7955 Commits

Author SHA1 Message Date
Willy Tarreau
21b069dca8 MINOR: server: create new function cli_find_server() to find a server
Several CLI commands require a server, so let's have a function to
look this one up and prepare the appropriate error message and the
appctx's state in case of failure.
2016-11-24 16:59:27 +01:00
Willy Tarreau
de57a578ba MINOR: cli: create new function cli_has_level() to validate permissions
This function is used to check that the CLI features the appropriate
level of permissions or to prepare the adequate error message.
2016-11-24 16:59:27 +01:00
William Lallemand
69e9644e35 REORG: cli: move show stat resolvers to dns.c
Move dns CLI functions to dns.c and use the cli keyword API to register
actions on the CLI.
2016-11-24 16:59:27 +01:00
William Lallemand
ad8be61c7e REORG: cli: move map and acl code to map.c
Move map and acl CLI functions to map.c and use the cli keyword API to
register actions on the CLI. Then remove the now unused individual
"add" and "del" keywords.
2016-11-24 16:59:27 +01:00
William Lallemand
32af203b75 REORG: cli: move ssl CLI functions to ssl_sock.c
Move ssl CLI functions to ssl_sock.c and use the cli keyword API to
register ssl actions on the CLI.
2016-11-24 16:59:27 +01:00
William Lallemand
9ed6203aef REORG: cli: split dumpstats.h in stats.h and cli.h
proto/dumpstats.h has been split in 4 files:

  * proto/cli.h  contains protypes for the CLI
  * proto/stats.h contains prototypes for the stats
  * types/cli.h contains definition for the CLI
  * types/stats.h contains definition for the stats
2016-11-24 16:59:27 +01:00
William Lallemand
74c24fb071 REORG: cli: split dumpstats.c in src/cli.c and src/stats.c
dumpstats.c was containing either the stats code and the CLI code.
The cli code has been moved to cli.c and the stats code to stats.c
2016-11-24 16:59:27 +01:00
Willy Tarreau
8e0bb0ae16 MINOR: connection: add names for transport and data layers
This makes debugging easier and avoids having to put ugly checks
against certain well-known internal struct pointers.
2016-11-24 16:58:12 +01:00
Willy Tarreau
2dc770c641 MINOR: connection: add a few functions to report the data and xprt layers' names
These functions will be needed by "show sess" on the CLI, let's make them
globally available. It's important to note that due to the fact that we
still do not set the data and transport layers' names in the structures,
we still have to rely on some exports just to match the pointers. This is
ugly but is preferable to adding many includes since the short-term goal
is to get rid of these tests by having proper names in place.
2016-11-24 16:49:40 +01:00
David Carlier
327298c215 BUILD: fix build on Solaris 10/11
uint16_t instead of u_int16_t
None ISO fields of struct tm are not present, but
by zeroyfing it, on GNU and BSD systems tm_gmtoff
field will be set.

[wt: moved the memset into each of the date functions]
2016-11-22 12:04:19 +01:00
Christopher Faulet
a00d817aba MINOR: filters: Add check_timeouts callback to handle timers expiration on streams
A filter can now be notified when a stream is woken up because of an expired
timer.

The documentation and the TRACE filter have been updated.
2016-11-21 15:29:58 +01:00
Willy Tarreau
733b1327a6 DEBUG: connection: mark the closed FDs with a value that is easier to detect
Setting an FD to -1 when closed isn't the most easily noticeable thing
to do when we're chasing accidental reuse of a stale file descriptor.
Instead set it to that large a negative value that it will overflow the
fdtab and provide an analysable core at the moment the issue happens.
Care was taken to ensure it doesn't overflow nor change sign on 32-bit
machines when multiplied by fdtab, and that it also remains negative for
the various checks that exist. The value equals 0xFDDEADFD which happens
to be easily spotted in a debugger.
2016-11-18 15:00:42 +01:00
Willy Tarreau
350135cf49 BUG/MEDIUM: connection: check the control layer before stopping polling
The bug described in commit 568743a ("BUG/MEDIUM: stream-int: completely
detach connection on connect error") was not a stream-interface layer bug
but a connection layer bug. There was exactly one place in the code where
we could change a file descriptor's status without first checking whether
it is valid or not, it was in conn_stop_polling(). This one is called when
the polling status is changed after an update, and calls fd_stop_both even
if we had already closed the file descriptor :

