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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 | ||
8abe313a JG |
171 | |
172 | static | |
173 | void session_info_destroy(void *_data); | |
174 | static | |
175 | void session_info_get(struct session_info *session_info); | |
176 | static | |
177 | void session_info_put(struct session_info *session_info); | |
178 | static | |
179 | struct session_info *session_info_create(const char *name, | |
180 | uid_t uid, gid_t gid); | |
181 | static | |
182 | void session_info_add_channel(struct session_info *session_info, | |
183 | struct channel_info *channel_info); | |
184 | static | |
185 | void session_info_remove_channel(struct session_info *session_info, | |
186 | struct channel_info *channel_info); | |
187 | ||
ab0ee2ca JG |
188 | static |
189 | int match_client(struct cds_lfht_node *node, const void *key) | |
190 | { | |
191 | /* This double-cast is intended to supress pointer-to-cast warning. */ | |
192 | int socket = (int) (intptr_t) key; | |
193 | struct notification_client *client; | |
194 | ||
195 | client = caa_container_of(node, struct notification_client, | |
196 | client_socket_ht_node); | |
197 | ||
198 | return !!(client->socket == socket); | |
199 | } | |
200 | ||
201 | static | |
202 | int match_channel_trigger_list(struct cds_lfht_node *node, const void *key) | |
203 | { | |
204 | struct channel_key *channel_key = (struct channel_key *) key; | |
205 | struct lttng_channel_trigger_list *trigger_list; | |
206 | ||
207 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
208 | channel_triggers_ht_node); | |
209 | ||
210 | return !!((channel_key->key == trigger_list->channel_key.key) && | |
211 | (channel_key->domain == trigger_list->channel_key.domain)); | |
212 | } | |
213 | ||
214 | static | |
215 | int match_channel_state_sample(struct cds_lfht_node *node, const void *key) | |
216 | { | |
217 | struct channel_key *channel_key = (struct channel_key *) key; | |
218 | struct channel_state_sample *sample; | |
219 | ||
220 | sample = caa_container_of(node, struct channel_state_sample, | |
221 | channel_state_ht_node); | |
222 | ||
223 | return !!((channel_key->key == sample->key.key) && | |
224 | (channel_key->domain == sample->key.domain)); | |
225 | } | |
226 | ||
227 | static | |
228 | int match_channel_info(struct cds_lfht_node *node, const void *key) | |
229 | { | |
230 | struct channel_key *channel_key = (struct channel_key *) key; | |
231 | struct channel_info *channel_info; | |
232 | ||
233 | channel_info = caa_container_of(node, struct channel_info, | |
234 | channels_ht_node); | |
235 | ||
236 | return !!((channel_key->key == channel_info->key.key) && | |
237 | (channel_key->domain == channel_info->key.domain)); | |
238 | } | |
239 | ||
240 | static | |
241 | int match_condition(struct cds_lfht_node *node, const void *key) | |
242 | { | |
243 | struct lttng_condition *condition_key = (struct lttng_condition *) key; | |
244 | struct lttng_trigger_ht_element *trigger; | |
245 | struct lttng_condition *condition; | |
246 | ||
247 | trigger = caa_container_of(node, struct lttng_trigger_ht_element, | |
248 | node); | |
249 | condition = lttng_trigger_get_condition(trigger->trigger); | |
250 | assert(condition); | |
251 | ||
252 | return !!lttng_condition_is_equal(condition_key, condition); | |
253 | } | |
254 | ||
255 | static | |
256 | int match_client_list(struct cds_lfht_node *node, const void *key) | |
257 | { | |
258 | struct lttng_trigger *trigger_key = (struct lttng_trigger *) key; | |
259 | struct notification_client_list *client_list; | |
260 | struct lttng_condition *condition; | |
261 | struct lttng_condition *condition_key = lttng_trigger_get_condition( | |
262 | trigger_key); | |
263 | ||
264 | assert(condition_key); | |
265 | ||
266 | client_list = caa_container_of(node, struct notification_client_list, | |
267 | notification_trigger_ht_node); | |
268 | condition = lttng_trigger_get_condition(client_list->trigger); | |
269 | ||
270 | return !!lttng_condition_is_equal(condition_key, condition); | |
271 | } | |
272 | ||
273 | static | |
274 | int match_client_list_condition(struct cds_lfht_node *node, const void *key) | |
275 | { | |
276 | struct lttng_condition *condition_key = (struct lttng_condition *) key; | |
277 | struct notification_client_list *client_list; | |
278 | struct lttng_condition *condition; | |
279 | ||
280 | assert(condition_key); | |
281 | ||
282 | client_list = caa_container_of(node, struct notification_client_list, | |
283 | notification_trigger_ht_node); | |
284 | condition = lttng_trigger_get_condition(client_list->trigger); | |
285 | ||
286 | return !!lttng_condition_is_equal(condition_key, condition); | |
287 | } | |
288 | ||
289 | static | |
290 | unsigned long lttng_condition_buffer_usage_hash( | |
291 | struct lttng_condition *_condition) | |
292 | { | |
293 | unsigned long hash = 0; | |
294 | struct lttng_condition_buffer_usage *condition; | |
295 | ||
296 | condition = container_of(_condition, | |
297 | struct lttng_condition_buffer_usage, parent); | |
298 | ||
299 | if (condition->session_name) { | |
300 | hash ^= hash_key_str(condition->session_name, lttng_ht_seed); | |
301 | } | |
302 | if (condition->channel_name) { | |
8f56701f | 303 | hash ^= hash_key_str(condition->channel_name, lttng_ht_seed); |
ab0ee2ca JG |
304 | } |
305 | if (condition->domain.set) { | |
306 | hash ^= hash_key_ulong( | |
307 | (void *) condition->domain.type, | |
308 | lttng_ht_seed); | |
309 | } | |
310 | if (condition->threshold_ratio.set) { | |
311 | uint64_t val; | |
312 | ||
313 | val = condition->threshold_ratio.value * (double) UINT32_MAX; | |
314 | hash ^= hash_key_u64(&val, lttng_ht_seed); | |
6633b0dd | 315 | } else if (condition->threshold_bytes.set) { |
ab0ee2ca JG |
316 | uint64_t val; |
317 | ||
318 | val = condition->threshold_bytes.value; | |
319 | hash ^= hash_key_u64(&val, lttng_ht_seed); | |
320 | } | |
321 | return hash; | |
322 | } | |
323 | ||
324 | /* | |
325 | * The lttng_condition hashing code is kept in this file (rather than | |
326 | * condition.c) since it makes use of GPLv2 code (hashtable utils), which we | |
327 | * don't want to link in liblttng-ctl. | |
328 | */ | |
329 | static | |
330 | unsigned long lttng_condition_hash(struct lttng_condition *condition) | |
331 | { | |
332 | switch (condition->type) { | |
333 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
334 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
