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"
11 #include "condition-internal.hpp"
12 #include "event-notifier-error-accounting.hpp"
14 #include "lttng-sessiond.hpp"
15 #include "notification-thread-commands.hpp"
16 #include "notification-thread-events.hpp"
17 #include "notification-thread.hpp"
19 #include <common/defaults.hpp>
20 #include <common/dynamic-buffer.hpp>
21 #include <common/error.hpp>
22 #include <common/futex.hpp>
23 #include <common/hashtable/utils.hpp>
24 #include <common/macros.hpp>
25 #include <common/pthread-lock.hpp>
26 #include <common/sessiond-comm/sessiond-comm.hpp>
27 #include <common/unix.hpp>
28 #include <common/urcu.hpp>
30 #include <lttng/action/action-internal.hpp>
31 #include <lttng/action/list-internal.hpp>
32 #include <lttng/condition/buffer-usage-internal.hpp>
33 #include <lttng/condition/condition-internal.hpp>
34 #include <lttng/condition/condition.h>
35 #include <lttng/condition/event-rule-matches-internal.hpp>
36 #include <lttng/condition/session-consumed-size-internal.hpp>
37 #include <lttng/condition/session-rotation-internal.hpp>
38 #include <lttng/domain-internal.hpp>
39 #include <lttng/event-rule/event-rule-internal.hpp>
40 #include <lttng/location-internal.hpp>
41 #include <lttng/notification/channel-internal.hpp>
42 #include <lttng/notification/notification-internal.hpp>
43 #include <lttng/trigger/trigger-internal.hpp>
50 #include <urcu/rculfhash.h>
52 #define CLIENT_POLL_EVENTS_IN (LPOLLIN | LPOLLRDHUP)
53 #define CLIENT_POLL_EVENTS_IN_OUT (CLIENT_POLL_EVENTS_IN | LPOLLOUT)
55 /* The tracers currently limit the capture size to PIPE_BUF (4kb on linux). */
56 #define MAX_CAPTURE_SIZE (PIPE_BUF)
58 enum lttng_object_type
{
59 LTTNG_OBJECT_TYPE_UNKNOWN
,
60 LTTNG_OBJECT_TYPE_NONE
,
61 LTTNG_OBJECT_TYPE_CHANNEL
,
62 LTTNG_OBJECT_TYPE_SESSION
,
65 struct lttng_channel_trigger_list
{
66 struct channel_key channel_key
;
67 /* List of struct lttng_trigger_list_element. */
68 struct cds_list_head list
;
69 /* Node in the channel_triggers_ht */
70 struct cds_lfht_node channel_triggers_ht_node
;
71 /* call_rcu delayed reclaim. */
72 struct rcu_head rcu_node
;
76 * List of triggers applying to a given session.
79 * - lttng_session_trigger_list_create()
80 * - lttng_session_trigger_list_build()
81 * - lttng_session_trigger_list_destroy()
82 * - lttng_session_trigger_list_add()
84 struct lttng_session_trigger_list
{
86 /* List of struct lttng_trigger_list_element. */
87 struct cds_list_head list
;
88 /* Node in the session_triggers_ht */
89 struct cds_lfht_node session_triggers_ht_node
;
91 * Weak reference to the notification system's session triggers
94 * The session trigger list structure structure is owned by
95 * the session's session_info.
97 * The session_info is kept alive the the channel_infos holding a
98 * reference to it (reference counting). When those channels are
99 * destroyed (at runtime or on teardown), the reference they hold
100 * to the session_info are released. On destruction of session_info,
101 * session_info_destroy() will remove the list of triggers applying
102 * to this session from the notification system's state.
104 * This implies that the session_triggers_ht must be destroyed
105 * after the channels.
107 struct cds_lfht
*session_triggers_ht
;
108 /* Used for delayed RCU reclaim. */
109 struct rcu_head rcu_node
;
113 struct lttng_trigger_list_element
{
114 /* No ownership of the trigger object is assumed. */
115 struct lttng_trigger
*trigger
;
116 struct cds_list_head node
;
119 struct lttng_trigger_ht_element
{
120 struct lttng_trigger
*trigger
;
121 struct cds_lfht_node node
;
122 struct cds_lfht_node node_by_name_uid
;
123 struct cds_list_head client_list_trigger_node
;
124 /* call_rcu delayed reclaim. */
125 struct rcu_head rcu_node
;
128 struct lttng_condition_list_element
{
129 struct lttng_condition
*condition
;
130 struct cds_list_head node
;
133 struct channel_state_sample
{
134 struct channel_key key
;
135 struct cds_lfht_node channel_state_ht_node
;
136 uint64_t highest_usage
;
137 uint64_t lowest_usage
;
138 /* call_rcu delayed reclaim. */
139 struct rcu_head rcu_node
;
143 static unsigned long hash_channel_key(struct channel_key
*key
);
144 static int evaluate_buffer_condition(const struct lttng_condition
*condition
,
145 struct lttng_evaluation
**evaluation
,
146 const struct notification_thread_state
*state
,
147 const struct channel_state_sample
*previous_sample
,
148 const struct channel_state_sample
*latest_sample
,
149 struct channel_info
*channel_info
);
150 static 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
,
157 /* session_info API */
158 static void session_info_destroy(void *_data
);
159 static void session_info_get(struct session_info
*session_info
);
160 static void session_info_put(struct session_info
*session_info
);
161 static struct session_info
*session_info_create(uint64_t id
,
165 struct lttng_session_trigger_list
*trigger_list
,
166 struct cds_lfht
*sessions_ht
);
167 static void session_info_add_channel(struct session_info
*session_info
,
168 struct channel_info
*channel_info
);
169 static void session_info_remove_channel(struct session_info
*session_info
,
170 struct channel_info
*channel_info
);
172 /* lttng_session_trigger_list API */
173 static struct lttng_session_trigger_list
*
174 lttng_session_trigger_list_create(const char *session_name
, struct cds_lfht
*session_triggers_ht
);
175 static struct lttng_session_trigger_list
*
176 lttng_session_trigger_list_build(const struct notification_thread_state
*state
,
177 const char *session_name
);
178 static void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list
*list
);
179 static int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
180 struct lttng_trigger
*trigger
);
182 static int client_handle_transmission_status(struct notification_client
*client
,
183 enum client_transmission_status transmission_status
,
184 struct notification_thread_state
*state
);
186 static int handle_one_event_notifier_notification(struct notification_thread_state
*state
,
188 enum lttng_domain_type domain
);
190 static void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
);
192 static int match_client_socket(struct cds_lfht_node
*node
, const void *key
)
194 /* This double-cast is intended to supress pointer-to-cast warning. */
195 const int socket
= (int) (intptr_t) key
;
196 const struct notification_client
*client
=
197 caa_container_of(node
, struct notification_client
, client_socket_ht_node
);
199 return client
->socket
== socket
;
202 static int match_client_id(struct cds_lfht_node
*node
, const void *key
)
204 /* This double-cast is intended to supress pointer-to-cast warning. */
205 const notification_client_id id
= *((notification_client_id
*) key
);
206 const struct notification_client
*client
=
207 lttng::utils::container_of(node
, ¬ification_client::client_id_ht_node
);
209 return client
->id
== id
;
212 static int match_channel_trigger_list(struct cds_lfht_node
*node
, const void *key
)
214 struct channel_key
*channel_key
= (struct channel_key
*) key
;
215 struct lttng_channel_trigger_list
*trigger_list
;
218 caa_container_of(node
, struct lttng_channel_trigger_list
, channel_triggers_ht_node
);
220 return !!((channel_key
->key
== trigger_list
->channel_key
.key
) &&
221 (channel_key
->domain
== trigger_list
->channel_key
.domain
));
224 static int match_session_trigger_list(struct cds_lfht_node
*node
, const void *key
)
226 const char *session_name
= (const char *) key
;
227 struct lttng_session_trigger_list
*trigger_list
;
230 caa_container_of(node
, struct lttng_session_trigger_list
, session_triggers_ht_node
);
232 return !!(strcmp(trigger_list
->session_name
, session_name
) == 0);
235 static int match_channel_state_sample(struct cds_lfht_node
*node
, const void *key
)
237 struct channel_key
*channel_key
= (struct channel_key
*) key
;
238 struct channel_state_sample
*sample
;
240 sample
= caa_container_of(node
, struct channel_state_sample
, channel_state_ht_node
);
242 return !!((channel_key
->key
== sample
->key
.key
) &&
243 (channel_key
->domain
== sample
->key
.domain
));
246 static int match_channel_info(struct cds_lfht_node
*node
, const void *key
)
248 struct channel_key
*channel_key
= (struct channel_key
*) key
;
249 struct channel_info
*channel_info
;
251 channel_info
= caa_container_of(node
, struct channel_info
, channels_ht_node
);
253 return !!((channel_key
->key
== channel_info
->key
.key
) &&
254 (channel_key
->domain
== channel_info
->key
.domain
));
257 static int match_trigger(struct cds_lfht_node
*node
, const void *key
)
259 struct lttng_trigger
*trigger_key
= (struct lttng_trigger
*) key
;
260 struct lttng_trigger_ht_element
*trigger_ht_element
;
262 trigger_ht_element
= caa_container_of(node
, struct lttng_trigger_ht_element
, node
);
264 return !!lttng_trigger_is_equal(trigger_key
, trigger_ht_element
->trigger
);
267 static int match_trigger_token(struct cds_lfht_node
*node
, const void *key
)
269 const uint64_t *_key
= (uint64_t *) key
;
270 struct notification_trigger_tokens_ht_element
*element
;
272 element
= caa_container_of(node
, struct notification_trigger_tokens_ht_element
, node
);
273 return *_key
== element
->token
;
276 static int match_client_list_condition(struct cds_lfht_node
*node
, const void *key
)
278 struct lttng_condition
*condition_key
= (struct lttng_condition
*) key
;
279 struct notification_client_list
*client_list
;
280 const struct lttng_condition
*condition
;
282 LTTNG_ASSERT(condition_key
);
284 client_list
= caa_container_of(
285 node
, struct notification_client_list
, notification_trigger_clients_ht_node
);
286 condition
= client_list
->condition
;
288 return !!lttng_condition_is_equal(condition_key
, condition
);
291 static int match_session_info(struct cds_lfht_node
*node
, const void *key
)
293 const auto session_id
= *((uint64_t *) key
);
294 const auto *session_info
=
295 lttng::utils::container_of(node
, &session_info::sessions_ht_node
);
297 return session_id
== session_info
->id
;
300 static unsigned long hash_session_info_id(uint64_t id
)
302 return hash_key_u64(&id
, lttng_ht_seed
);
305 static unsigned long hash_session_info(const struct session_info
*session_info
)
307 return hash_session_info_id(session_info
->id
);
310 static struct session_info
*get_session_info_by_id(const struct notification_thread_state
*state
,
313 struct cds_lfht_iter iter
;
314 struct cds_lfht_node
*node
;
315 lttng::urcu::read_lock_guard read_lock_guard
;
318 state
->sessions_ht
, hash_session_info_id(id
), match_session_info
, &id
, &iter
);
319 node
= cds_lfht_iter_get_node(&iter
);
323 lttng::utils::container_of(node
, &session_info::sessions_ht_node
);
325 session_info_get(session_info
);
332 static struct session_info
*get_session_info_by_name(const struct notification_thread_state
*state
,
336 const auto found
= sample_session_id_by_name(name
, &session_id
);
338 return found
? get_session_info_by_id(state
, session_id
) : nullptr;
341 static const char *notification_command_type_str(enum notification_thread_command_type type
)
344 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
345 return "REGISTER_TRIGGER";
346 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
347 return "UNREGISTER_TRIGGER";
348 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
349 return "ADD_CHANNEL";
350 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
351 return "REMOVE_CHANNEL";
352 case NOTIFICATION_COMMAND_TYPE_ADD_SESSION
:
353 return "ADD_SESSION";
354 case NOTIFICATION_COMMAND_TYPE_REMOVE_SESSION
:
355 return "REMOVE_SESSION";
356 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
357 return "SESSION_ROTATION_ONGOING";
358 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
359 return "SESSION_ROTATION_COMPLETED";
360 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
361 return "ADD_TRACER_EVENT_SOURCE";
362 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
363 return "REMOVE_TRACER_EVENT_SOURCE";
364 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
365 return "LIST_TRIGGERS";
366 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
367 return "GET_TRIGGER";
368 case NOTIFICATION_COMMAND_TYPE_QUIT
:
370 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
371 return "CLIENT_COMMUNICATION_UPDATE";
378 * Match trigger based on name and credentials only.
379 * Name duplication is NOT allowed for the same uid.
381 static int match_trigger_by_name_uid(struct cds_lfht_node
*node
, const void *key
)
384 const char *element_trigger_name
;
385 const char *key_name
;
386 enum lttng_trigger_status status
;
387 const struct lttng_credentials
*key_creds
;
388 const struct lttng_credentials
*node_creds
;
389 const struct lttng_trigger
*trigger_key
= (const struct lttng_trigger
*) key
;
390 const struct lttng_trigger_ht_element
*trigger_ht_element
=
391 caa_container_of(node
, struct lttng_trigger_ht_element
, node_by_name_uid
);
393 status
= lttng_trigger_get_name(trigger_ht_element
->trigger
, &element_trigger_name
);
394 element_trigger_name
= status
== LTTNG_TRIGGER_STATUS_OK
? element_trigger_name
: nullptr;
396 status
= lttng_trigger_get_name(trigger_key
, &key_name
);
397 key_name
= status
== LTTNG_TRIGGER_STATUS_OK
? key_name
: nullptr;
401 * Consider null names as not equal. This is to maintain backwards
402 * compatibility with pre-2.13 anonymous triggers. Multiples anonymous
403 * triggers are allowed for a given user.
405 if (!element_trigger_name
|| !key_name
) {
409 if (strcmp(element_trigger_name
, key_name
) != 0) {
413 /* Compare the owners' UIDs. */
414 key_creds
= lttng_trigger_get_credentials(trigger_key
);
415 node_creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
417 match
= lttng_credentials_is_equal_uid(key_creds
, node_creds
);
424 * Hash trigger based on name and credentials only.
426 static unsigned long hash_trigger_by_name_uid(const struct lttng_trigger
*trigger
)
428 unsigned long hash
= 0;
429 const struct lttng_credentials
*trigger_creds
;
430 const char *trigger_name
;
431 enum lttng_trigger_status status
;
433 status
= lttng_trigger_get_name(trigger
, &trigger_name
);
434 if (status
== LTTNG_TRIGGER_STATUS_OK
) {
435 hash
= hash_key_str(trigger_name
, lttng_ht_seed
);
438 trigger_creds
= lttng_trigger_get_credentials(trigger
);
439 hash
^= hash_key_ulong((void *) (unsigned long) LTTNG_OPTIONAL_GET(trigger_creds
->uid
),
445 static unsigned long hash_channel_key(struct channel_key
*key
)
447 unsigned long key_hash
= hash_key_u64(&key
->key
, lttng_ht_seed
);
448 unsigned long domain_hash
=
449 hash_key_ulong((void *) (unsigned long) key
->domain
, lttng_ht_seed
);
451 return key_hash
^ domain_hash
;
454 static unsigned long hash_client_socket(int socket
)
456 return hash_key_ulong((void *) (unsigned long) socket
, lttng_ht_seed
);
459 static unsigned long hash_client_id(notification_client_id id
)
461 return hash_key_u64(&id
, lttng_ht_seed
);
465 * Get the type of object to which a given condition applies. Bindings let
466 * the notification system evaluate a trigger's condition when a given
467 * object's state is updated.
469 * For instance, a condition bound to a channel will be evaluated everytime
470 * the channel's state is changed by a channel monitoring sample.