1479388298.484240 ->->->->->   conn_fd_handler > conn_cond_update_polling
1479388298.484240 ->->->->->->   conn_cond_update_polling > conn_stop_polling
1479388298.484241 ->->->->->->->   conn_stop_polling > conn_ctrl_ready
1479388298.484241                  conn_stop_polling < conn_ctrl_ready
1479388298.484241 ->->->->->->->   conn_stop_polling > fd_stop_both
1479388298.484242 ->->->->->->->->   fd_stop_both > fd_update_cache
1479388298.484242 ->->->->->->->->->   fd_update_cache > fd_release_cache_entry
1479388298.484242                      fd_update_cache < fd_release_cache_entry
1479388298.484243                    fd_stop_both < fd_update_cache
1479388298.484243                  conn_stop_polling < fd_stop_both
1479388298.484243                conn_cond_update_polling < conn_stop_polling
1479388298.484243              conn_fd_handler < conn_cond_update_polling

The problem with the previous fix above is that it break the http_proxy mode
and possibly even some Lua parts and peers to a certain extent ; all outgoing
connections where the target address is initially copied into the outgoing
connection which experience a retry would use a random outgoing address after
the retry because closing and detaching the connection causes the target
address to be lost. This was attempted to be addressed by commit 0857d7a
("BUG/MAJOR: stream: properly mark the server address as unset on connect
retry") but it used to only solve the most visible effect and not the root
cause.

Prior to this fix, it was possible to cause this config to keep CLOSE_WAIT
for as long as it takes to expire a client or server timeout (note the
missing client timeout) :

   listen test
        mode http
        bind :8002
        server s1 127.0.0.1:8001

   $ tcploop 8001 L0 W N20 A R P100 S:"HTTP/1.1 200 OK\r\nContent-length: 0\r\n\r\n" &
   $ tcploop 8002 N200 C T W S:"GET / HTTP/1.0\r\n\r\n" O P10000 K

With this patch, these CLOSE_WAIT properly vanish when both processes leave.

This commit reverts the two fixes above and replaces them with the proper
fix in connection.h. It must be backported to 1.6 and 1.5. Thanks to
Robson Roberto Souza Peixoto for providing very detailed traces showing
some obvious inconsistencies leading to finding this bug.
2016-11-18 14:48:52 +01:00
Thierry FOURNIER / OZON.IO
a44fdd95f9 MEDIUM: lua: Add cli handler for Lua
Now, HAProxy allows to register some keys in the "cli". This patch allows
to handle these keys with Lua code.
2016-11-18 14:32:03 +01:00
Thierry FOURNIER / OZON.IO
6a22dcbe27 MINOR: cli: add private pointer and release function
This pointer will be used for storing private context. With this,
the same executed function can handle more than one keyword. This
will be very useful for creation Lua cli bindings.

The release function is called when the command is terminated (give
back the hand to the prompt) or when the session is broken (timeout
or client closed).
2016-11-18 14:32:03 +01:00
Thierry FOURNIER / OZON.IO
62fec75183 MINOR: lua: add ip addresses and network manipulation function
Add two functions core.parse_addr() and core.match_addr() where are used
for matching networks.
2016-11-12 10:42:30 +01:00
Willy Tarreau
f07741d0d5 BUILD: http: include types/sample.h in proto_http.h
Commit d7c9196 ("MAJOR: filters: Add filters support") removed sample.h
from proto_http.h, but it has become necessary as of commit fd7edd3
("MINOR: Move http method enum from proto_http to sample") in order
to have HTTP_METH_*. Due to this, the "debug/flags" utility doesn't
build anymore.
2016-11-11 07:56:48 +01:00
Christopher Faulet
ba7bc164f7 MINOR: spoe/checks: Add support for SPOP health checks
A new "option spop-check" statement has been added to enable server health
checks based on SPOP HELLO handshake. SPOP is the protocol used by SPOE filters
to talk to servers.
2016-11-09 22:57:02 +01:00
Christopher Faulet
f7e4e7e096 MAJOR: spoe: Add an experimental Stream Processing Offload Engine
SPOE makes possible the communication with external components to retrieve some
info using an in-house binary protocol, the Stream Processing Offload Protocol
(SPOP). In the long term, its aim is to allow any kind of offloading on the
streams. This first version, besides being experimental, won't do lot of
things. The most important today is to validate the protocol design and lay the
foundations of what will, one day, be a full offload engine for the stream
processing.