335 | return lttng_condition_buffer_usage_hash(condition); | |
336 | default: | |
337 | ERR("[notification-thread] Unexpected condition type caught"); | |
338 | abort(); | |
339 | } | |
340 | } | |
341 | ||
e4db5ace JR |
342 | static |
343 | unsigned long hash_channel_key(struct channel_key *key) | |
344 | { | |
345 | unsigned long key_hash = hash_key_u64(&key->key, lttng_ht_seed); | |
346 | unsigned long domain_hash = hash_key_ulong( | |
347 | (void *) (unsigned long) key->domain, lttng_ht_seed); | |
348 | ||
349 | return key_hash ^ domain_hash; | |
350 | } | |
351 | ||
ab0ee2ca JG |
352 | static |
353 | void channel_info_destroy(struct channel_info *channel_info) | |
354 | { | |
355 | if (!channel_info) { | |
356 | return; | |
357 | } | |
358 | ||
8abe313a JG |
359 | if (channel_info->session_info) { |
360 | session_info_remove_channel(channel_info->session_info, | |
361 | channel_info); | |
362 | session_info_put(channel_info->session_info); | |
ab0ee2ca | 363 | } |
8abe313a JG |
364 | if (channel_info->name) { |
365 | free(channel_info->name); | |
ab0ee2ca JG |
366 | } |
367 | free(channel_info); | |
368 | } | |
369 | ||
8abe313a | 370 | /* Don't call directly, use the ref-counting mechanism. */ |
ab0ee2ca | 371 | static |
8abe313a | 372 | void session_info_destroy(void *_data) |
ab0ee2ca | 373 | { |
8abe313a | 374 | struct session_info *session_info = _data; |
ab0ee2ca | 375 | |
8abe313a JG |
376 | assert(session_info); |
377 | if (session_info->channel_infos_ht) { | |
378 | cds_lfht_destroy(session_info->channel_infos_ht, NULL); | |
379 | } | |
380 | free(session_info->name); | |
381 | free(session_info); | |
382 | } | |
ab0ee2ca | 383 | |
8abe313a JG |
384 | static |
385 | void session_info_get(struct session_info *session_info) | |
386 | { | |
387 | if (!session_info) { | |
388 | return; | |
389 | } | |
390 | lttng_ref_get(&session_info->ref); | |
391 | } | |
392 | ||
393 | static | |
394 | void session_info_put(struct session_info *session_info) | |
395 | { | |
396 | if (!session_info) { | |
397 | return; | |
ab0ee2ca | 398 | } |
8abe313a JG |
399 | lttng_ref_put(&session_info->ref); |
400 | } | |
401 | ||
402 | static | |
403 | struct session_info *session_info_create(const char *name, uid_t uid, gid_t gid) | |
404 | { | |
405 | struct session_info *session_info; | |
ab0ee2ca | 406 | |
8abe313a | 407 | assert(name); |
ab0ee2ca | 408 | |
8abe313a JG |
409 | session_info = zmalloc(sizeof(*session_info)); |
410 | if (!session_info) { | |
411 | goto end; | |
412 | } | |
413 | lttng_ref_init(&session_info->ref, session_info_destroy); | |
414 | ||
415 | session_info->channel_infos_ht = cds_lfht_new(DEFAULT_HT_SIZE, | |
416 | 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL); | |
417 | if (!session_info->channel_infos_ht) { | |
ab0ee2ca JG |
418 | goto error; |
419 | } | |
8abe313a JG |
420 | |
421 | cds_lfht_node_init(&session_info->sessions_ht_node); | |
422 | session_info->name = strdup(name); | |
423 | if (!session_info->name) { | |
ab0ee2ca JG |
424 | goto error; |
425 | } | |
8abe313a JG |
426 | session_info->uid = uid; |
427 | session_info->gid = gid; | |
428 | end: | |
429 | return session_info; | |
430 | error: | |
431 | session_info_put(session_info); | |
432 | return NULL; | |
433 | } | |
434 | ||
435 | static | |
436 | void session_info_add_channel(struct session_info *session_info, | |
437 | struct channel_info *channel_info) | |
438 | { | |
439 | rcu_read_lock(); | |
440 | cds_lfht_add(session_info->channel_infos_ht, | |
441 | hash_channel_key(&channel_info->key), | |
442 | &channel_info->session_info_channels_ht_node); | |
443 | rcu_read_unlock(); | |
444 | } | |
445 | ||
446 | static | |
447 | void session_info_remove_channel(struct session_info *session_info, | |
448 | struct channel_info *channel_info) | |
449 | { | |
450 | rcu_read_lock(); | |
451 | cds_lfht_del(session_info->channel_infos_ht, | |
452 | &channel_info->session_info_channels_ht_node); | |
453 | rcu_read_unlock(); | |
454 | } | |
455 | ||
456 | static | |
457 | struct channel_info *channel_info_create(const char *channel_name, | |
458 | struct channel_key *channel_key, uint64_t channel_capacity, | |
459 | struct session_info *session_info) | |
460 | { | |
461 | struct channel_info *channel_info = zmalloc(sizeof(*channel_info)); | |
462 | ||
463 | if (!channel_info) { | |
464 | goto end; | |
465 | } | |
466 | ||
ab0ee2ca | 467 | cds_lfht_node_init(&channel_info->channels_ht_node); |
8abe313a JG |
468 | cds_lfht_node_init(&channel_info->session_info_channels_ht_node); |
469 | memcpy(&channel_info->key, channel_key, sizeof(*channel_key)); | |
470 | channel_info->capacity = channel_capacity; | |
471 | ||
472 | channel_info->name = strdup(channel_name); | |
473 | if (!channel_info->name) { | |
474 | goto error; | |
475 | } | |
476 | ||
477 | /* | |
478 | * Set the references between session and channel infos: | |
479 | * - channel_info holds a strong reference to session_info | |
480 | * - session_info holds a weak reference to channel_info | |
481 | */ | |
482 | session_info_get(session_info); | |
483 | session_info_add_channel(session_info, channel_info); | |
484 | channel_info->session_info = session_info; | |
ab0ee2ca | 485 | end: |
8abe313a | 486 | return channel_info; |
ab0ee2ca | 487 | error: |
8abe313a | 488 | channel_info_destroy(channel_info); |
ab0ee2ca JG |
489 | return NULL; |
490 | } | |
491 | ||
e4db5ace JR |
492 | /* This function must be called with the RCU read lock held. */ |
493 | static | |
494 | int evaluate_condition_for_client(struct lttng_trigger *trigger, | |
495 | struct lttng_condition *condition, | |
496 | struct notification_client *client, | |
497 | struct notification_thread_state *state) | |
498 | { | |
499 | int ret; | |
500 | struct cds_lfht_iter iter; | |
501 | struct cds_lfht_node *node; | |
502 | struct channel_info *channel_info = NULL; | |
503 | struct channel_key *channel_key = NULL; | |
504 | struct channel_state_sample *last_sample = NULL; | |
505 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; | |
506 | struct lttng_evaluation *evaluation = NULL; | |
507 | struct notification_client_list client_list = { 0 }; | |
508 | struct notification_client_list_element client_list_element = { 0 }; | |
509 | ||
510 | assert(trigger); | |
511 | assert(condition); | |
512 | assert(client); | |
513 | assert(state); | |
514 | ||
515 | /* Find the channel associated with the trigger. */ | |
