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.hpp"
12 #include <urcu/rculfhash.h>
14 #include <common/defaults.hpp>
15 #include <common/error.hpp>
16 #include <common/futex.hpp>
17 #include <common/unix.hpp>
18 #include <common/dynamic-buffer.hpp>
19 #include <common/hashtable/utils.hpp>
20 #include <common/sessiond-comm/sessiond-comm.hpp>
21 #include <common/macros.hpp>
22 #include <lttng/condition/condition.h>
23 #include <lttng/action/action-internal.hpp>
24 #include <lttng/action/list-internal.hpp>
25 #include <lttng/domain-internal.hpp>
26 #include <lttng/notification/notification-internal.hpp>
27 #include <lttng/condition/condition-internal.hpp>
28 #include <lttng/condition/buffer-usage-internal.hpp>
29 #include <lttng/condition/session-consumed-size-internal.hpp>
30 #include <lttng/condition/session-rotation-internal.hpp>
31 #include <lttng/condition/event-rule-matches-internal.hpp>
32 #include <lttng/domain-internal.hpp>
33 #include <lttng/notification/channel-internal.hpp>
34 #include <lttng/trigger/trigger-internal.hpp>
35 #include <lttng/event-rule/event-rule-internal.hpp>
36 #include <lttng/location-internal.hpp>
43 #include "condition-internal.hpp"
44 #include "event-notifier-error-accounting.hpp"
45 #include "notification-thread.hpp"
46 #include "notification-thread-events.hpp"
47 #include "notification-thread-commands.hpp"
48 #include "lttng-sessiond.hpp"
51 #define CLIENT_POLL_EVENTS_IN (LPOLLIN | 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_channel_trigger_list
{
65 struct channel_key channel_key
;
66 /* List of struct lttng_trigger_list_element. */
67 struct cds_list_head list
;
68 /* Node in the channel_triggers_ht */
69 struct cds_lfht_node channel_triggers_ht_node
;
70 /* call_rcu delayed reclaim. */
71 struct rcu_head rcu_node
;
75 * List of triggers applying to a given session.
78 * - lttng_session_trigger_list_create()
79 * - lttng_session_trigger_list_build()
80 * - lttng_session_trigger_list_destroy()
81 * - lttng_session_trigger_list_add()
83 struct lttng_session_trigger_list
{
85 /* List of struct lttng_trigger_list_element. */
86 struct cds_list_head list
;
87 /* Node in the session_triggers_ht */
88 struct cds_lfht_node session_triggers_ht_node
;
90 * Weak reference to the notification system's session triggers
93 * The session trigger list structure structure is owned by
94 * the session's session_info.
96 * The session_info is kept alive the the channel_infos holding a
97 * reference to it (reference counting). When those channels are
98 * destroyed (at runtime or on teardown), the reference they hold
99 * to the session_info are released. On destruction of session_info,
100 * session_info_destroy() will remove the list of triggers applying
101 * to this session from the notification system's state.
103 * This implies that the session_triggers_ht must be destroyed
104 * after the channels.
106 struct cds_lfht
*session_triggers_ht
;
107 /* Used for delayed RCU reclaim. */
108 struct rcu_head rcu_node
;
112 struct lttng_trigger_list_element
{
113 /* No ownership of the trigger object is assumed. */
114 struct lttng_trigger
*trigger
;
115 struct cds_list_head node
;
118 struct lttng_trigger_ht_element
{
119 struct lttng_trigger
*trigger
;
120 struct cds_lfht_node node
;
121 struct cds_lfht_node node_by_name_uid
;
122 struct cds_list_head client_list_trigger_node
;
123 /* call_rcu delayed reclaim. */
124 struct rcu_head rcu_node
;
127 struct lttng_condition_list_element
{
128 struct lttng_condition
*condition
;
129 struct cds_list_head node
;
132 struct channel_state_sample
{
133 struct channel_key key
;
134 struct cds_lfht_node channel_state_ht_node
;
135 uint64_t highest_usage
;
136 uint64_t lowest_usage
;
137 /* call_rcu delayed reclaim. */
138 struct rcu_head rcu_node
;
142 static unsigned long hash_channel_key(struct channel_key
*key
);
143 static int evaluate_buffer_condition(const struct lttng_condition
*condition
,
144 struct lttng_evaluation
**evaluation
,
145 const struct notification_thread_state
*state
,
146 const struct channel_state_sample
*previous_sample
,
147 const struct channel_state_sample
*latest_sample
,
148 struct channel_info
*channel_info
);
150 int send_evaluation_to_clients(const struct lttng_trigger
*trigger
,
151 const struct lttng_evaluation
*evaluation
,
152 struct notification_client_list
*client_list
,
153 struct notification_thread_state
*state
,
154 uid_t channel_uid
, gid_t channel_gid
);
157 /* session_info API */
159 void session_info_destroy(void *_data
);
161 void session_info_get(struct session_info
*session_info
);
163 void session_info_put(struct session_info
*session_info
);
165 struct session_info
*session_info_create(uint64_t id
,
169 struct lttng_session_trigger_list
*trigger_list
,
170 struct cds_lfht
*sessions_ht
);
171 static void session_info_add_channel(
172 struct session_info
*session_info
, struct channel_info
*channel_info
);
174 void session_info_remove_channel(struct session_info
*session_info
,
175 struct channel_info
*channel_info
);
177 /* lttng_session_trigger_list API */
179 struct lttng_session_trigger_list
*lttng_session_trigger_list_create(
180 const char *session_name
,
181 struct cds_lfht
*session_triggers_ht
);
183 struct lttng_session_trigger_list
*lttng_session_trigger_list_build(
184 const struct notification_thread_state
*state
,
185 const char *session_name
);
187 void lttng_session_trigger_list_destroy(
188 struct lttng_session_trigger_list
*list
);
190 int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
191 struct lttng_trigger
*trigger
);
194 int client_handle_transmission_status(
195 struct notification_client
*client
,
196 enum client_transmission_status transmission_status
,
197 struct notification_thread_state
*state
);
200 int handle_one_event_notifier_notification(
201 struct notification_thread_state
*state
,
202 int pipe
, enum lttng_domain_type domain
);
205 void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
);
208 int match_client_socket(struct cds_lfht_node
*node
, const void *key
)
210 /* This double-cast is intended to supress pointer-to-cast warning. */
211 const int socket
= (int) (intptr_t) key
;
212 const struct notification_client
*client
= caa_container_of(node
,
213 struct notification_client
, client_socket_ht_node
);
215 return client
->socket
== socket
;
219 int match_client_id(struct cds_lfht_node
*node
, const void *key
)
221 /* This double-cast is intended to supress pointer-to-cast warning. */
222 const notification_client_id id
= *((notification_client_id
*) key
);
223 const struct notification_client
*client
= lttng::utils::container_of(
224 node
, ¬ification_client::client_id_ht_node
);
226 return client
->id
== id
;
230 int match_channel_trigger_list(struct cds_lfht_node
*node
, const void *key
)
232 struct channel_key
*channel_key
= (struct channel_key
*) key
;
233 struct lttng_channel_trigger_list
*trigger_list
;
235 trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
236 channel_triggers_ht_node
);
238 return !!((channel_key
->key
== trigger_list
->channel_key
.key
) &&
239 (channel_key
->domain
== trigger_list
->channel_key
.domain
));
243 int match_session_trigger_list(struct cds_lfht_node
*node
, const void *key
)
245 const char *session_name
= (const char *) key
;
246 struct lttng_session_trigger_list
*trigger_list
;
248 trigger_list
= caa_container_of(node
, struct lttng_session_trigger_list
,
249 session_triggers_ht_node
);
251 return !!(strcmp(trigger_list
->session_name
, session_name
) == 0);
255 int match_channel_state_sample(struct cds_lfht_node
*node
, const void *key
)
257 struct channel_key
*channel_key
= (struct channel_key
*) key
;
258 struct channel_state_sample
*sample
;
260 sample
= caa_container_of(node
, struct channel_state_sample
,
261 channel_state_ht_node
);
263 return !!((channel_key
->key
== sample
->key
.key
) &&
264 (channel_key
->domain
== sample
->key
.domain
));
268 int match_channel_info(struct cds_lfht_node
*node
, const void *key
)
270 struct channel_key
*channel_key
= (struct channel_key
*) key
;
271 struct channel_info
*channel_info
;
273 channel_info
= caa_container_of(node
, struct channel_info
,
276 return !!((channel_key
->key
== channel_info
->key
.key
) &&
277 (channel_key
->domain
== channel_info
->key
.domain
));
281 int match_trigger(struct cds_lfht_node
*node
, const void *key
)
283 struct lttng_trigger
*trigger_key
= (struct lttng_trigger
*) key
;
284 struct lttng_trigger_ht_element
*trigger_ht_element
;
286 trigger_ht_element
= caa_container_of(node
, struct lttng_trigger_ht_element
,
289 return !!lttng_trigger_is_equal(trigger_key
, trigger_ht_element
->trigger
);
293 int match_trigger_token(struct cds_lfht_node
*node
, const void *key
)
295 const uint64_t *_key
= (uint64_t *) key
;
296 struct notification_trigger_tokens_ht_element
*element
;
298 element
= caa_container_of(node
,
299 struct notification_trigger_tokens_ht_element
, node
);
300 return *_key
== element
->token
;
304 int match_client_list_condition(struct cds_lfht_node
*node
, const void *key
)
306 struct lttng_condition
*condition_key
= (struct lttng_condition
*) key
;
307 struct notification_client_list
*client_list
;
308 const struct lttng_condition
*condition
;
310 LTTNG_ASSERT(condition_key
);
312 client_list
= caa_container_of(node
, struct notification_client_list
,
313 notification_trigger_clients_ht_node
);
314 condition
= client_list
->condition
;
316 return !!lttng_condition_is_equal(condition_key
, condition
);
320 int match_session_info(struct cds_lfht_node
*node
, const void *key
)
322 const auto session_id
= *((uint64_t *) key
);
323 const auto *session_info
= lttng::utils::container_of(
324 node
, &session_info::sessions_ht_node
);
326 return session_id
== session_info
->id
;
330 unsigned long hash_session_info_id(uint64_t id
)
332 return hash_key_u64(&id
, lttng_ht_seed
);
336 unsigned long hash_session_info(const struct session_info
*session_info
)
338 return hash_session_info_id(session_info
->id
);
342 struct session_info
*get_session_info_by_id(
343 const struct notification_thread_state
*state
, uint64_t id
)
345 struct cds_lfht_iter iter
;
346 struct cds_lfht_node
*node
;
347 lttng::urcu::read_lock_guard read_lock_guard
;
349 cds_lfht_lookup(state
->sessions_ht
,
350 hash_session_info_id(id
),
354 node
= cds_lfht_iter_get_node(&iter
);
357 auto session_info
= lttng::utils::container_of(node
, &session_info::sessions_ht_node
);
359 session_info_get(session_info
);
367 struct session_info
*get_session_info_by_name(
368 const struct notification_thread_state
*state
, const char *name
)
371 const auto found
= sample_session_id_by_name(name
, &session_id
);
373 return found
? get_session_info_by_id(state
, session_id
) : NULL
;
377 const char *notification_command_type_str(
378 enum notification_thread_command_type type
)
381 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
382 return "REGISTER_TRIGGER";
383 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
384 return "UNREGISTER_TRIGGER";
385 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
386 return "ADD_CHANNEL";
387 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
388 return "REMOVE_CHANNEL";
389 case NOTIFICATION_COMMAND_TYPE_ADD_SESSION
:
390 return "ADD_SESSION";
391 case NOTIFICATION_COMMAND_TYPE_REMOVE_SESSION
:
392 return "REMOVE_SESSION";
393 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
394 return "SESSION_ROTATION_ONGOING";
395 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
396 return "SESSION_ROTATION_COMPLETED";
397 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
398 return "ADD_TRACER_EVENT_SOURCE";
399 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
400 return "REMOVE_TRACER_EVENT_SOURCE";
401 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
402 return "LIST_TRIGGERS";
403 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
404 return "GET_TRIGGER";
405 case NOTIFICATION_COMMAND_TYPE_QUIT
:
407 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
408 return "CLIENT_COMMUNICATION_UPDATE";
415 * Match trigger based on name and credentials only.
416 * Name duplication is NOT allowed for the same uid.
419 int match_trigger_by_name_uid(struct cds_lfht_node
*node
,
423 const char *element_trigger_name
;
424 const char *key_name
;
425 enum lttng_trigger_status status
;
426 const struct lttng_credentials
*key_creds
;
427 const struct lttng_credentials
*node_creds
;
428 const struct lttng_trigger
*trigger_key
=
429 (const struct lttng_trigger
*) key
;
430 const struct lttng_trigger_ht_element
*trigger_ht_element
=
431 caa_container_of(node
,
432 struct lttng_trigger_ht_element
,
435 status
= lttng_trigger_get_name(trigger_ht_element
->trigger
,
436 &element_trigger_name
);
437 element_trigger_name
= status
== LTTNG_TRIGGER_STATUS_OK
?
438 element_trigger_name
: NULL
;
440 status
= lttng_trigger_get_name(trigger_key
, &key_name
);
441 key_name
= status
== LTTNG_TRIGGER_STATUS_OK
? key_name
: NULL
;
445 * Consider null names as not equal. This is to maintain backwards
446 * compatibility with pre-2.13 anonymous triggers. Multiples anonymous
447 * triggers are allowed for a given user.
449 if (!element_trigger_name
|| !key_name
) {
453 if (strcmp(element_trigger_name
, key_name
) != 0) {
457 /* Compare the owners' UIDs. */
458 key_creds
= lttng_trigger_get_credentials(trigger_key
);
459 node_creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
461 match
= lttng_credentials_is_equal_uid(key_creds
, node_creds
);
468 * Hash trigger based on name and credentials only.
471 unsigned long hash_trigger_by_name_uid(const struct lttng_trigger
*trigger
)
473 unsigned long hash
= 0;
474 const struct lttng_credentials
*trigger_creds
;
475 const char *trigger_name
;
476 enum lttng_trigger_status status
;
478 status
= lttng_trigger_get_name(trigger
, &trigger_name
);
479 if (status
== LTTNG_TRIGGER_STATUS_OK
) {
480 hash
= hash_key_str(trigger_name
, lttng_ht_seed
);
483 trigger_creds
= lttng_trigger_get_credentials(trigger
);
484 hash
^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds
->uid
),
491 unsigned long hash_channel_key(struct channel_key
*key
)
493 unsigned long key_hash
= hash_key_u64(&key
->key
, lttng_ht_seed
);
494 unsigned long domain_hash
= hash_key_ulong(
495 (void *) (unsigned long) key
->domain
, lttng_ht_seed
);
497 return key_hash
^ domain_hash
;
501 unsigned long hash_client_socket(int socket
)
503 return hash_key_ulong((void *) (unsigned long) socket
, lttng_ht_seed
);
507 unsigned long hash_client_id(notification_client_id id
)
509 return hash_key_u64(&id
, lttng_ht_seed
);
513 * Get the type of object to which a given condition applies. Bindings let
514 * the notification system evaluate a trigger's condition when a given
515 * object's state is updated.
517 * For instance, a condition bound to a channel will be evaluated everytime
518 * the channel's state is changed by a channel monitoring sample.
