don't change anything for other
threads. For this we can replace the last unlock with the new operation
on the same label, and even just not store it if it was the same as the
one before the unlock, since in the end it's the same as if the unlock
had not been done.
Now loops that used to be filled with "R:LISTENER U:LISTENER" show more
useful info such as:
S:IDLE_CONNS U:IDLE_CONNS S:PEER U:PEER S:IDLE_CONNS U:IDLE_CONNS R:LISTENER U:LISTENER
U:STK_TABLE W:STK_SESS U:STK_SESS R:STK_TABLE U:STK_TABLE W:STK_SESS U:STK_SESS R:STK_TABLE
R:STK_TABLE U:STK_TABLE W:STK_SESS U:STK_SESS W:STK_TABLE_UPDT U:STK_TABLE_UPDT S:PEER
It's worth noting that it can sometimes induce confusion when recursive
locks of the same label are used (a few exist on peers or stick-tables),
as in such a case the two operations would be needed. However these ones
are already undebuggable, so instead they will just have to be renamed
to make sure they use a distinct label.
Most threads are filled with "R:OTHER U:OTHER" in their history. Since
anything non-important can use other it's not observable but it pollutes
the history. Let's just drop OTHER entirely during the recording.
There is a lot of contention trying to add updates to the tree. So
instead of trying to add the updates to the tree right away, just add
them to a mt-list (with one mt-list per thread group, so that the
mt-list does not become the new point of contention that much), and
create a tasklet dedicated to adding updates to the tree, in batchs, to
avoid keeping the update lock for too long.
This helps getting stick tables perform better under heavy load.
quic_conn_release() may, or may not, free the tasklet associated with
the connection. So make it return 1 if it was, and 0 otherwise, so that
if it was called from the tasklet handler itself, the said handler can
act accordingly and return NULL if the tasklet was destroyed.
This should be backported if 9240cd4a2771245fae4d0d69ef025104b14bfc23
is backported.
Add an extra parametre to conn_create_mux(), "closed_connection".
If a pointer is provided, then let it know if the connection was closed.
Callers have no way to determine that otherwise, and we need to know
that, at least in ssl_sock_io_cb(), as if the connection was closed we
need to return NULL, as the tasklet was free'd, otherwise that can lead
to memory corruption and crashes.
This should be backported if 9240cd4a2771245fae4d0d69ef025104b14bfc23
is backported too.
TASK_QUEUED was used to mean "the task has been scheduled to run",
TASK_IN_LIST was used to mean "the tasklet has been scheduled to run",
remove TASK_IN_LIST and just use TASK_QUEUED for tasklets instead.
This commit is just cosmetic, and should not have any impact.
Implement a way to display the running acme tasks over the CLI.
It currently only displays a "Running" status with the certificate name
and the acme section from the configuration.
The displayed running tasks are limited to the size of a buffer for now,
it will require a backref list later to be called multiple times to
resume the list.
When called, this function will try to enforce a yield (if available) as
soon as possible. Indeed, automatic yield is already enforced every X
Lua instructions. However, there may be some cases where we know after
running heavy operation that we should yield already to avoid taking too
much CPU at once.
This is what this function offers, instead of asking the user to manually
yield using "core.yield()" from Lua itself after using an expensive
Lua method offered by haproxy, we can directly enforce the yield without
the need to do it in the Lua script.
The previous commit has implemented a new calcul method for
MAX_STREAM_DATA frame emission. Now, a frame may be emitted as soon as a
buffer was consumed by a QCS instance.
This will probably increase the number of MAX_STREAM_DATA frame
emission. It may even cause a series of frame emitted for the same
stream with increasing values under high load, which is completely
unnecessary.
To improve this, limit the number of MAX_STREAM_DATA frames built to one
per QCS instance. This is implemented by storing a reference to this
frame in QCS structure via a new member <tx.msd_frm>.
Note that to properly reset QCS msd_frm member, emission of flow-control
frames have been changed. Now, each frame is emitted individually. On
one side, it is better as it prevent to emit frames related to different
streams in a single datagram, which is not desirable in case of packet
loss. However, this can also increase sendto() syscall invocation.
Recently, QCS Rx allocation buffer method has been improved. It is now
possible to allocate multiple buffers per QCS instances, which was
necessary to improve HTTP/3 POST throughput.
However, a limitation remained related to the emission of
MAX_STREAM_DATA. These frames are only emitted once at least half of the
receive capacity has been consumed by its QCS instance. This may be too
restrictive when a client need to upload a large payload.
Improve this by adjusting MAX_STREAM_DATA allocation. If QCS capacity is
still limited to 1 or 2 buffers max, the old calcul is still used. This
is necessary when user has limited upload throughput via their
configuration. If QCS capacity is more than 2 buffers, a new frame is
emitted if at least a buffer was consumed.
This patch has reduced number of STREAM_DATA_BLOCKED frames received in
POST tests with some specific clients.
We had to parse the sigAlg extension by hand in order to properly select
the certificate used by the SSL frontends. These traces allow to dump
the allowed sigAlg list sent by the client in its clientHello.
