As a folow-up to f40f5401b9, explicitely
use atomic operations to set the prev and next fields, to make sure the
compiler can't assume anything about it, and just does it.
This should be backported after f40f5401b9 up to 2.8.
The USE_KTLS test is currently being done outside of the USE_OPENSSL
guard so disabling USE_OPENSSL still results in build failures on
libcs built with support for kernels before 4.17, because we enable
KTLS by default on linux. Let's move the KTLS block inside the
USE_OPENSSL guard instead.
No backport is needed since KTLS is only in 3.3.
This is a second attempt at fixing issues on 32bits systems which would
trigger the following BUG_ON() statement:
FATAL: bug condition "sizeof(struct shm_stats_file_object) != 544" matched at src/stats-file.c:825 shm_stats_file_object struct size changed, is is part of the exported API: ensure all precautions were taken (ie: shm_stats_file version change) before adjusting this
This is a drop-in replacement for d30b88a6c + 4693ee0ff, as suggested by
Willy.
Indeed, on supported platforms unsigned int can be assumed to be 4 bytes
long, and long can be assumed to be 8 bytes long. As such, the previous
attempt was overkill and added unecessary maintenance complexity which
could result in bugs if not used properly. Moreover, it would only
partially solve the issue, since on little endian vs big endian
architectures, the provisioned memory areas (originating from the same
shm stats file) could be read differently by the host.
Instead we fix the aligments issues, and this alone helps to ensure
struct memory consistency on 64 vs 32bits platforms. It was tested
on both i386 and i586.
last_change and last_sess counters are now stored as unsigned int, as
it helped to fix the alignment issues and they were found to be used
as 32bits integers anyway.
Thanks to Willy for problem analysis and the patch proposal.
No backport needed.
This reverts commit 466a603b59.
Due to the last 2 commits, this macro is now unused, and will probably
never be used, so let's get rid of that for now.
Several settings can be set to control stream multiplexing and
associated receive window. Previously, all of these settings were
configured using prefix "tune.quic.frontend.", despite being applied
blindly on both sides.
Fix this by duplicating these settings specific to frontend and backend
side. Options are also renamed to use the standardize prefix
"tune.quic.[be|fe].stream." notation.
Also, each option is individually renamed to better reflect its purpose
and hide technical details relative to QUIC transport parameter naming :
* max-data-size -> stream.rxbuf
* max-streams-bidi -> stream.max-concurrent
* stream-data-ratio -> stream.data-ratio
No need to backport.
Streamline max-idle-timeout option. Rename it to use the newer cohesive
naming scheme 'tune.quic.fe|be.'.
Two different fields were already defined in global struct. These fields
are moved into quic_tune along with other QUIC settings. However, no
parser was defined for backend option, this commit fixes this.
No need to backport this.
On frontend side, a quic_conn can have a dedicated FD or use the
listener one. These different modes can be activated via a global QUIC
tune setting.
This patch adjusts the option. First, it is renamed to the more
meaningful name 'tune.quic.fe.sock-per-conn'. Also, arguments are now
either 'default-on' or 'force-off'. The objective is to better highlight
reliationship with 'quic-socket' bind option.
The older option is deprecated and will be removed in 3.5.
A QUIC global tune setting is defined to be able to force Retry emission
prior to handshake. By definition, this ability is only supported by
QUIC servers, hence it is a frontend option only.
Rename the option to use "fe" prefix. The old option name is deprecated
and will be removed in 3.5
QUIC global memory can be limited across the entire process via a global
tune setting. Previously, this setting used to misleading "frontend"
prefix. As this is applied as a sum between all QUIC connections, both
from frontend and backend sides, remove the prefix. The new option name
is "tune.quic.mem.tx-max".
The older option name is deprecated and will be removed in 3.5.
This patch is similar to the previous one, except that it is focused on
Tx QUIC settings. It is now possible to toggle GSO and pacing on
frontend and backend sides independently.
As with previous patch, option are renamed to use "fe/be" unified
prefixes. This is part of the current serie of commits which unify QUI
settings. Older options are deprecated and will be removed on 3.5
release.
Various settings can be configured related to QUIC congestion controler.
This patch duplicates them to be able to set independent values on
frontend and backend sides.
As with previous patch, option are renamed to use "fe/be" unified
prefixes. This is part of the current serie of commits which unify QUIC
settings. Older options are deprecated and will be removed on 3.5
release.
Previously, QUIC glitches support was only implemented for frontend
side. Extend this so that the option can be specified separately both on
frontend and backend sides. Function _qcc_report_glitch() now retrieves
the relevant max value based on connection side.
In addition to this, option has been renamed to use "fe/be" prefixes.
This is part of the current serie of commits which unify QUIC settings.
Older options are deprecated and will be removed on 3.5 release.
Rename the option to quickly enable/disable every QUIC listeners. It now
takes an argument on/off. The documentation is extended to reflect the
fact that QUIC backend are not impacted by this option.
The older keyword is simply removed. Deprecation is considered
unnecessary as this setting is only useful during debugging.
A major reorganization of QUIC settings is going to be performed. One of
its objective is to clearly define options which can be separately
configured on frontend and backend proxy sides.
To implement this, quic_tune structure is extended to support fe and be
options. A set of macros/functions is also defined : it allows to
retrieve an option defined on both sides with unified code, based on
proxy side of a quic_conn/connection instance.
Avoid setting both el->prev and el->next on the same line.
The goal is to set both el->prev and el->next to el, but a naive
compiler, such as when we're using -O0, will set el->next first, then
will set el->prev to the value of el->next, but if we're unlucky,
el->next will have been set to something else by another thread.
So explicitely set both to what we want.
This should be backported up to 2.8.