472 static enum lttng_object_type
get_condition_binding_object(const struct lttng_condition
*condition
)
474 switch (lttng_condition_get_type(condition
)) {
475 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
476 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
477 return LTTNG_OBJECT_TYPE_CHANNEL
;
478 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
479 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
480 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
481 return LTTNG_OBJECT_TYPE_SESSION
;
482 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
483 return LTTNG_OBJECT_TYPE_NONE
;
485 return LTTNG_OBJECT_TYPE_UNKNOWN
;
489 static void free_channel_info_rcu(struct rcu_head
*node
)
491 free(lttng::utils::container_of(node
, &channel_info::rcu_node
));
494 static void channel_info_destroy(struct channel_info
*channel_info
)
500 if (channel_info
->session_info
) {
501 session_info_remove_channel(channel_info
->session_info
, channel_info
);
502 session_info_put(channel_info
->session_info
);
504 if (channel_info
->name
) {
505 free(channel_info
->name
);
507 call_rcu(&channel_info
->rcu_node
, free_channel_info_rcu
);
510 static void free_session_info_rcu(struct rcu_head
*node
)
512 free(lttng::utils::container_of(node
, &session_info::rcu_node
));
515 /* Don't call directly, use the ref-counting mechanism. */
516 static void session_info_destroy(void *_data
)
518 struct session_info
*session_info
= (struct session_info
*) _data
;
521 LTTNG_ASSERT(session_info
);
522 if (session_info
->channel_infos_ht
) {
523 ret
= cds_lfht_destroy(session_info
->channel_infos_ht
, nullptr);
525 ERR("Failed to destroy channel information hash table");
528 lttng_session_trigger_list_destroy(session_info
->trigger_list
);
530 lttng::urcu::read_lock_guard read_lock
;
531 cds_lfht_del(session_info
->sessions_ht
, &session_info
->sessions_ht_node
);
532 free(session_info
->name
);
533 lttng_trace_archive_location_put(session_info
->last_state_sample
.rotation
.location
);
534 call_rcu(&session_info
->rcu_node
, free_session_info_rcu
);
537 static void session_info_get(struct session_info
*session_info
)
542 lttng_ref_get(&session_info
->ref
);
545 static void session_info_put(struct session_info
*session_info
)
550 lttng_ref_put(&session_info
->ref
);
553 static struct session_info
*session_info_create(uint64_t id
,
557 struct lttng_session_trigger_list
*trigger_list
,
558 struct cds_lfht
*sessions_ht
)
560 struct session_info
*session_info
;
564 session_info
= zmalloc
<struct session_info
>();
569 lttng_ref_init(&session_info
->ref
, session_info_destroy
);
571 session_info
->channel_infos_ht
= cds_lfht_new(
572 DEFAULT_HT_SIZE
, 1, 0, CDS_LFHT_AUTO_RESIZE
| CDS_LFHT_ACCOUNTING
, nullptr);
573 if (!session_info
->channel_infos_ht
) {
577 cds_lfht_node_init(&session_info
->sessions_ht_node
);
578 session_info
->id
= id
;
579 session_info
->name
= strdup(name
);
580 if (!session_info
->name
) {
584 session_info
->uid
= uid
;
585 session_info
->gid
= gid
;
586 session_info
->trigger_list
= trigger_list
;
587 session_info
->sessions_ht
= sessions_ht
;
591 session_info_put(session_info
);
595 static void session_info_add_channel(struct session_info
*session_info
,
596 struct channel_info
*channel_info
)
598 lttng::urcu::read_lock_guard read_lock
;
599 cds_lfht_add(session_info
->channel_infos_ht
,
600 hash_channel_key(&channel_info
->key
),
601 &channel_info
->session_info_channels_ht_node
);
604 static void session_info_remove_channel(struct session_info
*session_info
,
605 struct channel_info
*channel_info
)
607 lttng::urcu::read_lock_guard read_lock
;
608 cds_lfht_del(session_info
->channel_infos_ht
, &channel_info
->session_info_channels_ht_node
);
611 static struct channel_info
*channel_info_create(const char *channel_name
,
612 struct channel_key
*channel_key
,
613 uint64_t channel_capacity
,
614 struct session_info
*session_info
)
616 struct channel_info
*channel_info
= zmalloc
<struct channel_info
>();
622 cds_lfht_node_init(&channel_info
->channels_ht_node
);
623 cds_lfht_node_init(&channel_info
->session_info_channels_ht_node
);
624 memcpy(&channel_info
->key
, channel_key
, sizeof(*channel_key
));
625 channel_info
->capacity
= channel_capacity
;
627 channel_info
->name
= strdup(channel_name
);
628 if (!channel_info
->name
) {
633 * Set the references between session and channel infos:
634 * - channel_info holds a strong reference to session_info
635 * - session_info holds a weak reference to channel_info
637 session_info_get(session_info
);
638 session_info_add_channel(session_info
, channel_info
);
639 channel_info
->session_info
= session_info
;
643 channel_info_destroy(channel_info
);
647 bool notification_client_list_get(struct notification_client_list
*list
)
649 return urcu_ref_get_unless_zero(&list
->ref
);
652 static void free_notification_client_list_rcu(struct rcu_head
*node
)
654 free(caa_container_of(node
, struct notification_client_list
, rcu_node
));
657 static void notification_client_list_release(struct urcu_ref
*list_ref
)
659 struct notification_client_list
*list
=
660 lttng::utils::container_of(list_ref
, ¬ification_client_list::ref
);
661 struct notification_client_list_element
*client_list_element
, *tmp
;
663 lttng_condition_put(list
->condition
);
665 if (list
->notification_trigger_clients_ht
) {
666 lttng::urcu::read_lock_guard read_lock
;
668 cds_lfht_del(list
->notification_trigger_clients_ht
,
669 &list
->notification_trigger_clients_ht_node
);
670 list
->notification_trigger_clients_ht
= nullptr;
672 cds_list_for_each_entry_safe (client_list_element
, tmp
, &list
->clients_list
, node
) {
673 free(client_list_element
);
676 LTTNG_ASSERT(cds_list_empty(&list
->triggers_list
));
678 pthread_mutex_destroy(&list
->lock
);
679 call_rcu(&list
->rcu_node
, free_notification_client_list_rcu
);
682 static bool condition_applies_to_client(const struct lttng_condition
*condition
,
683 struct notification_client
*client
)
685 bool applies
= false;
686 struct lttng_condition_list_element
*condition_list_element
;
688 cds_list_for_each_entry (condition_list_element
, &client
->condition_list
, node
) {
689 applies
= lttng_condition_is_equal(condition_list_element
->condition
, condition
);
698 static struct notification_client_list
*
699 notification_client_list_create(struct notification_thread_state
*state
,
700 const struct lttng_condition
*condition
)
702 struct notification_client
*client
;
703 struct cds_lfht_iter iter
;
704 struct notification_client_list
*client_list
;
706 client_list
= zmalloc
<notification_client_list
>();
708 PERROR("Failed to allocate notification client list");
712 pthread_mutex_init(&client_list
->lock
, nullptr);
714 * The trigger that owns the condition has the first reference to this
717 urcu_ref_init(&client_list
->ref
);
718 cds_lfht_node_init(&client_list
->notification_trigger_clients_ht_node
);
719 CDS_INIT_LIST_HEAD(&client_list
->clients_list
);
720 CDS_INIT_LIST_HEAD(&client_list
->triggers_list
);
723 * Create a copy of the condition so that it's independent of any
724 * trigger. The client list may outlive the trigger object (which owns
725 * the condition) that is used to create it.
727 client_list
->condition
= lttng_condition_copy(condition
);
730 /* Build a list of clients to which this new condition applies. */
731 lttng::urcu::read_lock_guard read_lock
;
733 cds_lfht_for_each_entry (
734 state
->client_socket_ht
, &iter
, client
, client_socket_ht_node
) {
735 struct notification_client_list_element
*client_list_element
;
737 if (!condition_applies_to_client(condition
, client
)) {
741 client_list_element
= zmalloc
<notification_client_list_element
>();
742 if (!client_list_element
) {
743 goto error_put_client_list
;
746 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
747 client_list_element
->client
= client
;
748 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
752 client_list
->notification_trigger_clients_ht
= state
->notification_trigger_clients_ht
;
755 * Add the client list to the global list of client list.
758 lttng::urcu::read_lock_guard read_lock
;
760 cds_lfht_add_unique(state
->notification_trigger_clients_ht
,
761 lttng_condition_hash(client_list
->condition
),
762 match_client_list_condition
,
763 client_list
->condition
,
764 &client_list
->notification_trigger_clients_ht_node
);
768 error_put_client_list
:
769 notification_client_list_put(client_list
);
770 client_list
= nullptr;
776 void notification_client_list_put(struct notification_client_list
*list
)
781 return urcu_ref_put(&list
->ref
, notification_client_list_release
);
784 /* Provides a reference to the returned list. */
785 static struct notification_client_list
*
786 get_client_list_from_condition(struct notification_thread_state
*state
,
787 const struct lttng_condition
*condition
)
789 struct cds_lfht_node
*node
;
790 struct cds_lfht_iter iter
;
791 struct notification_client_list
*list
= nullptr;
793 lttng::urcu::read_lock_guard read_lock
;
794 cds_lfht_lookup(state
->notification_trigger_clients_ht
,
795 lttng_condition_hash(condition
),
796 match_client_list_condition
,
799 node
= cds_lfht_iter_get_node(&iter
);
801 list
= lttng::utils::container_of(
802 node
, ¬ification_client_list::notification_trigger_clients_ht_node
);
803 list
= notification_client_list_get(list
) ? list
: nullptr;
809 static int evaluate_channel_condition_for_client(const struct lttng_condition
*condition
,
810 struct notification_thread_state
*state
,
811 struct lttng_evaluation
**evaluation
,
816 struct cds_lfht_iter iter
;
817 struct cds_lfht_node
*node
;
818 struct channel_info
*channel_info
= nullptr;
819 struct channel_key
*channel_key
= nullptr;
820 struct channel_state_sample
*last_sample
= nullptr;
821 struct lttng_channel_trigger_list
*channel_trigger_list
= nullptr;
823 lttng::urcu::read_lock_guard read_lock
;
825 /* Find the channel associated with the condition. */
826 cds_lfht_for_each_entry (
827 state
->channel_triggers_ht
, &iter
, channel_trigger_list
, channel_triggers_ht_node
) {
828 struct lttng_trigger_list_element
*element
;
830 cds_list_for_each_entry (element
, &channel_trigger_list
->list
, node
) {
831 const struct lttng_condition
*current_condition
=
832 lttng_trigger_get_const_condition(element
->trigger
);
834 LTTNG_ASSERT(current_condition
);
835 if (!lttng_condition_is_equal(condition
, current_condition
)) {
839 /* Found the trigger, save the channel key. */
840 channel_key
= &channel_trigger_list
->channel_key
;
844 /* The channel key was found stop iteration. */
850 /* No channel found; normal exit. */
851 DBG("No known channel associated with newly subscribed-to condition");
856 /* Fetch channel info for the matching channel. */
857 cds_lfht_lookup(state
->channels_ht
,
858 hash_channel_key(channel_key
),
862 node
= cds_lfht_iter_get_node(&iter
);
864 channel_info
= caa_container_of(node
, struct channel_info
, channels_ht_node
);
866 /* Retrieve the channel's last sample, if it exists. */
867 cds_lfht_lookup(state
->channel_state_ht
,
868 hash_channel_key(channel_key
),
869 match_channel_state_sample
,
872 node
= cds_lfht_iter_get_node(&iter
);
875 caa_container_of(node
, struct channel_state_sample
, channel_state_ht_node
);
877 /* Nothing to evaluate, no sample was ever taken. Normal exit */
878 DBG("No channel sample associated with newly subscribed-to condition");
883 ret
= evaluate_buffer_condition(
884 condition
, evaluation
, state
, nullptr, last_sample
, channel_info
);
886 WARN("Fatal error occurred while evaluating a newly subscribed-to condition");
890 *session_uid
= channel_info
->session_info
->uid
;
891 *session_gid
= channel_info
->session_info
->gid
;
896 static const char *get_condition_session_name(const struct lttng_condition
*condition
)
898 const char *session_name
= nullptr;
899 enum lttng_condition_status status
;
901 switch (lttng_condition_get_type(condition
)) {
902 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
903 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
904 status
= lttng_condition_buffer_usage_get_session_name(condition
, &session_name
);
906 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
907 status
= lttng_condition_session_consumed_size_get_session_name(condition
,
910 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
911 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
913 lttng_condition_session_rotation_get_session_name(condition
, &session_name
);
918 if (status
!= LTTNG_CONDITION_STATUS_OK
) {
919 ERR("Failed to retrieve session rotation condition's session name");
926 static bool evaluate_session_rotation_ongoing_condition(const struct lttng_condition
*condition
927 __attribute__((unused
)),
928 const struct session_state_sample
*sample
)
930 return sample
->rotation
.ongoing
;
933 static bool evaluate_session_consumed_size_condition(const struct lttng_condition
*condition
,
934 const struct session_state_sample
*sample
)
937 const struct lttng_condition_session_consumed_size
*size_condition
=
938 lttng::utils::container_of(condition
,
939 <tng_condition_session_consumed_size::parent
);
941 threshold
= size_condition
->consumed_threshold_bytes
.value
;
942 DBG("Session consumed size condition being evaluated: threshold = %" PRIu64
943 ", current size = %" PRIu64
,
945 sample
->consumed_data_size
);
946 return sample
->consumed_data_size
>= threshold
;
950 * `new_state` can be NULL to indicate that we are not evaluating a
951 * state transition. A client subscribed or a trigger was registered and
952 * we wish to perform an initial evaluation.
954 static int evaluate_session_condition(const struct lttng_condition
*condition
,
955 const struct session_info
*session_info
,
956 const struct session_state_sample
*new_state
,
957 struct lttng_evaluation
**evaluation
)
960 bool previous_result
, newest_result
;
962 switch (lttng_condition_get_type(condition
)) {
963 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
965 previous_result
= evaluate_session_rotation_ongoing_condition(
966 condition
, &session_info
->last_state_sample
);
968 evaluate_session_rotation_ongoing_condition(condition
, new_state
);
970 previous_result
= false;
971 newest_result
= evaluate_session_rotation_ongoing_condition(
972 condition
, &session_info
->last_state_sample
);
975 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
977 previous_result
= evaluate_session_consumed_size_condition(
978 condition
, &session_info
->last_state_sample
);
980 evaluate_session_consumed_size_condition(condition
, new_state
);
982 previous_result
= false;
983 newest_result
= evaluate_session_consumed_size_condition(
984 condition
, &session_info
->last_state_sample
);
987 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
989 * Note that LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED is
990 * evaluated differently to only consider state transitions without regard for the
991 * initial state. This is a deliberate choice as it is unlikely that a user would
992 * expect an action to occur for a rotation that occurred long before the trigger or
993 * subscription occurred.
1000 previous_result
= !session_info
->last_state_sample
.rotation
.ongoing
;
1001 newest_result
= !new_state
->rotation
.ongoing
;
1008 if (!newest_result
|| (previous_result
== newest_result
)) {
1009 /* Not a state transition, evaluate to false. */
1014 switch (lttng_condition_get_type(condition
)) {
1015 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1017 const auto rotation_id
= new_state
? new_state
->rotation
.id
:
1018 session_info
->last_state_sample
.rotation
.id
;
1020 *evaluation
= lttng_evaluation_session_rotation_ongoing_create(rotation_id
);
1023 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1025 const auto& sample
= new_state
? *new_state
: session_info
->last_state_sample
;
1026 const auto rotation_id
= sample
.rotation
.id
;
1028 /* Callee acquires a reference to location. */
1029 *evaluation
= lttng_evaluation_session_rotation_completed_create(
1030 rotation_id
, sample
.rotation
.location
);
1033 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1035 const auto latest_session_consumed_total
= new_state
?
1036 new_state
->consumed_data_size
:
1037 session_info
->last_state_sample
.consumed_data_size
;
1039 *evaluation
= lttng_evaluation_session_consumed_size_create(
1040 latest_session_consumed_total
);
1049 ERR("Failed to create session condition evaluation: session name = `%s`",
1050 session_info
->name
);
1060 static int evaluate_condition_for_client(const struct lttng_trigger
*trigger
,
1061 const struct lttng_condition
*condition
,
1062 struct notification_client
*client
,
1063 struct notification_thread_state
*state
)
1066 struct lttng_evaluation
*evaluation
= nullptr;
1067 struct notification_client_list client_list
= {
1068 .lock
= PTHREAD_MUTEX_INITIALIZER
,
1070 .condition
= nullptr,
1071 .triggers_list
= {},
1073 .notification_trigger_clients_ht
= nullptr,
1074 .notification_trigger_clients_ht_node
= {},
1077 struct notification_client_list_element client_list_element
= {};
1078 uid_t object_uid
= 0;
1079 gid_t object_gid
= 0;
1081 LTTNG_ASSERT(trigger
);
1082 LTTNG_ASSERT(condition
);
1083 LTTNG_ASSERT(client
);
1084 LTTNG_ASSERT(state
);
1086 switch (get_condition_binding_object(condition
)) {
1087 case LTTNG_OBJECT_TYPE_SESSION
:
1089 /* Find the session associated with the condition. */
1090 const auto *session_name
= get_condition_session_name(condition
);
1091 auto session_info
= get_session_info_by_name(state
, session_name
);
1092 if (!session_info
) {
1093 /* Not an error, the session doesn't exist yet. */
1094 DBG("Session not found while evaluating session condition for client: session name = `%s`",
1100 object_uid
= session_info
->uid
;
1101 object_gid
= session_info
->gid
;
1103 ret
= evaluate_session_condition(condition
, session_info
, nullptr, &evaluation
);
1104 session_info_put(session_info
);
1107 case LTTNG_OBJECT_TYPE_CHANNEL
:
1108 ret
= evaluate_channel_condition_for_client(
1109 condition
, state
, &evaluation
, &object_uid
, &object_gid
);
1111 case LTTNG_OBJECT_TYPE_NONE
:
1112 DBG("Newly subscribed-to condition not bound to object, nothing to evaluate");
1115 case LTTNG_OBJECT_TYPE_UNKNOWN
:
1125 /* Evaluation yielded nothing. Normal exit. */
1126 DBG("Newly subscribed-to condition evaluated to false, nothing to report to client");
1132 * Create a temporary client list with the client currently
1135 cds_lfht_node_init(&client_list
.notification_trigger_clients_ht_node
);
1136 CDS_INIT_LIST_HEAD(&client_list
.clients_list
);
1138 CDS_INIT_LIST_HEAD(&client_list_element
.node
);
1139 client_list_element
.client
= client
;
1140 cds_list_add(&client_list_element
.node
, &client_list
.clients_list
);
1142 /* Send evaluation result to the newly-subscribed client. */
1143 DBG("Newly subscribed-to condition evaluated to true, notifying client");
1144 ret
= send_evaluation_to_clients(
1145 trigger
, evaluation
, &client_list
, state
, object_uid
, object_gid
);
1151 static int notification_thread_client_subscribe(struct notification_client
*client
,
1152 struct lttng_condition
*condition
,
1153 struct notification_thread_state
*state
,
1154 enum lttng_notification_channel_status
*_status
)
1157 struct notification_client_list
*client_list
= nullptr;
1158 struct lttng_condition_list_element
*condition_list_element
= nullptr;
1159 struct notification_client_list_element
*client_list_element
= nullptr;
1160 struct lttng_trigger_ht_element
*trigger_ht_element
;
1161 enum lttng_notification_channel_status status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1164 * Ensure that the client has not already subscribed to this condition
1167 cds_list_for_each_entry (condition_list_element
, &client
->condition_list
, node
) {
1168 if (lttng_condition_is_equal(condition_list_element
->condition
, condition
)) {
1169 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED
;
1174 condition_list_element
= zmalloc
<lttng_condition_list_element
>();
1175 if (!condition_list_element
) {
1179 client_list_element
= zmalloc
<notification_client_list_element
>();
1180 if (!client_list_element
) {
1186 * Add the newly-subscribed condition to the client's subscription list.
1188 CDS_INIT_LIST_HEAD(&condition_list_element
->node
);
1189 condition_list_element
->condition
= condition
;
1190 condition
= nullptr;
1191 cds_list_add(&condition_list_element
->node
, &client
->condition_list
);
1193 client_list
= get_client_list_from_condition(state
, condition_list_element
->condition
);
1196 * No notification-emiting trigger registered with this
1197 * condition. We don't evaluate the condition right away
1198 * since this trigger is not registered yet.
1200 free(client_list_element
);
1205 * The condition to which the client just subscribed is evaluated
1206 * at this point so that conditions that are already TRUE result
1207 * in a notification being sent out.
1209 * Note the iteration on all triggers which share an identical
1210 * `condition` than the one to which the client is registering. This is
1211 * done to ensure that the client receives a distinct notification for
1212 * all triggers that have a `notify` action that have this condition.
1214 pthread_mutex_lock(&client_list
->lock
);
1215 cds_list_for_each_entry (
1216 trigger_ht_element
, &client_list
->triggers_list
, client_list_trigger_node
) {
1217 if (evaluate_condition_for_client(trigger_ht_element
->trigger
,
1218 condition_list_element
->condition
,
1221 WARN("Evaluation of a condition on client subscription failed, aborting.");
1223 free(client_list_element
);
1224 pthread_mutex_unlock(&client_list
->lock
);
1228 pthread_mutex_unlock(&client_list
->lock
);
1231 * Add the client to the list of clients interested in a given trigger
1232 * if a "notification" trigger with a corresponding condition was
1235 client_list_element
->client
= client
;
1236 CDS_INIT_LIST_HEAD(&client_list_element
->node
);
1238 pthread_mutex_lock(&client_list
->lock
);
1239 cds_list_add(&client_list_element
->node
, &client_list
->clients_list
);
1240 pthread_mutex_unlock(&client_list
->lock
);
1246 notification_client_list_put(client_list
);
1248 lttng_condition_destroy(condition
);
1251 free(condition_list_element
);
1252 free(client_list_element
);
1253 lttng_condition_destroy(condition
);
1257 static int notification_thread_client_unsubscribe(struct notification_client
*client
,
1258 struct lttng_condition
*condition
,
1259 struct notification_thread_state
*state
,
1260 enum lttng_notification_channel_status
*_status
)
1262 struct notification_client_list
*client_list
;
1263 struct lttng_condition_list_element
*condition_list_element
, *condition_tmp
;
1264 struct notification_client_list_element
*client_list_element
, *client_tmp
;
1265 bool condition_found
= false;
1266 enum lttng_notification_channel_status status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
1268 /* Remove the condition from the client's condition list. */
1269 cds_list_for_each_entry_safe (
1270 condition_list_element
, condition_tmp
, &client
->condition_list
, node
) {
1271 if (!lttng_condition_is_equal(condition_list_element
->condition
, condition
)) {
1275 cds_list_del(&condition_list_element
->node
);
1277 * The caller may be iterating on the client's conditions to
1278 * tear down a client's connection. In this case, the condition
1279 * will be destroyed at the end.
