2 Unix SMB/CIFS implementation.
3 Samba internal messaging functions
4 Copyright (C) Andrew Tridgell 2000
5 Copyright (C) 2001 by Martin Pool
6 Copyright (C) 2002 by Jeremy Allison
7 Copyright (C) 2007 by Volker Lendecke
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 @defgroup messages Internal messaging framework
28 @brief Module for internal messaging between Samba daemons.
30 The idea is that if a part of Samba wants to do communication with
31 another Samba process then it will do a message_register() of a
32 dispatch function, and use message_send_pid() to send messages to
35 The dispatch function is given the pid of the sender, and it can
36 use that to reply by message_send_pid(). See ping_message() for a
39 @caution Dispatch functions must be able to cope with incoming
40 messages on an *odd* byte boundary.
42 This system doesn't have any inherent size limitations but is not
43 very efficient for large messages or when messages are sent in very
49 #include "dbwrap/dbwrap.h"
52 #include "lib/util/tevent_unix.h"
53 #include "lib/background.h"
55 struct messaging_callback
{
56 struct messaging_callback
*prev
, *next
;
58 void (*fn
)(struct messaging_context
*msg
, void *private_data
,
60 struct server_id server_id
, DATA_BLOB
*data
);
64 /****************************************************************************
65 A useful function for testing the message system.
66 ****************************************************************************/
68 static void ping_message(struct messaging_context
*msg_ctx
,
74 const char *msg
= "none";
77 if (data
->data
!= NULL
) {
78 free_me
= talloc_strndup(talloc_tos(), (char *)data
->data
,
82 DEBUG(1,("INFO: Received PING message from PID %s [%s]\n",
83 procid_str_static(&src
), msg
));
85 messaging_send(msg_ctx
, src
, MSG_PONG
, data
);
88 /****************************************************************************
89 Register/replace a dispatch function for a particular message type.
90 JRA changed Dec 13 2006. Only one message handler now permitted per type.
91 *NOTE*: Dispatch functions must be able to cope with incoming
92 messages on an *odd* byte boundary.
93 ****************************************************************************/
96 struct messaging_context
*msg_ctx
;
104 /****************************************************************************
105 Send one of the messages for the broadcast.
106 ****************************************************************************/
108 static int traverse_fn(struct db_record
*rec
, const struct server_id
*id
,
109 uint32_t msg_flags
, void *state
)
111 struct msg_all
*msg_all
= (struct msg_all
*)state
;
114 /* Don't send if the receiver hasn't registered an interest. */
116 if((msg_flags
& msg_all
->msg_flag
) == 0) {
120 /* If the msg send fails because the pid was not found (i.e. smbd died),
121 * the msg has already been deleted from the messages.tdb.*/
123 status
= messaging_send_buf(msg_all
->msg_ctx
, *id
, msg_all
->msg_type
,
124 (const uint8_t *)msg_all
->buf
, msg_all
->len
);
126 if (NT_STATUS_EQUAL(status
, NT_STATUS_INVALID_HANDLE
)) {
129 * If the pid was not found delete the entry from
133 DEBUG(2, ("pid %s doesn't exist\n", procid_str_static(id
)));
135 dbwrap_record_delete(rec
);
142 * Send a message to all smbd processes.
144 * It isn't very efficient, but should be OK for the sorts of
145 * applications that use it. When we need efficient broadcast we can add
148 * @param n_sent Set to the number of messages sent. This should be
149 * equal to the number of processes, but be careful for races.
151 * @retval True for success.