521 enum lttng_object_type
get_condition_binding_object(
522 const struct lttng_condition
*condition
)
524 switch (lttng_condition_get_type(condition
)) {
525 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
526 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
527 return LTTNG_OBJECT_TYPE_CHANNEL
;
528 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
529 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
530 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
531 return LTTNG_OBJECT_TYPE_SESSION
;
532 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
533 return LTTNG_OBJECT_TYPE_NONE
;
535 return LTTNG_OBJECT_TYPE_UNKNOWN
;
540 void free_channel_info_rcu(struct rcu_head
*node
)
542 free(lttng::utils::container_of(node
, &channel_info::rcu_node
));
546 void channel_info_destroy(struct channel_info
*channel_info
)
552 if (channel_info
->session_info
) {
553 session_info_remove_channel(channel_info
->session_info
,
555 session_info_put(channel_info
->session_info
);
557 if (channel_info
->name
) {
558 free(channel_info
->name
);
560 call_rcu(&channel_info
->rcu_node
, free_channel_info_rcu
);
564 void free_session_info_rcu(struct rcu_head
*node
)
566 free(lttng::utils::container_of(node
, &session_info::rcu_node
));
569 /* Don't call directly, use the ref-counting mechanism. */
571 void session_info_destroy(void *_data
)
573 struct session_info
*session_info
= (struct session_info
*) _data
;
576 LTTNG_ASSERT(session_info
);
577 if (session_info
->channel_infos_ht
) {
578 ret
= cds_lfht_destroy(session_info
->channel_infos_ht
, NULL
);
580 ERR("Failed to destroy channel information hash table");
583 lttng_session_trigger_list_destroy(session_info
->trigger_list
);
586 cds_lfht_del(session_info
->sessions_ht
,
587 &session_info
->sessions_ht_node
);
589 free(session_info
->name
);
590 lttng_trace_archive_location_put(session_info
->last_state_sample
.rotation
.location
);
591 call_rcu(&session_info
->rcu_node
, free_session_info_rcu
);
595 void session_info_get(struct session_info
*session_info
)
600 lttng_ref_get(&session_info
->ref
);
604 void session_info_put(struct session_info
*session_info
)
609 lttng_ref_put(&session_info
->ref
);
613 struct session_info
*session_info_create(uint64_t id
,
617 struct lttng_session_trigger_list
*trigger_list
,
618 struct cds_lfht
*sessions_ht
)
620 struct session_info
*session_info
;
624 session_info
= zmalloc
<struct session_info
>();
629 lttng_ref_init(&session_info
->ref
, session_info_destroy
);
631 session_info
->channel_infos_ht
= cds_lfht_new(DEFAULT_HT_SIZE
,
632 1, 0, CDS_LFHT_AUTO_RESIZE
| CDS_LFHT_ACCOUNTING
, NULL
);
633 if (!session_info
->channel_infos_ht
) {
637 cds_lfht_node_init(&session_info
->sessions_ht_node
);
638 session_info
->id
= id
;
639 session_info
->name
= strdup(name
);
640 if (!session_info
->name
) {
644 session_info
->uid
= uid
;
645 session_info
->gid
= gid
;
646 session_info
->trigger_list
= trigger_list
;
647 session_info
->sessions_ht
= sessions_ht
;
651 session_info_put(session_info
);
656 void session_info_add_channel(struct session_info
*session_info
,
657 struct channel_info
*channel_info
)
660 cds_lfht_add(session_info
->channel_infos_ht
,
661 hash_channel_key(&channel_info
->key
),
662 &channel_info
->session_info_channels_ht_node
);
667 void session_info_remove_channel(struct session_info
*session_info
,
668 struct channel_info
*channel_info
)
671 cds_lfht_del(session_info
->channel_infos_ht
,
672 &channel_info
->session_info_channels_ht_node
);
677 struct channel_info
*channel_info_create(const char *channel_name
,
678 struct channel_key
*channel_key
, uint64_t channel_capacity
,
679 struct session_info
*session_info
)
681 struct channel_info
*channel_info
= zmalloc
<struct channel_info
>();
687 cds_lfht_node_init(&channel_info
->channels_ht_node
);
688 cds_lfht_node_init(&channel_info
->session_info_channels_ht_node
);
689 memcpy(&channel_info
->key
, channel_key
, sizeof(*channel_key
));
690 channel_info
->capacity
= channel_capacity
;
692 channel_info
->name
= strdup(channel_name
);
693 if (!channel_info
->name
) {
698 * Set the references between session and channel infos:
699 * - channel_info holds a strong reference to session_info
700 * - session_info holds a weak reference to channel_info
702 session_info_get(session_info
);
703 session_info_add_channel(session_info
, channel_info
);
704 channel_info
->session_info
= session_info
;
708 channel_info_destroy(channel_info
);
712 bool notification_client_list_get(struct notification_client_list
*list
)
714 return urcu_ref_get_unless_zero(&list
->ref
);
718 void free_notification_client_list_rcu(struct rcu_head
*node
)
720 free(caa_container_of(node
, struct notification_client_list
,
725 void notification_client_list_release(struct urcu_ref
*list_ref
)
727 struct notification_client_list
*list
=
728 lttng::utils::container_of(list_ref
, ¬ification_client_list::ref
);
729 struct notification_client_list_element
*client_list_element
, *tmp
;
731 lttng_condition_put(list
->condition
);
733 if (list
->notification_trigger_clients_ht
) {
736 cds_lfht_del(list
->notification_trigger_clients_ht
,
737 &list
->notification_trigger_clients_ht_node
);
739 list
->notification_trigger_clients_ht
= NULL
;
741 cds_list_for_each_entry_safe(client_list_element
, tmp
,
742 &list
->clients_list
, node
) {
743 free(client_list_element
);
746 LTTNG_ASSERT(cds_list_empty(&list
->triggers_list
));
748 pthread_mutex_destroy(&list
->lock
);
749 call_rcu(&list
->rcu_node
, free_notification_client_list_rcu
);
753 bool condition_applies_to_client(const struct lttng_condition
*condition
,
754 struct notification_client
*client
)
756 bool applies
= false;
757 struct lttng_condition_list_element
*condition_list_element
;
759 cds_list_for_each_entry(condition_list_element
, &client
->condition_list
,
761 applies
= lttng_condition_is_equal(
762 condition_list_element
->condition
,
773 struct notification_client_list
*notification_client_list_create(
774 struct notification_thread_state
*state
,
775 const struct lttng_condition
*condition
)
777 struct notification_client
*client
;
778 struct cds_lfht_iter iter
;
779 struct notification_client_list
*client_list
;
781 client_list
= zmalloc
<notification_client_list
>();
783 PERROR("Failed to allocate notification client list");
787 pthread_mutex_init(&client_list
->lock
, NULL
);
789 * The trigger that owns the condition has the first reference to this
792 urcu_ref_init(&client_list
->ref
);
793 cds_lfht_node_init(&client_list
->notification_trigger_clients_ht_node
);
794 CDS_INIT_LIST_HEAD(&client_list
->clients_list
);
795 CDS_INIT_LIST_HEAD(&client_list
->triggers_list
);
798 * Create a copy of the condition so that it's independent of any
799 * trigger. The client list may outlive the trigger object (which owns
800 * the condition) that is used to create it.
802 client_list
->condition
= lttng_condition_copy(condition
);
804 /* Build a list of clients to which this new condition applies. */
805 cds_lfht_for_each_entry (state
->client_socket_ht
, &iter
, client
,
806 client_socket_ht_node
) {
807 struct notification_client_list_element
*client_list_element
;
809 if (!condition_applies_to_client(condition
, client
)) {
813 client_list_element
= zmalloc
<notification_client_list_element
>();
814 if (!client_list_element
) {
815 goto error_put_client_list
;
818 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
819 client_list_element
->client
= client
;
820 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
823 client_list
->notification_trigger_clients_ht
=
824 state
->notification_trigger_clients_ht
;
828 * Add the client list to the global list of client list.
830 cds_lfht_add_unique(state
->notification_trigger_clients_ht
,
831 lttng_condition_hash(client_list
->condition
),
832 match_client_list_condition
,
833 client_list
->condition
,
834 &client_list
->notification_trigger_clients_ht_node
);
838 error_put_client_list
:
839 notification_client_list_put(client_list
);
846 void notification_client_list_put(struct notification_client_list
*list
)
851 return urcu_ref_put(&list
->ref
, notification_client_list_release
);
854 /* Provides a reference to the returned list. */
856 struct notification_client_list
*get_client_list_from_condition(
857 struct notification_thread_state
*state
,
858 const struct lttng_condition
*condition
)
860 struct cds_lfht_node
*node
;
861 struct cds_lfht_iter iter
;
862 struct notification_client_list
*list
= NULL
;
865 cds_lfht_lookup(state
->notification_trigger_clients_ht
,
866 lttng_condition_hash(condition
),
867 match_client_list_condition
,
870 node
= cds_lfht_iter_get_node(&iter
);
872 list
= lttng::utils::container_of(node
,
873 ¬ification_client_list::notification_trigger_clients_ht_node
);
874 list
= notification_client_list_get(list
) ? list
: NULL
;
882 int evaluate_channel_condition_for_client(
883 const struct lttng_condition
*condition
,
884 struct notification_thread_state
*state
,
885 struct lttng_evaluation
**evaluation
,
886 uid_t
*session_uid
, gid_t
*session_gid
)
889 struct cds_lfht_iter iter
;
890 struct cds_lfht_node
*node
;
891 struct channel_info
*channel_info
= NULL
;
892 struct channel_key
*channel_key
= NULL
;
893 struct channel_state_sample
*last_sample
= NULL
;
894 struct lttng_channel_trigger_list
*channel_trigger_list
= NULL
;
898 /* Find the channel associated with the condition. */
899 cds_lfht_for_each_entry(state
->channel_triggers_ht
, &iter
,
900 channel_trigger_list
, channel_triggers_ht_node
) {
901 struct lttng_trigger_list_element
*element
;
903 cds_list_for_each_entry(element
, &channel_trigger_list
->list
, node
) {
904 const struct lttng_condition
*current_condition
=
905 lttng_trigger_get_const_condition(
908 LTTNG_ASSERT(current_condition
);
909 if (!lttng_condition_is_equal(condition
,
910 current_condition
)) {
914 /* Found the trigger, save the channel key. */
915 channel_key
= &channel_trigger_list
->channel_key
;
919 /* The channel key was found stop iteration. */
925 /* No channel found; normal exit. */
926 DBG("No known channel associated with newly subscribed-to condition");
931 /* Fetch channel info for the matching channel. */
932 cds_lfht_lookup(state
->channels_ht
,
933 hash_channel_key(channel_key
),
937 node
= cds_lfht_iter_get_node(&iter
);
939 channel_info
= caa_container_of(node
, struct channel_info
,
942 /* Retrieve the channel's last sample, if it exists. */
943 cds_lfht_lookup(state
->channel_state_ht
,
944 hash_channel_key(channel_key
),
945 match_channel_state_sample
,
948 node
= cds_lfht_iter_get_node(&iter
);
950 last_sample
= caa_container_of(node
,
951 struct channel_state_sample
,
952 channel_state_ht_node
);
954 /* Nothing to evaluate, no sample was ever taken. Normal exit */
955 DBG("No channel sample associated with newly subscribed-to condition");
960 ret
= evaluate_buffer_condition(condition
, evaluation
, state
,
964 WARN("Fatal error occurred while evaluating a newly subscribed-to condition");
968 *session_uid
= channel_info
->session_info
->uid
;
969 *session_gid
= channel_info
->session_info
->gid
;
976 const char *get_condition_session_name(const struct lttng_condition
*condition
)
978 const char *session_name
= NULL
;
979 enum lttng_condition_status status
;
981 switch (lttng_condition_get_type(condition
)) {
982 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
983 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
984 status
= lttng_condition_buffer_usage_get_session_name(
985 condition
, &session_name
);
987 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
988 status
= lttng_condition_session_consumed_size_get_session_name(
989 condition
, &session_name
);
991 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
992 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
993 status
= lttng_condition_session_rotation_get_session_name(
994 condition
, &session_name
);
999 if (status
!= LTTNG_CONDITION_STATUS_OK
) {
1000 ERR("Failed to retrieve session rotation condition's session name");
1004 return session_name
;
1008 bool evaluate_session_rotation_ongoing_condition(const struct lttng_condition
*condition
1009 __attribute__((unused
)),
1010 const struct session_state_sample
*sample
)
1012 return sample
->rotation
.ongoing
;
1016 bool evaluate_session_consumed_size_condition(
1017 const struct lttng_condition
*condition
,
1018 const struct session_state_sample
*sample
)
1021 const struct lttng_condition_session_consumed_size
*size_condition
=
1022 lttng::utils::container_of(condition
,
1023 <tng_condition_session_consumed_size::parent
);
1025 threshold
= size_condition
->consumed_threshold_bytes
.value
;
1026 DBG("Session consumed size condition being evaluated: threshold = %" PRIu64
", current size = %" PRIu64
,
1027 threshold
, sample
->consumed_data_size
);
1028 return sample
->consumed_data_size
>= threshold
;
1032 * `new_state` can be NULL to indicate that we are not evaluating a
1033 * state transition. A client subscribed or a trigger was registered and
1034 * we wish to perform an initial evaluation.
1037 int evaluate_session_condition(
1038 const struct lttng_condition
*condition
,
1039 const struct session_info
*session_info
,
1040 const struct session_state_sample
*new_state
,
1041 struct lttng_evaluation
**evaluation
)
1044 bool previous_result
, newest_result
;
1046 switch (lttng_condition_get_type(condition
)) {
1047 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1049 previous_result
= evaluate_session_rotation_ongoing_condition(
1050 condition
, &session_info
->last_state_sample
);
1051 newest_result
= evaluate_session_rotation_ongoing_condition(
1052 condition
, new_state
);
1054 previous_result
= false;
1055 newest_result
= evaluate_session_rotation_ongoing_condition(
1056 condition
, &session_info
->last_state_sample
);
1059 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1061 previous_result
= evaluate_session_consumed_size_condition(
1062 condition
, &session_info
->last_state_sample
);
1063 newest_result
= evaluate_session_consumed_size_condition(
1064 condition
, new_state
);
1066 previous_result
= false;
1067 newest_result
= evaluate_session_consumed_size_condition(
1068 condition
, &session_info
->last_state_sample
);
1071 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1073 * Note that LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED is
1074 * evaluated differently to only consider state transitions without regard for the
1075 * initial state. This is a deliberate choice as it is unlikely that a user would
1076 * expect an action to occur for a rotation that occurred long before the trigger or
1077 * subscription occurred.
1084 previous_result
= !session_info
->last_state_sample
.rotation
.ongoing
;
1085 newest_result
= !new_state
->rotation
.ongoing
;
1092 if (!newest_result
|| (previous_result
== newest_result
)) {
1093 /* Not a state transition, evaluate to false. */
1098 switch (lttng_condition_get_type(condition
)) {
1099 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1101 const auto rotation_id
= new_state
?
1102 new_state
->rotation
.id
:
1103 session_info
->last_state_sample
.rotation
.id
;
1105 *evaluation
= lttng_evaluation_session_rotation_ongoing_create(rotation_id
);
1108 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1110 const auto& sample
= new_state
? *new_state
: session_info
->last_state_sample
;
1111 const auto rotation_id
= sample
.rotation
.id
;
1113 /* Callee acquires a reference to location. */
1114 *evaluation
= lttng_evaluation_session_rotation_completed_create(
1115 rotation_id
, sample
.rotation
.location
);
1118 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1120 const auto latest_session_consumed_total
= new_state
?
1121 new_state
->consumed_data_size
:
1122 session_info
->last_state_sample
.consumed_data_size
;
1124 *evaluation
= lttng_evaluation_session_consumed_size_create(
1125 latest_session_consumed_total
);
1134 ERR("Failed to create session condition evaluation: session name = `%s`",
1135 session_info
->name
);
1146 int evaluate_condition_for_client(const struct lttng_trigger
*trigger
,
1147 const struct lttng_condition
*condition
,
1148 struct notification_client
*client
,
1149 struct notification_thread_state
*state
)
1152 struct lttng_evaluation
*evaluation
= NULL
;
1153 struct notification_client_list client_list
= {
1154 .lock
= PTHREAD_MUTEX_INITIALIZER
,
1157 .triggers_list
= {},
1159 .notification_trigger_clients_ht
= NULL
,
1160 .notification_trigger_clients_ht_node
= {},
1163 struct notification_client_list_element client_list_element
= {};
1164 uid_t object_uid
= 0;
1165 gid_t object_gid
= 0;
1167 LTTNG_ASSERT(trigger
);
1168 LTTNG_ASSERT(condition
);
1169 LTTNG_ASSERT(client
);
1170 LTTNG_ASSERT(state
);
1172 switch (get_condition_binding_object(condition
)) {
1173 case LTTNG_OBJECT_TYPE_SESSION
:
1175 /* Find the session associated with the condition. */
1176 const auto *session_name
= get_condition_session_name(condition
);
1177 auto session_info
= get_session_info_by_name(state
, session_name
);
1178 if (!session_info
) {
1179 /* Not an error, the session doesn't exist yet. */
1180 DBG("Session not found while evaluating session condition for client: session name = `%s`",
1186 object_uid
= session_info
->uid
;
1187 object_gid
= session_info
->gid
;
1189 ret
= evaluate_session_condition(condition
, session_info
, NULL
, &evaluation
);
1190 session_info_put(session_info
);
1193 case LTTNG_OBJECT_TYPE_CHANNEL
:
1194 ret
= evaluate_channel_condition_for_client(condition
, state
,
1195 &evaluation
, &object_uid
, &object_gid
);
1197 case LTTNG_OBJECT_TYPE_NONE
:
1198 DBG("Newly subscribed-to condition not bound to object, nothing to evaluate");
1201 case LTTNG_OBJECT_TYPE_UNKNOWN
:
1211 /* Evaluation yielded nothing. Normal exit. */
1212 DBG("Newly subscribed-to condition evaluated to false, nothing to report to client");
1218 * Create a temporary client list with the client currently
1221 cds_lfht_node_init(&client_list
.notification_trigger_clients_ht_node
);
1222 CDS_INIT_LIST_HEAD(&client_list
.clients_list
);
1224 CDS_INIT_LIST_HEAD(&client_list_element
.node
);
1225 client_list_element
.client
= client
;
1226 cds_list_add(&client_list_element
.node
, &client_list
.clients_list
);
1228 /* Send evaluation result to the newly-subscribed client. */
1229 DBG("Newly subscribed-to condition evaluated to true, notifying client");
1230 ret
= send_evaluation_to_clients(trigger
, evaluation
, &client_list
,
1231 state
, object_uid
, object_gid
);
1238 int notification_thread_client_subscribe(struct notification_client
*client
,
1239 struct lttng_condition
*condition
,
1240 struct notification_thread_state
*state
,
1241 enum lttng_notification_channel_status
*_status
)
1244 struct notification_client_list
*client_list
= NULL
;
1245 struct lttng_condition_list_element
*condition_list_element
= NULL
;
1246 struct notification_client_list_element
*client_list_element
= NULL
;
1247 struct lttng_trigger_ht_element
*trigger_ht_element
;
1248 enum lttng_notification_channel_status status
=
1249 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1252 * Ensure that the client has not already subscribed to this condition
1255 cds_list_for_each_entry(condition_list_element
, &client
->condition_list
, node
) {
1256 if (lttng_condition_is_equal(condition_list_element
->condition
,
1258 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED
;
1263 condition_list_element
= zmalloc
<lttng_condition_list_element
>();
1264 if (!condition_list_element
) {
1268 client_list_element
= zmalloc
<notification_client_list_element
>();
1269 if (!client_list_element
) {
1275 * Add the newly-subscribed condition to the client's subscription list.
1277 CDS_INIT_LIST_HEAD(&condition_list_element
->node
);
1278 condition_list_element
->condition
= condition
;
1280 cds_list_add(&condition_list_element
->node
, &client
->condition_list
);
1282 client_list
= get_client_list_from_condition(
1283 state
, condition_list_element
->condition
);
1286 * No notification-emiting trigger registered with this
1287 * condition. We don't evaluate the condition right away
1288 * since this trigger is not registered yet.
1290 free(client_list_element
);
1295 * The condition to which the client just subscribed is evaluated
1296 * at this point so that conditions that are already TRUE result
1297 * in a notification being sent out.
1299 * Note the iteration on all triggers which share an identical
1300 * `condition` than the one to which the client is registering. This is
1301 * done to ensure that the client receives a distinct notification for
1302 * all triggers that have a `notify` action that have this condition.
1304 pthread_mutex_lock(&client_list
->lock
);
1305 cds_list_for_each_entry(trigger_ht_element
,
1306 &client_list
->triggers_list
, client_list_trigger_node
) {
1307 if (evaluate_condition_for_client(trigger_ht_element
->trigger
, condition_list_element
->condition
,
1309 WARN("Evaluation of a condition on client subscription failed, aborting.");
1311 free(client_list_element
);
1312 pthread_mutex_unlock(&client_list
->lock
);
1316 pthread_mutex_unlock(&client_list
->lock
);
1319 * Add the client to the list of clients interested in a given trigger
1320 * if a "notification" trigger with a corresponding condition was
1323 client_list_element
->client
= client
;
1324 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
1326 pthread_mutex_lock(&client_list
->lock
);
1327 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
1328 pthread_mutex_unlock(&client_list
->lock
);
1334 notification_client_list_put(client_list
);
1336 lttng_condition_destroy(condition
);
1339 free(condition_list_element
);
1340 free(client_list_element
);
1341 lttng_condition_destroy(condition
);
1346 int notification_thread_client_unsubscribe(
1347 struct notification_client
*client
,
1348 struct lttng_condition
*condition
,
1349 struct notification_thread_state
*state
,
1350 enum lttng_notification_channel_status
*_status
)
1352 struct notification_client_list
*client_list
;
1353 struct lttng_condition_list_element
*condition_list_element
,
1355 struct notification_client_list_element
*client_list_element
,
1357 bool condition_found
= false;
1358 enum lttng_notification_channel_status status
=
1359 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1361 /* Remove the condition from the client's condition list. */
1362 cds_list_for_each_entry_safe(condition_list_element
, condition_tmp
,
1363 &client
->condition_list
, node
) {
1364 if (!lttng_condition_is_equal(condition_list_element
->condition
,
1369 cds_list_del(&condition_list_element
->node
);
1371 * The caller may be iterating on the client's conditions to
1372 * tear down a client's connection. In this case, the condition
1373 * will be destroyed at the end.