This callback allows to pick the used certificate on an SSL frontend.
The certificate selection is made according to the information sent by
the client in the clientHello. The traces that were added will allow to
better understand what certificate was chosen and why. It will also warn
us if the chosen certificate was the default one.
The actual certificate parsing happens in ssl_sock_chose_sni_ctx. It's
in this function that we actually get the filename of the certificate
used.
If OCSP stapling fails because of a missing or invalid OCSP response we
used to silently disable stapling for the given session. We can now know
a bit more what happened regarding OCSP stapling.
Those traces dump information about the multiple SSL_do_handshake calls
(renegotiation and regular call). Some errors coud also be dumped in
case of rejected early data.
Depending on the chosen verbosity, some information about the current
handshake can be dumped as well (servername, tls version, chosen cipher
for instance).
In case of failed handshake, the error codes and messages will also be
dumped in the log to ease debugging.
Add a dedicated trace for some unlikely allocation failures and async
errors. Those traces will ostly be used to identify the start and end of
a given SSL connection.
This function can be used to convert a TLSv1.3 sigAlg entry (2bytes)
from the signature_agorithms client hello extension into a string.
In order to ease debugging, some TLSv1.2 combinations can also be
dumped. In TLSv1.2 those signature algorithms pairs were built out of a
one byte signature identifier combined to a one byte hash identifier.
In TLSv1.3 those identifiers are two bytes blocs that must be treated as
such.
In relation to issue #2954, it appears that turning some size_t length
calculations to the int that uses my_strndup() upsets coverity a bit.
Instead of dealing with such warnings each time, better address it at
the root. An inspection of all call places show that the size passed
there is always positive so we can safely use an unsigned type, and
size_t will always suit it like for strndup() where it's available.
when dns session callback (dns_session_release()) is called upon error
(ie: when some pending queries were not sent), we try our best to
re-create the applet in order to preserve the pending queries and give
them a chance to be retried. This is done at the end of
dns_session_release().
However, doing so exposes to an issue: if the error preventing queries
from being sent is still encountered over and over the dns session could
stay there indefinitely. Meanwhile, other dns sessions may be created on
the same dns_stream_server periodically. If previous failing dns sessions
don't terminate but we also keep creating new ones, we end up accumulating
failing sessions on a given dns_stream_server, which can eventually cause
ressource shortage.
This issue was found when trying to address ("BUG/MINOR: dns: add tempo
between 2 connection attempts for dns servers")
To fix it, we track the number of failed consecutive sessions for a given
dns server. When we reach the threshold (set to 100), we consider that the
link to the dns server is broken (at least temporarily) and we force
dns_session_new() to fail, so that we stop creating new sessions until one
of the existing one eventually succeeds.
A workaround for this fix consists in setting the "maxconn" parameter on
nameserver directive (under resolvers section) to a reasonnable value so
that no more than "maxconn" sessions may co-exist on the same server at
a given time.
This may be backported to all stable versions.
("CLEANUP: dns: remove unused dns_stream_server struct member") may be
backported to ease the backport.
The stateless mode which was documented previously in the ACME example
is not convenient for all use cases.
First, when HAProxy generates the account key itself, you wouldn't be
able to put the thumbprint in the configuration, so you will have to get
the thumbprint and then reload.
Second, in the case you are using multiple account key, there are
multiple thumbprint, and it's not easy to know which one you want to use
when responding to the challenger.
This patch allows to configure a map in the acme section, which will be
filled by the acme task with the token corresponding to the challenge,
as the key, and the thumbprint as the value. This way it's easy to reply
the right thumbprint.
Example:
http-request return status 200 content-type text/plain lf-string "%[path,field(-1,/)].%[path,field(-1,/),map(virt@acme)]\n" if { path_beg '/.well-known/acme-challenge/' }
Define a new settings tune.quic.frontend.max-tot-window. It contains a
size argument which can be used to set a limit on the sum of all QUIC
connections congestion window. This is applied both on
quic_cc_path_set() and quic_cc_path_inc().
Note that this limitation cannot reduce a congestion window more than
the minimal limit which is set to 2 datagrams.
Use the newly defined cshared type to account for the sum of congestion
window of every QUIC connection. This value is stored in global counter
quic_mem_global defined in proto_quic module.
Define a new type "struct cshared". This can be used as a tool to
manipulate a global counter with thread-safety ensured. Each thread
would declare its thread-local cshared type, which would point to a
global counter.
Each thread can then add/substract value to their owned thread-local
cshared instance via cshared_add(). If the difference exceed a
configured limit, either positively or negatively, the global counter is
updated and thread-local instance is reset to 0. Each thread can safely
read the global counter value using cshared_read().
Congestion window is limit by a minimal and maximum values which can
never be exceeded. Min value is hardcoded to 2 datagrams as recommended
by the specification. Max value is specified via haproxy configuration.
These values must be respected each time the congestion window size is
adjusted. However, in some rare occasions, limit were not always
enforced. Fix this by implementing wrappers to set or increment the
congestion window. These functions ensure limits are always applied
after the operation.