As reported by @tianon on GH #3168, running haproxy on 32bits i386
platform would trigger the following BUG_ON() statement:
FATAL: bug condition "sizeof(struct shm_stats_file_object) != 544" matched at src/stats-file.c:825
shm_stats_file_object struct size changed, is is part of the exported API: ensure all precautions were taken (ie: shm_stats_file version change) before adjusting this
In fact, some efforts were already taken to ensure shm_stats_file_object
struct size remains consistent on 64 vs 32 bits platforms, since
shm_stats_file_object is part of the public API and directly exposed in
the stats file.
However, some parts were overlooked: some structs that are embedded in
shm_stats_file_object struct itself weren't using fixed-width integers,
and would sometime be unaligned. The result of this is that it was
up to the compiler (platform-dependent) to choose how to deal with such
ambiguities, which could cause the struct mapping/size to be inconsistent
from one platform to another.
Hopefully this was caught by the BUG_ON() statement and with the precious
help of @tianon
To fix this, we now use fixed-width integers everywhere for members
(and submembers) of shm_stats_file_object struct, and we use explicit
padding where missing to avoid automatic padding when we don't expect
one. As for the previous commit, we leverage FIXED_SIZE() and
FIXED_SIZE_ARRAY() macro to set the expected width for each integer
without causing build issues on platform that don't support larger
integers.
No backport needed, this feature was introduced during 3.3-dev.
freq-ctr struct is used by the shm_stats_file API, and more precisely,
it is used in the shm_stats_file_object struct for counters.
shm_stats_file_object struct requires to be plateform-independent, thus
we switch to using explicit size types (AKA fixed width integer types)
for freq-ctr, in the attempt to make freq-ctr size and memory mapping
consistent from one platform to another.
We cannot simply use fixed-width integer because some of them are
involved in atomic operations, and forcing a given width could
cause build issues on some platforms where atomic ops are not
implemented for large integers. Instead we leverage the FIXED_SIZE
macro to keep handling the integers as before, but forcing them to
be stored using expected number of bytes (unused bytes will simply
be ignored).
No change of behavior should be expected.
FIXED_SIZE() macro can be used to instruct the compiler that the struct
member named <name>, handled as <type>, must be stored using <size> bytes
and that even if the type used is actualler smaller than the expected size
FIXED_SIZE_ARRAY(), similar to FIXED_SIZE() but for arrays: it takes an
extra argument which is the number of members.
They may be used for portability concerns to ensure a structure mapping
remains consistent between platforms.
The previous commit switch from ncbuf to ncbmbuf as storage for received
CRYPTO frames. The latter ensures that buffering of such frames cannot
fail anymore due to gaps size.
Previously, extra mechanism were implemented on QUIC frames parsing
function to overcome the limitation of ncbuf on gaps size. Before
insertion, CRYPTO frames were stored in a temporary tree to order their
insertion. As this is not necessary anymore, this commit removes the
temporary tree insertion.
This commit is closely associated to the previous bug fix. As it
provides a neat optimization and code simplication, it can be backported
with it, but not in the next immediate release to spot potential
regression.
In QUIC, TLS handshake messages such as ClientHello are encapsulated in
CRYPTO frames. Each QUIC implementation can split the content in several
frames of random sizes. In fact, this feature is now used by several
clients, based on chrome so-called "Chaos protection" mechanism :
https://quiche.googlesource.com/quiche/+/cb6b51054274cb2c939264faf34a1776e0a5bab7
To support this, haproxy uses a ncbuf storage to store received CRYPTO
frames before passing it to the SSL library. However, this storage
suffers from a limitation as gaps between two filled blocks cannot be
smaller than 8 bytes. Thus, depending on the size of received CRYPTO
frames and their order, ncbuf may not be sufficient. Over time, several
mechanisms were implemented in haproxy QUIC frames parsing to overcome
the ncbuf limitation.
However, reports recently highlight that with some clients haproxy is
not able to deal with CRYPTO frames reception. In particular, this is
the case with the latest ngtcp2 release, which implements a similar
chaos protection mechanism via the following patch. It also seems that
this impacts haproxy interaction with firefox.
commit 89c29fd8611d5e6d2f6b1f475c5e3494c376028c
Author: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Mon Aug 4 22:48:06 2025 +0900
Crumble Client Initial CRYPTO (aka chaos protection)
To fix haproxy CRYPTO frames buffering once and for all, an alternative
non-contiguous buffer named ncbmbuf has been recently implemented. This
type does not suffer from gaps size limitation, albeit at the cost of a
small reduction in the size available for data storage.
Thus, the purpose of this current patch is to replace ncbuf with the
newer ncbmbuf for QUIC CRYPTO frames parsing. Now, ncbmb_add() is used
to buffer received frames which is guaranteed to suceed. The only
remaining case of error is if a received frame offset and length exceed
the ncbmbuf data storage, which would result in a CRYPTO_BUFFER_EXCEEDED
error code.
A notable behavior change when switching to ncbmbuf implementation is
that NCB_ADD_COMPARE mode cannot be used anymore during add. Instead,
crypto frame content received at a similar offset will be overwritten.
A final note regarding STREAM frames parsing. For now, it is considered
unnecessary to switch from ncbuf in this case. Indeed, QUIC clients does
not perform aggressive fragmentation for them. Keeping ncbuf ensure that
the data storage size is bigger than the equivalent ncbmbuf area.
This should fix github issue #3141.
This patch must be backported up to 2.6. It is first necessary to pick
the relevant commits for ncbmbuf implementation prior to it.
Implement ncbmb_advance() function for the ncbmbuf type. This allows to
remove bytes in front of the buffer, regardless of the existing gaps.
This is implemented by resetting the corresponding bits of the bitmap.
As the previous patch, this commit must be backported prior to the fix
to come on QUIC CRYPTO frames parsing.
Implement ncbmb_data() function for the ncbmbuf type. Its purpose is
similar to its ncbuf counterpart : it returns the size in bytes of data
starting at a specific offset until the next gap.
As the previous patch, this commit must be backported prior to the fix
to come on QUIC CRYPTO frames parsing.
