2 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 * SPDX-License-Identifier: GPL-2.0-only
8 #include "lttng/action/action.h"
9 #include "lttng/trigger/trigger-internal.h"
12 #include <urcu/rculfhash.h>
14 #include <common/defaults.h>
15 #include <common/error.h>
16 #include <common/futex.h>
17 #include <common/unix.h>
18 #include <common/dynamic-buffer.h>
19 #include <common/hashtable/utils.h>
20 #include <common/sessiond-comm/sessiond-comm.h>
21 #include <common/macros.h>
22 #include <lttng/condition/condition.h>
23 #include <lttng/action/action-internal.h>
24 #include <lttng/action/list-internal.h>
25 #include <lttng/domain-internal.h>
26 #include <lttng/notification/notification-internal.h>
27 #include <lttng/condition/condition-internal.h>
28 #include <lttng/condition/buffer-usage-internal.h>
29 #include <lttng/condition/session-consumed-size-internal.h>
30 #include <lttng/condition/session-rotation-internal.h>
31 #include <lttng/condition/event-rule-matches-internal.h>
32 #include <lttng/domain-internal.h>
33 #include <lttng/notification/channel-internal.h>
34 #include <lttng/trigger/trigger-internal.h>
35 #include <lttng/event-rule/event-rule-internal.h>
43 #include "condition-internal.h"
44 #include "event-notifier-error-accounting.h"
45 #include "notification-thread.h"
46 #include "notification-thread-events.h"
47 #include "notification-thread-commands.h"
48 #include "lttng-sessiond.h"
51 #define CLIENT_POLL_EVENTS_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP)
52 #define CLIENT_POLL_EVENTS_IN_OUT (CLIENT_POLL_EVENTS_IN | LPOLLOUT)
54 /* The tracers currently limit the capture size to PIPE_BUF (4kb on linux). */
55 #define MAX_CAPTURE_SIZE (PIPE_BUF)
57 enum lttng_object_type
{
58 LTTNG_OBJECT_TYPE_UNKNOWN
,
59 LTTNG_OBJECT_TYPE_NONE
,
60 LTTNG_OBJECT_TYPE_CHANNEL
,
61 LTTNG_OBJECT_TYPE_SESSION
,
64 struct lttng_trigger_list_element
{
65 /* No ownership of the trigger object is assumed. */
66 struct lttng_trigger
*trigger
;
67 struct cds_list_head node
;
70 struct lttng_channel_trigger_list
{
71 struct channel_key channel_key
;
72 /* List of struct lttng_trigger_list_element. */
73 struct cds_list_head list
;
74 /* Node in the channel_triggers_ht */
75 struct cds_lfht_node channel_triggers_ht_node
;
76 /* call_rcu delayed reclaim. */
77 struct rcu_head rcu_node
;
81 * List of triggers applying to a given session.
84 * - lttng_session_trigger_list_create()
85 * - lttng_session_trigger_list_build()
86 * - lttng_session_trigger_list_destroy()
87 * - lttng_session_trigger_list_add()
89 struct lttng_session_trigger_list
{
91 * Not owned by this; points to the session_info structure's
94 const char *session_name
;
95 /* List of struct lttng_trigger_list_element. */
96 struct cds_list_head list
;
97 /* Node in the session_triggers_ht */
98 struct cds_lfht_node session_triggers_ht_node
;
100 * Weak reference to the notification system's session triggers
103 * The session trigger list structure structure is owned by
104 * the session's session_info.
106 * The session_info is kept alive the the channel_infos holding a
107 * reference to it (reference counting). When those channels are
108 * destroyed (at runtime or on teardown), the reference they hold
109 * to the session_info are released. On destruction of session_info,
110 * session_info_destroy() will remove the list of triggers applying
111 * to this session from the notification system's state.
113 * This implies that the session_triggers_ht must be destroyed
114 * after the channels.
116 struct cds_lfht
*session_triggers_ht
;
117 /* Used for delayed RCU reclaim. */
118 struct rcu_head rcu_node
;
121 struct lttng_trigger_ht_element
{
122 struct lttng_trigger
*trigger
;
123 struct cds_lfht_node node
;
124 struct cds_lfht_node node_by_name_uid
;
125 struct cds_list_head client_list_trigger_node
;
126 /* call_rcu delayed reclaim. */
127 struct rcu_head rcu_node
;
130 struct lttng_condition_list_element
{
131 struct lttng_condition
*condition
;
132 struct cds_list_head node
;
135 struct channel_state_sample
{
136 struct channel_key key
;
137 struct cds_lfht_node channel_state_ht_node
;
138 uint64_t highest_usage
;
139 uint64_t lowest_usage
;
140 uint64_t channel_total_consumed
;
141 /* call_rcu delayed reclaim. */
142 struct rcu_head rcu_node
;
145 static unsigned long hash_channel_key(struct channel_key
*key
);
146 static int evaluate_buffer_condition(const struct lttng_condition
*condition
,
147 struct lttng_evaluation
**evaluation
,
148 const struct notification_thread_state
*state
,
149 const struct channel_state_sample
*previous_sample
,
150 const struct channel_state_sample
*latest_sample
,
151 uint64_t previous_session_consumed_total
,
152 uint64_t latest_session_consumed_total
,
153 struct channel_info
*channel_info
);
155 int send_evaluation_to_clients(const struct lttng_trigger
*trigger
,
156 const struct lttng_evaluation
*evaluation
,
157 struct notification_client_list
*client_list
,
158 struct notification_thread_state
*state
,
159 uid_t channel_uid
, gid_t channel_gid
);
162 /* session_info API */
164 void session_info_destroy(void *_data
);
166 void session_info_get(struct session_info
*session_info
);
168 void session_info_put(struct session_info
*session_info
);
170 struct session_info
*session_info_create(const char *name
,
171 uid_t uid
, gid_t gid
,
172 struct lttng_session_trigger_list
*trigger_list
,
173 struct cds_lfht
*sessions_ht
);
175 void session_info_add_channel(struct session_info
*session_info
,
176 struct channel_info
*channel_info
);
178 void session_info_remove_channel(struct session_info
*session_info
,
179 struct channel_info
*channel_info
);
181 /* lttng_session_trigger_list API */
183 struct lttng_session_trigger_list
*lttng_session_trigger_list_create(
184 const char *session_name
,
185 struct cds_lfht
*session_triggers_ht
);
187 struct lttng_session_trigger_list
*lttng_session_trigger_list_build(
188 const struct notification_thread_state
*state
,
189 const char *session_name
);
191 void lttng_session_trigger_list_destroy(
192 struct lttng_session_trigger_list
*list
);
194 int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
195 struct lttng_trigger
*trigger
);
198 int client_handle_transmission_status(
199 struct notification_client
*client
,
200 enum client_transmission_status transmission_status
,
201 struct notification_thread_state
*state
);
204 int handle_one_event_notifier_notification(
205 struct notification_thread_state
*state
,
206 int pipe
, enum lttng_domain_type domain
);
209 void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
);
212 int match_client_socket(struct cds_lfht_node
*node
, const void *key
)
214 /* This double-cast is intended to supress pointer-to-cast warning. */
215 const int socket
= (int) (intptr_t) key
;
216 const struct notification_client
*client
= caa_container_of(node
,
217 struct notification_client
, client_socket_ht_node
);
219 return client
->socket
== socket
;
223 int match_client_id(struct cds_lfht_node
*node
, const void *key
)
225 /* This double-cast is intended to supress pointer-to-cast warning. */
226 const notification_client_id id
= *((notification_client_id
*) key
);
227 const struct notification_client
*client
= caa_container_of(
228 node
, struct notification_client
, client_id_ht_node
);
230 return client
->id
== id
;
234 int match_channel_trigger_list(struct cds_lfht_node
*node
, const void *key
)
236 struct channel_key
*channel_key
= (struct channel_key
*) key
;
237 struct lttng_channel_trigger_list
*trigger_list
;
239 trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
240 channel_triggers_ht_node
);
242 return !!((channel_key
->key
== trigger_list
->channel_key
.key
) &&
243 (channel_key
->domain
== trigger_list
->channel_key
.domain
));
247 int match_session_trigger_list(struct cds_lfht_node
*node
, const void *key
)
249 const char *session_name
= (const char *) key
;
250 struct lttng_session_trigger_list
*trigger_list
;
252 trigger_list
= caa_container_of(node
, struct lttng_session_trigger_list
,
253 session_triggers_ht_node
);
255 return !!(strcmp(trigger_list
->session_name
, session_name
) == 0);
259 int match_channel_state_sample(struct cds_lfht_node
*node
, const void *key
)
261 struct channel_key
*channel_key
= (struct channel_key
*) key
;
262 struct channel_state_sample
*sample
;
264 sample
= caa_container_of(node
, struct channel_state_sample
,
265 channel_state_ht_node
);
267 return !!((channel_key
->key
== sample
->key
.key
) &&
268 (channel_key
->domain
== sample
->key
.domain
));
272 int match_channel_info(struct cds_lfht_node
*node
, const void *key
)
274 struct channel_key
*channel_key
= (struct channel_key
*) key
;
275 struct channel_info
*channel_info
;
277 channel_info
= caa_container_of(node
, struct channel_info
,
280 return !!((channel_key
->key
== channel_info
->key
.key
) &&
281 (channel_key
->domain
== channel_info
->key
.domain
));
285 int match_trigger(struct cds_lfht_node
*node
, const void *key
)
287 struct lttng_trigger
*trigger_key
= (struct lttng_trigger
*) key
;
288 struct lttng_trigger_ht_element
*trigger_ht_element
;
290 trigger_ht_element
= caa_container_of(node
, struct lttng_trigger_ht_element
,
293 return !!lttng_trigger_is_equal(trigger_key
, trigger_ht_element
->trigger
);
297 int match_trigger_token(struct cds_lfht_node
*node
, const void *key
)
299 const uint64_t *_key
= key
;
300 struct notification_trigger_tokens_ht_element
*element
;
302 element
= caa_container_of(node
,
303 struct notification_trigger_tokens_ht_element
, node
);
304 return *_key
== element
->token
;
308 int match_client_list_condition(struct cds_lfht_node
*node
, const void *key
)
310 struct lttng_condition
*condition_key
= (struct lttng_condition
*) key
;
311 struct notification_client_list
*client_list
;
312 const struct lttng_condition
*condition
;
314 assert(condition_key
);
316 client_list
= caa_container_of(node
, struct notification_client_list
,
317 notification_trigger_clients_ht_node
);
318 condition
= client_list
->condition
;
320 return !!lttng_condition_is_equal(condition_key
, condition
);
324 int match_session(struct cds_lfht_node
*node
, const void *key
)
326 const char *name
= key
;
327 struct session_info
*session_info
= caa_container_of(
328 node
, struct session_info
, sessions_ht_node
);
330 return !strcmp(session_info
->name
, name
);
334 const char *notification_command_type_str(
335 enum notification_thread_command_type type
)
338 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
339 return "REGISTER_TRIGGER";
340 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
341 return "UNREGISTER_TRIGGER";
342 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
343 return "ADD_CHANNEL";
344 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
345 return "REMOVE_CHANNEL";
346 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
347 return "SESSION_ROTATION_ONGOING";
348 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
349 return "SESSION_ROTATION_COMPLETED";
350 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
351 return "ADD_TRACER_EVENT_SOURCE";
352 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
353 return "REMOVE_TRACER_EVENT_SOURCE";
354 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
355 return "LIST_TRIGGERS";
356 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
357 return "GET_TRIGGER";
358 case NOTIFICATION_COMMAND_TYPE_QUIT
:
360 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
361 return "CLIENT_COMMUNICATION_UPDATE";
368 * Match trigger based on name and credentials only.
369 * Name duplication is NOT allowed for the same uid.
372 int match_trigger_by_name_uid(struct cds_lfht_node
*node
,
376 const char *element_trigger_name
;
377 const char *key_name
;
378 enum lttng_trigger_status status
;
379 const struct lttng_credentials
*key_creds
;
380 const struct lttng_credentials
*node_creds
;
381 const struct lttng_trigger
*trigger_key
=
382 (const struct lttng_trigger
*) key
;
383 const struct lttng_trigger_ht_element
*trigger_ht_element
=
384 caa_container_of(node
,
385 struct lttng_trigger_ht_element
,
388 status
= lttng_trigger_get_name(trigger_ht_element
->trigger
,
389 &element_trigger_name
);
390 element_trigger_name
= status
== LTTNG_TRIGGER_STATUS_OK
?
391 element_trigger_name
: NULL
;
393 status
= lttng_trigger_get_name(trigger_key
, &key_name
);
394 key_name
= status
== LTTNG_TRIGGER_STATUS_OK
? key_name
: NULL
;
398 * Consider null names as not equal. This is to maintain backwards
399 * compatibility with pre-2.13 anonymous triggers. Multiples anonymous
400 * triggers are allowed for a given user.
402 if (!element_trigger_name
|| !key_name
) {
406 if (strcmp(element_trigger_name
, key_name
) != 0) {
410 /* Compare the owners' UIDs. */
411 key_creds
= lttng_trigger_get_credentials(trigger_key
);
412 node_creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
414 match
= lttng_credentials_is_equal_uid(key_creds
, node_creds
);
421 * Hash trigger based on name and credentials only.
424 unsigned long hash_trigger_by_name_uid(const struct lttng_trigger
*trigger
)
426 unsigned long hash
= 0;
427 const struct lttng_credentials
*trigger_creds
;
428 const char *trigger_name
;
429 enum lttng_trigger_status status
;
431 status
= lttng_trigger_get_name(trigger
, &trigger_name
);
432 if (status
== LTTNG_TRIGGER_STATUS_OK
) {
433 hash
= hash_key_str(trigger_name
, lttng_ht_seed
);
436 trigger_creds
= lttng_trigger_get_credentials(trigger
);
437 hash
^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds
->uid
),
444 unsigned long hash_channel_key(struct channel_key
*key
)
446 unsigned long key_hash
= hash_key_u64(&key
->key
, lttng_ht_seed
);
447 unsigned long domain_hash
= hash_key_ulong(
448 (void *) (unsigned long) key
->domain
, lttng_ht_seed
);
450 return key_hash
^ domain_hash
;
454 unsigned long hash_client_socket(int socket
)
456 return hash_key_ulong((void *) (unsigned long) socket
, lttng_ht_seed
);
460 unsigned long hash_client_id(notification_client_id id
)
462 return hash_key_u64(&id
, lttng_ht_seed
);
466 * Get the type of object to which a given condition applies. Bindings let
467 * the notification system evaluate a trigger's condition when a given
468 * object's state is updated.
470 * For instance, a condition bound to a channel will be evaluated everytime
471 * the channel's state is changed by a channel monitoring sample.
