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ab0ee2ca JG |
1 | /* |
2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | ||
18 | #define _LGPL_SOURCE | |
19 | #include <urcu.h> | |
20 | #include <urcu/rculfhash.h> | |
21 | ||
ab0ee2ca JG |
22 | #include <common/defaults.h> |
23 | #include <common/error.h> | |
24 | #include <common/futex.h> | |
25 | #include <common/unix.h> | |
26 | #include <common/dynamic-buffer.h> | |
27 | #include <common/hashtable/utils.h> | |
28 | #include <common/sessiond-comm/sessiond-comm.h> | |
29 | #include <common/macros.h> | |
30 | #include <lttng/condition/condition.h> | |
31 | #include <lttng/action/action.h> | |
32 | #include <lttng/notification/notification-internal.h> | |
33 | #include <lttng/condition/condition-internal.h> | |
34 | #include <lttng/condition/buffer-usage-internal.h> | |
35 | #include <lttng/notification/channel-internal.h> | |
fa7c4fcd | 36 | |
ab0ee2ca JG |
37 | #include <time.h> |
38 | #include <unistd.h> | |
39 | #include <assert.h> | |
40 | #include <inttypes.h> | |
44f2d7db | 41 | #include <fcntl.h> |
ab0ee2ca | 42 | |
fa7c4fcd JG |
43 | #include "notification-thread.h" |
44 | #include "notification-thread-events.h" | |
45 | #include "notification-thread-commands.h" | |
46 | #include "lttng-sessiond.h" | |
47 | #include "kernel.h" | |
48 | ||
ab0ee2ca JG |
49 | #define CLIENT_POLL_MASK_IN (LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP) |
50 | #define CLIENT_POLL_MASK_IN_OUT (CLIENT_POLL_MASK_IN | LPOLLOUT) | |
51 | ||
52 | struct lttng_trigger_list_element { | |
53 | struct lttng_trigger *trigger; | |
54 | struct cds_list_head node; | |
55 | }; | |
56 | ||
57 | struct lttng_channel_trigger_list { | |
58 | struct channel_key channel_key; | |
59 | struct cds_list_head list; | |
60 | struct cds_lfht_node channel_triggers_ht_node; | |
61 | }; | |
62 | ||
63 | struct lttng_trigger_ht_element { | |
64 | struct lttng_trigger *trigger; | |
65 | struct cds_lfht_node node; | |
66 | }; | |
67 | ||
68 | struct lttng_condition_list_element { | |
69 | struct lttng_condition *condition; | |
70 | struct cds_list_head node; | |
71 | }; | |
72 | ||
73 | struct notification_client_list_element { | |
74 | struct notification_client *client; | |
75 | struct cds_list_head node; | |
76 | }; | |
77 | ||
78 | struct notification_client_list { | |
79 | struct lttng_trigger *trigger; | |
80 | struct cds_list_head list; | |
81 | struct cds_lfht_node notification_trigger_ht_node; | |
82 | }; | |
83 | ||
84 | struct notification_client { | |
85 | int socket; | |
86 | /* Client protocol version. */ | |
87 | uint8_t major, minor; | |
88 | uid_t uid; | |
89 | gid_t gid; | |
90 | /* | |
6a00208d | 91 | * Indicates if the credentials and versions of the client have been |
ab0ee2ca JG |
92 | * checked. |
93 | */ | |
94 | bool validated; | |
95 | /* | |
96 | * Conditions to which the client's notification channel is subscribed. | |
97 | * List of struct lttng_condition_list_node. The condition member is | |
98 | * owned by the client. | |
99 | */ | |
100 | struct cds_list_head condition_list; | |
101 | struct cds_lfht_node client_socket_ht_node; | |
102 | struct { | |
103 | struct { | |
b5eb6b46 JG |
104 | /* |
105 | * During the reception of a message, the reception | |
106 | * buffers' "size" is set to contain the current | |
107 | * message's complete payload. | |
108 | */ | |
ab0ee2ca JG |
109 | struct lttng_dynamic_buffer buffer; |
110 | /* Bytes left to receive for the current message. */ | |
111 | size_t bytes_to_receive; | |
112 | /* Type of the message being received. */ | |
113 | enum lttng_notification_channel_message_type msg_type; | |
114 | /* | |
115 | * Indicates whether or not credentials are expected | |
116 | * from the client. | |
117 | */ | |
f950d02c | 118 | bool expect_creds; |
ab0ee2ca JG |
119 | /* |
120 | * Indicates whether or not credentials were received | |
121 | * from the client. | |
122 | */ | |
123 | bool creds_received; | |
b5eb6b46 | 124 | /* Only used during credentials reception. */ |
ab0ee2ca JG |
125 | lttng_sock_cred creds; |
126 | } inbound; | |
127 | struct { | |
128 | /* | |
129 | * Indicates whether or not a notification addressed to | |
130 | * this client was dropped because a command reply was | |
131 | * already buffered. | |
132 | * | |
133 | * A notification is dropped whenever the buffer is not | |
134 | * empty. | |
135 | */ | |
136 | bool dropped_notification; | |
137 | /* | |
138 | * Indicates whether or not a command reply is already | |
139 | * buffered. In this case, it means that the client is | |
140 | * not consuming command replies before emitting a new | |
141 | * one. This could be caused by a protocol error or a | |
142 | * misbehaving/malicious client. | |
143 | */ | |
144 | bool queued_command_reply; | |
145 | struct lttng_dynamic_buffer buffer; | |
146 | } outbound; | |
147 | } communication; | |
148 | }; | |
149 | ||
150 | struct channel_state_sample { | |
151 | struct channel_key key; | |
152 | struct cds_lfht_node channel_state_ht_node; | |
153 | uint64_t highest_usage; | |
154 | uint64_t lowest_usage; | |
155 | }; | |
156 | ||
f0225486 JR |
157 | static unsigned long hash_channel_key(struct channel_key *key); |
158 | static int evaluate_condition(struct lttng_condition *condition, | |
159 | struct lttng_evaluation **evaluation, | |
160 | struct notification_thread_state *state, | |
161 | struct channel_state_sample *previous_sample, | |
162 | struct channel_state_sample *latest_sample, | |
163 | uint64_t buffer_capacity); | |
164 | static | |
165 | int send_evaluation_to_clients(struct lttng_trigger *trigger, | |
166 | struct lttng_evaluation *evaluation, | |
167 | struct notification_client_list *client_list, | |
168 | struct notification_thread_state *state, | |
169 | uid_t channel_uid, gid_t channel_gid); | |
170 | ||
ab0ee2ca JG |
171 | static |
172 | int match_client(struct cds_lfht_node *node, const void *key) | |
173 | { | |
174 | /* This double-cast is intended to supress pointer-to-cast warning. */ | |
175 | int socket = (int) (intptr_t) key; | |
176 | struct notification_client *client; | |
177 | ||
178 | client = caa_container_of(node, struct notification_client, | |
179 | client_socket_ht_node); | |
180 | ||
181 | return !!(client->socket == socket); | |
182 | } | |
183 | ||
184 | static | |
185 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) | |
186 | { | |
187 | struct channel_key *channel_key = (struct channel_key *) key; | |
188 | struct lttng_channel_trigger_list *trigger_list; | |
189 | ||
190 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
191 | channel_triggers_ht_node); | |
192 | ||
193 | return !!((channel_key->key == trigger_list->channel_key.key) && | |
194 | (channel_key->domain == trigger_list->channel_key.domain)); | |
195 | } | |
196 | ||
197 | static | |
198 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) | |
199 | { | |
200 | struct channel_key *channel_key = (struct channel_key *) key; | |
201 | struct channel_state_sample *sample; | |
202 | ||
203 | sample = caa_container_of(node, struct channel_state_sample, | |
204 | channel_state_ht_node); | |
205 | ||
206 | return !!((channel_key->key == sample->key.key) && | |
207 | (channel_key->domain == sample->key.domain)); | |
208 | } | |
209 | ||
210 | static | |
211 | int match_channel_info(struct cds_lfht_node *node, const void *key) | |
212 | { | |
213 | struct channel_key *channel_key = (struct channel_key *) key; | |
214 | struct channel_info *channel_info; | |
215 | ||
216 | channel_info = caa_container_of(node, struct channel_info, | |
217 | channels_ht_node); | |
218 | ||
219 | return !!((channel_key->key == channel_info->key.key) && | |
220 | (channel_key->domain == channel_info->key.domain)); | |
221 | } | |
222 | ||
223 | static | |
224 | int match_condition(struct cds_lfht_node *node, const void *key) | |
225 | { | |
226 | struct lttng_condition *condition_key = (struct lttng_condition *) key; | |
227 | struct lttng_trigger_ht_element *trigger; | |
228 | struct lttng_condition *condition; | |
229 | ||
230 | trigger = caa_container_of(node, struct lttng_trigger_ht_element, | |
231 | node); | |
232 | condition = lttng_trigger_get_condition(trigger->trigger); | |
233 | assert(condition); | |
234 | ||
235 | return !!lttng_condition_is_equal(condition_key, condition); | |
236 | } | |
237 | ||
238 | static | |
239 | int match_client_list(struct cds_lfht_node *node, const void *key) | |
240 | { | |
241 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; | |
242 | struct notification_client_list *client_list; | |
243 | struct lttng_condition *condition; | |
244 | struct lttng_condition *condition_key = lttng_trigger_get_condition( | |
245 | trigger_key); | |
246 | ||
247 | assert(condition_key); | |
248 | ||
249 | client_list = caa_container_of(node, struct notification_client_list, | |
250 | notification_trigger_ht_node); | |
251 | condition = lttng_trigger_get_condition(client_list->trigger); | |
252 | ||
253 | return !!lttng_condition_is_equal(condition_key, condition); | |
254 | } | |
255 | ||
256 | static | |
257 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) | |
258 | { | |
259 | struct lttng_condition *condition_key = (struct lttng_condition *) key; | |
260 | struct notification_client_list *client_list; | |
261 | struct lttng_condition *condition; | |
262 | ||
263 | assert(condition_key); | |
264 | ||
265 | client_list = caa_container_of(node, struct notification_client_list, | |
266 | notification_trigger_ht_node); | |
267 | condition = lttng_trigger_get_condition(client_list->trigger); | |
268 | ||
269 | return !!lttng_condition_is_equal(condition_key, condition); | |
270 | } | |
271 | ||
272 | static | |
273 | unsigned long lttng_condition_buffer_usage_hash( | |
274 | struct lttng_condition *_condition) | |
275 | { | |
276 | unsigned long hash = 0; | |
277 | struct lttng_condition_buffer_usage *condition; | |
278 | ||
279 | condition = container_of(_condition, | |
280 | struct lttng_condition_buffer_usage, parent); | |
281 | ||
282 | if (condition->session_name) { | |
283 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); | |
284 | } | |
285 | if (condition->channel_name) { | |
8f56701f | 286 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
ab0ee2ca JG |
287 | } |
288 | if (condition->domain.set) { | |
289 | hash ^= hash_key_ulong( | |
290 | (void *) condition->domain.type, | |
291 | lttng_ht_seed); | |
292 | } | |
293 | if (condition->threshold_ratio.set) { | |
294 | uint64_t val; | |
295 | ||
296 | val = condition->threshold_ratio.value * (double) UINT32_MAX; | |