153 bool message_send_all(struct messaging_context
*msg_ctx
,
155 const void *buf
, size_t len
,
158 struct msg_all msg_all
;
160 msg_all
.msg_type
= msg_type
;
161 if (msg_type
< 0x100) {
162 msg_all
.msg_flag
= FLAG_MSG_GENERAL
;
163 } else if (msg_type
> 0x100 && msg_type
< 0x200) {
164 msg_all
.msg_flag
= FLAG_MSG_NMBD
;
165 } else if (msg_type
> 0x200 && msg_type
< 0x300) {
166 msg_all
.msg_flag
= FLAG_MSG_PRINT_GENERAL
;
167 } else if (msg_type
> 0x300 && msg_type
< 0x400) {
168 msg_all
.msg_flag
= FLAG_MSG_SMBD
;
169 } else if (msg_type
> 0x400 && msg_type
< 0x600) {
170 msg_all
.msg_flag
= FLAG_MSG_WINBIND
;
171 } else if (msg_type
> 4000 && msg_type
< 5000) {
172 msg_all
.msg_flag
= FLAG_MSG_DBWRAP
;
180 msg_all
.msg_ctx
= msg_ctx
;
182 serverid_traverse(traverse_fn
, &msg_all
);
184 *n_sent
= msg_all
.n_sent
;
188 struct messaging_context
*messaging_init(TALLOC_CTX
*mem_ctx
,
189 struct tevent_context
*ev
)
191 struct messaging_context
*ctx
;
194 if (!(ctx
= talloc_zero(mem_ctx
, struct messaging_context
))) {
198 ctx
->id
= procid_self();
201 status
= messaging_dgm_init(ctx
, ctx
, &ctx
->local
);
203 if (!NT_STATUS_IS_OK(status
)) {
204 DEBUG(2, ("messaging_dgm_init failed: %s\n",
210 if (lp_clustering()) {
211 status
= messaging_ctdbd_init(ctx
, ctx
, &ctx
->remote
);
213 if (!NT_STATUS_IS_OK(status
)) {
214 DEBUG(2, ("messaging_ctdbd_init failed: %s\n",
220 ctx
->id
.vnn
= get_my_vnn();
222 messaging_register(ctx
, NULL
, MSG_PING
, ping_message
);
224 /* Register some debugging related messages */
226 register_msg_pool_usage(ctx
);
227 register_dmalloc_msgs(ctx
);
228 debug_register_msgs(ctx
);
233 struct server_id
messaging_server_id(const struct messaging_context
*msg_ctx
)
239 * re-init after a fork
241 NTSTATUS
messaging_reinit(struct messaging_context
*msg_ctx
)
245 TALLOC_FREE(msg_ctx
->local
);
247 msg_ctx
->id
= procid_self();
249 status
= messaging_dgm_init(msg_ctx
, msg_ctx
, &msg_ctx
->local
);
250 if (!NT_STATUS_IS_OK(status
)) {
251 DEBUG(0, ("messaging_dgm_init failed: %s\n",
256 TALLOC_FREE(msg_ctx
->remote
);
258 if (lp_clustering()) {
259 status
= messaging_ctdbd_init(msg_ctx
, msg_ctx
,
262 if (!NT_STATUS_IS_OK(status
)) {
263 DEBUG(1, ("messaging_ctdbd_init failed: %s\n",
274 * Register a dispatch function for a particular message type. Allow multiple
277 NTSTATUS
messaging_register(struct messaging_context
*msg_ctx
,
280 void (*fn
)(struct messaging_context
*msg
,
283 struct server_id server_id
,
286 struct messaging_callback
*cb
;
288 DEBUG(5, ("Registering messaging pointer for type %u - "
290 (unsigned)msg_type
, private_data
));
293 * Only one callback per type
296 for (cb
= msg_ctx
->callbacks
; cb
!= NULL
; cb
= cb
->next
) {
297 /* we allow a second registration of the same message
298 type if it has a different private pointer. This is
299 needed in, for example, the internal notify code,
300 which creates a new notify context for each tree
301 connect, and expects to receive messages to each of
303 if (cb
->msg_type
== msg_type
&& private_data
== cb
->private_data
) {
304 DEBUG(5,("Overriding messaging pointer for type %u - private_data=%p\n",
305 (unsigned)msg_type
, private_data
));
307 cb
->private_data
= private_data
;
312 if (!(cb
= talloc(msg_ctx
, struct messaging_callback
))) {
313 return NT_STATUS_NO_MEMORY
;
316 cb
->msg_type
= msg_type
;
318 cb
->private_data
= private_data
;
320 DLIST_ADD(msg_ctx
->callbacks
, cb
);