474 enum lttng_object_type
get_condition_binding_object(
475 const struct lttng_condition
*condition
)
477 switch (lttng_condition_get_type(condition
)) {
478 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
479 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
480 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
481 return LTTNG_OBJECT_TYPE_CHANNEL
;
482 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
483 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
484 return LTTNG_OBJECT_TYPE_SESSION
;
485 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
486 return LTTNG_OBJECT_TYPE_NONE
;
488 return LTTNG_OBJECT_TYPE_UNKNOWN
;
493 void free_channel_info_rcu(struct rcu_head
*node
)
495 free(caa_container_of(node
, struct channel_info
, rcu_node
));
499 void channel_info_destroy(struct channel_info
*channel_info
)
505 if (channel_info
->session_info
) {
506 session_info_remove_channel(channel_info
->session_info
,
508 session_info_put(channel_info
->session_info
);
510 if (channel_info
->name
) {
511 free(channel_info
->name
);
513 call_rcu(&channel_info
->rcu_node
, free_channel_info_rcu
);
517 void free_session_info_rcu(struct rcu_head
*node
)
519 free(caa_container_of(node
, struct session_info
, rcu_node
));
522 /* Don't call directly, use the ref-counting mechanism. */
524 void session_info_destroy(void *_data
)
526 struct session_info
*session_info
= _data
;
529 assert(session_info
);
530 if (session_info
->channel_infos_ht
) {
531 ret
= cds_lfht_destroy(session_info
->channel_infos_ht
, NULL
);
533 ERR("Failed to destroy channel information hash table");
536 lttng_session_trigger_list_destroy(session_info
->trigger_list
);
539 cds_lfht_del(session_info
->sessions_ht
,
540 &session_info
->sessions_ht_node
);
542 free(session_info
->name
);
543 call_rcu(&session_info
->rcu_node
, free_session_info_rcu
);
547 void session_info_get(struct session_info
*session_info
)
552 lttng_ref_get(&session_info
->ref
);
556 void session_info_put(struct session_info
*session_info
)
561 lttng_ref_put(&session_info
->ref
);
565 struct session_info
*session_info_create(const char *name
, uid_t uid
, gid_t gid
,
566 struct lttng_session_trigger_list
*trigger_list
,
567 struct cds_lfht
*sessions_ht
)
569 struct session_info
*session_info
;
573 session_info
= zmalloc(sizeof(*session_info
));
577 lttng_ref_init(&session_info
->ref
, session_info_destroy
);
579 session_info
->channel_infos_ht
= cds_lfht_new(DEFAULT_HT_SIZE
,
580 1, 0, CDS_LFHT_AUTO_RESIZE
| CDS_LFHT_ACCOUNTING
, NULL
);
581 if (!session_info
->channel_infos_ht
) {
585 cds_lfht_node_init(&session_info
->sessions_ht_node
);
586 session_info
->name
= strdup(name
);
587 if (!session_info
->name
) {
590 session_info
->uid
= uid
;
591 session_info
->gid
= gid
;
592 session_info
->trigger_list
= trigger_list
;
593 session_info
->sessions_ht
= sessions_ht
;
597 session_info_put(session_info
);
602 void session_info_add_channel(struct session_info
*session_info
,
603 struct channel_info
*channel_info
)
606 cds_lfht_add(session_info
->channel_infos_ht
,
607 hash_channel_key(&channel_info
->key
),
608 &channel_info
->session_info_channels_ht_node
);
613 void session_info_remove_channel(struct session_info
*session_info
,
614 struct channel_info
*channel_info
)
617 cds_lfht_del(session_info
->channel_infos_ht
,
618 &channel_info
->session_info_channels_ht_node
);
623 struct channel_info
*channel_info_create(const char *channel_name
,
624 struct channel_key
*channel_key
, uint64_t channel_capacity
,
625 struct session_info
*session_info
)
627 struct channel_info
*channel_info
= zmalloc(sizeof(*channel_info
));
633 cds_lfht_node_init(&channel_info
->channels_ht_node
);
634 cds_lfht_node_init(&channel_info
->session_info_channels_ht_node
);
635 memcpy(&channel_info
->key
, channel_key
, sizeof(*channel_key
));
636 channel_info
->capacity
= channel_capacity
;
638 channel_info
->name
= strdup(channel_name
);
639 if (!channel_info
->name
) {
644 * Set the references between session and channel infos:
645 * - channel_info holds a strong reference to session_info
646 * - session_info holds a weak reference to channel_info
648 session_info_get(session_info
);
649 session_info_add_channel(session_info
, channel_info
);
650 channel_info
->session_info
= session_info
;
654 channel_info_destroy(channel_info
);
659 bool notification_client_list_get(struct notification_client_list
*list
)
661 return urcu_ref_get_unless_zero(&list
->ref
);
665 void free_notification_client_list_rcu(struct rcu_head
*node
)
667 free(caa_container_of(node
, struct notification_client_list
,
672 void notification_client_list_release(struct urcu_ref
*list_ref
)
674 struct notification_client_list
*list
=
675 container_of(list_ref
, typeof(*list
), ref
);
676 struct notification_client_list_element
*client_list_element
, *tmp
;
678 lttng_condition_put(list
->condition
);
680 if (list
->notification_trigger_clients_ht
) {
683 cds_lfht_del(list
->notification_trigger_clients_ht
,
684 &list
->notification_trigger_clients_ht_node
);
686 list
->notification_trigger_clients_ht
= NULL
;
688 cds_list_for_each_entry_safe(client_list_element
, tmp
,
689 &list
->clients_list
, node
) {
690 free(client_list_element
);
693 assert(cds_list_empty(&list
->triggers_list
));
695 pthread_mutex_destroy(&list
->lock
);
696 call_rcu(&list
->rcu_node
, free_notification_client_list_rcu
);
700 bool condition_applies_to_client(const struct lttng_condition
*condition
,
701 struct notification_client
*client
)
703 bool applies
= false;
704 struct lttng_condition_list_element
*condition_list_element
;
706 cds_list_for_each_entry(condition_list_element
, &client
->condition_list
,
708 applies
= lttng_condition_is_equal(
709 condition_list_element
->condition
,
720 struct notification_client_list
*notification_client_list_create(
721 struct notification_thread_state
*state
,
722 const struct lttng_condition
*condition
)
724 struct notification_client
*client
;
725 struct cds_lfht_iter iter
;
726 struct notification_client_list
*client_list
;
728 client_list
= zmalloc(sizeof(*client_list
));
730 PERROR("Failed to allocate notification client list");
734 pthread_mutex_init(&client_list
->lock
, NULL
);
736 * The trigger that owns the condition has the first reference to this
739 urcu_ref_init(&client_list
->ref
);
740 cds_lfht_node_init(&client_list
->notification_trigger_clients_ht_node
);
741 CDS_INIT_LIST_HEAD(&client_list
->clients_list
);
742 CDS_INIT_LIST_HEAD(&client_list
->triggers_list
);
745 * Create a copy of the condition so that it's independent of any
746 * trigger. The client list may outlive the trigger object (which owns
747 * the condition) that is used to create it.
749 client_list
->condition
= lttng_condition_copy(condition
);
751 /* Build a list of clients to which this new condition applies. */
752 cds_lfht_for_each_entry (state
->client_socket_ht
, &iter
, client
,
753 client_socket_ht_node
) {
754 struct notification_client_list_element
*client_list_element
;
756 if (!condition_applies_to_client(condition
, client
)) {
760 client_list_element
= zmalloc(sizeof(*client_list_element
));
761 if (!client_list_element
) {
762 goto error_put_client_list
;
765 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
766 client_list_element
->client
= client
;
767 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
770 client_list
->notification_trigger_clients_ht
=
771 state
->notification_trigger_clients_ht
;
775 * Add the client list to the global list of client list.
777 cds_lfht_add_unique(state
->notification_trigger_clients_ht
,
778 lttng_condition_hash(client_list
->condition
),
779 match_client_list_condition
,
780 client_list
->condition
,
781 &client_list
->notification_trigger_clients_ht_node
);
785 error_put_client_list
:
786 notification_client_list_put(client_list
);
793 void notification_client_list_put(struct notification_client_list
*list
)
798 return urcu_ref_put(&list
->ref
, notification_client_list_release
);
801 /* Provides a reference to the returned list. */
803 struct notification_client_list
*get_client_list_from_condition(
804 struct notification_thread_state
*state
,
805 const struct lttng_condition
*condition
)
807 struct cds_lfht_node
*node
;
808 struct cds_lfht_iter iter
;
809 struct notification_client_list
*list
= NULL
;
812 cds_lfht_lookup(state
->notification_trigger_clients_ht
,
813 lttng_condition_hash(condition
),
814 match_client_list_condition
,
817 node
= cds_lfht_iter_get_node(&iter
);
819 list
= container_of(node
, struct notification_client_list
,
820 notification_trigger_clients_ht_node
);
821 list
= notification_client_list_get(list
) ? list
: NULL
;
829 int evaluate_channel_condition_for_client(
830 const struct lttng_condition
*condition
,
831 struct notification_thread_state
*state
,
832 struct lttng_evaluation
**evaluation
,
833 uid_t
*session_uid
, gid_t
*session_gid
)
836 struct cds_lfht_iter iter
;
837 struct cds_lfht_node
*node
;
838 struct channel_info
*channel_info
= NULL
;
839 struct channel_key
*channel_key
= NULL
;
840 struct channel_state_sample
*last_sample
= NULL
;
841 struct lttng_channel_trigger_list
*channel_trigger_list
= NULL
;
845 /* Find the channel associated with the condition. */
846 cds_lfht_for_each_entry(state
->channel_triggers_ht
, &iter
,
847 channel_trigger_list
, channel_triggers_ht_node
) {
848 struct lttng_trigger_list_element
*element
;
850 cds_list_for_each_entry(element
, &channel_trigger_list
->list
, node
) {
851 const struct lttng_condition
*current_condition
=
852 lttng_trigger_get_const_condition(
855 assert(current_condition
);
856 if (!lttng_condition_is_equal(condition
,
857 current_condition
)) {
861 /* Found the trigger, save the channel key. */
862 channel_key
= &channel_trigger_list
->channel_key
;
866 /* The channel key was found stop iteration. */
872 /* No channel found; normal exit. */
873 DBG("No known channel associated with newly subscribed-to condition");
878 /* Fetch channel info for the matching channel. */
879 cds_lfht_lookup(state
->channels_ht
,
880 hash_channel_key(channel_key
),
884 node
= cds_lfht_iter_get_node(&iter
);
886 channel_info
= caa_container_of(node
, struct channel_info
,
889 /* Retrieve the channel's last sample, if it exists. */
890 cds_lfht_lookup(state
->channel_state_ht
,
891 hash_channel_key(channel_key
),
892 match_channel_state_sample
,
895 node
= cds_lfht_iter_get_node(&iter
);
897 last_sample
= caa_container_of(node
,
898 struct channel_state_sample
,
899 channel_state_ht_node
);
901 /* Nothing to evaluate, no sample was ever taken. Normal exit */
902 DBG("No channel sample associated with newly subscribed-to condition");
907 ret
= evaluate_buffer_condition(condition
, evaluation
, state
,
909 0, channel_info
->session_info
->consumed_data_size
,
912 WARN("Fatal error occurred while evaluating a newly subscribed-to condition");
916 *session_uid
= channel_info
->session_info
->uid
;
917 *session_gid
= channel_info
->session_info
->gid
;
924 const char *get_condition_session_name(const struct lttng_condition
*condition
)
926 const char *session_name
= NULL
;
927 enum lttng_condition_status status
;
929 switch (lttng_condition_get_type(condition
)) {
930 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
931 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
932 status
= lttng_condition_buffer_usage_get_session_name(
933 condition
, &session_name
);
935 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
936 status
= lttng_condition_session_consumed_size_get_session_name(
937 condition
, &session_name
);
939 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
940 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
941 status
= lttng_condition_session_rotation_get_session_name(
942 condition
, &session_name
);
947 if (status
!= LTTNG_CONDITION_STATUS_OK
) {
948 ERR("Failed to retrieve session rotation condition's session name");
956 int evaluate_session_condition_for_client(
957 const struct lttng_condition
*condition
,
958 struct notification_thread_state
*state
,
959 struct lttng_evaluation
**evaluation
,
960 uid_t
*session_uid
, gid_t
*session_gid
)
963 struct cds_lfht_iter iter
;
964 struct cds_lfht_node
*node
;
965 const char *session_name
;
966 struct session_info
*session_info
= NULL
;
969 session_name
= get_condition_session_name(condition
);
971 /* Find the session associated with the trigger. */
972 cds_lfht_lookup(state
->sessions_ht
,
973 hash_key_str(session_name
, lttng_ht_seed
),
977 node
= cds_lfht_iter_get_node(&iter
);
979 DBG("No known session matching name \"%s\"",
985 session_info
= caa_container_of(node
, struct session_info
,
987 session_info_get(session_info
);
990 * Evaluation is performed in-line here since only one type of
991 * session-bound condition is handled for the moment.
993 switch (lttng_condition_get_type(condition
)) {
994 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
995 if (!session_info
->rotation
.ongoing
) {
997 goto end_session_put
;
1000 *evaluation
= lttng_evaluation_session_rotation_ongoing_create(
1001 session_info
->rotation
.id
);
1004 ERR("Failed to create session rotation ongoing evaluation for session \"%s\"",
1005 session_info
->name
);
1007 goto end_session_put
;
1013 goto end_session_put
;
1016 *session_uid
= session_info
->uid
;
1017 *session_gid
= session_info
->gid
;
1020 session_info_put(session_info
);
1027 int evaluate_condition_for_client(const struct lttng_trigger
*trigger
,
1028 const struct lttng_condition
*condition
,
1029 struct notification_client
*client
,
1030 struct notification_thread_state
*state
)
1033 struct lttng_evaluation
*evaluation
= NULL
;
1034 struct notification_client_list client_list
= {
1035 .lock
= PTHREAD_MUTEX_INITIALIZER
,
1037 struct notification_client_list_element client_list_element
= { 0 };
1038 uid_t object_uid
= 0;
1039 gid_t object_gid
= 0;
1046 switch (get_condition_binding_object(condition
)) {
1047 case LTTNG_OBJECT_TYPE_SESSION
:
1048 ret
= evaluate_session_condition_for_client(condition
, state
,
1049 &evaluation
, &object_uid
, &object_gid
);
1051 case LTTNG_OBJECT_TYPE_CHANNEL
:
1052 ret
= evaluate_channel_condition_for_client(condition
, state
,
1053 &evaluation
, &object_uid
, &object_gid
);
1055 case LTTNG_OBJECT_TYPE_NONE
:
1056 DBG("Newly subscribed-to condition not bound to object, nothing to evaluate");
1059 case LTTNG_OBJECT_TYPE_UNKNOWN
:
1069 /* Evaluation yielded nothing. Normal exit. */
1070 DBG("Newly subscribed-to condition evaluated to false, nothing to report to client");
1076 * Create a temporary client list with the client currently
1079 cds_lfht_node_init(&client_list
.notification_trigger_clients_ht_node
);
1080 CDS_INIT_LIST_HEAD(&client_list
.clients_list
);
1082 CDS_INIT_LIST_HEAD(&client_list_element
.node
);
1083 client_list_element
.client
= client
;
1084 cds_list_add(&client_list_element
.node
, &client_list
.clients_list
);
1086 /* Send evaluation result to the newly-subscribed client. */
1087 DBG("Newly subscribed-to condition evaluated to true, notifying client");
1088 ret
= send_evaluation_to_clients(trigger
, evaluation
, &client_list
,
1089 state
, object_uid
, object_gid
);
1096 int notification_thread_client_subscribe(struct notification_client
*client
,
1097 struct lttng_condition
*condition
,
1098 struct notification_thread_state
*state
,
1099 enum lttng_notification_channel_status
*_status
)
1102 struct notification_client_list
*client_list
= NULL
;
1103 struct lttng_condition_list_element
*condition_list_element
= NULL
;
1104 struct notification_client_list_element
*client_list_element
= NULL
;
1105 struct lttng_trigger_ht_element
*trigger_ht_element
;
1106 enum lttng_notification_channel_status status
=
1107 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1110 * Ensure that the client has not already subscribed to this condition
1113 cds_list_for_each_entry(condition_list_element
, &client
->condition_list
, node
) {
1114 if (lttng_condition_is_equal(condition_list_element
->condition
,
1116 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED
;
1121 condition_list_element
= zmalloc(sizeof(*condition_list_element
));
1122 if (!condition_list_element
) {
1126 client_list_element
= zmalloc(sizeof(*client_list_element
));
1127 if (!client_list_element
) {
1133 * Add the newly-subscribed condition to the client's subscription list.
1135 CDS_INIT_LIST_HEAD(&condition_list_element
->node
);
1136 condition_list_element
->condition
= condition
;
1138 cds_list_add(&condition_list_element
->node
, &client
->condition_list
);
1140 client_list
= get_client_list_from_condition(
1141 state
, condition_list_element
->condition
);
1144 * No notification-emiting trigger registered with this
1145 * condition. We don't evaluate the condition right away
1146 * since this trigger is not registered yet.
1148 free(client_list_element
);
1153 * The condition to which the client just subscribed is evaluated
1154 * at this point so that conditions that are already TRUE result
1155 * in a notification being sent out.
1157 * Note the iteration on all triggers which share an identical
1158 * `condition` than the one to which the client is registering. This is
1159 * done to ensure that the client receives a distinct notification for
1160 * all triggers that have a `notify` action that have this condition.
1162 pthread_mutex_lock(&client_list
->lock
);
1163 cds_list_for_each_entry(trigger_ht_element
,
1164 &client_list
->triggers_list
, client_list_trigger_node
) {
1165 if (evaluate_condition_for_client(trigger_ht_element
->trigger
, condition_list_element
->condition
,
1167 WARN("Evaluation of a condition on client subscription failed, aborting.");
1169 free(client_list_element
);
1170 pthread_mutex_unlock(&client_list
->lock
);
1174 pthread_mutex_unlock(&client_list
->lock
);
1177 * Add the client to the list of clients interested in a given trigger
1178 * if a "notification" trigger with a corresponding condition was
1181 client_list_element
->client
= client
;
1182 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
1184 pthread_mutex_lock(&client_list
->lock
);
1185 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
1186 pthread_mutex_unlock(&client_list
->lock
);
1192 notification_client_list_put(client_list
);
1194 lttng_condition_destroy(condition
);
1197 free(condition_list_element
);
1198 free(client_list_element
);
1199 lttng_condition_destroy(condition
);
1204 int notification_thread_client_unsubscribe(
1205 struct notification_client
*client
,
1206 struct lttng_condition
*condition
,
1207 struct notification_thread_state
*state
,
1208 enum lttng_notification_channel_status
*_status
)
1210 struct notification_client_list
*client_list
;
1211 struct lttng_condition_list_element
*condition_list_element
,
1213 struct notification_client_list_element
*client_list_element
,
1215 bool condition_found
= false;
1216 enum lttng_notification_channel_status status
=
1217 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1219 /* Remove the condition from the client's condition list. */
1220 cds_list_for_each_entry_safe(condition_list_element
, condition_tmp
,
1221 &client
->condition_list
, node
) {
1222 if (!lttng_condition_is_equal(condition_list_element
->condition
,
1227 cds_list_del(&condition_list_element
->node
);
1229 * The caller may be iterating on the client's conditions to
1230 * tear down a client's connection. In this case, the condition
1231 * will be destroyed at the end.
1233 if (condition
!= condition_list_element
->condition
) {
1234 lttng_condition_destroy(
1235 condition_list_element
->condition
);
1237 free(condition_list_element
);
1238 condition_found
= true;
1242 if (!condition_found
) {
1243 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION
;
1248 * Remove the client from the list of clients interested the trigger
1249 * matching the condition.