This patch implements add operation for ncbmbuf type.
This function is simpler than its ncbuf counterpart. Indeed, for now
only NCB_ADD_OVERWRT mode is supported. This compromise has been chosen
as ncbmbuf will be first used for QUIC CRYPTO frames handling, which
does not mandate to compare existing filled blocks during insertion.
As the previous patch, this commit must be backported prior to the fix
to come on QUIC CRYPTO frames parsing.
Define ncbmbuf which is an alternative non-contiguous buffer
implementation. "bm" abbreviation stands for bitmap, which reflects how
gaps and filled blocks are encoded. The main purpose of this
implementation is to get rid of the ncbuf limitation regarding the
minimal size for gaps between two blocks of data.
This commit adds the new module ncbmbuf. Along with it, some utility
functions such as ncbmb_make(), ncbmb_init() and ncbmb_is_empty() are
defined. Public API of ncbmbuf will be extended in the following
patches.
This patch is not considered a bug fix. However, it will be required to
fix issue encountered on QUIC CRYPTO frames parsing. Thus, it will be
necessary to backport the current patch prior to the fix to come.
ncbuf is a module which provide a non-contiguous buffer type
implementation. This patch extracts some basic types related to it into
a new file ncbuf_common.h.
This patch will be useful to provide a new non-contiguous buffer
alternative implementation based on a bitmap.
This patch is not a bug fix. However, it is necessary for ncbmbuf
implementation which will be required to fix a QUIC issue on CRYPTO
frames parsing. This, it will be necessary to backport the current patch
prior to the fix to come.
Instead of having per-table expiration tasks, just use one per shard.
The task will now go through all the tables to expire entries. When a
table gets an expiration earlier than the one previously known, it will
be put in a mt-list, and the task will be responsible to put it into an
eb32, ordered based on the next expiration.
Each per-shard task will run on a different thread, so it should lead to
a better load distribution than the per-table tasks.
Add a new initcall stage, STG_INIT_2, for stuff to be called after
step_init_2() is called, so after we know for sure that global.nbthread
will be set.
Modify stick-tables stkt_late_init() to run at STG_INIT_2 instead of
STG_INIT, in anticipation for it to be enhanced and have a need for
global.nbthread.
In mt_list_delete(), if the element was not in a list, then n and p will
point to it, and so setting n->prev and n->next will be enough to unlock it.
Don't do it twice, as once it's been done the first time, another thread may
be working with it, and may have added it to a list already, and doing it
a second time can lead to list inconsistencies.
This should be backported up to 2.8.
The SSL counters were not handled at all for QUIC connections. This patch
implement ssl_sock_update_counters() extracting the code from ssl_sock.c
and call this function where applicable both in TLS/TCP and QUIC parts.
Must be backported as far as 2.8.
Better check that munmap() always works, otherwise it means we might
have miscalculated an address, and if it fails silently, it will eat
all the memory extremely quickly. Let's add a BUG_ON() on munmap's
return.
As reported by Christopher, in UAF mode memory release of aligned
objects as introduced in commit ef915e672a ("MEDIUM: pools: respect
pool alignment in allocations") does not work. The padding calculation
in the freeing code is no longer correct since it now depends on the
alignment, so munmap() fails on EINVAL. Fortunately we don't care much
about it since we know it's the low bits of the passed address, which
is much simpler to compute, since all mmaps are page-aligned.
There's no need to backport this, as this was introduced in 3.3.
The pcre2 matching requires an array of matches for grouping, that is
allocated when executing the rule by pre-processing it, and that is
immediately freed after use. This is quite inefficient and results in
annoying patterns in "show profiling" that attribute the allocations
to libpcre2 and the releases to haproxy.
A good suggestion from Dragan is to pre-allocate these per thread,
since the entry is not specific to a regex. In addition we're already
limited to MAX_MATCH matches so we don't even have the problem of
having to grow it while parsing nor processing.
The current patch adds a per-thread pair of init/deinit functions to
allocate a thread-local entry for that, and gets rid of the dynamic
allocations. It will result in cleaner memory management patterns and
slightly higher performance (+2.5%) when using pcre2.
A certificate that does not have the 'jwt' flag enabled cannot be used
for JWT validation. We now raise a specific return value so that such a
case can be identified.
This option can be used to enable the use of a given certificate for JWT
verification. It defaults to 'off' so certificates that are declared in
a crt-store and will be used for JWT verification must have a
"jwt on" option in the configuration.
This converter will be in charge of performing the same operation as the
'jwt_verify' one except that it takes a full-on pem certificate path
instead of a public key path as parameter.
The certificate path can be either provided directly as a string or via
a variable. This allows to use certificates that are not known during
init to perform token validation.
The jwt_verify converter will not take full-on certificates anymore
in favor of a new soon to come jwt_verify_cert. We might end up with a
new jwt_verify_hmac in the future as well which would allow to deprecate
the jwt_verify converter and remove the need for a specific internal
tree for public keys.
The logic to always look into the internal jwt tree by default and
resolve to locking the ckch tree as little as possible will also be
removed. This allows to get rid of the duplicated reference to
EVP_PKEYs, the one in the jwt tree entry and the one in the ckch_store.
By refactoring the HTX to remove the extra field, a bug was introduced in
the stream-connector part. The <kip> (known input payload) value of a sedesc
was moved to <kop> (knwon output payload) using the same sedesc. Of course,
this is totally wrong. <kip> value of a sedesc must be forwarded to the
opposite side.
In addition, the operation is performed in sc_conn_send(). In this function,
we manipulate the stream-connectors. So se_fwd_kip() function was changed to
use the stream-connectors directely.
Now, the function sc_ep_fwd_kip() is now called with the both
stream-connectors to properly forward <kip> from on side to the opposite
side.
The bug is 3.3-specific. No backport needed.
Thanks for previous changes, it is now possible to remove the <extra> field
from the HTX structure. HTX_FL_ALTERED_PAYLOAD flag is also removed because
it is now unsued.