325 De-register the function for a particular message type.
327 void messaging_deregister(struct messaging_context
*ctx
, uint32_t msg_type
,
330 struct messaging_callback
*cb
, *next
;
332 for (cb
= ctx
->callbacks
; cb
; cb
= next
) {
334 if ((cb
->msg_type
== msg_type
)
335 && (cb
->private_data
== private_data
)) {
336 DEBUG(5,("Deregistering messaging pointer for type %u - private_data=%p\n",
337 (unsigned)msg_type
, private_data
));
338 DLIST_REMOVE(ctx
->callbacks
, cb
);
344 static bool messaging_is_self_send(const struct messaging_context
*msg_ctx
,
345 const struct server_id
*dst
)
347 return ((msg_ctx
->id
.vnn
== dst
->vnn
) &&
348 (msg_ctx
->id
.pid
== dst
->pid
));
352 Send a message to a particular server
354 NTSTATUS
messaging_send(struct messaging_context
*msg_ctx
,
355 struct server_id server
, uint32_t msg_type
,
356 const DATA_BLOB
*data
)
358 if (server_id_is_disconnected(&server
)) {
359 return NT_STATUS_INVALID_PARAMETER_MIX
;
362 if (!procid_is_local(&server
)) {
363 return msg_ctx
->remote
->send_fn(msg_ctx
, server
,
368 if (messaging_is_self_send(msg_ctx
, &server
)) {
369 struct messaging_rec rec
;
370 rec
.msg_version
= MESSAGE_VERSION
;
371 rec
.msg_type
= msg_type
& MSG_TYPE_MASK
;
373 rec
.src
= msg_ctx
->id
;
375 messaging_dispatch_rec(msg_ctx
, &rec
);
379 return msg_ctx
->local
->send_fn(msg_ctx
, server
, msg_type
, data
,
383 NTSTATUS
messaging_send_buf(struct messaging_context
*msg_ctx
,
384 struct server_id server
, uint32_t msg_type
,
385 const uint8_t *buf
, size_t len
)
387 DATA_BLOB blob
= data_blob_const(buf
, len
);
388 return messaging_send(msg_ctx
, server
, msg_type
, &blob
);
391 NTSTATUS
messaging_send_iov(struct messaging_context
*msg_ctx
,
392 struct server_id server
, uint32_t msg_type
,
393 const struct iovec
*iov
, int iovlen
)
398 buf
= iov_buf(talloc_tos(), iov
, iovlen
);
400 return NT_STATUS_NO_MEMORY
;
403 status
= messaging_send_buf(msg_ctx
, server
, msg_type
,
404 buf
, talloc_get_size(buf
));
410 static struct messaging_rec
*messaging_rec_dup(TALLOC_CTX
*mem_ctx
,
411 struct messaging_rec
*rec
)
413 struct messaging_rec
*result
;
415 result
= talloc_pooled_object(mem_ctx
, struct messaging_rec
,
417 if (result
== NULL
) {
422 /* Doesn't fail, see talloc_pooled_object */
424 result
->buf
.data
= talloc_memdup(result
, rec
->buf
.data
,
429 struct messaging_filtered_read_state
{
430 struct tevent_context
*ev
;
431 struct messaging_context
*msg_ctx
;
434 bool (*filter
)(struct messaging_rec
*rec
, void *private_data
);
437 struct messaging_rec
*rec
;
440 static void messaging_filtered_read_cleanup(struct tevent_req
*req
,
441 enum tevent_req_state req_state
);
443 struct tevent_req
*messaging_filtered_read_send(
444 TALLOC_CTX
*mem_ctx
, struct tevent_context
*ev
,
445 struct messaging_context
*msg_ctx
,
446 bool (*filter
)(struct messaging_rec
*rec
, void *private_data
),
449 struct tevent_req
*req
;
450 struct messaging_filtered_read_state
*state
;
451 size_t new_waiters_len
;
453 req
= tevent_req_create(mem_ctx
, &state
,
454 struct messaging_filtered_read_state
);
459 state
->msg_ctx
= msg_ctx
;
460 state
->filter
= filter
;
461 state
->private_data
= private_data
;
464 * We have to defer the callback here, as we might be called from
465 * within a different tevent_context than state->ev
467 tevent_req_defer_callback(req
, state
->ev
);
469 state
->tevent_handle
= messaging_dgm_register_tevent_context(
471 if (tevent_req_nomem(state
, req
)) {
472 return tevent_req_post(req
, ev
);
476 * We add ourselves to the "new_waiters" array, not the "waiters"
477 * array. If we are called from within messaging_read_done,
478 * messaging_dispatch_rec will be in an active for-loop on
479 * "waiters". We must be careful not to mess with this array, because
480 * it could mean that a single event is being delivered twice.