516 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, | |
517 | channel_trigger_list , channel_triggers_ht_node) { | |
518 | struct lttng_trigger_list_element *element; | |
519 | ||
520 | cds_list_for_each_entry(element, &channel_trigger_list->list, node) { | |
521 | struct lttng_condition *current_condition = | |
522 | lttng_trigger_get_condition( | |
523 | element->trigger); | |
524 | ||
525 | assert(current_condition); | |
526 | if (!lttng_condition_is_equal(condition, | |
2ae99f0b | 527 | current_condition)) { |
e4db5ace JR |
528 | continue; |
529 | } | |
530 | ||
531 | /* Found the trigger, save the channel key. */ | |
532 | channel_key = &channel_trigger_list->channel_key; | |
533 | break; | |
534 | } | |
535 | if (channel_key) { | |
536 | /* The channel key was found stop iteration. */ | |
537 | break; | |
538 | } | |
539 | } | |
540 | ||
541 | if (!channel_key){ | |
542 | /* No channel found; normal exit. */ | |
543 | DBG("[notification-thread] No channel associated with newly subscribed-to condition"); | |
544 | ret = 0; | |
545 | goto end; | |
546 | } | |
547 | ||
548 | /* Fetch channel info for the matching channel. */ | |
549 | cds_lfht_lookup(state->channels_ht, | |
550 | hash_channel_key(channel_key), | |
551 | match_channel_info, | |
552 | channel_key, | |
553 | &iter); | |
554 | node = cds_lfht_iter_get_node(&iter); | |
555 | assert(node); | |
556 | channel_info = caa_container_of(node, struct channel_info, | |
557 | channels_ht_node); | |
558 | ||
559 | /* Retrieve the channel's last sample, if it exists. */ | |
560 | cds_lfht_lookup(state->channel_state_ht, | |
561 | hash_channel_key(channel_key), | |
562 | match_channel_state_sample, | |
563 | channel_key, | |
564 | &iter); | |
565 | node = cds_lfht_iter_get_node(&iter); | |
566 | if (node) { | |
567 | last_sample = caa_container_of(node, | |
568 | struct channel_state_sample, | |
569 | channel_state_ht_node); | |
570 | } else { | |
571 | /* Nothing to evaluate, no sample was ever taken. Normal exit */ | |
572 | DBG("[notification-thread] No channel sample associated with newly subscribed-to condition"); | |
573 | ret = 0; | |
574 | goto end; | |
575 | } | |
576 | ||
577 | ret = evaluate_condition(condition, &evaluation, state, NULL, | |
578 | last_sample, channel_info->capacity); | |
579 | if (ret) { | |
066a3c82 | 580 | WARN("[notification-thread] Fatal error occurred while evaluating a newly subscribed-to condition"); |
e4db5ace JR |
581 | goto end; |
582 | } | |
583 | ||
584 | if (!evaluation) { | |
585 | /* Evaluation yielded nothing. Normal exit. */ | |
586 | DBG("[notification-thread] Newly subscribed-to condition evaluated to false, nothing to report to client"); | |
587 | ret = 0; | |
588 | goto end; | |
589 | } | |
590 | ||
591 | /* | |
592 | * Create a temporary client list with the client currently | |
593 | * subscribing. | |
594 | */ | |
595 | cds_lfht_node_init(&client_list.notification_trigger_ht_node); | |
596 | CDS_INIT_LIST_HEAD(&client_list.list); | |
597 | client_list.trigger = trigger; | |
598 | ||
599 | CDS_INIT_LIST_HEAD(&client_list_element.node); | |
600 | client_list_element.client = client; | |
601 | cds_list_add(&client_list_element.node, &client_list.list); | |
602 | ||
603 | /* Send evaluation result to the newly-subscribed client. */ | |
604 | DBG("[notification-thread] Newly subscribed-to condition evaluated to true, notifying client"); | |
605 | ret = send_evaluation_to_clients(trigger, evaluation, &client_list, | |
8abe313a JG |
606 | state, channel_info->session_info->uid, |
607 | channel_info->session_info->gid); | |
e4db5ace JR |
608 | |
609 | end: | |
610 | return ret; | |
611 | } | |
612 | ||
ab0ee2ca JG |
613 | static |
614 | int notification_thread_client_subscribe(struct notification_client *client, | |
615 | struct lttng_condition *condition, | |
616 | struct notification_thread_state *state, | |
617 | enum lttng_notification_channel_status *_status) | |
618 | { | |
619 | int ret = 0; | |
620 | struct cds_lfht_iter iter; | |
621 | struct cds_lfht_node *node; | |
622 | struct notification_client_list *client_list; | |
623 | struct lttng_condition_list_element *condition_list_element = NULL; | |
624 | struct notification_client_list_element *client_list_element = NULL; | |
625 | enum lttng_notification_channel_status status = | |
626 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
627 | ||
628 | /* | |
629 | * Ensure that the client has not already subscribed to this condition | |
630 | * before. | |
631 | */ | |
632 | cds_list_for_each_entry(condition_list_element, &client->condition_list, node) { | |
633 | if (lttng_condition_is_equal(condition_list_element->condition, | |
634 | condition)) { | |
635 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ALREADY_SUBSCRIBED; | |
636 | goto end; | |
637 | } | |
638 | } | |
639 | ||
640 | condition_list_element = zmalloc(sizeof(*condition_list_element)); | |
641 | if (!condition_list_element) { | |
642 | ret = -1; | |
643 | goto error; | |
644 | } | |
645 | client_list_element = zmalloc(sizeof(*client_list_element)); | |
646 | if (!client_list_element) { | |
647 | ret = -1; | |
648 | goto error; | |
649 | } | |
650 | ||
651 | rcu_read_lock(); | |
652 | ||
653 | /* | |
654 | * Add the newly-subscribed condition to the client's subscription list. | |
655 | */ | |
656 | CDS_INIT_LIST_HEAD(&condition_list_element->node); | |
657 | condition_list_element->condition = condition; | |
658 | cds_list_add(&condition_list_element->node, &client->condition_list); | |
659 | ||
ab0ee2ca JG |
660 | cds_lfht_lookup(state->notification_trigger_clients_ht, |
661 | lttng_condition_hash(condition), | |
662 | match_client_list_condition, | |
663 | condition, | |
664 | &iter); | |
665 | node = cds_lfht_iter_get_node(&iter); | |
666 | if (!node) { | |
2ae99f0b JG |
667 | /* |
668 | * No notification-emiting trigger registered with this | |
669 | * condition. We don't evaluate the condition right away | |
670 | * since this trigger is not registered yet. | |
671 | */ | |
4fb43b68 | 672 | free(client_list_element); |
ab0ee2ca JG |
673 | goto end_unlock; |
674 | } | |
675 | ||
676 | client_list = caa_container_of(node, struct notification_client_list, | |
677 | notification_trigger_ht_node); | |
2ae99f0b JG |
678 | /* |
679 | * The condition to which the client just subscribed is evaluated | |
680 | * at this point so that conditions that are already TRUE result | |