So, for now, the SPOE can offload the stream processing before "tcp-request
content", "tcp-response content", "http-request" and "http-response" rules. And
it only supports variables creation/suppression. But, in spite of these limited
features, we can easily imagine to implement a SSO solution, an ip reputation
service or an ip geolocation service.

Internally, the SPOE is implemented as a filter. So, to use it, you must use
following line in a proxy proxy section:

  frontend my-front
      ...
      filter spoe [engine <name>] config <file>
      ...

It uses its own configuration file to keep the HAProxy configuration clean. It
is also a easy way to disable it by commenting out the filter line.

See "doc/SPOE.txt" for all details about the SPOE configuration.
2016-11-09 22:57:01 +01:00
Christopher Faulet
85d79c94a9 MINOR: vars: Add 'unset-var' action/converter
It does the opposite of 'set-var' action/converter. It is really useful for
per-process variables. But, it can be used for any scope.

The lua function 'unset_var' has also been added.
2016-11-09 22:57:01 +01:00
Christopher Faulet
ff2613ed7a MEDIUM: vars: Add a per-process scope for variables
Now it is possible to use variables attached to a process. The scope name is
'proc'. These variables are released only when HAProxy is stopped.

'tune.vars.proc-max-size' directive has been added to confiure the maximum
amount of memory used by "proc" variables. And because memory accounting is
hierachical for variables, memory for "proc" vars includes memory for "sess"
vars.
2016-11-09 22:57:00 +01:00
Christopher Faulet
09c9df286b MINOR: vars: Add vars_set_by_name_ifexist function
This function, unsurprisingly, sets a variable value only if it already
exists. In other words, this function will succeed only if the variable was
found somewhere in the configuration during HAProxy startup.

It will be used by SPOE filter. So an agent will be able to set a value only for
existing variables. This prevents an agent to create a very large number of
unused variables to flood HAProxy and exhaust the memory reserved to variables..
2016-11-09 22:57:00 +01:00
Christopher Faulet
476e5d0e03 REORG: sample: move code to release a sample expression in sample.c
This code has been moved from haproxy.c to sample.c and the function
release_sample_expr can now be called from anywhere to release a sample
expression. This function will be used by the stream processing offload engine
(SPOE).
2016-11-09 22:57:00 +01:00
Christopher Faulet
79bdef3cad MINOR: cfgparse: Parse scope lines and save the last one parsed
A scope is a section name between square bracket, alone on its line, ie:

  [scope-name]
  ...

The spaces at the beginning and at the end of the line are skipped. Comments at
the end of the line are also skipped.

When a scope is parsed, its name is saved in the global variable
cfg_scope. Initially, cfg_scope is NULL and it remains NULL until a valid scope
line is parsed.

This feature remains unused in the HAProxy configuration file and
undocumented. However, it will be used during SPOE configuration parsing.
2016-11-09 22:56:59 +01:00
Christopher Faulet
7110b40d06 MINOR: cfgparse: Add functions to backup and restore registered sections
This feature will be used by the stream processing offload engine (SPOE) to
parse dedicated configuration files without mixing HAProxy sections with SPOE
sections.

So, here we can back up all sections known by HAProxy, unregister all of them
and add new ones, dedicted to the SPOE. Once the SPOE configuration file parsed,
we can roll back all changes by restoring HAProxy sections.
2016-11-09 22:56:59 +01:00
Christopher Faulet
31ed32dce4 MEDIUM: filters: Add attch/detach and stream_set_backend callbacks
New callbacks have been added to handle creation and destruction of filter
instances:

* 'attach' callback is called after a filter instance creation, when it is
  attached to a stream. This happens when the stream is started for filters
  defined on the stream's frontend and when the backend is set for filters
  declared on the stream's backend. It is possible to ignore the filter, if
  needed, by returning 0. This could be useful to have conditional filtering.

* 'detach' callback is called when a filter instance is detached from a stream,
  before its destruction. This happens when the stream is stopped for filters
  defined on the stream's frontend and when the analyze ends for filters defined
  on the stream's backend.

In addition, the callback 'stream_set_backend' has been added to know when a
backend is set for a stream. It is only called when the frontend and the backend
are not the same. And it is called for all filters attached to a stream
(frontend and backend).