483 new_waiters_len
= talloc_array_length(msg_ctx
->new_waiters
);
485 if (new_waiters_len
== msg_ctx
->num_new_waiters
) {
486 struct tevent_req
**tmp
;
488 tmp
= talloc_realloc(msg_ctx
, msg_ctx
->new_waiters
,
489 struct tevent_req
*, new_waiters_len
+1);
490 if (tevent_req_nomem(tmp
, req
)) {
491 return tevent_req_post(req
, ev
);
493 msg_ctx
->new_waiters
= tmp
;
496 msg_ctx
->new_waiters
[msg_ctx
->num_new_waiters
] = req
;
497 msg_ctx
->num_new_waiters
+= 1;
498 tevent_req_set_cleanup_fn(req
, messaging_filtered_read_cleanup
);
503 static void messaging_filtered_read_cleanup(struct tevent_req
*req
,
504 enum tevent_req_state req_state
)
506 struct messaging_filtered_read_state
*state
= tevent_req_data(
507 req
, struct messaging_filtered_read_state
);
508 struct messaging_context
*msg_ctx
= state
->msg_ctx
;
511 tevent_req_set_cleanup_fn(req
, NULL
);
513 TALLOC_FREE(state
->tevent_handle
);
516 * Just set the [new_]waiters entry to NULL, be careful not to mess
517 * with the other "waiters" array contents. We are often called from
518 * within "messaging_dispatch_rec", which loops over
519 * "waiters". Messing with the "waiters" array will mess up that
523 for (i
=0; i
<msg_ctx
->num_waiters
; i
++) {
524 if (msg_ctx
->waiters
[i
] == req
) {
525 msg_ctx
->waiters
[i
] = NULL
;
530 for (i
=0; i
<msg_ctx
->num_new_waiters
; i
++) {
531 if (msg_ctx
->new_waiters
[i
] == req
) {
532 msg_ctx
->new_waiters
[i
] = NULL
;
538 static void messaging_filtered_read_done(struct tevent_req
*req
,
539 struct messaging_rec
*rec
)
541 struct messaging_filtered_read_state
*state
= tevent_req_data(
542 req
, struct messaging_filtered_read_state
);
544 state
->rec
= messaging_rec_dup(state
, rec
);
545 if (tevent_req_nomem(state
->rec
, req
)) {
548 tevent_req_done(req
);
551 int messaging_filtered_read_recv(struct tevent_req
*req
, TALLOC_CTX
*mem_ctx
,
552 struct messaging_rec
**presult
)
554 struct messaging_filtered_read_state
*state
= tevent_req_data(
555 req
, struct messaging_filtered_read_state
);
558 if (tevent_req_is_unix_error(req
, &err
)) {
559 tevent_req_received(req
);
562 *presult
= talloc_move(mem_ctx
, &state
->rec
);
566 struct messaging_read_state
{
568 struct messaging_rec
*rec
;
571 static bool messaging_read_filter(struct messaging_rec
*rec
,
573 static void messaging_read_done(struct tevent_req
*subreq
);
575 struct tevent_req
*messaging_read_send(TALLOC_CTX
*mem_ctx
,
576 struct tevent_context
*ev
,
577 struct messaging_context
*msg
,
580 struct tevent_req
*req
, *subreq
;
581 struct messaging_read_state
*state
;
583 req
= tevent_req_create(mem_ctx
, &state
,
584 struct messaging_read_state
);
588 state
->msg_type
= msg_type
;
590 subreq
= messaging_filtered_read_send(state
, ev
, msg
,
591 messaging_read_filter
, state
);
592 if (tevent_req_nomem(subreq
, req
)) {
593 return tevent_req_post(req
, ev
);
595 tevent_req_set_callback(subreq
, messaging_read_done
, req
);
599 static bool messaging_read_filter(struct messaging_rec
*rec
,
602 struct messaging_read_state
*state
= talloc_get_type_abort(
603 private_data