Additionnally, wrappers also ensure that if window reached a new maximum
value, it is saved in <cwnd_last_max> field.
This should be backported up to 2.6, after a brief period of
observation.
There was some possible confusion between fields related to congestion
window size min and max limit which cannot be exceeded, and the maximum
value previously reached by the window.
Fix this by adopting a new naming scheme. Enforced limit are now renamed
<limit_max>/<limit_min>, while the previously reached max value is
renamed <cwnd_last_max>.
This should be backported up to 3.1.
TCP_NOTSENT_LOWAT is very convenient as it indicates when to report
EAGAIN on the sending side. It takes a margin on top of the estimated
window, meaning that it's no longer needed to store too many data in
socket buffers. Instead there's just enough to fill the send window
and a little bit of margin to cover the scheduling time to restart
sending. Experiments on a 100ms network have shown a 10-fold reduction
in the memory used by socket buffers by just setting this value to
tune.bufsize, without noticing any performance degradation. Theoretically
the responsiveness on multiplexed protocols such as H2 should also be
improved.
The CLI's "prompt" command toggles two distinct things:
- displaying or hiding the prompt at the beginning of the line
- single-command vs interactive mode
These are two independent concepts and the prompt mode doesn't
always cope well with tools that would like to upload data without
having to read the prompt on return. Also, the master command line
works in interactive mode by default with no prompt, which is not
consistent (and not convenient for tools). So let's start by splitting
the bit in two, and have a new APPCTX_CLI_ST1_INTER flag dedicated
to the interactive mode. For now the "prompt" command alone continues
to toggle the two at once.
We add __equals_0(NAME) which is only true if NAME is defined as zero,
and __def_as_empty(NAME) which is only true if NAME is defined as an
empty string.
Setting DEBUG_THREAD to 1 allows recording the lock history for each
thread. Tests have shown that (as predicted) the cost of updating a
single thread-local variable is not perceptible in the noise, especially
when compared to the cost of obtaining a lock. Since this can provide
useful value when debugging deadlocks, let's enable it by default when
threads are enabled.
This will display the lock labels and modes for each non-empty step
at the end of "show threads" when these are defined. This allows to
emit up to the last 8 locking operation for each thread on 64 bit
machines.
by only storing a word in each thread context, we can keep the history
of all taken/dropped locks by label. This is expected to be very cheap
and to permit to store up to 8 consecutive lock operations in 64 bits.
That should significantly help detect recursive locks as well as figure
what thread was likely to hinder another one waiting for a lock.
For now we only store the final state of the lock, we don't store the
attempt to get it. It's just a matter of space since we already need
4 ops (rd,sk,wr,un) which take 2 bits, leaving max 64 labels. We're
already around 45. We could also multiply by 5 and still keep 8 bits
total per lock, that would limit us to 51 locks max. It seems that
most of the time if we get a watchdog panic, anyway the victim thread
will be perfectly located so that we don't need a specific value for
this. Another benefit is that we perform a single memory write per
lock.
We now default the value to zero and make sure all tests properly take
care of values above zero. This is in preparation for supporting several
degrees of debugging.
Parse the Retry-After header in response and store it in order to use
the value as the next delay for the next retry, fallback to 3s if the
value couldn't be parse or does not exist.
Instead of always having to force IPv4 or IPv6, let's now also offer
"auto" which will only enable IPv6 if the system has a default gateway
for it. This means that properly configured dual-stack systems will
default to "ipv4,ipv6" while those lacking a gateway will only use
"ipv4". Note that no real connectivity test is performed, so firewalled
systems may still get it wrong and might prefer to rely on a manual
"ipv4" assignment.
In order to ease dual-stack deployments, we could at least try to
check if ipv6 seems to be reachable. For this we're adding a test
based on a UDP connect (no traffic) on port 53 to the base of
public addresses (2001::) and see if the connect() is permitted,
indicating that the routing table knows how to reach it, or fails.
Based on this result we're setting a global variable that other
subsystems might use to preset their defaults.
In order to ease troubleshooting and testing, the new "-4" command line
argument enforces queries and processing of "A" DNS records only, i.e.
those representing IPv4 addresses. This can be useful when a host lack
end-to-end dual-stack connectivity. This overrides the global
"dns-accept-family" directive and is equivalent to value "ipv4".
By default, DNS resolvers accept both IPv4 and IPv6 addresses. This can be
influenced by the "resolve-prefer" keywords on server lines as well as the
family argument to the "do-resolve" action, but that is only a preference,
which does not block the other family from being used when it's alone. In
some environments where dual-stack is not usable, stumbling on an unreachable
IPv6-only DNS record can cause significant trouble as it will replace a
previous IPv4 one which would possibly have continued to work till next
request. The "dns-accept-family" global option permits to enforce usage of
only one (or both) address families. The argument is a comma-delimited list
of the following words:
- "ipv4": query and accept IPv4 addresses ("A" records)
- "ipv6": query and accept IPv6 addresses ("AAAA" records)
When a single family is used, no request will be sent to resolvers for the
other family, and any response for the othe family will be ignored. The
default value is "ipv4,ipv6", which effectively enables both families.