Finally, the TRACE filter has been updated.
2016-11-09 22:50:54 +01:00
Christopher Faulet
898566e7e6 CLEANUP: remove last references to 'ruleset' section 2016-11-09 22:50:54 +01:00
Willy Tarreau
3eed10e54b MINOR: init: add -dr to ignore server address resolution failures
It is very common when validating a configuration out of production not to
have access to the same resolvers and to fail on server address resolution,
making it difficult to test a configuration. This option simply appends the
"none" method to the list of address resolution methods for all servers,
ensuring that even if the libc fails to resolve an address, the startup
sequence is not interrupted.
2016-11-09 15:33:52 +01:00
Willy Tarreau
4310d36a7e MINOR: server: add support for explicit numeric address in init-addr
This will allow a server to automatically fall back to an explicit numeric
IP address when all other methods fail. The address is simply specified in
the address list.
2016-11-09 15:30:47 +01:00
Willy Tarreau
25e515235a MEDIUM: server: make use of init-addr
It is now supported. If not set, we default to the legacy methods list
which is "last,libc".
2016-11-09 15:30:47 +01:00
Baptiste Assmann
25938278b7 MEDIUM: server: add a new init-addr server line setting
This new setting supports a comma-delimited list of methods used to
resolve the server's FQDN to an IP address. Currently supported methods
are "libc" (use the regular libc's resolver) and "last" (use the last
known valid address found in the state file).

The list is implemented in a 32-bit integer, because each init-addr
method only requires 3 bits. The last one must always be SRV_IADDR_END
(0), allowing to store up to 10 methods in a single 32 bit integer.

Note: the doc is provided at the end of this series.
2016-11-09 15:30:47 +01:00
Baptiste Assmann
987e16d6f4 MINOR: dns: implement extra 'hold' timers.
This adds new "hold" timers : nx, refused, timeout, other. This timers
will be used to tell HAProxy to keep an erroneous response as valid for
the corresponding period. For now they're only configured, not enforced.
2016-11-09 15:30:47 +01:00
Willy Tarreau
8b42848a44 MINOR: server: make srv_set_admin_state() capable of telling why this happens
It will be important to help debugging some DNS resolution issues to
know why a server was marked down, so let's make  the function support
a 3rd argument with an indication of the reason. Passing NULL will keep
the message as-is.
2016-11-09 15:30:47 +01:00
Baptiste Assmann
89aa7f30da MINOR: new srv_admin flag: SRV_ADMF_RMAINT
This flag has to be set when an IP address resolution fails (either
using libc at start up or using HAProxy's runtime resolver). This will
automatically trigger the administrative status "MAINT", through the
global mask SRV_ADMF_MAINT.
2016-11-09 15:23:16 +01:00
Baptiste Assmann
83cbaa531f MAJOR: server: postpone address resolution
Server addresses are not resolved anymore upon the first pass so that we
don't fail if an address cannot be resolved by the libc. Instead they are
processed all at once after the configuration is fully loaded, by the new
function srv_init_addr(). This function only acts on the server's address
if this address uses an FQDN, which appears in server->hostname.

For now the function does two things, to followup with HAProxy's historical
default behavior:

  1. apply server IP address found in server-state file if runtime DNS
     resolution is enabled for this server

  2. use the DNS resolver provided by the libc

If none of the 2 options above can find an IP address, then an error is
returned.

All of this will be needed to support the new server parameter "init-addr".
For now, the biggest user-visible change is that all server resolution errors
are dumped at once instead of causing a startup failure one by one.
2016-11-09 14:24:20 +01:00
Dirkjan Bussink
1866d6d8f1 MEDIUM: ssl: Add support for OpenSSL 1.1.0
In the last release a lot of the structures have become opaque for an
end user. This means the code using these needs to be changed to use the
proper functions to interact with these structures instead of trying to
manipulate them directly.

This does not fix any deprecations yet that are part of 1.1.0, it only
ensures that it can be compiled against that version and is still
compatible with older ones.