1281 if (condition
!= condition_list_element
->condition
) {
1282 lttng_condition_destroy(condition_list_element
->condition
);
1284 free(condition_list_element
);
1285 condition_found
= true;
1289 if (!condition_found
) {
1290 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION
;
1295 * Remove the client from the list of clients interested the trigger
1296 * matching the condition.
1298 client_list
= get_client_list_from_condition(state
, condition
);
1303 pthread_mutex_lock(&client_list
->lock
);
1304 cds_list_for_each_entry_safe (
1305 client_list_element
, client_tmp
, &client_list
->clients_list
, node
) {
1306 if (client_list_element
->client
->id
!= client
->id
) {
1309 cds_list_del(&client_list_element
->node
);
1310 free(client_list_element
);
1313 pthread_mutex_unlock(&client_list
->lock
);
1314 notification_client_list_put(client_list
);
1315 client_list
= nullptr;
1317 lttng_condition_destroy(condition
);
1324 static void free_notification_client_rcu(struct rcu_head
*node
)
1326 free(lttng::utils::container_of(node
, ¬ification_client::rcu_node
));
1329 static void notification_client_destroy(struct notification_client
*client
)
1336 * The client object is not reachable by other threads, no need to lock
1339 if (client
->socket
>= 0) {
1340 (void) lttcomm_close_unix_sock(client
->socket
);
1341 client
->socket
= -1;
1343 client
->communication
.active
= false;
1344 lttng_payload_reset(&client
->communication
.inbound
.payload
);
1345 lttng_payload_reset(&client
->communication
.outbound
.payload
);
1346 pthread_mutex_destroy(&client
->lock
);
1347 call_rcu(&client
->rcu_node
, free_notification_client_rcu
);
1351 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1354 static struct notification_client
*get_client_from_socket(int socket
,
1355 struct notification_thread_state
*state
)
1357 struct cds_lfht_iter iter
;
1358 struct cds_lfht_node
*node
;
1359 struct notification_client
*client
= nullptr;
1361 ASSERT_RCU_READ_LOCKED();
1363 cds_lfht_lookup(state
->client_socket_ht
,
1364 hash_client_socket(socket
),
1365 match_client_socket
,
1366 (void *) (unsigned long) socket
,
1368 node
= cds_lfht_iter_get_node(&iter
);
1373 client
= caa_container_of(node
, struct notification_client
, client_socket_ht_node
);
1379 * Call with rcu_read_lock held (and hold for the lifetime of the returned
1382 static struct notification_client
*get_client_from_id(notification_client_id id
,
1383 struct notification_thread_state
*state
)
1385 struct cds_lfht_iter iter
;
1386 struct cds_lfht_node
*node
;
1387 struct notification_client
*client
= nullptr;
1389 ASSERT_RCU_READ_LOCKED();
1391 cds_lfht_lookup(state
->client_id_ht
, hash_client_id(id
), match_client_id
, &id
, &iter
);
1392 node
= cds_lfht_iter_get_node(&iter
);
1397 client
= caa_container_of(node
, struct notification_client
, client_id_ht_node
);
1402 static bool buffer_usage_condition_applies_to_channel(const struct lttng_condition
*condition
,
1403 const struct channel_info
*channel_info
)
1405 enum lttng_condition_status status
;
1406 enum lttng_domain_type condition_domain
;
1407 const char *condition_session_name
= nullptr;
1408 const char *condition_channel_name
= nullptr;
1410 status
= lttng_condition_buffer_usage_get_domain_type(condition
, &condition_domain
);
1411 LTTNG_ASSERT(status
== LTTNG_CONDITION_STATUS_OK
);
1412 if (channel_info
->key
.domain
!= condition_domain
) {
1416 status
= lttng_condition_buffer_usage_get_session_name(condition
, &condition_session_name
);
1417 LTTNG_ASSERT((status
== LTTNG_CONDITION_STATUS_OK
) && condition_session_name
);
1419 status
= lttng_condition_buffer_usage_get_channel_name(condition
, &condition_channel_name
);
1420 LTTNG_ASSERT((status
== LTTNG_CONDITION_STATUS_OK
) && condition_channel_name
);
1422 if (strcmp(channel_info
->session_info
->name
, condition_session_name
) != 0) {
1425 if (strcmp(channel_info
->name
, condition_channel_name
) != 0) {
1434 static bool trigger_applies_to_channel(const struct lttng_trigger
*trigger
,
1435 const struct channel_info
*channel_info
)
1437 const struct lttng_condition
*condition
;
1438 bool trigger_applies
;
1440 condition
= lttng_trigger_get_const_condition(trigger
);
1445 switch (lttng_condition_get_type(condition
)) {
1446 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
1447 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
1449 buffer_usage_condition_applies_to_channel(condition
, channel_info
);
1455 return trigger_applies
;
1460 /* Must be called with RCU read lock held. */
1461 static struct lttng_session_trigger_list
*
1462 get_session_trigger_list(struct notification_thread_state
*state
, const char *session_name
)
1464 struct lttng_session_trigger_list
*list
= nullptr;
1465 struct cds_lfht_node
*node
;
1466 struct cds_lfht_iter iter
;
1468 ASSERT_RCU_READ_LOCKED();
1470 cds_lfht_lookup(state
->session_triggers_ht
,
1471 hash_key_str(session_name
, lttng_ht_seed
),
1472 match_session_trigger_list
,
1475 node
= cds_lfht_iter_get_node(&iter
);
1478 * Not an error, the list of triggers applying to that session
1479 * will be initialized when the session is created.
1481 DBG("No trigger list found for session \"%s\" as it is not yet known to the notification system",
1486 list
= caa_container_of(node
, struct lttng_session_trigger_list
, session_triggers_ht_node
);
1492 * Allocate an empty lttng_session_trigger_list for the session named
1495 static struct lttng_session_trigger_list
*
1496 lttng_session_trigger_list_create(const char *session_name
, struct cds_lfht
*session_triggers_ht
)
1498 struct lttng_session_trigger_list
*list
= nullptr;
1499 char *session_name_copy
= strdup(session_name
);
1501 if (!session_name_copy
) {
1502 PERROR("Failed to allocate session name while building trigger list");
1506 list
= zmalloc
<lttng_session_trigger_list
>();
1508 PERROR("Failed to allocate session trigger list while building trigger list");
1512 list
->session_name
= session_name_copy
;
1513 CDS_INIT_LIST_HEAD(&list
->list
);
1514 cds_lfht_node_init(&list
->session_triggers_ht_node
);
1515 list
->session_triggers_ht
= session_triggers_ht
;
1517 /* Publish the list through the session_triggers_ht. */
1519 lttng::urcu::read_lock_guard read_lock
;
1520 cds_lfht_add(session_triggers_ht
,
1521 hash_key_str(session_name
, lttng_ht_seed
),
1522 &list
->session_triggers_ht_node
);
1528 static void free_session_trigger_list_rcu(struct rcu_head
*node
)
1530 struct lttng_session_trigger_list
*list
=
1531 caa_container_of(node
, struct lttng_session_trigger_list
, rcu_node
);
1533 free(list
->session_name
);
1537 static void lttng_session_trigger_list_destroy(struct lttng_session_trigger_list
*list
)
1539 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1541 /* Empty the list element by element, and then free the list itself. */
1542 cds_list_for_each_entry_safe (trigger_list_element
, tmp
, &list
->list
, node
) {
1543 cds_list_del(&trigger_list_element
->node
);
1544 free(trigger_list_element
);
1546 lttng::urcu::read_lock_guard read_lock
;
1547 /* Unpublish the list from the session_triggers_ht. */
1548 cds_lfht_del(list
->session_triggers_ht
, &list
->session_triggers_ht_node
);
1549 call_rcu(&list
->rcu_node
, free_session_trigger_list_rcu
);
1552 static int lttng_session_trigger_list_add(struct lttng_session_trigger_list
*list
,
1553 struct lttng_trigger
*trigger
)
1556 struct lttng_trigger_list_element
*new_element
= zmalloc
<lttng_trigger_list_element
>();
1562 CDS_INIT_LIST_HEAD(&new_element
->node
);
1563 new_element
->trigger
= trigger
;
1564 cds_list_add(&new_element
->node
, &list
->list
);
1569 static bool trigger_applies_to_session(const struct lttng_trigger
*trigger
,
1570 const char *session_name
)
1572 bool applies
= false;
1573 const struct lttng_condition
*condition
;
1575 condition
= lttng_trigger_get_const_condition(trigger
);
1576 switch (lttng_condition_get_type(condition
)) {
1577 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING
:
1578 case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED
:
1579 case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
:
1581 const char *condition_session_name
;
1583 condition_session_name
= get_condition_session_name(condition
);
1584 LTTNG_ASSERT(condition_session_name
);
1585 applies
= !strcmp(condition_session_name
, session_name
);
1596 * Allocate and initialize an lttng_session_trigger_list which contains
1597 * all triggers that apply to the session named 'session_name'.
1599 static struct lttng_session_trigger_list
*
1600 lttng_session_trigger_list_build(const struct notification_thread_state
*state
,
1601 const char *session_name
)
1603 int trigger_count
= 0;
1604 struct lttng_session_trigger_list
*session_trigger_list
= nullptr;
1605 struct lttng_trigger_ht_element
*trigger_ht_element
= nullptr;
1606 struct cds_lfht_iter iter
;
1608 session_trigger_list
=
1609 lttng_session_trigger_list_create(session_name
, state
->session_triggers_ht
);
1612 /* Add all triggers applying to the session named 'session_name'. */
1613 lttng::urcu::read_lock_guard read_lock
;
1615 cds_lfht_for_each_entry (state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
1618 if (!trigger_applies_to_session(trigger_ht_element
->trigger
,
1623 ret
= lttng_session_trigger_list_add(session_trigger_list
,
1624 trigger_ht_element
->trigger
);
1633 DBG("Found %i triggers that apply to newly created session", trigger_count
);
1634 return session_trigger_list
;
1636 lttng_session_trigger_list_destroy(session_trigger_list
);
1640 static struct session_info
*create_and_publish_session_info(struct notification_thread_state
*state
,
1646 struct session_info
*session
= nullptr;
1647 struct lttng_session_trigger_list
*trigger_list
;
1649 lttng::urcu::read_lock_guard read_lock
;
1650 trigger_list
= lttng_session_trigger_list_build(state
, name
);
1651 if (!trigger_list
) {
1655 session
= session_info_create(id
, name
, uid
, gid
, trigger_list
, state
->sessions_ht
);
1657 ERR("Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)",
1661 lttng_session_trigger_list_destroy(trigger_list
);
1665 /* Transferred ownership to the new session. */
1666 trigger_list
= nullptr;
1668 if (cds_lfht_add_unique(state
->sessions_ht
,
1669 hash_session_info(session
),
1672 &session
->sessions_ht_node
) != &session
->sessions_ht_node
) {
1673 ERR("Duplicate session found: name = `%s`, id = %" PRIu64
, name
, id
);
1679 session_info_put(session
);
1683 static int handle_notification_thread_command_add_channel(struct notification_thread_state
*state
,
1684 uint64_t session_id
,
1685 const char *channel_name
,
1686 enum lttng_domain_type channel_domain
,
1687 uint64_t channel_key_int
,
1688 uint64_t channel_capacity
,
1689 enum lttng_error_code
*cmd_result
)
1691 struct cds_list_head trigger_list
;
1692 struct channel_info
*new_channel_info
= nullptr;
1693 struct channel_key channel_key
= {
1694 .key
= channel_key_int
,
1695 .domain
= channel_domain
,
1697 struct lttng_channel_trigger_list
*channel_trigger_list
= nullptr;
1698 struct lttng_trigger_ht_element
*trigger_ht_element
= nullptr;
1699 int trigger_count
= 0;
1700 struct cds_lfht_iter iter
;
1701 struct session_info
*session_info
= nullptr;
1702 lttng::urcu::read_lock_guard read_lock
;
1704 DBG("Adding channel: channel name = `%s`, session id = %" PRIu64
", channel key = %" PRIu64
1709 lttng_domain_type_str(channel_domain
));
1711 CDS_INIT_LIST_HEAD(&trigger_list
);
1713 session_info
= get_session_info_by_id(state
, session_id
);
1714 if (!session_info
) {
1715 /* Fatal logic error. */
1716 ERR("Failed to find session while adding channel: session id = %" PRIu64
,
1722 channel_info_create(channel_name
, &channel_key
, channel_capacity
, session_info
);
1723 if (!new_channel_info
) {
1727 /* Build a list of all triggers applying to the new channel. */
1728 cds_lfht_for_each_entry (state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
1729 struct lttng_trigger_list_element
*new_element
;
1731 if (!trigger_applies_to_channel(trigger_ht_element
->trigger
, new_channel_info
)) {
1735 new_element
= zmalloc
<lttng_trigger_list_element
>();
1739 CDS_INIT_LIST_HEAD(&new_element
->node
);
1740 new_element
->trigger
= trigger_ht_element
->trigger
;
1741 cds_list_add(&new_element
->node
, &trigger_list
);
1745 DBG("Found %i triggers that apply to newly added channel", trigger_count
);
1746 channel_trigger_list
= zmalloc
<lttng_channel_trigger_list
>();
1747 if (!channel_trigger_list
) {
1750 channel_trigger_list
->channel_key
= new_channel_info
->key
;
1751 CDS_INIT_LIST_HEAD(&channel_trigger_list
->list
);
1752 cds_lfht_node_init(&channel_trigger_list
->channel_triggers_ht_node
);
1753 cds_list_splice(&trigger_list
, &channel_trigger_list
->list
);
1755 /* Add channel to the channel_ht which owns the channel_infos. */
1756 cds_lfht_add(state
->channels_ht
,
1757 hash_channel_key(&new_channel_info
->key
),
1758 &new_channel_info
->channels_ht_node
);
1760 * Add the list of triggers associated with this channel to the
1761 * channel_triggers_ht.
1763 cds_lfht_add(state
->channel_triggers_ht
,
1764 hash_channel_key(&new_channel_info
->key
),
1765 &channel_trigger_list
->channel_triggers_ht_node
);
1766 session_info_put(session_info
);
1767 *cmd_result
= LTTNG_OK
;
1770 channel_info_destroy(new_channel_info
);
1771 session_info_put(session_info
);
1775 static int handle_notification_thread_command_add_session(struct notification_thread_state
*state
,
1776 uint64_t session_id
,
1777 const char *session_name
,
1780 enum lttng_error_code
*cmd_result
)
1784 DBG("Adding session: session name = `%s`, session id = %" PRIu64
1785 ", session uid = %d, session gid = %d",
1791 auto session
= create_and_publish_session_info(
1792 state
, session_id
, session_name
, session_uid
, session_gid
);
1794 PERROR("Failed to add session: session name = `%s`, session id = %" PRIu64
1795 ", session uid = %d, session gid = %d",
1801 *cmd_result
= LTTNG_ERR_NOMEM
;
1806 * Note that the reference to `session` is not released; this reference is
1807 * the "global" reference that is used to allow look-ups. This reference will
1808 * only be released when the session is removed. See
1809 * handle_notification_thread_command_remove_session.
1812 *cmd_result
= LTTNG_OK
;
1818 handle_notification_thread_command_remove_session(struct notification_thread_state
*state
,
1819 uint64_t session_id
,
1820 enum lttng_error_code
*cmd_result
)
1824 DBG("Removing session: session id = %" PRIu64
, session_id
);
1826 auto session
= get_session_info_by_id(state
, session_id
);
1828 ERR("Failed to remove session: session id = %" PRIu64
, session_id
);
1830 *cmd_result
= LTTNG_ERR_NO_SESSION
;
1834 /* Release the reference returned by the look-up, and then release the global reference. */
1835 session_info_put(session
);
1836 session_info_put(session
);
1838 *cmd_result
= LTTNG_OK
;
1843 static void free_channel_trigger_list_rcu(struct rcu_head
*node
)
1845 free(caa_container_of(node
, struct lttng_channel_trigger_list
, rcu_node
));
1848 static void free_channel_state_sample_rcu(struct rcu_head
*node
)
1850 free(caa_container_of(node
, struct channel_state_sample
, rcu_node
));
1854 handle_notification_thread_command_remove_channel(struct notification_thread_state
*state
,
1855 uint64_t channel_key
,
1856 enum lttng_domain_type domain
,
1857 enum lttng_error_code
*cmd_result
)
1859 struct cds_lfht_node
*node
;
1860 struct cds_lfht_iter iter
;
1861 struct lttng_channel_trigger_list
*trigger_list
;
1862 struct lttng_trigger_list_element
*trigger_list_element
, *tmp
;
1863 struct channel_key key
= { .key
= channel_key
, .domain
= domain
};
1864 struct channel_info
*channel_info
;
1866 DBG("Removing channel key = %" PRIu64
" in %s domain",
1868 lttng_domain_type_str(domain
));
1870 lttng::urcu::read_lock_guard read_lock
;
1872 cds_lfht_lookup(state
->channel_triggers_ht
,
1873 hash_channel_key(&key
),
1874 match_channel_trigger_list
,
1877 node
= cds_lfht_iter_get_node(&iter
);
1879 * There is a severe internal error if we are being asked to remove a
1880 * channel that doesn't exist.
1883 ERR("Channel being removed is unknown to the notification thread");
1887 /* Free the list of triggers associated with this channel. */
1889 caa_container_of(node
, struct lttng_channel_trigger_list
, channel_triggers_ht_node
);
1890 cds_list_for_each_entry_safe (trigger_list_element
, tmp
, &trigger_list
->list
, node
) {
1891 cds_list_del(&trigger_list_element
->node
);
1892 free(trigger_list_element
);
1894 cds_lfht_del(state
->channel_triggers_ht
, node
);
1895 call_rcu(&trigger_list
->rcu_node
, free_channel_trigger_list_rcu
);
1897 /* Free sampled channel state. */
1898 cds_lfht_lookup(state
->channel_state_ht
,
1899 hash_channel_key(&key
),
1900 match_channel_state_sample
,
1903 node
= cds_lfht_iter_get_node(&iter
);
1905 * This is expected to be NULL if the channel is destroyed before we
1906 * received a sample.
