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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> | |
1da26331 | 36 | |
ab0ee2ca JG |
37 | #include <time.h> |
38 | #include <unistd.h> | |
39 | #include <assert.h> | |
40 | #include <inttypes.h> | |
d53ea4e4 | 41 | #include <fcntl.h> |
ab0ee2ca | 42 | |
1da26331 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 | /* | |
5332364f | 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 { | |
14fa22f8 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 | */ | |
01ea340e | 118 | bool expect_creds; |
ab0ee2ca JG |
119 | /* |
120 | * Indicates whether or not credentials were received | |
121 | * from the client. | |
122 | */ | |
123 | bool creds_received; | |
14fa22f8 | 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 | ||
e4db5ace 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); | |
6633b0dd | 298 | } else if (condition->threshold_bytes.set) { |
ab0ee2ca JG |
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 | ||
e4db5ace 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 | ||
e4db5ace 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, | |
2ae99f0b | 419 | current_condition)) { |
e4db5ace JR |
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) { | |
066a3c82 | 472 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
e4db5ace 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) { | |
2ae99f0b JG |
558 | /* |
559 | * No notification-emiting trigger registered with this | |
560 | * condition. We don't evaluate the condition right away | |
561 | * since this trigger is not registered yet. | |
562 | */ | |
4fb43b68 | 563 | free(client_list_element); |
ab0ee2ca JG |
564 | goto end_unlock; |
565 | } | |
566 | ||
567 | client_list = caa_container_of(node, struct notification_client_list, | |
568 | notification_trigger_ht_node); | |
2ae99f0b JG |
569 | /* |
570 | * The condition to which the client just subscribed is evaluated | |
571 | * at this point so that conditions that are already TRUE result | |
572 | * in a notification being sent out. | |
573 | */ | |
e4db5ace JR |
574 | if (evaluate_condition_for_client(client_list->trigger, condition, |
575 | client, state)) { | |
576 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); | |
577 | ret = -1; | |
578 | goto end_unlock; | |
579 | } | |
580 | ||
581 | /* | |
582 | * Add the client to the list of clients interested in a given trigger | |
583 | * if a "notification" trigger with a corresponding condition was | |
584 | * added prior. | |
585 | */ | |
ab0ee2ca JG |
586 | client_list_element->client = client; |
587 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
588 | cds_list_add(&client_list_element->node, &client_list->list); | |
589 | end_unlock: | |
590 | rcu_read_unlock(); | |
591 | end: | |
592 | if (_status) { | |
593 | *_status = status; | |
594 | } | |
595 | return ret; | |
596 | error: | |
597 | free(condition_list_element); | |
598 | free(client_list_element); | |
599 | return ret; | |
600 | } | |
601 | ||
602 | static | |
603 | int notification_thread_client_unsubscribe( | |
604 | struct notification_client *client, | |
605 | struct lttng_condition *condition, | |
606 | struct notification_thread_state *state, | |
607 | enum lttng_notification_channel_status *_status) | |
608 | { | |
609 | struct cds_lfht_iter iter; | |
610 | struct cds_lfht_node *node; | |
611 | struct notification_client_list *client_list; | |
612 | struct lttng_condition_list_element *condition_list_element, | |
613 | *condition_tmp; | |
614 | struct notification_client_list_element *client_list_element, | |
615 | *client_tmp; | |
616 | bool condition_found = false; | |
617 | enum lttng_notification_channel_status status = | |
618 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
619 | ||
620 | /* Remove the condition from the client's condition list. */ | |
621 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, | |
622 | &client->condition_list, node) { | |
623 | if (!lttng_condition_is_equal(condition_list_element->condition, | |
624 | condition)) { | |
625 | continue; | |
626 | } | |
627 | ||
628 | cds_list_del(&condition_list_element->node); | |
629 | /* | |
630 | * The caller may be iterating on the client's conditions to | |
631 | * tear down a client's connection. In this case, the condition | |
632 | * will be destroyed at the end. | |
633 | */ | |
634 | if (condition != condition_list_element->condition) { | |
635 | lttng_condition_destroy( | |
636 | condition_list_element->condition); | |
637 | } | |
638 | free(condition_list_element); | |
639 | condition_found = true; | |
640 | break; | |
641 | } | |
642 | ||
643 | if (!condition_found) { | |
644 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; | |
645 | goto end; | |
646 | } | |
647 | ||
648 | /* | |
649 | * Remove the client from the list of clients interested the trigger | |
650 | * matching the condition. | |
651 | */ | |
652 | rcu_read_lock(); | |
653 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
654 | lttng_condition_hash(condition), | |
655 | match_client_list_condition, | |
656 | condition, | |
657 | &iter); | |
658 | node = cds_lfht_iter_get_node(&iter); | |
659 | if (!node) { | |
660 | goto end_unlock; | |
661 | } | |
662 | ||
663 | client_list = caa_container_of(node, struct notification_client_list, | |
664 | notification_trigger_ht_node); | |
665 | cds_list_for_each_entry_safe(client_list_element, client_tmp, | |
666 | &client_list->list, node) { | |
667 | if (client_list_element->client->socket != client->socket) { | |
668 | continue; | |
669 | } | |
670 | cds_list_del(&client_list_element->node); | |
671 | free(client_list_element); | |
672 | break; | |
673 | } | |
674 | end_unlock: | |
675 | rcu_read_unlock(); | |
676 | end: | |
677 | lttng_condition_destroy(condition); | |
678 | if (_status) { | |
679 | *_status = status; | |
680 | } | |
681 | return 0; | |
682 | } | |
683 | ||
684 | static | |
685 | void notification_client_destroy(struct notification_client *client, | |
686 | struct notification_thread_state *state) | |
687 | { | |
688 | struct lttng_condition_list_element *condition_list_element, *tmp; | |
689 | ||
690 | if (!client) { | |
691 | return; | |
692 | } | |
693 | ||
694 | /* Release all conditions to which the client was subscribed. */ | |
695 | cds_list_for_each_entry_safe(condition_list_element, tmp, | |
696 | &client->condition_list, node) { | |
697 | (void) notification_thread_client_unsubscribe(client, | |
698 | condition_list_element->condition, state, NULL); | |
699 | } | |
700 | ||
701 | if (client->socket >= 0) { | |
702 | (void) lttcomm_close_unix_sock(client->socket); | |
703 | } | |
704 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); | |
705 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); | |
706 | free(client); | |
707 | } | |
708 | ||
709 | /* | |
710 | * Call with rcu_read_lock held (and hold for the lifetime of the returned | |
711 | * client pointer). | |
712 | */ | |
713 | static | |
714 | struct notification_client *get_client_from_socket(int socket, | |
715 | struct notification_thread_state *state) | |
716 | { | |
717 | struct cds_lfht_iter iter; | |
718 | struct cds_lfht_node *node; | |
719 | struct notification_client *client = NULL; | |
720 | ||
721 | cds_lfht_lookup(state->client_socket_ht, | |
722 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), | |
723 | match_client, | |
724 | (void *) (unsigned long) socket, | |
725 | &iter); | |
726 | node = cds_lfht_iter_get_node(&iter); | |
727 | if (!node) { | |
728 | goto end; | |
729 | } | |
730 | ||
731 | client = caa_container_of(node, struct notification_client, | |
732 | client_socket_ht_node); | |
733 | end: | |
734 | return client; | |
735 | } | |
736 | ||
737 | static | |
738 | bool trigger_applies_to_channel(struct lttng_trigger *trigger, | |
739 | struct channel_info *info) | |
740 | { | |
741 | enum lttng_condition_status status; | |
742 | struct lttng_condition *condition; | |
743 | const char *trigger_session_name = NULL; | |
744 | const char *trigger_channel_name = NULL; | |
745 | enum lttng_domain_type trigger_domain; | |
746 | ||
747 | condition = lttng_trigger_get_condition(trigger); | |
748 | if (!condition) { | |
749 | goto fail; | |
750 | } | |
751 | ||
752 | switch (lttng_condition_get_type(condition)) { | |
753 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
754 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
755 | break; | |
756 | default: | |
757 | goto fail; | |
758 | } | |
759 | ||
760 | status = lttng_condition_buffer_usage_get_domain_type(condition, | |