For now, the HTX extra value is used to specify the known part, in bytes, of
the HTTP payload we will receive. It may concerne the full payload if a
content-length is specified or the current chunk for a chunk-encoded
message. The main purpose of this value is to be used on the opposite side
to be able to announce chunks bigger than a buffer. It can also be used to
check the validity of the payload on the sending path, to properly detect
too big or too short payload.
However, setting this information in the HTX message itself is not really
appropriate because the information is lost when the HTX message is consumed
and the underlying buffer released. So the producer must take care to always
add it in all HTX messages. it is especially an issue when the payload is
altered by a filter.
So to fix this design issue, the information will be moved in the sedesc. It
is a persistent area to save the information. In addition, to avoid the
ambiguity between what the producer say and what the consumer see, the
information will be splitted in two fields. In this patch, the fields are
added:
* kip : The known input payload length
* kop : The known output payload lenght
The producer will be responsible to set <kip> value. The stream will be
responsible to decrement <kip> and increment <kop> accordingly. And the
consumer will be responsible to remove consumed bytes from <kop>.
With this function we can now pass the desired default value for the
abortonclose option when neither the option nor its opposite were set.
Let's also take this opportunity for using it directly from the HTTP
analyser since there's no point in re-checking the proxy's mode there.
As discussed on https://github.com/orgs/haproxy/discussions/3146 and on
the mailing list, there's a marked preference for having abortonclose
enabled by default when relevant. The point being that with todays'
internet, the large majority of requests sent with a closed input
channel are aborted requests, and that it's pointless to waste resources
processing them.
This patch now considers both "option abortonclose" and its opposite
"no option abortonclose" to figure whether abortonclose is enabled or
disabled in a backend. When neither are set (thus not even inherited
from a defaults section), then it considers the proxy's mode, and HTTP
mode implies abortonclose by default.
This may make some legacy services fail starting with 3.3. In this case
it will be sufficient to add "no option abortonclose" in either the
affected backend or the defaults section it derives from. But for
internet-facing proxies it's better to stay with the option enabled.
In order to prepare for changing the way abortonclose works, let's
replace the direct flag check with a similarly named function
(proxy_abrt_close) which returns the on/off status of the directive
for the proxy. For now it simply reflects the flag's state.
Normally, when reading a full buffer, or exactly the requested size, it
is not really possible to know if the peer had closed immediately after,
and usually we don't care. There's a problematic case, though, which is
with SSL: the SSL layer reads in small chunks of a few bytes, and can
consume a client_hello this way, then start computation without knowing
yet that the client has aborted. In order to permit knowing more, we now
introduce a new read flag, CO_RFL_TRY_HARDER, which says that if we've
read up to the permitted limit and the flag is set, then we attempt one
extra byte using MSG_PEEK to detect whether the connection was closed
immediately after that content or not. The first use case will obviously
be related to SSL and client_hello, but it might possibly also make sense
on HTTP responses to detect a pending FIN at the end of a response (e.g.
if a close was already advertised).
Now it will be possible to query any thread's scheduler state, not
only the current one. This aims at simplifying the watchdog checks
for reported threads. The operation is now a simple atomic xchg.
Implement MT_LIST_POP_LOCKED(), that behaves as MT_LIST_POP() and
removes the first element from the list, if any, but keeps it locked.
This should be backported to 3.2, as it will be use in a bug fix in the
stick tables that affects 3.2 too.
Like "acme-vars", the "provider-name" in the acme section is used in
case of DNS-01 challenge and is sent to the dpapi sink.
This is used to pass the name of a DNS provider in order to chose the
DNS API to use.
This patch implements the cfg_parse_acme_vars_provider() which parses
either acme-vars or provider-name options and escape their strings.
Example:
$ ( echo "@@1 show events dpapi -w -0"; cat - ) | socat /tmp/master.sock - | cat -e
<0>2025-09-18T17:53:58.831140+02:00 acme deploy foobpar.pem thumbprint gDvbPL3w4J4rxb8gj20mGEgtuicpvltnTl6j1kSZ3vQ$
acme-vars "var1=foobar\"toto\",var2=var2"$
provider-name "godaddy"$
{$
"identifier": {$
"type": "dns",$
"value": "example.com"$
},$
"status": "pending",$
"expires": "2025-09-25T14:41:57Z",$
[...]
In the case of the dns-01 challenge, the agent that handles the
challenge might need some extra information which depends on the DNS
provider.
This patch introduces the "acme-vars" option in the acme section, which
allows to pass these data to the dpapi sink. The double quotes will be
escaped when printed in the sink.
Example:
global
setenv VAR1 'foobar"toto"'
acme LE
directory https://acme-staging-v02.api.letsencrypt.org/directory
challenge DNS-01
acme-vars "var1=${VAR1},var2=var2"
Would output:
$ ( echo "@@1 show events dpapi -w -0"; cat - ) | socat /tmp/master.sock - | cat -e
<0>2025-09-18T17:53:58.831140+02:00 acme deploy foobpar.pem thumbprint gDvbPL3w4J4rxb8gj20mGEgtuicpvltnTl6j1kSZ3vQ$
acme-vars "var1=foobar\"toto\",var2=var2"$
{$
"identifier": {$
"type": "dns",$
"value": "example.com"$
},$
"status": "pending",$
"expires": "2025-09-25T14:41:57Z",$
[...]
This patch looks huge, but it has a very simple goal: protect all
accessed to shared stats pointers (either read or writes), because
we know consider that these pointers may be NULL.
The reason behind this is despite all precautions taken to ensure the
pointers shouldn't be NULL when not expected, there are still corner
cases (ie: frontends stats used on a backend which no FE cap and vice
versa) where we could try to access a memory area which is not
allocated. Willy stumbled on such cases while playing with the rings
servers upon connection error, which eventually led to process crashes
(since 3.3 when shared stats were implemented)
Also, we may decide later that shared stats are optional and should
be disabled on the proxy to save memory and CPU, and this patch is
a step further towards that goal.