1375 if (condition
!= condition_list_element
->condition
) {
1376 lttng_condition_destroy(
1377 condition_list_element
->condition
);
1379 free(condition_list_element
);
1380 condition_found
= true;
1384 if (!condition_found
) {
1385 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION
;
1390 * Remove the client from the list of clients interested the trigger
1391 * matching the condition.
1393 client_list
= get_client_list_from_condition(state
, condition
);
1398 pthread_mutex_lock(&client_list
->lock
);
1399 cds_list_for_each_entry_safe(client_list_element
, client_tmp
,
1400 &client_list
->clients_list
, node
) {
1401 if (client_list_element
->client
->id
!= client
->id
) {
1404 cds_list_del(&client_list_element
->node
);
1405 free(client_list_element
);
1408 pthread_mutex_unlock(&client_list
->lock
);
1409 notification_client_list_put(client_list
);
1412 lttng_condition_destroy(condition
);
1420 void free_notification_client_rcu(struct rcu_head
*node
)
1422 free(lttng::utils::container_of(node
, ¬ification_client::rcu_node
));
1426 void notification_client_destroy(struct notification_client
*client
)
1433 * The client object is not reachable by other threads, no need to lock
1436 if (client
->socket
>= 0) {
1437 (void) lttcomm_close_unix_sock(client
->socket
);
1438 client
->socket
= -1;
1440 client
->communication
.active
= false;
1441 lttng_payload_reset(&client
->communication
.inbound
.payload
);
1442 lttng_payload_reset(&client
->communication
.outbound
.payload
);
1443 pthread_mutex_destroy(&client
->lock
);
1444 call_rcu(&client
->rcu_node
, free_notification_client_rcu
);
1448 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1452 struct notification_client
*get_client_from_socket(int socket
,
1453 struct notification_thread_state
*state
)
1455 struct cds_lfht_iter iter
;
1456 struct cds_lfht_node
*node
;
1457 struct notification_client
*client
= NULL
;
1459 ASSERT_RCU_READ_LOCKED();
1461 cds_lfht_lookup(state
->client_socket_ht
,
1462 hash_client_socket(socket
),
1463 match_client_socket
,
1464 (void *) (unsigned long) socket
,
1466 node
= cds_lfht_iter_get_node(&iter
);
1471 client
= caa_container_of(node
, struct notification_client
,
1472 client_socket_ht_node
);
1478 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1482 struct notification_client
*get_client_from_id(notification_client_id id
,
1483 struct notification_thread_state
*state
)
1485 struct cds_lfht_iter iter
;
1486 struct cds_lfht_node
*node
;
1487 struct notification_client
*client
= NULL
;
1489 ASSERT_RCU_READ_LOCKED();
1491 cds_lfht_lookup(state
->client_id_ht
,
1496 node
= cds_lfht_iter_get_node(&iter
);
1501 client
= caa_container_of(node
, struct notification_client
,
1508 bool buffer_usage_condition_applies_to_channel(
1509 const struct lttng_condition
*condition
,
1510 const struct channel_info
*channel_info
)
1512 enum lttng_condition_status status
;
1513 enum lttng_domain_type condition_domain
;
1514 const char *condition_session_name
= NULL
;
1515 const char *condition_channel_name
= NULL
;
1517 status
= lttng_condition_buffer_usage_get_domain_type(condition
,
1519 LTTNG_ASSERT(status
== LTTNG_CONDITION_STATUS_OK
);
1520 if (channel_info
->key
.domain
!= condition_domain
) {
1524 status
= lttng_condition_buffer_usage_get_session_name(
1525 condition
, &condition_session_name
);
1526 LTTNG_ASSERT((status
== LTTNG_CONDITION_STATUS_OK
) && condition_session_name
);
1528 status
= lttng_condition_buffer_usage_get_channel_name(
1529 condition
, &condition_channel_name
);
1530 LTTNG_ASSERT((status
== LTTNG_CONDITION_STATUS_OK
) && condition_channel_name
);
1532 if (strcmp(channel_info
->session_info
->name
, condition_session_name
)) {
1535 if (strcmp(channel_info
->name
, condition_channel_name
)) {
1545 bool trigger_applies_to_channel(const struct lttng_trigger
*trigger
,
1546 const struct channel_info
*channel_info
)
1548 const struct lttng_condition
*condition
;
1549 bool trigger_applies
;
1551 condition
= lttng_trigger_get_const_condition(trigger
);
1556 switch (lttng_condition_get_type(condition
)) {
1557 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
1558 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
1559 trigger_applies
= buffer_usage_condition_applies_to_channel(
1560 condition
, channel_info
);
1566 return trigger_applies
;
1571 /* Must be called with RCU read lock held. */
1573 struct lttng_session_trigger_list
*get_session_trigger_list(
1574 struct notification_thread_state
*state
,
1575 const char *session_name
)
1577 struct lttng_session_trigger_list
*list
= NULL
;
1578 struct cds_lfht_node
*node
;
1579 struct cds_lfht_iter iter
;
1581 ASSERT_RCU_READ_LOCKED();
1583 cds_lfht_lookup(state
->session_triggers_ht
,
1584 hash_key_str(session_name
, lttng_ht_seed
),
1585 match_session_trigger_list
,
1588 node
= cds_lfht_iter_get_node(&iter
);
1591 * Not an error, the list of triggers applying to that session
1592 * will be initialized when the session is created.
1594 DBG("No trigger list found for session \"%s\" as it is not yet known to the notification system",
1599 list
= caa_container_of(node
,
1600 struct lttng_session_trigger_list
,
1601 session_triggers_ht_node
);
1607 * Allocate an empty lttng_session_trigger_list for the session named
1611 struct lttng_session_trigger_list
*lttng_session_trigger_list_create(
1612 const char *session_name
,
1613 struct cds_lfht
*session_triggers_ht
)
1615 struct lttng_session_trigger_list
*list
= NULL
;
1616 char *session_name_copy
= strdup(session_name
);
1618 if (!session_name_copy
) {
1619 PERROR("Failed to allocate session name while building trigger list");
1623 list
= zmalloc
<lttng_session_trigger_list
>();
1625 PERROR("Failed to allocate session trigger list while building trigger list");
1629 list
->session_name
= session_name_copy
;
1630 CDS_INIT_LIST_HEAD(&list
->list
);
1631 cds_lfht_node_init(&list
->session_triggers_ht_node
);
1632 list
->session_triggers_ht
= session_triggers_ht
;
1635 /* Publish the list through the session_triggers_ht. */
1636 cds_lfht_add(session_triggers_ht
,
1637 hash_key_str(session_name
, lttng_ht_seed
),
1638 &list
->session_triggers_ht_node
);
1645 void free_session_trigger_list_rcu(struct rcu_head
*node
)
1647 struct lttng_session_trigger_list
*list
=
1648 caa_container_of(node
, struct lttng_session_trigger_list
, rcu_node
);
1650 free(list
->session_name
);
1655 void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list
*list
)
1657 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1659 /* Empty the list element by element, and then free the list itself. */
1660 cds_list_for_each_entry_safe(trigger_list_element
, tmp
,
1661 &list
->list
, node
) {
1662 cds_list_del(&trigger_list_element
->node
);
1663 free(trigger_list_element
);
1666 /* Unpublish the list from the session_triggers_ht. */
1667 cds_lfht_del(list
->session_triggers_ht
,
1668 &list
->session_triggers_ht_node
);
1670 call_rcu(&list
->rcu_node
, free_session_trigger_list_rcu
);
1674 int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
1675 struct lttng_trigger
*trigger
)
1678 struct lttng_trigger_list_element
*new_element
=
1679 zmalloc
<lttng_trigger_list_element
>();
1685 CDS_INIT_LIST_HEAD(&new_element
->node
);
1686 new_element
->trigger
= trigger
;
1687 cds_list_add(&new_element
->node
, &list
->list
);
1693 bool trigger_applies_to_session(const struct lttng_trigger
*trigger
,
1694 const char *session_name
)
1696 bool applies
= false;
1697 const struct lttng_condition
*condition
;
1699 condition
= lttng_trigger_get_const_condition(trigger
);
1700 switch (lttng_condition_get_type(condition
)) {
1701 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1702 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1703 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1705 const char *condition_session_name
;
1707 condition_session_name
= get_condition_session_name(condition
);
1708 LTTNG_ASSERT(condition_session_name
);
1709 applies
= !strcmp(condition_session_name
, session_name
);
1720 * Allocate and initialize an lttng_session_trigger_list which contains
1721 * all triggers that apply to the session named 'session_name'.
1724 struct lttng_session_trigger_list
*lttng_session_trigger_list_build(
1725 const struct notification_thread_state
*state
,
1726 const char *session_name
)
1728 int trigger_count
= 0;
1729 struct lttng_session_trigger_list
*session_trigger_list
= NULL
;
1730 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
1731 struct cds_lfht_iter iter
;
1733 session_trigger_list
= lttng_session_trigger_list_create(session_name
,
1734 state
->session_triggers_ht
);
1736 /* Add all triggers applying to the session named 'session_name'. */
1737 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
1741 if (!trigger_applies_to_session(trigger_ht_element
->trigger
,
1746 ret
= lttng_session_trigger_list_add(session_trigger_list
,
1747 trigger_ht_element
->trigger
);
1755 DBG("Found %i triggers that apply to newly created session",
1757 return session_trigger_list
;
1759 lttng_session_trigger_list_destroy(session_trigger_list
);
1764 struct session_info
*create_and_publish_session_info(struct notification_thread_state
*state
,
1770 struct session_info
*session
= NULL
;
1771 struct lttng_session_trigger_list
*trigger_list
;
1774 trigger_list
= lttng_session_trigger_list_build(state
, name
);
1775 if (!trigger_list
) {
1779 session
= session_info_create(id
, name
, uid
, gid
, trigger_list
,
1780 state
->sessions_ht
);
1782 ERR("Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
1784 lttng_session_trigger_list_destroy(trigger_list
);
1788 /* Transferred ownership to the new session. */
1789 trigger_list
= NULL
;
1791 if (cds_lfht_add_unique(state
->sessions_ht
, hash_session_info(session
), match_session_info
,
1792 &id
, &session
->sessions_ht_node
) != &session
->sessions_ht_node
) {
1793 ERR("Duplicate session found: name = `%s`, id = %" PRIu64
, name
, id
);
1801 session_info_put(session
);
1806 int handle_notification_thread_command_add_channel(struct notification_thread_state
*state
,
1807 uint64_t session_id
,
1808 const char *channel_name
,
1809 enum lttng_domain_type channel_domain
,
1810 uint64_t channel_key_int
,
1811 uint64_t channel_capacity
,
1812 enum lttng_error_code
*cmd_result
)
1814 struct cds_list_head trigger_list
;
1815 struct channel_info
*new_channel_info
= NULL
;
1816 struct channel_key channel_key
= {
1817 .key
= channel_key_int
,
1818 .domain
= channel_domain
,
1820 struct lttng_channel_trigger_list
*channel_trigger_list
= NULL
;
1821 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
1822 int trigger_count
= 0;
1823 struct cds_lfht_iter iter
;
1824 struct session_info
*session_info
= NULL
;
1826 DBG("Adding channel: channel name = `%s`, session id = %" PRIu64
", channel key = %" PRIu64
", domain = %s",
1827 channel_name
, session_id
, channel_key_int
,
1828 lttng_domain_type_str(channel_domain
));
1830 CDS_INIT_LIST_HEAD(&trigger_list
);
1832 session_info
= get_session_info_by_id(state
, session_id
);
1833 if (!session_info
) {
1834 /* Fatal logic error. */
1835 ERR("Failed to find session while adding channel: session id = %" PRIu64
,
1840 new_channel_info
= channel_info_create(channel_name
, &channel_key
,
1841 channel_capacity
, session_info
);
1842 if (!new_channel_info
) {
1847 /* Build a list of all triggers applying to the new channel. */
1848 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
1850 struct lttng_trigger_list_element
*new_element
;
1852 if (!trigger_applies_to_channel(trigger_ht_element
->trigger
,
1853 new_channel_info
)) {
1857 new_element
= zmalloc
<lttng_trigger_list_element
>();
1862 CDS_INIT_LIST_HEAD(&new_element
->node
);
1863 new_element
->trigger
= trigger_ht_element
->trigger
;
1864 cds_list_add(&new_element
->node
, &trigger_list
);
1869 DBG("Found %i triggers that apply to newly added channel",
1871 channel_trigger_list
= zmalloc
<lttng_channel_trigger_list
>();
1872 if (!channel_trigger_list
) {
1875 channel_trigger_list
->channel_key
= new_channel_info
->key
;
1876 CDS_INIT_LIST_HEAD(&channel_trigger_list
->list
);
1877 cds_lfht_node_init(&channel_trigger_list
->channel_triggers_ht_node
);
1878 cds_list_splice(&trigger_list
, &channel_trigger_list
->list
);
1881 /* Add channel to the channel_ht which owns the channel_infos. */
1882 cds_lfht_add(state
->channels_ht
,
1883 hash_channel_key(&new_channel_info
->key
),
1884 &new_channel_info
->channels_ht_node
);
1886 * Add the list of triggers associated with this channel to the
1887 * channel_triggers_ht.
1889 cds_lfht_add(state
->channel_triggers_ht
,
1890 hash_channel_key(&new_channel_info
->key
),
1891 &channel_trigger_list
->channel_triggers_ht_node
);
1893 session_info_put(session_info
);
1894 *cmd_result
= LTTNG_OK
;
1897 channel_info_destroy(new_channel_info
);
1898 session_info_put(session_info
);
1903 int handle_notification_thread_command_add_session(struct notification_thread_state
*state
,
1904 uint64_t session_id
,
1905 const char *session_name
,
1908 enum lttng_error_code
*cmd_result
)
1912 DBG("Adding session: session name = `%s`, session id = %" PRIu64
", session uid = %d, session gid = %d",
1913 session_name
, session_id
, session_uid
, session_gid
);
1915 auto session
= create_and_publish_session_info(state
, session_id
, session_name
, session_uid
, session_gid
);
1917 PERROR("Failed to add session: session name = `%s`, session id = %" PRIu64
", session uid = %d, session gid = %d",
1918 session_name
, session_id
, session_uid
, session_gid
);
1920 *cmd_result
= LTTNG_ERR_NOMEM
;
1925 * Note that the reference to `session` is not released; this reference is
1926 * the "global" reference that is used to allow look-ups. This reference will
1927 * only be released when the session is removed. See
1928 * handle_notification_thread_command_remove_session.
1931 *cmd_result
= LTTNG_OK
;
1937 int handle_notification_thread_command_remove_session(
1938 struct notification_thread_state
*state
,
1939 uint64_t session_id
,
1940 enum lttng_error_code
*cmd_result
)
1944 DBG("Removing session: session id = %" PRIu64
, session_id
);
1946 auto session
= get_session_info_by_id(state
, session_id
);
1948 ERR("Failed to remove session: session id = %" PRIu64
, session_id
);
1950 *cmd_result
= LTTNG_ERR_NO_SESSION
;
1954 /* Release the reference returned by the look-up, and then release the global reference. */
1955 session_info_put(session
);
1956 session_info_put(session
);
1958 *cmd_result
= LTTNG_OK
;
1964 void free_channel_trigger_list_rcu(struct rcu_head
*node
)
1966 free(caa_container_of(node
, struct lttng_channel_trigger_list
,
1971 void free_channel_state_sample_rcu(struct rcu_head
*node
)
1973 free(caa_container_of(node
, struct channel_state_sample
,
1978 int handle_notification_thread_command_remove_channel(
1979 struct notification_thread_state
*state
,
1980 uint64_t channel_key
, enum lttng_domain_type domain
,
1981 enum lttng_error_code
*cmd_result
)
1983 struct cds_lfht_node
*node
;
1984 struct cds_lfht_iter iter
;
1985 struct lttng_channel_trigger_list
*trigger_list
;
1986 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1987 struct channel_key key
= { .key
= channel_key
, .domain
= domain
};
1988 struct channel_info
*channel_info
;
1990 DBG("Removing channel key = %" PRIu64
" in %s domain",
1991 channel_key
, lttng_domain_type_str(domain
));
1995 cds_lfht_lookup(state
->channel_triggers_ht
,
1996 hash_channel_key(&key
),
1997 match_channel_trigger_list
,
2000 node
= cds_lfht_iter_get_node(&iter
);
2002 * There is a severe internal error if we are being asked to remove a
2003 * channel that doesn't exist.
2006 ERR("Channel being removed is unknown to the notification thread");
2010 /* Free the list of triggers associated with this channel. */
2011 trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
2012 channel_triggers_ht_node
);
2013 cds_list_for_each_entry_safe(trigger_list_element
, tmp
,
2014 &trigger_list
->list
, node
) {
2015 cds_list_del(&trigger_list_element
->node
);
2016 free(trigger_list_element
);
2018 cds_lfht_del(state
->channel_triggers_ht
, node
);
2019 call_rcu(&trigger_list
->rcu_node
, free_channel_trigger_list_rcu
);
2021 /* Free sampled channel state. */
2022 cds_lfht_lookup(state
->channel_state_ht
,
2023 hash_channel_key(&key
),
2024 match_channel_state_sample
,
2027 node
= cds_lfht_iter_get_node(&iter
);
2029 * This is expected to be NULL if the channel is destroyed before we
2030 * received a sample.