[wt: openssl-0.9.8 doesn't build with it, there are conflicts on certain
     function prototypes which we declare as inline here and which are
     defined differently there. But openssl-0.9.8 is not supported anymore
     so probably it's OK to go without it for now and we'll see later if
     some users still need it. Emeric has reviewed this change and didn't
     spot anything obvious which requires special care. Let's try it for
     real now]
2016-11-08 20:54:41 +01:00
Willy Tarreau
e5d3169e1c CLEANUP: wurfl: reduce exposure in the rest of the code
The only reason wurfl/wurfl.h was needed outside of wurfl.c was to expose
wurfl_handle which is a pointer to a structure, referenced by global.h.
By just storing a void* there instead, we can confine all wurfl code to
wurfl.c, which is really nice.
2016-11-08 18:47:25 +01:00
scientiamobile
d0027ed5b1 MEDIUM: wurfl: add Scientiamobile WURFL device detection module
WURFL is a high-performance and low-memory footprint mobile device
detection software component that can quickly and accurately detect
over 500 capabilities of visiting devices. It can differentiate between
portable mobile devices, desktop devices, SmartTVs and any other types
of devices on which a web browser can be installed.

In order to add WURFL device detection support, you would need to
download Scientiamobile InFuze C API and install it on your system.
Refer to www.scientiamobile.com to obtain a valid InFuze license.

Any useful information on how to configure HAProxy working with WURFL
may be found in:

  doc/WURFL-device-detection.txt
  doc/configuration.txt
  examples/wurfl-example.cfg

Please find more information about WURFL device detection API detection
at https://docs.scientiamobile.com/documentation/infuze/infuze-c-api-user-guide
2016-11-08 14:21:43 +01:00
Willy Tarreau
757478e900 BUG/MEDIUM: servers: properly propagate the maintenance states during startup
Right now there is an issue with the way the maintenance flags are
propagated upon startup. They are not propagate, just copied from the
tracked server. This implies that depending on the server's order, some
tracking servers may not be marked down. For example this configuration
does not work as expected :

        server s1 1.1.1.1:8000 track s2
        server s2 1.1.1.1:8000 track s3
        server s3 1.1.1.1:8000 track s4
        server s4 wtap:8000 check inter 1s disabled

It results in s1/s2 being up, and s3/s4 being down, while all of them
should be down.

The only clean way to process this is to run through all "root" servers
(those not tracking any other server), and to propagate their state down
to all their trackers. This is the same algorithm used to propagate the
state changes. It has to be done both to compute the IDRAIN flag and the
IMAINT flag. However, doing so requires that tracking servers are not
marked as inherited maintenance anymore while parsing the configuration
(and given that it is wrong, better drop it).

This fix also addresses another side effect of the bug above which is
that the IDRAIN/IMAINT flags are stored in the state files, and if
restored while the tracked server doesn't have the equivalent flag,
the servers may end up in a situation where it's impossible to remove
these flags. For example in the configuration above, after removing
"disabled" on server s4, the other servers would have remained down,
and not anymore with this fix. Similarly, the combination of IMAINT
or IDRAIN with their respective forced modes was not accepted on
reload, which is wrong as well.

This bug has been present at least since 1.5, maybe even 1.4 (it came
with tracking support). The fix needs to be backported there, though
the srv-state parts are irrelevant.

This commit relies on previous patch to silence warnings on startup.
2016-11-07 14:31:52 +01:00
Willy Tarreau
2235b261b6 OPTIM: http: move all http character classs tables into a single one
We used to have 7 different character classes, each was 256 bytes long,
resulting in almost 2kB being used in the L1 cache. It's as cheap to
test a bit than to check the byte is not null, so let's store a 7-bit
composite value and check for the respective bits there instead.

The executable is now 4 kB smaller and the performance on small
objects increased by about 1% to 222k requests/second with a config
involving 4 http-request rules including 1 header lookup, one header
replacement, and 2 variable assignments.
2016-11-05 15:58:08 +01:00
Willy Tarreau
9df94c2b25 MINOR: peers: remove the pointer to the stream
There's no reason to use the stream anymore, only the appctx should be
used by a peer. This was a leftover from the migration to appctx and it
caused some confusion, so let's totally drop it now. Note that half of
the patch are just comment updates.
2016-10-31 20:07:01 +01:00
Andrew Rodland
13d5ebb913 MINOR: server: compute a "cumulative weight" to allow chash balancing to hit its target
For active servers, this is the sum of the eweights of all active
servers before this one in the backend, and
[srv->cumulative_weight .. srv_cumulative_weight + srv_eweight) is a
space occupied by this server in the range [0 .. lbprm.tot_wact), and
likewise for backup servers with tot_wbck. This allows choosing a
server or a range of servers proportional to their weight, by simple
integer comparison.