, struct messaging_read_state
);
605 return rec
->msg_type
== state
->msg_type
;
608 static void messaging_read_done(struct tevent_req
*subreq
)
610 struct tevent_req
*req
= tevent_req_callback_data(
611 subreq
, struct tevent_req
);
612 struct messaging_read_state
*state
= tevent_req_data(
613 req
, struct messaging_read_state
);
616 ret
= messaging_filtered_read_recv(subreq
, state
, &state
->rec
);
618 if (tevent_req_error(req
, ret
)) {
621 tevent_req_done(req
);
624 int messaging_read_recv(struct tevent_req
*req
, TALLOC_CTX
*mem_ctx
,
625 struct messaging_rec
**presult
)
627 struct messaging_read_state
*state
= tevent_req_data(
628 req
, struct messaging_read_state
);
631 if (tevent_req_is_unix_error(req
, &err
)) {
634 if (presult
!= NULL
) {
635 *presult
= talloc_move(mem_ctx
, &state
->rec
);
640 static bool messaging_append_new_waiters(struct messaging_context
*msg_ctx
)
642 if (msg_ctx
->num_new_waiters
== 0) {
646 if (talloc_array_length(msg_ctx
->waiters
) <
647 (msg_ctx
->num_waiters
+ msg_ctx
->num_new_waiters
)) {
648 struct tevent_req
**tmp
;
649 tmp
= talloc_realloc(
650 msg_ctx
, msg_ctx
->waiters
, struct tevent_req
*,
651 msg_ctx
->num_waiters
+ msg_ctx
->num_new_waiters
);
653 DEBUG(1, ("%s: talloc failed\n", __func__
));
656 msg_ctx
->waiters
= tmp
;
659 memcpy(&msg_ctx
->waiters
[msg_ctx
->num_waiters
], msg_ctx
->new_waiters
,
660 sizeof(struct tevent_req
*) * msg_ctx
->num_new_waiters
);
662 msg_ctx
->num_waiters
+= msg_ctx
->num_new_waiters
;
663 msg_ctx
->num_new_waiters
= 0;
668 struct messaging_defer_callback_state
{
669 struct messaging_context
*msg_ctx
;
670 struct messaging_rec
*rec
;
671 void (*fn
)(struct messaging_context
*msg
, void *private_data
,
672 uint32_t msg_type
, struct server_id server_id
,
677 static void messaging_defer_callback_trigger(struct tevent_context
*ev
,
678 struct tevent_immediate
*im
,
681 static void messaging_defer_callback(
682 struct messaging_context
*msg_ctx
, struct messaging_rec
*rec
,
683 void (*fn
)(struct messaging_context
*msg
, void *private_data
,
684 uint32_t msg_type
, struct server_id server_id
,
688 struct messaging_defer_callback_state
*state
;
689 struct tevent_immediate
*im
;
691 state
= talloc(msg_ctx
, struct messaging_defer_callback_state
);
693 DEBUG(1, ("talloc failed\n"));
696 state
->msg_ctx
= msg_ctx
;
698 state
->private_data
= private_data
;
700 state
->rec
= messaging_rec_dup(state
, rec
);
701 if (state
->rec
== NULL
) {
702 DEBUG(1, ("talloc failed\n"));
707 im
= tevent_create_immediate(state
);
709 DEBUG(1, ("tevent_create_immediate failed\n"));
713 tevent_schedule_immediate(im
, msg_ctx
->event_ctx
,
714 messaging_defer_callback_trigger
, state
);
717 static void messaging_defer_callback_trigger(struct tevent_context
*ev
,
718 struct tevent_immediate
*im
,
721 struct messaging_defer_callback_state
*state
= talloc_get_type_abort(
722 private_data
, struct messaging_defer_callback_state
);
723 struct messaging_rec
*rec
= state
->rec
;
725 state
->fn(state
->msg_ctx
, state
->private_data
, rec
->msg_type
, rec
->src
,