1251 client_list
= get_client_list_from_condition(state
, condition
);
1256 pthread_mutex_lock(&client_list
->lock
);
1257 cds_list_for_each_entry_safe(client_list_element
, client_tmp
,
1258 &client_list
->clients_list
, node
) {
1259 if (client_list_element
->client
->id
!= client
->id
) {
1262 cds_list_del(&client_list_element
->node
);
1263 free(client_list_element
);
1266 pthread_mutex_unlock(&client_list
->lock
);
1267 notification_client_list_put(client_list
);
1270 lttng_condition_destroy(condition
);
1278 void free_notification_client_rcu(struct rcu_head
*node
)
1280 free(caa_container_of(node
, struct notification_client
, rcu_node
));
1284 void notification_client_destroy(struct notification_client
*client
,
1285 struct notification_thread_state
*state
)
1292 * The client object is not reachable by other threads, no need to lock
1295 if (client
->socket
>= 0) {
1296 (void) lttcomm_close_unix_sock(client
->socket
);
1297 client
->socket
= -1;
1299 client
->communication
.active
= false;
1300 lttng_payload_reset(&client
->communication
.inbound
.payload
);
1301 lttng_payload_reset(&client
->communication
.outbound
.payload
);
1302 pthread_mutex_destroy(&client
->lock
);
1303 call_rcu(&client
->rcu_node
, free_notification_client_rcu
);
1307 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1311 struct notification_client
*get_client_from_socket(int socket
,
1312 struct notification_thread_state
*state
)
1314 struct cds_lfht_iter iter
;
1315 struct cds_lfht_node
*node
;
1316 struct notification_client
*client
= NULL
;
1318 cds_lfht_lookup(state
->client_socket_ht
,
1319 hash_client_socket(socket
),
1320 match_client_socket
,
1321 (void *) (unsigned long) socket
,
1323 node
= cds_lfht_iter_get_node(&iter
);
1328 client
= caa_container_of(node
, struct notification_client
,
1329 client_socket_ht_node
);
1335 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1339 struct notification_client
*get_client_from_id(notification_client_id id
,
1340 struct notification_thread_state
*state
)
1342 struct cds_lfht_iter iter
;
1343 struct cds_lfht_node
*node
;
1344 struct notification_client
*client
= NULL
;
1346 cds_lfht_lookup(state
->client_id_ht
,
1351 node
= cds_lfht_iter_get_node(&iter
);
1356 client
= caa_container_of(node
, struct notification_client
,
1363 bool buffer_usage_condition_applies_to_channel(
1364 const struct lttng_condition
*condition
,
1365 const struct channel_info
*channel_info
)
1367 enum lttng_condition_status status
;
1368 enum lttng_domain_type condition_domain
;
1369 const char *condition_session_name
= NULL
;
1370 const char *condition_channel_name
= NULL
;
1372 status
= lttng_condition_buffer_usage_get_domain_type(condition
,
1374 assert(status
== LTTNG_CONDITION_STATUS_OK
);
1375 if (channel_info
->key
.domain
!= condition_domain
) {
1379 status
= lttng_condition_buffer_usage_get_session_name(
1380 condition
, &condition_session_name
);
1381 assert((status
== LTTNG_CONDITION_STATUS_OK
) && condition_session_name
);
1383 status
= lttng_condition_buffer_usage_get_channel_name(
1384 condition
, &condition_channel_name
);
1385 assert((status
== LTTNG_CONDITION_STATUS_OK
) && condition_channel_name
);
1387 if (strcmp(channel_info
->session_info
->name
, condition_session_name
)) {
1390 if (strcmp(channel_info
->name
, condition_channel_name
)) {
1400 bool session_consumed_size_condition_applies_to_channel(
1401 const struct lttng_condition
*condition
,
1402 const struct channel_info
*channel_info
)
1404 enum lttng_condition_status status
;
1405 const char *condition_session_name
= NULL
;
1407 status
= lttng_condition_session_consumed_size_get_session_name(
1408 condition
, &condition_session_name
);
1409 assert((status
== LTTNG_CONDITION_STATUS_OK
) && condition_session_name
);
1411 if (strcmp(channel_info
->session_info
->name
, condition_session_name
)) {
1421 bool trigger_applies_to_channel(const struct lttng_trigger
*trigger
,
1422 const struct channel_info
*channel_info
)
1424 const struct lttng_condition
*condition
;
1425 bool trigger_applies
;
1427 condition
= lttng_trigger_get_const_condition(trigger
);
1432 switch (lttng_condition_get_type(condition
)) {
1433 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
1434 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
1435 trigger_applies
= buffer_usage_condition_applies_to_channel(
1436 condition
, channel_info
);
1438 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1439 trigger_applies
= session_consumed_size_condition_applies_to_channel(
1440 condition
, channel_info
);
1446 return trigger_applies
;
1451 /* Must be called with RCU read lock held. */
1453 struct lttng_session_trigger_list
*get_session_trigger_list(
1454 struct notification_thread_state
*state
,
1455 const char *session_name
)
1457 struct lttng_session_trigger_list
*list
= NULL
;
1458 struct cds_lfht_node
*node
;
1459 struct cds_lfht_iter iter
;
1461 cds_lfht_lookup(state
->session_triggers_ht
,
1462 hash_key_str(session_name
, lttng_ht_seed
),
1463 match_session_trigger_list
,
1466 node
= cds_lfht_iter_get_node(&iter
);
1469 * Not an error, the list of triggers applying to that session
1470 * will be initialized when the session is created.
1472 DBG("No trigger list found for session \"%s\" as it is not yet known to the notification system",
1477 list
= caa_container_of(node
,
1478 struct lttng_session_trigger_list
,
1479 session_triggers_ht_node
);
1485 * Allocate an empty lttng_session_trigger_list for the session named
1488 * No ownership of 'session_name' is assumed by the session trigger list.
1489 * It is the caller's responsability to ensure the session name is alive
1490 * for as long as this list is.
1493 struct lttng_session_trigger_list
*lttng_session_trigger_list_create(
1494 const char *session_name
,
1495 struct cds_lfht
*session_triggers_ht
)
1497 struct lttng_session_trigger_list
*list
;
1499 list
= zmalloc(sizeof(*list
));
1503 list
->session_name
= session_name
;
1504 CDS_INIT_LIST_HEAD(&list
->list
);
1505 cds_lfht_node_init(&list
->session_triggers_ht_node
);
1506 list
->session_triggers_ht
= session_triggers_ht
;
1509 /* Publish the list through the session_triggers_ht. */
1510 cds_lfht_add(session_triggers_ht
,
1511 hash_key_str(session_name
, lttng_ht_seed
),
1512 &list
->session_triggers_ht_node
);
1519 void free_session_trigger_list_rcu(struct rcu_head
*node
)
1521 free(caa_container_of(node
, struct lttng_session_trigger_list
,
1526 void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list
*list
)
1528 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1530 /* Empty the list element by element, and then free the list itself. */
1531 cds_list_for_each_entry_safe(trigger_list_element
, tmp
,
1532 &list
->list
, node
) {
1533 cds_list_del(&trigger_list_element
->node
);
1534 free(trigger_list_element
);
1537 /* Unpublish the list from the session_triggers_ht. */
1538 cds_lfht_del(list
->session_triggers_ht
,
1539 &list
->session_triggers_ht_node
);
1541 call_rcu(&list
->rcu_node
, free_session_trigger_list_rcu
);
1545 int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
1546 struct lttng_trigger
*trigger
)
1549 struct lttng_trigger_list_element
*new_element
=
1550 zmalloc(sizeof(*new_element
));
1556 CDS_INIT_LIST_HEAD(&new_element
->node
);
1557 new_element
->trigger
= trigger
;
1558 cds_list_add(&new_element
->node
, &list
->list
);
1564 bool trigger_applies_to_session(const struct lttng_trigger
*trigger
,
1565 const char *session_name
)
1567 bool applies
= false;
1568 const struct lttng_condition
*condition
;
1570 condition
= lttng_trigger_get_const_condition(trigger
);
1571 switch (lttng_condition_get_type(condition
)) {
1572 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1573 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1575 enum lttng_condition_status condition_status
;
1576 const char *condition_session_name
;
1578 condition_status
= lttng_condition_session_rotation_get_session_name(
1579 condition
, &condition_session_name
);
1580 if (condition_status
!= LTTNG_CONDITION_STATUS_OK
) {
1581 ERR("Failed to retrieve session rotation condition's session name");
1585 assert(condition_session_name
);
1586 applies
= !strcmp(condition_session_name
, session_name
);
1597 * Allocate and initialize an lttng_session_trigger_list which contains
1598 * all triggers that apply to the session named 'session_name'.
1600 * No ownership of 'session_name' is assumed by the session trigger list.
1601 * It is the caller's responsability to ensure the session name is alive
1602 * for as long as this list is.
1605 struct lttng_session_trigger_list
*lttng_session_trigger_list_build(
1606 const struct notification_thread_state
*state
,
1607 const char *session_name
)
1609 int trigger_count
= 0;
1610 struct lttng_session_trigger_list
*session_trigger_list
= NULL
;
1611 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
1612 struct cds_lfht_iter iter
;
1614 session_trigger_list
= lttng_session_trigger_list_create(session_name
,
1615 state
->session_triggers_ht
);
1617 /* Add all triggers applying to the session named 'session_name'. */
1618 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
1622 if (!trigger_applies_to_session(trigger_ht_element
->trigger
,
1627 ret
= lttng_session_trigger_list_add(session_trigger_list
,
1628 trigger_ht_element
->trigger
);
1636 DBG("Found %i triggers that apply to newly created session",
1638 return session_trigger_list
;
1640 lttng_session_trigger_list_destroy(session_trigger_list
);
1645 struct session_info
*find_or_create_session_info(
1646 struct notification_thread_state
*state
,
1647 const char *name
, uid_t uid
, gid_t gid
)
1649 struct session_info
*session
= NULL
;
1650 struct cds_lfht_node
*node
;
1651 struct cds_lfht_iter iter
;
1652 struct lttng_session_trigger_list
*trigger_list
;
1655 cds_lfht_lookup(state
->sessions_ht
,
1656 hash_key_str(name
, lttng_ht_seed
),
1660 node
= cds_lfht_iter_get_node(&iter
);
1662 DBG("Found session info of session \"%s\" (uid = %i, gid = %i)",
1664 session
= caa_container_of(node
, struct session_info
,
1666 assert(session
->uid
== uid
);
1667 assert(session
->gid
== gid
);
1668 session_info_get(session
);
1672 trigger_list
= lttng_session_trigger_list_build(state
, name
);
1673 if (!trigger_list
) {
1677 session
= session_info_create(name
, uid
, gid
, trigger_list
,
1678 state
->sessions_ht
);
1680 ERR("Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
1682 lttng_session_trigger_list_destroy(trigger_list
);
1685 trigger_list
= NULL
;
1687 cds_lfht_add(state
->sessions_ht
, hash_key_str(name
, lttng_ht_seed
),
1688 &session
->sessions_ht_node
);
1694 session_info_put(session
);
1699 int handle_notification_thread_command_add_channel(
1700 struct notification_thread_state
*state
,
1701 const char *session_name
, uid_t session_uid
, gid_t session_gid
,
1702 const char *channel_name
, enum lttng_domain_type channel_domain
,
1703 uint64_t channel_key_int
, uint64_t channel_capacity
,
1704 enum lttng_error_code
*cmd_result
)
1706 struct cds_list_head trigger_list
;
1707 struct channel_info
*new_channel_info
= NULL
;
1708 struct channel_key channel_key
= {
1709 .key
= channel_key_int
,
1710 .domain
= channel_domain
,
1712 struct lttng_channel_trigger_list
*channel_trigger_list
= NULL
;
1713 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
1714 int trigger_count
= 0;
1715 struct cds_lfht_iter iter
;
1716 struct session_info
*session_info
= NULL
;
1718 DBG("Adding channel %s from session %s, channel key = %" PRIu64
" in %s domain",
1719 channel_name
, session_name
, channel_key_int
,
1720 lttng_domain_type_str(channel_domain
));
1722 CDS_INIT_LIST_HEAD(&trigger_list
);
1724 session_info
= find_or_create_session_info(state
, session_name
,
1725 session_uid
, session_gid
);
1726 if (!session_info
) {
1727 /* Allocation error or an internal error occurred. */
1731 new_channel_info
= channel_info_create(channel_name
, &channel_key
,
1732 channel_capacity
, session_info
);
1733 if (!new_channel_info
) {
1738 /* Build a list of all triggers applying to the new channel. */
1739 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
1741 struct lttng_trigger_list_element
*new_element
;
1743 if (!trigger_applies_to_channel(trigger_ht_element
->trigger
,
1744 new_channel_info
)) {
1748 new_element
= zmalloc(sizeof(*new_element
));
1753 CDS_INIT_LIST_HEAD(&new_element
->node
);
1754 new_element
->trigger
= trigger_ht_element
->trigger
;
1755 cds_list_add(&new_element
->node
, &trigger_list
);
1760 DBG("Found %i triggers that apply to newly added channel",
1762 channel_trigger_list
= zmalloc(sizeof(*channel_trigger_list
));
1763 if (!channel_trigger_list
) {
1766 channel_trigger_list
->channel_key
= new_channel_info
->key
;
1767 CDS_INIT_LIST_HEAD(&channel_trigger_list
->list
);
1768 cds_lfht_node_init(&channel_trigger_list
->channel_triggers_ht_node
);
1769 cds_list_splice(&trigger_list
, &channel_trigger_list
->list
);
1772 /* Add channel to the channel_ht which owns the channel_infos. */
1773 cds_lfht_add(state
->channels_ht
,
1774 hash_channel_key(&new_channel_info
->key
),
1775 &new_channel_info
->channels_ht_node
);
1777 * Add the list of triggers associated with this channel to the
1778 * channel_triggers_ht.
1780 cds_lfht_add(state
->channel_triggers_ht
,
1781 hash_channel_key(&new_channel_info
->key
),
1782 &channel_trigger_list
->channel_triggers_ht_node
);
1784 session_info_put(session_info
);
1785 *cmd_result
= LTTNG_OK
;
1788 channel_info_destroy(new_channel_info
);
1789 session_info_put(session_info
);
1794 void free_channel_trigger_list_rcu(struct rcu_head
*node
)
1796 free(caa_container_of(node
, struct lttng_channel_trigger_list
,
1801 void free_channel_state_sample_rcu(struct rcu_head
*node
)
1803 free(caa_container_of(node
, struct channel_state_sample
,
1808 int handle_notification_thread_command_remove_channel(
1809 struct notification_thread_state
*state
,
1810 uint64_t channel_key
, enum lttng_domain_type domain
,
1811 enum lttng_error_code
*cmd_result
)
1813 struct cds_lfht_node
*node
;
1814 struct cds_lfht_iter iter
;
1815 struct lttng_channel_trigger_list
*trigger_list
;
1816 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1817 struct channel_key key
= { .key
= channel_key
, .domain
= domain
};
1818 struct channel_info
*channel_info
;
1820 DBG("Removing channel key = %" PRIu64
" in %s domain",
1821 channel_key
, lttng_domain_type_str(domain
));
1825 cds_lfht_lookup(state
->channel_triggers_ht
,
1826 hash_channel_key(&key
),
1827 match_channel_trigger_list
,
1830 node
= cds_lfht_iter_get_node(&iter
);
1832 * There is a severe internal error if we are being asked to remove a
1833 * channel that doesn't exist.
1836 ERR("Channel being removed is unknown to the notification thread");
1840 /* Free the list of triggers associated with this channel. */
1841 trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
1842 channel_triggers_ht_node
);
1843 cds_list_for_each_entry_safe(trigger_list_element
, tmp
,
1844 &trigger_list
->list
, node
) {
1845 cds_list_del(&trigger_list_element
->node
);
1846 free(trigger_list_element
);
1848 cds_lfht_del(state
->channel_triggers_ht
, node
);
1849 call_rcu(&trigger_list
->rcu_node
, free_channel_trigger_list_rcu
);
1851 /* Free sampled channel state. */
1852 cds_lfht_lookup(state
->channel_state_ht
,
1853 hash_channel_key(&key
),
1854 match_channel_state_sample
,
1857 node
= cds_lfht_iter_get_node(&iter
);
1859 * This is expected to be NULL if the channel is destroyed before we
1860 * received a sample.
1863 struct channel_state_sample
*sample
= caa_container_of(node
,
1864 struct channel_state_sample
,
1865 channel_state_ht_node
);
1867 cds_lfht_del(state
->channel_state_ht
, node
);
1868 call_rcu(&sample
->rcu_node
, free_channel_state_sample_rcu
);
1871 /* Remove the channel from the channels_ht and free it. */
1872 cds_lfht_lookup(state
->channels_ht
,
1873 hash_channel_key(&key
),
1877 node
= cds_lfht_iter_get_node(&iter
);
1879 channel_info
= caa_container_of(node
, struct channel_info
,
1881 cds_lfht_del(state
->channels_ht
, node
);
1882 channel_info_destroy(channel_info
);
1885 *cmd_result
= LTTNG_OK
;
1890 int handle_notification_thread_command_session_rotation(
1891 struct notification_thread_state
*state
,
1892 enum notification_thread_command_type cmd_type
,
1893 const char *session_name
, uid_t session_uid
, gid_t session_gid
,
1894 uint64_t trace_archive_chunk_id
,
1895 struct lttng_trace_archive_location
*location
,
1896 enum lttng_error_code
*_cmd_result
)
1899 enum lttng_error_code cmd_result
= LTTNG_OK
;
1900 struct lttng_session_trigger_list
*trigger_list
;
1901 struct lttng_trigger_list_element
*trigger_list_element
;
1902 struct session_info
*session_info
;
1903 const struct lttng_credentials session_creds
= {
1904 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session_uid
),
1905 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session_gid
),
1910 session_info
= find_or_create_session_info(state
, session_name
,
1911 session_uid
, session_gid
);
1912 if (!session_info
) {
1913 /* Allocation error or an internal error occurred. */
1915 cmd_result
= LTTNG_ERR_NOMEM
;
1919 session_info
->rotation
.ongoing
=
1920 cmd_type
== NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
;
1921 session_info
->rotation
.id
= trace_archive_chunk_id
;
1922 trigger_list
= get_session_trigger_list(state
, session_name
);
1923 if (!trigger_list
) {
1924 DBG("No triggers applying to session \"%s\" found",
1929 cds_list_for_each_entry(trigger_list_element
, &trigger_list
->list
,
1931 const struct lttng_condition
*condition
;
1932 struct lttng_trigger
*trigger
;
1933 struct notification_client_list
*client_list
;
1934 struct lttng_evaluation
*evaluation
= NULL
;
1935 enum lttng_condition_type condition_type
;
1936 enum action_executor_status executor_status
;
1938 trigger
= trigger_list_element
->trigger
;
1939 condition
= lttng_trigger_get_const_condition(trigger
);
1941 condition_type
= lttng_condition_get_type(condition
);
1943 if (condition_type
== LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
&&
1944 cmd_type
!= NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
) {
1946 } else if (condition_type
== LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
&&
1947 cmd_type
!= NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
) {
1951 client_list
= get_client_list_from_condition(state
, condition
);
1952 if (cmd_type
== NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
) {
1953 evaluation
= lttng_evaluation_session_rotation_ongoing_create(
1954 trace_archive_chunk_id
);
1956 evaluation
= lttng_evaluation_session_rotation_completed_create(
1957 trace_archive_chunk_id
, location
);
1961 /* Internal error */
1963 cmd_result
= LTTNG_ERR_UNK
;
1968 * Ownership of `evaluation` transferred to the action executor
1969 * no matter the result.
