If haproxy fails to start and emits an alert, then it can be useful
to have it also emit the version and the path used to load it. Some
users may be mistakenly launching the wrong binary due to a misconfigured
PATH variable and this will save them some troubleshooting time when it
reports that some keywords are not understood.
What we do here is that we *try* to extract the binary name from the
AUX vector on glibc, and we report this as a NOTICE tag before the
very first alert is emitted.
Since some systems switched to service managers which hide all warnings
by default, some users are not aware of some possibly important warnings
and get caught too late with errors that could have been detected earlier.
This patch adds a new global keyword, "zero-warning" and an equivalent
command-line option "-dW" to refuse to start in case any warning is
detected. It is recommended to use these with configurations that are
managed by humans in order to catch mistakes very early.
This helps quickly checking if the config produces any warning. For
this we reuse the "warned" bit field to add a new WARN_ANY bit that is
set by ha_warning(). The rest of the bit field was also cleaned from
unused bits.
This reverts commit 1c306aa84d.
It breaks the build on all non-glibc platforms. I got confused by the
man page (which possibly is the most confusing man page I've ever read
about a standard libc function) and mistakenly understood that random_r
was portable, especially since it appears in latest freebsd source as
well but not in released versions, and with a slightly different API :-/
We need to find a different solution with a fallback. Among the
possibilities, we may reintroduce this one with a fallback relying on
locking around the standard functions, keeping fingers crossed for no
other library function to call them in parallel, or we may also provide
our own PRNG, which is not necessarily more difficult than working
around the totally broken up design of the portable API.
As mentioned in previous patch, the random number generator was never
made thread-safe, which used not to be a problem for health checks
spreading, until the uuid sample fetch function appeared. Currently
it is possible for two threads or processes to produce exactly the
same UUID. In fact it's extremely likely that this will happen for
processes, as can be seen with this config:
global
nbproc 8
frontend f
bind :4445
mode http
log stdout daemon format raw
log-format "%[uuid] %pid"
redirect location /
It typically produces this log:
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30645
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30641
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30644
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30639
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30646
07764439-c24d-4e6f-a5a6-0138be59e7a8 30645
07764439-c24d-4e6f-a5a6-0138be59e7a8 30639
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30643
07764439-c24d-4e6f-a5a6-0138be59e7a8 30646
b6773fdd-678f-4d04-96f2-4fb11ad15d6b 30646
551ce567-0bfb-4bbd-9b58-cdc7e9365325 30642
07764439-c24d-4e6f-a5a6-0138be59e7a8 30642
What this patch does is to use a distinct per-thread and per-process
seed to make sure the same sequences will not appear, and will then
extend these seeds by "burning" a number of randoms that depends on
the global random seed, the thread ID and the process ID. This adds
roughly 20 extra bits of randomness, resulting in 52 bits total per
thread and per process.
It only takes a few milliseconds to burn these randoms and given
that threads start with a different seed, we know they will not
catch each other. So these random extra bits are essentially added
to ensure randomness between boots and cluster instances.
This replaces all uses of random() with ha_random() which uses the
thread-local state.
This must be backported as far as 2.0 or any version having the
UUID sample-fetch function since it's the main victim here.
It's important to note that this patch, in addition to depending on
the previous one "BUG/MEDIUM: init: initialize the random pool a bit
better", also depends on the preceeding build fixes to address a
circular dependency issue in the include files that prevented it
from building. Part or all of these patches may need to be backported
or adapted as well.
Since the UUID sample fetch was created, some people noticed that in
certain virtualized environments they manage to get exact same UUIDs
on different instances started exactly at the same moment. It turns
out that the randoms were only initialized to spread the health checks
originally, not to provide "clean" randoms.
This patch changes this and collects more randomness from various
sources, including existing randoms, /dev/urandom when available,
RAND_bytes() when OpenSSL is available, as well as the timing for such
operations, then applies a SHA1 on all this to keep a 160 bits random
seed available, 32 of which are passed to srandom().
