When an abstract unix socket is bound by HAProxy (using "abns@" prefix),
NUL bytes are appended at the end of its path until sun_path is filled
(for a total of 108 characters).
Here we add an alternative to pass only the non-NUL length of that path
to connect/bind calls, such that the effective path of the socket's name
is as humanly written. This may be useful to interconnect with existing
softwares that implement abstract sockets with this logic instead of the
default haproxy one.
This is achieved by implementing the "abnsz" socket prefix (instead of
"abns"), which stands for "zero-terminated ABNS". "abnsz" prefix may be
used anywhere "abns" is. Internally, haproxy uses the custom socket
family (AF_CUST_ABNS vs AF_CUST_ABNSZ) to differentiate default abns
sockets from zero-terminated ones.
Documentation was updated and regtest was added.
Fixes GH issues #977 and #2479
Co-authored-by: Aurelien DARRAGON <adarragon@haproxy.com>
Thanks to previous commit, we may now use dedicated addrcmp functions for
each UNIX address family. This allows to simplify sock_unix_addrcmp()
function and avoid useless checks in order to try to guess the socket
type.
In this patch we implement sock_abns_addrcmp() and sock_abnsz_addrcmp()
functions, which are respectively used for ABNS and ABNSZ custom families
sock_unix_addrcmp() now only holds regular UNIX socket comparing logic.
As in previous commit, let's push the logic a bit further in order to
properly restore the effective UNIX socket type when leveraging
get_src() and get_dst() sock functions, since they rely on getpeername()
and getsockname() under the hood, both of which will actually loose the
effective family and return AF_UNIX for all our custom UNIX sockets.
To do this, add sock_restore_unix_family() helper function from the logic
implemented in the previous commit, and call this function from get_src()
and get_dst() in case of unix socket prior to returning.
When getting sockets from older process in sock_get_old_sockets(), we
leverage getsockname() to fill sockaddr struct from known fd.
However, the kernel doesn't know about our custom UNIX families such
as CUST_ABNS and CUST_ABNSZ which are both based on AF_UNIX real family.
Since haproxy socket API relies on effective family (and not real family)
to recognize the socket type instead of having to guess it by analyzing
the path content, let's restore it right after getsockname() since we
have all the infos needed to deduce the right family.
If the path starts with a NULL byte, we know that it is an abstract sock.
Then we simply check <addrlen> value from getsockname() to know if the
addr makes uses of the whole path space (normal ABNS) or partial path
space (zero ABNS / aka ABNZ) terminated by 0.
For now it's the same as abns. We'll need to modify sock_unix_addrcmp(),
and a few other ones to support effective path length when dealing with
the \0. Let's check with Tristan's patch for this (upcoming patch).
Co-authored-by: Aurelien DARRAGON <adarragon@haproxy.com>
Following previous commit, in str2sa_range(), make use of address' family
which was just set to check if the socket is ABNS or not instead of
relying on an extra boolean to save this info.
Now that we can easily distinguish regular UNIX socket from ABNS sockets
by simply looking at the address family, stop looking at the first byte
from addr->sun_path to guess if the socket is an ABNS one or not. Looking
at the family is straightforward and will allow to differentiate between
upcoming ABNSZ and ABNS (where looking at the first byte from path won't
help anymore).
This is a pre-requisite to adding the abnsz socket address family:
in this patch we make use of protocol API rework started by 732913f
("MINOR: protocol: properly assign the sock_domain and sock_family") in
order to implement a dedicated address family for ABNS sockets (based on
UNIX parent family).
Thanks to this, it will become trivial to implement a new ABNSZ (for abns
zero) family which is essentially the same as ABNS but with a slight
difference when it comes to path handling (ABNS uses the whole sun_path
length, while ABNSZ's path is zero terminated and evaluation stops at 0)
It was verified that this patch doesn't break reg-tests and behaves
properly (tests performed on the CLI with show sess and show fd).