297 | hash ^= hash_key_u64(&val, lttng_ht_seed); | |
298 | } else if (condition->threshold_ratio.set) { | |
299 | uint64_t val; | |
300 | ||
301 | val = condition->threshold_bytes.value; | |
302 | hash ^= hash_key_u64(&val, lttng_ht_seed); | |
303 | } | |
304 | return hash; | |
305 | } | |
306 | ||
307 | /* | |
308 | * The lttng_condition hashing code is kept in this file (rather than | |
309 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we | |
310 | * don't want to link in liblttng-ctl. | |
311 | */ | |
312 | static | |
313 | unsigned long lttng_condition_hash(struct lttng_condition *condition) | |
314 | { | |
315 | switch (condition->type) { | |
316 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
317 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
318 | return lttng_condition_buffer_usage_hash(condition); | |
319 | default: | |
320 | ERR("[notification-thread] Unexpected condition type caught"); | |
321 | abort(); | |
322 | } | |
323 | } | |
324 | ||
f0225486 JR |
325 | static |
326 | unsigned long hash_channel_key(struct channel_key *key) | |
327 | { | |
328 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); | |
329 | unsigned long domain_hash = hash_key_ulong( | |
330 | (void *) (unsigned long) key->domain, lttng_ht_seed); | |
331 | ||
332 | return key_hash ^ domain_hash; | |
333 | } | |
334 | ||
ab0ee2ca JG |
335 | static |
336 | void channel_info_destroy(struct channel_info *channel_info) | |
337 | { | |
338 | if (!channel_info) { | |
339 | return; | |
340 | } | |
341 | ||
342 | if (channel_info->session_name) { | |
343 | free(channel_info->session_name); | |
344 | } | |
345 | if (channel_info->channel_name) { | |
346 | free(channel_info->channel_name); | |
347 | } | |
348 | free(channel_info); | |
349 | } | |
350 | ||
351 | static | |
352 | struct channel_info *channel_info_copy(struct channel_info *channel_info) | |
353 | { | |
354 | struct channel_info *copy = zmalloc(sizeof(*channel_info)); | |
355 | ||
356 | assert(channel_info); | |
357 | assert(channel_info->session_name); | |
358 | assert(channel_info->channel_name); | |
359 | ||
360 | if (!copy) { | |
361 | goto end; | |
362 | } | |
363 | ||
364 | memcpy(copy, channel_info, sizeof(*channel_info)); | |
365 | copy->session_name = NULL; | |
366 | copy->channel_name = NULL; | |
367 | ||
368 | copy->session_name = strdup(channel_info->session_name); | |
369 | if (!copy->session_name) { | |
370 | goto error; | |
371 | } | |
372 | copy->channel_name = strdup(channel_info->channel_name); | |
373 | if (!copy->channel_name) { | |
374 | goto error; | |
375 | } | |
376 | cds_lfht_node_init(&channel_info->channels_ht_node); | |
377 | end: | |
378 | return copy; | |
379 | error: | |
380 | channel_info_destroy(copy); | |
381 | return NULL; | |
382 | } | |
383 | ||
f0225486 JR |
384 | /* This function must be called with the RCU read lock held. */ |
385 | static | |
386 | int evaluate_condition_for_client(struct lttng_trigger *trigger, | |
387 | struct lttng_condition *condition, | |
388 | struct notification_client *client, | |
389 | struct notification_thread_state *state) | |
390 | { | |
391 | int ret; | |
392 | struct cds_lfht_iter iter; | |
393 | struct cds_lfht_node *node; | |
394 | struct channel_info *channel_info = NULL; | |
395 | struct channel_key *channel_key = NULL; | |
396 | struct channel_state_sample *last_sample = NULL; | |
397 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; | |
398 | struct lttng_evaluation *evaluation = NULL; | |
399 | struct notification_client_list client_list = { 0 }; | |
400 | struct notification_client_list_element client_list_element = { 0 }; | |
401 | ||
402 | assert(trigger); | |
403 | assert(condition); | |
404 | assert(client); | |
405 | assert(state); | |
406 | ||
407 | /* Find the channel associated with the trigger. */ | |
408 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, | |
409 | channel_trigger_list , channel_triggers_ht_node) { | |
410 | struct lttng_trigger_list_element *element; | |
411 | ||
412 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { | |
413 | struct lttng_condition *current_condition = | |
414 | lttng_trigger_get_condition( | |
415 | element->trigger); | |
416 | ||
417 | assert(current_condition); | |
418 | if (!lttng_condition_is_equal(condition, | |
419 | current_condition)) { | |
420 | continue; | |
421 | } | |
422 | ||
423 | /* Found the trigger, save the channel key. */ | |
424 | channel_key = &channel_trigger_list->channel_key; | |
425 | break; | |
426 | } | |
427 | if (channel_key) { | |
428 | /* The channel key was found stop iteration. */ | |
429 | break; | |
430 | } | |
431 | } | |
432 | ||
433 | if (!channel_key){ | |
434 | /* No channel found; normal exit. */ | |
435 | DBG("[notification-thread] No channel associated with newly subscribed-to condition"); | |
436 | ret = 0; | |
437 | goto end; | |
438 | } | |
439 | ||
440 | /* Fetch channel info for the matching channel. */ | |
441 | cds_lfht_lookup(state->channels_ht, | |
442 | hash_channel_key(channel_key), | |
443 | match_channel_info, | |
444 | channel_key, | |
445 | &iter); | |
446 | node = cds_lfht_iter_get_node(&iter); | |
447 | assert(node); | |
448 | channel_info = caa_container_of(node, struct channel_info, | |
449 | channels_ht_node); | |
450 | ||
451 | /* Retrieve the channel's last sample, if it exists. */ | |
452 | cds_lfht_lookup(state->channel_state_ht, | |
453 | hash_channel_key(channel_key), | |
454 | match_channel_state_sample, | |
455 | channel_key, | |
456 | &iter); | |
457 | node = cds_lfht_iter_get_node(&iter); | |
458 | if (node) { | |
459 | last_sample = caa_container_of(node, | |
460 | struct channel_state_sample, | |
461 | channel_state_ht_node); | |
462 | } else { | |
463 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ | |
464 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); | |
465 | ret = 0; | |
466 | goto end; | |
467 | } | |
468 | ||
469 | ret = evaluate_condition(condition, &evaluation, state, NULL, | |
470 | last_sample, channel_info->capacity); | |
471 | if (ret) { | |
e7d6cdaa | 472 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
f0225486 JR |
473 | goto end; |
474 | } | |
475 | ||
476 | if (!evaluation) { | |
477 | /* Evaluation yielded nothing. Normal exit. */ | |
478 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); | |
479 | ret = 0; | |
480 | goto end; | |
481 | } | |
482 | ||
483 | /* | |
484 | * Create a temporary client list with the client currently | |
485 | * subscribing. | |
486 | */ | |
487 | cds_lfht_node_init(&client_list.notification_trigger_ht_node); | |
488 | CDS_INIT_LIST_HEAD(&client_list.list); | |
489 | client_list.trigger = trigger; | |
490 | ||
491 | CDS_INIT_LIST_HEAD(&client_list_element.node); | |
492 | client_list_element.client = client; | |
493 | cds_list_add(&client_list_element.node, &client_list.list); | |
494 | ||
495 | /* Send evaluation result to the newly-subscribed client. */ | |
496 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); | |
497 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, | |
498 | state, channel_info->uid, channel_info->gid); | |
499 | ||
500 | end: | |
501 | return ret; | |
502 | } | |
503 | ||
ab0ee2ca JG |
504 | static |
505 | int notification_thread_client_subscribe(struct notification_client *client, | |
506 | struct lttng_condition *condition, | |
507 | struct notification_thread_state *state, | |
508 | enum lttng_notification_channel_status *_status) | |
509 | { | |
510 | int ret = 0; | |
511 | struct cds_lfht_iter iter; | |
512 | struct cds_lfht_node *node; | |
513 | struct notification_client_list *client_list; | |
514 | struct lttng_condition_list_element *condition_list_element = NULL; | |
515 | struct notification_client_list_element *client_list_element = NULL; | |
516 | enum lttng_notification_channel_status status = | |
517 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
518 | ||
519 | /* | |
520 | * Ensure that the client has not already subscribed to this condition | |
521 | * before. | |
522 | */ | |
523 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { | |
524 | if (lttng_condition_is_equal(condition_list_element->condition, | |
525 | condition)) { | |
526 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; | |
527 | goto end; | |
528 | } | |
529 | } | |
530 | ||
531 | condition_list_element = zmalloc(sizeof(*condition_list_element)); | |
532 | if (!condition_list_element) { | |
533 | ret = -1; | |
534 | goto error; | |
535 | } | |
536 | client_list_element = zmalloc(sizeof(*client_list_element)); | |
537 | if (!client_list_element) { | |
538 | ret = -1; | |
539 | goto error; | |
540 | } | |
541 | ||
542 | rcu_read_lock(); | |
543 | ||
544 | /* | |
545 | * Add the newly-subscribed condition to the client's subscription list. | |
546 | */ | |
547 | CDS_INIT_LIST_HEAD(&condition_list_element->node); | |
548 | condition_list_element->condition = condition; | |
549 | cds_list_add(&condition_list_element->node, &client->condition_list); | |
550 | ||
ab0ee2ca JG |
551 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
552 | lttng_condition_hash(condition), | |
553 | match_client_list_condition, | |
554 | condition, | |
555 | &iter); | |
556 | node = cds_lfht_iter_get_node(&iter); | |
557 | if (!node) { | |
c3dce007 | 558 | free(client_list_element); |
ab0ee2ca JG |
559 | goto end_unlock; |
560 | } | |
561 | ||
562 | client_list = caa_container_of(node, struct notification_client_list, | |
563 | notification_trigger_ht_node); | |
f0225486 JR |
564 | if (evaluate_condition_for_client(client_list->trigger, condition, |
565 | client, state)) { | |
566 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); | |
567 | ret = -1; | |
568 | goto end_unlock; | |
569 | } | |
570 | ||
571 | /* | |
572 | * Add the client to the list of clients interested in a given trigger | |
573 | * if a "notification" trigger with a corresponding condition was | |
574 | * added prior. | |
575 | */ | |
ab0ee2ca JG |
576 | client_list_element->client = client; |
577 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
578 | cds_list_add(&client_list_element->node, &client_list->list); | |
579 | end_unlock: | |
580 | rcu_read_unlock(); | |
581 | end: | |
582 | if (_status) { | |
583 | *_status = status; | |
584 | } | |
585 | return ret; | |
586 | error: | |
587 | free(condition_list_element); | |
588 | free(client_list_element); | |
589 | return ret; | |
590 | } | |
591 | ||
592 | static | |
593 | int notification_thread_client_unsubscribe( | |
594 | struct notification_client *client, | |
595 | struct lttng_condition *condition, | |