1909 struct channel_state_sample
*sample
=
1910 caa_container_of(node
, struct channel_state_sample
, channel_state_ht_node
);
1912 cds_lfht_del(state
->channel_state_ht
, node
);
1913 call_rcu(&sample
->rcu_node
, free_channel_state_sample_rcu
);
1916 /* Remove the channel from the channels_ht and free it. */
1918 state
->channels_ht
, hash_channel_key(&key
), match_channel_info
, &key
, &iter
);
1919 node
= cds_lfht_iter_get_node(&iter
);
1921 channel_info
= caa_container_of(node
, struct channel_info
, channels_ht_node
);
1922 cds_lfht_del(state
->channels_ht
, node
);
1923 channel_info_destroy(channel_info
);
1925 *cmd_result
= LTTNG_OK
;
1930 handle_notification_thread_command_session_rotation(struct notification_thread_state
*state
,
1931 enum notification_thread_command_type cmd_type
,
1932 uint64_t session_id
,
1933 uint64_t trace_archive_chunk_id
,
1934 struct lttng_trace_archive_location
*location
,
1935 enum lttng_error_code
*_cmd_result
)
1938 enum lttng_error_code cmd_result
= LTTNG_OK
;
1939 struct lttng_session_trigger_list
*trigger_list
;
1940 struct lttng_trigger_list_element
*trigger_list_element
;
1941 struct session_info
*session_info
;
1942 struct lttng_credentials session_creds
;
1943 struct session_state_sample new_session_state
;
1945 lttng::urcu::read_lock_guard read_lock
;
1947 session_info
= get_session_info_by_id(state
, session_id
);
1948 if (!session_info
) {
1949 /* Fatal logic error. */
1950 ERR("Failed to find session while handling rotation state change: session id = %" PRIu64
,
1953 cmd_result
= LTTNG_ERR_FATAL
;
1957 new_session_state
= session_info
->last_state_sample
;
1959 lttng_trace_archive_location_get(location
);
1960 new_session_state
.rotation
.location
= location
;
1962 new_session_state
.rotation
.location
= nullptr;
1966 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session_info
->uid
),
1967 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session_info
->gid
),
1970 new_session_state
.rotation
.ongoing
= cmd_type
==
1971 NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
;
1972 new_session_state
.rotation
.id
= trace_archive_chunk_id
;
1974 trigger_list
= get_session_trigger_list(state
, session_info
->name
);
1975 LTTNG_ASSERT(trigger_list
);
1977 cds_list_for_each_entry (trigger_list_element
, &trigger_list
->list
, node
) {
1978 const struct lttng_condition
*condition
;
1979 struct lttng_trigger
*trigger
;
1980 struct notification_client_list
*client_list
;
1981 struct lttng_evaluation
*evaluation
= nullptr;
1982 enum action_executor_status executor_status
;
1984 trigger
= trigger_list_element
->trigger
;
1985 condition
= lttng_trigger_get_const_condition(trigger
);
1986 LTTNG_ASSERT(condition
);
1988 ret
= evaluate_session_condition(
1989 condition
, session_info
, &new_session_state
, &evaluation
);
1992 cmd_result
= LTTNG_ERR_NOMEM
;
2001 * Ownership of `evaluation` transferred to the action executor
2002 * no matter the result. The callee acquires a reference to the
2003 * client list: we can release our own.
2005 client_list
= get_client_list_from_condition(state
, condition
);
2006 executor_status
= action_executor_enqueue_trigger(
2007 state
->executor
, trigger
, evaluation
, &session_creds
, client_list
);
2008 notification_client_list_put(client_list
);
2009 evaluation
= nullptr;
2010 switch (executor_status
) {
2011 case ACTION_EXECUTOR_STATUS_OK
:
2013 case ACTION_EXECUTOR_STATUS_ERROR
:
2014 case ACTION_EXECUTOR_STATUS_INVALID
:
2016 * TODO Add trigger identification (name/id) when
2017 * it is added to the API.
2019 ERR("Fatal error occurred while enqueuing action associated with session rotation trigger");
2022 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
2024 * TODO Add trigger identification (name/id) when
2025 * it is added to the API.
2027 * Not a fatal error.
2029 WARN("No space left when enqueuing action associated with session rotation trigger");
2039 /* Ownership of new_session_state::location is transferred. */
2040 lttng_trace_archive_location_put(session_info
->last_state_sample
.rotation
.location
);
2041 session_info
->last_state_sample
= new_session_state
;
2044 session_info_put(session_info
);
2045 *_cmd_result
= cmd_result
;
2050 handle_notification_thread_command_add_tracer_event_source(struct notification_thread_state
*state
,
2051 int tracer_event_source_fd
,
2052 enum lttng_domain_type domain_type
,
2053 enum lttng_error_code
*_cmd_result
)
2056 enum lttng_error_code cmd_result
= LTTNG_OK
;
2057 struct notification_event_tracer_event_source_element
*element
= nullptr;
2059 element
= zmalloc
<notification_event_tracer_event_source_element
>();
2061 cmd_result
= LTTNG_ERR_NOMEM
;
2066 element
->fd
= tracer_event_source_fd
;
2067 element
->domain
= domain_type
;
2069 cds_list_add(&element
->node
, &state
->tracer_event_sources_list
);
2071 DBG3("Adding tracer event source fd to poll set: tracer_event_source_fd = %d, domain = '%s'",
2072 tracer_event_source_fd
,
2073 lttng_domain_type_str(domain_type
));
2075 /* Adding the read side pipe to the event poll. */
2076 ret
= lttng_poll_add(&state
->events
, tracer_event_source_fd
, LPOLLPRI
| LPOLLIN
);
2078 ERR("Failed to add tracer event source to poll set: tracer_event_source_fd = %d, domain = '%s'",
2079 tracer_event_source_fd
,
2080 lttng_domain_type_str(element
->domain
));
2081 cds_list_del(&element
->node
);
2086 element
->is_fd_in_poll_set
= true;
2089 *_cmd_result
= cmd_result
;
2093 static int drain_event_notifier_notification_pipe(struct notification_thread_state
*state
,
2095 enum lttng_domain_type domain
)
2097 struct lttng_poll_event events
= {};
2100 ret
= lttng_poll_create(&events
, 1, LTTNG_CLOEXEC
);
2102 ERR("Error creating lttng_poll_event");
2106 ret
= lttng_poll_add(&events
, pipe
, LPOLLIN
);
2108 ERR("Error adding fd event notifier notification pipe to lttng_poll_event: fd = %d",
2115 * Continue to consume notifications as long as there are new
2116 * ones coming in. The tracer has been asked to stop producing
2119 * LPOLLIN is explicitly checked since LPOLLHUP is implicitly
2120 * monitored (on Linux, at least) and will be returned when
2121 * the pipe is closed but empty.
2123 ret
= lttng_poll_wait_interruptible(&events
, 0);
2124 if (ret
== 0 || (LTTNG_POLL_GETEV(&events
, 0) & LPOLLIN
) == 0) {
2125 /* No more notification to be read on this pipe. */
2128 } else if (ret
< 0) {
2129 PERROR("Failed on lttng_poll_wait_interruptible() call");
2134 ret
= handle_one_event_notifier_notification(state
, pipe
, domain
);
2136 ERR("Error consuming an event notifier notification from pipe: fd = %d",
2141 lttng_poll_clean(&events
);
2145 static struct notification_event_tracer_event_source_element
*
2146 find_tracer_event_source_element(struct notification_thread_state
*state
,
2147 int tracer_event_source_fd
)
2149 struct notification_event_tracer_event_source_element
*source_element
;
2151 cds_list_for_each_entry (source_element
, &state
->tracer_event_sources_list
, node
) {
2152 if (source_element
->fd
== tracer_event_source_fd
) {
2157 source_element
= nullptr;
2159 return source_element
;
2162 static int remove_tracer_event_source_from_pollset(
2163 struct notification_thread_state
*state
,
2164 struct notification_event_tracer_event_source_element
*source_element
)
2168 LTTNG_ASSERT(source_element
->is_fd_in_poll_set
);
2170 DBG3("Removing tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2172 lttng_domain_type_str(source_element
->domain
));
2174 /* Removing the fd from the event poll set. */
2175 ret
= lttng_poll_del(&state
->events
, source_element
->fd
);
2177 ERR("Failed to remove tracer event source from poll set: tracer_event_source_fd = %d, domain = '%s'",
2179 lttng_domain_type_str(source_element
->domain
));
2184 source_element
->is_fd_in_poll_set
= false;
2187 * Force the notification thread to restart the poll() loop to ensure
2188 * that any events from the removed fd are removed.
2190 state
->restart_poll
= true;
2192 ret
= drain_event_notifier_notification_pipe(
2193 state
, source_element
->fd
, source_element
->domain
);
2195 ERR("Error draining event notifier notification: tracer_event_source_fd = %d, domain = %s",
2197 lttng_domain_type_str(source_element
->domain
));
2206 int handle_notification_thread_tracer_event_source_died(struct notification_thread_state
*state
,
2207 int tracer_event_source_fd
)
2210 struct notification_event_tracer_event_source_element
*source_element
;
2212 source_element
= find_tracer_event_source_element(state
, tracer_event_source_fd
);
2214 LTTNG_ASSERT(source_element
);
2216 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2218 ERR("Failed to remove dead tracer event source from poll set");
2224 static int handle_notification_thread_command_remove_tracer_event_source(
2225 struct notification_thread_state
*state
,
2226 int tracer_event_source_fd
,
2227 enum lttng_error_code
*_cmd_result
)
2230 enum lttng_error_code cmd_result
= LTTNG_OK
;
2231 struct notification_event_tracer_event_source_element
*source_element
= nullptr;
2233 source_element
= find_tracer_event_source_element(state
, tracer_event_source_fd
);
2235 LTTNG_ASSERT(source_element
);
2237 /* Remove the tracer source from the list. */
2238 cds_list_del(&source_element
->node
);
2240 if (!source_element
->is_fd_in_poll_set
) {
2241 /* Skip the poll set removal. */
2245 ret
= remove_tracer_event_source_from_pollset(state
, source_element
);
2247 ERR("Failed to remove tracer event source from poll set");
2248 cmd_result
= LTTNG_ERR_FATAL
;
2252 free(source_element
);
2253 *_cmd_result
= cmd_result
;
2258 handle_notification_thread_command_list_triggers(struct notification_thread_handle
*handle
2259 __attribute__((unused
)),
2260 struct notification_thread_state
*state
,
2262 struct lttng_triggers
**triggers
,
2263 enum lttng_error_code
*_cmd_result
)
2266 enum lttng_error_code cmd_result
= LTTNG_OK
;
2267 struct cds_lfht_iter iter
;
2268 struct lttng_trigger_ht_element
*trigger_ht_element
;
2269 struct lttng_triggers
*local_triggers
= nullptr;
2270 const struct lttng_credentials
*creds
;
2272 lttng::urcu::read_lock_guard read_lock
;
2274 local_triggers
= lttng_triggers_create();
2275 if (!local_triggers
) {
2276 /* Not a fatal error. */
2277 cmd_result
= LTTNG_ERR_NOMEM
;
2281 cds_lfht_for_each_entry (state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
2283 * Only return the triggers to which the client has access.
2284 * The root user has visibility over all triggers.
2286 creds
= lttng_trigger_get_credentials(trigger_ht_element
->trigger
);
2287 if (client_uid
!= lttng_credentials_get_uid(creds
) && client_uid
!= 0) {
2291 ret
= lttng_triggers_add(local_triggers
, trigger_ht_element
->trigger
);
2293 /* Not a fatal error. */
2295 cmd_result
= LTTNG_ERR_NOMEM
;
2300 /* Transferring ownership to the caller. */
2301 *triggers
= local_triggers
;
2302 local_triggers
= nullptr;
2305 lttng_triggers_destroy(local_triggers
);
2306 *_cmd_result
= cmd_result
;
2310 static inline void get_trigger_info_for_log(const struct lttng_trigger
*trigger
,
2311 const char **trigger_name
,
2312 uid_t
*trigger_owner_uid
)
2314 enum lttng_trigger_status trigger_status
;
2316 trigger_status
= lttng_trigger_get_name(trigger
, trigger_name
);
2317 switch (trigger_status
) {
2318 case LTTNG_TRIGGER_STATUS_OK
:
2320 case LTTNG_TRIGGER_STATUS_UNSET
:
2321 *trigger_name
= "(anonymous)";
2327 trigger_status
= lttng_trigger_get_owner_uid(trigger
, trigger_owner_uid
);
2328 LTTNG_ASSERT(trigger_status
== LTTNG_TRIGGER_STATUS_OK
);
2331 static int handle_notification_thread_command_get_trigger(struct notification_thread_state
*state
,
2332 const struct lttng_trigger
*trigger
,
2333 struct lttng_trigger
**registered_trigger
,
2334 enum lttng_error_code
*_cmd_result
)
2337 struct cds_lfht_iter iter
;
2338 struct lttng_trigger_ht_element
*trigger_ht_element
;
2339 enum lttng_error_code cmd_result
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
2340 const char *trigger_name
;
2341 uid_t trigger_owner_uid
;
2344 lttng::urcu::read_lock_guard read_lock
;
2346 cds_lfht_for_each_entry (state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
2347 if (lttng_trigger_is_equal(trigger
, trigger_ht_element
->trigger
)) {
2348 /* Take one reference on the return trigger. */
2349 *registered_trigger
= trigger_ht_element
->trigger
;
2350 lttng_trigger_get(*registered_trigger
);
2352 cmd_result
= LTTNG_OK
;
2358 /* Not a fatal error if the trigger is not found. */
2359 get_trigger_info_for_log(trigger
, &trigger_name
, &trigger_owner_uid
);
2360 DBG("Failed to retrieve registered version of trigger: trigger name = '%s', trigger owner uid = %d",
2362 (int) trigger_owner_uid
);
2367 *_cmd_result
= cmd_result
;
2371 static bool condition_is_supported(struct lttng_condition
*condition
)
2375 switch (lttng_condition_get_type(condition
)) {
2376 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
2377 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
2380 enum lttng_domain_type domain
;
2382 ret
= lttng_condition_buffer_usage_get_domain_type(condition
, &domain
);
2383 LTTNG_ASSERT(ret
== 0);
2385 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2386 is_supported
= true;
2391 * Older kernel tracers don't expose the API to monitor their
2392 * buffers. Therefore, we reject triggers that require that
2393 * mechanism to be available to be evaluated.
2395 * Assume unsupported on error.
2397 is_supported
= kernel_supports_ring_buffer_snapshot_sample_positions() == 1;
2400 case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES
:
2402 const struct lttng_event_rule
*event_rule
;
2403 enum lttng_domain_type domain
;
2404 const enum lttng_condition_status status
=
2405 lttng_condition_event_rule_matches_get_rule(condition
, &event_rule
);
2407 LTTNG_ASSERT(status
== LTTNG_CONDITION_STATUS_OK
);
2409 domain
= lttng_event_rule_get_domain_type(event_rule
);
2410 if (domain
!= LTTNG_DOMAIN_KERNEL
) {
2411 is_supported
= true;
2416 * Older kernel tracers can't emit notification. Therefore, we
2417 * reject triggers that require that mechanism to be available
2420 * Assume unsupported on error.
2422 is_supported
= kernel_supports_event_notifiers() == 1;
2426 is_supported
= true;
2429 return is_supported
;
2432 /* Must be called with RCU read lock held. */
2433 static int bind_trigger_to_matching_session(struct lttng_trigger
*trigger
,
2434 struct notification_thread_state
*state
)
2437 const struct lttng_condition
*condition
;
2438 const char *session_name
;
2439 struct lttng_session_trigger_list
*trigger_list
;
2441 ASSERT_RCU_READ_LOCKED();
2443 condition
= lttng_trigger_get_const_condition(trigger
);
2444 session_name
= get_condition_session_name(condition
);
2446 trigger_list
= get_session_trigger_list(state
, session_name
);
2447 if (!trigger_list
) {
2448 DBG("Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system",
2453 DBG("Newly registered trigger bound to session \"%s\"", session_name
);
2454 ret
= lttng_session_trigger_list_add(trigger_list
, trigger
);
2459 /* Must be called with RCU read lock held. */
2460 static int bind_trigger_to_matching_channels(struct lttng_trigger
*trigger
,
2461 struct notification_thread_state
*state
)
2464 struct cds_lfht_node
*node
;
2465 struct cds_lfht_iter iter
;
2466 struct channel_info
*channel
;
2468 ASSERT_RCU_READ_LOCKED();
2470 cds_lfht_for_each_entry (state
->channels_ht
, &iter
, channel
, channels_ht_node
) {
2471 struct lttng_trigger_list_element
*trigger_list_element
;
2472 struct lttng_channel_trigger_list
*trigger_list
;
2473 struct cds_lfht_iter lookup_iter
;
2475 if (!trigger_applies_to_channel(trigger
, channel
)) {
2479 cds_lfht_lookup(state
->channel_triggers_ht
,
2480 hash_channel_key(&channel
->key
),
2481 match_channel_trigger_list
,
2484 node
= cds_lfht_iter_get_node(&lookup_iter
);
2486 trigger_list
= caa_container_of(
2487 node
, struct lttng_channel_trigger_list
, channel_triggers_ht_node
);
2489 trigger_list_element
= zmalloc
<lttng_trigger_list_element
>();
2490 if (!trigger_list_element
) {
2494 CDS_INIT_LIST_HEAD(&trigger_list_element
->node
);
2495 trigger_list_element
->trigger
= trigger
;
2496 cds_list_add(&trigger_list_element
->node
, &trigger_list
->list
);
2497 DBG("Newly registered trigger bound to channel \"%s\"", channel
->name
);
2503 static bool is_trigger_action_notify(const struct lttng_trigger
*trigger
)
2505 bool is_notify
= false;
2506 const struct lttng_action
*action
= lttng_trigger_get_const_action(trigger
);
2507 enum lttng_action_type action_type
;
2509 LTTNG_ASSERT(action
);
2510 action_type
= lttng_action_get_type(action
);
2511 if (action_type
== LTTNG_ACTION_TYPE_NOTIFY
) {
2514 } else if (action_type
!= LTTNG_ACTION_TYPE_LIST
) {
2518 for (auto inner_action
: lttng::ctl::const_action_list_view(action
)) {
2519 if (lttng_action_get_type(inner_action
) == LTTNG_ACTION_TYPE_NOTIFY
) {
2529 static bool trigger_name_taken(struct notification_thread_state
*state
,
2530 const struct lttng_trigger
*trigger
)
2532 struct cds_lfht_iter iter
;
2535 * No duplicata is allowed in the triggers_by_name_uid_ht.
2536 * The match is done against the trigger name and uid.