1971 executor_status
= action_executor_enqueue_trigger(
1972 state
->executor
, trigger
, evaluation
,
1973 &session_creds
, client_list
);
1975 switch (executor_status
) {
1976 case ACTION_EXECUTOR_STATUS_OK
:
1978 case ACTION_EXECUTOR_STATUS_ERROR
:
1979 case ACTION_EXECUTOR_STATUS_INVALID
:
1981 * TODO Add trigger identification (name/id) when
1982 * it is added to the API.
1984 ERR("Fatal error occurred while enqueuing action associated with session rotation trigger");
1987 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
1989 * TODO Add trigger identification (name/id) when
1990 * it is added to the API.
1992 * Not a fatal error.
1994 WARN("No space left when enqueuing action associated with session rotation trigger");
2002 notification_client_list_put(client_list
);
2003 if (caa_unlikely(ret
)) {
2008 session_info_put(session_info
);
2009 *_cmd_result
= cmd_result
;
2015 int handle_notification_thread_command_add_tracer_event_source(
2016 struct notification_thread_state
*state
,
2017 int tracer_event_source_fd
,
2018 enum lttng_domain_type domain_type
,
2019 enum lttng_error_code
*_cmd_result
)
2022 enum lttng_error_code cmd_result
= LTTNG_OK
;
2023 struct notification_event_tracer_event_source_element
*element
= NULL
;
2025 element
= zmalloc(sizeof(*element
));
2027 cmd_result
= LTTNG_ERR_NOMEM
;
2032 element
->fd
= tracer_event_source_fd
;
2033 element
->domain
= domain_type
;
2035 cds_list_add(&element
->node
, &state
->tracer_event_sources_list
);
2037 DBG3("Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'",
2038 tracer_event_source_fd
,
2039 lttng_domain_type_str(domain_type
));
2041 /* Adding the read side pipe to the event poll. */
2042 ret
= lttng_poll_add(&state
->events
, tracer_event_source_fd
, LPOLLPRI
| LPOLLIN
| LPOLLERR
);
2044 ERR("Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'",
2045 tracer_event_source_fd
,
2046 lttng_domain_type_str(element
->domain
));
2047 cds_list_del(&element
->node
);
2052 element
->is_fd_in_poll_set
= true;
2055 *_cmd_result
= cmd_result
;
2060 int drain_event_notifier_notification_pipe(
2061 struct notification_thread_state
*state
,
2062 int pipe
, enum lttng_domain_type domain
)
2064 struct lttng_poll_event events
= {0};
2067 ret
= lttng_poll_create(&events
, 1, LTTNG_CLOEXEC
);
2069 ERR("Error creating lttng_poll_event");
2073 ret
= lttng_poll_add(&events
, pipe
, LPOLLIN
);
2075 ERR("Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d",
2082 * Continue to consume notifications as long as there are new
2083 * ones coming in. The tracer has been asked to stop producing
2086 * LPOLLIN is explicitly checked since LPOLLHUP is implicitly
2087 * monitored (on Linux, at least) and will be returned when
2088 * the pipe is closed but empty.
2090 ret
= lttng_poll_wait_interruptible(&events
, 0);
2091 if (ret
== 0 || (LTTNG_POLL_GETEV(&events
, 0) & LPOLLIN
) == 0) {
2092 /* No more notification to be read on this pipe. */
2095 } else if (ret
< 0) {
2096 PERROR("Failed on lttng_poll_wait_interruptible() call");
2101 ret
= handle_one_event_notifier_notification(state
, pipe
, domain
);
2103 ERR("Error consuming an event notifier notification from pipe: fd = %d",
2108 lttng_poll_clean(&events
);
2113 struct notification_event_tracer_event_source_element
*
2114 find_tracer_event_source_element(struct notification_thread_state
*state
,
2115 int tracer_event_source_fd
)
2117 struct notification_event_tracer_event_source_element
*source_element
;
2119 cds_list_for_each_entry(source_element
,
2120 &state
->tracer_event_sources_list
, node
) {
2121 if (source_element
->fd
== tracer_event_source_fd
) {
2126 source_element
= NULL
;
2128 return source_element
;
2132 int remove_tracer_event_source_from_pollset(
2133 struct notification_thread_state
*state
,
2134 struct notification_event_tracer_event_source_element
*source_element
)
2138 assert(source_element
->is_fd_in_poll_set
);
2140 DBG3("Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2142 lttng_domain_type_str(source_element
->domain
));
2144 /* Removing the fd from the event poll set. */
2145 ret
= lttng_poll_del(&state
->events
, source_element
->fd
);
2147 ERR("Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2149 lttng_domain_type_str(source_element
->domain
));
2154 source_element
->is_fd_in_poll_set
= false;
2157 * Force the notification thread to restart the poll() loop to ensure
2158 * that any events from the removed fd are removed.
2160 state
->restart_poll
= true;
2162 ret
= drain_event_notifier_notification_pipe(state
, source_element
->fd
,
2163 source_element
->domain
);
2165 ERR("Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s",
2167 lttng_domain_type_str(source_element
->domain
));
2176 int handle_notification_thread_tracer_event_source_died(
2177 struct notification_thread_state
*state
,
2178 int tracer_event_source_fd
)
2181 struct notification_event_tracer_event_source_element
*source_element
;
2183 source_element
= find_tracer_event_source_element(state
,
2184 tracer_event_source_fd
);
2186 assert(source_element
);
2188 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2190 ERR("Failed to remove dead tracer event source from poll set");
2197 int handle_notification_thread_command_remove_tracer_event_source(
2198 struct notification_thread_state
*state
,
2199 int tracer_event_source_fd
,
2200 enum lttng_error_code
*_cmd_result
)
2203 enum lttng_error_code cmd_result
= LTTNG_OK
;
2204 struct notification_event_tracer_event_source_element
*source_element
= NULL
;
2206 source_element
= find_tracer_event_source_element(state
,
2207 tracer_event_source_fd
);
2209 assert(source_element
);
2211 /* Remove the tracer source from the list. */
2212 cds_list_del(&source_element
->node
);
2214 if (!source_element
->is_fd_in_poll_set
) {
2215 /* Skip the poll set removal. */
2219 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2221 ERR("Failed to remove tracer event source from poll set");
2222 cmd_result
= LTTNG_ERR_FATAL
;
2226 free(source_element
);
2227 *_cmd_result
= cmd_result
;
2231 static int handle_notification_thread_command_list_triggers(
2232 struct notification_thread_handle
*handle
,
2233 struct notification_thread_state
*state
,
2235 struct lttng_triggers
**triggers
,
2236 enum lttng_error_code
*_cmd_result
)
2239 enum lttng_error_code cmd_result
= LTTNG_OK
;
2240 struct cds_lfht_iter iter
;
2241 struct lttng_trigger_ht_element
*trigger_ht_element
;
2242 struct lttng_triggers
*local_triggers
= NULL
;
2243 const struct lttng_credentials
*creds
;
2247 local_triggers
= lttng_triggers_create();
2248 if (!local_triggers
) {
2249 /* Not a fatal error. */
2250 cmd_result
= LTTNG_ERR_NOMEM
;
2254 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
,
2255 trigger_ht_element
, node
) {
2257 * Only return the triggers to which the client has access.
2258 * The root user has visibility over all triggers.
2260 creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
2261 if (client_uid
!= lttng_credentials_get_uid(creds
) && client_uid
!= 0) {
2265 ret
= lttng_triggers_add(local_triggers
,
2266 trigger_ht_element
->trigger
);
2268 /* Not a fatal error. */
2270 cmd_result
= LTTNG_ERR_NOMEM
;
2275 /* Transferring ownership to the caller. */
2276 *triggers
= local_triggers
;
2277 local_triggers
= NULL
;
2281 lttng_triggers_destroy(local_triggers
);
2282 *_cmd_result
= cmd_result
;
2286 static inline void get_trigger_info_for_log(const struct lttng_trigger
*trigger
,
2287 const char **trigger_name
,
2288 uid_t
*trigger_owner_uid
)
2290 enum lttng_trigger_status trigger_status
;
2292 trigger_status
= lttng_trigger_get_name(trigger
, trigger_name
);
2293 switch (trigger_status
) {
2294 case LTTNG_TRIGGER_STATUS_OK
:
2296 case LTTNG_TRIGGER_STATUS_UNSET
:
2297 *trigger_name
= "(anonymous)";
2303 trigger_status
= lttng_trigger_get_owner_uid(trigger
,
2305 assert(trigger_status
== LTTNG_TRIGGER_STATUS_OK
);
2308 static int handle_notification_thread_command_get_trigger(
2309 struct notification_thread_state
*state
,
2310 const struct lttng_trigger
*trigger
,
2311 struct lttng_trigger
**registered_trigger
,
2312 enum lttng_error_code
*_cmd_result
)
2315 struct cds_lfht_iter iter
;
2316 struct lttng_trigger_ht_element
*trigger_ht_element
;
2317 enum lttng_error_code cmd_result
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
2318 const char *trigger_name
;
2319 uid_t trigger_owner_uid
;
2323 cds_lfht_for_each_entry(
2324 state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
2325 if (lttng_trigger_is_equal(
2326 trigger
, trigger_ht_element
->trigger
)) {
2327 /* Take one reference on the return trigger. */
2328 *registered_trigger
= trigger_ht_element
->trigger
;
2329 lttng_trigger_get(*registered_trigger
);
2331 cmd_result
= LTTNG_OK
;
2336 /* Not a fatal error if the trigger is not found. */
2337 get_trigger_info_for_log(trigger
, &trigger_name
, &trigger_owner_uid
);
2338 DBG("Failed to retrieve registered version of trigger: trigger name = '%s', trigger owner uid = %d",
2339 trigger_name
, (int) trigger_owner_uid
);
2345 *_cmd_result
= cmd_result
;
2350 bool condition_is_supported(struct lttng_condition
*condition
)
2354 switch (lttng_condition_get_type(condition
)) {
2355 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
2356 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
2359 enum lttng_domain_type domain
;
2361 ret
= lttng_condition_buffer_usage_get_domain_type(condition
,
2365 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2366 is_supported
= true;
2371 * Older kernel tracers don't expose the API to monitor their
2372 * buffers. Therefore, we reject triggers that require that
2373 * mechanism to be available to be evaluated.
2375 * Assume unsupported on error.
2377 is_supported
= kernel_supports_ring_buffer_snapshot_sample_positions() == 1;
2380 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
2382 const struct lttng_event_rule
*event_rule
;
2383 enum lttng_domain_type domain
;
2384 const enum lttng_condition_status status
=
2385 lttng_condition_event_rule_matches_get_rule(
2386 condition
, &event_rule
);
2388 assert(status
== LTTNG_CONDITION_STATUS_OK
);
2390 domain
= lttng_event_rule_get_domain_type(event_rule
);
2391 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2392 is_supported
= true;
2397 * Older kernel tracers can't emit notification. Therefore, we
2398 * reject triggers that require that mechanism to be available
2401 * Assume unsupported on error.
2403 is_supported
= kernel_supports_event_notifiers() == 1;
2407 is_supported
= true;
2410 return is_supported
;
2413 /* Must be called with RCU read lock held. */
2415 int bind_trigger_to_matching_session(struct lttng_trigger
*trigger
,
2416 struct notification_thread_state
*state
)
2419 const struct lttng_condition
*condition
;
2420 const char *session_name
;
2421 struct lttng_session_trigger_list
*trigger_list
;
2423 condition
= lttng_trigger_get_const_condition(trigger
);
2424 switch (lttng_condition_get_type(condition
)) {
2425 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
2426 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
2428 enum lttng_condition_status status
;
2430 status
= lttng_condition_session_rotation_get_session_name(
2431 condition
, &session_name
);
2432 if (status
!= LTTNG_CONDITION_STATUS_OK
) {
2433 ERR("Failed to bind trigger to session: unable to get 'session_rotation' condition's session name");
2444 trigger_list
= get_session_trigger_list(state
, session_name
);
2445 if (!trigger_list
) {
2446 DBG("Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system",
2452 DBG("Newly registered trigger bound to session \"%s\"",
2454 ret
= lttng_session_trigger_list_add(trigger_list
, trigger
);
2459 /* Must be called with RCU read lock held. */
2461 int bind_trigger_to_matching_channels(struct lttng_trigger
*trigger
,
2462 struct notification_thread_state
*state
)
2465 struct cds_lfht_node
*node
;
2466 struct cds_lfht_iter iter
;
2467 struct channel_info
*channel
;
2469 cds_lfht_for_each_entry(state
->channels_ht
, &iter
, channel
,
2471 struct lttng_trigger_list_element
*trigger_list_element
;
2472 struct lttng_channel_trigger_list
*trigger_list
;
2473 struct cds_lfht_iter lookup_iter
;
2475 if (!trigger_applies_to_channel(trigger
, channel
)) {
2479 cds_lfht_lookup(state
->channel_triggers_ht
,
2480 hash_channel_key(&channel
->key
),
2481 match_channel_trigger_list
,
2484 node
= cds_lfht_iter_get_node(&lookup_iter
);
2486 trigger_list
= caa_container_of(node
,
2487 struct lttng_channel_trigger_list
,
2488 channel_triggers_ht_node
);
2490 trigger_list_element
= zmalloc(sizeof(*trigger_list_element
));
2491 if (!trigger_list_element
) {
2495 CDS_INIT_LIST_HEAD(&trigger_list_element
->node
);
2496 trigger_list_element
->trigger
= trigger
;
2497 cds_list_add(&trigger_list_element
->node
, &trigger_list
->list
);
2498 DBG("Newly registered trigger bound to channel \"%s\"",
2506 bool is_trigger_action_notify(const struct lttng_trigger
*trigger
)
2508 bool is_notify
= false;
2509 unsigned int i
, count
;
2510 enum lttng_action_status action_status
;
2511 const struct lttng_action
*action
=
2512 lttng_trigger_get_const_action(trigger
);
2513 enum lttng_action_type action_type
;
2516 action_type
= lttng_action_get_type(action
);
2517 if (action_type
== LTTNG_ACTION_TYPE_NOTIFY
) {
2520 } else if (action_type
!= LTTNG_ACTION_TYPE_LIST
) {
2524 action_status
= lttng_action_list_get_count(action
, &count
);
2525 assert(action_status
== LTTNG_ACTION_STATUS_OK
);
2527 for (i
= 0; i
< count
; i
++) {
2528 const struct lttng_action
*inner_action
=
2529 lttng_action_list_get_at_index(
2532 action_type
= lttng_action_get_type(inner_action
);
2533 if (action_type
== LTTNG_ACTION_TYPE_NOTIFY
) {
2543 static bool trigger_name_taken(struct notification_thread_state
*state
,
2544 const struct lttng_trigger
*trigger
)
2546 struct cds_lfht_iter iter
;
2549 * No duplicata is allowed in the triggers_by_name_uid_ht.
2550 * The match is done against the trigger name and uid.