596 | struct notification_thread_state *state, | |
597 | enum lttng_notification_channel_status *_status) | |
598 | { | |
599 | struct cds_lfht_iter iter; | |
600 | struct cds_lfht_node *node; | |
601 | struct notification_client_list *client_list; | |
602 | struct lttng_condition_list_element *condition_list_element, | |
603 | *condition_tmp; | |
604 | struct notification_client_list_element *client_list_element, | |
605 | *client_tmp; | |
606 | bool condition_found = false; | |
607 | enum lttng_notification_channel_status status = | |
608 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
609 | ||
610 | /* Remove the condition from the client's condition list. */ | |
611 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, | |
612 | &client->condition_list, node) { | |
613 | if (!lttng_condition_is_equal(condition_list_element->condition, | |
614 | condition)) { | |
615 | continue; | |
616 | } | |
617 | ||
618 | cds_list_del(&condition_list_element->node); | |
619 | /* | |
620 | * The caller may be iterating on the client's conditions to | |
621 | * tear down a client's connection. In this case, the condition | |
622 | * will be destroyed at the end. | |
623 | */ | |
624 | if (condition != condition_list_element->condition) { | |
625 | lttng_condition_destroy( | |
626 | condition_list_element->condition); | |
627 | } | |
628 | free(condition_list_element); | |
629 | condition_found = true; | |
630 | break; | |
631 | } | |
632 | ||
633 | if (!condition_found) { | |
634 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; | |
635 | goto end; | |
636 | } | |
637 | ||
638 | /* | |
639 | * Remove the client from the list of clients interested the trigger | |
640 | * matching the condition. | |
641 | */ | |
642 | rcu_read_lock(); | |
643 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
644 | lttng_condition_hash(condition), | |
645 | match_client_list_condition, | |
646 | condition, | |
647 | &iter); | |
648 | node = cds_lfht_iter_get_node(&iter); | |
649 | if (!node) { | |
650 | goto end_unlock; | |
651 | } | |
652 | ||
653 | client_list = caa_container_of(node, struct notification_client_list, | |
654 | notification_trigger_ht_node); | |
655 | cds_list_for_each_entry_safe(client_list_element, client_tmp, | |
656 | &client_list->list, node) { | |
657 | if (client_list_element->client->socket != client->socket) { | |
658 | continue; | |
659 | } | |
660 | cds_list_del(&client_list_element->node); | |
661 | free(client_list_element); | |
662 | break; | |
663 | } | |
664 | end_unlock: | |
665 | rcu_read_unlock(); | |
666 | end: | |
667 | lttng_condition_destroy(condition); | |
668 | if (_status) { | |
669 | *_status = status; | |
670 | } | |
671 | return 0; | |
672 | } | |
673 | ||
674 | static | |
675 | void notification_client_destroy(struct notification_client *client, | |
676 | struct notification_thread_state *state) | |
677 | { | |
678 | struct lttng_condition_list_element *condition_list_element, *tmp; | |
679 | ||
680 | if (!client) { | |
681 | return; | |
682 | } | |
683 | ||
684 | /* Release all conditions to which the client was subscribed. */ | |
685 | cds_list_for_each_entry_safe(condition_list_element, tmp, | |
686 | &client->condition_list, node) { | |
687 | (void) notification_thread_client_unsubscribe(client, | |
688 | condition_list_element->condition, state, NULL); | |
689 | } | |
690 | ||
691 | if (client->socket >= 0) { | |
692 | (void) lttcomm_close_unix_sock(client->socket); | |
693 | } | |
694 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); | |
695 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); | |
696 | free(client); | |
697 | } | |
698 | ||
699 | /* | |
700 | * Call with rcu_read_lock held (and hold for the lifetime of the returned | |
701 | * client pointer). | |
702 | */ | |
703 | static | |
704 | struct notification_client *get_client_from_socket(int socket, | |
705 | struct notification_thread_state *state) | |
706 | { | |
707 | struct cds_lfht_iter iter; | |
708 | struct cds_lfht_node *node; | |
709 | struct notification_client *client = NULL; | |
710 | ||
711 | cds_lfht_lookup(state->client_socket_ht, | |
712 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), | |
713 | match_client, | |
714 | (void *) (unsigned long) socket, | |
715 | &iter); | |
716 | node = cds_lfht_iter_get_node(&iter); | |
717 | if (!node) { | |
718 | goto end; | |
719 | } | |
720 | ||
721 | client = caa_container_of(node, struct notification_client, | |
722 | client_socket_ht_node); | |
723 | end: | |
724 | return client; | |
725 | } | |
726 | ||
727 | static | |
728 | bool trigger_applies_to_channel(struct lttng_trigger *trigger, | |
729 | struct channel_info *info) | |
730 | { | |
731 | enum lttng_condition_status status; | |
732 | struct lttng_condition *condition; | |
733 | const char *trigger_session_name = NULL; | |
734 | const char *trigger_channel_name = NULL; | |
735 | enum lttng_domain_type trigger_domain; | |
736 | ||
737 | condition = lttng_trigger_get_condition(trigger); | |
738 | if (!condition) { | |
739 | goto fail; | |
740 | } | |
741 | ||
742 | switch (lttng_condition_get_type(condition)) { | |
743 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
744 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
745 | break; | |
746 | default: | |
747 | goto fail; | |
748 | } | |
749 | ||
750 | status = lttng_condition_buffer_usage_get_domain_type(condition, | |
751 | &trigger_domain); | |
752 | assert(status == LTTNG_CONDITION_STATUS_OK); | |
753 | if (info->key.domain != trigger_domain) { | |
754 | goto fail; | |
755 | } | |
756 | ||
757 | status = lttng_condition_buffer_usage_get_session_name( | |
758 | condition, &trigger_session_name); | |
759 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_session_name); | |
760 | ||
761 | status = lttng_condition_buffer_usage_get_channel_name( | |
762 | condition, &trigger_channel_name); | |
763 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); | |
764 | ||
765 | if (strcmp(info->session_name, trigger_session_name)) { | |
766 | goto fail; | |
767 | } | |
768 | if (strcmp(info->channel_name, trigger_channel_name)) { | |
769 | goto fail; | |
770 | } | |
771 | ||
772 | return true; | |
773 | fail: | |
774 | return false; | |
775 | } | |
776 | ||
777 | static | |
778 | bool trigger_applies_to_client(struct lttng_trigger *trigger, | |
779 | struct notification_client *client) | |
780 | { | |
781 | bool applies = false; | |
782 | struct lttng_condition_list_element *condition_list_element; | |
783 | ||
784 | cds_list_for_each_entry(condition_list_element, &client->condition_list, | |
785 | node) { | |
786 | applies = lttng_condition_is_equal( | |
787 | condition_list_element->condition, | |
788 | lttng_trigger_get_condition(trigger)); | |
789 | if (applies) { | |
790 | break; | |
791 | } | |
792 | } | |
793 | return applies; | |
794 | } | |
795 | ||
ab0ee2ca JG |
796 | static |
797 | int handle_notification_thread_command_add_channel( | |
798 | struct notification_thread_state *state, | |
799 | struct channel_info *channel_info, | |
800 | enum lttng_error_code *cmd_result) | |
801 | { | |
802 | struct cds_list_head trigger_list; | |
803 | struct channel_info *new_channel_info; | |
804 | struct channel_key *channel_key; | |
805 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; | |
806 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
807 | int trigger_count = 0; | |
808 | struct cds_lfht_iter iter; | |
809 | ||
810 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", | |
811 | channel_info->channel_name, channel_info->session_name, | |
812 | channel_info->key.key, channel_info->key.domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
813 | ||
814 | CDS_INIT_LIST_HEAD(&trigger_list); | |
815 | ||
816 | new_channel_info = channel_info_copy(channel_info); | |
817 | if (!new_channel_info) { | |
818 | goto error; | |
819 | } | |
820 | ||
821 | channel_key = &new_channel_info->key; | |
822 | ||
823 | /* Build a list of all triggers applying to the new channel. */ | |
824 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
825 | node) { | |
826 | struct lttng_trigger_list_element *new_element; | |
827 | ||
828 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, | |
829 | channel_info)) { | |
830 | continue; | |
831 | } | |
832 | ||
833 | new_element = zmalloc(sizeof(*new_element)); | |
834 | if (!new_element) { | |
835 | goto error; | |
836 | } | |
837 | CDS_INIT_LIST_HEAD(&new_element->node); | |
838 | new_element->trigger = trigger_ht_element->trigger; | |
839 | cds_list_add(&new_element->node, &trigger_list); | |
840 | trigger_count++; | |
841 | } | |
842 | ||
843 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", | |
844 | trigger_count); | |
845 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); | |
846 | if (!channel_trigger_list) { | |
847 | goto error; | |
848 | } | |
849 | channel_trigger_list->channel_key = *channel_key; | |
850 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); | |
851 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); | |
852 | cds_list_splice(&trigger_list, &channel_trigger_list->list); | |
853 | ||
854 | rcu_read_lock(); | |
855 | /* Add channel to the channel_ht which owns the channel_infos. */ | |
856 | cds_lfht_add(state->channels_ht, | |
857 | hash_channel_key(channel_key), | |
858 | &new_channel_info->channels_ht_node); | |
859 | /* | |
860 | * Add the list of triggers associated with this channel to the | |
861 | * channel_triggers_ht. | |
862 | */ | |
863 | cds_lfht_add(state->channel_triggers_ht, | |
864 | hash_channel_key(channel_key), | |
865 | &channel_trigger_list->channel_triggers_ht_node); | |
866 | rcu_read_unlock(); | |
867 | *cmd_result = LTTNG_OK; | |
868 | return 0; | |
869 | error: | |
870 | /* Empty trigger list */ | |
871 | channel_info_destroy(new_channel_info); | |
872 | return 1; | |
873 | } | |
874 | ||
875 | static | |
876 | int handle_notification_thread_command_remove_channel( | |
877 | struct notification_thread_state *state, | |
878 | uint64_t channel_key, enum lttng_domain_type domain, | |
879 | enum lttng_error_code *cmd_result) | |
880 | { | |
881 | struct cds_lfht_node *node; | |
882 | struct cds_lfht_iter iter; | |
883 | struct lttng_channel_trigger_list *trigger_list; | |
884 | struct lttng_trigger_list_element *trigger_list_element, *tmp; | |
885 | struct channel_key key = { .key = channel_key, .domain = domain }; | |
886 | struct channel_info *channel_info; | |
887 | ||
888 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", | |
889 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