Anywhere relevant, AF_CUST_ABNS is handled alongside AF_UNIX. If no
distinction needs to be made, real_family() is used to fetch the proper
real family type to handle it properly.
Both stream and dgram were converted, so no functional change should be
expected for this "internal" rework, except that proto will be displayed
as "abns_{stream,dgram}" instead of "unix_{stream,dgram}".
Before ("show sess" output):
0x64c35528aab0: proto=unix_stream src=unix:1 fe=GLOBAL be=<NONE> srv=<none> ts=00 epoch=0 age=0s calls=1 rate=0 cpu=0 lat=0 rq[f=848000h,i=0,an=00h,ax=] rp[f=80008000h,i=0,an=00h,ax=] scf=[8,0h,fd=21,rex=10s,wex=] scb=[8,1h,fd=-1,rex=,wex=] exp=10s rc=0 c_exp=
After:
0x619da7ad74c0: proto=abns_stream src=unix:1 fe=GLOBAL be=<NONE> srv=<none> ts=00 epoch=0 age=0s calls=1 rate=0 cpu=0 lat=0 rq[f=848000h,i=0,an=00h,ax=] rp[f=80008000h,i=0,an=00h,ax=] scf=[8,0h,fd=22,rex=10s,wex=] scb=[8,1h,fd=-1,rex=,wex=] exp=10s rc=0 c_exp=
Co-authored-by: Aurelien DARRAGON <adarragon@haproxy.com>
When using trace with -dt, the trace_parse_cmd() function is doing a
strtok which write \0 into the argv string.
When using the mworker mode, and reloading, argv was modified and the
trace won't work anymore because the first : is replaced by a '\0'.
This patch fixes the issue by allocating a temporary string so we don't
modify the source string directly. It also replace strtok by its
reentrant version strtok_r.
Must be backported as far as 2.9.
These is a collection of functions I'm occasionally using to navigate
in core dumps. Only working ones were extracted.
Those requiring knowledge of global variables (e.g. pools, proxy list)
use the one extracted from the post_mortem struct. That one is defined
in post-mortem.gdb and needs to be initialized using "pm_init post_mortem"
or "pm_init <pointer>". From this point a number of global variables are
accessible even if symbols are missing; those ones are then used by other
functions to dump streams, threads, pools, proxies etc.
The files can be sourced or copy-pasted into a gdb session. It's worth
trying to keep them up-to-date, as the old ones used to navigate through
tasks are no longer usable due to massive changes.
That one is huge and unneeded since we now have the pointer to the
whole thread_info[] array, which does contain the freshest version
of these info and many more. Let's just get rid of it entirely.
These are the notes of a day long code analysis session (CFA+WTA)
aimed at figuring what's missing during most code troubleshooting
sessions. The goal is to provide good indications about what rules/
filters were still active when the processing ended (timeout, error
etc), what subscribers are still active (indicating waiting for an
event), and what shut/abort events were met at the various levels
of each side's stack, in each direction.
Thanks to previous commit, we can now use strnlen2() function to perform
strnlen() portable equivalent instead of re-implementing the logic under
_lf_text_len() function.
strnlen2() is functionally equivalent to strnlen(). Goal is to provide
an alternative to strnlen() which is not portable since it requires
_POSIX_C_SOURCE >= 200809L
During re-execution master keeps always opened "reload" sockpair FDs and
shared sockpair ipc_fd[0], the latter is using to transfert listeners sockets
from the previously forked worker to the new one. So, these master's FDs are
inherited in the newly forked worker and must be closed in its context.
"reload" sockpair inherited FDs and shared sockpair FD (ipc_fd[0]) are closed
separately, becase master doesn't recreate "reload" sockpair each time after
its re-exec. It always keeps the same FDs for this "reload" sockpair. So in
worker context it can be closed immediately after the fork.
At contrast, shared sockpair is created each time after reload, when the new
worker will be forked. So, if N previous workers are still exist at this moment,
the new worker will inherit N ipc_fd[0] from master. So, it's more save to
close all these FDs after get_listeners_fd() and bind_listeners() calls.