681 | * in a notification being sent out. | |
682 | */ | |
e4db5ace JR |
683 | if (evaluate_condition_for_client(client_list->trigger, condition, |
684 | client, state)) { | |
685 | WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting."); | |
686 | ret = -1; | |
687 | goto end_unlock; | |
688 | } | |
689 | ||
690 | /* | |
691 | * Add the client to the list of clients interested in a given trigger | |
692 | * if a "notification" trigger with a corresponding condition was | |
693 | * added prior. | |
694 | */ | |
ab0ee2ca JG |
695 | client_list_element->client = client; |
696 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
697 | cds_list_add(&client_list_element->node, &client_list->list); | |
698 | end_unlock: | |
699 | rcu_read_unlock(); | |
700 | end: | |
701 | if (_status) { | |
702 | *_status = status; | |
703 | } | |
704 | return ret; | |
705 | error: | |
706 | free(condition_list_element); | |
707 | free(client_list_element); | |
708 | return ret; | |
709 | } | |
710 | ||
711 | static | |
712 | int notification_thread_client_unsubscribe( | |
713 | struct notification_client *client, | |
714 | struct lttng_condition *condition, | |
715 | struct notification_thread_state *state, | |
716 | enum lttng_notification_channel_status *_status) | |
717 | { | |
718 | struct cds_lfht_iter iter; | |
719 | struct cds_lfht_node *node; | |
720 | struct notification_client_list *client_list; | |
721 | struct lttng_condition_list_element *condition_list_element, | |
722 | *condition_tmp; | |
723 | struct notification_client_list_element *client_list_element, | |
724 | *client_tmp; | |
725 | bool condition_found = false; | |
726 | enum lttng_notification_channel_status status = | |
727 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
728 | ||
729 | /* Remove the condition from the client's condition list. */ | |
730 | cds_list_for_each_entry_safe(condition_list_element, condition_tmp, | |
731 | &client->condition_list, node) { | |
732 | if (!lttng_condition_is_equal(condition_list_element->condition, | |
733 | condition)) { | |
734 | continue; | |
735 | } | |
736 | ||
737 | cds_list_del(&condition_list_element->node); | |
738 | /* | |
739 | * The caller may be iterating on the client's conditions to | |
740 | * tear down a client's connection. In this case, the condition | |
741 | * will be destroyed at the end. | |
742 | */ | |
743 | if (condition != condition_list_element->condition) { | |
744 | lttng_condition_destroy( | |
745 | condition_list_element->condition); | |
746 | } | |
747 | free(condition_list_element); | |
748 | condition_found = true; | |
749 | break; | |
750 | } | |
751 | ||
752 | if (!condition_found) { | |
753 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNKNOWN_CONDITION; | |
754 | goto end; | |
755 | } | |
756 | ||
757 | /* | |
758 | * Remove the client from the list of clients interested the trigger | |
759 | * matching the condition. | |
760 | */ | |
761 | rcu_read_lock(); | |
762 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
763 | lttng_condition_hash(condition), | |
764 | match_client_list_condition, | |
765 | condition, | |
766 | &iter); | |
767 | node = cds_lfht_iter_get_node(&iter); | |
768 | if (!node) { | |
769 | goto end_unlock; | |
770 | } | |
771 | ||
772 | client_list = caa_container_of(node, struct notification_client_list, | |
773 | notification_trigger_ht_node); | |
774 | cds_list_for_each_entry_safe(client_list_element, client_tmp, | |
775 | &client_list->list, node) { | |
776 | if (client_list_element->client->socket != client->socket) { | |
777 | continue; | |
778 | } | |
779 | cds_list_del(&client_list_element->node); | |
780 | free(client_list_element); | |
781 | break; | |
782 | } | |
783 | end_unlock: | |
784 | rcu_read_unlock(); | |
785 | end: | |
786 | lttng_condition_destroy(condition); | |
787 | if (_status) { | |
788 | *_status = status; | |
789 | } | |
790 | return 0; | |
791 | } | |
792 | ||
793 | static | |
794 | void notification_client_destroy(struct notification_client *client, | |
795 | struct notification_thread_state *state) | |
796 | { | |
797 | struct lttng_condition_list_element *condition_list_element, *tmp; | |
798 | ||
799 | if (!client) { | |
800 | return; | |
801 | } | |
802 | ||
803 | /* Release all conditions to which the client was subscribed. */ | |
804 | cds_list_for_each_entry_safe(condition_list_element, tmp, | |
805 | &client->condition_list, node) { | |
806 | (void) notification_thread_client_unsubscribe(client, | |
807 | condition_list_element->condition, state, NULL); | |
808 | } | |
809 | ||
810 | if (client->socket >= 0) { | |
811 | (void) lttcomm_close_unix_sock(client->socket); | |
812 | } | |
813 | lttng_dynamic_buffer_reset(&client->communication.inbound.buffer); | |
814 | lttng_dynamic_buffer_reset(&client->communication.outbound.buffer); | |
815 | free(client); | |
816 | } | |
817 | ||
818 | /* | |
819 | * Call with rcu_read_lock held (and hold for the lifetime of the returned | |
820 | * client pointer). | |
821 | */ | |
822 | static | |
823 | struct notification_client *get_client_from_socket(int socket, | |
824 | struct notification_thread_state *state) | |
825 | { | |
826 | struct cds_lfht_iter iter; | |
827 | struct cds_lfht_node *node; | |
828 | struct notification_client *client = NULL; | |
829 | ||
830 | cds_lfht_lookup(state->client_socket_ht, | |
831 | hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed), | |
832 | match_client, | |
833 | (void *) (unsigned long) socket, | |
834 | &iter); | |
835 | node = cds_lfht_iter_get_node(&iter); | |
836 | if (!node) { | |
837 | goto end; | |
838 | } | |
839 | ||
840 | client = caa_container_of(node, struct notification_client, | |
841 | client_socket_ht_node); | |
842 | end: | |
843 | return client; | |
844 | } | |
845 | ||
846 | static | |
847 | bool trigger_applies_to_channel(struct lttng_trigger *trigger, | |
8abe313a | 848 | struct channel_info *channel_info) |
ab0ee2ca JG |
849 | { |
850 | enum lttng_condition_status status; | |
851 | struct lttng_condition *condition; | |
852 | const char *trigger_session_name = NULL; | |
853 | const char *trigger_channel_name = NULL; | |
854 | enum lttng_domain_type trigger_domain; | |
855 | ||
856 | condition = lttng_trigger_get_condition(trigger); | |
857 | if (!condition) { | |
858 | goto fail; | |
859 | } | |
860 | ||
861 | switch (lttng_condition_get_type(condition)) { | |
862 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