890 | ||
891 | rcu_read_lock(); | |
892 | ||
893 | cds_lfht_lookup(state->channel_triggers_ht, | |
894 | hash_channel_key(&key), | |
895 | match_channel_trigger_list, | |
896 | &key, | |
897 | &iter); | |
898 | node = cds_lfht_iter_get_node(&iter); | |
899 | /* | |
900 | * There is a severe internal error if we are being asked to remove a | |
901 | * channel that doesn't exist. | |
902 | */ | |
903 | if (!node) { | |
904 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); | |
905 | goto end; | |
906 | } | |
907 | ||
908 | /* Free the list of triggers associated with this channel. */ | |
909 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
910 | channel_triggers_ht_node); | |
911 | cds_list_for_each_entry_safe(trigger_list_element, tmp, | |
912 | &trigger_list->list, node) { | |
913 | cds_list_del(&trigger_list_element->node); | |
914 | free(trigger_list_element); | |
915 | } | |
916 | cds_lfht_del(state->channel_triggers_ht, node); | |
917 | free(trigger_list); | |
918 | ||
919 | /* Free sampled channel state. */ | |
920 | cds_lfht_lookup(state->channel_state_ht, | |
921 | hash_channel_key(&key), | |
922 | match_channel_state_sample, | |
923 | &key, | |
924 | &iter); | |
925 | node = cds_lfht_iter_get_node(&iter); | |
926 | /* | |
927 | * This is expected to be NULL if the channel is destroyed before we | |
928 | * received a sample. | |
929 | */ | |
930 | if (node) { | |
931 | struct channel_state_sample *sample = caa_container_of(node, | |
932 | struct channel_state_sample, | |
933 | channel_state_ht_node); | |
934 | ||
935 | cds_lfht_del(state->channel_state_ht, node); | |
936 | free(sample); | |
937 | } | |
938 | ||
939 | /* Remove the channel from the channels_ht and free it. */ | |
940 | cds_lfht_lookup(state->channels_ht, | |
941 | hash_channel_key(&key), | |
942 | match_channel_info, | |
943 | &key, | |
944 | &iter); | |
945 | node = cds_lfht_iter_get_node(&iter); | |
946 | assert(node); | |
947 | channel_info = caa_container_of(node, struct channel_info, | |
948 | channels_ht_node); | |
949 | cds_lfht_del(state->channels_ht, node); | |
950 | channel_info_destroy(channel_info); | |
951 | end: | |
952 | rcu_read_unlock(); | |
953 | *cmd_result = LTTNG_OK; | |
954 | return 0; | |
955 | } | |
956 | ||
fa7c4fcd JG |
957 | static |
958 | int condition_is_supported(struct lttng_condition *condition) | |
959 | { | |
960 | int ret; | |
961 | ||
962 | switch (lttng_condition_get_type(condition)) { | |
963 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
964 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
965 | { | |
966 | enum lttng_domain_type domain; | |
967 | ||
968 | ret = lttng_condition_buffer_usage_get_domain_type(condition, | |
969 | &domain); | |
970 | if (ret) { | |
971 | ret = -1; | |
972 | goto end; | |
973 | } | |
974 | ||
975 | if (domain != LTTNG_DOMAIN_KERNEL) { | |
976 | ret = 1; | |
977 | goto end; | |
978 | } | |
979 | ||
980 | /* | |
981 | * Older kernel tracers don't expose the API to monitor their | |
982 | * buffers. Therefore, we reject triggers that require that | |
983 | * mechanism to be available to be evaluated. | |
984 | */ | |
985 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( | |
986 | kernel_tracer_fd); | |
987 | break; | |
988 | } | |
989 | default: | |
990 | ret = 1; | |
991 | } | |
992 | end: | |
993 | return ret; | |
994 | } | |
995 | ||
ab0ee2ca JG |
996 | /* |
997 | * FIXME A client's credentials are not checked when registering a trigger, nor | |
998 | * are they stored alongside with the trigger. | |
999 | * | |
fa7c4fcd | 1000 | * The effects of this are benign since: |
ab0ee2ca JG |
1001 | * - The client will succeed in registering the trigger, as it is valid, |
1002 | * - The trigger will, internally, be bound to the channel, | |
1003 | * - The notifications will not be sent since the client's credentials | |
1004 | * are checked against the channel at that moment. | |
fa7c4fcd JG |
1005 | * |
1006 | * If this function returns a non-zero value, it means something is | |
1007 | * fundamentally and the whole subsystem/thread will be torn down. | |
1008 | * | |
1009 | * If a non-fatal error occurs, just set the cmd_result to the appropriate | |
1010 | * error code. | |
ab0ee2ca JG |
1011 | */ |
1012 | static | |
1013 | int handle_notification_thread_command_register_trigger( | |
1014 | struct notification_thread_state *state, | |
1015 | struct lttng_trigger *trigger, | |
1016 | enum lttng_error_code *cmd_result) | |
1017 | { | |
1018 | int ret = 0; | |
1019 | struct lttng_condition *condition; | |
1020 | struct notification_client *client; | |
1021 | struct notification_client_list *client_list = NULL; | |
1022 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1023 | struct notification_client_list_element *client_list_element, *tmp; | |
1024 | struct cds_lfht_node *node; | |
1025 | struct cds_lfht_iter iter; | |
1026 | struct channel_info *channel; | |
1027 | bool free_trigger = true; | |
1028 | ||
1029 | rcu_read_lock(); | |
1030 | ||
1031 | condition = lttng_trigger_get_condition(trigger); | |
fa7c4fcd JG |
1032 | assert(condition); |
1033 | ||
1034 | ret = condition_is_supported(condition); | |
1035 | if (ret < 0) { | |
1036 | goto error; | |
1037 | } else if (ret == 0) { | |
1038 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; | |
1039 | goto error; | |
1040 | } else { | |
1041 | /* Feature is supported, continue. */ | |
1042 | ret = 0; | |
1043 | } | |
1044 | ||
ab0ee2ca JG |
1045 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
1046 | if (!trigger_ht_element) { | |
1047 | ret = -1; | |
1048 | goto error; | |
1049 | } | |
1050 | ||
1051 | /* Add trigger to the trigger_ht. */ | |
1052 | cds_lfht_node_init(&trigger_ht_element->node); | |
1053 | trigger_ht_element->trigger = trigger; | |
1054 | ||
1055 | node = cds_lfht_add_unique(state->triggers_ht, | |
1056 | lttng_condition_hash(condition), | |
1057 | match_condition, | |
1058 | condition, | |
1059 | &trigger_ht_element->node); | |
1060 | if (node != &trigger_ht_element->node) { | |
1061 | /* Not a fatal error, simply report it to the client. */ | |
1062 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; | |
1063 | goto error_free_ht_element; | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * Ownership of the trigger and of its wrapper was transfered to | |
1068 | * the triggers_ht. | |
1069 | */ | |
1070 | trigger_ht_element = NULL; | |
1071 | free_trigger = false; | |
1072 | ||
1073 | /* | |
1074 | * The rest only applies to triggers that have a "notify" action. | |
1075 | * It is not skipped as this is the only action type currently | |
1076 | * supported. | |
1077 | */ | |
1078 | client_list = zmalloc(sizeof(*client_list)); | |
1079 | if (!client_list) { | |
1080 | ret = -1; | |
1081 | goto error_free_ht_element; | |
1082 | } | |
1083 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); | |
1084 | CDS_INIT_LIST_HEAD(&client_list->list); | |
1085 | client_list->trigger = trigger; | |
1086 | ||
1087 | /* Build a list of clients to which this new trigger applies. */ | |
1088 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1089 | client_socket_ht_node) { | |
1090 | if (!trigger_applies_to_client(trigger, client)) { | |
1091 | continue; | |
1092 | } | |
1093 | ||
1094 | client_list_element = zmalloc(sizeof(*client_list_element)); | |
1095 | if (!client_list_element) { | |
1096 | ret = -1; | |
1097 | goto error_free_client_list; | |
1098 | } | |
1099 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
1100 | client_list_element->client = client; | |
1101 | cds_list_add(&client_list_element->node, &client_list->list); | |
1102 | } | |
1103 | ||
1104 | cds_lfht_add(state->notification_trigger_clients_ht, | |
1105 | lttng_condition_hash(condition), | |
1106 | &client_list->notification_trigger_ht_node); | |
1107 | /* | |
1108 | * Client list ownership transferred to the | |
1109 | * notification_trigger_clients_ht. | |
1110 | */ | |
1111 | client_list = NULL; | |
1112 | ||
1113 | /* | |
1114 | * Add the trigger to list of triggers bound to the channels currently | |
1115 | * known. | |
1116 | */ | |
1117 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, | |
1118 | channels_ht_node) { | |
1119 | struct lttng_trigger_list_element *trigger_list_element; | |
1120 | struct lttng_channel_trigger_list *trigger_list; | |
1121 | ||
1122 | if (!trigger_applies_to_channel(trigger, channel)) { | |
1123 | continue; | |
1124 | } | |
1125 | ||
1126 | cds_lfht_lookup(state->channel_triggers_ht, | |
1127 | hash_channel_key(&channel->key), | |
1128 | match_channel_trigger_list, | |
1129 | &channel->key, | |
1130 | &iter); | |
1131 | node = cds_lfht_iter_get_node(&iter); | |
1132 | assert(node); | |
ab0ee2ca JG |
1133 | trigger_list = caa_container_of(node, |
1134 | struct lttng_channel_trigger_list, | |
1135 | channel_triggers_ht_node); | |
1136 | ||
1137 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); | |
1138 | if (!trigger_list_element) { | |
1139 | ret = -1; | |
1140 | goto error_free_client_list; | |
1141 | } | |
1142 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); | |
1143 | trigger_list_element->trigger = trigger; | |
1144 | cds_list_add(&trigger_list_element->node, &trigger_list->list); | |
f0225486 | 1145 | |
ab0ee2ca JG |
1146 | /* A trigger can only apply to one channel. */ |
1147 | break; | |
1148 | } | |
1149 | ||
1150 | *cmd_result = LTTNG_OK; | |
1151 | error_free_client_list: | |
1152 | if (client_list) { | |
1153 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1154 | &client_list->list, node) { | |
1155 | free(client_list_element); | |
1156 | } | |
1157 | free(client_list); | |
1158 | } | |
1159 | error_free_ht_element: | |
1160 | free(trigger_ht_element); | |
1161 | error: | |
1162 | if (free_trigger) { | |
1163 | struct lttng_action *action = lttng_trigger_get_action(trigger); | |
1164 | ||
1165 | lttng_condition_destroy(condition); | |
1166 | lttng_action_destroy(action); | |
1167 | lttng_trigger_destroy(trigger); | |
1168 | } | |
1169 | rcu_read_unlock(); | |
1170 | return ret; | |
1171 | } | |
1172 | ||
7c2340da | 1173 | static |
ab0ee2ca JG |
1174 | int handle_notification_thread_command_unregister_trigger( |
1175 | struct notification_thread_state *state, | |
1176 | struct lttng_trigger *trigger, | |
1177 | enum lttng_error_code *_cmd_reply) | |
1178 | { | |
1179 | struct cds_lfht_iter iter; | |
1180 | struct cds_lfht_node *node, *triggers_ht_node; | |
1181 | struct lttng_channel_trigger_list *trigger_list; | |
1182 | struct notification_client_list *client_list; | |