Otherwise, early closed FDs in the worker context will be immediately bound to
listeners and we could potentially have some bugs.
Using nested 'if' operator, while checking if we will need to allocate again the
"reload" sockpair, does not degrade performance, as mworker_create_master_cli is
a startup routine.
This nested 'if' (we check one condition in each operator) makes more visible the
fact, that the "reload" sockpair is allocated only once, when the master process
starts and it does not re-allocated again (hence, its FDs are not closed) during
reloads. This way of checking multiple conditions here makes more easy to spot
this fact, while analysing the code in order to investigate FD leaks between
master and worker.
The pointer to struct global is also an important element to have in
post_mortem given that it's used a lot to take decisions in the code.
Let's just add it. It's worth noting that we could get rid of argc/argv
at this point since they're also present in the global struct, but they
don't cost much there anyway.
When using 'debug dev fd', the output of laddr and raddr can contain
some garbage.
This patch replaces any control or non-printable character by a '.'.
Historically for size limitation reasons, we would only dump the
backtrace of stuck threads. The problem is that when triggering
a panic or other reasons, we have no backtrace, which effectively
limits it to the watchdog timer. It's also visible in "show threads"
which used to report backtraces for all threads in 2.4 and displays
none nowadays, making its use much more limited.
A first approach could be to just dump the thread that triggers the
panic (in addition to stuck threads). But that remains quite limited
since "show threads" would still display nothing. This patch takes a
better approach consisting in dumping all non-idle threads. This way
the output is less polluted that with the older approach (no need to
dump all those waiting in the poller), and all active threads are
visible, in panics as well as in "show threads". As such, the CLI
command "debug dev panic" now dmups backtraces again. This is already
a benefit which will ease testing of various locations against the
ability to resolve useful symbols.
Dealing with a core and a stripped executable is a pain when it comes
to finding pools, proxies or thread contexts. Let's put a pointer to
these heads and arrays in the post_mortem struct for easier location.
Other critical lists like this could possibly benefit from being added
later.
Here we now have:
- tgroup_info
- thread_info
- tgroup_ctx
- thread_ctx
- pools
- proxies
Example:
$ objdump -h haproxy|grep post
34 _post_mortem 000014b0 0000000000cfd400 0000000000cfd400 008fc400 2**8
(gdb) set $pm=(struct post_mortem*)0x0000000000cfd400
(gdb) p $pm->tgroup_ctx[0]
$8 = {
threads_harmless = 254,
threads_idle = 254,
stopping_threads = 0,
timers = {
b = {0x0, 0x0}
},
niced_tasks = 0,
__pad = 0xf5662c <ha_tgroup_ctx+44> "",
__end = 0xf56640 <ha_tgroup_ctx+64> ""
}
(gdb) info thr
Id Target Id Frame
* 1 Thread 0x7f9e7706a440 (LWP 21169) 0x00007f9e76a9c868 in raise () from /lib64/libc.so.6
2 Thread 0x7f9e76a60640 (LWP 21175) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
3 Thread 0x7f9e7613d640 (LWP 21176) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
4 Thread 0x7f9e7493a640 (LWP 21179) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
5 Thread 0x7f9e7593c640 (LWP 21177) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
6 Thread 0x7f9e7513b640 (LWP 21178) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
7 Thread 0x7f9e6ffff640 (LWP 21180) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
8 Thread 0x7f9e6f7fe640 (LWP 21181) 0x00007f9e76b343c7 in wait4 () from /lib64/libc.so.6
(gdb) p/x $pm->thread_info[0].pth_id
$12 = 0x7f9e7706a440
(gdb) p/x $pm->thread_info[1].pth_id
$13 = 0x7f9e76a60640
(gdb) set $px = *$pm->proxies
while ($px != 0)
printf "%#lx %s served=%u\n", $px, $px->id, $px->served
set $px = ($px)->next
end
0x125eda0 GLOBAL served=0
0x12645b0 stats served=0
0x1266940 comp served=0
0x1268e10 comp_bck served=0
0x1260cf0 <OCSP-UPDATE> served=0
0x12714c0 <HTTPCLIENT> served=0