2033 struct channel_state_sample
*sample
= caa_container_of(node
,
2034 struct channel_state_sample
,
2035 channel_state_ht_node
);
2037 cds_lfht_del(state
->channel_state_ht
, node
);
2038 call_rcu(&sample
->rcu_node
, free_channel_state_sample_rcu
);
2041 /* Remove the channel from the channels_ht and free it. */
2042 cds_lfht_lookup(state
->channels_ht
,
2043 hash_channel_key(&key
),
2047 node
= cds_lfht_iter_get_node(&iter
);
2049 channel_info
= caa_container_of(node
, struct channel_info
,
2051 cds_lfht_del(state
->channels_ht
, node
);
2052 channel_info_destroy(channel_info
);
2055 *cmd_result
= LTTNG_OK
;
2060 int handle_notification_thread_command_session_rotation(
2061 struct notification_thread_state
*state
,
2062 enum notification_thread_command_type cmd_type
,
2063 uint64_t session_id
,
2064 uint64_t trace_archive_chunk_id
,
2065 struct lttng_trace_archive_location
*location
,
2066 enum lttng_error_code
*_cmd_result
)
2069 enum lttng_error_code cmd_result
= LTTNG_OK
;
2070 struct lttng_session_trigger_list
*trigger_list
;
2071 struct lttng_trigger_list_element
*trigger_list_element
;
2072 struct session_info
*session_info
;
2073 struct lttng_credentials session_creds
;
2074 struct session_state_sample new_session_state
;
2078 session_info
= get_session_info_by_id(state
, session_id
);
2079 if (!session_info
) {
2080 /* Fatal logic error. */
2081 ERR("Failed to find session while handling rotation state change: session id = %" PRIu64
,
2084 cmd_result
= LTTNG_ERR_FATAL
;
2088 new_session_state
= session_info
->last_state_sample
;
2090 lttng_trace_archive_location_get(location
);
2091 new_session_state
.rotation
.location
= location
;
2093 new_session_state
.rotation
.location
= NULL
;
2097 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session_info
->uid
),
2098 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session_info
->gid
),
2101 new_session_state
.rotation
.ongoing
= cmd_type
==
2102 NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
;
2103 new_session_state
.rotation
.id
= trace_archive_chunk_id
;
2105 trigger_list
= get_session_trigger_list(state
, session_info
->name
);
2106 LTTNG_ASSERT(trigger_list
);
2108 cds_list_for_each_entry(trigger_list_element
, &trigger_list
->list
,
2110 const struct lttng_condition
*condition
;
2111 struct lttng_trigger
*trigger
;
2112 struct notification_client_list
*client_list
;
2113 struct lttng_evaluation
*evaluation
= NULL
;
2114 enum action_executor_status executor_status
;
2116 trigger
= trigger_list_element
->trigger
;
2117 condition
= lttng_trigger_get_const_condition(trigger
);
2118 LTTNG_ASSERT(condition
);
2120 ret
= evaluate_session_condition(
2121 condition
, session_info
, &new_session_state
, &evaluation
);
2124 cmd_result
= LTTNG_ERR_NOMEM
;
2133 * Ownership of `evaluation` transferred to the action executor
2134 * no matter the result. The callee acquires a reference to the
2135 * client list: we can release our own.
2137 client_list
= get_client_list_from_condition(state
, condition
);
2138 executor_status
= action_executor_enqueue_trigger(
2139 state
->executor
, trigger
, evaluation
,
2140 &session_creds
, client_list
);
2141 notification_client_list_put(client_list
);
2143 switch (executor_status
) {
2144 case ACTION_EXECUTOR_STATUS_OK
:
2146 case ACTION_EXECUTOR_STATUS_ERROR
:
2147 case ACTION_EXECUTOR_STATUS_INVALID
:
2149 * TODO Add trigger identification (name/id) when
2150 * it is added to the API.
2152 ERR("Fatal error occurred while enqueuing action associated with session rotation trigger");
2155 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
2157 * TODO Add trigger identification (name/id) when
2158 * it is added to the API.
2160 * Not a fatal error.
2162 WARN("No space left when enqueuing action associated with session rotation trigger");
2172 /* Ownership of new_session_state::location is transferred. */
2173 lttng_trace_archive_location_put(session_info
->last_state_sample
.rotation
.location
);
2174 session_info
->last_state_sample
= new_session_state
;
2177 session_info_put(session_info
);
2178 *_cmd_result
= cmd_result
;
2184 int handle_notification_thread_command_add_tracer_event_source(
2185 struct notification_thread_state
*state
,
2186 int tracer_event_source_fd
,
2187 enum lttng_domain_type domain_type
,
2188 enum lttng_error_code
*_cmd_result
)
2191 enum lttng_error_code cmd_result
= LTTNG_OK
;
2192 struct notification_event_tracer_event_source_element
*element
= NULL
;
2194 element
= zmalloc
<notification_event_tracer_event_source_element
>();
2196 cmd_result
= LTTNG_ERR_NOMEM
;
2201 element
->fd
= tracer_event_source_fd
;
2202 element
->domain
= domain_type
;
2204 cds_list_add(&element
->node
, &state
->tracer_event_sources_list
);
2206 DBG3("Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'",
2207 tracer_event_source_fd
,
2208 lttng_domain_type_str(domain_type
));
2210 /* Adding the read side pipe to the event poll. */
2211 ret
= lttng_poll_add(&state
->events
, tracer_event_source_fd
, LPOLLPRI
| LPOLLIN
);
2213 ERR("Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'",
2214 tracer_event_source_fd
,
2215 lttng_domain_type_str(element
->domain
));
2216 cds_list_del(&element
->node
);
2221 element
->is_fd_in_poll_set
= true;
2224 *_cmd_result
= cmd_result
;
2229 int drain_event_notifier_notification_pipe(
2230 struct notification_thread_state
*state
,
2231 int pipe
, enum lttng_domain_type domain
)
2233 struct lttng_poll_event events
= {};
2236 ret
= lttng_poll_create(&events
, 1, LTTNG_CLOEXEC
);
2238 ERR("Error creating lttng_poll_event");
2242 ret
= lttng_poll_add(&events
, pipe
, LPOLLIN
);
2244 ERR("Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d",
2251 * Continue to consume notifications as long as there are new
2252 * ones coming in. The tracer has been asked to stop producing
2255 * LPOLLIN is explicitly checked since LPOLLHUP is implicitly
2256 * monitored (on Linux, at least) and will be returned when
2257 * the pipe is closed but empty.
2259 ret
= lttng_poll_wait_interruptible(&events
, 0);
2260 if (ret
== 0 || (LTTNG_POLL_GETEV(&events
, 0) & LPOLLIN
) == 0) {
2261 /* No more notification to be read on this pipe. */
2264 } else if (ret
< 0) {
2265 PERROR("Failed on lttng_poll_wait_interruptible() call");
2270 ret
= handle_one_event_notifier_notification(state
, pipe
, domain
);
2272 ERR("Error consuming an event notifier notification from pipe: fd = %d",
2277 lttng_poll_clean(&events
);
2282 struct notification_event_tracer_event_source_element
*
2283 find_tracer_event_source_element(struct notification_thread_state
*state
,
2284 int tracer_event_source_fd
)
2286 struct notification_event_tracer_event_source_element
*source_element
;
2288 cds_list_for_each_entry(source_element
,
2289 &state
->tracer_event_sources_list
, node
) {
2290 if (source_element
->fd
== tracer_event_source_fd
) {
2295 source_element
= NULL
;
2297 return source_element
;
2301 int remove_tracer_event_source_from_pollset(
2302 struct notification_thread_state
*state
,
2303 struct notification_event_tracer_event_source_element
*source_element
)
2307 LTTNG_ASSERT(source_element
->is_fd_in_poll_set
);
2309 DBG3("Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2311 lttng_domain_type_str(source_element
->domain
));
2313 /* Removing the fd from the event poll set. */
2314 ret
= lttng_poll_del(&state
->events
, source_element
->fd
);
2316 ERR("Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2318 lttng_domain_type_str(source_element
->domain
));
2323 source_element
->is_fd_in_poll_set
= false;
2326 * Force the notification thread to restart the poll() loop to ensure
2327 * that any events from the removed fd are removed.
2329 state
->restart_poll
= true;
2331 ret
= drain_event_notifier_notification_pipe(state
, source_element
->fd
,
2332 source_element
->domain
);
2334 ERR("Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s",
2336 lttng_domain_type_str(source_element
->domain
));
2345 int handle_notification_thread_tracer_event_source_died(
2346 struct notification_thread_state
*state
,
2347 int tracer_event_source_fd
)
2350 struct notification_event_tracer_event_source_element
*source_element
;
2352 source_element
= find_tracer_event_source_element(state
,
2353 tracer_event_source_fd
);
2355 LTTNG_ASSERT(source_element
);
2357 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2359 ERR("Failed to remove dead tracer event source from poll set");
2366 int handle_notification_thread_command_remove_tracer_event_source(
2367 struct notification_thread_state
*state
,
2368 int tracer_event_source_fd
,
2369 enum lttng_error_code
*_cmd_result
)
2372 enum lttng_error_code cmd_result
= LTTNG_OK
;
2373 struct notification_event_tracer_event_source_element
*source_element
= NULL
;
2375 source_element
= find_tracer_event_source_element(state
,
2376 tracer_event_source_fd
);
2378 LTTNG_ASSERT(source_element
);
2380 /* Remove the tracer source from the list. */
2381 cds_list_del(&source_element
->node
);
2383 if (!source_element
->is_fd_in_poll_set
) {
2384 /* Skip the poll set removal. */
2388 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2390 ERR("Failed to remove tracer event source from poll set");
2391 cmd_result
= LTTNG_ERR_FATAL
;
2395 free(source_element
);
2396 *_cmd_result
= cmd_result
;
2400 static int handle_notification_thread_command_list_triggers(
2401 struct notification_thread_handle
*handle
__attribute__((unused
)),
2402 struct notification_thread_state
*state
,
2404 struct lttng_triggers
**triggers
,
2405 enum lttng_error_code
*_cmd_result
)
2408 enum lttng_error_code cmd_result
= LTTNG_OK
;
2409 struct cds_lfht_iter iter
;
2410 struct lttng_trigger_ht_element
*trigger_ht_element
;
2411 struct lttng_triggers
*local_triggers
= NULL
;
2412 const struct lttng_credentials
*creds
;
2416 local_triggers
= lttng_triggers_create();
2417 if (!local_triggers
) {
2418 /* Not a fatal error. */
2419 cmd_result
= LTTNG_ERR_NOMEM
;
2423 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
,
2424 trigger_ht_element
, node
) {
2426 * Only return the triggers to which the client has access.
2427 * The root user has visibility over all triggers.
2429 creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
2430 if (client_uid
!= lttng_credentials_get_uid(creds
) && client_uid
!= 0) {
2434 ret
= lttng_triggers_add(local_triggers
,
2435 trigger_ht_element
->trigger
);
2437 /* Not a fatal error. */
2439 cmd_result
= LTTNG_ERR_NOMEM
;
2444 /* Transferring ownership to the caller. */
2445 *triggers
= local_triggers
;
2446 local_triggers
= NULL
;
2450 lttng_triggers_destroy(local_triggers
);
2451 *_cmd_result
= cmd_result
;
2455 static inline void get_trigger_info_for_log(const struct lttng_trigger
*trigger
,
2456 const char **trigger_name
,
2457 uid_t
*trigger_owner_uid
)
2459 enum lttng_trigger_status trigger_status
;
2461 trigger_status
= lttng_trigger_get_name(trigger
, trigger_name
);
2462 switch (trigger_status
) {
2463 case LTTNG_TRIGGER_STATUS_OK
:
2465 case LTTNG_TRIGGER_STATUS_UNSET
:
2466 *trigger_name
= "(anonymous)";
2472 trigger_status
= lttng_trigger_get_owner_uid(trigger
,
2474 LTTNG_ASSERT(trigger_status
== LTTNG_TRIGGER_STATUS_OK
);
2477 static int handle_notification_thread_command_get_trigger(
2478 struct notification_thread_state
*state
,
2479 const struct lttng_trigger
*trigger
,
2480 struct lttng_trigger
**registered_trigger
,
2481 enum lttng_error_code
*_cmd_result
)
2484 struct cds_lfht_iter iter
;
2485 struct lttng_trigger_ht_element
*trigger_ht_element
;
2486 enum lttng_error_code cmd_result
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
2487 const char *trigger_name
;
2488 uid_t trigger_owner_uid
;
2492 cds_lfht_for_each_entry(
2493 state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
2494 if (lttng_trigger_is_equal(
2495 trigger
, trigger_ht_element
->trigger
)) {
2496 /* Take one reference on the return trigger. */
2497 *registered_trigger
= trigger_ht_element
->trigger
;
2498 lttng_trigger_get(*registered_trigger
);
2500 cmd_result
= LTTNG_OK
;
2505 /* Not a fatal error if the trigger is not found. */
2506 get_trigger_info_for_log(trigger
, &trigger_name
, &trigger_owner_uid
);
2507 DBG("Failed to retrieve registered version of trigger: trigger name = '%s', trigger owner uid = %d",
2508 trigger_name
, (int) trigger_owner_uid
);
2514 *_cmd_result
= cmd_result
;
2519 bool condition_is_supported(struct lttng_condition
*condition
)
2523 switch (lttng_condition_get_type(condition
)) {
2524 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
2525 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
2528 enum lttng_domain_type domain
;
2530 ret
= lttng_condition_buffer_usage_get_domain_type(condition
,
2532 LTTNG_ASSERT(ret
== 0);
2534 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2535 is_supported
= true;
2540 * Older kernel tracers don't expose the API to monitor their
2541 * buffers. Therefore, we reject triggers that require that
2542 * mechanism to be available to be evaluated.
2544 * Assume unsupported on error.
2546 is_supported
= kernel_supports_ring_buffer_snapshot_sample_positions() == 1;
2549 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
2551 const struct lttng_event_rule
*event_rule
;
2552 enum lttng_domain_type domain
;
2553 const enum lttng_condition_status status
=
2554 lttng_condition_event_rule_matches_get_rule(
2555 condition
, &event_rule
);
2557 LTTNG_ASSERT(status
== LTTNG_CONDITION_STATUS_OK
);
2559 domain
= lttng_event_rule_get_domain_type(event_rule
);
2560 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2561 is_supported
= true;
2566 * Older kernel tracers can't emit notification. Therefore, we
2567 * reject triggers that require that mechanism to be available
2570 * Assume unsupported on error.
2572 is_supported
= kernel_supports_event_notifiers() == 1;
2576 is_supported
= true;
2579 return is_supported
;
2582 /* Must be called with RCU read lock held. */
2584 int bind_trigger_to_matching_session(struct lttng_trigger
*trigger
,
2585 struct notification_thread_state
*state
)
2588 const struct lttng_condition
*condition
;
2589 const char *session_name
;
2590 struct lttng_session_trigger_list
*trigger_list
;
2592 ASSERT_RCU_READ_LOCKED();
2594 condition
= lttng_trigger_get_const_condition(trigger
);
2595 session_name
= get_condition_session_name(condition
);
2597 trigger_list
= get_session_trigger_list(state
, session_name
);
2598 if (!trigger_list
) {
2599 DBG("Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system",
2605 DBG("Newly registered trigger bound to session \"%s\"",
2607 ret
= lttng_session_trigger_list_add(trigger_list
, trigger
);
2612 /* Must be called with RCU read lock held. */
2614 int bind_trigger_to_matching_channels(struct lttng_trigger
*trigger
,
2615 struct notification_thread_state
*state
)
2618 struct cds_lfht_node
*node
;
2619 struct cds_lfht_iter iter
;
2620 struct channel_info
*channel
;
2622 ASSERT_RCU_READ_LOCKED();
2624 cds_lfht_for_each_entry(state
->channels_ht
, &iter
, channel
,
2626 struct lttng_trigger_list_element
*trigger_list_element
;
2627 struct lttng_channel_trigger_list
*trigger_list
;
2628 struct cds_lfht_iter lookup_iter
;
2630 if (!trigger_applies_to_channel(trigger
, channel
)) {
2634 cds_lfht_lookup(state
->channel_triggers_ht
,
2635 hash_channel_key(&channel
->key
),
2636 match_channel_trigger_list
,
2639 node
= cds_lfht_iter_get_node(&lookup_iter
);
2641 trigger_list
= caa_container_of(node
,
2642 struct lttng_channel_trigger_list
,
2643 channel_triggers_ht_node
);
2645 trigger_list_element
= zmalloc
<lttng_trigger_list_element
>();
2646 if (!trigger_list_element
) {
2650 CDS_INIT_LIST_HEAD(&trigger_list_element
->node
);
2651 trigger_list_element
->trigger
= trigger
;
2652 cds_list_add(&trigger_list_element
->node
, &trigger_list
->list
);
2653 DBG("Newly registered trigger bound to channel \"%s\"",
2661 bool is_trigger_action_notify(const struct lttng_trigger
*trigger
)
2663 bool is_notify
= false;
2664 unsigned int i
, count
;
2665 enum lttng_action_status action_status
;
2666 const struct lttng_action
*action
=
2667 lttng_trigger_get_const_action(trigger
);
2668 enum lttng_action_type action_type
;
2670 LTTNG_ASSERT(action
);
2671 action_type
= lttng_action_get_type(action
);
2672 if (action_type
== LTTNG_ACTION_TYPE_NOTIFY
) {
2675 } else if (action_type
!= LTTNG_ACTION_TYPE_LIST
) {
2679 action_status
= lttng_action_list_get_count(action
, &count
);
2680 LTTNG_ASSERT(action_status
== LTTNG_ACTION_STATUS_OK
);
2682 for (i
= 0; i
< count
; i
++) {
2683 const struct lttng_action
*inner_action
=
2684 lttng_action_list_get_at_index(
2687 action_type
= lttng_action_get_type(inner_action
);
2688 if (action_type
== LTTNG_ACTION_TYPE_NOTIFY
) {
2698 static bool trigger_name_taken(struct notification_thread_state
*state
,
2699 const struct lttng_trigger
*trigger
)
2701 struct cds_lfht_iter iter
;
2704 * No duplicata is allowed in the triggers_by_name_uid_ht.
2705 * The match is done against the trigger name and uid.