1183 | struct notification_client_list_element *client_list_element, *tmp; | |
1184 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1185 | struct lttng_condition *condition = lttng_trigger_get_condition( | |
1186 | trigger); | |
1187 | struct lttng_action *action; | |
1188 | enum lttng_error_code cmd_reply; | |
1189 | ||
1190 | rcu_read_lock(); | |
1191 | ||
1192 | cds_lfht_lookup(state->triggers_ht, | |
1193 | lttng_condition_hash(condition), | |
1194 | match_condition, | |
1195 | condition, | |
1196 | &iter); | |
1197 | triggers_ht_node = cds_lfht_iter_get_node(&iter); | |
1198 | if (!triggers_ht_node) { | |
1199 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; | |
1200 | goto end; | |
1201 | } else { | |
1202 | cmd_reply = LTTNG_OK; | |
1203 | } | |
1204 | ||
1205 | /* Remove trigger from channel_triggers_ht. */ | |
1206 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, | |
1207 | channel_triggers_ht_node) { | |
1208 | struct lttng_trigger_list_element *trigger_element, *tmp; | |
1209 | ||
1210 | cds_list_for_each_entry_safe(trigger_element, tmp, | |
1211 | &trigger_list->list, node) { | |
1212 | struct lttng_condition *current_condition = | |
1213 | lttng_trigger_get_condition( | |
1214 | trigger_element->trigger); | |
1215 | ||
1216 | assert(current_condition); | |
1217 | if (!lttng_condition_is_equal(condition, | |
1218 | current_condition)) { | |
1219 | continue; | |
1220 | } | |
1221 | ||
1222 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); | |
1223 | cds_list_del(&trigger_element->node); | |
f0225486 JR |
1224 | /* A trigger can only appear once per channel */ |
1225 | break; | |
ab0ee2ca JG |
1226 | } |
1227 | } | |
1228 | ||
1229 | /* | |
1230 | * Remove and release the client list from | |
1231 | * notification_trigger_clients_ht. | |
1232 | */ | |
1233 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
1234 | lttng_condition_hash(condition), | |
1235 | match_client_list, | |
1236 | trigger, | |
1237 | &iter); | |
1238 | node = cds_lfht_iter_get_node(&iter); | |
1239 | assert(node); | |
1240 | client_list = caa_container_of(node, struct notification_client_list, | |
1241 | notification_trigger_ht_node); | |
1242 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1243 | &client_list->list, node) { | |
1244 | free(client_list_element); | |
1245 | } | |
1246 | cds_lfht_del(state->notification_trigger_clients_ht, node); | |
1247 | free(client_list); | |
1248 | ||
1249 | /* Remove trigger from triggers_ht. */ | |
1250 | trigger_ht_element = caa_container_of(triggers_ht_node, | |
1251 | struct lttng_trigger_ht_element, node); | |
1252 | cds_lfht_del(state->triggers_ht, triggers_ht_node); | |
1253 | ||
1254 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); | |
1255 | lttng_condition_destroy(condition); | |
1256 | action = lttng_trigger_get_action(trigger_ht_element->trigger); | |
1257 | lttng_action_destroy(action); | |
1258 | lttng_trigger_destroy(trigger_ht_element->trigger); | |
1259 | free(trigger_ht_element); | |
1260 | end: | |
1261 | rcu_read_unlock(); | |
1262 | if (_cmd_reply) { | |
1263 | *_cmd_reply = cmd_reply; | |
1264 | } | |
1265 | return 0; | |
1266 | } | |
1267 | ||
1268 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ | |
1269 | int handle_notification_thread_command( | |
1270 | struct notification_thread_handle *handle, | |
1271 | struct notification_thread_state *state) | |
1272 | { | |
1273 | int ret; | |
1274 | uint64_t counter; | |
1275 | struct notification_thread_command *cmd; | |
1276 | ||
1277 | /* Read event_fd to put it back into a quiescent state. */ | |
800c5e10 | 1278 | ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, sizeof(counter)); |
ab0ee2ca JG |
1279 | if (ret == -1) { |
1280 | goto error; | |
1281 | } | |
1282 | ||
1283 | pthread_mutex_lock(&handle->cmd_queue.lock); | |
1284 | cmd = cds_list_first_entry(&handle->cmd_queue.list, | |
1285 | struct notification_thread_command, cmd_list_node); | |
1286 | switch (cmd->type) { | |
1287 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: | |
1288 | DBG("[notification-thread] Received register trigger command"); | |
1289 | ret = handle_notification_thread_command_register_trigger( | |
1290 | state, cmd->parameters.trigger, | |
1291 | &cmd->reply_code); | |
1292 | break; | |
1293 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: | |
1294 | DBG("[notification-thread] Received unregister trigger command"); | |
1295 | ret = handle_notification_thread_command_unregister_trigger( | |
1296 | state, cmd->parameters.trigger, | |
1297 | &cmd->reply_code); | |
1298 | break; | |
1299 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: | |
1300 | DBG("[notification-thread] Received add channel command"); | |
1301 | ret = handle_notification_thread_command_add_channel( | |
1302 | state, &cmd->parameters.add_channel, | |
1303 | &cmd->reply_code); | |
1304 | break; | |
1305 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: | |
1306 | DBG("[notification-thread] Received remove channel command"); | |
1307 | ret = handle_notification_thread_command_remove_channel( | |
1308 | state, cmd->parameters.remove_channel.key, | |
1309 | cmd->parameters.remove_channel.domain, | |
1310 | &cmd->reply_code); | |
1311 | break; | |
1312 | case NOTIFICATION_COMMAND_TYPE_QUIT: | |
1313 | DBG("[notification-thread] Received quit command"); | |
1314 | cmd->reply_code = LTTNG_OK; | |
1315 | ret = 1; | |
1316 | goto end; | |
1317 | default: | |
1318 | ERR("[notification-thread] Unknown internal command received"); | |
1319 | goto error_unlock; | |
1320 | } | |
1321 | ||
1322 | if (ret) { | |
1323 | goto error_unlock; | |
1324 | } | |
1325 | end: | |
1326 | cds_list_del(&cmd->cmd_list_node); | |
8f5e7d40 | 1327 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1328 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1329 | return ret; | |
1330 | error_unlock: | |
1331 | /* Wake-up and return a fatal error to the calling thread. */ | |
8f5e7d40 | 1332 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1333 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1334 | cmd->reply_code = LTTNG_ERR_FATAL; | |
1335 | error: | |
1336 | /* Indicate a fatal error to the caller. */ | |
1337 | return -1; | |
1338 | } | |
1339 | ||
1340 | static | |
1341 | unsigned long hash_client_socket(int socket) | |
1342 | { | |
1343 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); | |
1344 | } | |
1345 | ||
1346 | static | |
1347 | int socket_set_non_blocking(int socket) | |
1348 | { | |
1349 | int ret, flags; | |
1350 | ||
1351 | /* Set the pipe as non-blocking. */ | |
1352 | ret = fcntl(socket, F_GETFL, 0); | |
1353 | if (ret == -1) { | |
1354 | PERROR("fcntl get socket flags"); | |
1355 | goto end; | |
1356 | } | |
1357 | flags = ret; | |
1358 | ||
1359 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); | |
1360 | if (ret == -1) { | |
1361 | PERROR("fcntl set O_NONBLOCK socket flag"); | |
1362 | goto end; | |
1363 | } | |
1364 | DBG("Client socket (fd = %i) set as non-blocking", socket); | |
1365 | end: | |
1366 | return ret; | |
1367 | } | |
1368 | ||
1369 | static | |
b5eb6b46 | 1370 | int client_reset_inbound_state(struct notification_client *client) |
ab0ee2ca JG |
1371 | { |
1372 | int ret; | |
1373 | ||
1374 | ret = lttng_dynamic_buffer_set_size( | |
1375 | &client->communication.inbound.buffer, 0); | |
1376 | assert(!ret); | |
1377 | ||
1378 | client->communication.inbound.bytes_to_receive = | |
1379 | sizeof(struct lttng_notification_channel_message); | |
1380 | client->communication.inbound.msg_type = | |
1381 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; | |
ab0ee2ca JG |
1382 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
1383 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); | |
b5eb6b46 JG |
1384 | ret = lttng_dynamic_buffer_set_size( |
1385 | &client->communication.inbound.buffer, | |
1386 | client->communication.inbound.bytes_to_receive); | |
1387 | return ret; | |
ab0ee2ca JG |
1388 | } |
1389 | ||
1390 | int handle_notification_thread_client_connect( | |
1391 | struct notification_thread_state *state) | |
1392 | { | |
1393 | int ret; | |
1394 | struct notification_client *client; | |
1395 | ||
1396 | DBG("[notification-thread] Handling new notification channel client connection"); | |
1397 | ||
1398 | client = zmalloc(sizeof(*client)); | |
1399 | if (!client) { | |
1400 | /* Fatal error. */ | |
1401 | ret = -1; | |
1402 | goto error; | |
1403 | } | |
1404 | CDS_INIT_LIST_HEAD(&client->condition_list); | |
1405 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); | |
1406 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); | |
f950d02c | 1407 | client->communication.inbound.expect_creds = true; |
b5eb6b46 JG |
1408 | ret = client_reset_inbound_state(client); |
1409 | if (ret) { | |
1410 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1411 | ret = 0; | |
1412 | goto error; | |
1413 | } | |
ab0ee2ca JG |
1414 | |
1415 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); | |
1416 | if (ret < 0) { | |
1417 | ERR("[notification-thread] Failed to accept new notification channel client connection"); | |
1418 | ret = 0; | |
1419 | goto error; | |
1420 | } | |
1421 | ||
1422 | client->socket = ret; | |
1423 | ||
1424 | ret = socket_set_non_blocking(client->socket); | |
1425 | if (ret) { | |
1426 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); | |
1427 | goto error; | |
1428 | } | |
1429 | ||
1430 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); | |
1431 | if (ret < 0) { | |
1432 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); | |
1433 | ret = 0; | |
1434 | goto error; | |
1435 | } | |
1436 | ||
1437 | ret = lttng_poll_add(&state->events, client->socket, | |
1438 | LPOLLIN | LPOLLERR | | |
1439 | LPOLLHUP | LPOLLRDHUP); | |
1440 | if (ret < 0) { | |
1441 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); | |
1442 | ret = 0; | |
1443 | goto error; | |
1444 | } | |
1445 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", | |
1446 | client->socket); | |
1447 | ||
ab0ee2ca JG |
1448 | rcu_read_lock(); |
1449 | cds_lfht_add(state->client_socket_ht, | |
1450 | hash_client_socket(client->socket), | |
1451 | &client->client_socket_ht_node); | |
1452 | rcu_read_unlock(); | |
1453 | ||
1454 | return ret; | |
1455 | error: | |
1456 | notification_client_destroy(client, state); | |
1457 | return ret; | |
1458 | } | |
1459 | ||
1460 | int handle_notification_thread_client_disconnect( | |
1461 | int client_socket, | |
1462 | struct notification_thread_state *state) | |
1463 | { | |
1464 | int ret = 0; | |
1465 | struct notification_client *client; | |