2538 cds_lfht_lookup(state
->triggers_by_name_uid_ht
,
2539 hash_trigger_by_name_uid(trigger
),
2540 match_trigger_by_name_uid
,
2543 return !!cds_lfht_iter_get_node(&iter
);
2546 static enum lttng_error_code
generate_trigger_name(struct notification_thread_state
*state
,
2547 struct lttng_trigger
*trigger
,
2550 enum lttng_error_code ret_code
= LTTNG_OK
;
2552 enum lttng_trigger_status status
;
2556 lttng_trigger_generate_name(trigger
, state
->trigger_id
.name_offset
++);
2558 /* The only reason this can fail right now. */
2559 ret_code
= LTTNG_ERR_NOMEM
;
2563 status
= lttng_trigger_get_name(trigger
, name
);
2564 LTTNG_ASSERT(status
== LTTNG_TRIGGER_STATUS_OK
);
2566 taken
= trigger_name_taken(state
, trigger
);
2567 } while (taken
|| state
->trigger_id
.name_offset
== UINT64_MAX
);
2573 notif_thread_state_remove_trigger_ht_elem(struct notification_thread_state
*state
,
2574 struct lttng_trigger_ht_element
*trigger_ht_element
)
2576 LTTNG_ASSERT(state
);
2577 LTTNG_ASSERT(trigger_ht_element
);
2579 cds_lfht_del(state
->triggers_ht
, &trigger_ht_element
->node
);
2580 cds_lfht_del(state
->triggers_by_name_uid_ht
, &trigger_ht_element
->node_by_name_uid
);
2583 static enum lttng_error_code
setup_tracer_notifier(struct notification_thread_state
*state
,
2584 struct lttng_trigger
*trigger
)
2586 enum lttng_error_code ret
;
2587 enum event_notifier_error_accounting_status error_accounting_status
;
2588 struct cds_lfht_node
*node
;
2589 uint64_t error_counter_index
= 0;
2590 struct lttng_condition
*condition
= lttng_trigger_get_condition(trigger
);
2591 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
= nullptr;
2593 trigger_tokens_ht_element
= zmalloc
<notification_trigger_tokens_ht_element
>();
2594 if (!trigger_tokens_ht_element
) {
2595 ret
= LTTNG_ERR_NOMEM
;
2599 /* Add trigger token to the trigger_tokens_ht. */
2600 cds_lfht_node_init(&trigger_tokens_ht_element
->node
);
2601 trigger_tokens_ht_element
->token
= LTTNG_OPTIONAL_GET(trigger
->tracer_token
);
2602 trigger_tokens_ht_element
->trigger
= trigger
;
2604 node
= cds_lfht_add_unique(state
->trigger_tokens_ht
,
2605 hash_key_u64(&trigger_tokens_ht_element
->token
, lttng_ht_seed
),
2606 match_trigger_token
,
2607 &trigger_tokens_ht_element
->token
,
2608 &trigger_tokens_ht_element
->node
);
2609 if (node
!= &trigger_tokens_ht_element
->node
) {
2610 ret
= LTTNG_ERR_TRIGGER_EXISTS
;
2611 goto error_free_ht_element
;
2614 error_accounting_status
= event_notifier_error_accounting_register_event_notifier(
2615 trigger
, &error_counter_index
);
2616 if (error_accounting_status
!= EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK
) {
2617 if (error_accounting_status
==
2618 EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE
) {
2619 DBG("Trigger list error accounting counter full.");
2620 ret
= LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING_FULL
;
2622 ERR("Error registering trigger for error accounting");
2623 ret
= LTTNG_ERR_EVENT_NOTIFIER_REGISTRATION
;
2626 goto error_remove_ht_element
;
2629 lttng_condition_event_rule_matches_set_error_counter_index(condition
, error_counter_index
);
2634 error_remove_ht_element
:
2635 cds_lfht_del(state
->trigger_tokens_ht
, &trigger_tokens_ht_element
->node
);
2636 error_free_ht_element
:
2637 free(trigger_tokens_ht_element
);
2643 * FIXME A client's credentials are not checked when registering a trigger.
2645 * The effects of this are benign since:
2646 * - The client will succeed in registering the trigger, as it is valid,
2647 * - The trigger will, internally, be bound to the channel/session,
2648 * - The notifications will not be sent since the client's credentials
2649 * are checked against the channel at that moment.
2651 * If this function returns a non-zero value, it means something is
2652 * fundamentally broken and the whole subsystem/thread will be torn down.
2654 * If a non-fatal error occurs, just set the cmd_result to the appropriate
2658 handle_notification_thread_command_register_trigger(struct notification_thread_state
*state
,
2659 struct lttng_trigger
*trigger
,
2660 bool is_trigger_anonymous
,
2661 enum lttng_error_code
*cmd_result
)
2664 struct lttng_condition
*condition
;
2665 struct notification_client_list
*client_list
= nullptr;
2666 struct lttng_trigger_ht_element
*trigger_ht_element
= nullptr;
2667 struct cds_lfht_node
*node
;
2668 const char *trigger_name
;
2669 bool free_trigger
= true;
2670 struct lttng_evaluation
*evaluation
= nullptr;
2671 struct lttng_credentials object_creds
;
2674 enum action_executor_status executor_status
;
2675 const uint64_t trigger_tracer_token
= state
->trigger_id
.next_tracer_token
++;
2677 lttng::urcu::read_lock_guard read_lock
;
2679 /* Set the trigger's tracer token. */
2680 lttng_trigger_set_tracer_token(trigger
, trigger_tracer_token
);
2682 if (!is_trigger_anonymous
) {
2683 if (lttng_trigger_get_name(trigger
, &trigger_name
) == LTTNG_TRIGGER_STATUS_UNSET
) {
2684 const enum lttng_error_code ret_code
=
2685 generate_trigger_name(state
, trigger
, &trigger_name
);
2687 if (ret_code
!= LTTNG_OK
) {
2690 *cmd_result
= ret_code
;
2693 } else if (trigger_name_taken(state
, trigger
)) {
2694 /* Not a fatal error. */
2695 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2700 trigger_name
= "(anonymous)";
2703 condition
= lttng_trigger_get_condition(trigger
);
2704 LTTNG_ASSERT(condition
);
2706 /* Some conditions require tracers to implement a minimal ABI version. */
2707 if (!condition_is_supported(condition
)) {
2708 *cmd_result
= LTTNG_ERR_NOT_SUPPORTED
;
2712 trigger_ht_element
= zmalloc
<lttng_trigger_ht_element
>();
2713 if (!trigger_ht_element
) {
2718 /* Add trigger to the trigger_ht. */
2719 cds_lfht_node_init(&trigger_ht_element
->node
);
2720 cds_lfht_node_init(&trigger_ht_element
->node_by_name_uid
);
2721 trigger_ht_element
->trigger
= trigger
;
2723 node
= cds_lfht_add_unique(state
->triggers_ht
,
2724 lttng_condition_hash(condition
),
2727 &trigger_ht_element
->node
);
2728 if (node
!= &trigger_ht_element
->node
) {
2729 /* Not a fatal error, simply report it to the client. */
2730 *cmd_result
= LTTNG_ERR_TRIGGER_EXISTS
;
2731 goto error_free_ht_element
;
2734 node
= cds_lfht_add_unique(state
->triggers_by_name_uid_ht
,
2735 hash_trigger_by_name_uid(trigger
),
2736 match_trigger_by_name_uid
,
2738 &trigger_ht_element
->node_by_name_uid
);
2739 if (node
!= &trigger_ht_element
->node_by_name_uid
) {
2740 /* Internal error: add to triggers_ht should have failed. */
2742 goto error_free_ht_element
;
2745 /* From this point consider the trigger registered. */
2746 lttng_trigger_set_as_registered(trigger
);
2749 * Some triggers might need a tracer notifier depending on its
2750 * condition and actions.
2752 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
2753 enum lttng_error_code error_code
;
2755 error_code
= setup_tracer_notifier(state
, trigger
);
2756 if (error_code
!= LTTNG_OK
) {
2757 notif_thread_state_remove_trigger_ht_elem(state
, trigger_ht_element
);
2758 if (error_code
== LTTNG_ERR_NOMEM
) {
2761 *cmd_result
= error_code
;
2765 goto error_free_ht_element
;
2770 * The rest only applies to triggers that have a "notify" action.
2771 * It is not skipped as this is the only action type currently
2774 if (is_trigger_action_notify(trigger
)) {
2776 * Find or create the client list of this condition. It may
2777 * already be present if another trigger is already registered
2778 * with the same condition.
2780 client_list
= get_client_list_from_condition(state
, condition
);
2783 * No client list for this condition yet. We create new
2784 * one and build it up.
2786 client_list
= notification_client_list_create(state
, condition
);
2788 ERR("Error creating notification client list for trigger %s",
2791 goto error_free_ht_element
;
2795 CDS_INIT_LIST_HEAD(&trigger_ht_element
->client_list_trigger_node
);
2797 pthread_mutex_lock(&client_list
->lock
);
2798 cds_list_add(&trigger_ht_element
->client_list_trigger_node
,
2799 &client_list
->triggers_list
);
2800 pthread_mutex_unlock(&client_list
->lock
);
2804 * Ownership of the trigger and of its wrapper was transfered to
2805 * the triggers_ht. Same for token ht element if necessary.
2807 trigger_ht_element
= nullptr;
2808 free_trigger
= false;
2810 switch (get_condition_binding_object(condition
)) {
2811 case LTTNG_OBJECT_TYPE_SESSION
:
2812 /* Add the trigger to the list if it matches a known session. */
2813 ret
= bind_trigger_to_matching_session(trigger
, state
);
2815 goto error_free_ht_element
;
2818 case LTTNG_OBJECT_TYPE_CHANNEL
:
2820 * Add the trigger to list of triggers bound to the channels
2823 ret
= bind_trigger_to_matching_channels(trigger
, state
);
2825 goto error_free_ht_element
;
2828 case LTTNG_OBJECT_TYPE_NONE
:
2831 ERR("Unknown object type on which to bind a newly registered trigger was encountered");
2833 goto error_free_ht_element
;
2837 * The new trigger's condition must be evaluated against the current
2840 * In the case of `notify` action, nothing preventing clients from
2841 * subscribing to a condition before the corresponding trigger is
2842 * registered, we have to evaluate this new condition right away.
2844 * At some point, we were waiting for the next "evaluation" (e.g. on
2845 * reception of a channel sample) to evaluate this new condition, but
2848 * The reason it was broken is that waiting for the next sample
2849 * does not allow us to properly handle transitions for edge-triggered
2852 * Consider this example: when we handle a new channel sample, we
2853 * evaluate each conditions twice: once with the previous state, and
2854 * again with the newest state. We then use those two results to
2855 * determine whether a state change happened: a condition was false and
2856 * became true. If a state change happened, we have to notify clients.
2858 * Now, if a client subscribes to a given notification and registers
2859 * a trigger *after* that subscription, we have to make sure the
2860 * condition is evaluated at this point while considering only the
2861 * current state. Otherwise, the next evaluation cycle may only see
2862 * that the evaluations remain the same (true for samples n-1 and n) and
2863 * the client will never know that the condition has been met.
2865 switch (get_condition_binding_object(condition
)) {
2866 case LTTNG_OBJECT_TYPE_SESSION
:
2868 /* Find the session associated with the condition. */
2869 const auto *session_name
= get_condition_session_name(condition
);
2870 auto session_info
= get_session_info_by_name(state
, session_name
);
2871 if (!session_info
) {
2872 /* Not an error, the session doesn't exist yet. */
2873 DBG("Session not found while evaluating session condition during registration of trigger: session name = `%s`",
2879 LTTNG_OPTIONAL_SET(&object_creds
.uid
, session_info
->uid
);
2880 LTTNG_OPTIONAL_SET(&object_creds
.gid
, session_info
->gid
);
2882 ret
= evaluate_session_condition(condition
, session_info
, nullptr, &evaluation
);
2883 session_info_put(session_info
);
2886 case LTTNG_OBJECT_TYPE_CHANNEL
:
2887 ret
= evaluate_channel_condition_for_client(
2888 condition
, state
, &evaluation
, &object_uid
, &object_gid
);
2889 LTTNG_OPTIONAL_SET(&object_creds
.uid
, object_uid
);
2890 LTTNG_OPTIONAL_SET(&object_creds
.gid
, object_gid
);
2892 case LTTNG_OBJECT_TYPE_NONE
:
2895 case LTTNG_OBJECT_TYPE_UNKNOWN
:
2903 goto error_free_ht_element
;
2906 DBG("Newly registered trigger's condition evaluated to %s", evaluation
? "true" : "false");
2908 /* Evaluation yielded nothing. Normal exit. */
2914 * Ownership of `evaluation` transferred to the action executor
2915 * no matter the result.
2917 executor_status
= action_executor_enqueue_trigger(
2918 state
->executor
, trigger
, evaluation
, &object_creds
, client_list
);
2919 evaluation
= nullptr;
2920 switch (executor_status
) {
2921 case ACTION_EXECUTOR_STATUS_OK
:
2923 case ACTION_EXECUTOR_STATUS_ERROR
:
2924 case ACTION_EXECUTOR_STATUS_INVALID
:
2926 * TODO Add trigger identification (name/id) when
2927 * it is added to the API.
2929 ERR("Fatal error occurred while enqueuing action associated to newly registered trigger");
2931 goto error_free_ht_element
;
2932 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
2934 * TODO Add trigger identification (name/id) when
2935 * it is added to the API.
2937 * Not a fatal error.
2939 WARN("No space left when enqueuing action associated to newly registered trigger");
2947 *cmd_result
= LTTNG_OK
;
2948 DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64
,
2950 trigger_tracer_token
);
2953 error_free_ht_element
:
2954 if (trigger_ht_element
) {
2955 /* Delayed removal due to RCU constraint on delete. */
2956 call_rcu(&trigger_ht_element
->rcu_node
, free_lttng_trigger_ht_element_rcu
);
2961 * Other objects might have a reference to the trigger, mark it
2964 lttng_trigger_set_as_unregistered(trigger
);
2965 lttng_trigger_destroy(trigger
);
2971 static void free_lttng_trigger_ht_element_rcu(struct rcu_head
*node
)
2973 free(caa_container_of(node
, struct lttng_trigger_ht_element
, rcu_node
));
2976 static void free_notification_trigger_tokens_ht_element_rcu(struct rcu_head
*node
)
2978 free(caa_container_of(node
, struct notification_trigger_tokens_ht_element
, rcu_node
));
2981 static void teardown_tracer_notifier(struct notification_thread_state
*state
,
2982 const struct lttng_trigger
*trigger
)
2984 struct cds_lfht_iter iter
;
2985 struct notification_trigger_tokens_ht_element
*trigger_tokens_ht_element
;
2988 lttng::urcu::read_lock_guard read_lock
;
2990 cds_lfht_for_each_entry (
2991 state
->trigger_tokens_ht
, &iter
, trigger_tokens_ht_element
, node
) {
2992 if (!lttng_trigger_is_equal(trigger
, trigger_tokens_ht_element
->trigger
)) {
2996 event_notifier_error_accounting_unregister_event_notifier(
2997 trigger_tokens_ht_element
->trigger
);
2999 /* TODO talk to all app and remove it */
3000 DBG("Removed trigger from tokens_ht");
3001 cds_lfht_del(state
->trigger_tokens_ht
, &trigger_tokens_ht_element
->node
);
3003 call_rcu(&trigger_tokens_ht_element
->rcu_node
,
3004 free_notification_trigger_tokens_ht_element_rcu
);
3012 remove_trigger_from_session_trigger_list(struct lttng_session_trigger_list
*trigger_list
,
3013 const struct lttng_trigger
*trigger
)
3016 struct lttng_trigger_list_element
*trigger_element
, *tmp
;
3018 cds_list_for_each_entry_safe (trigger_element
, tmp
, &trigger_list
->list
, node
) {
3019 if (!lttng_trigger_is_equal(trigger
, trigger_element
->trigger
)) {
3023 DBG("Removed trigger from session_triggers_ht");
3024 cds_list_del(&trigger_element
->node
);
3025 free(trigger_element
);
3026 /* A trigger can only appear once per session. */
3032 ERR("Failed to find trigger associated with session: session name = `%s`",
3033 trigger_list
->session_name
);
3036 LTTNG_ASSERT(found
);
3040 handle_notification_thread_command_unregister_trigger(struct notification_thread_state
*state
,
3041 const struct lttng_trigger
*trigger
,
3042 enum lttng_error_code
*_cmd_reply
)
3044 struct cds_lfht_iter iter
;
3045 struct cds_lfht_node
*triggers_ht_node
;
3046 struct notification_client_list
*client_list
;
3047 struct lttng_trigger_ht_element
*trigger_ht_element
= nullptr;
3048 const struct lttng_condition
*condition
= lttng_trigger_get_const_condition(trigger
);
3049 enum lttng_error_code cmd_reply
;
3051 lttng::urcu::read_lock_guard read_lock
;
3054 state
->triggers_ht
, lttng_condition_hash(condition
), match_trigger
, trigger
, &iter
);
3055 triggers_ht_node
= cds_lfht_iter_get_node(&iter
);
3056 if (!triggers_ht_node
) {
3057 cmd_reply
= LTTNG_ERR_TRIGGER_NOT_FOUND
;
3060 cmd_reply
= LTTNG_OK
;
3063 trigger_ht_element
=
3064 caa_container_of(triggers_ht_node
, struct lttng_trigger_ht_element
, node
);
3066 switch (get_condition_binding_object(condition
)) {
3067 case LTTNG_OBJECT_TYPE_CHANNEL
:
3069 struct lttng_channel_trigger_list
*trigger_list
;
3072 * Remove trigger from channel_triggers_ht.
3074 * Note that multiple channels may have matched the trigger's
3075 * condition (e.g. all instances of a given channel in per-pid buffering
3078 * Iterate on all lists since we don't know the target channels' keys.
3080 cds_lfht_for_each_entry (
3081 state
->channel_triggers_ht
, &iter
, trigger_list
, channel_triggers_ht_node
) {
3082 struct lttng_trigger_list_element
*trigger_element
, *tmp
;
3084 cds_list_for_each_entry_safe (
3085 trigger_element
, tmp
, &trigger_list
->list
, node
) {
3086 if (!lttng_trigger_is_equal(trigger
, trigger_element
->trigger
)) {
3090 DBG("Removed trigger from channel_triggers_ht");
3091 cds_list_del(&trigger_element
->node
);
3092 free(trigger_element
);
3093 /* A trigger can only appear once per channel */
3099 case LTTNG_OBJECT_TYPE_SESSION
:
3102 get_session_info_by_name(state
, get_condition_session_name(condition
));
3104 /* Session doesn't exist, no trigger to remove. */
3109 auto session_trigger_list
= get_session_trigger_list(state
, session
->name
);
3110 remove_trigger_from_session_trigger_list(session_trigger_list
, trigger
);
3111 session_info_put(session
);
3113 case LTTNG_OBJECT_TYPE_NONE
:
3119 if (lttng_trigger_needs_tracer_notifier(trigger
)) {
3120 teardown_tracer_notifier(state
, trigger
);
3123 if (is_trigger_action_notify(trigger
)) {
3125 * Remove and release the client list from
3126 * notification_trigger_clients_ht.