2707 cds_lfht_lookup(state
->triggers_by_name_uid_ht
,
2708 hash_trigger_by_name_uid(trigger
),
2709 match_trigger_by_name_uid
,
2712 return !!cds_lfht_iter_get_node(&iter
);
2716 enum lttng_error_code
generate_trigger_name(
2717 struct notification_thread_state
*state
,
2718 struct lttng_trigger
*trigger
, const char **name
)
2720 enum lttng_error_code ret_code
= LTTNG_OK
;
2722 enum lttng_trigger_status status
;
2725 const int ret
= lttng_trigger_generate_name(trigger
,
2726 state
->trigger_id
.name_offset
++);
2728 /* The only reason this can fail right now. */
2729 ret_code
= LTTNG_ERR_NOMEM
;
2733 status
= lttng_trigger_get_name(trigger
, name
);
2734 LTTNG_ASSERT(status
== LTTNG_TRIGGER_STATUS_OK
);
2736 taken
= trigger_name_taken(state
, trigger
);
2737 } while (taken
|| state
->trigger_id
.name_offset
== UINT64_MAX
);
2743 void notif_thread_state_remove_trigger_ht_elem(
2744 struct notification_thread_state
*state
,
2745 struct lttng_trigger_ht_element
*trigger_ht_element
)
2747 LTTNG_ASSERT(state
);
2748 LTTNG_ASSERT(trigger_ht_element
);
2750 cds_lfht_del(state
->triggers_ht
, &trigger_ht_element
->node
);
2751 cds_lfht_del(state
->triggers_by_name_uid_ht
, &trigger_ht_element
->node_by_name_uid
);
2755 enum lttng_error_code
setup_tracer_notifier(
2756 struct notification_thread_state
*state
,
2757 struct lttng_trigger
*trigger
)
2759 enum lttng_error_code ret
;
2760 enum event_notifier_error_accounting_status error_accounting_status
;
2761 struct cds_lfht_node
*node
;
2762 uint64_t error_counter_index
= 0;
2763 struct lttng_condition
*condition
= lttng_trigger_get_condition(trigger
);
2764 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
= NULL
;
2766 trigger_tokens_ht_element
= zmalloc
<notification_trigger_tokens_ht_element
>();
2767 if (!trigger_tokens_ht_element
) {
2768 ret
= LTTNG_ERR_NOMEM
;
2772 /* Add trigger token to the trigger_tokens_ht. */
2773 cds_lfht_node_init(&trigger_tokens_ht_element
->node
);
2774 trigger_tokens_ht_element
->token
= LTTNG_OPTIONAL_GET(trigger
->tracer_token
);
2775 trigger_tokens_ht_element
->trigger
= trigger
;
2777 node
= cds_lfht_add_unique(state
->trigger_tokens_ht
,
2778 hash_key_u64(&trigger_tokens_ht_element
->token
, lttng_ht_seed
),
2779 match_trigger_token
,
2780 &trigger_tokens_ht_element
->token
,
2781 &trigger_tokens_ht_element
->node
);
2782 if (node
!= &trigger_tokens_ht_element
->node
) {
2783 ret
= LTTNG_ERR_TRIGGER_EXISTS
;
2784 goto error_free_ht_element
;
2787 error_accounting_status
= event_notifier_error_accounting_register_event_notifier(
2788 trigger
, &error_counter_index
);
2789 if (error_accounting_status
!= EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK
) {
2790 if (error_accounting_status
== EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE
) {
2791 DBG("Trigger list error accounting counter full.");
2792 ret
= LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING_FULL
;
2794 ERR("Error registering trigger for error accounting");
2795 ret
= LTTNG_ERR_EVENT_NOTIFIER_REGISTRATION
;
2798 goto error_remove_ht_element
;
2801 lttng_condition_event_rule_matches_set_error_counter_index(
2802 condition
, error_counter_index
);
2807 error_remove_ht_element
:
2808 cds_lfht_del(state
->trigger_tokens_ht
, &trigger_tokens_ht_element
->node
);
2809 error_free_ht_element
:
2810 free(trigger_tokens_ht_element
);
2816 * FIXME A client's credentials are not checked when registering a trigger.
2818 * The effects of this are benign since:
2819 * - The client will succeed in registering the trigger, as it is valid,
2820 * - The trigger will, internally, be bound to the channel/session,
2821 * - The notifications will not be sent since the client's credentials
2822 * are checked against the channel at that moment.
2824 * If this function returns a non-zero value, it means something is
2825 * fundamentally broken and the whole subsystem/thread will be torn down.
2827 * If a non-fatal error occurs, just set the cmd_result to the appropriate
2831 int handle_notification_thread_command_register_trigger(
2832 struct notification_thread_state
*state
,
2833 struct lttng_trigger
*trigger
,
2834 bool is_trigger_anonymous
,
2835 enum lttng_error_code
*cmd_result
)
2838 struct lttng_condition
*condition
;
2839 struct notification_client_list
*client_list
= NULL
;
2840 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
2841 struct cds_lfht_node
*node
;
2842 const char* trigger_name
;
2843 bool free_trigger
= true;
2844 struct lttng_evaluation
*evaluation
= NULL
;
2845 struct lttng_credentials object_creds
;
2848 enum action_executor_status executor_status
;
2849 const uint64_t trigger_tracer_token
=
2850 state
->trigger_id
.next_tracer_token
++;
2854 /* Set the trigger's tracer token. */
2855 lttng_trigger_set_tracer_token(trigger
, trigger_tracer_token
);
2857 if (!is_trigger_anonymous
) {
2858 if (lttng_trigger_get_name(trigger
, &trigger_name
) ==
2859 LTTNG_TRIGGER_STATUS_UNSET
) {
2860 const enum lttng_error_code ret_code
=
2861 generate_trigger_name(state
, trigger
,
2864 if (ret_code
!= LTTNG_OK
) {
2867 *cmd_result
= ret_code
;
2870 } else if (trigger_name_taken(state
, trigger
)) {
2871 /* Not a fatal error. */
2872 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2877 trigger_name
= "(anonymous)";
2880 condition
= lttng_trigger_get_condition(trigger
);
2881 LTTNG_ASSERT(condition
);
2883 /* Some conditions require tracers to implement a minimal ABI version. */
2884 if (!condition_is_supported(condition
)) {
2885 *cmd_result
= LTTNG_ERR_NOT_SUPPORTED
;
2889 trigger_ht_element
= zmalloc
<lttng_trigger_ht_element
>();
2890 if (!trigger_ht_element
) {
2895 /* Add trigger to the trigger_ht. */
2896 cds_lfht_node_init(&trigger_ht_element
->node
);
2897 cds_lfht_node_init(&trigger_ht_element
->node_by_name_uid
);
2898 trigger_ht_element
->trigger
= trigger
;
2900 node
= cds_lfht_add_unique(state
->triggers_ht
,
2901 lttng_condition_hash(condition
),
2904 &trigger_ht_element
->node
);
2905 if (node
!= &trigger_ht_element
->node
) {
2906 /* Not a fatal error, simply report it to the client. */
2907 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2908 goto error_free_ht_element
;
2911 node
= cds_lfht_add_unique(state
->triggers_by_name_uid_ht
,
2912 hash_trigger_by_name_uid(trigger
),
2913 match_trigger_by_name_uid
,
2915 &trigger_ht_element
->node_by_name_uid
);
2916 if (node
!= &trigger_ht_element
->node_by_name_uid
) {
2917 /* Internal error: add to triggers_ht should have failed. */
2919 goto error_free_ht_element
;
2922 /* From this point consider the trigger registered. */
2923 lttng_trigger_set_as_registered(trigger
);
2926 * Some triggers might need a tracer notifier depending on its
2927 * condition and actions.
2929 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
2930 enum lttng_error_code error_code
;
2932 error_code
= setup_tracer_notifier(state
, trigger
);
2933 if (error_code
!= LTTNG_OK
) {
2934 notif_thread_state_remove_trigger_ht_elem(state
,
2935 trigger_ht_element
);
2936 if (error_code
== LTTNG_ERR_NOMEM
) {
2939 *cmd_result
= error_code
;
2943 goto error_free_ht_element
;
2948 * The rest only applies to triggers that have a "notify" action.
2949 * It is not skipped as this is the only action type currently
2952 if (is_trigger_action_notify(trigger
)) {
2954 * Find or create the client list of this condition. It may
2955 * already be present if another trigger is already registered
2956 * with the same condition.
2958 client_list
= get_client_list_from_condition(state
, condition
);
2961 * No client list for this condition yet. We create new
2962 * one and build it up.
2964 client_list
= notification_client_list_create(state
, condition
);
2966 ERR("Error creating notification client list for trigger %s", trigger
->name
);
2968 goto error_free_ht_element
;
2972 CDS_INIT_LIST_HEAD(&trigger_ht_element
->client_list_trigger_node
);
2974 pthread_mutex_lock(&client_list
->lock
);
2975 cds_list_add(&trigger_ht_element
->client_list_trigger_node
, &client_list
->triggers_list
);
2976 pthread_mutex_unlock(&client_list
->lock
);
2980 * Ownership of the trigger and of its wrapper was transfered to
2981 * the triggers_ht. Same for token ht element if necessary.
2983 trigger_ht_element
= NULL
;
2984 free_trigger
= false;
2986 switch (get_condition_binding_object(condition
)) {
2987 case LTTNG_OBJECT_TYPE_SESSION
:
2988 /* Add the trigger to the list if it matches a known session. */
2989 ret
= bind_trigger_to_matching_session(trigger
, state
);
2991 goto error_free_ht_element
;
2994 case LTTNG_OBJECT_TYPE_CHANNEL
:
2996 * Add the trigger to list of triggers bound to the channels
2999 ret
= bind_trigger_to_matching_channels(trigger
, state
);
3001 goto error_free_ht_element
;
3004 case LTTNG_OBJECT_TYPE_NONE
:
3007 ERR("Unknown object type on which to bind a newly registered trigger was encountered");
3009 goto error_free_ht_element
;
3013 * The new trigger's condition must be evaluated against the current
3016 * In the case of `notify` action, nothing preventing clients from
3017 * subscribing to a condition before the corresponding trigger is
3018 * registered, we have to evaluate this new condition right away.
3020 * At some point, we were waiting for the next "evaluation" (e.g. on
3021 * reception of a channel sample) to evaluate this new condition, but
3024 * The reason it was broken is that waiting for the next sample
3025 * does not allow us to properly handle transitions for edge-triggered
3028 * Consider this example: when we handle a new channel sample, we
3029 * evaluate each conditions twice: once with the previous state, and
3030 * again with the newest state. We then use those two results to
3031 * determine whether a state change happened: a condition was false and
3032 * became true. If a state change happened, we have to notify clients.
3034 * Now, if a client subscribes to a given notification and registers
3035 * a trigger *after* that subscription, we have to make sure the
3036 * condition is evaluated at this point while considering only the
3037 * current state. Otherwise, the next evaluation cycle may only see
3038 * that the evaluations remain the same (true for samples n-1 and n) and
3039 * the client will never know that the condition has been met.
3041 switch (get_condition_binding_object(condition
)) {
3042 case LTTNG_OBJECT_TYPE_SESSION
:
3044 /* Find the session associated with the condition. */
3045 const auto *session_name
= get_condition_session_name(condition
);
3046 auto session_info
= get_session_info_by_name(state
, session_name
);
3047 if (!session_info
) {
3048 /* Not an error, the session doesn't exist yet. */
3049 DBG("Session not found while evaluating session condition during registration of trigger: session name = `%s`",
3055 LTTNG_OPTIONAL_SET(&object_creds
.uid
, session_info
->uid
);
3056 LTTNG_OPTIONAL_SET(&object_creds
.gid
, session_info
->gid
);
3058 ret
= evaluate_session_condition(condition
, session_info
, NULL
, &evaluation
);
3059 session_info_put(session_info
);
3062 case LTTNG_OBJECT_TYPE_CHANNEL
:
3063 ret
= evaluate_channel_condition_for_client(condition
, state
,
3064 &evaluation
, &object_uid
,
3066 LTTNG_OPTIONAL_SET(&object_creds
.uid
, object_uid
);
3067 LTTNG_OPTIONAL_SET(&object_creds
.gid
, object_gid
);
3069 case LTTNG_OBJECT_TYPE_NONE
:
3072 case LTTNG_OBJECT_TYPE_UNKNOWN
:
3080 goto error_free_ht_element
;
3083 DBG("Newly registered trigger's condition evaluated to %s",
3084 evaluation
? "true" : "false");
3086 /* Evaluation yielded nothing. Normal exit. */
3092 * Ownership of `evaluation` transferred to the action executor
3093 * no matter the result.
3095 executor_status
= action_executor_enqueue_trigger(state
->executor
,
3096 trigger
, evaluation
, &object_creds
, client_list
);
3098 switch (executor_status
) {
3099 case ACTION_EXECUTOR_STATUS_OK
:
3101 case ACTION_EXECUTOR_STATUS_ERROR
:
3102 case ACTION_EXECUTOR_STATUS_INVALID
:
3104 * TODO Add trigger identification (name/id) when
3105 * it is added to the API.
3107 ERR("Fatal error occurred while enqueuing action associated to newly registered trigger");
3109 goto error_free_ht_element
;
3110 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
3112 * TODO Add trigger identification (name/id) when
3113 * it is added to the API.
3115 * Not a fatal error.
3117 WARN("No space left when enqueuing action associated to newly registered trigger");
3125 *cmd_result
= LTTNG_OK
;
3126 DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64
,
3127 trigger_name
, trigger_tracer_token
);
3130 error_free_ht_element
:
3131 if (trigger_ht_element
) {
3132 /* Delayed removal due to RCU constraint on delete. */
3133 call_rcu(&trigger_ht_element
->rcu_node
,
3134 free_lttng_trigger_ht_element_rcu
);
3139 * Other objects might have a reference to the trigger, mark it
3142 lttng_trigger_set_as_unregistered(trigger
);
3143 lttng_trigger_destroy(trigger
);
3151 void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
)
3153 free(caa_container_of(node
, struct lttng_trigger_ht_element
,
3158 void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head
*node
)
3160 free(caa_container_of(node
, struct notification_trigger_tokens_ht_element
,
3165 void teardown_tracer_notifier(struct notification_thread_state
*state
,
3166 const struct lttng_trigger
*trigger
)
3168 struct cds_lfht_iter iter
;
3169 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
;
3171 cds_lfht_for_each_entry(state
->trigger_tokens_ht
, &iter
,
3172 trigger_tokens_ht_element
, node
) {
3174 if (!lttng_trigger_is_equal(trigger
,
3175 trigger_tokens_ht_element
->trigger
)) {
3179 event_notifier_error_accounting_unregister_event_notifier(
3180 trigger_tokens_ht_element
->trigger
);
3182 /* TODO talk to all app and remove it */
3183 DBG("Removed trigger from tokens_ht");
3184 cds_lfht_del(state
->trigger_tokens_ht
,
3185 &trigger_tokens_ht_element
->node
);
3187 call_rcu(&trigger_tokens_ht_element
->rcu_node
,
3188 free_notification_trigger_tokens_ht_element_rcu
);
3195 void remove_trigger_from_session_trigger_list(
3196 struct lttng_session_trigger_list
*trigger_list
,
3197 const struct lttng_trigger
*trigger
)
3200 struct lttng_trigger_list_element
*trigger_element
, *tmp
;
3202 cds_list_for_each_entry_safe (trigger_element
, tmp
, &trigger_list
->list
, node
) {
3203 if (!lttng_trigger_is_equal(trigger
, trigger_element
->trigger
)) {
3207 DBG("Removed trigger from session_triggers_ht");
3208 cds_list_del(&trigger_element
->node
);
3209 free(trigger_element
);
3210 /* A trigger can only appear once per session. */
3216 ERR("Failed to find trigger associated with session: session name = `%s`",
3217 trigger_list
->session_name
);
3220 LTTNG_ASSERT(found
);
3224 int handle_notification_thread_command_unregister_trigger(
3225 struct notification_thread_state
*state
,
3226 const struct lttng_trigger
*trigger
,
3227 enum lttng_error_code
*_cmd_reply
)
3229 struct cds_lfht_iter iter
;
3230 struct cds_lfht_node
*triggers_ht_node
;
3231 struct notification_client_list
*client_list
;
3232 struct lttng_trigger_ht_element
*trigger_ht_element
= NULL
;
3233 const struct lttng_condition
*condition
= lttng_trigger_get_const_condition(
3235 enum lttng_error_code cmd_reply
;
3239 cds_lfht_lookup(state
->triggers_ht
,
3240 lttng_condition_hash(condition
),
3244 triggers_ht_node
= cds_lfht_iter_get_node(&iter
);
3245 if (!triggers_ht_node
) {
3246 cmd_reply
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
3249 cmd_reply
= LTTNG_OK
;
3252 trigger_ht_element
= caa_container_of(triggers_ht_node
,
3253 struct lttng_trigger_ht_element
, node
);
3255 switch (get_condition_binding_object(condition
)) {
3256 case LTTNG_OBJECT_TYPE_CHANNEL
:
3258 struct lttng_channel_trigger_list
*trigger_list
;
3261 * Remove trigger from channel_triggers_ht.
3263 * Note that multiple channels may have matched the trigger's
3264 * condition (e.g. all instances of a given channel in per-pid buffering
3267 * Iterate on all lists since we don't know the target channels' keys.
3269 cds_lfht_for_each_entry(state
->channel_triggers_ht
, &iter
, trigger_list
,
3270 channel_triggers_ht_node
) {
3271 struct lttng_trigger_list_element
*trigger_element
, *tmp
;
3273 cds_list_for_each_entry_safe(
3274 trigger_element
, tmp
, &trigger_list
->list
, node
) {
3275 if (!lttng_trigger_is_equal(trigger
, trigger_element
->trigger
)) {
3279 DBG("Removed trigger from channel_triggers_ht");
3280 cds_list_del(&trigger_element
->node
);
3281 free(trigger_element
);
3282 /* A trigger can only appear once per channel */
3288 case LTTNG_OBJECT_TYPE_SESSION
:
3290 auto session
= get_session_info_by_name(
3291 state
, get_condition_session_name(condition
));
3293 /* Session doesn't exist, no trigger to remove. */
3298 auto session_trigger_list
= get_session_trigger_list(state
, session
->name
);
3299 remove_trigger_from_session_trigger_list(session_trigger_list
, trigger
);
3300 session_info_put(session
);
3302 case LTTNG_OBJECT_TYPE_NONE
:
3308 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
3309 teardown_tracer_notifier(state
, trigger
);
3312 if (is_trigger_action_notify(trigger
)) {
3314 * Remove and release the client list from
3315 * notification_trigger_clients_ht.