863 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
864 | break; | |
865 | default: | |
866 | goto fail; | |
867 | } | |
868 | ||
869 | status = lttng_condition_buffer_usage_get_domain_type(condition, | |
870 | &trigger_domain); | |
871 | assert(status == LTTNG_CONDITION_STATUS_OK); | |
8abe313a | 872 | if (channel_info->key.domain != trigger_domain) { |
ab0ee2ca JG |
873 | goto fail; |
874 | } | |
875 | ||
876 | status = lttng_condition_buffer_usage_get_session_name( | |
877 | condition, &trigger_session_name); | |
878 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_session_name); | |
879 | ||
880 | status = lttng_condition_buffer_usage_get_channel_name( | |
881 | condition, &trigger_channel_name); | |
882 | assert((status == LTTNG_CONDITION_STATUS_OK) && trigger_channel_name); | |
883 | ||
8abe313a | 884 | if (strcmp(channel_info->session_info->name, trigger_session_name)) { |
ab0ee2ca JG |
885 | goto fail; |
886 | } | |
8abe313a | 887 | if (strcmp(channel_info->name, trigger_channel_name)) { |
ab0ee2ca JG |
888 | goto fail; |
889 | } | |
890 | ||
891 | return true; | |
892 | fail: | |
893 | return false; | |
894 | } | |
895 | ||
896 | static | |
897 | bool trigger_applies_to_client(struct lttng_trigger *trigger, | |
898 | struct notification_client *client) | |
899 | { | |
900 | bool applies = false; | |
901 | struct lttng_condition_list_element *condition_list_element; | |
902 | ||
903 | cds_list_for_each_entry(condition_list_element, &client->condition_list, | |
904 | node) { | |
905 | applies = lttng_condition_is_equal( | |
906 | condition_list_element->condition, | |
907 | lttng_trigger_get_condition(trigger)); | |
908 | if (applies) { | |
909 | break; | |
910 | } | |
911 | } | |
912 | return applies; | |
913 | } | |
914 | ||
8abe313a JG |
915 | static |
916 | int match_session(struct cds_lfht_node *node, const void *key) | |
917 | { | |
918 | const char *name = key; | |
919 | struct session_info *session_info = caa_container_of( | |
920 | node, struct session_info, sessions_ht_node); | |
921 | ||
922 | return !strcmp(session_info->name, name); | |
923 | } | |
924 | ||
925 | static | |
926 | struct session_info *find_or_create_session_info( | |
927 | struct notification_thread_state *state, | |
928 | const char *name, uid_t uid, gid_t gid) | |
929 | { | |
930 | struct session_info *session = NULL; | |
931 | struct cds_lfht_node *node; | |
932 | struct cds_lfht_iter iter; | |
933 | ||
934 | rcu_read_lock(); | |
935 | cds_lfht_lookup(state->sessions_ht, | |
936 | hash_key_str(name, lttng_ht_seed), | |
937 | match_session, | |
938 | name, | |
939 | &iter); | |
940 | node = cds_lfht_iter_get_node(&iter); | |
941 | if (node) { | |
942 | DBG("[notification-thread] Found session info of session \"%s\" (uid = %i, gid = %i)", | |
943 | name, uid, gid); | |
944 | session = caa_container_of(node, struct session_info, | |
945 | sessions_ht_node); | |
946 | assert(session->uid == uid); | |
947 | assert(session->gid == gid); | |
948 | goto end; | |
949 | } | |
950 | ||
951 | session = session_info_create(name, uid, gid); | |
952 | if (!session) { | |
953 | ERR("[notification-thread] Failed to allocation session info for session \"%s\" (uid = %i, gid = %i)", | |
954 | name, uid, gid); | |
955 | goto end; | |
956 | } | |
957 | end: | |
958 | rcu_read_unlock(); | |
959 | return session; | |
960 | } | |
961 | ||
ab0ee2ca JG |
962 | static |
963 | int handle_notification_thread_command_add_channel( | |
8abe313a JG |
964 | struct notification_thread_state *state, |
965 | const char *session_name, uid_t session_uid, gid_t session_gid, | |
966 | const char *channel_name, enum lttng_domain_type channel_domain, | |
967 | uint64_t channel_key_int, uint64_t channel_capacity, | |
968 | enum lttng_error_code *cmd_result) | |
ab0ee2ca JG |
969 | { |
970 | struct cds_list_head trigger_list; | |
8abe313a JG |
971 | struct channel_info *new_channel_info = NULL; |
972 | struct channel_key channel_key = { | |
973 | .key = channel_key_int, | |
974 | .domain = channel_domain, | |
975 | }; | |
ab0ee2ca JG |
976 | struct lttng_channel_trigger_list *channel_trigger_list = NULL; |
977 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
978 | int trigger_count = 0; | |
979 | struct cds_lfht_iter iter; | |
8abe313a | 980 | struct session_info *session_info = NULL; |
ab0ee2ca JG |
981 | |
982 | DBG("[notification-thread] Adding channel %s from session %s, channel key = %" PRIu64 " in %s domain", | |
8abe313a JG |
983 | channel_name, session_name, channel_key_int, |
984 | channel_domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
ab0ee2ca JG |
985 | |
986 | CDS_INIT_LIST_HEAD(&trigger_list); | |
987 | ||
8abe313a JG |
988 | session_info = find_or_create_session_info(state, session_name, |
989 | session_uid, session_gid); | |
990 | if (!session_info) { | |
991 | /* Allocation error or an internal error occured. */ | |
ab0ee2ca JG |
992 | goto error; |
993 | } | |
994 | ||
8abe313a JG |
995 | new_channel_info = channel_info_create(channel_name, &channel_key, |
996 | channel_capacity, session_info); | |
997 | if (!new_channel_info) { | |
998 | goto error; | |
999 | } | |
ab0ee2ca JG |
1000 | |
1001 | /* Build a list of all triggers applying to the new channel. */ | |
1002 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
1003 | node) { | |
1004 | struct lttng_trigger_list_element *new_element; | |
1005 | ||
1006 | if (!trigger_applies_to_channel(trigger_ht_element->trigger, | |
8abe313a | 1007 | new_channel_info)) { |
ab0ee2ca JG |
1008 | continue; |
1009 | } | |
1010 | ||
1011 | new_element = zmalloc(sizeof(*new_element)); | |
1012 | if (!new_element) { | |
1013 | goto error; | |
1014 | } | |
1015 | CDS_INIT_LIST_HEAD(&new_element->node); | |
1016 | new_element->trigger = trigger_ht_element->trigger; | |
1017 | cds_list_add(&new_element->node, &trigger_list); | |
1018 | trigger_count++; | |
1019 | } | |
1020 | ||
1021 | DBG("[notification-thread] Found %i triggers that apply to newly added channel", | |
1022 | trigger_count); | |
1023 | channel_trigger_list = zmalloc(sizeof(*channel_trigger_list)); | |
1024 | if (!channel_trigger_list) { | |
1025 | goto error; | |
1026 | } | |
8abe313a | 1027 | channel_trigger_list->channel_key = new_channel_info->key; |
ab0ee2ca JG |
1028 | CDS_INIT_LIST_HEAD(&channel_trigger_list->list); |
1029 | cds_lfht_node_init(&channel_trigger_list->channel_triggers_ht_node); | |