761 | &trigger_domain); | |
762 | assert(status == LTTNG_CONDITION_STATUS_OK); | |
763 | if (info->key.domain != trigger_domain) { | |
764 | goto fail; | |
765 | } | |
766 | ||
767 | status = lttng_condition_buffer_usage_get_session_name( | |
768 | condition, &trigger_session_name); | |
769 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_session_name); | |
770 | ||
771 | status = lttng_condition_buffer_usage_get_channel_name( | |
772 | condition, &trigger_channel_name); | |
773 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); | |
774 | ||
775 | if (strcmp(info->session_name, trigger_session_name)) { | |
776 | goto fail; | |
777 | } | |
778 | if (strcmp(info->channel_name, trigger_channel_name)) { | |
779 | goto fail; | |
780 | } | |
781 | ||
782 | return true; | |
783 | fail: | |
784 | return false; | |
785 | } | |
786 | ||
787 | static | |
788 | bool trigger_applies_to_client(struct lttng_trigger *trigger, | |
789 | struct notification_client *client) | |
790 | { | |
791 | bool applies = false; | |
792 | struct lttng_condition_list_element *condition_list_element; | |
793 | ||
794 | cds_list_for_each_entry(condition_list_element, &client->condition_list, | |
795 | node) { | |
796 | applies = lttng_condition_is_equal( | |
797 | condition_list_element->condition, | |
798 | lttng_trigger_get_condition(trigger)); | |
799 | if (applies) { | |
800 | break; | |
801 | } | |
802 | } | |
803 | return applies; | |
804 | } | |
805 | ||
ab0ee2ca JG |
806 | static |
807 | int handle_notification_thread_command_add_channel( | |
808 | struct notification_thread_state *state, | |
809 | struct channel_info *channel_info, | |
810 | enum lttng_error_code *cmd_result) | |
811 | { | |
812 | struct cds_list_head trigger_list; | |
813 | struct channel_info *new_channel_info; | |
814 | struct channel_key *channel_key; | |
815 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; | |
816 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
817 | int trigger_count = 0; | |
818 | struct cds_lfht_iter iter; | |
819 | ||
820 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", | |
821 | channel_info->channel_name, channel_info->session_name, | |
822 | channel_info->key.key, channel_info->key.domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
823 | ||
824 | CDS_INIT_LIST_HEAD(&trigger_list); | |
825 | ||
826 | new_channel_info = channel_info_copy(channel_info); | |
827 | if (!new_channel_info) { | |
828 | goto error; | |
829 | } | |
830 | ||
831 | channel_key = &new_channel_info->key; | |
832 | ||
833 | /* Build a list of all triggers applying to the new channel. */ | |
834 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
835 | node) { | |
836 | struct lttng_trigger_list_element *new_element; | |
837 | ||
838 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, | |
839 | channel_info)) { | |
840 | continue; | |
841 | } | |
842 | ||
843 | new_element = zmalloc(sizeof(*new_element)); | |
844 | if (!new_element) { | |
845 | goto error; | |
846 | } | |
847 | CDS_INIT_LIST_HEAD(&new_element->node); | |
848 | new_element->trigger = trigger_ht_element->trigger; | |
849 | cds_list_add(&new_element->node, &trigger_list); | |
850 | trigger_count++; | |
851 | } | |
852 | ||
853 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", | |
854 | trigger_count); | |
855 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); | |
856 | if (!channel_trigger_list) { | |
857 | goto error; | |
858 | } | |
859 | channel_trigger_list->channel_key = *channel_key; | |
860 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); | |
861 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); | |
862 | cds_list_splice(&trigger_list, &channel_trigger_list->list); | |
863 | ||
864 | rcu_read_lock(); | |
865 | /* Add channel to the channel_ht which owns the channel_infos. */ | |
866 | cds_lfht_add(state->channels_ht, | |
867 | hash_channel_key(channel_key), | |
868 | &new_channel_info->channels_ht_node); | |
869 | /* | |
870 | * Add the list of triggers associated with this channel to the | |
871 | * channel_triggers_ht. | |
872 | */ | |
873 | cds_lfht_add(state->channel_triggers_ht, | |
874 | hash_channel_key(channel_key), | |
875 | &channel_trigger_list->channel_triggers_ht_node); | |
876 | rcu_read_unlock(); | |
877 | *cmd_result = LTTNG_OK; | |
878 | return 0; | |
879 | error: | |
880 | /* Empty trigger list */ | |
881 | channel_info_destroy(new_channel_info); | |
882 | return 1; | |
883 | } | |
884 | ||
885 | static | |
886 | int handle_notification_thread_command_remove_channel( | |
887 | struct notification_thread_state *state, | |
888 | uint64_t channel_key, enum lttng_domain_type domain, | |
889 | enum lttng_error_code *cmd_result) | |
890 | { | |
891 | struct cds_lfht_node *node; | |
892 | struct cds_lfht_iter iter; | |
893 | struct lttng_channel_trigger_list *trigger_list; | |
894 | struct lttng_trigger_list_element *trigger_list_element, *tmp; | |
895 | struct channel_key key = { .key = channel_key, .domain = domain }; | |
896 | struct channel_info *channel_info; | |
897 | ||
898 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", | |
899 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
900 | ||
901 | rcu_read_lock(); | |
902 | ||
903 | cds_lfht_lookup(state->channel_triggers_ht, | |
904 | hash_channel_key(&key), | |
905 | match_channel_trigger_list, | |
906 | &key, | |
907 | &iter); | |
908 | node = cds_lfht_iter_get_node(&iter); | |
909 | /* | |
910 | * There is a severe internal error if we are being asked to remove a | |
911 | * channel that doesn't exist. | |
912 | */ | |
913 | if (!node) { | |
914 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); | |
915 | goto end; | |
916 | } | |
917 | ||
918 | /* Free the list of triggers associated with this channel. */ | |
919 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
920 | channel_triggers_ht_node); | |
921 | cds_list_for_each_entry_safe(trigger_list_element, tmp, | |
922 | &trigger_list->list, node) { | |
923 | cds_list_del(&trigger_list_element->node); | |
924 | free(trigger_list_element); | |
925 | } | |
926 | cds_lfht_del(state->channel_triggers_ht, node); | |
927 | free(trigger_list); | |
928 | ||
929 | /* Free sampled channel state. */ | |
930 | cds_lfht_lookup(state->channel_state_ht, | |
931 | hash_channel_key(&key), | |
932 | match_channel_state_sample, | |
933 | &key, | |
934 | &iter); | |
935 | node = cds_lfht_iter_get_node(&iter); | |
936 | /* | |
937 | * This is expected to be NULL if the channel is destroyed before we | |
938 | * received a sample. | |
939 | */ | |
940 | if (node) { | |
941 | struct channel_state_sample *sample = caa_container_of(node, | |
942 | struct channel_state_sample, | |
943 | channel_state_ht_node); | |
944 | ||
945 | cds_lfht_del(state->channel_state_ht, node); | |
946 | free(sample); | |
947 | } | |
948 | ||
949 | /* Remove the channel from the channels_ht and free it. */ | |
950 | cds_lfht_lookup(state->channels_ht, | |
951 | hash_channel_key(&key), | |
952 | match_channel_info, | |
953 | &key, | |
954 | &iter); | |
955 | node = cds_lfht_iter_get_node(&iter); | |
956 | assert(node); | |
957 | channel_info = caa_container_of(node, struct channel_info, | |
958 | channels_ht_node); | |
959 | cds_lfht_del(state->channels_ht, node); | |
960 | channel_info_destroy(channel_info); | |
961 | end: | |
962 | rcu_read_unlock(); | |
963 | *cmd_result = LTTNG_OK; | |
964 | return 0; | |
965 | } | |
966 | ||
1da26331 JG |
967 | static |
968 | int condition_is_supported(struct lttng_condition *condition) | |
969 | { | |
970 | int ret; | |
971 | ||
972 | switch (lttng_condition_get_type(condition)) { | |
973 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
974 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
975 | { | |
976 | enum lttng_domain_type domain; | |
977 | ||
978 | ret = lttng_condition_buffer_usage_get_domain_type(condition, | |
979 | &domain); | |
980 | if (ret) { | |
981 | ret = -1; | |
982 | goto end; | |
983 | } | |
984 | ||
985 | if (domain != LTTNG_DOMAIN_KERNEL) { | |
986 | ret = 1; | |
987 | goto end; | |
988 | } | |
989 | ||
990 | /* | |
991 | * Older kernel tracers don't expose the API to monitor their | |
992 | * buffers. Therefore, we reject triggers that require that | |
993 | * mechanism to be available to be evaluated. | |
994 | */ | |
995 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( | |
996 | kernel_tracer_fd); | |
997 | break; | |
998 | } | |
999 | default: | |
1000 | ret = 1; | |
1001 | } | |
1002 | end: | |
1003 | return ret; | |
1004 | } | |
1005 | ||