It's worth mentioning that there's no clean way to pass more than 32
bits to srandom() as even initstate() provides an opaque state that
must absolutely not be tampered with since known implementations
contain state information.
At least this allows to have up to 4 billion different sequences
from the boot, which is not that bad.
Note that the thread safety was still not addressed, which is another
issue for another patch.
This must be backported to all versions containing the UUID sample
fetch function, i.e. as far as 2.0.
The global listener queue code and declarations were still lying in
haproxy.c while not needed there anymore at all. This complicates
the code for no reason. As a result, the global_listener_queue_task
and the global_listener_queue were made static.
HAProxy doesn't need to call executables at run time (except when using
external checks which are strongly recommended against), and is even expected
to isolate itself into an empty chroot. As such, there basically is no valid
reason to allow a setuid executable to be called without the user being fully
aware of the risks. In a situation where haproxy would need to call external
checks and/or disable chroot, exploiting a vulnerability in a library or in
haproxy itself could lead to the execution of an external program. On Linux
it is possible to lock the process so that any setuid bit present on such an
executable is ignored. This significantly reduces the risk of privilege
escalation in such a situation. This is what haproxy does by default. In case
this causes a problem to an external check (for example one which would need
the "ping" command), then it is possible to disable this protection by
explicitly adding this directive in the global section. If enabled, it is
possible to turn it back off by prefixing it with the "no" keyword.
Before the option:
$ socat - /tmp/sock1 <<< "expert-mode on; debug dev exec sudo /bin/id"
uid=0(root) gid=0(root) groups=0(root
After the option:
$ socat - /tmp/sock1 <<< "expert-mode on; debug dev exec sudo /bin/id"
sudo: effective uid is not 0, is /usr/bin/sudo on a file system with the
'nosuid' option set or an NFS file system without root privileges?
Some concerns are regularly raised about the risk to inherit some Lua
files which make use of a fork (e.g. via os.execute()) as well as
whether or not some of bugs we fix might or not be exploitable to run
some code. Given that haproxy is event-driven, any foreground activity
completely stops processing and is easy to detect, but background
activity is a different story. A Lua script could very well discretely
fork a sub-process connecting to a remote location and taking commands,
and some injected code could also try to hide its activity by creating
a process or a thread without blocking the rest of the processing. While
such activities should be extremely limited when run in an empty chroot
without any permission, it would be better to get a higher assurance
they cannot happen.
This patch introduces something very simple: it limits the number of
processes and threads to zero in the workers after the last thread was
created. By doing so, it effectively instructs the system to fail on
any fork() or clone() syscall. Thus any undesired activity has to happen
in the foreground and is way easier to detect.
This will obviously break external checks (whose concept is already
totally insecure), and for this reason a new option
"insecure-fork-wanted" was added to disable this protection, and it
is suggested in the fork() error report from the checks. It is
obviously recommended not to use it and to reconsider the reasons
leading to it being enabled in the first place.
If for any reason we fail to disable forks, we still start because it
could be imaginable that some operating systems refuse to set this
limit to zero, but in this case we emit a warning, that may or may not
be reported since we're after the fork point. Ideally over the long
term it should be conditionned by strict-limits and cause a hard fail.
this patch introduces a strict-limits parameter which enforces the
setrlimit setting instead of a warning. This option can be forcingly
disable with the "no" keyword.
The general aim of this patch is to avoid bad surprises on a production
environment where you change the maxconn for example, a new fd limit is
calculated, but cannot be set because of sysfs setting. In that case you
might want to have an explicit failure to be aware of it before seeing
your traffic going down. During a global rollout it is also useful to
explictly fail as most progressive rollout would simply check the
general health check of the process.
As discussed, plan to use the strict by default mode starting from v2.3.
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
Instead of using the same type for regular linked lists and "autolocked"
linked lists, use a separate type, "struct mt_list", for the autolocked one,
and introduce a set of macros, similar to the LIST_* macros, with the
MT_ prefix.
When we use the same entry for both regular list and autolocked list, as
is done for the "list" field in struct connection, we know have to explicitely
cast it to struct mt_list when using MT_ macros.