1030 | cds_list_splice(&trigger_list, &channel_trigger_list->list); | |
1031 | ||
1032 | rcu_read_lock(); | |
1033 | /* Add channel to the channel_ht which owns the channel_infos. */ | |
1034 | cds_lfht_add(state->channels_ht, | |
8abe313a | 1035 | hash_channel_key(&new_channel_info->key), |
ab0ee2ca JG |
1036 | &new_channel_info->channels_ht_node); |
1037 | /* | |
1038 | * Add the list of triggers associated with this channel to the | |
1039 | * channel_triggers_ht. | |
1040 | */ | |
1041 | cds_lfht_add(state->channel_triggers_ht, | |
8abe313a | 1042 | hash_channel_key(&new_channel_info->key), |
ab0ee2ca JG |
1043 | &channel_trigger_list->channel_triggers_ht_node); |
1044 | rcu_read_unlock(); | |
1045 | *cmd_result = LTTNG_OK; | |
1046 | return 0; | |
1047 | error: | |
ab0ee2ca | 1048 | channel_info_destroy(new_channel_info); |
8abe313a | 1049 | session_info_put(session_info); |
ab0ee2ca JG |
1050 | return 1; |
1051 | } | |
1052 | ||
1053 | static | |
1054 | int handle_notification_thread_command_remove_channel( | |
1055 | struct notification_thread_state *state, | |
1056 | uint64_t channel_key, enum lttng_domain_type domain, | |
1057 | enum lttng_error_code *cmd_result) | |
1058 | { | |
1059 | struct cds_lfht_node *node; | |
1060 | struct cds_lfht_iter iter; | |
1061 | struct lttng_channel_trigger_list *trigger_list; | |
1062 | struct lttng_trigger_list_element *trigger_list_element, *tmp; | |
1063 | struct channel_key key = { .key = channel_key, .domain = domain }; | |
1064 | struct channel_info *channel_info; | |
1065 | ||
1066 | DBG("[notification-thread] Removing channel key = %" PRIu64 " in %s domain", | |
1067 | channel_key, domain == LTTNG_DOMAIN_KERNEL ? "kernel" : "user space"); | |
1068 | ||
1069 | rcu_read_lock(); | |
1070 | ||
1071 | cds_lfht_lookup(state->channel_triggers_ht, | |
1072 | hash_channel_key(&key), | |
1073 | match_channel_trigger_list, | |
1074 | &key, | |
1075 | &iter); | |
1076 | node = cds_lfht_iter_get_node(&iter); | |
1077 | /* | |
1078 | * There is a severe internal error if we are being asked to remove a | |
1079 | * channel that doesn't exist. | |
1080 | */ | |
1081 | if (!node) { | |
1082 | ERR("[notification-thread] Channel being removed is unknown to the notification thread"); | |
1083 | goto end; | |
1084 | } | |
1085 | ||
1086 | /* Free the list of triggers associated with this channel. */ | |
1087 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
1088 | channel_triggers_ht_node); | |
1089 | cds_list_for_each_entry_safe(trigger_list_element, tmp, | |
1090 | &trigger_list->list, node) { | |
1091 | cds_list_del(&trigger_list_element->node); | |
1092 | free(trigger_list_element); | |
1093 | } | |
1094 | cds_lfht_del(state->channel_triggers_ht, node); | |
1095 | free(trigger_list); | |
1096 | ||
1097 | /* Free sampled channel state. */ | |
1098 | cds_lfht_lookup(state->channel_state_ht, | |
1099 | hash_channel_key(&key), | |
1100 | match_channel_state_sample, | |
1101 | &key, | |
1102 | &iter); | |
1103 | node = cds_lfht_iter_get_node(&iter); | |
1104 | /* | |
1105 | * This is expected to be NULL if the channel is destroyed before we | |
1106 | * received a sample. | |
1107 | */ | |
1108 | if (node) { | |
1109 | struct channel_state_sample *sample = caa_container_of(node, | |
1110 | struct channel_state_sample, | |
1111 | channel_state_ht_node); | |
1112 | ||
1113 | cds_lfht_del(state->channel_state_ht, node); | |
1114 | free(sample); | |
1115 | } | |
1116 | ||
1117 | /* Remove the channel from the channels_ht and free it. */ | |
1118 | cds_lfht_lookup(state->channels_ht, | |
1119 | hash_channel_key(&key), | |
1120 | match_channel_info, | |
1121 | &key, | |
1122 | &iter); | |
1123 | node = cds_lfht_iter_get_node(&iter); | |
1124 | assert(node); | |
1125 | channel_info = caa_container_of(node, struct channel_info, | |
1126 | channels_ht_node); | |
1127 | cds_lfht_del(state->channels_ht, node); | |
1128 | channel_info_destroy(channel_info); | |
1129 | end: | |
1130 | rcu_read_unlock(); | |
1131 | *cmd_result = LTTNG_OK; | |
1132 | return 0; | |
1133 | } | |
1134 | ||
1da26331 JG |
1135 | static |
1136 | int condition_is_supported(struct lttng_condition *condition) | |
1137 | { | |
1138 | int ret; | |
1139 | ||
1140 | switch (lttng_condition_get_type(condition)) { | |
1141 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW: | |
1142 | case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH: | |
1143 | { | |
1144 | enum lttng_domain_type domain; | |
1145 | ||
1146 | ret = lttng_condition_buffer_usage_get_domain_type(condition, | |
1147 | &domain); | |
1148 | if (ret) { | |
1149 | ret = -1; | |
1150 | goto end; | |
1151 | } | |
1152 | ||
1153 | if (domain != LTTNG_DOMAIN_KERNEL) { | |
1154 | ret = 1; | |
1155 | goto end; | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * Older kernel tracers don't expose the API to monitor their | |
1160 | * buffers. Therefore, we reject triggers that require that | |
1161 | * mechanism to be available to be evaluated. | |
1162 | */ | |
1163 | ret = kernel_supports_ring_buffer_snapshot_sample_positions( | |
1164 | kernel_tracer_fd); | |
1165 | break; | |
1166 | } | |
1167 | default: | |
1168 | ret = 1; | |
1169 | } | |
1170 | end: | |
1171 | return ret; | |
1172 | } | |
1173 | ||
ab0ee2ca JG |
1174 | /* |
1175 | * FIXME A client's credentials are not checked when registering a trigger, nor | |
1176 | * are they stored alongside with the trigger. | |
1177 | * | |
1da26331 | 1178 | * The effects of this are benign since: |
ab0ee2ca JG |
1179 | * - The client will succeed in registering the trigger, as it is valid, |
1180 | * - The trigger will, internally, be bound to the channel, | |
1181 | * - The notifications will not be sent since the client's credentials | |
1182 | * are checked against the channel at that moment. | |
1da26331 JG |
1183 | * |
1184 | * If this function returns a non-zero value, it means something is | |
50ca7858 | 1185 | * fundamentally broken and the whole subsystem/thread will be torn down. |
1da26331 JG |
1186 | * |
1187 | * If a non-fatal error occurs, just set the cmd_result to the appropriate | |
1188 | * error code. | |
ab0ee2ca JG |
1189 | */ |
1190 | static | |
1191 | int handle_notification_thread_command_register_trigger( | |
8abe313a JG |
1192 | struct notification_thread_state *state, |
1193 | struct lttng_trigger *trigger, | |
1194 | enum lttng_error_code *cmd_result) | |
ab0ee2ca JG |
1195 | { |
1196 | int ret = 0; | |