3128 client_list
= get_client_list_from_condition(state
, condition
);
3129 LTTNG_ASSERT(client_list
);
3131 pthread_mutex_lock(&client_list
->lock
);
3132 cds_list_del(&trigger_ht_element
->client_list_trigger_node
);
3133 pthread_mutex_unlock(&client_list
->lock
);
3135 /* Put new reference and the hashtable's reference. */
3136 notification_client_list_put(client_list
);
3137 notification_client_list_put(client_list
);
3138 client_list
= nullptr;
3141 /* Remove trigger from triggers_ht. */
3142 notif_thread_state_remove_trigger_ht_elem(state
, trigger_ht_element
);
3144 /* Release the ownership of the trigger. */
3145 lttng_trigger_destroy(trigger_ht_element
->trigger
);
3146 call_rcu(&trigger_ht_element
->rcu_node
, free_lttng_trigger_ht_element_rcu
);
3149 *_cmd_reply
= cmd_reply
;
3154 static notification_thread_command
*pop_cmd_queue(notification_thread_handle
*handle
)
3156 lttng::pthread::lock_guard
queue_lock(handle
->cmd_queue
.lock
);
3159 const auto read_ret
= lttng_read(handle
->cmd_queue
.event_fd
, &counter
, sizeof(counter
));
3160 if (read_ret
!= sizeof(counter
)) {
3162 LTTNG_THROW_POSIX("Failed to read counter value from event_fd", errno
);
3164 LTTNG_THROW_ERROR(lttng::format(
3165 "Failed to read counter value from event_fd because of a truncated read: ret={}, expected read size={}",
3171 auto command
= cds_list_first_entry(
3172 &handle
->cmd_queue
.list
, struct notification_thread_command
, cmd_list_node
);
3173 cds_list_del(&((command
)->cmd_list_node
));
3177 /* Returns 0 on success, 1 on exit requested, negative value on error. */
3178 int handle_notification_thread_command(struct notification_thread_handle
*handle
,
3179 struct notification_thread_state
*state
)
3182 struct notification_thread_command
*cmd
= nullptr;
3185 cmd
= pop_cmd_queue(handle
);
3186 } catch (const std::exception
& ex
) {
3187 ERR("Failed to get next notification thread command: %s", ex
.what());
3191 DBG("Received `%s` command", notification_command_type_str(cmd
->type
));
3192 switch (cmd
->type
) {
3193 case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER
:
3194 ret
= handle_notification_thread_command_register_trigger(
3196 cmd
->parameters
.register_trigger
.trigger
,
3197 cmd
->parameters
.register_trigger
.is_trigger_anonymous
,
3200 case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER
:
3201 ret
= handle_notification_thread_command_unregister_trigger(
3202 state
, cmd
->parameters
.unregister_trigger
.trigger
, &cmd
->reply_code
);
3204 case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL
:
3205 ret
= handle_notification_thread_command_add_channel(
3207 cmd
->parameters
.add_channel
.session
.id
,
3208 cmd
->parameters
.add_channel
.channel
.name
,
3209 cmd
->parameters
.add_channel
.channel
.domain
,
3210 cmd
->parameters
.add_channel
.channel
.key
,
3211 cmd
->parameters
.add_channel
.channel
.capacity
,
3214 case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL
:
3215 ret
= handle_notification_thread_command_remove_channel(
3217 cmd
->parameters
.remove_channel
.key
,
3218 cmd
->parameters
.remove_channel
.domain
,
3221 case NOTIFICATION_COMMAND_TYPE_ADD_SESSION
:
3222 ret
= handle_notification_thread_command_add_session(
3224 cmd
->parameters
.add_session
.session_id
,
3225 cmd
->parameters
.add_session
.session_name
,
3226 cmd
->parameters
.add_session
.session_uid
,
3227 cmd
->parameters
.add_session
.session_gid
,
3230 case NOTIFICATION_COMMAND_TYPE_REMOVE_SESSION
:
3231 ret
= handle_notification_thread_command_remove_session(
3232 state
, cmd
->parameters
.remove_session
.session_id
, &cmd
->reply_code
);
3234 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_ONGOING
:
3235 case NOTIFICATION_COMMAND_TYPE_SESSION_ROTATION_COMPLETED
:
3236 ret
= handle_notification_thread_command_session_rotation(
3239 cmd
->parameters
.session_rotation
.session_id
,
3240 cmd
->parameters
.session_rotation
.trace_archive_chunk_id
,
3241 cmd
->parameters
.session_rotation
.location
,
3244 case NOTIFICATION_COMMAND_TYPE_ADD_TRACER_EVENT_SOURCE
:
3245 ret
= handle_notification_thread_command_add_tracer_event_source(
3247 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3248 cmd
->parameters
.tracer_event_source
.domain
,
3251 case NOTIFICATION_COMMAND_TYPE_REMOVE_TRACER_EVENT_SOURCE
:
3252 ret
= handle_notification_thread_command_remove_tracer_event_source(
3254 cmd
->parameters
.tracer_event_source
.tracer_event_source_fd
,
3257 case NOTIFICATION_COMMAND_TYPE_LIST_TRIGGERS
:
3259 struct lttng_triggers
*triggers
= nullptr;
3261 ret
= handle_notification_thread_command_list_triggers(
3264 cmd
->parameters
.list_triggers
.uid
,
3267 cmd
->reply
.list_triggers
.triggers
= triggers
;
3271 case NOTIFICATION_COMMAND_TYPE_QUIT
:
3272 cmd
->reply_code
= LTTNG_OK
;
3275 case NOTIFICATION_COMMAND_TYPE_GET_TRIGGER
:
3277 struct lttng_trigger
*trigger
= nullptr;
3279 ret
= handle_notification_thread_command_get_trigger(
3280 state
, cmd
->parameters
.get_trigger
.trigger
, &trigger
, &cmd
->reply_code
);
3281 cmd
->reply
.get_trigger
.trigger
= trigger
;
3284 case NOTIFICATION_COMMAND_TYPE_CLIENT_COMMUNICATION_UPDATE
:
3286 const enum client_transmission_status client_status
=
3287 cmd
->parameters
.client_communication_update
.status
;
3288 const notification_client_id client_id
=
3289 cmd
->parameters
.client_communication_update
.id
;
3290 struct notification_client
*client
;
3292 lttng::urcu::read_lock_guard read_lock
;
3293 client
= get_client_from_id(client_id
, state
);
3297 * Client error was probably already picked-up by the
3298 * notification thread or it has disconnected
3299 * gracefully while this command was queued.
3301 DBG("Failed to find notification client to update communication status, client id = %" PRIu64
,
3305 ret
= client_handle_transmission_status(client
, client_status
, state
);
3310 ERR("Unknown internal command received");
3320 if (cmd
->is_async
) {
3324 cmd
->command_completed_waker
->wake();
3331 /* Wake-up and return a fatal error to the calling thread. */
3332 cmd
->reply_code
= LTTNG_ERR_FATAL
;
3339 static int socket_set_non_blocking(int socket
)
3343 /* Set the pipe as non-blocking. */
3344 ret
= fcntl(socket
, F_GETFL
, 0);
3346 PERROR("fcntl get socket flags");
3351 ret
= fcntl(socket
, F_SETFL
, flags
| O_NONBLOCK
);
3353 PERROR("fcntl set O_NONBLOCK socket flag");
3356 DBG("Client socket (fd = %i) set as non-blocking", socket
);
3361 static int client_reset_inbound_state(struct notification_client
*client
)
3365 lttng_payload_clear(&client
->communication
.inbound
.payload
);
3367 client
->communication
.inbound
.bytes_to_receive
=
3368 sizeof(struct lttng_notification_channel_message
);
3369 client
->communication
.inbound
.msg_type
= LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
;
3370 LTTNG_SOCK_SET_UID_CRED(&client
->communication
.inbound
.creds
, -1);
3371 LTTNG_SOCK_SET_GID_CRED(&client
->communication
.inbound
.creds
, -1);
3372 ret
= lttng_dynamic_buffer_set_size(&client
->communication
.inbound
.payload
.buffer
,
3373 client
->communication
.inbound
.bytes_to_receive
);
3378 int handle_notification_thread_client_connect(struct notification_thread_state
*state
)
3381 struct notification_client
*client
;
3383 DBG("Handling new notification channel client connection");
3385 client
= zmalloc
<notification_client
>();
3392 pthread_mutex_init(&client
->lock
, nullptr);
3393 client
->id
= state
->next_notification_client_id
++;
3394 CDS_INIT_LIST_HEAD(&client
->condition_list
);
3395 lttng_payload_init(&client
->communication
.inbound
.payload
);
3396 lttng_payload_init(&client
->communication
.outbound
.payload
);
3397 client
->communication
.inbound
.expect_creds
= true;
3399 ret
= client_reset_inbound_state(client
);
3401 ERR("Failed to reset client communication's inbound state");
3406 ret
= lttcomm_accept_unix_sock(state
->notification_channel_socket
);
3408 ERR("Failed to accept new notification channel client connection");
3413 client
->socket
= ret
;
3415 ret
= socket_set_non_blocking(client
->socket
);
3417 ERR("Failed to set new notification channel client connection socket as non-blocking");
3421 ret
= lttcomm_setsockopt_creds_unix_sock(client
->socket
);
3423 ERR("Failed to set socket options on new notification channel client socket");
3428 client
->communication
.current_poll_events
= CLIENT_POLL_EVENTS_IN
;
3429 ret
= lttng_poll_add(
3430 &state
->events
, client
->socket
, client
->communication
.current_poll_events
);
3432 ERR("Failed to add notification channel client socket to poll set");
3436 DBG("Added new notification channel client socket (%i) to poll set", client
->socket
);
3439 lttng::urcu::read_lock_guard read_lock
;
3441 cds_lfht_add(state
->client_socket_ht
,
3442 hash_client_socket(client
->socket
),
3443 &client
->client_socket_ht_node
);
3444 cds_lfht_add(state
->client_id_ht
,
3445 hash_client_id(client
->id
),
3446 &client
->client_id_ht_node
);
3452 notification_client_destroy(client
);
3457 * RCU read-lock must be held by the caller.
3458 * Client lock must _not_ be held by the caller.
3460 static int notification_thread_client_disconnect(struct notification_client
*client
,
3461 struct notification_thread_state
*state
)
3464 struct lttng_condition_list_element
*condition_list_element
, *tmp
;
3466 ASSERT_RCU_READ_LOCKED();
3468 /* Acquire the client lock to disable its communication atomically. */
3469 pthread_mutex_lock(&client
->lock
);
3470 client
->communication
.active
= false;
3471 cds_lfht_del(state
->client_socket_ht
, &client
->client_socket_ht_node
);
3472 cds_lfht_del(state
->client_id_ht
, &client
->client_id_ht_node
);
3473 pthread_mutex_unlock(&client
->lock
);
3475 ret
= lttng_poll_del(&state
->events
, client
->socket
);
3477 ERR("Failed to remove client socket %d from poll set", client
->socket
);
3480 /* Release all conditions to which the client was subscribed. */
3481 cds_list_for_each_entry_safe (condition_list_element
, tmp
, &client
->condition_list
, node
) {
3482 (void) notification_thread_client_unsubscribe(
3483 client
, condition_list_element
->condition
, state
, nullptr);
3487 * Client no longer accessible to other threads (through the
3490 notification_client_destroy(client
);
3494 int handle_notification_thread_client_disconnect(int client_socket
,
3495 struct notification_thread_state
*state
)
3498 struct notification_client
*client
;
3500 lttng::urcu::read_lock_guard read_lock
;
3502 DBG("Closing client connection (socket fd = %i)", client_socket
);
3503 client
= get_client_from_socket(client_socket
, state
);
3505 /* Internal state corruption, fatal error. */
3506 ERR("Unable to find client (socket fd = %i)", client_socket
);
3511 ret
= notification_thread_client_disconnect(client
, state
);
3516 int handle_notification_thread_client_disconnect_all(struct notification_thread_state
*state
)
3518 struct cds_lfht_iter iter
;
3519 struct notification_client
*client
;
3520 bool error_encoutered
= false;
3522 DBG("Closing all client connections");
3525 lttng::urcu::read_lock_guard read_lock
;
3527 cds_lfht_for_each_entry (
3528 state
->client_socket_ht
, &iter
, client
, client_socket_ht_node
) {
3531 ret
= notification_thread_client_disconnect(client
, state
);
3533 error_encoutered
= true;
3538 return error_encoutered
? 1 : 0;
3541 int handle_notification_thread_trigger_unregister_all(struct notification_thread_state
*state
)
3543 bool error_occurred
= false;
3544 struct cds_lfht_iter iter
;
3545 struct lttng_trigger_ht_element
*trigger_ht_element
;
3547 lttng::urcu::read_lock_guard read_lock
;
3548 cds_lfht_for_each_entry (state
->triggers_ht
, &iter
, trigger_ht_element
, node
) {
3549 int ret
= handle_notification_thread_command_unregister_trigger(
3550 state
, trigger_ht_element
->trigger
, nullptr);
3552 error_occurred
= true;
3555 return error_occurred
? -1 : 0;
3558 static bool client_has_outbound_data_left(const struct notification_client
*client
)
3560 const struct lttng_payload_view pv
=
3561 lttng_payload_view_from_payload(&client
->communication
.outbound
.payload
, 0, -1);
3562 const bool has_data
= pv
.buffer
.size
!= 0;
3563 const bool has_fds
= lttng_payload_view_get_fd_handle_count(&pv
);
3565 return has_data
|| has_fds
;
3568 static int client_handle_transmission_status(struct notification_client
*client
,
3569 enum client_transmission_status transmission_status
,
3570 struct notification_thread_state
*state
)
3574 switch (transmission_status
) {
3575 case CLIENT_TRANSMISSION_STATUS_COMPLETE
:
3576 case CLIENT_TRANSMISSION_STATUS_QUEUED
:
3578 int current_poll_events
;
3579 int new_poll_events
;
3581 * We want to be notified whenever there is buffer space
3582 * available to send the rest of the payload if we are
3583 * waiting to send data to the client.
3585 * The state of the outbound queue being sampled here is
3587 * - it is okay to wake-up "for nothing" in case we see
3588 * that data is left, but another thread succeeds in
3589 * flushing it before us when handling the client "out"
3590 * event. We will simply stop monitoring that event the next
3591 * time it wakes us up and we see no data left to be sent,
3592 * - if another thread fails to flush the entire client
3593 * outgoing queue, it will issue a "communication update"
3594 * command and cause the client's (e)poll mask to be
3597 * The situation we seek to avoid would be to disable the
3598 * monitoring of "out" client events indefinitely when there is
3599 * data to be sent, which can't happen because of the
3600 * aforementioned "communication update" mechanism.
3602 pthread_mutex_lock(&client
->lock
);
3603 current_poll_events
= client
->communication
.current_poll_events
;
3604 new_poll_events
= client_has_outbound_data_left(client
) ?
3605 CLIENT_POLL_EVENTS_IN_OUT
:
3606 CLIENT_POLL_EVENTS_IN
;
3607 client
->communication
.current_poll_events
= new_poll_events
;
3608 pthread_mutex_unlock(&client
->lock
);
3610 /* Update the monitored event set only if it changed. */
3611 if (current_poll_events
!= new_poll_events
) {
3612 ret
= lttng_poll_mod(&state
->events
, client
->socket
, new_poll_events
);
3620 case CLIENT_TRANSMISSION_STATUS_FAIL
:
3621 ret
= notification_thread_client_disconnect(client
, state
);
3626 case CLIENT_TRANSMISSION_STATUS_ERROR
:
3636 /* Client lock must be acquired by caller. */
3637 static enum client_transmission_status
3638 client_flush_outgoing_queue(struct notification_client
*client
)
3641 size_t to_send_count
;
3642 enum client_transmission_status status
;
3643 struct lttng_payload_view pv
=
3644 lttng_payload_view_from_payload(&client
->communication
.outbound
.payload
, 0, -1);
3645 const int fds_to_send_count
= lttng_payload_view_get_fd_handle_count(&pv
);
3647 ASSERT_LOCKED(client
->lock
);
3649 if (!client
->communication
.active
) {
3650 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3654 if (pv
.buffer
.size
== 0) {
3656 * If both data and fds are equal to zero, we are in an invalid
3659 LTTNG_ASSERT(fds_to_send_count
!= 0);
3664 to_send_count
= pv
.buffer
.size
;
3665 DBG("Flushing client (socket fd = %i) outgoing queue", client
->socket
);
3667 ret
= lttcomm_send_unix_sock_non_block(client
->socket
, pv
.buffer
.data
, to_send_count
);
3668 if ((ret
>= 0 && ret
< to_send_count
)) {
3669 DBG("Client (socket fd = %i) outgoing queue could not be completely flushed",
3671 to_send_count
-= std::max(ret
, (ssize_t
) 0);
3673 memmove(client
->communication
.outbound
.payload
.buffer
.data
,
3674 pv
.buffer
.data
+ pv
.buffer
.size
- to_send_count
,
3676 ret
= lttng_dynamic_buffer_set_size(&client
->communication
.outbound
.payload
.buffer
,
3682 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3684 } else if (ret
< 0) {
3685 /* Generic error, disable the client's communication. */
3686 ERR("Failed to flush outgoing queue, disconnecting client (socket fd = %i)",
3688 client
->communication
.active
= false;
3689 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3693 * No error and flushed the queue completely.
3695 * The payload buffer size is used later to
3696 * check if there is notifications queued. So albeit that the
3697 * direct caller knows that the transmission is complete, we
3698 * need to set the buffer size to zero.
3700 ret
= lttng_dynamic_buffer_set_size(&client
->communication
.outbound
.payload
.buffer
,
3708 /* No fds to send, transmission is complete. */
3709 if (fds_to_send_count
== 0) {
3710 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3714 ret
= lttcomm_send_payload_view_fds_unix_sock_non_block(client
->socket
, &pv
);
3716 /* Generic error, disable the client's communication. */
3717 ERR("Failed to flush outgoing fds queue, disconnecting client (socket fd = %i)",
3719 client
->communication
.active
= false;
3720 status
= CLIENT_TRANSMISSION_STATUS_FAIL
;
3722 } else if (ret
== 0) {
3723 /* Nothing could be sent. */
3724 status
= CLIENT_TRANSMISSION_STATUS_QUEUED
;
3726 /* Fd passing is an all or nothing kind of thing. */
3727 status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
3729 * The payload _fd_array count is used later to
3730 * check if there is notifications queued. So although the
3731 * direct caller knows that the transmission is complete, we
3732 * need to clear the _fd_array for the queuing check.