Placing it in its own section will ease its finding, particularly in
gdb which is too dumb to find anything in memory. Now it will be
sufficient to issue this:
$ gdb -ex "info files" -ex "quit" ./haproxy core 2>/dev/null |grep _post_mortem
0x0000000000cfd300 - 0x0000000000cfe780 is _post_mortem
or this:
$ objdump -h haproxy|grep post
34 _post_mortem 00001480 0000000000cfd300 0000000000cfd300 008fc300 2**8
to spot the symbol's address. Then it can be read this way:
(gdb) p *(struct post_mortem *)0x0000000000cfd300
In order to ease finding of the post_mortem struct in core dumps, let's
make it start with a recognizable pattern of exactly 32 chars (to
preserve alignment):
"POST-MORTEM STARTS HERE+7654321\0"
It can then be found like this from gdb:
(gdb) find 0x000000012345678, 0x0000000100000000, 'P','O','S','T','-','M','O','R','T','E','M'
0xcfd300 <post_mortem>
1 pattern found.
Or easier with any other more practical tool (who as ever used "find" in
gdb, given that it cannot iterate over maps and is 100% useless?).
During 11th and 12th iteration of the development cycle for the H2 auto
rx window, several approaches were attempted to figure if another buffer
could be allocated or not. One of them consisted in looping back to the
beginning of the function requesting a new buffer slot and getting one
if the buffer was either apparently or confirmed full. The latest one
consisted in directly allocating the next buffer from the two places
where it's found to be proven full, instead of checking with the now
defunct h2s_may_get_rxbuf() if we were allowed to get once an loop.
That approach was retained. In this case the "full" variabled is no
longer needed, so let's get rid of it because the construct looks bogus
and confuses coverity (and possibly code readers as the intent is unclear
compared to the code).
Commit 091de0f9b2 ("MINOR: debug: slightly change the thread_dump_pointer
signification") caused the following warning to be emitted when threads
are disabled:
src/debug.c: In function 'ha_thread_dump_one':
src/debug.c:359:9: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
Let's just disguise the pointer to silence it. It should be backported
where the patch above was backported, since it was part of a series aiming
at making thread dumps more exploitable from core dumps.
There is no reason to disable the 0-copy data forwarding if an end-of-stream
was reported on the consumer side. Indeed, the consumer will send data in
this case. So there is no reason to check the read side here.
This patch may be backported as far as 2.9.
When the response forwarding is aborted, we must not report a client abort
if a EOS was seen on client side. On abort performed by the stream must be
considered.
This bug was introduced when the SHUTR was splitted in 2 flags.
This patch must be backported as far as 2.8.
When some data must be sent to the endpoint but an error was previously
reported, nothing is performed and we leave. But, in this case, the SC is not
notified the sends are blocked.
It is indeed an issue if the endpoint reports an error after consuming all
data from the SC. In the endpoint the outgoing data are trashed because of
the error, but on the SC, everything was sent, even if an error was also
reported.
Because of this bug, it is possible to have outgoing data blocked at the SC
level but without any write timeout armed. In some cases, this may lead to
blocking conditions where the stream is never closed.
So now, when outgoing data cannot be sent because an previous error was
triggered, a blocked send is reported. This way, it is possible to report a
write timeout.
This patch should fix the issue #2754. It must be backported as far as 2.8.
Each server is inserted in a global list named servers_list on
new_server(). This list is then only used to finalize servers
initialization after parsing.
On dynamic server creation, there is no issue as new_server() is under
thread isolation. However, when a server is deleted after its refcount
reached zero, srv_drop() removes it from servers_list without lock
protection. In the longterm, this can cause list corruption and crashes,
especially if multiple adjacent servers are removed in parallel.