So in essence, this patch ensures shared stats pointers are always
initialized (including NULL), and adds necessary guards before shared
stats pointers are de-referenced. Since we already had some checks
for backends and listeners stats, and the pointer address retrieval
should stay in cpu cache, let's hope that this patch doesn't impact
stats performance much.
If we see that another thread is already busy trying to announce the
dropped counter, there's no point going there, so let's just skip all
that operation from sink_write() and avoid disturbing the other thread.
This results in a boost from 244 to 262k req/s.
Currently there's a small mistake in the way the trace function and
macros. The calling function name is known as a constant until the
macro and passed as-is to the __trace() function. That one needs to
know its length and will call ist() on it, resulting in a real call
to strlen() while that length was known before the call. Let's use
an ist instead of a const char* for __trace() and __trace_enabled()
so that we can now completely avoid calling strlen() during this
operation. This has significantly reduced the importance of
__trace_enabled() in perf top.
It is possible on at least Linux and FreeBSD to set the congestion control
algorithm to be used with outgoing connections, among the list of supported
and permitted ones. Let's expose this setting with "cc". Unknown or
forbidden algorithms will be ignored and the default one will continue to
be used.
It is possible on at least Linux and FreeBSD to set the congestion control
algorithm to be used with incoming connections, among the list of supported
and permitted ones. Let's expose this setting with "cc". Permission issues
might be reported (as warnings).
The C standard specifies that it's undefined behavior to dereference
NULL (even if you use & right after). The hand-rolled offsetof idiom
&(((s*)NULL)->f) is thus technically undefined. This clutters the
output of UBSan and is simple to fix: just use the real offsetof when
it's available.
Note that there's no clear statement about this point in the spec,
only several points which together converge to this:
- From N3220, 6.5.3.4:
A postfix expression followed by the -> operator and an identifier
designates a member of a structure or union object. The value is
that of the named member of the object to which the first expression
points, and is an lvalue.
- From N3220, 6.3.2.1:
An lvalue is an expression (with an object type other than void) that
potentially designates an object; if an lvalue does not designate an
object when it is evaluated, the behavior is undefined.
- From N3220, 6.5.4.4 p3:
The unary & operator yields the address of its operand. If the
operand has type "type", the result has type "pointer to type". If
the operand is the result of a unary * operator, neither that operator
nor the & operator is evaluated and the result is as if both were
omitted, except that the constraints on the operators still apply and
the result is not an lvalue. Similarly, if the operand is the result
of a [] operator, neither the & operator nor the unary * that is
implied by the [] is evaluated and the result is as if the & operator
were removed and the [] operator were changed to a + operator.
=> In short, this is saying that C guarantees these identities:
1. &(*p) is equivalent to p
2. &(p[n]) is equivalent to p + n
As a consequence, &(*p) doesn't result in the evaluation of *p, only
the evaluation of p (and similar for []). There is no corresponding
special carve-out for ->.
See also: https://pvs-studio.com/en/blog/posts/cpp/0306/
After this patch, HAProxy can run without crashing after building w/
clang-19 -fsanitize=undefined -fno-sanitize=function,alignment
This is ebtree commit bd499015d908596f70277ddacef8e6fa998c01d5.
Signed-off-by: Willy Tarreau <w@1wt.eu>
This is ebtree commit 5211c2f71d78bf546f5d01c8d3c1484e868fac13.
We'll use this to improve the definition of container_of(). Let's define
it if it does not exist. We can rely on __builtin_offsetof() on recent
enough compilers.
This is ebtree commit 1ea273e60832b98f552b9dbd013e6c2b32113aa5.
Signed-off-by: Willy Tarreau <w@1wt.eu>
This is ebtree commit 69b2ef57a8ce321e8de84486182012c954380401.
From 'man gcc': passing 0 as the argument to "__builtin_ctz" or
"__builtin_clz" invokes undefined behavior. This triggers UBsan
in HAProxy.
[wt: tested in treebench and verified not to cause any performance
regression with opstime-u32 nor stress-u32]
Signed-off-by: Willy Tarreau <w@1wt.eu>
This is ebtree commit 8c29daf9fa6e34de8c7684bb7713e93dcfe09029.
Signed-off-by: Willy Tarreau <w@1wt.eu>
This is ebtree commit cf3b93736cb550038325e1d99861358d65f70e9a.
While the previous optimizations couldn't be preserved due to the
possibility of out-of-bounds accesses, at least the prefetch is useful.
A test on treebench shows that for 64k short strings, the lookup time
falls from 276 to 199ns per lookup (28% savings), and the insert falls
from 311 to 296ns (4.9% savings), which are pretty respectable, so
let's do this.
This is ebtree commit b44ea5d07dc1594d62c3a902783ed1fb133f568d.
It looks like __builtin_prefetch() appeared in gcc-3.1 as there's no
mention of it in 3.0's doc. Let's replace it with eb_prefetch() which
maps to __builtin_prefetch() on supported compilers and falls back to
the usual do{}while(0) on other ones. It was tested to properly build
with tcc as well as gcc-2.95.
This is ebtree commit 7ee6ede56a57a046cb552ed31302b93ff1a21b1a.
Similar to previous patches, let's improve the insert() descent loop to
avoid discovering mandatory data too late. The change here is even
simpler than previous ones, a prefetch was installed and troot is
calculated before last instruction in a speculative way. This was enough
to gain +50% insertion rate on random data.
This is ebtree commit e893f8cc4d44b10f406b9d1d78bd4a9bd9183ccf.
This is the same principles as for the latest improvements made on
integer trees. Applying the same recipes made the ebmb_lookup()
function jump from 10.07 to 12.25 million lookups per second on a
10k random values tree (+21.6%).