Signed-off-by: Andrew Rodland <andrewr@vimeo.com>
2016-10-25 20:21:32 +02:00
Andrew Rodland
b1f48e3161 MINOR: backend: add hash-balance-factor option for hash-type consistent
0 will mean no balancing occurs; otherwise it represents the ratio
between the highest-loaded server and the average load, times 100 (i.e.
a value of 150 means a 1.5x ratio), assuming equal weights.

Signed-off-by: Andrew Rodland <andrewr@vimeo.com>
2016-10-25 20:21:32 +02:00
Andrew Rodland
e168feb4a8 MINOR: proxy: add 'served' field to proxy, equal to total of all servers'
This will allow lb_chash to determine the total active sessions for a
proxy without any computation.

Signed-off-by: Andrew Rodland <andrewr@vimeo.com>
2016-10-25 20:21:32 +02:00
Willy Tarreau
a5bc36b31c MINOR: stats: emit dses
This is the number of denied sessions, blocked by "tcp-request session reject".
2016-10-21 18:19:48 +02:00
Willy Tarreau
620408f406 MEDIUM: tcp: add registration and processing of TCP L5 rules
This commit introduces "tcp-request session" rules. These are very
much like "tcp-request connection" rules except that they're processed
after the handshake, so it is possible to consider SSL information and
addresses rewritten by the proxy protocol header in actions. This is
particularly useful to track proxied sources as this was not possible
before, given that tcp-request content rules are processed after each
HTTP request. Similarly it is possible to assign the proxied source
address or the client's cert to a variable.
2016-10-21 18:19:24 +02:00
Willy Tarreau
27df66e8d9 MINOR: counters: add new fields for denied_sess
This will be used with denied sessions. This counter is not exposed yet.
2016-10-21 18:19:24 +02:00
Willy Tarreau
7d9736fb5d CLEANUP: tcp rules: mention everywhere that tcp-conn rules are L4
This is in order to make integration of tcp-request-session cleaner :
- tcp_exec_req_rules() was renamed tcp_exec_l4_rules()
- LI_O_TCP_RULES was renamed LI_O_TCP_L4_RULES
  (LI_O_*'s horrible indent was also fixed and a provision was left
   for L5 rules).
2016-10-21 18:19:24 +02:00
Willy Tarreau
8a90b8ea19 MINOR: stats: output dcon
These are denied conns. Strangely this wasn't emitted while it used to be
available for a while. It corresponds to the number of connections blocked
by "tcp-request connection reject".
2016-10-21 18:17:56 +02:00
William Lallemand
1e08cd819a MEDIUM: cli: register CLI keywords with cli_register_kw()
To register a new cli keyword, you need to declare a cli_kw_list
structure in your source file:

	static struct cli_kw_list cli_kws = {{ },{
		{ { "test", "list", NULL }, "test list : do some tests on the cli", test_parsing, NULL },
		{ { NULL }, NULL, NULL, NULL, NULL }
	}};

And then register it:

	cli_register_kw(&cli_kws);

The first field is an array of 5 elements, where you declare the
keywords combination which will match, it must be ended by a NULL
element.

The second field is used as a usage message, it will appear in the help
of the cli, you can set it to NULL if you don't want to show it, it's a
good idea if you want to overwrite some existing keywords.

The two last fields are callbacks.

The first one is used at parsing time, you can use it to parse the
arguments of your keywords and print small messages. The function must
return 1 in case of a failure, otherwise 0:

	#include <proto/dumpstats.h>

	static int test_parsing(char **args, struct appctx *appctx)
	{
		struct chunk out;

		if (!*args[2]) {
			appctx->ctx.cli.msg = "Error: the 3rd argument is mandatory !";
			appctx->st0 = STAT_CLI_PRINT;
			return 1;
		}
		chunk_reset(&trash);
		chunk_printf(&trash, "arg[3]: %s\n", args[2]);
		chunk_init(&out, NULL, 0);
		chunk_dup(&out, &trash);
		appctx->ctx.cli.err = out.str;
		appctx->st0 = STAT_CLI_PRINT_FREE; /* print and free in the default cli_io_handler */
		return 0;
	}

The last field is the IO handler callback, it can be set to NULL if you
want to use the default cli_io_handler() otherwise you can write your
own. You can use the private pointer in the appctx if you need to store
a context or some data. stats_dump_sess_to_buffer() is a good example of
IO handler, IO handlers often use the appctx->st2 variable for the state
machine. The handler must return 0 in case it have to be recall later
otherwise 1.
2016-10-19 19:03:40 +02:00