2552 cds_lfht_lookup(state
->triggers_by_name_uid_ht
,
2553 hash_trigger_by_name_uid(trigger
),
2554 match_trigger_by_name_uid
,
2557 return !!cds_lfht_iter_get_node(&iter
);
2561 enum lttng_error_code
generate_trigger_name(
2562 struct notification_thread_state
*state
,
2563 struct lttng_trigger
*trigger
, const char **name
)
2565 enum lttng_error_code ret_code
= LTTNG_OK
;
2567 enum lttng_trigger_status status
;
2570 const int ret
= lttng_trigger_generate_name(trigger
,
2571 state
->trigger_id
.name_offset
++);
2573 /* The only reason this can fail right now. */
2574 ret_code
= LTTNG_ERR_NOMEM
;
2578 status
= lttng_trigger_get_name(trigger
, name
);
2579 assert(status
== LTTNG_TRIGGER_STATUS_OK
);
2581 taken
= trigger_name_taken(state
, trigger
);
2582 } while (taken
|| state
->trigger_id
.name_offset
== UINT64_MAX
);
2588 void notif_thread_state_remove_trigger_ht_elem(
2589 struct notification_thread_state
*state
,
2590 struct lttng_trigger_ht_element
*trigger_ht_element
)
2593 assert(trigger_ht_element
);
2595 cds_lfht_del(state
->triggers_ht
, &trigger_ht_element
->node
);
2596 cds_lfht_del(state
->triggers_by_name_uid_ht
, &trigger_ht_element
->node_by_name_uid
);
2600 enum lttng_error_code
setup_tracer_notifier(
2601 struct notification_thread_state
*state
,
2602 struct lttng_trigger
*trigger
)
2604 enum lttng_error_code ret
;
2605 enum event_notifier_error_accounting_status error_accounting_status
;
2606 struct cds_lfht_node
*node
;
2607 uint64_t error_counter_index
= 0;
2608 struct lttng_condition
*condition
= lttng_trigger_get_condition(trigger
);
2609 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
= NULL
;
2611 trigger_tokens_ht_element
= zmalloc(sizeof(*trigger_tokens_ht_element
));
2612 if (!trigger_tokens_ht_element
) {
2613 ret
= LTTNG_ERR_NOMEM
;
2617 /* Add trigger token to the trigger_tokens_ht. */
2618 cds_lfht_node_init(&trigger_tokens_ht_element
->node
);
2619 trigger_tokens_ht_element
->token
= LTTNG_OPTIONAL_GET(trigger
->tracer_token
);
2620 trigger_tokens_ht_element
->trigger
= trigger
;
2622 node
= cds_lfht_add_unique(state
->trigger_tokens_ht
,
2623 hash_key_u64(&trigger_tokens_ht_element
->token
, lttng_ht_seed
),
2624 match_trigger_token
,
2625 &trigger_tokens_ht_element
->token
,
2626 &trigger_tokens_ht_element
->node
);
2627 if (node
!= &trigger_tokens_ht_element
->node
) {
2628 ret
= LTTNG_ERR_TRIGGER_EXISTS
;
2629 goto error_free_ht_element
;
2632 error_accounting_status
= event_notifier_error_accounting_register_event_notifier(
2633 trigger
, &error_counter_index
);
2634 if (error_accounting_status
!= EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK
) {
2635 if (error_accounting_status
== EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE
) {
2636 DBG("Trigger list error accounting counter full.");
2637 ret
= LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING_FULL
;
2639 ERR("Error registering trigger for error accounting");
2640 ret
= LTTNG_ERR_EVENT_NOTIFIER_REGISTRATION
;
2643 goto error_remove_ht_element
;
2646 lttng_condition_event_rule_matches_set_error_counter_index(
2647 condition
, error_counter_index
);
2652 error_remove_ht_element
:
2653 cds_lfht_del(state
->trigger_tokens_ht
, &trigger_tokens_ht_element
->node
);
2654 error_free_ht_element
:
2655 free(trigger_tokens_ht_element
);
2661 * FIXME A client's credentials are not checked when registering a trigger.
2663 * The effects of this are benign since:
2664 * - The client will succeed in registering the trigger, as it is valid,
2665 * - The trigger will, internally, be bound to the channel/session,
2666 * - The notifications will not be sent since the client's credentials
2667 * are checked against the channel at that moment.
2669 * If this function returns a non-zero value, it means something is
2670 * fundamentally broken and the whole subsystem/thread will be torn down.
2672 * If a non-fatal error occurs, just set the cmd_result to the appropriate
2676 int handle_notification_thread_command_register_trigger(
2677 struct notification_thread_state
*state
,
2678 struct lttng_trigger
*trigger
,
2679 bool is_trigger_anonymous
,
2680 enum lttng_error_code
*cmd_result
)
2683 struct lttng_condition
*condition
;
2684 struct notification_client_list
*client_list
= NULL
;
2685 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
2686 struct cds_lfht_node
*node
;
2687 const char* trigger_name
;
2688 bool free_trigger
= true;
2689 struct lttng_evaluation
*evaluation
= NULL
;
2690 struct lttng_credentials object_creds
;
2693 enum action_executor_status executor_status
;
2694 const uint64_t trigger_tracer_token
=
2695 state
->trigger_id
.next_tracer_token
++;
2699 /* Set the trigger's tracer token. */
2700 lttng_trigger_set_tracer_token(trigger
, trigger_tracer_token
);
2702 if (!is_trigger_anonymous
) {
2703 if (lttng_trigger_get_name(trigger
, &trigger_name
) ==
2704 LTTNG_TRIGGER_STATUS_UNSET
) {
2705 const enum lttng_error_code ret_code
=
2706 generate_trigger_name(state
, trigger
,
2709 if (ret_code
!= LTTNG_OK
) {
2712 *cmd_result
= ret_code
;
2715 } else if (trigger_name_taken(state
, trigger
)) {
2716 /* Not a fatal error. */
2717 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2722 trigger_name
= "(anonymous)";
2725 condition
= lttng_trigger_get_condition(trigger
);
2728 /* Some conditions require tracers to implement a minimal ABI version. */
2729 if (!condition_is_supported(condition
)) {
2730 *cmd_result
= LTTNG_ERR_NOT_SUPPORTED
;
2734 trigger_ht_element
= zmalloc(sizeof(*trigger_ht_element
));
2735 if (!trigger_ht_element
) {
2740 /* Add trigger to the trigger_ht. */
2741 cds_lfht_node_init(&trigger_ht_element
->node
);
2742 cds_lfht_node_init(&trigger_ht_element
->node_by_name_uid
);
2743 trigger_ht_element
->trigger
= trigger
;
2745 node
= cds_lfht_add_unique(state
->triggers_ht
,
2746 lttng_condition_hash(condition
),
2749 &trigger_ht_element
->node
);
2750 if (node
!= &trigger_ht_element
->node
) {
2751 /* Not a fatal error, simply report it to the client. */
2752 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2753 goto error_free_ht_element
;
2756 node
= cds_lfht_add_unique(state
->triggers_by_name_uid_ht
,
2757 hash_trigger_by_name_uid(trigger
),
2758 match_trigger_by_name_uid
,
2760 &trigger_ht_element
->node_by_name_uid
);
2761 if (node
!= &trigger_ht_element
->node_by_name_uid
) {
2762 /* Internal error: add to triggers_ht should have failed. */
2764 goto error_free_ht_element
;
2767 /* From this point consider the trigger registered. */
2768 lttng_trigger_set_as_registered(trigger
);
2771 * Some triggers might need a tracer notifier depending on its
2772 * condition and actions.
2774 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
2775 enum lttng_error_code error_code
;
2777 error_code
= setup_tracer_notifier(state
, trigger
);
2778 if (error_code
!= LTTNG_OK
) {
2779 notif_thread_state_remove_trigger_ht_elem(state
,
2780 trigger_ht_element
);
2781 if (error_code
== LTTNG_ERR_NOMEM
) {
2784 *cmd_result
= error_code
;
2788 goto error_free_ht_element
;
2793 * The rest only applies to triggers that have a "notify" action.
2794 * It is not skipped as this is the only action type currently
2797 if (is_trigger_action_notify(trigger
)) {
2799 * Find or create the client list of this condition. It may
2800 * already be present if another trigger is already registered
2801 * with the same condition.
2803 client_list
= get_client_list_from_condition(state
, condition
);
2806 * No client list for this condition yet. We create new
2807 * one and build it up.
2809 client_list
= notification_client_list_create(state
, condition
);
2811 ERR("Error creating notification client list for trigger %s", trigger
->name
);
2813 goto error_free_ht_element
;
2817 CDS_INIT_LIST_HEAD(&trigger_ht_element
->client_list_trigger_node
);
2819 pthread_mutex_lock(&client_list
->lock
);
2820 cds_list_add(&trigger_ht_element
->client_list_trigger_node
, &client_list
->triggers_list
);
2821 pthread_mutex_unlock(&client_list
->lock
);
2825 * Ownership of the trigger and of its wrapper was transfered to
2826 * the triggers_ht. Same for token ht element if necessary.
2828 trigger_ht_element
= NULL
;
2829 free_trigger
= false;
2831 switch (get_condition_binding_object(condition
)) {
2832 case LTTNG_OBJECT_TYPE_SESSION
:
2833 /* Add the trigger to the list if it matches a known session. */
2834 ret
= bind_trigger_to_matching_session(trigger
, state
);
2836 goto error_free_ht_element
;
2839 case LTTNG_OBJECT_TYPE_CHANNEL
:
2841 * Add the trigger to list of triggers bound to the channels
2844 ret
= bind_trigger_to_matching_channels(trigger
, state
);
2846 goto error_free_ht_element
;
2849 case LTTNG_OBJECT_TYPE_NONE
:
2852 ERR("Unknown object type on which to bind a newly registered trigger was encountered");
2854 goto error_free_ht_element
;
2858 * The new trigger's condition must be evaluated against the current
2861 * In the case of `notify` action, nothing preventing clients from
2862 * subscribing to a condition before the corresponding trigger is
2863 * registered, we have to evaluate this new condition right away.
2865 * At some point, we were waiting for the next "evaluation" (e.g. on
2866 * reception of a channel sample) to evaluate this new condition, but
2869 * The reason it was broken is that waiting for the next sample
2870 * does not allow us to properly handle transitions for edge-triggered
2873 * Consider this example: when we handle a new channel sample, we
2874 * evaluate each conditions twice: once with the previous state, and
2875 * again with the newest state. We then use those two results to
2876 * determine whether a state change happened: a condition was false and
2877 * became true. If a state change happened, we have to notify clients.
2879 * Now, if a client subscribes to a given notification and registers
2880 * a trigger *after* that subscription, we have to make sure the
2881 * condition is evaluated at this point while considering only the
2882 * current state. Otherwise, the next evaluation cycle may only see
2883 * that the evaluations remain the same (true for samples n-1 and n) and
2884 * the client will never know that the condition has been met.
2886 switch (get_condition_binding_object(condition
)) {
2887 case LTTNG_OBJECT_TYPE_SESSION
:
2888 ret
= evaluate_session_condition_for_client(condition
, state
,
2889 &evaluation
, &object_uid
,
2891 LTTNG_OPTIONAL_SET(&object_creds
.uid
, object_uid
);
2892 LTTNG_OPTIONAL_SET(&object_creds
.gid
, object_gid
);
2894 case LTTNG_OBJECT_TYPE_CHANNEL
:
2895 ret
= evaluate_channel_condition_for_client(condition
, state
,
2896 &evaluation
, &object_uid
,
2898 LTTNG_OPTIONAL_SET(&object_creds
.uid
, object_uid
);
2899 LTTNG_OPTIONAL_SET(&object_creds
.gid
, object_gid
);
2901 case LTTNG_OBJECT_TYPE_NONE
:
2904 case LTTNG_OBJECT_TYPE_UNKNOWN
:
2912 goto error_free_ht_element
;
2915 DBG("Newly registered trigger's condition evaluated to %s",
2916 evaluation
? "true" : "false");
2918 /* Evaluation yielded nothing. Normal exit. */
2924 * Ownership of `evaluation` transferred to the action executor
2925 * no matter the result.
2927 executor_status
= action_executor_enqueue_trigger(state
->executor
,
2928 trigger
, evaluation
, &object_creds
, client_list
);
2930 switch (executor_status
) {
2931 case ACTION_EXECUTOR_STATUS_OK
:
2933 case ACTION_EXECUTOR_STATUS_ERROR
:
2934 case ACTION_EXECUTOR_STATUS_INVALID
:
2936 * TODO Add trigger identification (name/id) when
2937 * it is added to the API.
2939 ERR("Fatal error occurred while enqueuing action associated to newly registered trigger");
2941 goto error_free_ht_element
;
2942 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
2944 * TODO Add trigger identification (name/id) when
2945 * it is added to the API.
2947 * Not a fatal error.
2949 WARN("No space left when enqueuing action associated to newly registered trigger");
2957 *cmd_result
= LTTNG_OK
;
2958 DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64
,
2959 trigger_name
, trigger_tracer_token
);
2962 error_free_ht_element
:
2963 if (trigger_ht_element
) {
2964 /* Delayed removal due to RCU constraint on delete. */
2965 call_rcu(&trigger_ht_element
->rcu_node
,
2966 free_lttng_trigger_ht_element_rcu
);
2971 * Other objects might have a reference to the trigger, mark it
2974 lttng_trigger_set_as_unregistered(trigger
);
2975 lttng_trigger_destroy(trigger
);
2983 void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
)
2985 free(caa_container_of(node
, struct lttng_trigger_ht_element
,
2990 void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head
*node
)
2992 free(caa_container_of(node
, struct notification_trigger_tokens_ht_element
,
2997 void teardown_tracer_notifier(struct notification_thread_state
*state
,
2998 const struct lttng_trigger
*trigger
)
3000 struct cds_lfht_iter iter
;
3001 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
;
3003 cds_lfht_for_each_entry(state
->trigger_tokens_ht
, &iter
,
3004 trigger_tokens_ht_element
, node
) {
3006 if (!lttng_trigger_is_equal(trigger
,
3007 trigger_tokens_ht_element
->trigger
)) {
3011 event_notifier_error_accounting_unregister_event_notifier(
3012 trigger_tokens_ht_element
->trigger
);
3014 /* TODO talk to all app and remove it */
3015 DBG("Removed trigger from tokens_ht");
3016 cds_lfht_del(state
->trigger_tokens_ht
,
3017 &trigger_tokens_ht_element
->node
);
3019 call_rcu(&trigger_tokens_ht_element
->rcu_node
,
3020 free_notification_trigger_tokens_ht_element_rcu
);
3027 int handle_notification_thread_command_unregister_trigger(
3028 struct notification_thread_state
*state
,
3029 const struct lttng_trigger
*trigger
,
3030 enum lttng_error_code
*_cmd_reply
)
3032 struct cds_lfht_iter iter
;
3033 struct cds_lfht_node
*triggers_ht_node
;
3034 struct lttng_channel_trigger_list
*trigger_list
;
3035 struct notification_client_list
*client_list
;
3036 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
3037 const struct lttng_condition
*condition
= lttng_trigger_get_const_condition(
3039 enum lttng_error_code cmd_reply
;
3043 cds_lfht_lookup(state
->triggers_ht
,
3044 lttng_condition_hash(condition
),
3048 triggers_ht_node
= cds_lfht_iter_get_node(&iter
);
3049 if (!triggers_ht_node
) {
3050 cmd_reply
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
3053 cmd_reply
= LTTNG_OK
;
3056 trigger_ht_element
= caa_container_of(triggers_ht_node
,
3057 struct lttng_trigger_ht_element
, node
);
3059 /* Remove trigger from channel_triggers_ht. */
3060 cds_lfht_for_each_entry(state
->channel_triggers_ht
, &iter
, trigger_list
,
3061 channel_triggers_ht_node
) {
3062 struct lttng_trigger_list_element
*trigger_element
, *tmp
;
3064 cds_list_for_each_entry_safe(trigger_element
, tmp
,
3065 &trigger_list
->list
, node
) {
3066 if (!lttng_trigger_is_equal(trigger
, trigger_element
->trigger
)) {
3070 DBG("Removed trigger from channel_triggers_ht");
3071 cds_list_del(&trigger_element
->node
);
3072 /* A trigger can only appear once per channel */
3077 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
3078 teardown_tracer_notifier(state
, trigger
);
3081 if (is_trigger_action_notify(trigger
)) {
3083 * Remove and release the client list from
3084 * notification_trigger_clients_ht.