ab0ee2ca JG |
1006 | /* |
1007 | * FIXME A client's credentials are not checked when registering a trigger, nor | |
1008 | * are they stored alongside with the trigger. | |
1009 | * | |
1da26331 | 1010 | * The effects of this are benign since: |
ab0ee2ca JG |
1011 | * - The client will succeed in registering the trigger, as it is valid, |
1012 | * - The trigger will, internally, be bound to the channel, | |
1013 | * - The notifications will not be sent since the client's credentials | |
1014 | * are checked against the channel at that moment. | |
1da26331 JG |
1015 | * |
1016 | * If this function returns a non-zero value, it means something is | |
50ca7858 | 1017 | * fundamentally broken and the whole subsystem/thread will be torn down. |
1da26331 JG |
1018 | * |
1019 | * If a non-fatal error occurs, just set the cmd_result to the appropriate | |
1020 | * error code. | |
ab0ee2ca JG |
1021 | */ |
1022 | static | |
1023 | int handle_notification_thread_command_register_trigger( | |
1024 | struct notification_thread_state *state, | |
1025 | struct lttng_trigger *trigger, | |
1026 | enum lttng_error_code *cmd_result) | |
1027 | { | |
1028 | int ret = 0; | |
1029 | struct lttng_condition *condition; | |
1030 | struct notification_client *client; | |
1031 | struct notification_client_list *client_list = NULL; | |
1032 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1033 | struct notification_client_list_element *client_list_element, *tmp; | |
1034 | struct cds_lfht_node *node; | |
1035 | struct cds_lfht_iter iter; | |
1036 | struct channel_info *channel; | |
1037 | bool free_trigger = true; | |
1038 | ||
1039 | rcu_read_lock(); | |
1040 | ||
1041 | condition = lttng_trigger_get_condition(trigger); | |
1da26331 JG |
1042 | assert(condition); |
1043 | ||
1044 | ret = condition_is_supported(condition); | |
1045 | if (ret < 0) { | |
1046 | goto error; | |
1047 | } else if (ret == 0) { | |
1048 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; | |
1049 | goto error; | |
1050 | } else { | |
1051 | /* Feature is supported, continue. */ | |
1052 | ret = 0; | |
1053 | } | |
1054 | ||
ab0ee2ca JG |
1055 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
1056 | if (!trigger_ht_element) { | |
1057 | ret = -1; | |
1058 | goto error; | |
1059 | } | |
1060 | ||
1061 | /* Add trigger to the trigger_ht. */ | |
1062 | cds_lfht_node_init(&trigger_ht_element->node); | |
1063 | trigger_ht_element->trigger = trigger; | |
1064 | ||
1065 | node = cds_lfht_add_unique(state->triggers_ht, | |
1066 | lttng_condition_hash(condition), | |
1067 | match_condition, | |
1068 | condition, | |
1069 | &trigger_ht_element->node); | |
1070 | if (node != &trigger_ht_element->node) { | |
1071 | /* Not a fatal error, simply report it to the client. */ | |
1072 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; | |
1073 | goto error_free_ht_element; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * Ownership of the trigger and of its wrapper was transfered to | |
1078 | * the triggers_ht. | |
1079 | */ | |
1080 | trigger_ht_element = NULL; | |
1081 | free_trigger = false; | |
1082 | ||
1083 | /* | |
1084 | * The rest only applies to triggers that have a "notify" action. | |
1085 | * It is not skipped as this is the only action type currently | |
1086 | * supported. | |
1087 | */ | |
1088 | client_list = zmalloc(sizeof(*client_list)); | |
1089 | if (!client_list) { | |
1090 | ret = -1; | |
1091 | goto error_free_ht_element; | |
1092 | } | |
1093 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); | |
1094 | CDS_INIT_LIST_HEAD(&client_list->list); | |
1095 | client_list->trigger = trigger; | |
1096 | ||
1097 | /* Build a list of clients to which this new trigger applies. */ | |
1098 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1099 | client_socket_ht_node) { | |
1100 | if (!trigger_applies_to_client(trigger, client)) { | |
1101 | continue; | |
1102 | } | |
1103 | ||
1104 | client_list_element = zmalloc(sizeof(*client_list_element)); | |
1105 | if (!client_list_element) { | |
1106 | ret = -1; | |
1107 | goto error_free_client_list; | |
1108 | } | |
1109 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
1110 | client_list_element->client = client; | |
1111 | cds_list_add(&client_list_element->node, &client_list->list); | |
1112 | } | |
1113 | ||
1114 | cds_lfht_add(state->notification_trigger_clients_ht, | |
1115 | lttng_condition_hash(condition), | |
1116 | &client_list->notification_trigger_ht_node); | |
ab0ee2ca JG |
1117 | |
1118 | /* | |
1119 | * Add the trigger to list of triggers bound to the channels currently | |
1120 | * known. | |
1121 | */ | |
1122 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, | |
1123 | channels_ht_node) { | |
1124 | struct lttng_trigger_list_element *trigger_list_element; | |
1125 | struct lttng_channel_trigger_list *trigger_list; | |
1126 | ||
1127 | if (!trigger_applies_to_channel(trigger, channel)) { | |
1128 | continue; | |
1129 | } | |
1130 | ||
1131 | cds_lfht_lookup(state->channel_triggers_ht, | |
1132 | hash_channel_key(&channel->key), | |
1133 | match_channel_trigger_list, | |
1134 | &channel->key, | |
1135 | &iter); | |
1136 | node = cds_lfht_iter_get_node(&iter); | |
1137 | assert(node); | |
ab0ee2ca JG |
1138 | trigger_list = caa_container_of(node, |
1139 | struct lttng_channel_trigger_list, | |
1140 | channel_triggers_ht_node); | |
1141 | ||
1142 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); | |
1143 | if (!trigger_list_element) { | |
1144 | ret = -1; | |
1145 | goto error_free_client_list; | |
1146 | } | |
1147 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); | |
1148 | trigger_list_element->trigger = trigger; | |
1149 | cds_list_add(&trigger_list_element->node, &trigger_list->list); | |
e4db5ace | 1150 | |
ab0ee2ca JG |
1151 | /* A trigger can only apply to one channel. */ |
1152 | break; | |
1153 | } | |
1154 | ||
2ae99f0b JG |
1155 | /* |
1156 | * Since there is nothing preventing clients from subscribing to a | |
1157 | * condition before the corresponding trigger is registered, we have | |
1158 | * to evaluate this new condition right away. | |
1159 | * | |
1160 | * At some point, we were waiting for the next "evaluation" (e.g. on | |
1161 | * reception of a channel sample) to evaluate this new condition, but | |
1162 | * that was broken. | |
1163 | * | |
1164 | * The reason it was broken is that waiting for the next sample | |
1165 | * does not allow us to properly handle transitions for edge-triggered | |
1166 | * conditions. | |
1167 | * | |
1168 | * Consider this example: when we handle a new channel sample, we | |
1169 | * evaluate each conditions twice: once with the previous state, and | |
1170 | * again with the newest state. We then use those two results to | |
1171 | * determine whether a state change happened: a condition was false and | |
1172 | * became true. If a state change happened, we have to notify clients. | |
1173 | * | |
1174 | * Now, if a client subscribes to a given notification and registers | |
1175 | * a trigger *after* that subscription, we have to make sure the | |
1176 | * condition is evaluated at this point while considering only the | |
1177 | * current state. Otherwise, the next evaluation cycle may only see | |
1178 | * that the evaluations remain the same (true for samples n-1 and n) and | |
1179 | * the client will never know that the condition has been met. | |
1180 | */ | |
1181 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1182 | &client_list->list, node) { | |
1183 | ret = evaluate_condition_for_client(trigger, condition, | |
1184 | client_list_element->client, state); | |
1185 | if (ret) { | |
1186 | goto error_free_client_list; | |
1187 | } | |
1188 | } | |
1189 | ||
1190 | /* | |
1191 | * Client list ownership transferred to the | |
1192 | * notification_trigger_clients_ht. | |
1193 | */ | |
1194 | client_list = NULL; | |
1195 | ||
ab0ee2ca JG |
1196 | *cmd_result = LTTNG_OK; |
1197 | error_free_client_list: | |
1198 | if (client_list) { | |
1199 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1200 | &client_list->list, node) { | |
1201 | free(client_list_element); | |
1202 | } | |
1203 | free(client_list); | |
1204 | } | |
1205 | error_free_ht_element: | |
1206 | free(trigger_ht_element); | |
1207 | error: | |
1208 | if (free_trigger) { | |
1209 | struct lttng_action *action = lttng_trigger_get_action(trigger); | |
1210 | ||
1211 | lttng_condition_destroy(condition); | |
1212 | lttng_action_destroy(action); | |
1213 | lttng_trigger_destroy(trigger); | |
1214 | } | |