It's likely that the ebmb_lookup_longest() code could also benefit
from this, though this was neither explored nor tested.
This is ebtree commit a159731fd6b91648a2fef3b953feeb830438c924.
In the loop we can help the compiler build slightly more efficient code
by placing an unlikely() around the leaf test. This shows a consistent
0.5% performance gain both on eb32 and eb64.
This is ebtree commit 6c9cdbda496837bac1e0738c14e42faa0d1b92c4.
This one was previously used to preload from the node and keep a copy
in a register on i386 machines with few registers. With the new more
optimal code it's totally useless, so let's get rid of it. By the way
the 64 bit code didn't use that at all already.
This is ebtree commit 1e219a74cfa09e785baf3637b6d55993d88b47ef.
Instead of shifting the XOR value right and comparing it to 1, which
roughly requires 2 sequential instructions, better test if the XOR has
any bit above the current bit, which means any bit set among those
strictly higher, or in other words that XOR & (-bit << 1) is non-zero.
This is one less instruction in the fast path and gives another nice
performance gain on random keys (in million lookups/s):
eb32 1k: 33.17 -> 37.30 +12.5%
10k: 15.74 -> 17.08 +8.51%
100k: 8.00 -> 9.00 +12.5%
eb64 1k: 34.40 -> 38.10 +10.8%
10k: 16.17 -> 17.10 +5.75%
100k: 8.38 -> 8.87 +5.85%
This is ebtree commit c942a2771758eed4f4584fe23cf2914573817a6b.
The current code calculates the next troot based on a calculation.
This was efficient when the algorithm was developed many years ago
on K6 and K7 CPUs running at low frequencies with few registers and
limited branch prediction units but nowadays with ultra-deep pipelines
and high latency memory that's no longer efficient, because the CPU
needs to have completed multiple operations before knowing which
address to start fetching from. It's sad because we only have two
branches each time but the CPU cannot know it. In addition, the
calculation is performed late in the loop, which does not help the
address generation unit to start prefetching next data.
Instead we should help the CPU by preloading data early from the node
and calculing troot as soon as possible. The CPU will be able to
postpone that processing until the dependencies are available and it
really needs to dereference it. In addition we must absolutely avoid
serializing instructions such as "(a >> b) & 1" because there's no
way for the compiler to parallelize that code nor for the CPU to pre-
process some early data.
What this patch does is relatively simple:
- we try to prefetch the next two branches as soon as the
node is known, which will help dereference the selected node in
the next iteration; it was shown that it only works with the next
changes though, otherwise it can reduce the performance instead.
In practice the prefetching will start a bit later once the node
is really in the cache, but since there's no dependency between
these instructions and any other one, we let the CPU optimize as
it wants.
- we preload all important data from the node (next two branches,
key and node.bit) very early even if not immediately needed.
This is cheap, it doesn't cause any pipeline stall and speeds
up later operations.
- we pre-calculate 1<<bit that we assign into a register, so as
to avoid serializing instructions when deciding which branch to
take.
- we assign the troot based on a ternary operation (or if/else) so
that the CPU knows upfront the two possible next addresses without
waiting for the end of a calculation and can prefetch their contents
every time the branch prediction unit guesses right.
Just doing this provides significant gains at various tree sizes on
random keys (in million lookups per second):
eb32 1k: 29.07 -> 33.17 +14.1%
10k: 14.27 -> 15.74 +10.3%
100k: 6.64 -> 8.00 +20.5%
eb64 1k: 27.51 -> 34.40 +25.0%
10k: 13.54 -> 16.17 +19.4%
100k: 7.53 -> 8.38 +11.3%
The performance is now much closer to the sequential keys. This was
done for all variants ({32,64}{,i,le,ge}).
Another point, the equality test in the loop improves the performance
when looking up random keys (since we don't need to reach the leaf),
but is counter-productive for sequential keys, which can gain ~17%
without that test. However sequential keys are normally not used with
exact lookups, but rather with lookup_ge() that spans a time frame,
and which does not have that test for this precise reason, so in the
end both use cases are served optimally.
It's interesting to note that everything here is solely based on data
dependencies, and that trying to perform *less* operations upfront
always ends up with lower performance (typically the original one).
This is ebtree commit 05a0613e97f51b6665ad5ae2801199ad55991534.
Let's explicitly mention that fe_counters_shared_tg and
be_counters_shared_tg structs are embedded in shm_stats_file_object
struct so any change in those structs will result in shm stats file
incompatibility between processes, thus extra precaution must be
taken when making changes to them.
Note that the provisionning made in shm_stats_file_object struct could
be used to add members to {fe,be}_counters_shared_tg without changing
shm_stats_file_object struct size if needed in order to preserve
shm stats file version.
The variables trees use the immediate cebtree API, better use the
item one which is more expressive and safer. The "node" field was
renamed to "name_node" to avoid any ambiguity.
Previously the conn_hash_node was placed outside the connection due
to the big size of the eb64_node that could have negatively impacted
frontend connections. But having it outside also means that one
extra allocation is needed for each backend connection, and that one
memory indirection is needed for each lookup.
With the compact trees, the tree node is smaller (16 bytes vs 40) so
the overhead is much lower. By integrating it into the connection,
We're also eliminating one pointer from the connection to the hash
node and one pointer from the hash node to the connection (in addition
to the extra object bookkeeping). This results in saving at least 24
bytes per total backend connection, and only inflates connections by
16 bytes (from 240 to 256), which is a reasonable compromise.
Tests on a 64-core EPYC show a 2.4% increase in the request rate
(from 2.08 to 2.13 Mrps).
Idle connection trees currently require a 56-byte conn_hash_node per
connection, which can be reduced to 32 bytes by moving to ceb64. While
ceb64 is theoretically slower, in practice here we're essentially
dealing with trees that almost always contain a single key and many
duplicates. In this case, ceb64 insert and lookup functions become
faster than eb64 ones because all duplicates are a list accessed in
O(1) while it's a subtree for eb64. In tests it is impossible to tell
the difference between the two, so it's worth reducing the memory
usage.