3086 client_list
= get_client_list_from_condition(state
, condition
);
3087 assert(client_list
);
3089 pthread_mutex_lock(&client_list
->lock
);
3090 cds_list_del(&trigger_ht_element
->client_list_trigger_node
);
3091 pthread_mutex_unlock(&client_list
->lock
);
3093 /* Put new reference and the hashtable's reference. */
3094 notification_client_list_put(client_list
);
3095 notification_client_list_put(client_list
);
3099 /* Remove trigger from triggers_ht. */
3100 notif_thread_state_remove_trigger_ht_elem(state
, trigger_ht_element
);
3102 /* Release the ownership of the trigger. */
3103 lttng_trigger_destroy(trigger_ht_element
->trigger
);
3104 call_rcu(&trigger_ht_element
->rcu_node
, free_lttng_trigger_ht_element_rcu
);
3108 *_cmd_reply
= cmd_reply
;
3114 int pop_cmd_queue(struct notification_thread_handle
*handle
,
3115 struct notification_thread_command
**cmd
)
3120 pthread_mutex_lock(&handle
->cmd_queue
.lock
);
3121 ret
= lttng_read(handle
->cmd_queue
.event_fd
, &counter
, sizeof(counter
));
3122 if (ret
!= sizeof(counter
)) {
3127 /* Simulate behaviour of EFD_SEMAPHORE for older kernels. */
3130 ret
= lttng_write(handle
->cmd_queue
.event_fd
, &counter
,
3132 if (ret
!= sizeof(counter
)) {
3133 PERROR("Failed to write back to event_fd for EFD_SEMAPHORE emulation");
3139 *cmd
= cds_list_first_entry(&handle
->cmd_queue
.list
,
3140 struct notification_thread_command
, cmd_list_node
);
3141 cds_list_del(&((*cmd
)->cmd_list_node
));
3145 pthread_mutex_unlock(&handle
->cmd_queue
.lock
);
3149 /* Returns 0 on success, 1 on exit requested, negative value on error. */
3150 int handle_notification_thread_command(
3151 struct notification_thread_handle
*handle
,
3152 struct notification_thread_state
*state
)
3155 struct notification_thread_command
*cmd
;
3157 ret
= pop_cmd_queue(handle
, &cmd
);
3162 DBG("Received `%s` command",
3163 notification_command_type_str(cmd
->type
));
3164 switch (cmd
->type
) {
3165 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
3166 ret
= handle_notification_thread_command_register_trigger(state
,
3167 cmd
->parameters
.register_trigger
.trigger
,
3168 cmd
->parameters
.register_trigger
.is_trigger_anonymous
,
3171 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
3172 ret
= handle_notification_thread_command_unregister_trigger(
3174 cmd
->parameters
.unregister_trigger
.trigger
,
3177 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
3178 ret
= handle_notification_thread_command_add_channel(
3180 cmd
->parameters
.add_channel
.session
.name
,
3181 cmd
->parameters
.add_channel
.session
.uid
,
3182 cmd
->parameters
.add_channel
.session
.gid
,
3183 cmd
->parameters
.add_channel
.channel
.name
,
3184 cmd
->parameters
.add_channel
.channel
.domain
,
3185 cmd
->parameters
.add_channel
.channel
.key
,
3186 cmd
->parameters
.add_channel
.channel
.capacity
,
3189 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
3190 ret
= handle_notification_thread_command_remove_channel(
3191 state
, cmd
->parameters
.remove_channel
.key
,
3192 cmd
->parameters
.remove_channel
.domain
,
3195 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
3196 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
3197 ret
= handle_notification_thread_command_session_rotation(
3200 cmd
->parameters
.session_rotation
.session_name
,
3201 cmd
->parameters
.session_rotation
.uid
,
3202 cmd
->parameters
.session_rotation
.gid
,
3203 cmd
->parameters
.session_rotation
.trace_archive_chunk_id
,
3204 cmd
->parameters
.session_rotation
.location
,
3207 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
3208 ret
= handle_notification_thread_command_add_tracer_event_source(
3210 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3211 cmd
->parameters
.tracer_event_source
.domain
,
3214 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
3215 ret
= handle_notification_thread_command_remove_tracer_event_source(
3217 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3220 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
3222 struct lttng_triggers
*triggers
= NULL
;
3224 ret
= handle_notification_thread_command_list_triggers(
3227 cmd
->parameters
.list_triggers
.uid
,
3230 cmd
->reply
.list_triggers
.triggers
= triggers
;
3234 case NOTIFICATION_COMMAND_TYPE_QUIT
:
3235 cmd
->reply_code
= LTTNG_OK
;
3238 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
3240 struct lttng_trigger
*trigger
= NULL
;
3242 ret
= handle_notification_thread_command_get_trigger(state
,
3243 cmd
->parameters
.get_trigger
.trigger
, &trigger
,
3245 cmd
->reply
.get_trigger
.trigger
= trigger
;
3248 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
3250 const enum client_transmission_status client_status
=
3251 cmd
->parameters
.client_communication_update
3253 const notification_client_id client_id
=
3254 cmd
->parameters
.client_communication_update
.id
;
3255 struct notification_client
*client
;
3258 client
= get_client_from_id(client_id
, state
);
3262 * Client error was probably already picked-up by the
3263 * notification thread or it has disconnected
3264 * gracefully while this command was queued.
3266 DBG("Failed to find notification client to update communication status, client id = %" PRIu64
,
3270 ret
= client_handle_transmission_status(
3271 client
, client_status
, state
);
3277 ERR("Unknown internal command received");
3285 if (cmd
->is_async
) {
3289 lttng_waiter_wake_up(&cmd
->reply_waiter
);
3293 /* Wake-up and return a fatal error to the calling thread. */
3294 lttng_waiter_wake_up(&cmd
->reply_waiter
);
3295 cmd
->reply_code
= LTTNG_ERR_FATAL
;
3297 /* Indicate a fatal error to the caller. */
3302 int socket_set_non_blocking(int socket
)
3306 /* Set the pipe as non-blocking. */
3307 ret
= fcntl(socket
, F_GETFL
, 0);
3309 PERROR("fcntl get socket flags");
3314 ret
= fcntl(socket
, F_SETFL
, flags
| O_NONBLOCK
);
3316 PERROR("fcntl set O_NONBLOCK socket flag");
3319 DBG("Client socket (fd = %i) set as non-blocking", socket
);
3325 int client_reset_inbound_state(struct notification_client
*client
)
3330 lttng_payload_clear(&client
->communication
.inbound
.payload
);
3332 client
->communication
.inbound
.bytes_to_receive
=
3333 sizeof(struct lttng_notification_channel_message
);
3334 client
->communication
.inbound
.msg_type
=
3335 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
;
3336 LTTNG_SOCK_SET_UID_CRED(&client
->communication
.inbound
.creds
, -1);
3337 LTTNG_SOCK_SET_GID_CRED(&client
->communication
.inbound
.creds
, -1);
3338 ret
= lttng_dynamic_buffer_set_size(
3339 &client
->communication
.inbound
.payload
.buffer
,
3340 client
->communication
.inbound
.bytes_to_receive
);
3345 int handle_notification_thread_client_connect(
3346 struct notification_thread_state
*state
)
3349 struct notification_client
*client
;
3351 DBG("Handling new notification channel client connection");
3353 client
= zmalloc(sizeof(*client
));
3360 pthread_mutex_init(&client
->lock
, NULL
);
3361 client
->id
= state
->next_notification_client_id
++;
3362 CDS_INIT_LIST_HEAD(&client
->condition_list
);
3363 lttng_payload_init(&client
->communication
.inbound
.payload
);
3364 lttng_payload_init(&client
->communication
.outbound
.payload
);
3365 client
->communication
.inbound
.expect_creds
= true;
3367 ret
= client_reset_inbound_state(client
);
3369 ERR("Failed to reset client communication's inbound state");
3374 ret
= lttcomm_accept_unix_sock(state
->notification_channel_socket
);
3376 ERR("Failed to accept new notification channel client connection");
3381 client
->socket
= ret
;
3383 ret
= socket_set_non_blocking(client
->socket
);
3385 ERR("Failed to set new notification channel client connection socket as non-blocking");
3389 ret
= lttcomm_setsockopt_creds_unix_sock(client
->socket
);
3391 ERR("Failed to set socket options on new notification channel client socket");
3396 client
->communication
.current_poll_events
= CLIENT_POLL_EVENTS_IN
;
3397 ret
= lttng_poll_add(&state
->events
, client
->socket
,
3398 client
->communication
.current_poll_events
);
3400 ERR("Failed to add notification channel client socket to poll set");
3404 DBG("Added new notification channel client socket (%i) to poll set",
3408 cds_lfht_add(state
->client_socket_ht
,
3409 hash_client_socket(client
->socket
),
3410 &client
->client_socket_ht_node
);
3411 cds_lfht_add(state
->client_id_ht
,
3412 hash_client_id(client
->id
),
3413 &client
->client_id_ht_node
);
3419 notification_client_destroy(client
, state
);
3424 * RCU read-lock must be held by the caller.
3425 * Client lock must _not_ be held by the caller.
3428 int notification_thread_client_disconnect(
3429 struct notification_client
*client
,
3430 struct notification_thread_state
*state
)
3433 struct lttng_condition_list_element
*condition_list_element
, *tmp
;
3435 /* Acquire the client lock to disable its communication atomically. */
3436 pthread_mutex_lock(&client
->lock
);
3437 client
->communication
.active
= false;
3438 cds_lfht_del(state
->client_socket_ht
, &client
->client_socket_ht_node
);
3439 cds_lfht_del(state
->client_id_ht
, &client
->client_id_ht_node
);
3440 pthread_mutex_unlock(&client
->lock
);
3442 ret
= lttng_poll_del(&state
->events
, client
->socket
);
3444 ERR("Failed to remove client socket %d from poll set",
3448 /* Release all conditions to which the client was subscribed. */
3449 cds_list_for_each_entry_safe(condition_list_element
, tmp
,
3450 &client
->condition_list
, node
) {
3451 (void) notification_thread_client_unsubscribe(client
,
3452 condition_list_element
->condition
, state
, NULL
);
3456 * Client no longer accessible to other threads (through the
3459 notification_client_destroy(client
, state
);
3463 int handle_notification_thread_client_disconnect(
3464 int client_socket
, struct notification_thread_state
*state
)
3467 struct notification_client
*client
;
3470 DBG("Closing client connection (socket fd = %i)",
3472 client
= get_client_from_socket(client_socket
, state
);
3474 /* Internal state corruption, fatal error. */
3475 ERR("Unable to find client (socket fd = %i)",
3481 ret
= notification_thread_client_disconnect(client
, state
);
3487 int handle_notification_thread_client_disconnect_all(
3488 struct notification_thread_state
*state
)
3490 struct cds_lfht_iter iter
;
3491 struct notification_client
*client
;
3492 bool error_encoutered
= false;
3495 DBG("Closing all client connections");
3496 cds_lfht_for_each_entry(state
->client_socket_ht
, &iter
, client
,
3497 client_socket_ht_node
) {
3500 ret
= notification_thread_client_disconnect(
3503 error_encoutered
= true;
3507 return error_encoutered
? 1 : 0;
3510 int handle_notification_thread_trigger_unregister_all(
3511 struct notification_thread_state
*state
)
3513 bool error_occurred
= false;
3514 struct cds_lfht_iter iter
;
3515 struct lttng_trigger_ht_element
*trigger_ht_element
;
3518 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
3520 int ret
= handle_notification_thread_command_unregister_trigger(
3521 state
, trigger_ht_element
->trigger
, NULL
);
3523 error_occurred
= true;
3527 return error_occurred
? -1 : 0;
3531 bool client_has_outbound_data_left(
3532 const struct notification_client
*client
)
3534 const struct lttng_payload_view pv
= lttng_payload_view_from_payload(
3535 &client
->communication
.outbound
.payload
, 0, -1);
3536 const bool has_data
= pv
.buffer
.size
!= 0;
3537 const bool has_fds
= lttng_payload_view_get_fd_handle_count(&pv
);
3539 return has_data
|| has_fds
;
3543 int client_handle_transmission_status(
3544 struct notification_client
*client
,
3545 enum client_transmission_status transmission_status
,
3546 struct notification_thread_state
*state
)
3550 switch (transmission_status
) {
3551 case CLIENT_TRANSMISSION_STATUS_COMPLETE
:
3552 case CLIENT_TRANSMISSION_STATUS_QUEUED
:
3554 int current_poll_events
;
3555 int new_poll_events
;
3557 * We want to be notified whenever there is buffer space
3558 * available to send the rest of the payload if we are
3559 * waiting to send data to the client.
3561 * The state of the outbound queue being sampled here is
3563 * - it is okay to wake-up "for nothing" in case we see
3564 * that data is left, but another thread succeeds in
3565 * flushing it before us when handling the client "out"
3566 * event. We will simply stop monitoring that event the next
3567 * time it wakes us up and we see no data left to be sent,
3568 * - if another thread fails to flush the entire client
3569 * outgoing queue, it will issue a "communication update"
3570 * command and cause the client's (e)poll mask to be
3573 * The situation we seek to avoid would be to disable the
3574 * monitoring of "out" client events indefinitely when there is
3575 * data to be sent, which can't happen because of the
3576 * aforementioned "communication update" mechanism.
3578 pthread_mutex_lock(&client
->lock
);
3579 current_poll_events
= client
->communication
.current_poll_events
;
3580 new_poll_events
= client_has_outbound_data_left(client
) ?
3581 CLIENT_POLL_EVENTS_IN_OUT
:
3582 CLIENT_POLL_EVENTS_IN
;
3583 client
->communication
.current_poll_events
= new_poll_events
;
3584 pthread_mutex_unlock(&client
->lock
);
3586 /* Update the monitored event set only if it changed. */
3587 if (current_poll_events
!= new_poll_events
) {
3588 ret
= lttng_poll_mod(&state
->events
, client
->socket
,
3597 case CLIENT_TRANSMISSION_STATUS_FAIL
:
3598 ret
= notification_thread_client_disconnect(client
, state
);
3603 case CLIENT_TRANSMISSION_STATUS_ERROR
:
3613 /* Client lock must be acquired by caller. */
3615 enum client_transmission_status
client_flush_outgoing_queue(
3616 struct notification_client
*client
)
3619 size_t to_send_count
;
3620 enum client_transmission_status status
;
3621 struct lttng_payload_view pv
= lttng_payload_view_from_payload(
3622 &client
->communication
.outbound
.payload
, 0, -1);
3623 const int fds_to_send_count
=
3624 lttng_payload_view_get_fd_handle_count(&pv
);
3626 ASSERT_LOCKED(client
->lock
);
3628 if (!client
->communication
.active
) {
3629 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3633 if (pv
.buffer
.size
== 0) {
3635 * If both data and fds are equal to zero, we are in an invalid
3638 assert(fds_to_send_count
!= 0);
3643 to_send_count
= pv
.buffer
.size
;
3644 DBG("Flushing client (socket fd = %i) outgoing queue",
3647 ret
= lttcomm_send_unix_sock_non_block(client
->socket
,
3650 if ((ret
>= 0 && ret
< to_send_count
)) {
3651 DBG("Client (socket fd = %i) outgoing queue could not be completely flushed",
3653 to_send_count
-= max(ret
, 0);
3655 memmove(client
->communication
.outbound
.payload
.buffer
.data
,
3657 pv
.buffer
.size
- to_send_count
,
3659 ret
= lttng_dynamic_buffer_set_size(
3660 &client
->communication
.outbound
.payload
.buffer
,
3666 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3668 } else if (ret
< 0) {
3669 /* Generic error, disable the client's communication. */
3670 ERR("Failed to flush outgoing queue, disconnecting client (socket fd = %i)",
3672 client
->communication
.active
= false;
3673 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3677 * No error and flushed the queue completely.
3679 * The payload buffer size is used later to
3680 * check if there is notifications queued. So albeit that the
3681 * direct caller knows that the transmission is complete, we
3682 * need to set the buffer size to zero.
3684 ret
= lttng_dynamic_buffer_set_size(
3685 &client
->communication
.outbound
.payload
.buffer
, 0);
3692 /* No fds to send, transmission is complete. */
3693 if (fds_to_send_count
== 0) {
3694 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3698 ret
= lttcomm_send_payload_view_fds_unix_sock_non_block(
3699 client
->socket
, &pv
);
3701 /* Generic error, disable the client's communication. */
3702 ERR("Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)",
3704 client
->communication
.active
= false;
3705 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3707 } else if (ret
== 0) {
3708 /* Nothing could be sent. */
3709 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3711 /* Fd passing is an all or nothing kind of thing. */
3712 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3714 * The payload _fd_array count is used later to
3715 * check if there is notifications queued. So although the
3716 * direct caller knows that the transmission is complete, we
3717 * need to clear the _fd_array for the queuing check.