Most of times, when a keyword is added in proxy section or on the server line,
we need to have a post-parser callback to check the config validity for the
proxy or the server which uses this keyword.
It is possible to register a global post-parser callback. But all these
callbacks need to loop on the proxies and servers to do their job. It is neither
handy nor efficient. Instead, it is now possible to register per-proxy and
per-server post-check callbacks.
Most of times, when any allocation is done during configuration parsing because
of a new keyword in proxy section or on the server line, we must add a call in
the deinit() function to release allocated ressources. It is now possible to
register a post-deinit callback because, at this stage, the proxies and the
servers are already releases.
Now, it is possible to register deinit callbacks per-proxy or per-server. These
callbacks will be called for each proxy and server before releasing them.
It was announced for the 2.1. Following keywords are now unsupported:
* reqadd, reqallow, reqiallow, reqdel, reqidel, reqdeny, reqideny, reqpass,
reqipass, reqrep, reqirep reqtarpit, reqitarpit
* rspadd, rspdel, rspidel, rspdeny, rspideny, rsprep, rspirep
a fatal error is emitted if one of these keyword is found during the
configuraion parsing.
Since commit 81492c989 ("MINOR: threads: flatten the per-thread cpu-map"),
we don't keep the proc*thread matrix anymore to represent the full binding
possibilities, but only the proc and thread ones. The problem is that the
per-process binding is not the same for each thread and for the process,
and the proc[] array was assumed to store the per-proc first thread value
when doing this change. Worse, the logic present there tries to deal with
thread ranges and process ranges in a way which automatically exclused the
other possibility (since ranges cannot be used on both) but as such fails
to apply changes if neither the process nor the thread is expressed as a
range.
The real problem comes from the fact that specifying cpu-map 1/1 doesn't
yet reveal if the per-process mask or the per-thread mask needs to be
updated. In practice it's the thread one but then the current storage
doesn't allow to store the binding of the first thread of each other
process in nbproc>1 configurations.
When removing the proc*thread matrix, what ought to have been kept was
both the thread column for process 1 and the process line for threads 1,
but instead only the thread column was kept. This patch reintroduces the
storage of the configuration for the first thread of each process so that
it is again possible to store either the per-thread or per-process
configuration.
As a partial workaround for existing configurations, it is possible to
systematically indicate at least two processes or two threads at once
and map them by pairs or more so that at least two values are present
in the range. E.g :
# set processes 1-4 to cpus 0-3 :
cpu-map auto:1-4/1 0 1 2 3
# or:
cpu-map 1-2/1 0 1
cpu-map 2-3/1 2 3
# set threads 1-4 to cpus 0-3 :
cpu-map auto:1/1-4 0 1 2 3
# or :
cpu-map 1/1-2 0 1
cpu-map 3/3-4 2 3
This fix must be backported to 2.0.
As reported in GH issue #99, when hard-stop-after triggers and threads
are in use, the chance that any thread releases the resources in use by
the other ones is non-null. Thus no thread should be allowed to deinit()
nor exit by itself.
Here we take a different approach. We simply use a 3rd possible value
for the "killed" variable so that all threads know they must break out
of the run-poll-loop and immediately stop.
This patch was tested by commenting the stream_shutdown() calls in
hard_stop() to increase the chances to see a stream use released
resources. With this fix applied, it never crashes anymore.
This fix should be backported to 1.9 and 1.8.
Many times we've been missing per-process traffic statistics. While it
didn't make sense in multi-process mode, with threads it does. Thus we
now have a counter of bytes emitted by raw_sock, and a freq counter for
these as well. However, freq_ctr are limited to 32 bits, and given that
loads of 300 Gbps have already been reached over a loopback using
splicing, we need to downscale this a bit. Here we're storing 1/32 of
the byte rate, which gives a theorical limit of 128 GB/s or ~1 Tbps,
which is more than enough. Let's have fun re-reading this sentence in
2029 :-) The values can be read in "show info" output on the CLI.