This commit brings the following memory savings to conn_hash_node
(one per backend connection), and to srv_per_thread (one per thread
and per server):
struct before after delta
conn_hash_nodea 56 32 -24
srv_per_thread 96 72 -24
The delicate part is conn_delete_from_tree(), because we need to
know the tree root the connection is attached to. But thanks to
recent cleanups, it's now clear enough (i.e. idle/safe/avail vs
session are easy to distinguish).
We'll soon need to choose the server's root based on the connection's
flags, and for this we'll need the thread it's attached to, which is
not always the current one. This patch simply passes the thread number
from all callers. They know it because they just set the idle_conns
lock on it prior to calling the function.
The proxy struct has several small holes that deserved being plugged by
moving a few fields around. Now we're down to 3056 from 3072 previously,
and the remaining holes are small.
At the moment, compared to before this series, we're seeing these
sizes:
type\size 7d554ca62 current delta
listener 752 704 -48 (-6.4%)
server 4032 3840 -192 (-4.8%)
proxy 3184 3056 -128 (-4%)
stktable 3392 3328 -64 (-1.9%)
Configs with many servers have shrunk by about 4% in RAM and configs
with many proxies by about 3%.
The struct server still has a lot of holes and padding that make it
quite big. By moving a few fields aronud between areas which do not
interact (e.g. boot vs aligned areas), it's quite easy to plug some
of them and/or to arrange larger ones which could be reused later with
a bit more effort. Here we've reduced holes by 40 bytes, allowing the
struct to shrink by one more cache line (64 bytes). The new size is
3840 bytes.
The server ID is currently stored as a 32-bit int using an eb32 tree.
It's used essentially to find holes in order to automatically assign IDs,
and to detect duplicates. Let's change this to use compact trees instead
in order to save 24 bytes in struct server for this node, plus 8 bytes in
struct proxy. The server struct is still 3904 bytes large (due to
alignment) and the proxy struct is 3072.
The listener ID is currently stored as a 32-bit int using an eb32 tree.
It's used essentially to find holes in order to automatically assign IDs,
and to detect duplicates. Let's change this to use compact trees instead
in order to save 24 bytes in struct listener for this node, plus 8 bytes
in struct proxy. The struct listener is now 704 bytes large, and the
struct proxy 3080.
The proxy ID is currently stored as a 32-bit int using an eb32 tree.
It's used essentially to find holes in order to automatically assign IDs,
and to detect duplicates. Let's change this to use compact trees instead
in order to save 24 bytes in struct proxy for this node, plus 8 bytes in
the root (which is static so not much relevant here). Now the proxy is
3088 bytes large.
This was previously achieved via the generic get_next_id() but we'll soon
get rid of generic ID trees so let's have a dedicated server_get_next_id().
As a bonus it reduces the exposure of the tree's root outside of the functions.
This was previously achieved via the generic get_next_id() but we'll soon
get rid of generic ID trees so let's have a dedicated listener_get_next_id().
As a bonus it reduces the exposure of the tree's root outside of the functions.
This is used to index the proxy's name and it contains a copy of the
pointer to the proxy's name in <id>. Changing that for a ceb_node placed
just before <id> saves 32 bytes to the struct proxy, which is now 3112
bytes large.
Here we need to continue to support duplicates since they're still
allowed between type-incompatible proxies.
Interestingly, the use of cebis_next_dup() instead of cebis_next() in
proxy_find_by_name() allows us to get rid of an strcmp() that was
performed for each use_backend rule. A test with a large config
(100k backends) shows that we can get 3% extra performance on a
config involving a static use_backend rule (3.09M to 3.18M rps),
and even 4.5% on a dynamic rule selecting a random backend (2.47M
to 2.59M).
This member is used to index the hostname_dn contents for DNS resolution.
Let's replace it with a cebis_tree to save another 32 bytes (24 for the
node + 8 by avoiding the duplication of the pointer). The struct server is
now at 3904 bytes.
This is used to index the server name and it contains a copy of the
pointer to the server's name in <id>. Changing that for a ceb_node placed
just before <id> saves 32 bytes to the struct server, which remains 3968
bytes large due to alignment. The proxy struct shrinks by 8 bytes to 3144.
It's worth noting that the current way duplicate names are handled remains
based on the previous mechanism where dups were permitted. Ideally we
should now reject them during insertion and use unique key trees instead.
This contains the text representation of the server's address, for use
with stick-tables with "srvkey addr". Switching them to a compact node
saves 24 more bytes from this structure. The key was moved to an external
pointer "addr_key" right after the node.
The server struct is now 3968 bytes (down from 4032) due to alignment, and
the proxy struct shrinks by 8 bytes to 3152.
The current guid struct size is 56 bytes. Once reduced using compact
trees, it goes down to 32 (almost half). We're not on a critical path
and size matters here, so better switch to this.
It's worth noting that the name part could also be stored in the
guid_node at the end to save 8 extra byte (no pointer needed anymore),
however the purpose of this struct is to be embedded into other ones,
which is not compatible with having a dynamic size.
Affected struct sizes in bytes:
Before After Diff
server 4032 4032 0*
proxy 3184 3160 -24
listener 752 728 -24
*: struct server is full of holes and padding (176 bytes) and is
64-byte aligned. Moving the guid_node elsewhere such as after sess_conn
reduces it to 3968, or one less cache line. There's no point in moving
anything now because forthcoming patches will arrange other parts.
cebs_tree are 24 bytes smaller than ebst_tree (16B vs 40B), and pattern
references are only used during map/acl updates, so their storage is
pure loss between updates (which most of the time never happen). By
switching their indexing to compact trees, we can save 16 to 24 bytes
per entry depending on alightment (here it's 24 per struct but 16
practical as malloc's alignment keeps 8 unused).