3317 client_list
= get_client_list_from_condition(state
, condition
);
3318 LTTNG_ASSERT(client_list
);
3320 pthread_mutex_lock(&client_list
->lock
);
3321 cds_list_del(&trigger_ht_element
->client_list_trigger_node
);
3322 pthread_mutex_unlock(&client_list
->lock
);
3324 /* Put new reference and the hashtable's reference. */
3325 notification_client_list_put(client_list
);
3326 notification_client_list_put(client_list
);
3330 /* Remove trigger from triggers_ht. */
3331 notif_thread_state_remove_trigger_ht_elem(state
, trigger_ht_element
);
3333 /* Release the ownership of the trigger. */
3334 lttng_trigger_destroy(trigger_ht_element
->trigger
);
3335 call_rcu(&trigger_ht_element
->rcu_node
, free_lttng_trigger_ht_element_rcu
);
3339 *_cmd_reply
= cmd_reply
;
3345 int pop_cmd_queue(struct notification_thread_handle
*handle
,
3346 struct notification_thread_command
**cmd
)
3351 pthread_mutex_lock(&handle
->cmd_queue
.lock
);
3352 ret
= lttng_read(handle
->cmd_queue
.event_fd
, &counter
, sizeof(counter
));
3353 if (ret
!= sizeof(counter
)) {
3358 *cmd
= cds_list_first_entry(&handle
->cmd_queue
.list
,
3359 struct notification_thread_command
, cmd_list_node
);
3360 cds_list_del(&((*cmd
)->cmd_list_node
));
3364 pthread_mutex_unlock(&handle
->cmd_queue
.lock
);
3368 /* Returns 0 on success, 1 on exit requested, negative value on error. */
3369 int handle_notification_thread_command(
3370 struct notification_thread_handle
*handle
,
3371 struct notification_thread_state
*state
)
3374 struct notification_thread_command
*cmd
;
3376 ret
= pop_cmd_queue(handle
, &cmd
);
3381 DBG("Received `%s` command",
3382 notification_command_type_str(cmd
->type
));
3383 switch (cmd
->type
) {
3384 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
3385 ret
= handle_notification_thread_command_register_trigger(state
,
3386 cmd
->parameters
.register_trigger
.trigger
,
3387 cmd
->parameters
.register_trigger
.is_trigger_anonymous
,
3390 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
3391 ret
= handle_notification_thread_command_unregister_trigger(
3393 cmd
->parameters
.unregister_trigger
.trigger
,
3396 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
3397 ret
= handle_notification_thread_command_add_channel(
3399 cmd
->parameters
.add_channel
.session
.id
,
3400 cmd
->parameters
.add_channel
.channel
.name
,
3401 cmd
->parameters
.add_channel
.channel
.domain
,
3402 cmd
->parameters
.add_channel
.channel
.key
,
3403 cmd
->parameters
.add_channel
.channel
.capacity
,
3406 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
3407 ret
= handle_notification_thread_command_remove_channel(
3408 state
, cmd
->parameters
.remove_channel
.key
,
3409 cmd
->parameters
.remove_channel
.domain
,
3412 case NOTIFICATION_COMMAND_TYPE_ADD_SESSION
:
3413 ret
= handle_notification_thread_command_add_session(state
,
3414 cmd
->parameters
.add_session
.session_id
,
3415 cmd
->parameters
.add_session
.session_name
,
3416 cmd
->parameters
.add_session
.session_uid
,
3417 cmd
->parameters
.add_session
.session_gid
, &cmd
->reply_code
);
3419 case NOTIFICATION_COMMAND_TYPE_REMOVE_SESSION
:
3420 ret
= handle_notification_thread_command_remove_session(
3421 state
, cmd
->parameters
.remove_session
.session_id
, &cmd
->reply_code
);
3423 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
3424 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
3425 ret
= handle_notification_thread_command_session_rotation(
3428 cmd
->parameters
.session_rotation
.session_id
,
3429 cmd
->parameters
.session_rotation
.trace_archive_chunk_id
,
3430 cmd
->parameters
.session_rotation
.location
,
3433 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
3434 ret
= handle_notification_thread_command_add_tracer_event_source(
3436 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3437 cmd
->parameters
.tracer_event_source
.domain
,
3440 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
3441 ret
= handle_notification_thread_command_remove_tracer_event_source(
3443 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3446 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
3448 struct lttng_triggers
*triggers
= NULL
;
3450 ret
= handle_notification_thread_command_list_triggers(
3453 cmd
->parameters
.list_triggers
.uid
,
3456 cmd
->reply
.list_triggers
.triggers
= triggers
;
3460 case NOTIFICATION_COMMAND_TYPE_QUIT
:
3461 cmd
->reply_code
= LTTNG_OK
;
3464 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
3466 struct lttng_trigger
*trigger
= NULL
;
3468 ret
= handle_notification_thread_command_get_trigger(state
,
3469 cmd
->parameters
.get_trigger
.trigger
, &trigger
,
3471 cmd
->reply
.get_trigger
.trigger
= trigger
;
3474 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
3476 const enum client_transmission_status client_status
=
3477 cmd
->parameters
.client_communication_update
3479 const notification_client_id client_id
=
3480 cmd
->parameters
.client_communication_update
.id
;
3481 struct notification_client
*client
;
3484 client
= get_client_from_id(client_id
, state
);
3488 * Client error was probably already picked-up by the
3489 * notification thread or it has disconnected
3490 * gracefully while this command was queued.
3492 DBG("Failed to find notification client to update communication status, client id = %" PRIu64
,
3496 ret
= client_handle_transmission_status(
3497 client
, client_status
, state
);
3503 ERR("Unknown internal command received");
3511 if (cmd
->is_async
) {
3515 lttng_waiter_wake_up(&cmd
->reply_waiter
);
3519 /* Wake-up and return a fatal error to the calling thread. */
3520 lttng_waiter_wake_up(&cmd
->reply_waiter
);
3521 cmd
->reply_code
= LTTNG_ERR_FATAL
;
3523 /* Indicate a fatal error to the caller. */
3528 int socket_set_non_blocking(int socket
)
3532 /* Set the pipe as non-blocking. */
3533 ret
= fcntl(socket
, F_GETFL
, 0);
3535 PERROR("fcntl get socket flags");
3540 ret
= fcntl(socket
, F_SETFL
, flags
| O_NONBLOCK
);
3542 PERROR("fcntl set O_NONBLOCK socket flag");
3545 DBG("Client socket (fd = %i) set as non-blocking", socket
);
3551 int client_reset_inbound_state(struct notification_client
*client
)
3556 lttng_payload_clear(&client
->communication
.inbound
.payload
);
3558 client
->communication
.inbound
.bytes_to_receive
=
3559 sizeof(struct lttng_notification_channel_message
);
3560 client
->communication
.inbound
.msg_type
=
3561 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
;
3562 LTTNG_SOCK_SET_UID_CRED(&client
->communication
.inbound
.creds
, -1);
3563 LTTNG_SOCK_SET_GID_CRED(&client
->communication
.inbound
.creds
, -1);
3564 ret
= lttng_dynamic_buffer_set_size(
3565 &client
->communication
.inbound
.payload
.buffer
,
3566 client
->communication
.inbound
.bytes_to_receive
);
3571 int handle_notification_thread_client_connect(
3572 struct notification_thread_state
*state
)
3575 struct notification_client
*client
;
3577 DBG("Handling new notification channel client connection");
3579 client
= zmalloc
<notification_client
>();
3586 pthread_mutex_init(&client
->lock
, NULL
);
3587 client
->id
= state
->next_notification_client_id
++;
3588 CDS_INIT_LIST_HEAD(&client
->condition_list
);
3589 lttng_payload_init(&client
->communication
.inbound
.payload
);
3590 lttng_payload_init(&client
->communication
.outbound
.payload
);
3591 client
->communication
.inbound
.expect_creds
= true;
3593 ret
= client_reset_inbound_state(client
);
3595 ERR("Failed to reset client communication's inbound state");
3600 ret
= lttcomm_accept_unix_sock(state
->notification_channel_socket
);
3602 ERR("Failed to accept new notification channel client connection");
3607 client
->socket
= ret
;
3609 ret
= socket_set_non_blocking(client
->socket
);
3611 ERR("Failed to set new notification channel client connection socket as non-blocking");
3615 ret
= lttcomm_setsockopt_creds_unix_sock(client
->socket
);
3617 ERR("Failed to set socket options on new notification channel client socket");
3622 client
->communication
.current_poll_events
= CLIENT_POLL_EVENTS_IN
;
3623 ret
= lttng_poll_add(&state
->events
, client
->socket
,
3624 client
->communication
.current_poll_events
);
3626 ERR("Failed to add notification channel client socket to poll set");
3630 DBG("Added new notification channel client socket (%i) to poll set",
3634 cds_lfht_add(state
->client_socket_ht
,
3635 hash_client_socket(client
->socket
),
3636 &client
->client_socket_ht_node
);
3637 cds_lfht_add(state
->client_id_ht
,
3638 hash_client_id(client
->id
),
3639 &client
->client_id_ht_node
);
3645 notification_client_destroy(client
);
3650 * RCU read-lock must be held by the caller.
3651 * Client lock must _not_ be held by the caller.
3654 int notification_thread_client_disconnect(
3655 struct notification_client
*client
,
3656 struct notification_thread_state
*state
)
3659 struct lttng_condition_list_element
*condition_list_element
, *tmp
;
3661 ASSERT_RCU_READ_LOCKED();
3663 /* Acquire the client lock to disable its communication atomically. */
3664 pthread_mutex_lock(&client
->lock
);
3665 client
->communication
.active
= false;
3666 cds_lfht_del(state
->client_socket_ht
, &client
->client_socket_ht_node
);
3667 cds_lfht_del(state
->client_id_ht
, &client
->client_id_ht_node
);
3668 pthread_mutex_unlock(&client
->lock
);
3670 ret
= lttng_poll_del(&state
->events
, client
->socket
);
3672 ERR("Failed to remove client socket %d from poll set",
3676 /* Release all conditions to which the client was subscribed. */
3677 cds_list_for_each_entry_safe(condition_list_element
, tmp
,
3678 &client
->condition_list
, node
) {
3679 (void) notification_thread_client_unsubscribe(client
,
3680 condition_list_element
->condition
, state
, NULL
);
3684 * Client no longer accessible to other threads (through the
3687 notification_client_destroy(client
);
3691 int handle_notification_thread_client_disconnect(
3692 int client_socket
, struct notification_thread_state
*state
)
3695 struct notification_client
*client
;
3698 DBG("Closing client connection (socket fd = %i)",
3700 client
= get_client_from_socket(client_socket
, state
);
3702 /* Internal state corruption, fatal error. */
3703 ERR("Unable to find client (socket fd = %i)",
3709 ret
= notification_thread_client_disconnect(client
, state
);
3715 int handle_notification_thread_client_disconnect_all(
3716 struct notification_thread_state
*state
)
3718 struct cds_lfht_iter iter
;
3719 struct notification_client
*client
;
3720 bool error_encoutered
= false;
3723 DBG("Closing all client connections");
3724 cds_lfht_for_each_entry(state
->client_socket_ht
, &iter
, client
,
3725 client_socket_ht_node
) {
3728 ret
= notification_thread_client_disconnect(
3731 error_encoutered
= true;
3735 return error_encoutered
? 1 : 0;
3738 int handle_notification_thread_trigger_unregister_all(
3739 struct notification_thread_state
*state
)
3741 bool error_occurred
= false;
3742 struct cds_lfht_iter iter
;
3743 struct lttng_trigger_ht_element
*trigger_ht_element
;
3746 cds_lfht_for_each_entry(state
->triggers_ht
, &iter
, trigger_ht_element
,
3748 int ret
= handle_notification_thread_command_unregister_trigger(
3749 state
, trigger_ht_element
->trigger
, NULL
);
3751 error_occurred
= true;
3755 return error_occurred
? -1 : 0;
3759 bool client_has_outbound_data_left(
3760 const struct notification_client
*client
)
3762 const struct lttng_payload_view pv
= lttng_payload_view_from_payload(
3763 &client
->communication
.outbound
.payload
, 0, -1);
3764 const bool has_data
= pv
.buffer
.size
!= 0;
3765 const bool has_fds
= lttng_payload_view_get_fd_handle_count(&pv
);
3767 return has_data
|| has_fds
;
3771 int client_handle_transmission_status(
3772 struct notification_client
*client
,
3773 enum client_transmission_status transmission_status
,
3774 struct notification_thread_state
*state
)
3778 switch (transmission_status
) {
3779 case CLIENT_TRANSMISSION_STATUS_COMPLETE
:
3780 case CLIENT_TRANSMISSION_STATUS_QUEUED
:
3782 int current_poll_events
;
3783 int new_poll_events
;
3785 * We want to be notified whenever there is buffer space
3786 * available to send the rest of the payload if we are
3787 * waiting to send data to the client.
3789 * The state of the outbound queue being sampled here is
3791 * - it is okay to wake-up "for nothing" in case we see
3792 * that data is left, but another thread succeeds in
3793 * flushing it before us when handling the client "out"
3794 * event. We will simply stop monitoring that event the next
3795 * time it wakes us up and we see no data left to be sent,
3796 * - if another thread fails to flush the entire client
3797 * outgoing queue, it will issue a "communication update"
3798 * command and cause the client's (e)poll mask to be
3801 * The situation we seek to avoid would be to disable the
3802 * monitoring of "out" client events indefinitely when there is
3803 * data to be sent, which can't happen because of the
3804 * aforementioned "communication update" mechanism.
3806 pthread_mutex_lock(&client
->lock
);
3807 current_poll_events
= client
->communication
.current_poll_events
;
3808 new_poll_events
= client_has_outbound_data_left(client
) ?
3809 CLIENT_POLL_EVENTS_IN_OUT
:
3810 CLIENT_POLL_EVENTS_IN
;
3811 client
->communication
.current_poll_events
= new_poll_events
;
3812 pthread_mutex_unlock(&client
->lock
);
3814 /* Update the monitored event set only if it changed. */
3815 if (current_poll_events
!= new_poll_events
) {
3816 ret
= lttng_poll_mod(&state
->events
, client
->socket
,
3825 case CLIENT_TRANSMISSION_STATUS_FAIL
:
3826 ret
= notification_thread_client_disconnect(client
, state
);
3831 case CLIENT_TRANSMISSION_STATUS_ERROR
:
3841 /* Client lock must be acquired by caller. */
3843 enum client_transmission_status
client_flush_outgoing_queue(
3844 struct notification_client
*client
)
3847 size_t to_send_count
;
3848 enum client_transmission_status status
;
3849 struct lttng_payload_view pv
= lttng_payload_view_from_payload(
3850 &client
->communication
.outbound
.payload
, 0, -1);
3851 const int fds_to_send_count
=
3852 lttng_payload_view_get_fd_handle_count(&pv
);
3854 ASSERT_LOCKED(client
->lock
);
3856 if (!client
->communication
.active
) {
3857 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3861 if (pv
.buffer
.size
== 0) {
3863 * If both data and fds are equal to zero, we are in an invalid
3866 LTTNG_ASSERT(fds_to_send_count
!= 0);
3871 to_send_count
= pv
.buffer
.size
;
3872 DBG("Flushing client (socket fd = %i) outgoing queue",
3875 ret
= lttcomm_send_unix_sock_non_block(client
->socket
,
3878 if ((ret
>= 0 && ret
< to_send_count
)) {
3879 DBG("Client (socket fd = %i) outgoing queue could not be completely flushed",
3881 to_send_count
-= std::max(ret
, (ssize_t
) 0);
3883 memmove(client
->communication
.outbound
.payload
.buffer
.data
,
3885 pv
.buffer
.size
- to_send_count
,
3887 ret
= lttng_dynamic_buffer_set_size(
3888 &client
->communication
.outbound
.payload
.buffer
,
3894 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3896 } else if (ret
< 0) {
3897 /* Generic error, disable the client's communication. */
3898 ERR("Failed to flush outgoing queue, disconnecting client (socket fd = %i)",
3900 client
->communication
.active
= false;
3901 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3905 * No error and flushed the queue completely.
3907 * The payload buffer size is used later to
3908 * check if there is notifications queued. So albeit that the
3909 * direct caller knows that the transmission is complete, we
3910 * need to set the buffer size to zero.
3912 ret
= lttng_dynamic_buffer_set_size(
3913 &client
->communication
.outbound
.payload
.buffer
, 0);
3920 /* No fds to send, transmission is complete. */
3921 if (fds_to_send_count
== 0) {
3922 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3926 ret
= lttcomm_send_payload_view_fds_unix_sock_non_block(
3927 client
->socket
, &pv
);
3929 /* Generic error, disable the client's communication. */
3930 ERR("Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)",
3932 client
->communication
.active
= false;
3933 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3935 } else if (ret
== 0) {
3936 /* Nothing could be sent. */
3937 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3939 /* Fd passing is an all or nothing kind of thing. */
3940 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3942 * The payload _fd_array count is used later to
3943 * check if there is notifications queued. So although the
3944 * direct caller knows that the transmission is complete, we
3945 * need to clear the _fd_array for the queuing check.