3719 lttng_dynamic_pointer_array_clear(
3720 &client
->communication
.outbound
.payload
3725 if (status
== CLIENT_TRANSMISSION_STATUS_COMPLETE
) {
3726 client
->communication
.outbound
.queued_command_reply
= false;
3727 client
->communication
.outbound
.dropped_notification
= false;
3728 lttng_payload_clear(&client
->communication
.outbound
.payload
);
3733 return CLIENT_TRANSMISSION_STATUS_ERROR
;
3736 /* Client lock must _not_ be held by the caller. */
3738 int client_send_command_reply(struct notification_client
*client
,
3739 struct notification_thread_state
*state
,
3740 enum lttng_notification_channel_status status
)
3743 struct lttng_notification_channel_command_reply reply
= {
3744 .status
= (int8_t) status
,
3746 struct lttng_notification_channel_message msg
= {
3747 .type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY
,
3748 .size
= sizeof(reply
),
3750 char buffer
[sizeof(msg
) + sizeof(reply
)];
3751 enum client_transmission_status transmission_status
;
3753 memcpy(buffer
, &msg
, sizeof(msg
));
3754 memcpy(buffer
+ sizeof(msg
), &reply
, sizeof(reply
));
3755 DBG("Send command reply (%i)", (int) status
);
3757 pthread_mutex_lock(&client
->lock
);
3758 if (client
->communication
.outbound
.queued_command_reply
) {
3759 /* Protocol error. */
3763 /* Enqueue buffer to outgoing queue and flush it. */
3764 ret
= lttng_dynamic_buffer_append(
3765 &client
->communication
.outbound
.payload
.buffer
,
3766 buffer
, sizeof(buffer
));
3771 transmission_status
= client_flush_outgoing_queue(client
);
3773 if (client_has_outbound_data_left(client
)) {
3774 /* Queue could not be emptied. */
3775 client
->communication
.outbound
.queued_command_reply
= true;
3778 pthread_mutex_unlock(&client
->lock
);
3779 ret
= client_handle_transmission_status(
3780 client
, transmission_status
, state
);
3787 pthread_mutex_unlock(&client
->lock
);
3793 int client_handle_message_unknown(struct notification_client
*client
,
3794 struct notification_thread_state
*state
)
3798 * Receiving message header. The function will be called again
3799 * once the rest of the message as been received and can be
3802 const struct lttng_notification_channel_message
*msg
;
3804 assert(sizeof(*msg
) == client
->communication
.inbound
.payload
.buffer
.size
);
3805 msg
= (const struct lttng_notification_channel_message
*)
3806 client
->communication
.inbound
.payload
.buffer
.data
;
3808 if (msg
->size
== 0 ||
3809 msg
->size
> DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE
) {
3810 ERR("Invalid notification channel message: length = %u",
3816 switch (msg
->type
) {
3817 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
3818 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
3819 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
3823 ERR("Invalid notification channel message: unexpected message type");
3827 client
->communication
.inbound
.bytes_to_receive
= msg
->size
;
3828 client
->communication
.inbound
.fds_to_receive
= msg
->fds
;
3829 client
->communication
.inbound
.msg_type
=
3830 (enum lttng_notification_channel_message_type
) msg
->type
;
3831 ret
= lttng_dynamic_buffer_set_size(
3832 &client
->communication
.inbound
.payload
.buffer
, msg
->size
);
3834 /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */
3841 int client_handle_message_handshake(struct notification_client
*client
,
3842 struct notification_thread_state
*state
)
3845 struct lttng_notification_channel_command_handshake
*handshake_client
;
3846 const struct lttng_notification_channel_command_handshake handshake_reply
= {
3847 .major
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
,
3848 .minor
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR
,
3850 const struct lttng_notification_channel_message msg_header
= {
3851 .type
= LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
,
3852 .size
= sizeof(handshake_reply
),
3854 enum lttng_notification_channel_status status
=
3855 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
3856 char send_buffer
[sizeof(msg_header
) + sizeof(handshake_reply
)];
3858 memcpy(send_buffer
, &msg_header
, sizeof(msg_header
));
3859 memcpy(send_buffer
+ sizeof(msg_header
), &handshake_reply
,
3860 sizeof(handshake_reply
));
3863 (struct lttng_notification_channel_command_handshake
*)
3864 client
->communication
.inbound
.payload
.buffer
3866 client
->major
= handshake_client
->major
;
3867 client
->minor
= handshake_client
->minor
;
3868 if (!client
->communication
.inbound
.creds_received
) {
3869 ERR("No credentials received from client");
3874 client
->uid
= LTTNG_SOCK_GET_UID_CRED(
3875 &client
->communication
.inbound
.creds
);
3876 client
->gid
= LTTNG_SOCK_GET_GID_CRED(
3877 &client
->communication
.inbound
.creds
);
3878 client
->is_sessiond
= LTTNG_SOCK_GET_PID_CRED(&client
->communication
.inbound
.creds
) == getpid();
3879 DBG("Received handshake from client: uid = %u, gid = %u, protocol version = %i.%i, client is sessiond = %s",
3880 client
->uid
, client
->gid
, (int) client
->major
,
3881 (int) client
->minor
,
3882 client
->is_sessiond
? "true" : "false");
3884 if (handshake_client
->major
!=
3885 LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
) {
3886 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION
;
3889 pthread_mutex_lock(&client
->lock
);
3890 /* Outgoing queue will be flushed when the command reply is sent. */
3891 ret
= lttng_dynamic_buffer_append(
3892 &client
->communication
.outbound
.payload
.buffer
, send_buffer
,
3893 sizeof(send_buffer
));
3895 ERR("Failed to send protocol version to notification channel client");
3899 client
->validated
= true;
3900 client
->communication
.active
= true;
3901 pthread_mutex_unlock(&client
->lock
);
3903 /* Set reception state to receive the next message header. */
3904 ret
= client_reset_inbound_state(client
);
3906 ERR("Failed to reset client communication's inbound state");
3910 /* Flushes the outgoing queue. */
3911 ret
= client_send_command_reply(client
, state
, status
);
3913 ERR("Failed to send reply to notification channel client");
3919 pthread_mutex_unlock(&client
->lock
);
3925 int client_handle_message_subscription(
3926 struct notification_client
*client
,
3927 enum lttng_notification_channel_message_type msg_type
,
3928 struct notification_thread_state
*state
)
3931 struct lttng_condition
*condition
;
3932 enum lttng_notification_channel_status status
=
3933 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
3934 struct lttng_payload_view condition_view
=
3935 lttng_payload_view_from_payload(
3936 &client
->communication
.inbound
.payload
,
3938 size_t expected_condition_size
;
3941 * No need to lock client to sample the inbound state as the only
3942 * other thread accessing clients (action executor) only uses the
3945 expected_condition_size
= client
->communication
.inbound
.payload
.buffer
.size
;
3946 ret
= lttng_condition_create_from_payload(&condition_view
, &condition
);
3947 if (ret
!= expected_condition_size
) {
3948 ERR("Malformed condition received from client");
3952 /* Ownership of condition is always transferred. */
3953 if (msg_type
== LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
) {
3954 ret
= notification_thread_client_subscribe(
3955 client
, condition
, state
, &status
);
3957 ret
= notification_thread_client_unsubscribe(
3958 client
, condition
, state
, &status
);
3965 /* Set reception state to receive the next message header. */
3966 ret
= client_reset_inbound_state(client
);
3968 ERR("Failed to reset client communication's inbound state");
3972 ret
= client_send_command_reply(client
, state
, status
);
3974 ERR("Failed to send reply to notification channel client");
3983 int client_dispatch_message(struct notification_client
*client
,
3984 struct notification_thread_state
*state
)
3988 if (client
->communication
.inbound
.msg_type
!=
3989 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
&&
3990 client
->communication
.inbound
.msg_type
!=
3991 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
&&
3992 !client
->validated
) {
3993 WARN("client attempted a command before handshake");
3998 switch (client
->communication
.inbound
.msg_type
) {
3999 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
:
4001 ret
= client_handle_message_unknown(client
, state
);
4004 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
4006 ret
= client_handle_message_handshake(client
, state
);
4009 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
4010 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
4012 ret
= client_handle_message_subscription(client
,
4013 client
->communication
.inbound
.msg_type
, state
);
4023 /* Incoming data from client. */
4024 int handle_notification_thread_client_in(
4025 struct notification_thread_state
*state
, int socket
)
4028 struct notification_client
*client
;
4033 client
= get_client_from_socket(socket
, state
);
4035 /* Internal error, abort. */
4040 if (client
->communication
.inbound
.bytes_to_receive
== 0 &&
4041 client
->communication
.inbound
.fds_to_receive
!= 0) {
4042 /* Only FDs left to receive. */
4046 offset
= client
->communication
.inbound
.payload
.buffer
.size
-
4047 client
->communication
.inbound
.bytes_to_receive
;
4048 if (client
->communication
.inbound
.expect_creds
) {
4049 recv_ret
= lttcomm_recv_creds_unix_sock(socket
,
4050 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4051 client
->communication
.inbound
.bytes_to_receive
,
4052 &client
->communication
.inbound
.creds
);
4054 client
->communication
.inbound
.expect_creds
= false;
4055 client
->communication
.inbound
.creds_received
= true;
4058 recv_ret
= lttcomm_recv_unix_sock_non_block(socket
,
4059 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4060 client
->communication
.inbound
.bytes_to_receive
);
4062 if (recv_ret
>= 0) {
4063 client
->communication
.inbound
.bytes_to_receive
-= recv_ret
;
4065 goto error_disconnect_client
;
4068 if (client
->communication
.inbound
.bytes_to_receive
!= 0) {
4069 /* Message incomplete wait for more data. */
4075 assert(client
->communication
.inbound
.bytes_to_receive
== 0);
4078 if (client
->communication
.inbound
.fds_to_receive
!= 0) {
4079 ret
= lttcomm_recv_payload_fds_unix_sock_non_block(
4081 client
->communication
.inbound
.fds_to_receive
,
4082 &client
->communication
.inbound
.payload
);
4085 * Fds received. non blocking fds passing is all
4088 ssize_t expected_size
;
4090 expected_size
= sizeof(int) *
4091 client
->communication
.inbound
4093 assert(ret
== expected_size
);
4094 client
->communication
.inbound
.fds_to_receive
= 0;
4095 } else if (ret
== 0) {
4096 /* Received nothing. */
4100 goto error_disconnect_client
;
4104 /* At this point the message is complete.*/
4105 assert(client
->communication
.inbound
.bytes_to_receive
== 0 &&
4106 client
->communication
.inbound
.fds_to_receive
== 0);
4107 ret
= client_dispatch_message(client
, state
);
4110 * Only returns an error if this client must be
4113 goto error_disconnect_client
;
4120 error_disconnect_client
:
4121 ret
= notification_thread_client_disconnect(client
, state
);
4125 /* Client ready to receive outgoing data. */
4126 int handle_notification_thread_client_out(
4127 struct notification_thread_state
*state
, int socket
)
4130 struct notification_client
*client
;
4131 enum client_transmission_status transmission_status
;
4134 client
= get_client_from_socket(socket
, state
);
4136 /* Internal error, abort. */
4141 pthread_mutex_lock(&client
->lock
);
4142 if (!client_has_outbound_data_left(client
)) {
4144 * A client "out" event can be received when no payload is left
4145 * to send under some circumstances.
4147 * Many threads can flush a client's outgoing queue and, if they
4148 * had to queue their message (socket was full), will use the
4149 * "communication update" command to signal the (e)poll thread
4150 * to monitor for space being made available in the socket.
4152 * Commands are sent over an internal pipe serviced by the same
4153 * thread as the client sockets.
4155 * When space is made available in the socket, there is a race
4156 * between the (e)poll thread and the other threads that may
4157 * wish to use the client's socket to flush its outgoing queue.
4159 * A non-(e)poll thread may attempt (and succeed) in flushing
4160 * the queue before the (e)poll thread gets a chance to service
4161 * the client's "out" event.
4163 * In this situation, the (e)poll thread processing the client
4164 * out event will see an empty payload: there is nothing to do
4165 * except unsubscribing (e)poll "out" events.
4167 * Note that this thread is the (e)poll thread so it can modify
4168 * the (e)poll mask directly without using a communication
4169 * update command. Other threads that flush the outgoing queue
4170 * will use the "communication update" command to wake up this
4171 * thread and force it to monitor "out" events.
4173 * When other threads succeed in emptying the outgoing queue,
4174 * they don't need to update the (e)poll mask: if the "out"
4175 * event is monitored, it will fire once and the (e)poll
4176 * thread will reach this condition, causing the event to
4177 * stop being monitored.
4179 transmission_status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
4181 transmission_status
= client_flush_outgoing_queue(client
);
4183 pthread_mutex_unlock(&client
->lock
);
4185 ret
= client_handle_transmission_status(
4186 client
, transmission_status
, state
);
4196 bool evaluate_buffer_usage_condition(const struct lttng_condition
*condition
,
4197 const struct channel_state_sample
*sample
,
4198 uint64_t buffer_capacity
)
4200 bool result
= false;
4202 enum lttng_condition_type condition_type
;
4203 const struct lttng_condition_buffer_usage
*use_condition
= container_of(
4204 condition
, struct lttng_condition_buffer_usage
,
4207 if (use_condition
->threshold_bytes
.set
) {
4208 threshold
= use_condition
->threshold_bytes
.value
;
4211 * Threshold was expressed as a ratio.
4213 * TODO the threshold (in bytes) of conditions expressed
4214 * as a ratio of total buffer size could be cached to
4215 * forego this double-multiplication or it could be performed
4216 * as fixed-point math.
4218 * Note that caching should accommodates the case where the
4219 * condition applies to multiple channels (i.e. don't assume
4220 * that all channels matching my_chann* have the same size...)
4222 threshold
= (uint64_t) (use_condition
->threshold_ratio
.value
*
4223 (double) buffer_capacity
);
4226 condition_type
= lttng_condition_get_type(condition
);
4227 if (condition_type
== LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
) {
4228 DBG("Low buffer usage condition being evaluated: threshold = %" PRIu64
", highest usage = %" PRIu64
,
4229 threshold
, sample
->highest_usage
);
4232 * The low condition should only be triggered once _all_ of the
4233 * streams in a channel have gone below the "low" threshold.
4235 if (sample
->highest_usage
<= threshold
) {
4239 DBG("High buffer usage condition being evaluated: threshold = %" PRIu64
", highest usage = %" PRIu64
,
4240 threshold
, sample
->highest_usage
);
4243 * For high buffer usage scenarios, we want to trigger whenever
4244 * _any_ of the streams has reached the "high" threshold.
4246 if (sample
->highest_usage
>= threshold
) {
4255 bool evaluate_session_consumed_size_condition(
4256 const struct lttng_condition
*condition
,
4257 uint64_t session_consumed_size
)
4260 const struct lttng_condition_session_consumed_size
*size_condition
=
4261 container_of(condition
,
4262 struct lttng_condition_session_consumed_size
,
4265 threshold
= size_condition
->consumed_threshold_bytes
.value
;
4266 DBG("Session consumed size condition being evaluated: threshold = %" PRIu64
", current size = %" PRIu64
,
4267 threshold
, session_consumed_size
);
4268 return session_consumed_size
>= threshold
;
4272 int evaluate_buffer_condition(const struct lttng_condition
*condition
,
4273 struct lttng_evaluation
**evaluation
,
4274 const struct notification_thread_state
*state
,
4275 const struct channel_state_sample
*previous_sample
,
4276 const struct channel_state_sample
*latest_sample
,
4277 uint64_t previous_session_consumed_total
,
4278 uint64_t latest_session_consumed_total
,
4279 struct channel_info
*channel_info
)
4282 enum lttng_condition_type condition_type
;
4283 const bool previous_sample_available
= !!previous_sample
;
4284 bool previous_sample_result
= false;
4285 bool latest_sample_result
;
4287 condition_type
= lttng_condition_get_type(condition
);
4289 switch (condition_type
) {
4290 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4291 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4292 if (caa_likely(previous_sample_available
)) {
4293 previous_sample_result
=
4294 evaluate_buffer_usage_condition(condition
,
4295 previous_sample
, channel_info
->capacity
);
4297 latest_sample_result
= evaluate_buffer_usage_condition(
4298 condition
, latest_sample
,
4299 channel_info
->capacity
);
4301 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
4302 if (caa_likely(previous_sample_available
)) {
4303 previous_sample_result
=
4304 evaluate_session_consumed_size_condition(
4306 previous_session_consumed_total
);
4308 latest_sample_result
=
4309 evaluate_session_consumed_size_condition(
4311 latest_session_consumed_total
);
4314 /* Unknown condition type; internal error. */
4318 if (!latest_sample_result
||
4319 (previous_sample_result
== latest_sample_result
)) {
4321 * Only trigger on a condition evaluation transition.
4323 * NOTE: This edge-triggered logic may not be appropriate for
4324 * future condition types.
4329 if (!evaluation
|| !latest_sample_result
) {
4333 switch (condition_type
) {
4334 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4335 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4336 *evaluation
= lttng_evaluation_buffer_usage_create(
4338 latest_sample
->highest_usage
,
4339 channel_info
->capacity
);
4341 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
4342 *evaluation
= lttng_evaluation_session_consumed_size_create(
4343 latest_session_consumed_total
);
4358 int client_notification_overflow(struct notification_client
*client
)
4361 const struct lttng_notification_channel_message msg
= {
4362 .type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED
,
4365 ASSERT_LOCKED(client
->lock
);
4367 DBG("Dropping notification addressed to client (socket fd = %i)",
4369 if (client
->communication
.outbound
.dropped_notification
) {
4371 * The client already has a "notification dropped" message
4372 * in its outgoing queue. Nothing to do since all
4373 * of those messages are coalesced.
4378 client
->communication
.outbound
.dropped_notification
= true;
4379 ret
= lttng_dynamic_buffer_append(
4380 &client
->communication
.outbound
.payload
.buffer
, &msg
,
4383 PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue",
4390 static int client_handle_transmission_status_wrapper(
4391 struct notification_client
*client
,
4392 enum client_transmission_status status
,
4395 return client_handle_transmission_status(client
, status
,
4396 (struct notification_thread_state
*) user_data
);
4400 int send_evaluation_to_clients(const struct lttng_trigger
*trigger
,
4401 const struct lttng_evaluation
*evaluation
,
4402 struct notification_client_list
* client_list
,
4403 struct notification_thread_state
*state
,
4404 uid_t object_uid
, gid_t object_gid
)
4406 const struct lttng_credentials creds
= {
4407 .uid
= LTTNG_OPTIONAL_INIT_VALUE(object_uid
),
4408 .gid
= LTTNG_OPTIONAL_INIT_VALUE(object_gid
),
4411 return notification_client_list_send_evaluation(client_list
,
4412 trigger
, evaluation
,
4414 client_handle_transmission_status_wrapper
, state
);
4418 * Permission checks relative to notification channel clients are performed
4419 * here. Notice how object, client, and trigger credentials are involved in
4422 * The `object` credentials are the credentials associated with the "subject"
4423 * of a condition. For instance, a `rotation completed` condition applies
4424 * to a session. When that condition is met, it will produce an evaluation
4425 * against a session. Hence, in this case, the `object` credentials are the
4426 * credentials of the "subject" session.
4428 * The `trigger` credentials are the credentials of the user that registered the
4431 * The `client` credentials are the credentials of the user that created a given
4432 * notification channel.
4434 * In terms of visibility, it is expected that non-privilieged users can only
4435 * register triggers against "their" objects (their own sessions and
4436 * applications they are allowed to interact with). They can then open a
4437 * notification channel and subscribe to notifications associated with those
4440 * As for privilieged users, they can register triggers against the objects of
4441 * other users. They can then subscribe to the notifications associated to their
4442 * triggers. Privilieged users _can't_ subscribe to the notifications of
4443 * triggers owned by other users; they must create their own triggers.