Tested on core i7-8650U running at 3.0 GHz, with a file containing
17.7M IP addresses (16.7M different):
$ time ./haproxy -c -f acl-ip.cfg
Save 280 MB RAM for 17.7M IP addresses, and slightly speeds up the
startup (5.8%, from 19.2s to 18.2s), a part of which possible being
attributed to having to write less memory. Note that this is on small
strings. On larger ones such as user-agents, ebtree doesn't reread
the whole key and might be more efficient.
Before:
RAM (VSZ/RSS): 4443912 3912444
real 0m19.211s
user 0m18.138s
sys 0m1.068s
Overhead Command Shared Object Symbol
44.79% haproxy haproxy [.] ebst_insert
25.07% haproxy haproxy [.] ebmb_insert_prefix
3.44% haproxy libc-2.33.so [.] __libc_calloc
2.71% haproxy libc-2.33.so [.] _int_malloc
2.33% haproxy haproxy [.] free_pattern_tree
1.78% haproxy libc-2.33.so [.] inet_pton4
1.62% haproxy libc-2.33.so [.] _IO_fgets
1.58% haproxy libc-2.33.so [.] _int_free
1.56% haproxy haproxy [.] pat_ref_push
1.35% haproxy libc-2.33.so [.] malloc_consolidate
1.16% haproxy libc-2.33.so [.] __strlen_avx2
0.79% haproxy haproxy [.] pat_idx_tree_ip
0.76% haproxy haproxy [.] pat_ref_read_from_file
0.60% haproxy libc-2.33.so [.] __strrchr_avx2
0.55% haproxy libc-2.33.so [.] unlink_chunk.constprop.0
0.54% haproxy libc-2.33.so [.] __memchr_avx2
0.46% haproxy haproxy [.] pat_ref_append
After:
RAM (VSZ/RSS): 4166108 3634768
real 0m18.114s
user 0m17.113s
sys 0m0.996s
Overhead Command Shared Object Symbol
38.99% haproxy haproxy [.] cebs_insert
27.09% haproxy haproxy [.] ebmb_insert_prefix
3.63% haproxy libc-2.33.so [.] __libc_calloc
3.18% haproxy libc-2.33.so [.] _int_malloc
2.69% haproxy haproxy [.] free_pattern_tree
1.99% haproxy libc-2.33.so [.] inet_pton4
1.74% haproxy libc-2.33.so [.] _IO_fgets
1.73% haproxy libc-2.33.so [.] _int_free
1.57% haproxy haproxy [.] pat_ref_push
1.48% haproxy libc-2.33.so [.] malloc_consolidate
1.22% haproxy libc-2.33.so [.] __strlen_avx2
1.05% haproxy libc-2.33.so [.] __strcmp_avx2
0.80% haproxy haproxy [.] pat_idx_tree_ip
0.74% haproxy libc-2.33.so [.] __memchr_avx2
0.69% haproxy libc-2.33.so [.] __strrchr_avx2
0.69% haproxy libc-2.33.so [.] _IO_getline_info
0.62% haproxy haproxy [.] pat_ref_read_from_file
0.56% haproxy libc-2.33.so [.] unlink_chunk.constprop.0
0.56% haproxy libc-2.33.so [.] cfree@GLIBC_2.2.5
0.46% haproxy haproxy [.] pat_ref_append
If the addresses are totally disordered (via "shuf" on the input file),
we see both implementations reach exactly 68.0s (slower due to much
higher cache miss ratio).
On large strings such as user agents (1 million here), it's now slightly
slower (+9%):
Before:
real 0m2.475s
user 0m2.316s
sys 0m0.155s
After:
real 0m2.696s
user 0m2.544s
sys 0m0.147s
But such patterns are much less common than short ones, and the memory
savings do still count.
Note that while it could be tempting to get rid of the list that chains
all these pat_ref_elt together and only enumerate them by walking along
the tree to save 16 extra bytes per entry, that's not possible due to
the problem that insertion ordering is critical (think overlapping regex
such as /index.* and /index.html). Currently it's not possible to proceed
differently because patterns are first pre-loaded into the pat_ref via
pat_ref_read_from_file_smp() and later indexed by pattern_read_from_file(),
which has to only redo the second part anyway for maps/acls declared
multiple times.
The support for duplicates is necessary for various use cases related
to config names, so let's upgrade to the latest version which brings
this support. This updates the cebtree code to commit 808ed67 (tag
0.5.0). A few tiny adaptations were needed:
- replace a few ceb_node** with ceb_root** since pointers are now
tagged ;
- replace cebu*.h with ceb*.h since both are now merged in the same
include file. This way we can drop the unused cebu*.h files from
cebtree that are provided only for compatibility.
- rename immediate storage functions to cebXX_imm_XXX() as per the API
change in 0.5 that makes immediate explicit rather than implicit.
This only affects vars and tools.c:copy_file_name().
The tests continue to work.
If an ocsp response is set to be updated automatically and some
certificate or CA updates are performed on the CLI, if the CLI update
happens while the OCSP response is being updated and is then detached
from the udapte tree, it might be wrongly inserted into the update tree
in 'ssl_sock_load_ocsp', and then reinserted when the update finishes.
The update tree then gets corrupted and we could end up crashing when
accessing other nodes in the ocsp response update tree.
This patch must be backported up to 2.8.
This patch fixes GitHub #3100.
An eb tree was used to anticipate for infinite amount of custom log steps
configured at a proxy level. In turns out this makes no sense to configure
that much logging steps for a proxy, and the cost of the eb tree is non
negligible in terms of memory footprint, especially when used in a default
section.
Instead, let's use a simple bitmask, which allows up to 64 logging steps
configured at proxy level. If we lack space some day (and need more than
64 logging steps to be configured), we could simply modify
"struct log_steps" to spread the bitmask over multiple 64bits integers,
minor some adjustments where the mask is set and checked.