1215 | rcu_read_unlock(); | |
1216 | return ret; | |
1217 | } | |
1218 | ||
cc2295b5 | 1219 | static |
ab0ee2ca JG |
1220 | int handle_notification_thread_command_unregister_trigger( |
1221 | struct notification_thread_state *state, | |
1222 | struct lttng_trigger *trigger, | |
1223 | enum lttng_error_code *_cmd_reply) | |
1224 | { | |
1225 | struct cds_lfht_iter iter; | |
1226 | struct cds_lfht_node *node, *triggers_ht_node; | |
1227 | struct lttng_channel_trigger_list *trigger_list; | |
1228 | struct notification_client_list *client_list; | |
1229 | struct notification_client_list_element *client_list_element, *tmp; | |
1230 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1231 | struct lttng_condition *condition = lttng_trigger_get_condition( | |
1232 | trigger); | |
1233 | struct lttng_action *action; | |
1234 | enum lttng_error_code cmd_reply; | |
1235 | ||
1236 | rcu_read_lock(); | |
1237 | ||
1238 | cds_lfht_lookup(state->triggers_ht, | |
1239 | lttng_condition_hash(condition), | |
1240 | match_condition, | |
1241 | condition, | |
1242 | &iter); | |
1243 | triggers_ht_node = cds_lfht_iter_get_node(&iter); | |
1244 | if (!triggers_ht_node) { | |
1245 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; | |
1246 | goto end; | |
1247 | } else { | |
1248 | cmd_reply = LTTNG_OK; | |
1249 | } | |
1250 | ||
1251 | /* Remove trigger from channel_triggers_ht. */ | |
1252 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, | |
1253 | channel_triggers_ht_node) { | |
1254 | struct lttng_trigger_list_element *trigger_element, *tmp; | |
1255 | ||
1256 | cds_list_for_each_entry_safe(trigger_element, tmp, | |
1257 | &trigger_list->list, node) { | |
1258 | struct lttng_condition *current_condition = | |
1259 | lttng_trigger_get_condition( | |
1260 | trigger_element->trigger); | |
1261 | ||
1262 | assert(current_condition); | |
1263 | if (!lttng_condition_is_equal(condition, | |
1264 | current_condition)) { | |
1265 | continue; | |
1266 | } | |
1267 | ||
1268 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); | |
1269 | cds_list_del(&trigger_element->node); | |
e4db5ace JR |
1270 | /* A trigger can only appear once per channel */ |
1271 | break; | |
ab0ee2ca JG |
1272 | } |
1273 | } | |
1274 | ||
1275 | /* | |
1276 | * Remove and release the client list from | |
1277 | * notification_trigger_clients_ht. | |
1278 | */ | |
1279 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
1280 | lttng_condition_hash(condition), | |
1281 | match_client_list, | |
1282 | trigger, | |
1283 | &iter); | |
1284 | node = cds_lfht_iter_get_node(&iter); | |
1285 | assert(node); | |
1286 | client_list = caa_container_of(node, struct notification_client_list, | |
1287 | notification_trigger_ht_node); | |
1288 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1289 | &client_list->list, node) { | |
1290 | free(client_list_element); | |
1291 | } | |
1292 | cds_lfht_del(state->notification_trigger_clients_ht, node); | |
1293 | free(client_list); | |
1294 | ||
1295 | /* Remove trigger from triggers_ht. */ | |
1296 | trigger_ht_element = caa_container_of(triggers_ht_node, | |
1297 | struct lttng_trigger_ht_element, node); | |
1298 | cds_lfht_del(state->triggers_ht, triggers_ht_node); | |
1299 | ||
1300 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); | |
1301 | lttng_condition_destroy(condition); | |
1302 | action = lttng_trigger_get_action(trigger_ht_element->trigger); | |
1303 | lttng_action_destroy(action); | |
1304 | lttng_trigger_destroy(trigger_ht_element->trigger); | |
1305 | free(trigger_ht_element); | |
1306 | end: | |
1307 | rcu_read_unlock(); | |
1308 | if (_cmd_reply) { | |
1309 | *_cmd_reply = cmd_reply; | |
1310 | } | |
1311 | return 0; | |
1312 | } | |
1313 | ||
1314 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ | |
1315 | int handle_notification_thread_command( | |
1316 | struct notification_thread_handle *handle, | |
1317 | struct notification_thread_state *state) | |
1318 | { | |
1319 | int ret; | |
1320 | uint64_t counter; | |
1321 | struct notification_thread_command *cmd; | |
1322 | ||
1323 | /* Read event_fd to put it back into a quiescent state. */ | |
814b4934 | 1324 | ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, sizeof(counter)); |
ab0ee2ca JG |
1325 | if (ret == -1) { |
1326 | goto error; | |
1327 | } | |
1328 | ||
1329 | pthread_mutex_lock(&handle->cmd_queue.lock); | |
1330 | cmd = cds_list_first_entry(&handle->cmd_queue.list, | |
1331 | struct notification_thread_command, cmd_list_node); | |
1332 | switch (cmd->type) { | |
1333 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: | |
1334 | DBG("[notification-thread] Received register trigger command"); | |
1335 | ret = handle_notification_thread_command_register_trigger( | |
1336 | state, cmd->parameters.trigger, | |
1337 | &cmd->reply_code); | |
1338 | break; | |
1339 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: | |
1340 | DBG("[notification-thread] Received unregister trigger command"); | |
1341 | ret = handle_notification_thread_command_unregister_trigger( | |
1342 | state, cmd->parameters.trigger, | |
1343 | &cmd->reply_code); | |
1344 | break; | |
1345 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: | |
1346 | DBG("[notification-thread] Received add channel command"); | |
1347 | ret = handle_notification_thread_command_add_channel( | |
1348 | state, &cmd->parameters.add_channel, | |
1349 | &cmd->reply_code); | |
1350 | break; | |
1351 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: | |
1352 | DBG("[notification-thread] Received remove channel command"); | |
1353 | ret = handle_notification_thread_command_remove_channel( | |
1354 | state, cmd->parameters.remove_channel.key, | |
1355 | cmd->parameters.remove_channel.domain, | |
1356 | &cmd->reply_code); | |
1357 | break; | |
1358 | case NOTIFICATION_COMMAND_TYPE_QUIT: | |
1359 | DBG("[notification-thread] Received quit command"); | |
1360 | cmd->reply_code = LTTNG_OK; | |
1361 | ret = 1; | |
1362 | goto end; | |
1363 | default: | |
1364 | ERR("[notification-thread] Unknown internal command received"); | |
1365 | goto error_unlock; | |
1366 | } | |
1367 | ||
1368 | if (ret) { | |
1369 | goto error_unlock; | |
1370 | } | |
1371 | end: | |
1372 | cds_list_del(&cmd->cmd_list_node); | |
8ada111f | 1373 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1374 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1375 | return ret; | |
1376 | error_unlock: | |
1377 | /* Wake-up and return a fatal error to the calling thread. */ | |
8ada111f | 1378 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1379 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1380 | cmd->reply_code = LTTNG_ERR_FATAL; | |
1381 | error: | |
1382 | /* Indicate a fatal error to the caller. */ | |
1383 | return -1; | |
1384 | } | |
1385 | ||
1386 | static | |
1387 | unsigned long hash_client_socket(int socket) | |
1388 | { | |
1389 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); | |
1390 | } | |
1391 | ||
1392 | static | |
1393 | int socket_set_non_blocking(int socket) | |
1394 | { | |
1395 | int ret, flags; | |
1396 | ||
1397 | /* Set the pipe as non-blocking. */ | |
1398 | ret = fcntl(socket, F_GETFL, 0); | |
1399 | if (ret == -1) { | |
1400 | PERROR("fcntl get socket flags"); | |
1401 | goto end; | |
1402 | } | |
1403 | flags = ret; | |
1404 | ||
1405 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); | |
1406 | if (ret == -1) { | |
1407 | PERROR("fcntl set O_NONBLOCK socket flag"); | |
1408 | goto end; | |
1409 | } | |
1410 | DBG("Client socket (fd = %i) set as non-blocking", socket); | |
1411 | end: | |
1412 | return ret; | |
1413 | } | |
1414 | ||
1415 | static | |
14fa22f8 | 1416 | int client_reset_inbound_state(struct notification_client *client) |
ab0ee2ca JG |
1417 | { |
1418 | int ret; | |
1419 | ||
1420 | ret = lttng_dynamic_buffer_set_size( | |
1421 | &client->communication.inbound.buffer, 0); | |
1422 | assert(!ret); | |
1423 | ||
1424 | client->communication.inbound.bytes_to_receive = | |
1425 | sizeof(struct lttng_notification_channel_message); | |
1426 | client->communication.inbound.msg_type = | |
1427 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; | |
ab0ee2ca JG |
1428 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
1429 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); | |
14fa22f8 JG |
1430 | ret = lttng_dynamic_buffer_set_size( |
1431 | &client->communication.inbound.buffer, | |
1432 | client->communication.inbound.bytes_to_receive); | |
1433 | return ret; | |
ab0ee2ca JG |
1434 | } |
1435 | ||
1436 | int handle_notification_thread_client_connect( | |