1466 | ||
1467 | rcu_read_lock(); | |
1468 | DBG("[notification-thread] Closing client connection (socket fd = %i)", | |
1469 | client_socket); | |
1470 | client = get_client_from_socket(client_socket, state); | |
1471 | if (!client) { | |
1472 | /* Internal state corruption, fatal error. */ | |
1473 | ERR("[notification-thread] Unable to find client (socket fd = %i)", | |
1474 | client_socket); | |
1475 | ret = -1; | |
1476 | goto end; | |
1477 | } | |
1478 | ||
1479 | ret = lttng_poll_del(&state->events, client_socket); | |
1480 | if (ret) { | |
1481 | ERR("[notification-thread] Failed to remove client socket from poll set"); | |
1482 | } | |
1483 | cds_lfht_del(state->client_socket_ht, | |
1484 | &client->client_socket_ht_node); | |
1485 | notification_client_destroy(client, state); | |
1486 | end: | |
1487 | rcu_read_unlock(); | |
1488 | return ret; | |
1489 | } | |
1490 | ||
1491 | int handle_notification_thread_client_disconnect_all( | |
1492 | struct notification_thread_state *state) | |
1493 | { | |
1494 | struct cds_lfht_iter iter; | |
1495 | struct notification_client *client; | |
1496 | bool error_encoutered = false; | |
1497 | ||
1498 | rcu_read_lock(); | |
1499 | DBG("[notification-thread] Closing all client connections"); | |
1500 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1501 | client_socket_ht_node) { | |
1502 | int ret; | |
1503 | ||
1504 | ret = handle_notification_thread_client_disconnect( | |
1505 | client->socket, state); | |
1506 | if (ret) { | |
1507 | error_encoutered = true; | |
1508 | } | |
1509 | } | |
1510 | rcu_read_unlock(); | |
1511 | return error_encoutered ? 1 : 0; | |
1512 | } | |
1513 | ||
1514 | int handle_notification_thread_trigger_unregister_all( | |
1515 | struct notification_thread_state *state) | |
1516 | { | |
8a9bd316 | 1517 | bool error_occurred = false; |
ab0ee2ca JG |
1518 | struct cds_lfht_iter iter; |
1519 | struct lttng_trigger_ht_element *trigger_ht_element; | |
1520 | ||
1521 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
1522 | node) { | |
1523 | int ret = handle_notification_thread_command_unregister_trigger( | |
1524 | state, trigger_ht_element->trigger, NULL); | |
1525 | if (ret) { | |
8a9bd316 | 1526 | error_occurred = true; |
ab0ee2ca JG |
1527 | } |
1528 | } | |
8a9bd316 | 1529 | return error_occurred ? -1 : 0; |
ab0ee2ca JG |
1530 | } |
1531 | ||
1532 | static | |
1533 | int client_flush_outgoing_queue(struct notification_client *client, | |
1534 | struct notification_thread_state *state) | |
1535 | { | |
1536 | ssize_t ret; | |
1537 | size_t to_send_count; | |
1538 | ||
1539 | assert(client->communication.outbound.buffer.size != 0); | |
1540 | to_send_count = client->communication.outbound.buffer.size; | |
1541 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", | |
1542 | client->socket); | |
1543 | ||
1544 | ret = lttcomm_send_unix_sock_non_block(client->socket, | |
1545 | client->communication.outbound.buffer.data, | |
1546 | to_send_count); | |
1547 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || | |
1548 | (ret > 0 && ret < to_send_count)) { | |
1549 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", | |
1550 | client->socket); | |
1551 | to_send_count -= max(ret, 0); | |
1552 | ||
1553 | memcpy(client->communication.outbound.buffer.data, | |
1554 | client->communication.outbound.buffer.data + | |
1555 | client->communication.outbound.buffer.size - to_send_count, | |
1556 | to_send_count); | |
1557 | ret = lttng_dynamic_buffer_set_size( | |
1558 | &client->communication.outbound.buffer, | |
1559 | to_send_count); | |
1560 | if (ret) { | |
1561 | goto error; | |
1562 | } | |
1563 | ||
1564 | /* | |
1565 | * We want to be notified whenever there is buffer space | |
1566 | * available to send the rest of the payload. | |
1567 | */ | |
1568 | ret = lttng_poll_mod(&state->events, client->socket, | |
1569 | CLIENT_POLL_MASK_IN_OUT); | |
1570 | if (ret) { | |
1571 | goto error; | |
1572 | } | |
1573 | } else if (ret < 0) { | |
1574 | /* Generic error, disconnect the client. */ | |
1575 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", | |
1576 | client->socket); | |
1577 | ret = handle_notification_thread_client_disconnect( | |
1578 | client->socket, state); | |
1579 | if (ret) { | |
1580 | goto error; | |
1581 | } | |
1582 | } else { | |
1583 | /* No error and flushed the queue completely. */ | |
1584 | ret = lttng_dynamic_buffer_set_size( | |
1585 | &client->communication.outbound.buffer, 0); | |
1586 | if (ret) { | |
1587 | goto error; | |
1588 | } | |
1589 | ret = lttng_poll_mod(&state->events, client->socket, | |
1590 | CLIENT_POLL_MASK_IN); | |
1591 | if (ret) { | |
1592 | goto error; | |
1593 | } | |
1594 | ||
1595 | client->communication.outbound.queued_command_reply = false; | |
1596 | client->communication.outbound.dropped_notification = false; | |
1597 | } | |
1598 | ||
1599 | return 0; | |
1600 | error: | |
1601 | return -1; | |
1602 | } | |
1603 | ||
1604 | static | |
1605 | int client_send_command_reply(struct notification_client *client, | |
1606 | struct notification_thread_state *state, | |
1607 | enum lttng_notification_channel_status status) | |
1608 | { | |
1609 | int ret; | |
1610 | struct lttng_notification_channel_command_reply reply = { | |
1611 | .status = (int8_t) status, | |
1612 | }; | |
1613 | struct lttng_notification_channel_message msg = { | |
1614 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, | |
1615 | .size = sizeof(reply), | |
1616 | }; | |
1617 | char buffer[sizeof(msg) + sizeof(reply)]; | |
1618 | ||
1619 | if (client->communication.outbound.queued_command_reply) { | |
1620 | /* Protocol error. */ | |
1621 | goto error; | |
1622 | } | |
1623 | ||
1624 | memcpy(buffer, &msg, sizeof(msg)); | |
1625 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); | |
1626 | DBG("[notification-thread] Send command reply (%i)", (int) status); | |
1627 | ||
1628 | /* Enqueue buffer to outgoing queue and flush it. */ | |
1629 | ret = lttng_dynamic_buffer_append( | |
1630 | &client->communication.outbound.buffer, | |
1631 | buffer, sizeof(buffer)); | |
1632 | if (ret) { | |
1633 | goto error; | |
1634 | } | |
1635 | ||
1636 | ret = client_flush_outgoing_queue(client, state); | |
1637 | if (ret) { | |
1638 | goto error; | |
1639 | } | |
1640 | ||
1641 | if (client->communication.outbound.buffer.size != 0) { | |
1642 | /* Queue could not be emptied. */ | |
1643 | client->communication.outbound.queued_command_reply = true; | |
1644 | } | |
1645 | ||
1646 | return 0; | |
1647 | error: | |
1648 | return -1; | |
1649 | } | |
1650 | ||
1651 | static | |
1652 | int client_dispatch_message(struct notification_client *client, | |
1653 | struct notification_thread_state *state) | |
1654 | { | |
1655 | int ret = 0; | |
1656 | ||
1657 | if (client->communication.inbound.msg_type != | |
1658 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && | |
1659 | client->communication.inbound.msg_type != | |
1660 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && | |
1661 | !client->validated) { | |
1662 | WARN("[notification-thread] client attempted a command before handshake"); | |
1663 | ret = -1; | |
1664 | goto end; | |
1665 | } | |
1666 | ||
1667 | switch (client->communication.inbound.msg_type) { | |
1668 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: | |
1669 | { | |
1670 | /* | |
1671 | * Receiving message header. The function will be called again | |
1672 | * once the rest of the message as been received and can be | |
1673 | * interpreted. | |
1674 | */ | |
1675 | const struct lttng_notification_channel_message *msg; | |
1676 | ||
1677 | assert(sizeof(*msg) == | |
1678 | client->communication.inbound.buffer.size); | |
1679 | msg = (const struct lttng_notification_channel_message *) | |
1680 | client->communication.inbound.buffer.data; | |
1681 | ||
1682 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
1683 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); | |
1684 | ret = -1; | |
1685 | goto end; | |
1686 | } | |
1687 | ||
1688 | switch (msg->type) { | |
1689 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
1690 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
1691 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1692 | break; | |
1693 | default: | |
1694 | ret = -1; | |
1695 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); | |
1696 | goto end; | |
1697 | } | |
1698 | ||
1699 | client->communication.inbound.bytes_to_receive = msg->size; | |
1700 | client->communication.inbound.msg_type = | |
1701 | (enum lttng_notification_channel_message_type) msg->type; | |
ab0ee2ca | 1702 | ret = lttng_dynamic_buffer_set_size( |
b5eb6b46 | 1703 | &client->communication.inbound.buffer, msg->size); |
ab0ee2ca JG |
1704 | if (ret) { |
1705 | goto end; | |
1706 | } | |
1707 | break; | |
1708 | } | |
1709 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1710 | { | |
1711 | struct lttng_notification_channel_command_handshake *handshake_client; | |
1712 | struct lttng_notification_channel_command_handshake handshake_reply = { | |
1713 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
1714 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
1715 | }; | |
1716 | struct lttng_notification_channel_message msg_header = { | |
1717 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
1718 | .size = sizeof(handshake_reply), | |
1719 | }; | |
1720 | enum lttng_notification_channel_status status = | |
1721 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
1722 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; | |
1723 | ||
1724 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
1725 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, | |
1726 | sizeof(handshake_reply)); | |
1727 | ||
1728 | handshake_client = | |
1729 | (struct lttng_notification_channel_command_handshake *) | |
1730 | client->communication.inbound.buffer.data; | |
b8165ded | 1731 | client->major = handshake_client->major; |
ab0ee2ca JG |
1732 | client->minor = handshake_client->minor; |
1733 | if (!client->communication.inbound.creds_received) { | |
1734 | ERR("[notification-thread] No credentials received from client"); | |
1735 | ret = -1; | |
1736 | goto end; | |
1737 | } | |
1738 | ||
1739 | client->uid = LTTNG_SOCK_GET_UID_CRED( | |
1740 | &client->communication.inbound.creds); | |
1741 | client->gid = LTTNG_SOCK_GET_GID_CRED( | |
1742 | &client->communication.inbound.creds); | |
1743 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", | |
1744 | client->uid, client->gid, (int) client->major, | |
1745 | (int) client->minor); | |
1746 | ||