3947 lttng_dynamic_pointer_array_clear(
3948 &client
->communication
.outbound
.payload
3953 if (status
== CLIENT_TRANSMISSION_STATUS_COMPLETE
) {
3954 client
->communication
.outbound
.queued_command_reply
= false;
3955 client
->communication
.outbound
.dropped_notification
= false;
3956 lttng_payload_clear(&client
->communication
.outbound
.payload
);
3961 return CLIENT_TRANSMISSION_STATUS_ERROR
;
3964 /* Client lock must _not_ be held by the caller. */
3966 int client_send_command_reply(struct notification_client
*client
,
3967 struct notification_thread_state
*state
,
3968 enum lttng_notification_channel_status status
)
3971 struct lttng_notification_channel_command_reply reply
= {
3972 .status
= (int8_t) status
,
3974 struct lttng_notification_channel_message msg
;
3975 char buffer
[sizeof(msg
) + sizeof(reply
)];
3976 enum client_transmission_status transmission_status
;
3978 msg
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY
;
3979 msg
.size
= sizeof(reply
);
3982 memcpy(buffer
, &msg
, sizeof(msg
));
3983 memcpy(buffer
+ sizeof(msg
), &reply
, sizeof(reply
));
3984 DBG("Send command reply (%i)", (int) status
);
3986 pthread_mutex_lock(&client
->lock
);
3987 if (client
->communication
.outbound
.queued_command_reply
) {
3988 /* Protocol error. */
3992 /* Enqueue buffer to outgoing queue and flush it. */
3993 ret
= lttng_dynamic_buffer_append(
3994 &client
->communication
.outbound
.payload
.buffer
,
3995 buffer
, sizeof(buffer
));
4000 transmission_status
= client_flush_outgoing_queue(client
);
4002 if (client_has_outbound_data_left(client
)) {
4003 /* Queue could not be emptied. */
4004 client
->communication
.outbound
.queued_command_reply
= true;
4007 pthread_mutex_unlock(&client
->lock
);
4008 ret
= client_handle_transmission_status(
4009 client
, transmission_status
, state
);
4016 pthread_mutex_unlock(&client
->lock
);
4022 int client_handle_message_unknown(struct notification_client
*client
,
4023 struct notification_thread_state
*state
__attribute__((unused
)))
4027 * Receiving message header. The function will be called again
4028 * once the rest of the message as been received and can be
4031 const struct lttng_notification_channel_message
*msg
;
4033 LTTNG_ASSERT(sizeof(*msg
) == client
->communication
.inbound
.payload
.buffer
.size
);
4034 msg
= (const struct lttng_notification_channel_message
*)
4035 client
->communication
.inbound
.payload
.buffer
.data
;
4037 if (msg
->size
== 0 ||
4038 msg
->size
> DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE
) {
4039 ERR("Invalid notification channel message: length = %u",
4045 switch (msg
->type
) {
4046 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
4047 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
4048 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
4052 ERR("Invalid notification channel message: unexpected message type");
4056 client
->communication
.inbound
.bytes_to_receive
= msg
->size
;
4057 client
->communication
.inbound
.fds_to_receive
= msg
->fds
;
4058 client
->communication
.inbound
.msg_type
=
4059 (enum lttng_notification_channel_message_type
) msg
->type
;
4060 ret
= lttng_dynamic_buffer_set_size(
4061 &client
->communication
.inbound
.payload
.buffer
, msg
->size
);
4063 /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */
4070 int client_handle_message_handshake(struct notification_client
*client
,
4071 struct notification_thread_state
*state
)
4074 struct lttng_notification_channel_command_handshake
*handshake_client
;
4075 const struct lttng_notification_channel_command_handshake handshake_reply
= {
4076 .major
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
,
4077 .minor
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR
,
4079 struct lttng_notification_channel_message msg_header
;
4080 enum lttng_notification_channel_status status
=
4081 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
4082 char send_buffer
[sizeof(msg_header
) + sizeof(handshake_reply
)];
4084 msg_header
.type
= LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
;
4085 msg_header
.size
= sizeof(handshake_reply
);
4088 memcpy(send_buffer
, &msg_header
, sizeof(msg_header
));
4089 memcpy(send_buffer
+ sizeof(msg_header
), &handshake_reply
,
4090 sizeof(handshake_reply
));
4093 (struct lttng_notification_channel_command_handshake
*)
4094 client
->communication
.inbound
.payload
.buffer
4096 client
->major
= handshake_client
->major
;
4097 client
->minor
= handshake_client
->minor
;
4098 if (!client
->communication
.inbound
.creds_received
) {
4099 ERR("No credentials received from client");
4104 client
->uid
= LTTNG_SOCK_GET_UID_CRED(
4105 &client
->communication
.inbound
.creds
);
4106 client
->gid
= LTTNG_SOCK_GET_GID_CRED(
4107 &client
->communication
.inbound
.creds
);
4108 client
->is_sessiond
= LTTNG_SOCK_GET_PID_CRED(&client
->communication
.inbound
.creds
) == getpid();
4109 DBG("Received handshake from client: uid = %u, gid = %u, protocol version = %i.%i, client is sessiond = %s",
4110 client
->uid
, client
->gid
, (int) client
->major
,
4111 (int) client
->minor
,
4112 client
->is_sessiond
? "true" : "false");
4114 if (handshake_client
->major
!=
4115 LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
) {
4116 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION
;
4119 pthread_mutex_lock(&client
->lock
);
4120 /* Outgoing queue will be flushed when the command reply is sent. */
4121 ret
= lttng_dynamic_buffer_append(
4122 &client
->communication
.outbound
.payload
.buffer
, send_buffer
,
4123 sizeof(send_buffer
));
4125 ERR("Failed to send protocol version to notification channel client");
4129 client
->validated
= true;
4130 client
->communication
.active
= true;
4131 pthread_mutex_unlock(&client
->lock
);
4133 /* Set reception state to receive the next message header. */
4134 ret
= client_reset_inbound_state(client
);
4136 ERR("Failed to reset client communication's inbound state");
4140 /* Flushes the outgoing queue. */
4141 ret
= client_send_command_reply(client
, state
, status
);
4143 ERR("Failed to send reply to notification channel client");
4149 pthread_mutex_unlock(&client
->lock
);
4155 int client_handle_message_subscription(
4156 struct notification_client
*client
,
4157 enum lttng_notification_channel_message_type msg_type
,
4158 struct notification_thread_state
*state
)
4161 struct lttng_condition
*condition
;
4162 enum lttng_notification_channel_status status
=
4163 LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
4164 struct lttng_payload_view condition_view
=
4165 lttng_payload_view_from_payload(
4166 &client
->communication
.inbound
.payload
,
4168 size_t expected_condition_size
;
4171 * No need to lock client to sample the inbound state as the only
4172 * other thread accessing clients (action executor) only uses the
4175 expected_condition_size
= client
->communication
.inbound
.payload
.buffer
.size
;
4176 ret
= lttng_condition_create_from_payload(&condition_view
, &condition
);
4177 if (ret
!= expected_condition_size
) {
4178 ERR("Malformed condition received from client");
4182 /* Ownership of condition is always transferred. */
4183 if (msg_type
== LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
) {
4184 ret
= notification_thread_client_subscribe(
4185 client
, condition
, state
, &status
);
4187 ret
= notification_thread_client_unsubscribe(
4188 client
, condition
, state
, &status
);
4195 /* Set reception state to receive the next message header. */
4196 ret
= client_reset_inbound_state(client
);
4198 ERR("Failed to reset client communication's inbound state");
4202 ret
= client_send_command_reply(client
, state
, status
);
4204 ERR("Failed to send reply to notification channel client");
4213 int client_dispatch_message(struct notification_client
*client
,
4214 struct notification_thread_state
*state
)
4218 if (client
->communication
.inbound
.msg_type
!=
4219 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
&&
4220 client
->communication
.inbound
.msg_type
!=
4221 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
&&
4222 !client
->validated
) {
4223 WARN("client attempted a command before handshake");
4228 switch (client
->communication
.inbound
.msg_type
) {
4229 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
:
4231 ret
= client_handle_message_unknown(client
, state
);
4234 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
4236 ret
= client_handle_message_handshake(client
, state
);
4239 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
4240 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
4242 ret
= client_handle_message_subscription(client
,
4243 client
->communication
.inbound
.msg_type
, state
);
4253 /* Incoming data from client. */
4254 int handle_notification_thread_client_in(
4255 struct notification_thread_state
*state
, int socket
)
4258 struct notification_client
*client
;
4263 client
= get_client_from_socket(socket
, state
);
4265 /* Internal error, abort. */
4270 if (client
->communication
.inbound
.bytes_to_receive
== 0 &&
4271 client
->communication
.inbound
.fds_to_receive
!= 0) {
4272 /* Only FDs left to receive. */
4276 offset
= client
->communication
.inbound
.payload
.buffer
.size
-
4277 client
->communication
.inbound
.bytes_to_receive
;
4278 if (client
->communication
.inbound
.expect_creds
) {
4279 recv_ret
= lttcomm_recv_creds_unix_sock(socket
,
4280 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4281 client
->communication
.inbound
.bytes_to_receive
,
4282 &client
->communication
.inbound
.creds
);
4284 client
->communication
.inbound
.expect_creds
= false;
4285 client
->communication
.inbound
.creds_received
= true;
4288 recv_ret
= lttcomm_recv_unix_sock_non_block(socket
,
4289 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4290 client
->communication
.inbound
.bytes_to_receive
);
4292 if (recv_ret
>= 0) {
4293 client
->communication
.inbound
.bytes_to_receive
-= recv_ret
;
4295 goto error_disconnect_client
;
4298 if (client
->communication
.inbound
.bytes_to_receive
!= 0) {
4299 /* Message incomplete wait for more data. */
4305 LTTNG_ASSERT(client
->communication
.inbound
.bytes_to_receive
== 0);
4308 if (client
->communication
.inbound
.fds_to_receive
!= 0) {
4309 ret
= lttcomm_recv_payload_fds_unix_sock_non_block(
4311 client
->communication
.inbound
.fds_to_receive
,
4312 &client
->communication
.inbound
.payload
);
4315 * Fds received. non blocking fds passing is all
4318 ssize_t expected_size
;
4320 expected_size
= sizeof(int) *
4321 client
->communication
.inbound
4323 LTTNG_ASSERT(ret
== expected_size
);
4324 client
->communication
.inbound
.fds_to_receive
= 0;
4325 } else if (ret
== 0) {
4326 /* Received nothing. */
4330 goto error_disconnect_client
;
4334 /* At this point the message is complete.*/
4335 LTTNG_ASSERT(client
->communication
.inbound
.bytes_to_receive
== 0 &&
4336 client
->communication
.inbound
.fds_to_receive
== 0);
4337 ret
= client_dispatch_message(client
, state
);
4340 * Only returns an error if this client must be
4343 goto error_disconnect_client
;
4350 error_disconnect_client
:
4351 ret
= notification_thread_client_disconnect(client
, state
);
4355 /* Client ready to receive outgoing data. */
4356 int handle_notification_thread_client_out(
4357 struct notification_thread_state
*state
, int socket
)
4360 struct notification_client
*client
;
4361 enum client_transmission_status transmission_status
;
4364 client
= get_client_from_socket(socket
, state
);
4366 /* Internal error, abort. */
4371 pthread_mutex_lock(&client
->lock
);
4372 if (!client_has_outbound_data_left(client
)) {
4374 * A client "out" event can be received when no payload is left
4375 * to send under some circumstances.
4377 * Many threads can flush a client's outgoing queue and, if they
4378 * had to queue their message (socket was full), will use the
4379 * "communication update" command to signal the (e)poll thread
4380 * to monitor for space being made available in the socket.
4382 * Commands are sent over an internal pipe serviced by the same
4383 * thread as the client sockets.
4385 * When space is made available in the socket, there is a race
4386 * between the (e)poll thread and the other threads that may
4387 * wish to use the client's socket to flush its outgoing queue.
4389 * A non-(e)poll thread may attempt (and succeed) in flushing
4390 * the queue before the (e)poll thread gets a chance to service
4391 * the client's "out" event.
4393 * In this situation, the (e)poll thread processing the client
4394 * out event will see an empty payload: there is nothing to do
4395 * except unsubscribing (e)poll "out" events.
4397 * Note that this thread is the (e)poll thread so it can modify
4398 * the (e)poll mask directly without using a communication
4399 * update command. Other threads that flush the outgoing queue
4400 * will use the "communication update" command to wake up this
4401 * thread and force it to monitor "out" events.
4403 * When other threads succeed in emptying the outgoing queue,
4404 * they don't need to update the (e)poll mask: if the "out"
4405 * event is monitored, it will fire once and the (e)poll
4406 * thread will reach this condition, causing the event to
4407 * stop being monitored.
4409 transmission_status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
4411 transmission_status
= client_flush_outgoing_queue(client
);
4413 pthread_mutex_unlock(&client
->lock
);
4415 ret
= client_handle_transmission_status(
4416 client
, transmission_status
, state
);
4426 bool evaluate_buffer_usage_condition(const struct lttng_condition
*condition
,
4427 const struct channel_state_sample
*sample
,
4428 uint64_t buffer_capacity
)
4430 bool result
= false;
4432 enum lttng_condition_type condition_type
;
4433 const struct lttng_condition_buffer_usage
*use_condition
= lttng::utils::container_of(
4434 condition
, <tng_condition_buffer_usage::parent
);
4436 if (use_condition
->threshold_bytes
.set
) {
4437 threshold
= use_condition
->threshold_bytes
.value
;
4440 * Threshold was expressed as a ratio.
4442 * TODO the threshold (in bytes) of conditions expressed
4443 * as a ratio of total buffer size could be cached to
4444 * forego this double-multiplication or it could be performed
4445 * as fixed-point math.
4447 * Note that caching should accommodates the case where the
4448 * condition applies to multiple channels (i.e. don't assume
4449 * that all channels matching my_chann* have the same size...)
4451 threshold
= (uint64_t) (use_condition
->threshold_ratio
.value
*
4452 (double) buffer_capacity
);
4455 condition_type
= lttng_condition_get_type(condition
);
4456 if (condition_type
== LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
) {
4457 DBG("Low buffer usage condition being evaluated: threshold = %" PRIu64
", highest usage = %" PRIu64
,
4458 threshold
, sample
->highest_usage
);
4461 * The low condition should only be triggered once _all_ of the
4462 * streams in a channel have gone below the "low" threshold.
4464 if (sample
->highest_usage
<= threshold
) {
4468 DBG("High buffer usage condition being evaluated: threshold = %" PRIu64
", highest usage = %" PRIu64
,
4469 threshold
, sample
->highest_usage
);
4472 * For high buffer usage scenarios, we want to trigger whenever
4473 * _any_ of the streams has reached the "high" threshold.
4475 if (sample
->highest_usage
>= threshold
) {
4484 int evaluate_buffer_condition(const struct lttng_condition
*condition
,
4485 struct lttng_evaluation
**evaluation
,
4486 const struct notification_thread_state
*state
__attribute__((unused
)),
4487 const struct channel_state_sample
*previous_sample
,
4488 const struct channel_state_sample
*latest_sample
,
4489 struct channel_info
*channel_info
)
4492 enum lttng_condition_type condition_type
;
4493 const bool previous_sample_available
= !!previous_sample
;
4494 bool previous_sample_result
= false;
4495 bool latest_sample_result
;
4497 condition_type
= lttng_condition_get_type(condition
);
4499 switch (condition_type
) {
4500 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4501 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4502 if (caa_likely(previous_sample_available
)) {
4503 previous_sample_result
=
4504 evaluate_buffer_usage_condition(condition
,
4505 previous_sample
, channel_info
->capacity
);
4507 latest_sample_result
= evaluate_buffer_usage_condition(
4508 condition
, latest_sample
,
4509 channel_info
->capacity
);
4512 /* Unknown condition type; internal error. */
4516 if (!latest_sample_result
||
4517 (previous_sample_result
== latest_sample_result
)) {
4519 * Only trigger on a condition evaluation transition.
4521 * NOTE: This edge-triggered logic may not be appropriate for
4522 * future condition types.
4527 if (!evaluation
|| !latest_sample_result
) {
4531 switch (condition_type
) {
4532 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4533 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4534 *evaluation
= lttng_evaluation_buffer_usage_create(
4536 latest_sample
->highest_usage
,
4537 channel_info
->capacity
);
4552 int client_notification_overflow(struct notification_client
*client
)
4555 struct lttng_notification_channel_message msg
;
4557 msg
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED
;
4561 ASSERT_LOCKED(client
->lock
);
4563 DBG("Dropping notification addressed to client (socket fd = %i)",
4565 if (client
->communication
.outbound
.dropped_notification
) {
4567 * The client already has a "notification dropped" message
4568 * in its outgoing queue. Nothing to do since all
4569 * of those messages are coalesced.
4574 client
->communication
.outbound
.dropped_notification
= true;
4575 ret
= lttng_dynamic_buffer_append(
4576 &client
->communication
.outbound
.payload
.buffer
, &msg
,
4579 PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue",
4586 static int client_handle_transmission_status_wrapper(
4587 struct notification_client
*client
,
4588 enum client_transmission_status status
,
4591 return client_handle_transmission_status(client
, status
,
4592 (struct notification_thread_state
*) user_data
);
4596 int send_evaluation_to_clients(const struct lttng_trigger
*trigger
,
4597 const struct lttng_evaluation
*evaluation
,
4598 struct notification_client_list
* client_list
,
4599 struct notification_thread_state
*state
,
4600 uid_t object_uid
, gid_t object_gid
)
4602 const struct lttng_credentials creds
= {
4603 .uid
= LTTNG_OPTIONAL_INIT_VALUE(object_uid
),
4604 .gid
= LTTNG_OPTIONAL_INIT_VALUE(object_gid
),
4607 return notification_client_list_send_evaluation(client_list
,
4608 trigger
, evaluation
,
4610 client_handle_transmission_status_wrapper
, state
);
4614 * Permission checks relative to notification channel clients are performed
4615 * here. Notice how object, client, and trigger credentials are involved in
4618 * The `object` credentials are the credentials associated with the "subject"
4619 * of a condition. For instance, a `rotation completed` condition applies
4620 * to a session. When that condition is met, it will produce an evaluation
4621 * against a session. Hence, in this case, the `object` credentials are the
4622 * credentials of the "subject" session.
4624 * The `trigger` credentials are the credentials of the user that registered the
4627 * The `client` credentials are the credentials of the user that created a given
4628 * notification channel.
4630 * In terms of visibility, it is expected that non-privilieged users can only
4631 * register triggers against "their" objects (their own sessions and
4632 * applications they are allowed to interact with). They can then open a
4633 * notification channel and subscribe to notifications associated with those
4636 * As for privilieged users, they can register triggers against the objects of
4637 * other users. They can then subscribe to the notifications associated to their
4638 * triggers. Privilieged users _can't_ subscribe to the notifications of
4639 * triggers owned by other users; they must create their own triggers.
4641 * This is more a concern of usability than security. It would be difficult for
4642 * a root user reliably subscribe to a specific set of conditions without
4643 * interference from external users (those could, for instance, unregister
4646 int notification_client_list_send_evaluation(
4647 struct notification_client_list
*client_list
,
4648 const struct lttng_trigger
*trigger
,
4649 const struct lttng_evaluation
*evaluation
,
4650 const struct lttng_credentials
*source_object_creds
,
4651 report_client_transmission_result_cb client_report
,
4655 struct lttng_payload msg_payload
;
4656 struct notification_client_list_element
*client_list_element
, *tmp
;
4657 const struct lttng_notification notification
= {
4658 .trigger
= (struct lttng_trigger
*) trigger
,
4659 .evaluation
= (struct lttng_evaluation
*) evaluation
,
4661 struct lttng_notification_channel_message msg_header
;
4662 const struct lttng_credentials
*trigger_creds
=
4663 lttng_trigger_get_credentials(trigger
);
4665 lttng_payload_init(&msg_payload
);
4667 msg_header
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION
;
4668 msg_header
.size
= 0;
4671 ret
= lttng_dynamic_buffer_append(&msg_payload
.buffer
, &msg_header
,
4672 sizeof(msg_header
));
4677 ret
= lttng_notification_serialize(¬ification
, &msg_payload
);
4679 ERR("Failed to serialize notification");
4684 /* Update payload size. */
4685 ((struct lttng_notification_channel_message
*) msg_payload
.buffer
.data
)
4686 ->size
= (uint32_t)(
4687 msg_payload
.buffer
.size
- sizeof(msg_header
));
4689 /* Update the payload number of fds. */
4691 const struct lttng_payload_view pv
= lttng_payload_view_from_payload(
4692 &msg_payload
, 0, -1);
4694 ((struct lttng_notification_channel_message
*)
4695 msg_payload
.buffer
.data
)->fds
= (uint32_t)
4696 lttng_payload_view_get_fd_handle_count(&pv
);
4699 pthread_mutex_lock(&client_list
->lock
);
4700 cds_list_for_each_entry_safe(client_list_element
, tmp
,
4701 &client_list
->clients_list
, node
) {
4702 enum client_transmission_status transmission_status
;
4703 struct notification_client
*client
=
4704 client_list_element
->client
;
4707 pthread_mutex_lock(&client
->lock
);
4708 if (!client
->communication
.active
) {
4710 * Skip inactive client (protocol error or
4713 DBG("Skipping client at it is marked as inactive");
4717 if (lttng_trigger_is_hidden(trigger
) && !client
->is_sessiond
) {
4719 * Notifications resulting from an hidden trigger are
4720 * only sent to the session daemon.