1437 | struct notification_thread_state *state) | |
1438 | { | |
1439 | int ret; | |
1440 | struct notification_client *client; | |
1441 | ||
1442 | DBG("[notification-thread] Handling new notification channel client connection"); | |
1443 | ||
1444 | client = zmalloc(sizeof(*client)); | |
1445 | if (!client) { | |
1446 | /* Fatal error. */ | |
1447 | ret = -1; | |
1448 | goto error; | |
1449 | } | |
1450 | CDS_INIT_LIST_HEAD(&client->condition_list); | |
1451 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); | |
1452 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); | |
01ea340e | 1453 | client->communication.inbound.expect_creds = true; |
14fa22f8 JG |
1454 | ret = client_reset_inbound_state(client); |
1455 | if (ret) { | |
1456 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1457 | ret = 0; | |
1458 | goto error; | |
1459 | } | |
ab0ee2ca JG |
1460 | |
1461 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); | |
1462 | if (ret < 0) { | |
1463 | ERR("[notification-thread] Failed to accept new notification channel client connection"); | |
1464 | ret = 0; | |
1465 | goto error; | |
1466 | } | |
1467 | ||
1468 | client->socket = ret; | |
1469 | ||
1470 | ret = socket_set_non_blocking(client->socket); | |
1471 | if (ret) { | |
1472 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); | |
1473 | goto error; | |
1474 | } | |
1475 | ||
1476 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); | |
1477 | if (ret < 0) { | |
1478 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); | |
1479 | ret = 0; | |
1480 | goto error; | |
1481 | } | |
1482 | ||
1483 | ret = lttng_poll_add(&state->events, client->socket, | |
1484 | LPOLLIN | LPOLLERR | | |
1485 | LPOLLHUP | LPOLLRDHUP); | |
1486 | if (ret < 0) { | |
1487 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); | |
1488 | ret = 0; | |
1489 | goto error; | |
1490 | } | |
1491 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", | |
1492 | client->socket); | |
1493 | ||
ab0ee2ca JG |
1494 | rcu_read_lock(); |
1495 | cds_lfht_add(state->client_socket_ht, | |
1496 | hash_client_socket(client->socket), | |
1497 | &client->client_socket_ht_node); | |
1498 | rcu_read_unlock(); | |
1499 | ||
1500 | return ret; | |
1501 | error: | |
1502 | notification_client_destroy(client, state); | |
1503 | return ret; | |
1504 | } | |
1505 | ||
1506 | int handle_notification_thread_client_disconnect( | |
1507 | int client_socket, | |
1508 | struct notification_thread_state *state) | |
1509 | { | |
1510 | int ret = 0; | |
1511 | struct notification_client *client; | |
1512 | ||
1513 | rcu_read_lock(); | |
1514 | DBG("[notification-thread] Closing client connection (socket fd = %i)", | |
1515 | client_socket); | |
1516 | client = get_client_from_socket(client_socket, state); | |
1517 | if (!client) { | |
1518 | /* Internal state corruption, fatal error. */ | |
1519 | ERR("[notification-thread] Unable to find client (socket fd = %i)", | |
1520 | client_socket); | |
1521 | ret = -1; | |
1522 | goto end; | |
1523 | } | |
1524 | ||
1525 | ret = lttng_poll_del(&state->events, client_socket); | |
1526 | if (ret) { | |
1527 | ERR("[notification-thread] Failed to remove client socket from poll set"); | |
1528 | } | |
1529 | cds_lfht_del(state->client_socket_ht, | |
1530 | &client->client_socket_ht_node); | |
1531 | notification_client_destroy(client, state); | |
1532 | end: | |
1533 | rcu_read_unlock(); | |
1534 | return ret; | |
1535 | } | |
1536 | ||
1537 | int handle_notification_thread_client_disconnect_all( | |
1538 | struct notification_thread_state *state) | |
1539 | { | |
1540 | struct cds_lfht_iter iter; | |
1541 | struct notification_client *client; | |
1542 | bool error_encoutered = false; | |
1543 | ||
1544 | rcu_read_lock(); | |
1545 | DBG("[notification-thread] Closing all client connections"); | |
1546 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1547 | client_socket_ht_node) { | |
1548 | int ret; | |
1549 | ||
1550 | ret = handle_notification_thread_client_disconnect( | |
1551 | client->socket, state); | |
1552 | if (ret) { | |
1553 | error_encoutered = true; | |
1554 | } | |
1555 | } | |
1556 | rcu_read_unlock(); | |
1557 | return error_encoutered ? 1 : 0; | |
1558 | } | |
1559 | ||
1560 | int handle_notification_thread_trigger_unregister_all( | |
1561 | struct notification_thread_state *state) | |
1562 | { | |
4149ace8 | 1563 | bool error_occurred = false; |
ab0ee2ca JG |
1564 | struct cds_lfht_iter iter; |
1565 | struct lttng_trigger_ht_element *trigger_ht_element; | |
1566 | ||
1567 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
1568 | node) { | |
1569 | int ret = handle_notification_thread_command_unregister_trigger( | |
1570 | state, trigger_ht_element->trigger, NULL); | |
1571 | if (ret) { | |
4149ace8 | 1572 | error_occurred = true; |
ab0ee2ca JG |
1573 | } |
1574 | } | |
4149ace8 | 1575 | return error_occurred ? -1 : 0; |
ab0ee2ca JG |
1576 | } |
1577 | ||
1578 | static | |
1579 | int client_flush_outgoing_queue(struct notification_client *client, | |
1580 | struct notification_thread_state *state) | |
1581 | { | |
1582 | ssize_t ret; | |
1583 | size_t to_send_count; | |
1584 | ||
1585 | assert(client->communication.outbound.buffer.size != 0); | |
1586 | to_send_count = client->communication.outbound.buffer.size; | |
1587 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", | |
1588 | client->socket); | |
1589 | ||
1590 | ret = lttcomm_send_unix_sock_non_block(client->socket, | |
1591 | client->communication.outbound.buffer.data, | |
1592 | to_send_count); | |
1593 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || | |
1594 | (ret > 0 && ret < to_send_count)) { | |
1595 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", | |
1596 | client->socket); | |
1597 | to_send_count -= max(ret, 0); | |
1598 | ||
1599 | memcpy(client->communication.outbound.buffer.data, | |
1600 | client->communication.outbound.buffer.data + | |
1601 | client->communication.outbound.buffer.size - to_send_count, | |
1602 | to_send_count); | |
1603 | ret = lttng_dynamic_buffer_set_size( | |
1604 | &client->communication.outbound.buffer, | |
1605 | to_send_count); | |
1606 | if (ret) { | |
1607 | goto error; | |
1608 | } | |
1609 | ||
1610 | /* | |
1611 | * We want to be notified whenever there is buffer space | |
1612 | * available to send the rest of the payload. | |
1613 | */ | |
1614 | ret = lttng_poll_mod(&state->events, client->socket, | |
1615 | CLIENT_POLL_MASK_IN_OUT); | |
1616 | if (ret) { | |
1617 | goto error; | |
1618 | } | |
1619 | } else if (ret < 0) { | |
1620 | /* Generic error, disconnect the client. */ | |
1621 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", | |
1622 | client->socket); | |
1623 | ret = handle_notification_thread_client_disconnect( | |
1624 | client->socket, state); | |
1625 | if (ret) { | |
1626 | goto error; | |
1627 | } | |
1628 | } else { | |
1629 | /* No error and flushed the queue completely. */ | |
1630 | ret = lttng_dynamic_buffer_set_size( | |
1631 | &client->communication.outbound.buffer, 0); | |
1632 | if (ret) { | |
1633 | goto error; | |
1634 | } | |
1635 | ret = lttng_poll_mod(&state->events, client->socket, | |
1636 | CLIENT_POLL_MASK_IN); | |
1637 | if (ret) { | |
1638 | goto error; | |
1639 | } | |
1640 | ||
1641 | client->communication.outbound.queued_command_reply = false; | |
1642 | client->communication.outbound.dropped_notification = false; | |
1643 | } | |
1644 | ||
1645 | return 0; | |
1646 | error: | |
1647 | return -1; | |
1648 | } | |
1649 | ||
1650 | static | |
1651 | int client_send_command_reply(struct notification_client *client, | |
1652 | struct notification_thread_state *state, | |
1653 | enum lttng_notification_channel_status status) | |
1654 | { | |
1655 | int ret; | |
1656 | struct lttng_notification_channel_command_reply reply = { | |
1657 | .status = (int8_t) status, | |
1658 | }; | |
1659 | struct lttng_notification_channel_message msg = { | |
1660 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, | |
1661 | .size = sizeof(reply), | |
1662 | }; | |
1663 | char buffer[sizeof(msg) + sizeof(reply)]; | |
1664 | ||
1665 | if (client->communication.outbound.queued_command_reply) { | |
1666 | /* Protocol error. */ | |
1667 | goto error; | |
1668 | } | |
1669 | ||
1670 | memcpy(buffer, &msg, sizeof(msg)); | |
1671 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); | |
1672 | DBG("[notification-thread] Send command reply (%i)", (int) status); | |
1673 | ||
1674 | /* Enqueue buffer to outgoing queue and flush it. */ | |