1747 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
1748 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; | |
1749 | } | |
1750 | ||
1751 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, | |
1752 | send_buffer, sizeof(send_buffer)); | |
1753 | if (ret) { | |
1754 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); | |
1755 | goto end; | |
1756 | } | |
1757 | ||
1758 | ret = client_flush_outgoing_queue(client, state); | |
1759 | if (ret) { | |
1760 | goto end; | |
1761 | } | |
1762 | ||
1763 | ret = client_send_command_reply(client, state, status); | |
1764 | if (ret) { | |
1765 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
1766 | goto end; | |
1767 | } | |
1768 | ||
1769 | /* Set reception state to receive the next message header. */ | |
b5eb6b46 JG |
1770 | ret = client_reset_inbound_state(client); |
1771 | if (ret) { | |
1772 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1773 | goto end; | |
1774 | } | |
ab0ee2ca JG |
1775 | client->validated = true; |
1776 | break; | |
1777 | } | |
1778 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
1779 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
1780 | { | |
1781 | struct lttng_condition *condition; | |
1782 | enum lttng_notification_channel_status status = | |
1783 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
1784 | const struct lttng_buffer_view condition_view = | |
1785 | lttng_buffer_view_from_dynamic_buffer( | |
1786 | &client->communication.inbound.buffer, | |
1787 | 0, -1); | |
1788 | size_t expected_condition_size = | |
1789 | client->communication.inbound.buffer.size; | |
1790 | ||
1791 | ret = lttng_condition_create_from_buffer(&condition_view, | |
1792 | &condition); | |
1793 | if (ret != expected_condition_size) { | |
1794 | ERR("[notification-thread] Malformed condition received from client"); | |
1795 | goto end; | |
1796 | } | |
1797 | ||
1798 | if (client->communication.inbound.msg_type == | |
1799 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { | |
1800 | /* | |
1801 | * FIXME The current state should be evaluated on | |
1802 | * subscription. | |
1803 | */ | |
1804 | ret = notification_thread_client_subscribe(client, | |
1805 | condition, state, &status); | |
1806 | } else { | |
1807 | ret = notification_thread_client_unsubscribe(client, | |
1808 | condition, state, &status); | |
1809 | } | |
1810 | if (ret) { | |
1811 | goto end; | |
1812 | } | |
1813 | ||
1814 | ret = client_send_command_reply(client, state, status); | |
1815 | if (ret) { | |
1816 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
1817 | goto end; | |
1818 | } | |
1819 | ||
1820 | /* Set reception state to receive the next message header. */ | |
b5eb6b46 JG |
1821 | ret = client_reset_inbound_state(client); |
1822 | if (ret) { | |
1823 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1824 | goto end; | |
1825 | } | |
ab0ee2ca JG |
1826 | break; |
1827 | } | |
1828 | default: | |
1829 | abort(); | |
1830 | } | |
1831 | end: | |
1832 | return ret; | |
1833 | } | |
1834 | ||
1835 | /* Incoming data from client. */ | |
1836 | int handle_notification_thread_client_in( | |
1837 | struct notification_thread_state *state, int socket) | |
1838 | { | |
b5eb6b46 | 1839 | int ret = 0; |
ab0ee2ca JG |
1840 | struct notification_client *client; |
1841 | ssize_t recv_ret; | |
1842 | size_t offset; | |
1843 | ||
1844 | client = get_client_from_socket(socket, state); | |
1845 | if (!client) { | |
1846 | /* Internal error, abort. */ | |
1847 | ret = -1; | |
1848 | goto end; | |
1849 | } | |
1850 | ||
b5eb6b46 JG |
1851 | offset = client->communication.inbound.buffer.size - |
1852 | client->communication.inbound.bytes_to_receive; | |
f950d02c | 1853 | if (client->communication.inbound.expect_creds) { |
ab0ee2ca JG |
1854 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
1855 | client->communication.inbound.buffer.data + offset, | |
1856 | client->communication.inbound.bytes_to_receive, | |
1857 | &client->communication.inbound.creds); | |
1858 | if (recv_ret > 0) { | |
f950d02c | 1859 | client->communication.inbound.expect_creds = false; |
ab0ee2ca JG |
1860 | client->communication.inbound.creds_received = true; |
1861 | } | |
1862 | } else { | |
1863 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, | |
1864 | client->communication.inbound.buffer.data + offset, | |
1865 | client->communication.inbound.bytes_to_receive); | |
1866 | } | |
1867 | if (recv_ret < 0) { | |
1868 | goto error_disconnect_client; | |
1869 | } | |
1870 | ||
1871 | client->communication.inbound.bytes_to_receive -= recv_ret; | |
ab0ee2ca JG |
1872 | if (client->communication.inbound.bytes_to_receive == 0) { |
1873 | ret = client_dispatch_message(client, state); | |
1874 | if (ret) { | |
1875 | /* | |
1876 | * Only returns an error if this client must be | |
1877 | * disconnected. | |
1878 | */ | |
1879 | goto error_disconnect_client; | |
1880 | } | |
1881 | } else { | |
1882 | goto end; | |
1883 | } | |
1884 | end: | |
1885 | return ret; | |
1886 | error_disconnect_client: | |
1887 | ret = handle_notification_thread_client_disconnect(socket, state); | |
1888 | return ret; | |
1889 | } | |
1890 | ||
1891 | /* Client ready to receive outgoing data. */ | |
1892 | int handle_notification_thread_client_out( | |
1893 | struct notification_thread_state *state, int socket) | |
1894 | { | |
1895 | int ret; | |
1896 | struct notification_client *client; | |
1897 | ||
1898 | client = get_client_from_socket(socket, state); | |
1899 | if (!client) { | |
1900 | /* Internal error, abort. */ | |
1901 | ret = -1; | |
1902 | goto end; | |
1903 | } | |
1904 | ||
1905 | ret = client_flush_outgoing_queue(client, state); | |
1906 | if (ret) { | |
1907 | goto end; | |
1908 | } | |
1909 | end: | |
1910 | return ret; | |
1911 | } | |
1912 | ||
1913 | static | |
1914 | bool evaluate_buffer_usage_condition(struct lttng_condition *condition, | |
1915 | struct channel_state_sample *sample, uint64_t buffer_capacity) | |
1916 | { | |
1917 | bool result = false; | |
1918 | uint64_t threshold; | |
1919 | enum lttng_condition_type condition_type; | |
1920 | struct lttng_condition_buffer_usage *use_condition = container_of( | |
1921 | condition, struct lttng_condition_buffer_usage, | |
1922 | parent); | |
1923 | ||
1924 | if (!sample) { | |
1925 | goto end; | |
1926 | } | |
1927 | ||
1928 | if (use_condition->threshold_bytes.set) { | |
1929 | threshold = use_condition->threshold_bytes.value; | |
1930 | } else { | |
1931 | /* | |
1932 | * Threshold was expressed as a ratio. | |
1933 | * | |
1934 | * TODO the threshold (in bytes) of conditions expressed | |
1935 | * as a ratio of total buffer size could be cached to | |
1936 | * forego this double-multiplication or it could be performed | |
1937 | * as fixed-point math. | |
1938 | * | |
1939 | * Note that caching should accomodate the case where the | |
1940 | * condition applies to multiple channels (i.e. don't assume | |
1941 | * that all channels matching my_chann* have the same size...) | |
1942 | */ | |
1943 | threshold = (uint64_t) (use_condition->threshold_ratio.value * | |
1944 | (double) buffer_capacity); | |
1945 | } | |
1946 | ||
1947 | condition_type = lttng_condition_get_type(condition); | |
1948 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { | |
1949 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
1950 | threshold, sample->highest_usage); | |
1951 | ||
1952 | /* | |
1953 | * The low condition should only be triggered once _all_ of the | |
1954 | * streams in a channel have gone below the "low" threshold. | |
1955 | */ | |
1956 | if (sample->highest_usage <= threshold) { | |
1957 | result = true; | |
1958 | } | |
1959 | } else { | |
1960 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
1961 | threshold, sample->highest_usage); | |
1962 | ||
1963 | /* | |
1964 | * For high buffer usage scenarios, we want to trigger whenever | |
1965 | * _any_ of the streams has reached the "high" threshold. | |
1966 | */ | |
1967 | if (sample->highest_usage >= threshold) { | |
1968 | result = true; | |
1969 | } | |
1970 | } | |
1971 | end: | |
1972 | return result; | |
1973 | } | |
1974 | ||
1975 | static | |
1976 | int evaluate_condition(struct lttng_condition *condition, | |
1977 | struct lttng_evaluation **evaluation, | |
1978 | struct notification_thread_state *state, | |
1979 | struct channel_state_sample *previous_sample, | |
1980 | struct channel_state_sample *latest_sample, | |
1981 | uint64_t buffer_capacity) | |
1982 | { | |
1983 | int ret = 0; | |
1984 | enum lttng_condition_type condition_type; | |
1985 | bool previous_sample_result; | |
1986 | bool latest_sample_result; | |
1987 | ||
1988 | condition_type = lttng_condition_get_type(condition); | |
1989 | /* No other condition type supported for the moment. */ | |
1990 | assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || | |
1991 | condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); | |
1992 | ||
1993 | previous_sample_result = evaluate_buffer_usage_condition(condition, | |
1994 | previous_sample, buffer_capacity); | |
1995 | latest_sample_result = evaluate_buffer_usage_condition(condition, | |
1996 | latest_sample, buffer_capacity); | |
1997 | ||
1998 | if (!latest_sample_result || | |
1999 | (previous_sample_result == latest_sample_result)) { | |
2000 | /* | |
2001 | * Only trigger on a condition evaluation transition. | |
2002 | * | |
2003 | * NOTE: This edge-triggered logic may not be appropriate for | |
2004 | * future condition types. | |
2005 | */ | |
2006 | goto end; | |
2007 | } | |
2008 | ||
2009 | if (evaluation && latest_sample_result) { | |
2010 | *evaluation = lttng_evaluation_buffer_usage_create( | |
2011 | condition_type, | |
2012 | latest_sample->highest_usage, | |
2013 | buffer_capacity); | |
2014 | if (!*evaluation) { | |
2015 | ret = -1; | |
2016 | goto end; | |
2017 | } | |
2018 | } | |
2019 | end: | |
2020 | return ret; | |
2021 | } | |
2022 | ||
2023 | static | |
2024 | int client_enqueue_dropped_notification(struct notification_client *client, | |
2025 | struct notification_thread_state *state) | |
2026 | { | |
2027 | int ret; | |
2028 | struct lttng_notification_channel_message msg = { | |
2029 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, | |
2030 | .size = 0, | |
2031 | }; | |
2032 | ||
2033 | ret = lttng_dynamic_buffer_append( | |
2034 | &client->communication.outbound.buffer, &msg, | |
2035 | sizeof(msg)); | |
2036 | return ret; | |
2037 | } | |
2038 | ||
2039 | static | |
2040 | int send_evaluation_to_clients(struct lttng_trigger *trigger, | |
2041 | struct lttng_evaluation *evaluation, | |