1197 | struct lttng_condition *condition; | |
1198 | struct notification_client *client; | |
1199 | struct notification_client_list *client_list = NULL; | |
1200 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1201 | struct notification_client_list_element *client_list_element, *tmp; | |
1202 | struct cds_lfht_node *node; | |
1203 | struct cds_lfht_iter iter; | |
1204 | struct channel_info *channel; | |
1205 | bool free_trigger = true; | |
1206 | ||
1207 | rcu_read_lock(); | |
1208 | ||
1209 | condition = lttng_trigger_get_condition(trigger); | |
1da26331 JG |
1210 | assert(condition); |
1211 | ||
1212 | ret = condition_is_supported(condition); | |
1213 | if (ret < 0) { | |
1214 | goto error; | |
1215 | } else if (ret == 0) { | |
1216 | *cmd_result = LTTNG_ERR_NOT_SUPPORTED; | |
1217 | goto error; | |
1218 | } else { | |
1219 | /* Feature is supported, continue. */ | |
1220 | ret = 0; | |
1221 | } | |
1222 | ||
ab0ee2ca JG |
1223 | trigger_ht_element = zmalloc(sizeof(*trigger_ht_element)); |
1224 | if (!trigger_ht_element) { | |
1225 | ret = -1; | |
1226 | goto error; | |
1227 | } | |
1228 | ||
1229 | /* Add trigger to the trigger_ht. */ | |
1230 | cds_lfht_node_init(&trigger_ht_element->node); | |
1231 | trigger_ht_element->trigger = trigger; | |
1232 | ||
1233 | node = cds_lfht_add_unique(state->triggers_ht, | |
1234 | lttng_condition_hash(condition), | |
1235 | match_condition, | |
1236 | condition, | |
1237 | &trigger_ht_element->node); | |
1238 | if (node != &trigger_ht_element->node) { | |
1239 | /* Not a fatal error, simply report it to the client. */ | |
1240 | *cmd_result = LTTNG_ERR_TRIGGER_EXISTS; | |
1241 | goto error_free_ht_element; | |
1242 | } | |
1243 | ||
1244 | /* | |
1245 | * Ownership of the trigger and of its wrapper was transfered to | |
1246 | * the triggers_ht. | |
1247 | */ | |
1248 | trigger_ht_element = NULL; | |
1249 | free_trigger = false; | |
1250 | ||
1251 | /* | |
1252 | * The rest only applies to triggers that have a "notify" action. | |
1253 | * It is not skipped as this is the only action type currently | |
1254 | * supported. | |
1255 | */ | |
1256 | client_list = zmalloc(sizeof(*client_list)); | |
1257 | if (!client_list) { | |
1258 | ret = -1; | |
1259 | goto error_free_ht_element; | |
1260 | } | |
1261 | cds_lfht_node_init(&client_list->notification_trigger_ht_node); | |
1262 | CDS_INIT_LIST_HEAD(&client_list->list); | |
1263 | client_list->trigger = trigger; | |
1264 | ||
1265 | /* Build a list of clients to which this new trigger applies. */ | |
1266 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1267 | client_socket_ht_node) { | |
1268 | if (!trigger_applies_to_client(trigger, client)) { | |
1269 | continue; | |
1270 | } | |
1271 | ||
1272 | client_list_element = zmalloc(sizeof(*client_list_element)); | |
1273 | if (!client_list_element) { | |
1274 | ret = -1; | |
1275 | goto error_free_client_list; | |
1276 | } | |
1277 | CDS_INIT_LIST_HEAD(&client_list_element->node); | |
1278 | client_list_element->client = client; | |
1279 | cds_list_add(&client_list_element->node, &client_list->list); | |
1280 | } | |
1281 | ||
1282 | cds_lfht_add(state->notification_trigger_clients_ht, | |
1283 | lttng_condition_hash(condition), | |
1284 | &client_list->notification_trigger_ht_node); | |
ab0ee2ca JG |
1285 | |
1286 | /* | |
1287 | * Add the trigger to list of triggers bound to the channels currently | |
1288 | * known. | |
1289 | */ | |
1290 | cds_lfht_for_each_entry(state->channels_ht, &iter, channel, | |
1291 | channels_ht_node) { | |
1292 | struct lttng_trigger_list_element *trigger_list_element; | |
1293 | struct lttng_channel_trigger_list *trigger_list; | |
1294 | ||
1295 | if (!trigger_applies_to_channel(trigger, channel)) { | |
1296 | continue; | |
1297 | } | |
1298 | ||
1299 | cds_lfht_lookup(state->channel_triggers_ht, | |
1300 | hash_channel_key(&channel->key), | |
1301 | match_channel_trigger_list, | |
1302 | &channel->key, | |
1303 | &iter); | |
1304 | node = cds_lfht_iter_get_node(&iter); | |
1305 | assert(node); | |
ab0ee2ca JG |
1306 | trigger_list = caa_container_of(node, |
1307 | struct lttng_channel_trigger_list, | |
1308 | channel_triggers_ht_node); | |
1309 | ||
1310 | trigger_list_element = zmalloc(sizeof(*trigger_list_element)); | |
1311 | if (!trigger_list_element) { | |
1312 | ret = -1; | |
1313 | goto error_free_client_list; | |
1314 | } | |
1315 | CDS_INIT_LIST_HEAD(&trigger_list_element->node); | |
1316 | trigger_list_element->trigger = trigger; | |
1317 | cds_list_add(&trigger_list_element->node, &trigger_list->list); | |
e4db5ace | 1318 | |
ab0ee2ca JG |
1319 | /* A trigger can only apply to one channel. */ |
1320 | break; | |
1321 | } | |
1322 | ||
2ae99f0b JG |
1323 | /* |
1324 | * Since there is nothing preventing clients from subscribing to a | |
1325 | * condition before the corresponding trigger is registered, we have | |
1326 | * to evaluate this new condition right away. | |
1327 | * | |
1328 | * At some point, we were waiting for the next "evaluation" (e.g. on | |
1329 | * reception of a channel sample) to evaluate this new condition, but | |
1330 | * that was broken. | |
1331 | * | |
1332 | * The reason it was broken is that waiting for the next sample | |
1333 | * does not allow us to properly handle transitions for edge-triggered | |
1334 | * conditions. | |
1335 | * | |
1336 | * Consider this example: when we handle a new channel sample, we | |
1337 | * evaluate each conditions twice: once with the previous state, and | |
1338 | * again with the newest state. We then use those two results to | |
1339 | * determine whether a state change happened: a condition was false and | |
1340 | * became true. If a state change happened, we have to notify clients. | |
1341 | * | |
1342 | * Now, if a client subscribes to a given notification and registers | |
1343 | * a trigger *after* that subscription, we have to make sure the | |
1344 | * condition is evaluated at this point while considering only the | |
1345 | * current state. Otherwise, the next evaluation cycle may only see | |
1346 | * that the evaluations remain the same (true for samples n-1 and n) and | |
1347 | * the client will never know that the condition has been met. | |
1348 | */ | |
1349 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1350 | &client_list->list, node) { | |
1351 | ret = evaluate_condition_for_client(trigger, condition, | |
1352 | client_list_element->client, state); | |