1675 | ret = lttng_dynamic_buffer_append( | |
1676 | &client->communication.outbound.buffer, | |
1677 | buffer, sizeof(buffer)); | |
1678 | if (ret) { | |
1679 | goto error; | |
1680 | } | |
1681 | ||
1682 | ret = client_flush_outgoing_queue(client, state); | |
1683 | if (ret) { | |
1684 | goto error; | |
1685 | } | |
1686 | ||
1687 | if (client->communication.outbound.buffer.size != 0) { | |
1688 | /* Queue could not be emptied. */ | |
1689 | client->communication.outbound.queued_command_reply = true; | |
1690 | } | |
1691 | ||
1692 | return 0; | |
1693 | error: | |
1694 | return -1; | |
1695 | } | |
1696 | ||
1697 | static | |
1698 | int client_dispatch_message(struct notification_client *client, | |
1699 | struct notification_thread_state *state) | |
1700 | { | |
1701 | int ret = 0; | |
1702 | ||
1703 | if (client->communication.inbound.msg_type != | |
1704 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && | |
1705 | client->communication.inbound.msg_type != | |
1706 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && | |
1707 | !client->validated) { | |
1708 | WARN("[notification-thread] client attempted a command before handshake"); | |
1709 | ret = -1; | |
1710 | goto end; | |
1711 | } | |
1712 | ||
1713 | switch (client->communication.inbound.msg_type) { | |
1714 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: | |
1715 | { | |
1716 | /* | |
1717 | * Receiving message header. The function will be called again | |
1718 | * once the rest of the message as been received and can be | |
1719 | * interpreted. | |
1720 | */ | |
1721 | const struct lttng_notification_channel_message *msg; | |
1722 | ||
1723 | assert(sizeof(*msg) == | |
1724 | client->communication.inbound.buffer.size); | |
1725 | msg = (const struct lttng_notification_channel_message *) | |
1726 | client->communication.inbound.buffer.data; | |
1727 | ||
1728 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
1729 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); | |
1730 | ret = -1; | |
1731 | goto end; | |
1732 | } | |
1733 | ||
1734 | switch (msg->type) { | |
1735 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
1736 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
1737 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1738 | break; | |
1739 | default: | |
1740 | ret = -1; | |
1741 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); | |
1742 | goto end; | |
1743 | } | |
1744 | ||
1745 | client->communication.inbound.bytes_to_receive = msg->size; | |
1746 | client->communication.inbound.msg_type = | |
1747 | (enum lttng_notification_channel_message_type) msg->type; | |
ab0ee2ca | 1748 | ret = lttng_dynamic_buffer_set_size( |
14fa22f8 | 1749 | &client->communication.inbound.buffer, msg->size); |
ab0ee2ca JG |
1750 | if (ret) { |
1751 | goto end; | |
1752 | } | |
1753 | break; | |
1754 | } | |
1755 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1756 | { | |
1757 | struct lttng_notification_channel_command_handshake *handshake_client; | |
1758 | struct lttng_notification_channel_command_handshake handshake_reply = { | |
1759 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
1760 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
1761 | }; | |
1762 | struct lttng_notification_channel_message msg_header = { | |
1763 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
1764 | .size = sizeof(handshake_reply), | |
1765 | }; | |
1766 | enum lttng_notification_channel_status status = | |
1767 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
1768 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; | |
1769 | ||
1770 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
1771 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, | |
1772 | sizeof(handshake_reply)); | |
1773 | ||
1774 | handshake_client = | |
1775 | (struct lttng_notification_channel_command_handshake *) | |
1776 | client->communication.inbound.buffer.data; | |
47a32869 | 1777 | client->major = handshake_client->major; |
ab0ee2ca JG |
1778 | client->minor = handshake_client->minor; |
1779 | if (!client->communication.inbound.creds_received) { | |
1780 | ERR("[notification-thread] No credentials received from client"); | |
1781 | ret = -1; | |
1782 | goto end; | |
1783 | } | |
1784 | ||
1785 | client->uid = LTTNG_SOCK_GET_UID_CRED( | |
1786 | &client->communication.inbound.creds); | |
1787 | client->gid = LTTNG_SOCK_GET_GID_CRED( | |
1788 | &client->communication.inbound.creds); | |
1789 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", | |
1790 | client->uid, client->gid, (int) client->major, | |
1791 | (int) client->minor); | |
1792 | ||
1793 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
1794 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; | |
1795 | } | |
1796 | ||
1797 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, | |
1798 | send_buffer, sizeof(send_buffer)); | |
1799 | if (ret) { | |
1800 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); | |
1801 | goto end; | |
1802 | } | |
1803 | ||
1804 | ret = client_flush_outgoing_queue(client, state); | |
1805 | if (ret) { | |
1806 | goto end; | |
1807 | } | |
1808 | ||
1809 | ret = client_send_command_reply(client, state, status); | |
1810 | if (ret) { | |
1811 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
1812 | goto end; | |
1813 | } | |
1814 | ||
1815 | /* Set reception state to receive the next message header. */ | |
14fa22f8 JG |
1816 | ret = client_reset_inbound_state(client); |
1817 | if (ret) { | |
1818 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1819 | goto end; | |
1820 | } | |
ab0ee2ca JG |
1821 | client->validated = true; |
1822 | break; | |
1823 | } | |
1824 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
1825 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
1826 | { | |
1827 | struct lttng_condition *condition; | |
1828 | enum lttng_notification_channel_status status = | |
1829 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
1830 | const struct lttng_buffer_view condition_view = | |
1831 | lttng_buffer_view_from_dynamic_buffer( | |
1832 | &client->communication.inbound.buffer, | |
1833 | 0, -1); | |
1834 | size_t expected_condition_size = | |
1835 | client->communication.inbound.buffer.size; | |
1836 | ||
1837 | ret = lttng_condition_create_from_buffer(&condition_view, | |
1838 | &condition); | |
1839 | if (ret != expected_condition_size) { | |
1840 | ERR("[notification-thread] Malformed condition received from client"); | |
1841 | goto end; | |
1842 | } | |
1843 | ||
1844 | if (client->communication.inbound.msg_type == | |
1845 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { | |
ab0ee2ca JG |
1846 | ret = notification_thread_client_subscribe(client, |
1847 | condition, state, &status); | |
1848 | } else { | |
1849 | ret = notification_thread_client_unsubscribe(client, | |
1850 | condition, state, &status); | |
1851 | } | |
1852 | if (ret) { | |
1853 | goto end; | |
1854 | } | |
1855 | ||
1856 | ret = client_send_command_reply(client, state, status); | |
1857 | if (ret) { | |
1858 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
1859 | goto end; | |
1860 | } | |
1861 | ||
1862 | /* Set reception state to receive the next message header. */ | |
14fa22f8 JG |
1863 | ret = client_reset_inbound_state(client); |
1864 | if (ret) { | |
1865 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1866 | goto end; | |
1867 | } | |
ab0ee2ca JG |
1868 | break; |
1869 | } | |
1870 | default: | |
1871 | abort(); | |
1872 | } | |
1873 | end: | |
1874 | return ret; | |
1875 | } | |
1876 | ||
1877 | /* Incoming data from client. */ | |
1878 | int handle_notification_thread_client_in( | |
1879 | struct notification_thread_state *state, int socket) | |
1880 | { | |
14fa22f8 | 1881 | int ret = 0; |
ab0ee2ca JG |
1882 | struct notification_client *client; |
1883 | ssize_t recv_ret; | |
1884 | size_t offset; | |
1885 | ||
1886 | client = get_client_from_socket(socket, state); | |
1887 | if (!client) { | |
1888 | /* Internal error, abort. */ | |
1889 | ret = -1; | |
1890 | goto end; | |
1891 | } | |
1892 | ||
14fa22f8 JG |
1893 | offset = client->communication.inbound.buffer.size - |
1894 | client->communication.inbound.bytes_to_receive; | |
01ea340e | 1895 | if (client->communication.inbound.expect_creds) { |
ab0ee2ca JG |
1896 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
1897 | client->communication.inbound.buffer.data + offset, | |
1898 | client->communication.inbound.bytes_to_receive, | |
1899 | &client->communication.inbound.creds); | |
1900 | if (recv_ret > 0) { | |