4445 * This is more a concern of usability than security. It would be difficult for
4446 * a root user reliably subscribe to a specific set of conditions without
4447 * interference from external users (those could, for instance, unregister
4451 int notification_client_list_send_evaluation(
4452 struct notification_client_list
*client_list
,
4453 const struct lttng_trigger
*trigger
,
4454 const struct lttng_evaluation
*evaluation
,
4455 const struct lttng_credentials
*source_object_creds
,
4456 report_client_transmission_result_cb client_report
,
4460 struct lttng_payload msg_payload
;
4461 struct notification_client_list_element
*client_list_element
, *tmp
;
4462 const struct lttng_notification notification
= {
4463 .trigger
= (struct lttng_trigger
*) trigger
,
4464 .evaluation
= (struct lttng_evaluation
*) evaluation
,
4466 struct lttng_notification_channel_message msg_header
= {
4467 .type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION
,
4469 const struct lttng_credentials
*trigger_creds
=
4470 lttng_trigger_get_credentials(trigger
);
4472 lttng_payload_init(&msg_payload
);
4474 ret
= lttng_dynamic_buffer_append(&msg_payload
.buffer
, &msg_header
,
4475 sizeof(msg_header
));
4480 ret
= lttng_notification_serialize(¬ification
, &msg_payload
);
4482 ERR("Failed to serialize notification");
4487 /* Update payload size. */
4488 ((struct lttng_notification_channel_message
*) msg_payload
.buffer
.data
)
4489 ->size
= (uint32_t)(
4490 msg_payload
.buffer
.size
- sizeof(msg_header
));
4492 /* Update the payload number of fds. */
4494 const struct lttng_payload_view pv
= lttng_payload_view_from_payload(
4495 &msg_payload
, 0, -1);
4497 ((struct lttng_notification_channel_message
*)
4498 msg_payload
.buffer
.data
)->fds
= (uint32_t)
4499 lttng_payload_view_get_fd_handle_count(&pv
);
4502 pthread_mutex_lock(&client_list
->lock
);
4503 cds_list_for_each_entry_safe(client_list_element
, tmp
,
4504 &client_list
->clients_list
, node
) {
4505 enum client_transmission_status transmission_status
;
4506 struct notification_client
*client
=
4507 client_list_element
->client
;
4510 pthread_mutex_lock(&client
->lock
);
4511 if (!client
->communication
.active
) {
4513 * Skip inactive client (protocol error or
4516 DBG("Skipping client at it is marked as inactive");
4520 if (lttng_trigger_is_hidden(trigger
) && !client
->is_sessiond
) {
4522 * Notifications resulting from an hidden trigger are
4523 * only sent to the session daemon.
4525 DBG("Skipping client as the trigger is hidden and the client is not the session daemon");
4529 if (source_object_creds
) {
4530 if (client
->uid
!= lttng_credentials_get_uid(source_object_creds
) &&
4531 client
->gid
!= lttng_credentials_get_gid(source_object_creds
) &&
4534 * Client is not allowed to monitor this
4537 DBG("Skipping client at it does not have the object permission to receive notification for this trigger");
4542 if (client
->uid
!= lttng_credentials_get_uid(trigger_creds
)) {
4543 DBG("Skipping client at it does not have the permission to receive notification for this trigger");
4547 DBG("Sending notification to client (fd = %i, %zu bytes)",
4548 client
->socket
, msg_payload
.buffer
.size
);
4550 if (client_has_outbound_data_left(client
)) {
4552 * Outgoing data is already buffered for this client;
4553 * drop the notification and enqueue a "dropped
4554 * notification" message if this is the first dropped
4555 * notification since the socket spilled-over to the
4558 ret
= client_notification_overflow(client
);
4565 ret
= lttng_payload_copy(&msg_payload
, &client
->communication
.outbound
.payload
);
4571 transmission_status
= client_flush_outgoing_queue(client
);
4572 pthread_mutex_unlock(&client
->lock
);
4573 ret
= client_report(client
, transmission_status
, user_data
);
4576 goto end_unlock_list
;
4582 pthread_mutex_unlock(&client
->lock
);
4585 goto end_unlock_list
;
4591 pthread_mutex_unlock(&client_list
->lock
);
4593 lttng_payload_reset(&msg_payload
);
4598 struct lttng_event_notifier_notification
*recv_one_event_notifier_notification(
4599 int notification_pipe_read_fd
, enum lttng_domain_type domain
)
4603 struct lttng_event_notifier_notification
*notification
= NULL
;
4604 char *capture_buffer
= NULL
;
4605 size_t capture_buffer_size
;
4606 void *reception_buffer
;
4607 size_t reception_size
;
4609 struct lttng_ust_abi_event_notifier_notification ust_notification
;
4610 struct lttng_kernel_abi_event_notifier_notification kernel_notification
;
4612 /* Init lttng_event_notifier_notification */
4614 case LTTNG_DOMAIN_UST
:
4615 reception_buffer
= (void *) &ust_notification
;
4616 reception_size
= sizeof(ust_notification
);
4618 case LTTNG_DOMAIN_KERNEL
:
4619 reception_buffer
= (void *) &kernel_notification
;
4620 reception_size
= sizeof(kernel_notification
);
4627 * The monitoring pipe only holds messages smaller than PIPE_BUF,
4628 * ensuring that read/write of tracer notifications are atomic.
4630 ret
= lttng_read(notification_pipe_read_fd
, reception_buffer
,
4632 if (ret
!= reception_size
) {
4633 PERROR("Failed to read from event source notification pipe: fd = %d, size to read = %zu, ret = %d",
4634 notification_pipe_read_fd
, reception_size
, ret
);
4640 case LTTNG_DOMAIN_UST
:
4641 token
= ust_notification
.token
;
4642 capture_buffer_size
= ust_notification
.capture_buf_size
;
4644 case LTTNG_DOMAIN_KERNEL
:
4645 token
= kernel_notification
.token
;
4646 capture_buffer_size
= kernel_notification
.capture_buf_size
;
4652 if (capture_buffer_size
== 0) {
4653 capture_buffer
= NULL
;
4657 if (capture_buffer_size
> MAX_CAPTURE_SIZE
) {
4658 ERR("Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes",
4659 capture_buffer_size
, MAX_CAPTURE_SIZE
);
4663 capture_buffer
= zmalloc(capture_buffer_size
);
4664 if (!capture_buffer
) {
4665 ERR("Failed to allocate capture buffer");
4669 /* Fetch additional payload (capture). */
4670 ret
= lttng_read(notification_pipe_read_fd
, capture_buffer
, capture_buffer_size
);
4671 if (ret
!= capture_buffer_size
) {
4672 ERR("Failed to read from event source pipe (fd = %i)",
4673 notification_pipe_read_fd
);
4678 notification
= lttng_event_notifier_notification_create(token
, domain
,
4679 capture_buffer
, capture_buffer_size
);
4680 if (notification
== NULL
) {
4685 * Ownership transfered to the lttng_event_notifier_notification object.
4687 capture_buffer
= NULL
;
4690 free(capture_buffer
);
4691 return notification
;
4695 int dispatch_one_event_notifier_notification(struct notification_thread_state
*state
,
4696 struct lttng_event_notifier_notification
*notification
)
4698 struct cds_lfht_node
*node
;
4699 struct cds_lfht_iter iter
;
4700 struct notification_trigger_tokens_ht_element
*element
;
4701 struct lttng_evaluation
*evaluation
= NULL
;
4702 enum action_executor_status executor_status
;
4703 struct notification_client_list
*client_list
= NULL
;
4705 unsigned int capture_count
= 0;
4707 /* Find triggers associated with this token. */
4709 cds_lfht_lookup(state
->trigger_tokens_ht
,
4710 hash_key_u64(¬ification
->tracer_token
, lttng_ht_seed
),
4711 match_trigger_token
, ¬ification
->tracer_token
, &iter
);
4712 node
= cds_lfht_iter_get_node(&iter
);
4713 if (caa_unlikely(!node
)) {
4715 * This is not an error, slow consumption of the tracer
4716 * notifications can lead to situations where a trigger is
4717 * removed but we still get tracer notifications matching a
4718 * trigger that no longer exists.
4724 element
= caa_container_of(node
,
4725 struct notification_trigger_tokens_ht_element
,
4728 if (lttng_condition_event_rule_matches_get_capture_descriptor_count(
4729 lttng_trigger_get_const_condition(element
->trigger
),
4730 &capture_count
) != LTTNG_CONDITION_STATUS_OK
) {
4731 ERR("Failed to get capture count");
4736 if (!notification
->capture_buffer
&& capture_count
!= 0) {
4737 ERR("Expected capture but capture buffer is null");
4742 evaluation
= lttng_evaluation_event_rule_matches_create(
4743 container_of(lttng_trigger_get_const_condition(
4745 struct lttng_condition_event_rule_matches
,
4747 notification
->capture_buffer
,
4748 notification
->capture_buf_size
, false);
4750 if (evaluation
== NULL
) {
4751 ERR("Failed to create event rule matches evaluation while creating and enqueuing action executor job");
4756 client_list
= get_client_list_from_condition(state
,
4757 lttng_trigger_get_const_condition(element
->trigger
));
4758 executor_status
= action_executor_enqueue_trigger(state
->executor
,
4759 element
->trigger
, evaluation
, NULL
, client_list
);
4760 switch (executor_status
) {
4761 case ACTION_EXECUTOR_STATUS_OK
:
4764 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
4766 struct notification_client_list_element
*client_list_element
,
4770 * Not a fatal error; this is expected and simply means the
4771 * executor has too much work queued already.
4775 /* No clients subscribed to notifications for this trigger. */
4780 /* Warn clients that a notification (or more) was dropped. */
4781 pthread_mutex_lock(&client_list
->lock
);
4782 cds_list_for_each_entry_safe(client_list_element
, tmp
,
4783 &client_list
->clients_list
, node
) {
4784 enum client_transmission_status transmission_status
;
4785 struct notification_client
*client
=
4786 client_list_element
->client
;
4788 pthread_mutex_lock(&client
->lock
);
4789 ret
= client_notification_overflow(client
);
4795 transmission_status
=
4796 client_flush_outgoing_queue(client
);
4797 ret
= client_handle_transmission_status(
4798 client
, transmission_status
, state
);
4804 pthread_mutex_unlock(&client
->lock
);
4810 pthread_mutex_unlock(&client_list
->lock
);
4813 case ACTION_EXECUTOR_STATUS_INVALID
:
4814 case ACTION_EXECUTOR_STATUS_ERROR
:
4815 /* Fatal error, shut down everything. */
4816 ERR("Fatal error encoutered while enqueuing action to the action executor");
4820 /* Unhandled error. */
4825 notification_client_list_put(client_list
);
4832 int handle_one_event_notifier_notification(
4833 struct notification_thread_state
*state
,
4834 int pipe
, enum lttng_domain_type domain
)
4837 struct lttng_event_notifier_notification
*notification
= NULL
;
4839 notification
= recv_one_event_notifier_notification(pipe
, domain
);
4840 if (notification
== NULL
) {
4841 /* Reception failed, don't consider it fatal. */
4842 ERR("Error receiving an event notifier notification from tracer: fd = %i, domain = %s",
4843 pipe
, lttng_domain_type_str(domain
));
4847 ret
= dispatch_one_event_notifier_notification(state
, notification
);
4849 ERR("Error dispatching an event notifier notification from tracer: fd = %i, domain = %s",
4850 pipe
, lttng_domain_type_str(domain
));
4855 lttng_event_notifier_notification_destroy(notification
);
4859 int handle_notification_thread_event_notification(struct notification_thread_state
*state
,
4860 int pipe
, enum lttng_domain_type domain
)
4862 return handle_one_event_notifier_notification(state
, pipe
, domain
);
4865 int handle_notification_thread_channel_sample(
4866 struct notification_thread_state
*state
, int pipe
,
4867 enum lttng_domain_type domain
)
4870 struct lttcomm_consumer_channel_monitor_msg sample_msg
;
4871 struct channel_info
*channel_info
;
4872 struct cds_lfht_node
*node
;
4873 struct cds_lfht_iter iter
;
4874 struct lttng_channel_trigger_list
*trigger_list
;
4875 struct lttng_trigger_list_element
*trigger_list_element
;
4876 bool previous_sample_available
= false;
4877 struct channel_state_sample previous_sample
, latest_sample
;
4878 uint64_t previous_session_consumed_total
, latest_session_consumed_total
;
4879 struct lttng_credentials channel_creds
;
4882 * The monitoring pipe only holds messages smaller than PIPE_BUF,
4883 * ensuring that read/write of sampling messages are atomic.
4885 ret
= lttng_read(pipe
, &sample_msg
, sizeof(sample_msg
));
4886 if (ret
!= sizeof(sample_msg
)) {
4887 ERR("Failed to read from monitoring pipe (fd = %i)",
4894 latest_sample
.key
.key
= sample_msg
.key
;
4895 latest_sample
.key
.domain
= domain
;
4896 latest_sample
.highest_usage
= sample_msg
.highest
;
4897 latest_sample
.lowest_usage
= sample_msg
.lowest
;
4898 latest_sample
.channel_total_consumed
= sample_msg
.total_consumed
;
4902 /* Retrieve the channel's informations */
4903 cds_lfht_lookup(state
->channels_ht
,
4904 hash_channel_key(&latest_sample
.key
),
4908 node
= cds_lfht_iter_get_node(&iter
);
4909 if (caa_unlikely(!node
)) {
4911 * Not an error since the consumer can push a sample to the pipe
4912 * and the rest of the session daemon could notify us of the
4913 * channel's destruction before we get a chance to process that
4916 DBG("Received a sample for an unknown channel from consumerd, key = %" PRIu64
" in %s domain",
4917 latest_sample
.key
.key
,
4918 lttng_domain_type_str(domain
));
4921 channel_info
= caa_container_of(node
, struct channel_info
,
4923 DBG("Handling channel sample for channel %s (key = %" PRIu64
") in session %s (highest usage = %" PRIu64
", lowest usage = %" PRIu64
", total consumed = %" PRIu64
")",
4925 latest_sample
.key
.key
,
4926 channel_info
->session_info
->name
,
4927 latest_sample
.highest_usage
,
4928 latest_sample
.lowest_usage
,
4929 latest_sample
.channel_total_consumed
);
4931 previous_session_consumed_total
=
4932 channel_info
->session_info
->consumed_data_size
;
4934 /* Retrieve the channel's last sample, if it exists, and update it. */
4935 cds_lfht_lookup(state
->channel_state_ht
,
4936 hash_channel_key(&latest_sample
.key
),
4937 match_channel_state_sample
,
4940 node
= cds_lfht_iter_get_node(&iter
);
4941 if (caa_likely(node
)) {
4942 struct channel_state_sample
*stored_sample
;
4944 /* Update the sample stored. */
4945 stored_sample
= caa_container_of(node
,
4946 struct channel_state_sample
,
4947 channel_state_ht_node
);
4949 memcpy(&previous_sample
, stored_sample
,
4950 sizeof(previous_sample
));
4951 stored_sample
->highest_usage
= latest_sample
.highest_usage
;
4952 stored_sample
->lowest_usage
= latest_sample
.lowest_usage
;
4953 stored_sample
->channel_total_consumed
= latest_sample
.channel_total_consumed
;
4954 previous_sample_available
= true;
4956 latest_session_consumed_total
=
4957 previous_session_consumed_total
+
4958 (latest_sample
.channel_total_consumed
- previous_sample
.channel_total_consumed
);
4961 * This is the channel's first sample, allocate space for and
4962 * store the new sample.
4964 struct channel_state_sample
*stored_sample
;
4966 stored_sample
= zmalloc(sizeof(*stored_sample
));
4967 if (!stored_sample
) {
4972 memcpy(stored_sample
, &latest_sample
, sizeof(*stored_sample
));
4973 cds_lfht_node_init(&stored_sample
->channel_state_ht_node
);
4974 cds_lfht_add(state
->channel_state_ht
,
4975 hash_channel_key(&stored_sample
->key
),
4976 &stored_sample
->channel_state_ht_node
);
4978 latest_session_consumed_total
=
4979 previous_session_consumed_total
+
4980 latest_sample
.channel_total_consumed
;
4983 channel_info
->session_info
->consumed_data_size
=
4984 latest_session_consumed_total
;
4986 /* Find triggers associated with this channel. */
4987 cds_lfht_lookup(state
->channel_triggers_ht
,
4988 hash_channel_key(&latest_sample
.key
),
4989 match_channel_trigger_list
,
4992 node
= cds_lfht_iter_get_node(&iter
);
4993 if (caa_likely(!node
)) {
4997 channel_creds
= (typeof(channel_creds
)) {
4998 .uid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->uid
),
4999 .gid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->gid
),
5002 trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
5003 channel_triggers_ht_node
);
5004 cds_list_for_each_entry(trigger_list_element
, &trigger_list
->list
,
5006 const struct lttng_condition
*condition
;
5007 struct lttng_trigger
*trigger
;
5008 struct notification_client_list
*client_list
= NULL
;
5009 struct lttng_evaluation
*evaluation
= NULL
;
5010 enum action_executor_status executor_status
;
5013 trigger
= trigger_list_element
->trigger
;
5014 condition
= lttng_trigger_get_const_condition(trigger
);
5018 * Check if any client is subscribed to the result of this
5021 client_list
= get_client_list_from_condition(state
, condition
);
5023 ret
= evaluate_buffer_condition(condition
, &evaluation
, state
,
5024 previous_sample_available
? &previous_sample
: NULL
,
5026 previous_session_consumed_total
,
5027 latest_session_consumed_total
,
5029 if (caa_unlikely(ret
)) {
5033 if (caa_likely(!evaluation
)) {
5038 * Ownership of `evaluation` transferred to the action executor
5039 * no matter the result.
5041 executor_status
= action_executor_enqueue_trigger(
5042 state
->executor
, trigger
, evaluation
,
5043 &channel_creds
, client_list
);
5045 switch (executor_status
) {
5046 case ACTION_EXECUTOR_STATUS_OK
:
5048 case ACTION_EXECUTOR_STATUS_ERROR
:
5049 case ACTION_EXECUTOR_STATUS_INVALID
:
5051 * TODO Add trigger identification (name/id) when
5052 * it is added to the API.
5054 ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
5057 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
5059 * TODO Add trigger identification (name/id) when
5060 * it is added to the API.
5062 * Not a fatal error.
5064 WARN("No space left when enqueuing action associated with buffer-condition trigger");
5072 notification_client_list_put(client_list
);
5073 if (caa_unlikely(ret
)) {