To fix this, convert servers_list to a mt_list. This should not impact
performance as servers_list is not used during runtime outside of server
creation/deletion.
This should fix github issue #2733. Thanks to Chris Staite who first
found the issue here.
This must be backported up to 2.6.
If a dynamic server is added with check or agent-check, its refcount is
incremented after server keyword parsing. However, if add server fails
at a later stage, refcount is only decremented once, which prevented the
server to be fully released.
This causes a leak with a server which is detached from most of the
lists but still exits in the system.
This bug is considered minor as only a few conditions may cause a
failure in add server after check/agent-check initialization. This is
the case if there is a naming collision or the dynamic ID cannot be
generated.
To fix this, simply decrement server refcount on add server error path
if either check and/or agent-check are flagged as activated.
This bug is related to github issue #2733. Thanks to Chris Staite who
first found the leak.
This must be backported up to 2.6.
There are two parts in mworker_cli_proxy_create(): allocating and setting up
MASTER proxy and allocating and setting up servers on ipc_fd[0] of the
sockpairs shared with workers.
So, let's split mworker_cli_proxy_create() into two functions respectively.
Each of them takes **errmsg as an argument to write an error message, which may
be triggered by some subcalls. The content of this errmsg will allow to extend
the final alert message shown to user, if these new functions will fail.
The main goals of this split is to allow to move these two parts independantly
in future and makes the code of haproxy initialization in haproxy.c more
transparent.
Before refactoring master-worker architecture, resources to setup master CLI
for the new worker process (shared sockpair, entry in proc_list) were created
in init() before parsing the configuration and binding listening sockets. So,
master during its re-exec has had to cleanup the new worker's ressources in
a case, when it fails at some initialization step before the fork.
Now fork happens very early and worker parses its configuration by itself. If
it fails during the initialization stage, all clean ups (deleting the fds of
the shared sockpair, proc_list cleanup) are performed in SIGCHLD handler up to
catching the SIGCHLD corresponded to this new worker. So, there is no longer
need to call mworker_cleanup_proc() in mworker_reexec().
As for mworker_cleanlisteners(), there is no longer need to call this function.
Master parses now only "global" and "program" sections, so it allocates only
MASTER proxy, which is stopped in mworker_reexec() by mworker_cli_proxy_stop().
Let's keep the definitions of mworker_cleanlisteners() and
mworker_cleanup_proc() in mworker.c for the moment. We may reuse parts of its
code later.
As master-worker fork happens now at early init stage and worker then parses
its configuration and performs all initialization steps, let's duplicate
startup logs ring for it, just before the moment when it enters in its pollong
loop. Startup logs ring content is shown as an output of the "reload" master
CLI command and we should be able to dump here worker initialization logs.
Log messages are written in startup logs ring only, when mode MODE_STARTING is
set (see print_message()). So, to be able to keep in startup logs the last
worker alerts, let's withdraw MODE_STARTING and let's reset user messages
context respectively just before entering in polling loop.
This fix does not need to be backported as it is a part of previous patches
from this version, which refactor master-worker architecture.
This patch simplifies the code of startup_logs_init_shm(). We no longer re-exec
master process twice after each reload to free its unused memory, which it had
to allocate, because it has parsed all configuration sections. So, there is no
longer need to keep SHM fd opened between the first and the next reloads. We
can completely remove HAPROXY_STARTUPLOGS_FD.
In step_init_1() we continue to call startup_logs_init_shm() to open SHM and to
allocate startup logs ring area within it. In master-worker mode, worker
duplicates initial startup logs ring after sending its READY state to master.
Sharing the same ring between two processes until the worker finishes its
initialization allows to show at master CLI output worker's startup logs.
During the next reload master process should free the memory allocated for the
ring structure. Then after the execvp() it will reopen and map SHM area again
and it will reallocate again the ring structure.
After sending its "READY" status worker should not keep the access
to MASTER proxy, thus, it shouldn't be able to send any other commands further
to master process.