3734 lttng_dynamic_pointer_array_clear(
3735 &client
->communication
.outbound
.payload
._fd_handles
);
3739 if (status
== CLIENT_TRANSMISSION_STATUS_COMPLETE
) {
3740 client
->communication
.outbound
.queued_command_reply
= false;
3741 client
->communication
.outbound
.dropped_notification
= false;
3742 lttng_payload_clear(&client
->communication
.outbound
.payload
);
3747 return CLIENT_TRANSMISSION_STATUS_ERROR
;
3750 /* Client lock must _not_ be held by the caller. */
3751 static int client_send_command_reply(struct notification_client
*client
,
3752 struct notification_thread_state
*state
,
3753 enum lttng_notification_channel_status status
)
3756 struct lttng_notification_channel_command_reply reply
= {
3757 .status
= (int8_t) status
,
3759 struct lttng_notification_channel_message msg
;
3760 char buffer
[sizeof(msg
) + sizeof(reply
)];
3761 enum client_transmission_status transmission_status
;
3763 msg
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY
;
3764 msg
.size
= sizeof(reply
);
3767 memcpy(buffer
, &msg
, sizeof(msg
));
3768 memcpy(buffer
+ sizeof(msg
), &reply
, sizeof(reply
));
3769 DBG("Send command reply (%i)", (int) status
);
3771 pthread_mutex_lock(&client
->lock
);
3772 if (client
->communication
.outbound
.queued_command_reply
) {
3773 /* Protocol error. */
3777 /* Enqueue buffer to outgoing queue and flush it. */
3778 ret
= lttng_dynamic_buffer_append(
3779 &client
->communication
.outbound
.payload
.buffer
, buffer
, sizeof(buffer
));
3784 transmission_status
= client_flush_outgoing_queue(client
);
3786 if (client_has_outbound_data_left(client
)) {
3787 /* Queue could not be emptied. */
3788 client
->communication
.outbound
.queued_command_reply
= true;
3791 pthread_mutex_unlock(&client
->lock
);
3792 ret
= client_handle_transmission_status(client
, transmission_status
, state
);
3799 pthread_mutex_unlock(&client
->lock
);
3804 static int client_handle_message_unknown(struct notification_client
*client
,
3805 struct notification_thread_state
*state
3806 __attribute__((unused
)))
3810 * Receiving message header. The function will be called again
3811 * once the rest of the message as been received and can be
3814 const struct lttng_notification_channel_message
*msg
;
3816 LTTNG_ASSERT(sizeof(*msg
) == client
->communication
.inbound
.payload
.buffer
.size
);
3817 msg
= (const struct lttng_notification_channel_message
*)
3818 client
->communication
.inbound
.payload
.buffer
.data
;
3820 if (msg
->size
== 0 || msg
->size
> DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE
) {
3821 ERR("Invalid notification channel message: length = %u", msg
->size
);
3826 switch (msg
->type
) {
3827 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
3828 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
3829 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
3833 ERR("Invalid notification channel message: unexpected message type");
3837 client
->communication
.inbound
.bytes_to_receive
= msg
->size
;
3838 client
->communication
.inbound
.fds_to_receive
= msg
->fds
;
3839 client
->communication
.inbound
.msg_type
=
3840 (enum lttng_notification_channel_message_type
) msg
->type
;
3841 ret
= lttng_dynamic_buffer_set_size(&client
->communication
.inbound
.payload
.buffer
,
3844 /* msg is not valid anymore due to lttng_dynamic_buffer_set_size. */
3850 static int client_handle_message_handshake(struct notification_client
*client
,
3851 struct notification_thread_state
*state
)
3854 struct lttng_notification_channel_command_handshake
*handshake_client
;
3855 const struct lttng_notification_channel_command_handshake handshake_reply
= {
3856 .major
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
,
3857 .minor
= LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR
,
3859 struct lttng_notification_channel_message msg_header
;
3860 enum lttng_notification_channel_status status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
3861 char send_buffer
[sizeof(msg_header
) + sizeof(handshake_reply
)];
3863 msg_header
.type
= LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
;
3864 msg_header
.size
= sizeof(handshake_reply
);
3867 memcpy(send_buffer
, &msg_header
, sizeof(msg_header
));
3868 memcpy(send_buffer
+ sizeof(msg_header
), &handshake_reply
, sizeof(handshake_reply
));
3870 handshake_client
= (struct lttng_notification_channel_command_handshake
*)
3871 client
->communication
.inbound
.payload
.buffer
.data
;
3872 client
->major
= handshake_client
->major
;
3873 client
->minor
= handshake_client
->minor
;
3874 if (!client
->communication
.inbound
.creds_received
) {
3875 ERR("No credentials received from client");
3880 client
->uid
= LTTNG_SOCK_GET_UID_CRED(&client
->communication
.inbound
.creds
);
3881 client
->gid
= LTTNG_SOCK_GET_GID_CRED(&client
->communication
.inbound
.creds
);
3882 client
->is_sessiond
= LTTNG_SOCK_GET_PID_CRED(&client
->communication
.inbound
.creds
) ==
3884 DBG("Received handshake from client: uid = %u, gid = %u, protocol version = %i.%i, client is sessiond = %s",
3887 (int) client
->major
,
3888 (int) client
->minor
,
3889 client
->is_sessiond
? "true" : "false");
3891 if (handshake_client
->major
!= LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR
) {
3892 status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION
;
3895 pthread_mutex_lock(&client
->lock
);
3896 /* Outgoing queue will be flushed when the command reply is sent. */
3897 ret
= lttng_dynamic_buffer_append(
3898 &client
->communication
.outbound
.payload
.buffer
, send_buffer
, sizeof(send_buffer
));
3900 ERR("Failed to send protocol version to notification channel client");
3904 client
->validated
= true;
3905 client
->communication
.active
= true;
3906 pthread_mutex_unlock(&client
->lock
);
3908 /* Set reception state to receive the next message header. */
3909 ret
= client_reset_inbound_state(client
);
3911 ERR("Failed to reset client communication's inbound state");
3915 /* Flushes the outgoing queue. */
3916 ret
= client_send_command_reply(client
, state
, status
);
3918 ERR("Failed to send reply to notification channel client");
3924 pthread_mutex_unlock(&client
->lock
);
3929 static int client_handle_message_subscription(struct notification_client
*client
,
3930 enum lttng_notification_channel_message_type msg_type
,
3931 struct notification_thread_state
*state
)
3934 struct lttng_condition
*condition
;
3935 enum lttng_notification_channel_status status
= LTTNG_NOTIFICATION_CHANNEL_STATUS_OK
;
3936 struct lttng_payload_view condition_view
=
3937 lttng_payload_view_from_payload(&client
->communication
.inbound
.payload
, 0, -1);
3938 size_t expected_condition_size
;
3941 * No need to lock client to sample the inbound state as the only
3942 * other thread accessing clients (action executor) only uses the
3945 expected_condition_size
= client
->communication
.inbound
.payload
.buffer
.size
;
3946 ret
= lttng_condition_create_from_payload(&condition_view
, &condition
);
3947 if (ret
!= expected_condition_size
) {
3948 ERR("Malformed condition received from client");
3952 /* Ownership of condition is always transferred. */
3953 if (msg_type
== LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
) {
3954 ret
= notification_thread_client_subscribe(client
, condition
, state
, &status
);
3956 ret
= notification_thread_client_unsubscribe(client
, condition
, state
, &status
);
3963 /* Set reception state to receive the next message header. */
3964 ret
= client_reset_inbound_state(client
);
3966 ERR("Failed to reset client communication's inbound state");
3970 ret
= client_send_command_reply(client
, state
, status
);
3972 ERR("Failed to send reply to notification channel client");
3980 static int client_dispatch_message(struct notification_client
*client
,
3981 struct notification_thread_state
*state
)
3985 if (client
->communication
.inbound
.msg_type
!=
3986 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
&&
3987 client
->communication
.inbound
.msg_type
!=
3988 LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
&&
3989 !client
->validated
) {
3990 WARN("client attempted a command before handshake");
3995 switch (client
->communication
.inbound
.msg_type
) {
3996 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN
:
3998 ret
= client_handle_message_unknown(client
, state
);
4001 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE
:
4003 ret
= client_handle_message_handshake(client
, state
);
4006 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE
:
4007 case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE
:
4009 ret
= client_handle_message_subscription(
4010 client
, client
->communication
.inbound
.msg_type
, state
);
4020 /* Incoming data from client. */
4021 int handle_notification_thread_client_in(struct notification_thread_state
*state
, int socket
)
4024 struct notification_client
*client
;
4028 lttng::urcu::read_lock_guard read_lock
;
4029 client
= get_client_from_socket(socket
, state
);
4031 /* Internal error, abort. */
4036 if (client
->communication
.inbound
.bytes_to_receive
== 0 &&
4037 client
->communication
.inbound
.fds_to_receive
!= 0) {
4038 /* Only FDs left to receive. */
4042 offset
= client
->communication
.inbound
.payload
.buffer
.size
-
4043 client
->communication
.inbound
.bytes_to_receive
;
4044 if (client
->communication
.inbound
.expect_creds
) {
4045 recv_ret
= lttcomm_recv_creds_unix_sock(
4047 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4048 client
->communication
.inbound
.bytes_to_receive
,
4049 &client
->communication
.inbound
.creds
);
4051 client
->communication
.inbound
.expect_creds
= false;
4052 client
->communication
.inbound
.creds_received
= true;
4055 recv_ret
= lttcomm_recv_unix_sock_non_block(
4057 client
->communication
.inbound
.payload
.buffer
.data
+ offset
,
4058 client
->communication
.inbound
.bytes_to_receive
);
4060 if (recv_ret
>= 0) {
4061 client
->communication
.inbound
.bytes_to_receive
-= recv_ret
;
4063 goto error_disconnect_client
;
4066 if (client
->communication
.inbound
.bytes_to_receive
!= 0) {
4067 /* Message incomplete wait for more data. */
4073 LTTNG_ASSERT(client
->communication
.inbound
.bytes_to_receive
== 0);
4076 if (client
->communication
.inbound
.fds_to_receive
!= 0) {
4077 ret
= lttcomm_recv_payload_fds_unix_sock_non_block(
4079 client
->communication
.inbound
.fds_to_receive
,
4080 &client
->communication
.inbound
.payload
);
4083 * Fds received. non blocking fds passing is all
4086 ssize_t expected_size
;
4088 expected_size
= sizeof(int) * client
->communication
.inbound
.fds_to_receive
;
4089 LTTNG_ASSERT(ret
== expected_size
);
4090 client
->communication
.inbound
.fds_to_receive
= 0;
4091 } else if (ret
== 0) {
4092 /* Received nothing. */
4096 goto error_disconnect_client
;
4100 /* At this point the message is complete.*/
4101 LTTNG_ASSERT(client
->communication
.inbound
.bytes_to_receive
== 0 &&
4102 client
->communication
.inbound
.fds_to_receive
== 0);
4103 ret
= client_dispatch_message(client
, state
);
4106 * Only returns an error if this client must be
4109 goto error_disconnect_client
;
4115 error_disconnect_client
:
4116 ret
= notification_thread_client_disconnect(client
, state
);
4120 /* Client ready to receive outgoing data. */
4121 int handle_notification_thread_client_out(struct notification_thread_state
*state
, int socket
)
4124 struct notification_client
*client
;
4125 enum client_transmission_status transmission_status
;
4127 lttng::urcu::read_lock_guard read_lock
;
4128 client
= get_client_from_socket(socket
, state
);
4130 /* Internal error, abort. */
4135 pthread_mutex_lock(&client
->lock
);
4136 if (!client_has_outbound_data_left(client
)) {
4138 * A client "out" event can be received when no payload is left
4139 * to send under some circumstances.
4141 * Many threads can flush a client's outgoing queue and, if they
4142 * had to queue their message (socket was full), will use the
4143 * "communication update" command to signal the (e)poll thread
4144 * to monitor for space being made available in the socket.
4146 * Commands are sent over an internal pipe serviced by the same
4147 * thread as the client sockets.
4149 * When space is made available in the socket, there is a race
4150 * between the (e)poll thread and the other threads that may
4151 * wish to use the client's socket to flush its outgoing queue.
4153 * A non-(e)poll thread may attempt (and succeed) in flushing
4154 * the queue before the (e)poll thread gets a chance to service
4155 * the client's "out" event.
4157 * In this situation, the (e)poll thread processing the client
4158 * out event will see an empty payload: there is nothing to do
4159 * except unsubscribing (e)poll "out" events.
4161 * Note that this thread is the (e)poll thread so it can modify
4162 * the (e)poll mask directly without using a communication
4163 * update command. Other threads that flush the outgoing queue
4164 * will use the "communication update" command to wake up this
4165 * thread and force it to monitor "out" events.
4167 * When other threads succeed in emptying the outgoing queue,
4168 * they don't need to update the (e)poll mask: if the "out"
4169 * event is monitored, it will fire once and the (e)poll
4170 * thread will reach this condition, causing the event to
4171 * stop being monitored.
4173 transmission_status
= CLIENT_TRANSMISSION_STATUS_COMPLETE
;
4175 transmission_status
= client_flush_outgoing_queue(client
);
4177 pthread_mutex_unlock(&client
->lock
);
4179 ret
= client_handle_transmission_status(client
, transmission_status
, state
);
4187 static bool evaluate_buffer_usage_condition(const struct lttng_condition
*condition
,
4188 const struct channel_state_sample
*sample
,
4189 uint64_t buffer_capacity
)
4191 bool result
= false;
4193 enum lttng_condition_type condition_type
;
4194 const struct lttng_condition_buffer_usage
*use_condition
=
4195 lttng::utils::container_of(condition
, <tng_condition_buffer_usage::parent
);
4197 if (use_condition
->threshold_bytes
.set
) {
4198 threshold
= use_condition
->threshold_bytes
.value
;
4201 * Threshold was expressed as a ratio.
4203 * TODO the threshold (in bytes) of conditions expressed
4204 * as a ratio of total buffer size could be cached to
4205 * forego this double-multiplication or it could be performed
4206 * as fixed-point math.
4208 * Note that caching should accommodates the case where the
4209 * condition applies to multiple channels (i.e. don't assume
4210 * that all channels matching my_chann* have the same size...)
4212 threshold
= (uint64_t) (use_condition
->threshold_ratio
.value
*
4213 (double) buffer_capacity
);
4216 condition_type
= lttng_condition_get_type(condition
);
4217 if (condition_type
== LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
) {
4218 DBG("Low buffer usage condition being evaluated: threshold = %" PRIu64
4219 ", highest usage = %" PRIu64
,
4221 sample
->highest_usage
);
4224 * The low condition should only be triggered once _all_ of the
4225 * streams in a channel have gone below the "low" threshold.
4227 if (sample
->highest_usage
<= threshold
) {
4231 DBG("High buffer usage condition being evaluated: threshold = %" PRIu64
4232 ", highest usage = %" PRIu64
,
4234 sample
->highest_usage
);
4237 * For high buffer usage scenarios, we want to trigger whenever
4238 * _any_ of the streams has reached the "high" threshold.
4240 if (sample
->highest_usage
>= threshold
) {
4248 static int evaluate_buffer_condition(const struct lttng_condition
*condition
,
4249 struct lttng_evaluation
**evaluation
,
4250 const struct notification_thread_state
*state
4251 __attribute__((unused
)),
4252 const struct channel_state_sample
*previous_sample
,
4253 const struct channel_state_sample
*latest_sample
,
4254 struct channel_info
*channel_info
)
4257 enum lttng_condition_type condition_type
;
4258 const bool previous_sample_available
= !!previous_sample
;
4259 bool previous_sample_result
= false;
4260 bool latest_sample_result
;
4262 condition_type
= lttng_condition_get_type(condition
);
4264 switch (condition_type
) {
4265 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4266 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4267 if (caa_likely(previous_sample_available
)) {
4268 previous_sample_result
= evaluate_buffer_usage_condition(
4269 condition
, previous_sample
, channel_info
->capacity
);
4271 latest_sample_result
= evaluate_buffer_usage_condition(
4272 condition
, latest_sample
, channel_info
->capacity
);
4275 /* Unknown condition type; internal error. */
4279 if (!latest_sample_result
|| (previous_sample_result
== latest_sample_result
)) {
4281 * Only trigger on a condition evaluation transition.
4283 * NOTE: This edge-triggered logic may not be appropriate for
4284 * future condition types.
4289 if (!evaluation
|| !latest_sample_result
) {
4293 switch (condition_type
) {
4294 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW
:
4295 case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH
:
4296 *evaluation
= lttng_evaluation_buffer_usage_create(
4297 condition_type
, latest_sample
->highest_usage
, channel_info
->capacity
);
4311 static int client_notification_overflow(struct notification_client
*client
)
4314 struct lttng_notification_channel_message msg
;
4316 msg
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED
;
4320 ASSERT_LOCKED(client
->lock
);
4322 DBG("Dropping notification addressed to client (socket fd = %i)", client
->socket
);
4323 if (client
->communication
.outbound
.dropped_notification
) {
4325 * The client already has a "notification dropped" message
4326 * in its outgoing queue. Nothing to do since all
4327 * of those messages are coalesced.
4332 client
->communication
.outbound
.dropped_notification
= true;
4333 ret
= lttng_dynamic_buffer_append(
4334 &client
->communication
.outbound
.payload
.buffer
, &msg
, sizeof(msg
));
4336 PERROR("Failed to enqueue \"dropped notification\" message in client's (socket fd = %i) outgoing queue",
4343 static int client_handle_transmission_status_wrapper(struct notification_client
*client
,
4344 enum client_transmission_status status
,
4347 return client_handle_transmission_status(
4348 client
, status
, (struct notification_thread_state
*) user_data
);
4351 static int send_evaluation_to_clients(const struct lttng_trigger
*trigger
,
4352 const struct lttng_evaluation
*evaluation
,
4353 struct notification_client_list
*client_list
,
4354 struct notification_thread_state
*state
,
4358 const struct lttng_credentials creds
= {
4359 .uid
= LTTNG_OPTIONAL_INIT_VALUE(object_uid
),
4360 .gid
= LTTNG_OPTIONAL_INIT_VALUE(object_gid
),
4363 return notification_client_list_send_evaluation(client_list
,
4367 client_handle_transmission_status_wrapper
,
4372 * Permission checks relative to notification channel clients are performed
4373 * here. Notice how object, client, and trigger credentials are involved in
4376 * The `object` credentials are the credentials associated with the "subject"
4377 * of a condition. For instance, a `rotation completed` condition applies
4378 * to a session. When that condition is met, it will produce an evaluation
4379 * against a session. Hence, in this case, the `object` credentials are the
4380 * credentials of the "subject" session.
4382 * The `trigger` credentials are the credentials of the user that registered the
4385 * The `client` credentials are the credentials of the user that created a given
4386 * notification channel.
4388 * In terms of visibility, it is expected that non-privilieged users can only
4389 * register triggers against "their" objects (their own sessions and
4390 * applications they are allowed to interact with). They can then open a
4391 * notification channel and subscribe to notifications associated with those
4394 * As for privilieged users, they can register triggers against the objects of
4395 * other users. They can then subscribe to the notifications associated to their
4396 * triggers. Privilieged users _can't_ subscribe to the notifications of
4397 * triggers owned by other users; they must create their own triggers.
4399 * This is more a concern of usability than security. It would be difficult for
4400 * a root user reliably subscribe to a specific set of conditions without
4401 * interference from external users (those could, for instance, unregister
4404 int notification_client_list_send_evaluation(struct notification_client_list
*client_list
,
4405 const struct lttng_trigger
*trigger
,
4406 const struct lttng_evaluation
*evaluation
,
4407 const struct lttng_credentials
*source_object_creds
,
4408 report_client_transmission_result_cb client_report
,
4412 struct lttng_payload msg_payload
;
4413 struct notification_client_list_element
*client_list_element
, *tmp
;
4414 const struct lttng_notification notification
= {
4415 .trigger
= (struct lttng_trigger
*) trigger
,
4416 .evaluation
= (struct lttng_evaluation
*) evaluation
,
4418 struct lttng_notification_channel_message msg_header
;
4419 const struct lttng_credentials
*trigger_creds
= lttng_trigger_get_credentials(trigger
);
4421 lttng_payload_init(&msg_payload
);
4423 msg_header
.type
= (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION
;
4424 msg_header
.size
= 0;
4427 ret
= lttng_dynamic_buffer_append(&msg_payload
.buffer
, &msg_header
, sizeof(msg_header
));
4432 ret
= lttng_notification_serialize(¬ification
, &msg_payload
);
4434 ERR("Failed to serialize notification");
4439 /* Update payload size. */
4440 ((struct lttng_notification_channel_message
*) msg_payload
.buffer
.data
)->size
=
4441 (uint32_t) (msg_payload
.buffer
.size
- sizeof(msg_header
));
4443 /* Update the payload number of fds. */
4445 const struct lttng_payload_view pv
=
4446 lttng_payload_view_from_payload(&msg_payload
, 0, -1);
4448 ((struct lttng_notification_channel_message
*) msg_payload
.buffer
.data
)->fds
=
4449 (uint32_t) lttng_payload_view_get_fd_handle_count(&pv
);
4452 pthread_mutex_lock(&client_list
->lock
);
4453 cds_list_for_each_entry_safe (client_list_element
, tmp
, &client_list
->clients_list
, node
) {
4454 enum client_transmission_status transmission_status
;
4455 struct notification_client
*client
= client_list_element
->client
;
4458 pthread_mutex_lock(&client
->lock
);
4459 if (!client
->communication
.active
) {
4461 * Skip inactive client (protocol error or
4464 DBG("Skipping client at it is marked as inactive");
4468 if (lttng_trigger_is_hidden(trigger
) && !client
->is_sessiond
) {
4470 * Notifications resulting from an hidden trigger are
4471 * only sent to the session daemon.