4722 DBG("Skipping client as the trigger is hidden and the client is not the session daemon");
4726 if (source_object_creds
) {
4727 if (client
->uid
!= lttng_credentials_get_uid(source_object_creds
) &&
4728 client
->gid
!= lttng_credentials_get_gid(source_object_creds
) &&
4731 * Client is not allowed to monitor this
4734 DBG("Skipping client at it does not have the object permission to receive notification for this trigger");
4739 if (client
->uid
!= lttng_credentials_get_uid(trigger_creds
)) {
4740 DBG("Skipping client at it does not have the permission to receive notification for this trigger");
4744 DBG("Sending notification to client (fd = %i, %zu bytes)",
4745 client
->socket
, msg_payload
.buffer
.size
);
4747 if (client_has_outbound_data_left(client
)) {
4749 * Outgoing data is already buffered for this client;
4750 * drop the notification and enqueue a "dropped
4751 * notification" message if this is the first dropped
4752 * notification since the socket spilled-over to the
4755 ret
= client_notification_overflow(client
);
4762 ret
= lttng_payload_copy(&msg_payload
, &client
->communication
.outbound
.payload
);
4768 transmission_status
= client_flush_outgoing_queue(client
);
4769 pthread_mutex_unlock(&client
->lock
);
4770 ret
= client_report(client
, transmission_status
, user_data
);
4773 goto end_unlock_list
;
4779 pthread_mutex_unlock(&client
->lock
);
4782 goto end_unlock_list
;
4788 pthread_mutex_unlock(&client_list
->lock
);
4790 lttng_payload_reset(&msg_payload
);
4795 struct lttng_event_notifier_notification
*recv_one_event_notifier_notification(
4796 int notification_pipe_read_fd
, enum lttng_domain_type domain
)
4800 struct lttng_event_notifier_notification
*notification
= NULL
;
4801 char *capture_buffer
= NULL
;
4802 size_t capture_buffer_size
;
4803 void *reception_buffer
;
4804 size_t reception_size
;
4806 struct lttng_ust_abi_event_notifier_notification ust_notification
;
4807 struct lttng_kernel_abi_event_notifier_notification kernel_notification
;
4809 /* Init lttng_event_notifier_notification */
4811 case LTTNG_DOMAIN_UST
:
4812 reception_buffer
= (void *) &ust_notification
;
4813 reception_size
= sizeof(ust_notification
);
4815 case LTTNG_DOMAIN_KERNEL
:
4816 reception_buffer
= (void *) &kernel_notification
;
4817 reception_size
= sizeof(kernel_notification
);
4824 * The monitoring pipe only holds messages smaller than PIPE_BUF,
4825 * ensuring that read/write of tracer notifications are atomic.
4827 ret
= lttng_read(notification_pipe_read_fd
, reception_buffer
,
4829 if (ret
!= reception_size
) {
4830 PERROR("Failed to read from event source notification pipe: fd = %d, size to read = %zu, ret = %d",
4831 notification_pipe_read_fd
, reception_size
, ret
);
4837 case LTTNG_DOMAIN_UST
:
4838 token
= ust_notification
.token
;
4839 capture_buffer_size
= ust_notification
.capture_buf_size
;
4841 case LTTNG_DOMAIN_KERNEL
:
4842 token
= kernel_notification
.token
;
4843 capture_buffer_size
= kernel_notification
.capture_buf_size
;
4849 if (capture_buffer_size
== 0) {
4850 capture_buffer
= NULL
;
4854 if (capture_buffer_size
> MAX_CAPTURE_SIZE
) {
4855 ERR("Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes",
4856 capture_buffer_size
, MAX_CAPTURE_SIZE
);
4860 capture_buffer
= calloc
<char>(capture_buffer_size
);
4861 if (!capture_buffer
) {
4862 ERR("Failed to allocate capture buffer");
4866 /* Fetch additional payload (capture). */
4867 ret
= lttng_read(notification_pipe_read_fd
, capture_buffer
, capture_buffer_size
);
4868 if (ret
!= capture_buffer_size
) {
4869 ERR("Failed to read from event source pipe (fd = %i)",
4870 notification_pipe_read_fd
);
4875 notification
= lttng_event_notifier_notification_create(token
, domain
,
4876 capture_buffer
, capture_buffer_size
);
4877 if (notification
== NULL
) {
4882 * Ownership transfered to the lttng_event_notifier_notification object.
4884 capture_buffer
= NULL
;
4887 free(capture_buffer
);
4888 return notification
;
4892 int dispatch_one_event_notifier_notification(struct notification_thread_state
*state
,
4893 struct lttng_event_notifier_notification
*notification
)
4895 struct cds_lfht_node
*node
;
4896 struct cds_lfht_iter iter
;
4897 struct notification_trigger_tokens_ht_element
*element
;
4898 struct lttng_evaluation
*evaluation
= NULL
;
4899 enum action_executor_status executor_status
;
4900 struct notification_client_list
*client_list
= NULL
;
4902 unsigned int capture_count
= 0;
4904 /* Find triggers associated with this token. */
4906 cds_lfht_lookup(state
->trigger_tokens_ht
,
4907 hash_key_u64(¬ification
->tracer_token
, lttng_ht_seed
),
4908 match_trigger_token
, ¬ification
->tracer_token
, &iter
);
4909 node
= cds_lfht_iter_get_node(&iter
);
4910 if (caa_unlikely(!node
)) {
4912 * This is not an error, slow consumption of the tracer
4913 * notifications can lead to situations where a trigger is
4914 * removed but we still get tracer notifications matching a
4915 * trigger that no longer exists.
4921 element
= caa_container_of(node
,
4922 struct notification_trigger_tokens_ht_element
,
4925 if (lttng_condition_event_rule_matches_get_capture_descriptor_count(
4926 lttng_trigger_get_const_condition(element
->trigger
),
4927 &capture_count
) != LTTNG_CONDITION_STATUS_OK
) {
4928 ERR("Failed to get capture count");
4933 if (!notification
->capture_buffer
&& capture_count
!= 0) {
4934 ERR("Expected capture but capture buffer is null");
4939 evaluation
= lttng_evaluation_event_rule_matches_create(
4940 lttng::utils::container_of(lttng_trigger_get_const_condition(
4942 <tng_condition_event_rule_matches::parent
),
4943 notification
->capture_buffer
,
4944 notification
->capture_buf_size
, false);
4946 if (evaluation
== NULL
) {
4947 ERR("Failed to create event rule matches evaluation while creating and enqueuing action executor job");
4952 client_list
= get_client_list_from_condition(state
,
4953 lttng_trigger_get_const_condition(element
->trigger
));
4954 executor_status
= action_executor_enqueue_trigger(state
->executor
,
4955 element
->trigger
, evaluation
, NULL
, client_list
);
4956 switch (executor_status
) {
4957 case ACTION_EXECUTOR_STATUS_OK
:
4960 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
4962 struct notification_client_list_element
*client_list_element
,
4966 * Not a fatal error; this is expected and simply means the
4967 * executor has too much work queued already.
4971 /* No clients subscribed to notifications for this trigger. */
4976 /* Warn clients that a notification (or more) was dropped. */
4977 pthread_mutex_lock(&client_list
->lock
);
4978 cds_list_for_each_entry_safe(client_list_element
, tmp
,
4979 &client_list
->clients_list
, node
) {
4980 enum client_transmission_status transmission_status
;
4981 struct notification_client
*client
=
4982 client_list_element
->client
;
4984 pthread_mutex_lock(&client
->lock
);
4985 ret
= client_notification_overflow(client
);
4991 transmission_status
=
4992 client_flush_outgoing_queue(client
);
4993 ret
= client_handle_transmission_status(
4994 client
, transmission_status
, state
);
5000 pthread_mutex_unlock(&client
->lock
);
5006 pthread_mutex_unlock(&client_list
->lock
);
5009 case ACTION_EXECUTOR_STATUS_INVALID
:
5010 case ACTION_EXECUTOR_STATUS_ERROR
:
5011 /* Fatal error, shut down everything. */
5012 ERR("Fatal error encoutered while enqueuing action to the action executor");
5016 /* Unhandled error. */
5021 notification_client_list_put(client_list
);
5028 int handle_one_event_notifier_notification(
5029 struct notification_thread_state
*state
,
5030 int pipe
, enum lttng_domain_type domain
)
5033 struct lttng_event_notifier_notification
*notification
= NULL
;
5035 notification
= recv_one_event_notifier_notification(pipe
, domain
);
5036 if (notification
== NULL
) {
5037 /* Reception failed, don't consider it fatal. */
5038 ERR("Error receiving an event notifier notification from tracer: fd = %i, domain = %s",
5039 pipe
, lttng_domain_type_str(domain
));
5043 ret
= dispatch_one_event_notifier_notification(state
, notification
);
5045 ERR("Error dispatching an event notifier notification from tracer: fd = %i, domain = %s",
5046 pipe
, lttng_domain_type_str(domain
));
5051 lttng_event_notifier_notification_destroy(notification
);
5055 int handle_notification_thread_event_notification(struct notification_thread_state
*state
,
5056 int pipe
, enum lttng_domain_type domain
)
5058 return handle_one_event_notifier_notification(state
, pipe
, domain
);
5061 int handle_notification_thread_channel_sample(
5062 struct notification_thread_state
*state
, int pipe
,
5063 enum lttng_domain_type domain
)
5066 struct lttcomm_consumer_channel_monitor_msg sample_msg
;
5067 struct channel_info
*channel_info
= NULL
;
5068 struct cds_lfht_node
*node
;
5069 struct cds_lfht_iter iter
;
5070 struct lttng_channel_trigger_list
*channel_trigger_list
;
5071 struct lttng_session_trigger_list
*session_trigger_list
;
5072 struct lttng_trigger_list_element
*trigger_list_element
;
5073 bool previous_sample_available
= false;
5074 struct channel_state_sample channel_previous_sample
, channel_new_sample
;
5075 struct session_state_sample session_new_sample
;
5076 struct lttng_credentials channel_creds
= {};
5077 struct lttng_credentials session_creds
= {};
5078 struct session_info
*session
;
5081 * The monitoring pipe only holds messages smaller than PIPE_BUF,
5082 * ensuring that read/write of sampling messages are atomic.
5084 ret
= lttng_read(pipe
, &sample_msg
, sizeof(sample_msg
));
5085 if (ret
!= sizeof(sample_msg
)) {
5086 ERR("Failed to read from monitoring pipe (fd = %i)",
5093 channel_new_sample
.key
.key
= sample_msg
.key
;
5094 channel_new_sample
.key
.domain
= domain
;
5095 channel_new_sample
.highest_usage
= sample_msg
.highest
;
5096 channel_new_sample
.lowest_usage
= sample_msg
.lowest
;
5100 session
= get_session_info_by_id(state
, sample_msg
.session_id
);
5102 DBG("Received a sample for an unknown session from consumerd: session id = %" PRIu64
,
5103 sample_msg
.session_id
);
5107 session_new_sample
= session
->last_state_sample
;
5108 session_new_sample
.consumed_data_size
+= sample_msg
.consumed_since_last_sample
;
5110 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session
->uid
),
5111 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session
->gid
),
5114 session_trigger_list
= get_session_trigger_list(state
, session
->name
);
5115 LTTNG_ASSERT(session_trigger_list
);
5116 cds_list_for_each_entry(trigger_list_element
, &session_trigger_list
->list
,
5118 const struct lttng_condition
*condition
;
5119 struct lttng_trigger
*trigger
;
5120 struct notification_client_list
*client_list
= NULL
;
5121 struct lttng_evaluation
*evaluation
= NULL
;
5122 enum action_executor_status executor_status
;
5125 trigger
= trigger_list_element
->trigger
;
5126 condition
= lttng_trigger_get_const_condition(trigger
);
5127 LTTNG_ASSERT(condition
);
5129 ret
= evaluate_session_condition(
5130 condition
, session
, &session_new_sample
, &evaluation
);
5131 if (caa_unlikely(ret
)) {
5135 if (caa_likely(!evaluation
)) {
5140 * Ownership of `evaluation` transferred to the action executor
5141 * no matter the result. The callee acquires a reference to the
5142 * client list: we can release our own.
5144 client_list
= get_client_list_from_condition(state
, condition
);
5145 executor_status
= action_executor_enqueue_trigger(
5146 state
->executor
, trigger
, evaluation
,
5147 &session_creds
, client_list
);
5148 notification_client_list_put(client_list
);
5150 switch (executor_status
) {
5151 case ACTION_EXECUTOR_STATUS_OK
:
5153 case ACTION_EXECUTOR_STATUS_ERROR
:
5154 case ACTION_EXECUTOR_STATUS_INVALID
:
5156 * TODO Add trigger identification (name/id) when
5157 * it is added to the API.
5159 ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
5162 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
5164 * TODO Add trigger identification (name/id) when
5165 * it is added to the API.
5167 * Not a fatal error.
5169 WARN("No space left when enqueuing action associated with buffer-condition trigger");
5177 /* Retrieve the channel's informations */
5178 cds_lfht_lookup(state
->channels_ht
,
5179 hash_channel_key(&channel_new_sample
.key
),
5181 &channel_new_sample
.key
,
5183 node
= cds_lfht_iter_get_node(&iter
);
5184 if (caa_unlikely(!node
)) {
5186 * Not an error since the consumer can push a sample to the pipe
5187 * and the rest of the session daemon could notify us of the
5188 * channel's destruction before we get a chance to process that
5191 DBG("Received a sample for an unknown channel from consumerd, key = %" PRIu64
" in %s domain",
5192 channel_new_sample
.key
.key
,
5193 lttng_domain_type_str(domain
));
5197 channel_info
= caa_container_of(node
, struct channel_info
,
5199 DBG("Handling channel sample for channel %s (key = %" PRIu64
") in session %s (highest usage = %" PRIu64
", lowest usage = %" PRIu64
", consumed since last sample = %" PRIu64
")",
5201 channel_new_sample
.key
.key
,
5202 channel_info
->session_info
->name
,
5203 channel_new_sample
.highest_usage
,
5204 channel_new_sample
.lowest_usage
,
5205 sample_msg
.consumed_since_last_sample
);
5207 /* Retrieve the channel's last sample, if it exists, and update it. */
5208 cds_lfht_lookup(state
->channel_state_ht
,
5209 hash_channel_key(&channel_new_sample
.key
),
5210 match_channel_state_sample
,
5211 &channel_new_sample
.key
,
5213 node
= cds_lfht_iter_get_node(&iter
);
5214 if (caa_likely(node
)) {
5215 struct channel_state_sample
*stored_sample
;
5217 /* Update the sample stored. */
5218 stored_sample
= caa_container_of(node
,
5219 struct channel_state_sample
,
5220 channel_state_ht_node
);
5222 memcpy(&channel_previous_sample
, stored_sample
,
5223 sizeof(channel_previous_sample
));
5224 stored_sample
->highest_usage
= channel_new_sample
.highest_usage
;
5225 stored_sample
->lowest_usage
= channel_new_sample
.lowest_usage
;
5226 previous_sample_available
= true;
5229 * This is the channel's first sample, allocate space for and
5230 * store the new sample.
5232 struct channel_state_sample
*stored_sample
;
5234 stored_sample
= zmalloc
<channel_state_sample
>();
5235 if (!stored_sample
) {
5240 memcpy(stored_sample
, &channel_new_sample
, sizeof(*stored_sample
));
5241 cds_lfht_node_init(&stored_sample
->channel_state_ht_node
);
5242 cds_lfht_add(state
->channel_state_ht
,
5243 hash_channel_key(&stored_sample
->key
),
5244 &stored_sample
->channel_state_ht_node
);
5247 /* Find triggers associated with this channel. */
5248 cds_lfht_lookup(state
->channel_triggers_ht
,
5249 hash_channel_key(&channel_new_sample
.key
),
5250 match_channel_trigger_list
,
5251 &channel_new_sample
.key
,
5253 node
= cds_lfht_iter_get_node(&iter
);
5256 channel_creds
= (typeof(channel_creds
)) {
5257 .uid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->uid
),
5258 .gid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->gid
),
5261 channel_trigger_list
= caa_container_of(node
, struct lttng_channel_trigger_list
,
5262 channel_triggers_ht_node
);
5263 cds_list_for_each_entry(trigger_list_element
, &channel_trigger_list
->list
,
5265 const struct lttng_condition
*condition
;
5266 struct lttng_trigger
*trigger
;
5267 struct notification_client_list
*client_list
= NULL
;
5268 struct lttng_evaluation
*evaluation
= NULL
;
5269 enum action_executor_status executor_status
;
5272 trigger
= trigger_list_element
->trigger
;
5273 condition
= lttng_trigger_get_const_condition(trigger
);
5274 LTTNG_ASSERT(condition
);
5276 ret
= evaluate_buffer_condition(condition
, &evaluation
, state
,
5277 previous_sample_available
? &channel_previous_sample
: NULL
,
5278 &channel_new_sample
,
5280 if (caa_unlikely(ret
)) {
5284 if (caa_likely(!evaluation
)) {
5289 * Ownership of `evaluation` transferred to the action executor
5290 * no matter the result. The callee acquires a reference to the
5291 * client list: we can release our own.
5293 client_list
= get_client_list_from_condition(state
, condition
);
5294 executor_status
= action_executor_enqueue_trigger(
5295 state
->executor
, trigger
, evaluation
,
5296 &channel_creds
, client_list
);
5297 notification_client_list_put(client_list
);
5299 switch (executor_status
) {
5300 case ACTION_EXECUTOR_STATUS_OK
:
5302 case ACTION_EXECUTOR_STATUS_ERROR
:
5303 case ACTION_EXECUTOR_STATUS_INVALID
:
5305 * TODO Add trigger identification (name/id) when
5306 * it is added to the API.
5308 ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
5311 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
5313 * TODO Add trigger identification (name/id) when
5314 * it is added to the API.
5316 * Not a fatal error.
5318 WARN("No space left when enqueuing action associated with buffer-condition trigger");
5327 session
->last_state_sample
= session_new_sample
;
5329 session_info_put(session
);