To achieve this, let's stop in master context master CLI listener attached on
the sockpair shared with worker. We do this just after receiving the worker's
status message.
When master enters in recovery mode after unsuccessfull reload
HAPROXY_LOAD_SUCCESS should be set as 0. Like this
cli_io_handler_show_cli_sock() could dump in master CLI its warnings and alerts,
saved in startup logs ring.
No need to backport this fix, as this is related to the previous patches in
this version to refactor master-worker architecture.
On systems where many libs are loaded, it's hard to track suspected
leaks. Having a per-DSO summary makes it more convenient. That's what
we're doing here by summarizing all calls per DSO before showing the
total.
The previous commit contains a bug in some COUNT_IF() relying on the pipe
inside the IOBUF. We must take care to have a pipe before checking its size.
No backport needed.
Debug counters were added on all connection error when pending data remain
blocked in the input or ouput buffers. The same is performed when the H1C is
released, when the connection is closed and when a timeout is reached. Idea
is to be able to count all cases where data are lost, especially the
outgoing ones.
gcc-4.8 is unhappy with the cfg_file initialization:
src/flt_spoe.c: In function 'parse_spoe_flt':
src/flt_spoe.c:2202:9: warning: missing braces around initializer [-Wmissing-braces]
struct cfgfile cfg_file = {0};
^
src/flt_spoe.c:2202:9: warning: (near initialization for 'cfg_file.list') [-Wmissing-braces]
This is due to the embedded list member. Initializing it to empty like
we do almost everywhere else makes it happy. No backport is needed as
this was changed in 3.1-dev5 only.
As described in GH #2765, there were situations where http connections
would be re-used for requests to different endpoints, which is obviously
unexpected. In GH #2765, this occured with httpclient and UNIX socket
combination, but later code analysis revealed that while disabling http
reuse on httpclient proxy helped, it didn't fix the underlying issue since
it was found that conn_calculate_hash_sockaddr() didn't take into account
families such as AF_UNIX or AF_CUST_SOCKPAIR, and because of that the
sock_addr part of the connection wasn't hashed.
To properly fix the issue, let's explicly handle UNIX (both regular and
ABNS) and AF_CUST_SOCKPAIR families, so that the destination address is
properly hashed. To prevent this bug from re-appearing: when the family
isn't known, instead of doing nothing like before, let's fall back to a
generic (unoptimal) hashing which hashes the whole sockaddr_storage struct
As a workaround, http-reuse may be disabled on impacted proxies.
(unfortunately this doesn't help for httpclient since reuse policy
defaults to safe and cannot be modified from the config)
It should be backported to all stable versions.
Shout out to @christopherhibbert for having reported the issue and
provided a trivial reproducer.
[ada: prior to 3.0, ctx adjt is required because conn_hash_update()'s
prototype is slightly different]
Sometimes it would be desirable to include some debugging output only
under certain conditions, but the end of the transfer is too late to
apply some rules.
Here we take the approach of making a converter ("when") that takes a
condition among an arbitrary list, and decides whether or not to let
the input sample pass through or not based on the condition. This
allows for example to log debugging information only when an error
was encountered during the processing (sort of an extension of
dontlog-normal). The conditions are quite limited (stopping, error,
normal, toapplet, forwarded, processed) and can be negated. The
converter can also be chained to use more complex conditions.
A suggested example will be:
# log "dbg={-}" when fine, or "dbg={... debug info ...}" on error:
log-format "$HAPROXY_HTTP_LOG_FMT dbg={%[bs.debug_str,when(!normal)]}"
The idea here is to record how many times a filter is being called on a
stream. We're incrementing the same counter all along, regardless of the
type of event, since the purpose is essentially to detect one that might
be misbehaving. The number of calls is reported in "show sess all" next
to the filter name. It may also help detect suboptimal processing. For
example compressing 1GB shows 138k calls to the compression filter, which
is roughly two calls per buffer. Maybe we wake up with incomplete buffers
and compress less. That's left for a future analysis.