4473 DBG("Skipping client as the trigger is hidden and the client is not the session daemon");
4477 if (source_object_creds
) {
4478 if (client
->uid
!= lttng_credentials_get_uid(source_object_creds
) &&
4479 client
->gid
!= lttng_credentials_get_gid(source_object_creds
) &&
4482 * Client is not allowed to monitor this
4485 DBG("Skipping client at it does not have the object permission to receive notification for this trigger");
4490 if (client
->uid
!= lttng_credentials_get_uid(trigger_creds
)) {
4491 DBG("Skipping client at it does not have the permission to receive notification for this trigger");
4495 DBG("Sending notification to client (fd = %i, %zu bytes)",
4497 msg_payload
.buffer
.size
);
4499 if (client_has_outbound_data_left(client
)) {
4501 * Outgoing data is already buffered for this client;
4502 * drop the notification and enqueue a "dropped
4503 * notification" message if this is the first dropped
4504 * notification since the socket spilled-over to the
4507 ret
= client_notification_overflow(client
);
4514 ret
= lttng_payload_copy(&msg_payload
, &client
->communication
.outbound
.payload
);
4520 transmission_status
= client_flush_outgoing_queue(client
);
4521 pthread_mutex_unlock(&client
->lock
);
4522 ret
= client_report(client
, transmission_status
, user_data
);
4525 goto end_unlock_list
;
4531 pthread_mutex_unlock(&client
->lock
);
4534 goto end_unlock_list
;
4540 pthread_mutex_unlock(&client_list
->lock
);
4542 lttng_payload_reset(&msg_payload
);
4546 static struct lttng_event_notifier_notification
*
4547 recv_one_event_notifier_notification(int notification_pipe_read_fd
, enum lttng_domain_type domain
)
4551 struct lttng_event_notifier_notification
*notification
= nullptr;
4552 char *capture_buffer
= nullptr;
4553 size_t capture_buffer_size
;
4554 void *reception_buffer
;
4555 size_t reception_size
;
4557 struct lttng_ust_abi_event_notifier_notification ust_notification
;
4558 struct lttng_kernel_abi_event_notifier_notification kernel_notification
;
4560 /* Init lttng_event_notifier_notification */
4562 case LTTNG_DOMAIN_UST
:
4563 reception_buffer
= (void *) &ust_notification
;
4564 reception_size
= sizeof(ust_notification
);
4566 case LTTNG_DOMAIN_KERNEL
:
4567 reception_buffer
= (void *) &kernel_notification
;
4568 reception_size
= sizeof(kernel_notification
);
4575 * The monitoring pipe only holds messages smaller than PIPE_BUF,
4576 * ensuring that read/write of tracer notifications are atomic.
4578 ret
= lttng_read(notification_pipe_read_fd
, reception_buffer
, reception_size
);
4579 if (ret
!= reception_size
) {
4580 PERROR("Failed to read from event source notification pipe: fd = %d, size to read = %zu, ret = %d",
4581 notification_pipe_read_fd
,
4589 case LTTNG_DOMAIN_UST
:
4590 token
= ust_notification
.token
;
4591 capture_buffer_size
= ust_notification
.capture_buf_size
;
4593 case LTTNG_DOMAIN_KERNEL
:
4594 token
= kernel_notification
.token
;
4595 capture_buffer_size
= kernel_notification
.capture_buf_size
;
4601 if (capture_buffer_size
== 0) {
4602 capture_buffer
= nullptr;
4606 if (capture_buffer_size
> MAX_CAPTURE_SIZE
) {
4607 ERR("Event notifier has a capture payload size which exceeds the maximum allowed size: capture_payload_size = %zu bytes, max allowed size = %d bytes",
4608 capture_buffer_size
,
4613 capture_buffer
= calloc
<char>(capture_buffer_size
);
4614 if (!capture_buffer
) {
4615 ERR("Failed to allocate capture buffer");
4619 /* Fetch additional payload (capture). */
4620 ret
= lttng_read(notification_pipe_read_fd
, capture_buffer
, capture_buffer_size
);
4621 if (ret
!= capture_buffer_size
) {
4622 ERR("Failed to read from event source pipe (fd = %i)", notification_pipe_read_fd
);
4627 notification
= lttng_event_notifier_notification_create(
4628 token
, domain
, capture_buffer
, capture_buffer_size
);
4629 if (notification
== nullptr) {
4634 * Ownership transfered to the lttng_event_notifier_notification object.
4636 capture_buffer
= nullptr;
4639 free(capture_buffer
);
4640 return notification
;
4644 dispatch_one_event_notifier_notification(struct notification_thread_state
*state
,
4645 struct lttng_event_notifier_notification
*notification
)
4647 struct cds_lfht_node
*node
;
4648 struct cds_lfht_iter iter
;
4649 struct notification_trigger_tokens_ht_element
*element
;
4650 struct lttng_evaluation
*evaluation
= nullptr;
4651 enum action_executor_status executor_status
;
4652 struct notification_client_list
*client_list
= nullptr;
4654 unsigned int capture_count
= 0;
4656 /* Find triggers associated with this token. */
4657 lttng::urcu::read_lock_guard read_lock
;
4658 cds_lfht_lookup(state
->trigger_tokens_ht
,
4659 hash_key_u64(¬ification
->tracer_token
, lttng_ht_seed
),
4660 match_trigger_token
,
4661 ¬ification
->tracer_token
,
4663 node
= cds_lfht_iter_get_node(&iter
);
4664 if (caa_unlikely(!node
)) {
4666 * This is not an error, slow consumption of the tracer
4667 * notifications can lead to situations where a trigger is
4668 * removed but we still get tracer notifications matching a
4669 * trigger that no longer exists.
4675 element
= caa_container_of(node
, struct notification_trigger_tokens_ht_element
, node
);
4677 if (lttng_condition_event_rule_matches_get_capture_descriptor_count(
4678 lttng_trigger_get_const_condition(element
->trigger
), &capture_count
) !=
4679 LTTNG_CONDITION_STATUS_OK
) {
4680 ERR("Failed to get capture count");
4685 if (!notification
->capture_buffer
&& capture_count
!= 0) {
4686 ERR("Expected capture but capture buffer is null");
4691 evaluation
= lttng_evaluation_event_rule_matches_create(
4692 lttng::utils::container_of(lttng_trigger_get_const_condition(element
->trigger
),
4693 <tng_condition_event_rule_matches::parent
),
4694 notification
->capture_buffer
,
4695 notification
->capture_buf_size
,
4698 if (evaluation
== nullptr) {
4699 ERR("Failed to create event rule matches evaluation while creating and enqueuing action executor job");
4704 client_list
= get_client_list_from_condition(
4705 state
, lttng_trigger_get_const_condition(element
->trigger
));
4706 executor_status
= action_executor_enqueue_trigger(
4707 state
->executor
, element
->trigger
, evaluation
, nullptr, client_list
);
4708 switch (executor_status
) {
4709 case ACTION_EXECUTOR_STATUS_OK
:
4712 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
4714 struct notification_client_list_element
*client_list_element
, *tmp
;
4717 * Not a fatal error; this is expected and simply means the
4718 * executor has too much work queued already.
4722 /* No clients subscribed to notifications for this trigger. */
4727 /* Warn clients that a notification (or more) was dropped. */
4728 pthread_mutex_lock(&client_list
->lock
);
4729 cds_list_for_each_entry_safe (
4730 client_list_element
, tmp
, &client_list
->clients_list
, node
) {
4731 enum client_transmission_status transmission_status
;
4732 struct notification_client
*client
= client_list_element
->client
;
4734 pthread_mutex_lock(&client
->lock
);
4735 ret
= client_notification_overflow(client
);
4741 transmission_status
= client_flush_outgoing_queue(client
);
4742 ret
= client_handle_transmission_status(client
, transmission_status
, state
);
4748 pthread_mutex_unlock(&client
->lock
);
4754 pthread_mutex_unlock(&client_list
->lock
);
4757 case ACTION_EXECUTOR_STATUS_INVALID
:
4758 case ACTION_EXECUTOR_STATUS_ERROR
:
4759 /* Fatal error, shut down everything. */
4760 ERR("Fatal error encoutered while enqueuing action to the action executor");
4764 /* Unhandled error. */
4769 notification_client_list_put(client_list
);
4774 static int handle_one_event_notifier_notification(struct notification_thread_state
*state
,
4776 enum lttng_domain_type domain
)
4779 struct lttng_event_notifier_notification
*notification
= nullptr;
4781 notification
= recv_one_event_notifier_notification(pipe
, domain
);
4782 if (notification
== nullptr) {
4783 /* Reception failed, don't consider it fatal. */
4784 ERR("Error receiving an event notifier notification from tracer: fd = %i, domain = %s",
4786 lttng_domain_type_str(domain
));
4790 ret
= dispatch_one_event_notifier_notification(state
, notification
);
4792 ERR("Error dispatching an event notifier notification from tracer: fd = %i, domain = %s",
4794 lttng_domain_type_str(domain
));
4799 lttng_event_notifier_notification_destroy(notification
);
4803 int handle_notification_thread_event_notification(struct notification_thread_state
*state
,
4805 enum lttng_domain_type domain
)
4807 return handle_one_event_notifier_notification(state
, pipe
, domain
);
4810 int handle_notification_thread_channel_sample(struct notification_thread_state
*state
,
4812 enum lttng_domain_type domain
)
4815 struct lttcomm_consumer_channel_monitor_msg sample_msg
;
4816 struct channel_info
*channel_info
= nullptr;
4817 struct cds_lfht_node
*node
;
4818 struct cds_lfht_iter iter
;
4819 struct lttng_channel_trigger_list
*channel_trigger_list
;
4820 struct lttng_session_trigger_list
*session_trigger_list
;
4821 struct lttng_trigger_list_element
*trigger_list_element
;
4822 bool previous_sample_available
= false;
4823 struct channel_state_sample channel_previous_sample
, channel_new_sample
;
4824 struct session_state_sample session_new_sample
;
4825 struct lttng_credentials channel_creds
= {};
4826 struct lttng_credentials session_creds
= {};
4827 struct session_info
*session
;
4828 lttng::urcu::read_lock_guard read_lock
;
4831 * The monitoring pipe only holds messages smaller than PIPE_BUF,
4832 * ensuring that read/write of sampling messages are atomic.
4834 ret
= lttng_read(pipe
, &sample_msg
, sizeof(sample_msg
));
4835 if (ret
!= sizeof(sample_msg
)) {
4836 ERR("Failed to read from monitoring pipe (fd = %i)", pipe
);
4842 channel_new_sample
.key
.key
= sample_msg
.key
;
4843 channel_new_sample
.key
.domain
= domain
;
4844 channel_new_sample
.highest_usage
= sample_msg
.highest
;
4845 channel_new_sample
.lowest_usage
= sample_msg
.lowest
;
4847 session
= get_session_info_by_id(state
, sample_msg
.session_id
);
4849 DBG("Received a sample for an unknown session from consumerd: session id = %" PRIu64
,
4850 sample_msg
.session_id
);
4854 session_new_sample
= session
->last_state_sample
;
4855 session_new_sample
.consumed_data_size
+= sample_msg
.consumed_since_last_sample
;
4857 .uid
= LTTNG_OPTIONAL_INIT_VALUE(session
->uid
),
4858 .gid
= LTTNG_OPTIONAL_INIT_VALUE(session
->gid
),
4861 session_trigger_list
= get_session_trigger_list(state
, session
->name
);
4862 LTTNG_ASSERT(session_trigger_list
);
4863 cds_list_for_each_entry (trigger_list_element
, &session_trigger_list
->list
, node
) {
4864 const struct lttng_condition
*condition
;
4865 struct lttng_trigger
*trigger
;
4866 struct notification_client_list
*client_list
= nullptr;
4867 struct lttng_evaluation
*evaluation
= nullptr;
4868 enum action_executor_status executor_status
;
4871 trigger
= trigger_list_element
->trigger
;
4872 condition
= lttng_trigger_get_const_condition(trigger
);
4873 LTTNG_ASSERT(condition
);
4875 ret
= evaluate_session_condition(
4876 condition
, session
, &session_new_sample
, &evaluation
);
4877 if (caa_unlikely(ret
)) {
4881 if (caa_likely(!evaluation
)) {
4886 * Ownership of `evaluation` transferred to the action executor
4887 * no matter the result. The callee acquires a reference to the
4888 * client list: we can release our own.
4890 client_list
= get_client_list_from_condition(state
, condition
);
4891 executor_status
= action_executor_enqueue_trigger(
4892 state
->executor
, trigger
, evaluation
, &session_creds
, client_list
);
4893 notification_client_list_put(client_list
);
4894 evaluation
= nullptr;
4895 switch (executor_status
) {
4896 case ACTION_EXECUTOR_STATUS_OK
:
4898 case ACTION_EXECUTOR_STATUS_ERROR
:
4899 case ACTION_EXECUTOR_STATUS_INVALID
:
4901 * TODO Add trigger identification (name/id) when
4902 * it is added to the API.
4904 ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
4907 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
4909 * TODO Add trigger identification (name/id) when
4910 * it is added to the API.
4912 * Not a fatal error.
4914 WARN("No space left when enqueuing action associated with buffer-condition trigger");
4922 /* Retrieve the channel's informations */
4923 cds_lfht_lookup(state
->channels_ht
,
4924 hash_channel_key(&channel_new_sample
.key
),
4926 &channel_new_sample
.key
,
4928 node
= cds_lfht_iter_get_node(&iter
);
4929 if (caa_unlikely(!node
)) {
4931 * Not an error since the consumer can push a sample to the pipe
4932 * and the rest of the session daemon could notify us of the
4933 * channel's destruction before we get a chance to process that
4936 DBG("Received a sample for an unknown channel from consumerd, key = %" PRIu64
4938 channel_new_sample
.key
.key
,
4939 lttng_domain_type_str(domain
));
4943 channel_info
= caa_container_of(node
, struct channel_info
, channels_ht_node
);
4944 DBG("Handling channel sample for channel %s (key = %" PRIu64
4945 ") in session %s (highest usage = %" PRIu64
", lowest usage = %" PRIu64
4946 ", consumed since last sample = %" PRIu64
")",
4948 channel_new_sample
.key
.key
,
4949 channel_info
->session_info
->name
,
4950 channel_new_sample
.highest_usage
,
4951 channel_new_sample
.lowest_usage
,
4952 sample_msg
.consumed_since_last_sample
);
4954 /* Retrieve the channel's last sample, if it exists, and update it. */
4955 cds_lfht_lookup(state
->channel_state_ht
,
4956 hash_channel_key(&channel_new_sample
.key
),
4957 match_channel_state_sample
,
4958 &channel_new_sample
.key
,
4960 node
= cds_lfht_iter_get_node(&iter
);
4961 if (caa_likely(node
)) {
4962 struct channel_state_sample
*stored_sample
;
4964 /* Update the sample stored. */
4966 caa_container_of(node
, struct channel_state_sample
, channel_state_ht_node
);
4968 memcpy(&channel_previous_sample
, stored_sample
, sizeof(channel_previous_sample
));
4969 stored_sample
->highest_usage
= channel_new_sample
.highest_usage
;
4970 stored_sample
->lowest_usage
= channel_new_sample
.lowest_usage
;
4971 previous_sample_available
= true;
4974 * This is the channel's first sample, allocate space for and
4975 * store the new sample.
4977 struct channel_state_sample
*stored_sample
;
4979 stored_sample
= zmalloc
<channel_state_sample
>();
4980 if (!stored_sample
) {
4985 memcpy(stored_sample
, &channel_new_sample
, sizeof(*stored_sample
));
4986 cds_lfht_node_init(&stored_sample
->channel_state_ht_node
);
4987 cds_lfht_add(state
->channel_state_ht
,
4988 hash_channel_key(&stored_sample
->key
),
4989 &stored_sample
->channel_state_ht_node
);
4992 /* Find triggers associated with this channel. */
4993 cds_lfht_lookup(state
->channel_triggers_ht
,
4994 hash_channel_key(&channel_new_sample
.key
),
4995 match_channel_trigger_list
,
4996 &channel_new_sample
.key
,
4998 node
= cds_lfht_iter_get_node(&iter
);
5001 channel_creds
= (typeof(channel_creds
)){
5002 .uid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->uid
),
5003 .gid
= LTTNG_OPTIONAL_INIT_VALUE(channel_info
->session_info
->gid
),
5006 channel_trigger_list
=
5007 caa_container_of(node
, struct lttng_channel_trigger_list
, channel_triggers_ht_node
);
5008 cds_list_for_each_entry (trigger_list_element
, &channel_trigger_list
->list
, node
) {
5009 const struct lttng_condition
*condition
;
5010 struct lttng_trigger
*trigger
;
5011 struct notification_client_list
*client_list
= nullptr;
5012 struct lttng_evaluation
*evaluation
= nullptr;
5013 enum action_executor_status executor_status
;
5016 trigger
= trigger_list_element
->trigger
;
5017 condition
= lttng_trigger_get_const_condition(trigger
);
5018 LTTNG_ASSERT(condition
);
5020 ret
= evaluate_buffer_condition(
5024 previous_sample_available
? &channel_previous_sample
: nullptr,
5025 &channel_new_sample
,
5027 if (caa_unlikely(ret
)) {
5031 if (caa_likely(!evaluation
)) {
5036 * Ownership of `evaluation` transferred to the action executor
5037 * no matter the result. The callee acquires a reference to the
5038 * client list: we can release our own.
5040 client_list
= get_client_list_from_condition(state
, condition
);
5041 executor_status
= action_executor_enqueue_trigger(
5042 state
->executor
, trigger
, evaluation
, &channel_creds
, client_list
);
5043 notification_client_list_put(client_list
);
5044 evaluation
= nullptr;
5045 switch (executor_status
) {
5046 case ACTION_EXECUTOR_STATUS_OK
:
5048 case ACTION_EXECUTOR_STATUS_ERROR
:
5049 case ACTION_EXECUTOR_STATUS_INVALID
:
5051 * TODO Add trigger identification (name/id) when
5052 * it is added to the API.
5054 ERR("Fatal error occurred while enqueuing action associated with buffer-condition trigger");
5057 case ACTION_EXECUTOR_STATUS_OVERFLOW
:
5059 * TODO Add trigger identification (name/id) when
5060 * it is added to the API.
5062 * Not a fatal error.
5064 WARN("No space left when enqueuing action associated with buffer-condition trigger");
5073 session
->last_state_sample
= session_new_sample
;
5075 session_info_put(session
);