2042 | struct notification_client_list* client_list, | |
2043 | struct notification_thread_state *state, | |
2044 | uid_t channel_uid, gid_t channel_gid) | |
2045 | { | |
2046 | int ret = 0; | |
2047 | struct lttng_dynamic_buffer msg_buffer; | |
2048 | struct notification_client_list_element *client_list_element, *tmp; | |
2049 | struct lttng_notification *notification; | |
2050 | struct lttng_condition *condition; | |
2051 | ssize_t expected_notification_size, notification_size; | |
2052 | struct lttng_notification_channel_message msg; | |
2053 | ||
2054 | lttng_dynamic_buffer_init(&msg_buffer); | |
2055 | ||
2056 | condition = lttng_trigger_get_condition(trigger); | |
2057 | assert(condition); | |
2058 | ||
2059 | notification = lttng_notification_create(condition, evaluation); | |
2060 | if (!notification) { | |
2061 | ret = -1; | |
2062 | goto end; | |
2063 | } | |
2064 | ||
2065 | expected_notification_size = lttng_notification_serialize(notification, | |
2066 | NULL); | |
2067 | if (expected_notification_size < 0) { | |
2068 | ERR("[notification-thread] Failed to get size of serialized notification"); | |
2069 | ret = -1; | |
2070 | goto end; | |
2071 | } | |
2072 | ||
2073 | msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; | |
2074 | msg.size = (uint32_t) expected_notification_size; | |
2075 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); | |
2076 | if (ret) { | |
2077 | goto end; | |
2078 | } | |
2079 | ||
2080 | ret = lttng_dynamic_buffer_set_size(&msg_buffer, | |
2081 | msg_buffer.size + expected_notification_size); | |
2082 | if (ret) { | |
2083 | goto end; | |
2084 | } | |
2085 | ||
2086 | notification_size = lttng_notification_serialize(notification, | |
2087 | msg_buffer.data + sizeof(msg)); | |
2088 | if (notification_size != expected_notification_size) { | |
2089 | ERR("[notification-thread] Failed to serialize notification"); | |
2090 | ret = -1; | |
2091 | goto end; | |
2092 | } | |
2093 | ||
2094 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
2095 | &client_list->list, node) { | |
2096 | struct notification_client *client = | |
2097 | client_list_element->client; | |
2098 | ||
2099 | if (client->uid != channel_uid && client->gid != channel_gid && | |
2100 | client->uid != 0) { | |
2101 | /* Client is not allowed to monitor this channel. */ | |
2102 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); | |
2103 | continue; | |
2104 | } | |
2105 | ||
2106 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", | |
2107 | client->socket, msg_buffer.size); | |
2108 | if (client->communication.outbound.buffer.size) { | |
2109 | /* | |
2110 | * Outgoing data is already buffered for this client; | |
2111 | * drop the notification and enqueue a "dropped | |
2112 | * notification" message if this is the first dropped | |
2113 | * notification since the socket spilled-over to the | |
2114 | * queue. | |
2115 | */ | |
2116 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", | |
2117 | client->socket); | |
2118 | if (!client->communication.outbound.dropped_notification) { | |
2119 | client->communication.outbound.dropped_notification = true; | |
2120 | ret = client_enqueue_dropped_notification( | |
2121 | client, state); | |
2122 | if (ret) { | |
2123 | goto end; | |
2124 | } | |
2125 | } | |
2126 | continue; | |
2127 | } | |
2128 | ||
2129 | ret = lttng_dynamic_buffer_append_buffer( | |
2130 | &client->communication.outbound.buffer, | |
2131 | &msg_buffer); | |
2132 | if (ret) { | |
2133 | goto end; | |
2134 | } | |
2135 | ||
2136 | ret = client_flush_outgoing_queue(client, state); | |
2137 | if (ret) { | |
2138 | goto end; | |
2139 | } | |
2140 | } | |
2141 | ret = 0; | |
2142 | end: | |
2143 | lttng_notification_destroy(notification); | |
2144 | lttng_dynamic_buffer_reset(&msg_buffer); | |
2145 | return ret; | |
2146 | } | |
2147 | ||
2148 | int handle_notification_thread_channel_sample( | |
2149 | struct notification_thread_state *state, int pipe, | |
2150 | enum lttng_domain_type domain) | |
2151 | { | |
2152 | int ret = 0; | |
2153 | struct lttcomm_consumer_channel_monitor_msg sample_msg; | |
2154 | struct channel_state_sample previous_sample, latest_sample; | |
2155 | struct channel_info *channel_info; | |
2156 | struct cds_lfht_node *node; | |
2157 | struct cds_lfht_iter iter; | |
2158 | struct lttng_channel_trigger_list *trigger_list; | |
2159 | struct lttng_trigger_list_element *trigger_list_element; | |
2160 | bool previous_sample_available = false; | |
2161 | ||
2162 | /* | |
2163 | * The monitoring pipe only holds messages smaller than PIPE_BUF, | |
2164 | * ensuring that read/write of sampling messages are atomic. | |
2165 | */ | |
8af8a558 | 2166 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
ab0ee2ca JG |
2167 | if (ret != sizeof(sample_msg)) { |
2168 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", | |
2169 | pipe); | |
2170 | ret = -1; | |
2171 | goto end; | |
2172 | } | |
2173 | ||
2174 | ret = 0; | |
2175 | latest_sample.key.key = sample_msg.key; | |
2176 | latest_sample.key.domain = domain; | |
2177 | latest_sample.highest_usage = sample_msg.highest; | |
2178 | latest_sample.lowest_usage = sample_msg.lowest; | |
2179 | ||
2180 | rcu_read_lock(); | |
2181 | ||
2182 | /* Retrieve the channel's informations */ | |
2183 | cds_lfht_lookup(state->channels_ht, | |
2184 | hash_channel_key(&latest_sample.key), | |
2185 | match_channel_info, | |
2186 | &latest_sample.key, | |
2187 | &iter); | |
2188 | node = cds_lfht_iter_get_node(&iter); | |
2189 | if (!node) { | |
2190 | /* | |
2191 | * Not an error since the consumer can push a sample to the pipe | |
2192 | * and the rest of the session daemon could notify us of the | |
2193 | * channel's destruction before we get a chance to process that | |
2194 | * sample. | |
2195 | */ | |
2196 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", | |
2197 | latest_sample.key.key, | |
2198 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : | |
2199 | "user space"); | |
2200 | goto end_unlock; | |
2201 | } | |
2202 | channel_info = caa_container_of(node, struct channel_info, | |
2203 | channels_ht_node); | |
2204 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64")", | |
2205 | channel_info->channel_name, | |
2206 | latest_sample.key.key, | |
2207 | channel_info->session_name, | |
2208 | latest_sample.highest_usage, | |
2209 | latest_sample.lowest_usage); | |
2210 | ||
2211 | /* Retrieve the channel's last sample, if it exists, and update it. */ | |
2212 | cds_lfht_lookup(state->channel_state_ht, | |
2213 | hash_channel_key(&latest_sample.key), | |
2214 | match_channel_state_sample, | |
2215 | &latest_sample.key, | |
2216 | &iter); | |
2217 | node = cds_lfht_iter_get_node(&iter); | |
2218 | if (node) { | |
2219 | struct channel_state_sample *stored_sample; | |
2220 | ||
2221 | /* Update the sample stored. */ | |
2222 | stored_sample = caa_container_of(node, | |
2223 | struct channel_state_sample, | |
2224 | channel_state_ht_node); | |
2225 | memcpy(&previous_sample, stored_sample, | |
2226 | sizeof(previous_sample)); | |
2227 | stored_sample->highest_usage = latest_sample.highest_usage; | |
2228 | stored_sample->lowest_usage = latest_sample.lowest_usage; | |
2229 | previous_sample_available = true; | |
2230 | } else { | |
2231 | /* | |
2232 | * This is the channel's first sample, allocate space for and | |
2233 | * store the new sample. | |
2234 | */ | |
2235 | struct channel_state_sample *stored_sample; | |
2236 | ||
2237 | stored_sample = zmalloc(sizeof(*stored_sample)); | |
2238 | if (!stored_sample) { | |
2239 | ret = -1; | |
2240 | goto end_unlock; | |
2241 | } | |
2242 | ||
2243 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); | |
2244 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); | |
2245 | cds_lfht_add(state->channel_state_ht, | |
2246 | hash_channel_key(&stored_sample->key), | |
2247 | &stored_sample->channel_state_ht_node); | |
2248 | } | |
2249 | ||
2250 | /* Find triggers associated with this channel. */ | |
2251 | cds_lfht_lookup(state->channel_triggers_ht, | |
2252 | hash_channel_key(&latest_sample.key), | |
2253 | match_channel_trigger_list, | |
2254 | &latest_sample.key, | |
2255 | &iter); | |
2256 | node = cds_lfht_iter_get_node(&iter); | |
2257 | if (!node) { | |
2258 | goto end_unlock; | |
2259 | } | |
2260 | ||
2261 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
2262 | channel_triggers_ht_node); | |
2263 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, | |
2264 | node) { | |
2265 | struct lttng_condition *condition; | |
2266 | struct lttng_action *action; | |
2267 | struct lttng_trigger *trigger; | |
2268 | struct notification_client_list *client_list; | |
2269 | struct lttng_evaluation *evaluation = NULL; | |
2270 | ||
2271 | trigger = trigger_list_element->trigger; | |
2272 | condition = lttng_trigger_get_condition(trigger); | |
2273 | assert(condition); | |
2274 | action = lttng_trigger_get_action(trigger); | |
2275 | ||
2276 | /* Notify actions are the only type currently supported. */ | |
2277 | assert(lttng_action_get_type(action) == | |
2278 | LTTNG_ACTION_TYPE_NOTIFY); | |
2279 | ||
2280 | /* | |
2281 | * Check if any client is subscribed to the result of this | |
2282 | * evaluation. | |
2283 | */ | |
2284 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
2285 | lttng_condition_hash(condition), | |
2286 | match_client_list, | |
2287 | trigger, | |
2288 | &iter); | |
2289 | node = cds_lfht_iter_get_node(&iter); | |
2290 | assert(node); | |
2291 | ||
2292 | client_list = caa_container_of(node, | |
2293 | struct notification_client_list, | |
2294 | notification_trigger_ht_node); | |
2295 | if (cds_list_empty(&client_list->list)) { | |
2296 | /* | |
2297 | * No clients interested in the evaluation's result, | |
2298 | * skip it. | |
2299 | */ | |
2300 | continue; | |
2301 | } | |
2302 | ||
2303 | ret = evaluate_condition(condition, &evaluation, state, | |
2304 | previous_sample_available ? &previous_sample : NULL, | |
2305 | &latest_sample, channel_info->capacity); | |
2306 | if (ret) { | |
2307 | goto end_unlock; | |
2308 | } | |
2309 | ||
2310 | if (!evaluation) { | |
2311 | continue; | |
2312 | } | |
2313 | ||
2314 | /* Dispatch evaluation result to all clients. */ | |
2315 | ret = send_evaluation_to_clients(trigger_list_element->trigger, | |
2316 | evaluation, client_list, state, | |
2317 | channel_info->uid, channel_info->gid); | |
2318 | if (ret) { | |
2319 | goto end_unlock; | |
2320 | } | |
2321 | } | |
2322 | end_unlock: | |
2323 | rcu_read_unlock(); | |
2324 | end: | |
2325 | return ret; | |
2326 | } |