01ea340e | 1901 | client->communication.inbound.expect_creds = false; |
ab0ee2ca JG |
1902 | client->communication.inbound.creds_received = true; |
1903 | } | |
1904 | } else { | |
1905 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, | |
1906 | client->communication.inbound.buffer.data + offset, | |
1907 | client->communication.inbound.bytes_to_receive); | |
1908 | } | |
1909 | if (recv_ret < 0) { | |
1910 | goto error_disconnect_client; | |
1911 | } | |
1912 | ||
1913 | client->communication.inbound.bytes_to_receive -= recv_ret; | |
ab0ee2ca JG |
1914 | if (client->communication.inbound.bytes_to_receive == 0) { |
1915 | ret = client_dispatch_message(client, state); | |
1916 | if (ret) { | |
1917 | /* | |
1918 | * Only returns an error if this client must be | |
1919 | * disconnected. | |
1920 | */ | |
1921 | goto error_disconnect_client; | |
1922 | } | |
1923 | } else { | |
1924 | goto end; | |
1925 | } | |
1926 | end: | |
1927 | return ret; | |
1928 | error_disconnect_client: | |
1929 | ret = handle_notification_thread_client_disconnect(socket, state); | |
1930 | return ret; | |
1931 | } | |
1932 | ||
1933 | /* Client ready to receive outgoing data. */ | |
1934 | int handle_notification_thread_client_out( | |
1935 | struct notification_thread_state *state, int socket) | |
1936 | { | |
1937 | int ret; | |
1938 | struct notification_client *client; | |
1939 | ||
1940 | client = get_client_from_socket(socket, state); | |
1941 | if (!client) { | |
1942 | /* Internal error, abort. */ | |
1943 | ret = -1; | |
1944 | goto end; | |
1945 | } | |
1946 | ||
1947 | ret = client_flush_outgoing_queue(client, state); | |
1948 | if (ret) { | |
1949 | goto end; | |
1950 | } | |
1951 | end: | |
1952 | return ret; | |
1953 | } | |
1954 | ||
1955 | static | |
1956 | bool evaluate_buffer_usage_condition(struct lttng_condition *condition, | |
1957 | struct channel_state_sample *sample, uint64_t buffer_capacity) | |
1958 | { | |
1959 | bool result = false; | |
1960 | uint64_t threshold; | |
1961 | enum lttng_condition_type condition_type; | |
1962 | struct lttng_condition_buffer_usage *use_condition = container_of( | |
1963 | condition, struct lttng_condition_buffer_usage, | |
1964 | parent); | |
1965 | ||
1966 | if (!sample) { | |
1967 | goto end; | |
1968 | } | |
1969 | ||
1970 | if (use_condition->threshold_bytes.set) { | |
1971 | threshold = use_condition->threshold_bytes.value; | |
1972 | } else { | |
1973 | /* | |
1974 | * Threshold was expressed as a ratio. | |
1975 | * | |
1976 | * TODO the threshold (in bytes) of conditions expressed | |
1977 | * as a ratio of total buffer size could be cached to | |
1978 | * forego this double-multiplication or it could be performed | |
1979 | * as fixed-point math. | |
1980 | * | |
1981 | * Note that caching should accomodate the case where the | |
1982 | * condition applies to multiple channels (i.e. don't assume | |
1983 | * that all channels matching my_chann* have the same size...) | |
1984 | */ | |
1985 | threshold = (uint64_t) (use_condition->threshold_ratio.value * | |
1986 | (double) buffer_capacity); | |
1987 | } | |
1988 | ||
1989 | condition_type = lttng_condition_get_type(condition); | |
1990 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { | |
1991 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
1992 | threshold, sample->highest_usage); | |
1993 | ||
1994 | /* | |
1995 | * The low condition should only be triggered once _all_ of the | |
1996 | * streams in a channel have gone below the "low" threshold. | |
1997 | */ | |
1998 | if (sample->highest_usage <= threshold) { | |
1999 | result = true; | |
2000 | } | |
2001 | } else { | |
2002 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
2003 | threshold, sample->highest_usage); | |
2004 | ||
2005 | /* | |
2006 | * For high buffer usage scenarios, we want to trigger whenever | |
2007 | * _any_ of the streams has reached the "high" threshold. | |
2008 | */ | |
2009 | if (sample->highest_usage >= threshold) { | |
2010 | result = true; | |
2011 | } | |
2012 | } | |
2013 | end: | |
2014 | return result; | |
2015 | } | |
2016 | ||
2017 | static | |
2018 | int evaluate_condition(struct lttng_condition *condition, | |
2019 | struct lttng_evaluation **evaluation, | |
2020 | struct notification_thread_state *state, | |
2021 | struct channel_state_sample *previous_sample, | |
2022 | struct channel_state_sample *latest_sample, | |
2023 | uint64_t buffer_capacity) | |
2024 | { | |
2025 | int ret = 0; | |
2026 | enum lttng_condition_type condition_type; | |
2027 | bool previous_sample_result; | |
2028 | bool latest_sample_result; | |
2029 | ||
2030 | condition_type = lttng_condition_get_type(condition); | |
2031 | /* No other condition type supported for the moment. */ | |
2032 | assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || | |
2033 | condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); | |
2034 | ||
2035 | previous_sample_result = evaluate_buffer_usage_condition(condition, | |
2036 | previous_sample, buffer_capacity); | |
2037 | latest_sample_result = evaluate_buffer_usage_condition(condition, | |
2038 | latest_sample, buffer_capacity); | |
2039 | ||
2040 | if (!latest_sample_result || | |
2041 | (previous_sample_result == latest_sample_result)) { | |
2042 | /* | |
2043 | * Only trigger on a condition evaluation transition. | |
2044 | * | |
2045 | * NOTE: This edge-triggered logic may not be appropriate for | |
2046 | * future condition types. | |
2047 | */ | |
2048 | goto end; | |
2049 | } | |
2050 | ||
2051 | if (evaluation && latest_sample_result) { | |
2052 | *evaluation = lttng_evaluation_buffer_usage_create( | |
2053 | condition_type, | |
2054 | latest_sample->highest_usage, | |
2055 | buffer_capacity); | |
2056 | if (!*evaluation) { | |
2057 | ret = -1; | |
2058 | goto end; | |
2059 | } | |
2060 | } | |
2061 | end: | |
2062 | return ret; | |
2063 | } | |
2064 | ||
2065 | static | |
2066 | int client_enqueue_dropped_notification(struct notification_client *client, | |
2067 | struct notification_thread_state *state) | |
2068 | { | |
2069 | int ret; | |
2070 | struct lttng_notification_channel_message msg = { | |
2071 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, | |
2072 | .size = 0, | |
2073 | }; | |
2074 | ||
2075 | ret = lttng_dynamic_buffer_append( | |
2076 | &client->communication.outbound.buffer, &msg, | |
2077 | sizeof(msg)); | |
2078 | return ret; | |
2079 | } | |
2080 | ||
2081 | static | |
2082 | int send_evaluation_to_clients(struct lttng_trigger *trigger, | |
2083 | struct lttng_evaluation *evaluation, | |
2084 | struct notification_client_list* client_list, | |
2085 | struct notification_thread_state *state, | |
2086 | uid_t channel_uid, gid_t channel_gid) | |
2087 | { | |
2088 | int ret = 0; | |
2089 | struct lttng_dynamic_buffer msg_buffer; | |
2090 | struct notification_client_list_element *client_list_element, *tmp; | |
2091 | struct lttng_notification *notification; | |
2092 | struct lttng_condition *condition; | |
2093 | ssize_t expected_notification_size, notification_size; | |
2094 | struct lttng_notification_channel_message msg; | |
2095 | ||
2096 | lttng_dynamic_buffer_init(&msg_buffer); | |
2097 | ||
2098 | condition = lttng_trigger_get_condition(trigger); | |
2099 | assert(condition); | |
2100 | ||
2101 | notification = lttng_notification_create(condition, evaluation); | |
2102 | if (!notification) { | |
2103 | ret = -1; | |
2104 | goto end; | |
2105 | } | |
2106 | ||
2107 | expected_notification_size = lttng_notification_serialize(notification, | |
2108 | NULL); | |
2109 | if (expected_notification_size < 0) { | |
2110 | ERR("[notification-thread] Failed to get size of serialized notification"); | |
2111 | ret = -1; | |
2112 | goto end; | |
2113 | } | |
2114 | ||
2115 | msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; | |
2116 | msg.size = (uint32_t) expected_notification_size; | |
2117 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); | |
2118 | if (ret) { | |
2119 | goto end; | |
2120 | } | |
2121 | ||
2122 | ret = lttng_dynamic_buffer_set_size(&msg_buffer, | |
2123 | msg_buffer.size + expected_notification_size); | |
2124 | if (ret) { | |
2125 | goto end; | |
2126 | } | |
2127 | ||
2128 | notification_size = lttng_notification_serialize(notification, | |
2129 | msg_buffer.data + sizeof(msg)); | |
2130 | if (notification_size != expected_notification_size) { | |
2131 | ERR("[notification-thread] Failed to serialize notification"); | |
2132 | ret = -1; | |
2133 | goto end; | |
2134 | } | |
2135 | ||
2136 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