These commands don't follow the same flow as the rest of the commands,
each of them iterates over all header lines before switching to the
next directive. In addition they make no distinction between start
line and headers and can lead to unparsable rewrites which are very
difficult to deal with internally.
Most of them are still occasionally found in configurations, mainly
because of the usual "we've always done this way". By marking them
deprecated and emitting a warning and recommendation on first use of
each of them, we will raise users' awareness of users regarding the
cleaner, faster and more reliable alternatives.
Some use cases of "reqrep" still appear from time to time for URL
rewriting that is not so convenient with other rules. But at least
users facing this requirement will explain their use case so that we
can best serve them. Some discussion started on this subject in a
thread linked to from github issue #100.
The goal is to remove them in 2.1 since they require to reparse the
result before indexing it and we don't want this hack to live long.
The following directives were marked deprecated :
-reqadd
-reqallow
-reqdel
-reqdeny
-reqiallow
-reqidel
-reqideny
-reqipass
-reqirep
-reqitarpit
-reqpass
-reqrep
-reqtarpit
-rspadd
-rspdel
-rspdeny
-rspidel
-rspideny
-rspirep
-rsprep
We currently have the ability to register functions to be called early
on thread creation and at thread deinitialization. It turns out this is
not sufficient because certain such functions may use resources that are
being allocated by the other ones, thus creating a race condition depending
only on the linking order. For example the mworker needs to register a
file descriptor while the pollers will reallocate the fd_updt[] array.
Similarly logs and trashes may be used by some init functions while it's
unclear whether they have been deduplicated.
The same issue happens on deinit, if the fd_updt[] or trash is released
before some functions finish to use them, we'll get into trouble.
This patch creates a couple of early and late callbacks for per-thread
allocation/freeing of resources. A few init functions were moved there,
and the fd init code was split between the two (since it used to both
allocate and initialize at once). This way the init/deinit sequence is
expected to be safe now.
This patch should be backported to 1.9 as at least the trash/log issue
seems to be present. The run_thread_poll_loop() code is a bit different
there as the mworker is not a callback, but it will have no effect and
it's enough to drop the mworker changes.
This bug was reported by Ilya Shipitsin in github issue #104.
Event ports are kqueue/epoll polling class for Solaris. Code is based
on https://github.com/joyent/haproxy-1.8/tree/joyent/dev-v1.8.8.
Event ports are available only on SunOS systems derived from
Solaris 10 and later (including illumos systems).
It doesn't make sense to keep this struct thread_info in global.h, it
causes difficulties to access its contents from hathreads.h, let's move
it to the threads where it ought to have been created.
This is the per-thread CPU runtime clock, it will be used to measure
the CPU usage of each thread and by the lockup detection mechanism. It
must only be retrieved at the beginning of run_thread_poll_loop() since
the thread must already have been started for this. But it must be done
before performing any per-thread initcall so that all thread init
functions have access to the clock ID.
Note that it could make sense to always have this clockid available even
in non-threaded situations and place the process' clock there instead.
But it would add portability issues which are currently easy to deal
with by disabling threads so it may not be worth it for now.
This way we'll be able to store more per-thread information than just
the pthread pointer. The storage became an array of struct instead of
an allocated array since it's very small (typically 512 bytes) and not
worth the hassle of dealing with memory allocation on this. The array
was also renamed thread_info to make its intended usage more explicit.
Currently the thread array is a local variable inside a function block
and there is no access to it from outside, which often complicates
debugging. Let's make it global and export it. Also the allocation
return is now checked.
When we initially experimented with threads and processes support, we
needed to implement arrays of threads per process for cpu-map, but this
is not needed anymore since we support either threads or processes.
Let's simply make the thread-based cpu-map per thread and not per
thread and per process since that's not used anymore. Doing so reduces
the global struct from 33kB to 1.5kB.
As by default we add all keepalive connections to the idle pool, if we run
into a pathological case, where all client don't do keepalive, but the server
does, and haproxy is configured to only reuse "safe" connections, we will
soon find ourself having lots of idling, unusable for new sessions, connections,
while we won't have any file descriptors available to create new connections.