731 Dispatch one messaging_rec
733 void messaging_dispatch_rec(struct messaging_context
*msg_ctx
,
734 struct messaging_rec
*rec
)
736 struct messaging_callback
*cb
, *next
;
739 for (cb
= msg_ctx
->callbacks
; cb
!= NULL
; cb
= next
) {
741 if (cb
->msg_type
!= rec
->msg_type
) {
745 if (messaging_is_self_send(msg_ctx
, &rec
->dest
)) {
747 * This is a self-send. We are called here from
748 * messaging_send(), and we don't want to directly
749 * recurse into the callback but go via a
752 messaging_defer_callback(msg_ctx
, rec
, cb
->fn
,
756 * This comes from a different process. we are called
757 * from the event loop, so we should call back
760 cb
->fn(msg_ctx
, cb
->private_data
, rec
->msg_type
,
761 rec
->src
, &rec
->buf
);
764 * we continue looking for matching messages after finding
765 * one. This matters for subsystems like the internal notify
766 * code which register more than one handler for the same
771 if (!messaging_append_new_waiters(msg_ctx
)) {
776 while (i
< msg_ctx
->num_waiters
) {
777 struct tevent_req
*req
;
778 struct messaging_filtered_read_state
*state
;
780 req
= msg_ctx
->waiters
[i
];
783 * This got cleaned up. In the meantime,
784 * move everything down one. We need
785 * to keep the order of waiters, as
786 * other code may depend on this.
788 if (i
< msg_ctx
->num_waiters
- 1) {
789 memmove(&msg_ctx
->waiters
[i
],
790 &msg_ctx
->waiters
[i
+1],
791 sizeof(struct tevent_req
*) *
792 (msg_ctx
->num_waiters
- i
- 1));
794 msg_ctx
->num_waiters
-= 1;
798 state
= tevent_req_data(
799 req
, struct messaging_filtered_read_state
);
800 if (state
->filter(rec
, state
->private_data
)) {
801 messaging_filtered_read_done(req
, rec
);
809 static int mess_parent_dgm_cleanup(void *private_data
);
810 static void mess_parent_dgm_cleanup_done(struct tevent_req
*req
);
812 bool messaging_parent_dgm_cleanup_init(struct messaging_context
*msg
)
814 struct tevent_req
*req
;
816 req
= background_job_send(
817 msg
, msg
->event_ctx
, msg
, NULL
, 0,
818 lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
820 mess_parent_dgm_cleanup
, msg
);
824 tevent_req_set_callback(req
, mess_parent_dgm_cleanup_done
, msg
);
828 static int mess_parent_dgm_cleanup(void *private_data
)
830 struct messaging_context
*msg_ctx
= talloc_get_type_abort(
831 private_data
, struct messaging_context
);
834 status
= messaging_dgm_wipe(msg_ctx
);
835 DEBUG(10, ("messaging_dgm_wipe returned %s\n", nt_errstr(status
)));
836 return lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
840 static void mess_parent_dgm_cleanup_done(struct tevent_req
*req
)
842 struct messaging_context
*msg
= tevent_req_callback_data(
843 req
, struct messaging_context
);
846 status
= background_job_recv(req
);
848 DEBUG(1, ("messaging dgm cleanup job ended with %s\n",
851 req
= background_job_send(
852 msg
, msg
->event_ctx
, msg
, NULL
, 0,
853 lp_parm_int(-1, "messaging", "messaging dgm cleanup interval",
855 mess_parent_dgm_cleanup
, msg
);
857 DEBUG(1, ("background_job_send failed\n"));
859 tevent_req_set_callback(req
, mess_parent_dgm_cleanup_done
, msg
);