2137 | &client_list->list, node) { | |
2138 | struct notification_client *client = | |
2139 | client_list_element->client; | |
2140 | ||
2141 | if (client->uid != channel_uid && client->gid != channel_gid && | |
2142 | client->uid != 0) { | |
2143 | /* Client is not allowed to monitor this channel. */ | |
2144 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); | |
2145 | continue; | |
2146 | } | |
2147 | ||
2148 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", | |
2149 | client->socket, msg_buffer.size); | |
2150 | if (client->communication.outbound.buffer.size) { | |
2151 | /* | |
2152 | * Outgoing data is already buffered for this client; | |
2153 | * drop the notification and enqueue a "dropped | |
2154 | * notification" message if this is the first dropped | |
2155 | * notification since the socket spilled-over to the | |
2156 | * queue. | |
2157 | */ | |
2158 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", | |
2159 | client->socket); | |
2160 | if (!client->communication.outbound.dropped_notification) { | |
2161 | client->communication.outbound.dropped_notification = true; | |
2162 | ret = client_enqueue_dropped_notification( | |
2163 | client, state); | |
2164 | if (ret) { | |
2165 | goto end; | |
2166 | } | |
2167 | } | |
2168 | continue; | |
2169 | } | |
2170 | ||
2171 | ret = lttng_dynamic_buffer_append_buffer( | |
2172 | &client->communication.outbound.buffer, | |
2173 | &msg_buffer); | |
2174 | if (ret) { | |
2175 | goto end; | |
2176 | } | |
2177 | ||
2178 | ret = client_flush_outgoing_queue(client, state); | |
2179 | if (ret) { | |
2180 | goto end; | |
2181 | } | |
2182 | } | |
2183 | ret = 0; | |
2184 | end: | |
2185 | lttng_notification_destroy(notification); | |
2186 | lttng_dynamic_buffer_reset(&msg_buffer); | |
2187 | return ret; | |
2188 | } | |
2189 | ||
2190 | int handle_notification_thread_channel_sample( | |
2191 | struct notification_thread_state *state, int pipe, | |
2192 | enum lttng_domain_type domain) | |
2193 | { | |
2194 | int ret = 0; | |
2195 | struct lttcomm_consumer_channel_monitor_msg sample_msg; | |
2196 | struct channel_state_sample previous_sample, latest_sample; | |
2197 | struct channel_info *channel_info; | |
2198 | struct cds_lfht_node *node; | |
2199 | struct cds_lfht_iter iter; | |
2200 | struct lttng_channel_trigger_list *trigger_list; | |
2201 | struct lttng_trigger_list_element *trigger_list_element; | |
2202 | bool previous_sample_available = false; | |
2203 | ||
2204 | /* | |
2205 | * The monitoring pipe only holds messages smaller than PIPE_BUF, | |
2206 | * ensuring that read/write of sampling messages are atomic. | |
2207 | */ | |
7c2551ef | 2208 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
ab0ee2ca JG |
2209 | if (ret != sizeof(sample_msg)) { |
2210 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", | |
2211 | pipe); | |
2212 | ret = -1; | |
2213 | goto end; | |
2214 | } | |
2215 | ||
2216 | ret = 0; | |
2217 | latest_sample.key.key = sample_msg.key; | |
2218 | latest_sample.key.domain = domain; | |
2219 | latest_sample.highest_usage = sample_msg.highest; | |
2220 | latest_sample.lowest_usage = sample_msg.lowest; | |
2221 | ||
2222 | rcu_read_lock(); | |
2223 | ||
2224 | /* Retrieve the channel's informations */ | |
2225 | cds_lfht_lookup(state->channels_ht, | |
2226 | hash_channel_key(&latest_sample.key), | |
2227 | match_channel_info, | |
2228 | &latest_sample.key, | |
2229 | &iter); | |
2230 | node = cds_lfht_iter_get_node(&iter); | |
2231 | if (!node) { | |
2232 | /* | |
2233 | * Not an error since the consumer can push a sample to the pipe | |
2234 | * and the rest of the session daemon could notify us of the | |
2235 | * channel's destruction before we get a chance to process that | |
2236 | * sample. | |
2237 | */ | |
2238 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", | |
2239 | latest_sample.key.key, | |
2240 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : | |
2241 | "user space"); | |
2242 | goto end_unlock; | |
2243 | } | |
2244 | channel_info = caa_container_of(node, struct channel_info, | |
2245 | channels_ht_node); | |
2246 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64")", | |
2247 | channel_info->channel_name, | |
2248 | latest_sample.key.key, | |
2249 | channel_info->session_name, | |
2250 | latest_sample.highest_usage, | |
2251 | latest_sample.lowest_usage); | |
2252 | ||
2253 | /* Retrieve the channel's last sample, if it exists, and update it. */ | |
2254 | cds_lfht_lookup(state->channel_state_ht, | |
2255 | hash_channel_key(&latest_sample.key), | |
2256 | match_channel_state_sample, | |
2257 | &latest_sample.key, | |
2258 | &iter); | |
2259 | node = cds_lfht_iter_get_node(&iter); | |
2260 | if (node) { | |
2261 | struct channel_state_sample *stored_sample; | |
2262 | ||
2263 | /* Update the sample stored. */ | |
2264 | stored_sample = caa_container_of(node, | |
2265 | struct channel_state_sample, | |
2266 | channel_state_ht_node); | |
2267 | memcpy(&previous_sample, stored_sample, | |
2268 | sizeof(previous_sample)); | |
2269 | stored_sample->highest_usage = latest_sample.highest_usage; | |
2270 | stored_sample->lowest_usage = latest_sample.lowest_usage; | |
2271 | previous_sample_available = true; | |
2272 | } else { | |
2273 | /* | |
2274 | * This is the channel's first sample, allocate space for and | |
2275 | * store the new sample. | |
2276 | */ | |
2277 | struct channel_state_sample *stored_sample; | |
2278 | ||
2279 | stored_sample = zmalloc(sizeof(*stored_sample)); | |
2280 | if (!stored_sample) { | |
2281 | ret = -1; | |
2282 | goto end_unlock; | |
2283 | } | |
2284 | ||
2285 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); | |
2286 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); | |
2287 | cds_lfht_add(state->channel_state_ht, | |
2288 | hash_channel_key(&stored_sample->key), | |
2289 | &stored_sample->channel_state_ht_node); | |
2290 | } | |
2291 | ||
2292 | /* Find triggers associated with this channel. */ | |
2293 | cds_lfht_lookup(state->channel_triggers_ht, | |
2294 | hash_channel_key(&latest_sample.key), | |
2295 | match_channel_trigger_list, | |
2296 | &latest_sample.key, | |
2297 | &iter); | |
2298 | node = cds_lfht_iter_get_node(&iter); | |
2299 | if (!node) { | |
2300 | goto end_unlock; | |
2301 | } | |
2302 | ||
2303 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
2304 | channel_triggers_ht_node); | |
2305 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, | |
2306 | node) { | |
2307 | struct lttng_condition *condition; | |
2308 | struct lttng_action *action; | |
2309 | struct lttng_trigger *trigger; | |
2310 | struct notification_client_list *client_list; | |
2311 | struct lttng_evaluation *evaluation = NULL; | |
2312 | ||
2313 | trigger = trigger_list_element->trigger; | |
2314 | condition = lttng_trigger_get_condition(trigger); | |
2315 | assert(condition); | |
2316 | action = lttng_trigger_get_action(trigger); | |
2317 | ||
2318 | /* Notify actions are the only type currently supported. */ | |
2319 | assert(lttng_action_get_type(action) == | |
2320 | LTTNG_ACTION_TYPE_NOTIFY); | |
2321 | ||
2322 | /* | |
2323 | * Check if any client is subscribed to the result of this | |
2324 | * evaluation. | |
2325 | */ | |
2326 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
2327 | lttng_condition_hash(condition), | |
2328 | match_client_list, | |
2329 | trigger, | |
2330 | &iter); | |
2331 | node = cds_lfht_iter_get_node(&iter); | |
2332 | assert(node); | |
2333 | ||
2334 | client_list = caa_container_of(node, | |
2335 | struct notification_client_list, | |
2336 | notification_trigger_ht_node); | |
2337 | if (cds_list_empty(&client_list->list)) { | |
2338 | /* | |
2339 | * No clients interested in the evaluation's result, | |
2340 | * skip it. | |
2341 | */ | |
2342 | continue; | |
2343 | } | |
2344 | ||
2345 | ret = evaluate_condition(condition, &evaluation, state, | |
2346 | previous_sample_available ? &previous_sample : NULL, | |
2347 | &latest_sample, channel_info->capacity); | |
2348 | if (ret) { | |
2349 | goto end_unlock; | |
2350 | } | |
2351 | ||
2352 | if (!evaluation) { | |
2353 | continue; | |
2354 | } | |
2355 | ||
2356 | /* Dispatch evaluation result to all clients. */ | |
2357 | ret = send_evaluation_to_clients(trigger_list_element->trigger, | |
2358 | evaluation, client_list, state, | |
2359 | channel_info->uid, channel_info->gid); | |
2360 | if (ret) { | |
2361 | goto end_unlock; | |
2362 | } | |
2363 | } | |
2364 | end_unlock: | |
2365 | rcu_read_unlock(); | |
2366 | end: | |
2367 | return ret; | |
2368 | } |