To fix this, add 2 new global settings, "pool_low_ratio" and "pool_high_ratio".
pool-low-fd-ratio is the % of fds we're allowed to use (against the maximum
number of fds available to haproxy) before we stop adding connections to the
idle pool, and destroy them instead. The default is 20. pool-high-fd-ratio is
the % of fds we're allowed to use (against the maximum number of fds available
to haproxy) before we start killing idling connection in the event we have to
create a new outgoing connection, and no reuse is possible. The default is 25.
It's always a pain to get a core dump when enabling user/group setting
(which disables the dumpable flag on Linux), when using a chroot and/or
when haproxy is started by a service management tool which requires
complex operations to just raise the core dump limit.
This patch introduces a new "set-dumpable" global directive to work
around these troubles by doing the following :
- remove file size limits (equivalent of ulimit -f unlimited)
- remove core size limits (equivalent of ulimit -c unlimited)
- mark the process dumpable again (equivalent of suid_dumpable=1)
Some of these will depend on the operating system. This way it becomes
much easier to retrieve a core file. Temporarily moving the chroot to
a user-writable place generally enough.
Since the introduction of the options field, we can use it to store the
type of process.
type = 'm' is replaced by PROC_O_TYPE_MASTER
type = 'w' is replaced by PROC_O_TYPE_WORKER
type = 'e' is replaced by PROC_O_TYPE_PROG
The old values are still used in the HAPROXY_PROCESSES environment
variable to pass the information during a reload.
This option is already the default, but its opposite 'no option
start-on-reload' allows the master to keep a previous instance of a
program and don't start a new one upon a reload.
The old program will then appear as a current one in "show proc" and
could also trigger an exit-on-failure upon a segfault.
Previously we were assuming than a process was in a leaving state when
its number of reload was greater than 0. With mworker programs it's not
the case anymore so we need to store a leaving state.
This patch implements the external binary support in the master worker.
To configure an external process, you need to use the program section,
for example:
program dataplane-api
command ./dataplane_api
Those processes are launched at the same time as the workers.
During a reload of HAProxy, those processes are dealing with the same
sequence as a worker:
- the master is re-executed
- the master sends a USR1 signal to the program
- the master launches a new instance of the program
During a stop, or restart, a SIGTERM is sent to the program.
Let's keep a copy of these initial values. They will be useful to
compute automatic maxconn, as well as to restore proper limits when
doing an execve() on external checks.
tune.listener.multi-queue { on | off }
Enables ('on') or disables ('off') the listener's multi-queue accept which
spreads the incoming traffic to all threads a "bind" line is allowed to run
on instead of taking them for itself. This provides a smoother traffic
distribution and scales much better, especially in environments where threads
may be unevenly loaded due to external activity (network interrupts colliding
with one thread for example). This option is enabled by default, but it may
be forcefully disabled for troubleshooting or for situations where it is
estimated that the operating system already provides a good enough
distribution and connections are extremely short-lived.
For some embedded systems, it's pointless to have 32- or even 64- large
arrays of processes when it's known that much fewer processes will be
used in the worst case. Let's introduce this MAX_PROCS define which
contains the highest number of processes allowed to run at once. It
still defaults to LONGBITS but may be lowered.
These two functions return either all_{proc,threads}_mask, or the argument.
This is used to default to all_proc_mask or all_threads_mask when not set
on bind_conf or proxies.
Most calls to hap_register_post_check(), hap_register_post_deinit(),
hap_register_per_thread_init(), hap_register_per_thread_deinit() can
be done using initcalls and will not require a constructor anymore.
Let's create a set of simplified macros for this, called respectively
REGISTER_POST_CHECK, REGISTER_POST_DEINIT, REGISTER_PER_THREAD_INIT,
and REGISTER_PER_THREAD_DEINIT.
Some files were not modified because they wouldn't benefit from this
or because they conditionally register (e.g. the pollers).