1353 | if (ret) { | |
1354 | goto error_free_client_list; | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | /* | |
1359 | * Client list ownership transferred to the | |
1360 | * notification_trigger_clients_ht. | |
1361 | */ | |
1362 | client_list = NULL; | |
1363 | ||
ab0ee2ca JG |
1364 | *cmd_result = LTTNG_OK; |
1365 | error_free_client_list: | |
1366 | if (client_list) { | |
1367 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1368 | &client_list->list, node) { | |
1369 | free(client_list_element); | |
1370 | } | |
1371 | free(client_list); | |
1372 | } | |
1373 | error_free_ht_element: | |
1374 | free(trigger_ht_element); | |
1375 | error: | |
1376 | if (free_trigger) { | |
1377 | struct lttng_action *action = lttng_trigger_get_action(trigger); | |
1378 | ||
1379 | lttng_condition_destroy(condition); | |
1380 | lttng_action_destroy(action); | |
1381 | lttng_trigger_destroy(trigger); | |
1382 | } | |
1383 | rcu_read_unlock(); | |
1384 | return ret; | |
1385 | } | |
1386 | ||
cc2295b5 | 1387 | static |
ab0ee2ca JG |
1388 | int handle_notification_thread_command_unregister_trigger( |
1389 | struct notification_thread_state *state, | |
1390 | struct lttng_trigger *trigger, | |
1391 | enum lttng_error_code *_cmd_reply) | |
1392 | { | |
1393 | struct cds_lfht_iter iter; | |
1394 | struct cds_lfht_node *node, *triggers_ht_node; | |
1395 | struct lttng_channel_trigger_list *trigger_list; | |
1396 | struct notification_client_list *client_list; | |
1397 | struct notification_client_list_element *client_list_element, *tmp; | |
1398 | struct lttng_trigger_ht_element *trigger_ht_element = NULL; | |
1399 | struct lttng_condition *condition = lttng_trigger_get_condition( | |
1400 | trigger); | |
1401 | struct lttng_action *action; | |
1402 | enum lttng_error_code cmd_reply; | |
1403 | ||
1404 | rcu_read_lock(); | |
1405 | ||
1406 | cds_lfht_lookup(state->triggers_ht, | |
1407 | lttng_condition_hash(condition), | |
1408 | match_condition, | |
1409 | condition, | |
1410 | &iter); | |
1411 | triggers_ht_node = cds_lfht_iter_get_node(&iter); | |
1412 | if (!triggers_ht_node) { | |
1413 | cmd_reply = LTTNG_ERR_TRIGGER_NOT_FOUND; | |
1414 | goto end; | |
1415 | } else { | |
1416 | cmd_reply = LTTNG_OK; | |
1417 | } | |
1418 | ||
1419 | /* Remove trigger from channel_triggers_ht. */ | |
1420 | cds_lfht_for_each_entry(state->channel_triggers_ht, &iter, trigger_list, | |
1421 | channel_triggers_ht_node) { | |
1422 | struct lttng_trigger_list_element *trigger_element, *tmp; | |
1423 | ||
1424 | cds_list_for_each_entry_safe(trigger_element, tmp, | |
1425 | &trigger_list->list, node) { | |
1426 | struct lttng_condition *current_condition = | |
1427 | lttng_trigger_get_condition( | |
1428 | trigger_element->trigger); | |
1429 | ||
1430 | assert(current_condition); | |
1431 | if (!lttng_condition_is_equal(condition, | |
1432 | current_condition)) { | |
1433 | continue; | |
1434 | } | |
1435 | ||
1436 | DBG("[notification-thread] Removed trigger from channel_triggers_ht"); | |
1437 | cds_list_del(&trigger_element->node); | |
e4db5ace JR |
1438 | /* A trigger can only appear once per channel */ |
1439 | break; | |
ab0ee2ca JG |
1440 | } |
1441 | } | |
1442 | ||
1443 | /* | |
1444 | * Remove and release the client list from | |
1445 | * notification_trigger_clients_ht. | |
1446 | */ | |
1447 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
1448 | lttng_condition_hash(condition), | |
1449 | match_client_list, | |
1450 | trigger, | |
1451 | &iter); | |
1452 | node = cds_lfht_iter_get_node(&iter); | |
1453 | assert(node); | |
1454 | client_list = caa_container_of(node, struct notification_client_list, | |
1455 | notification_trigger_ht_node); | |
1456 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
1457 | &client_list->list, node) { | |
1458 | free(client_list_element); | |
1459 | } | |
1460 | cds_lfht_del(state->notification_trigger_clients_ht, node); | |
1461 | free(client_list); | |
1462 | ||
1463 | /* Remove trigger from triggers_ht. */ | |
1464 | trigger_ht_element = caa_container_of(triggers_ht_node, | |
1465 | struct lttng_trigger_ht_element, node); | |
1466 | cds_lfht_del(state->triggers_ht, triggers_ht_node); | |
1467 | ||
1468 | condition = lttng_trigger_get_condition(trigger_ht_element->trigger); | |
1469 | lttng_condition_destroy(condition); | |
1470 | action = lttng_trigger_get_action(trigger_ht_element->trigger); | |
1471 | lttng_action_destroy(action); | |
1472 | lttng_trigger_destroy(trigger_ht_element->trigger); | |
1473 | free(trigger_ht_element); | |
1474 | end: | |
1475 | rcu_read_unlock(); | |
1476 | if (_cmd_reply) { | |
1477 | *_cmd_reply = cmd_reply; | |
1478 | } | |
1479 | return 0; | |
1480 | } | |
1481 | ||
1482 | /* Returns 0 on success, 1 on exit requested, negative value on error. */ | |
1483 | int handle_notification_thread_command( | |
1484 | struct notification_thread_handle *handle, | |
1485 | struct notification_thread_state *state) | |
1486 | { | |
1487 | int ret; | |
1488 | uint64_t counter; | |
1489 | struct notification_thread_command *cmd; | |
1490 | ||
8abe313a JG |
1491 | /* Read the event pipe to put it back into a quiescent state. */ |
1492 | ret = read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter, | |
1493 | sizeof(counter)); | |
ab0ee2ca JG |
1494 | if (ret == -1) { |
1495 | goto error; | |
1496 | } | |
1497 | ||
1498 | pthread_mutex_lock(&handle->cmd_queue.lock); | |
1499 | cmd = cds_list_first_entry(&handle->cmd_queue.list, | |
1500 | struct notification_thread_command, cmd_list_node); | |
1501 | switch (cmd->type) { | |
1502 | case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER: | |
1503 | DBG("[notification-thread] Received register trigger command"); | |
1504 | ret = handle_notification_thread_command_register_trigger( | |
1505 | state, cmd->parameters.trigger, | |
1506 | &cmd->reply_code); | |
1507 | break; | |
1508 | case NOTIFICATION_COMMAND_TYPE_UNREGISTER_TRIGGER: | |
1509 | DBG("[notification-thread] Received unregister trigger command"); | |
1510 | ret = handle_notification_thread_command_unregister_trigger( | |
1511 | state, cmd->parameters.trigger, | |
1512 | &cmd->reply_code); | |
1513 | break; | |
1514 | case NOTIFICATION_COMMAND_TYPE_ADD_CHANNEL: | |
1515 | DBG("[notification-thread] Received add channel command"); | |
1516 | ret = handle_notification_thread_command_add_channel( | |
8abe313a JG |
1517 | state, |
1518 | cmd->parameters.add_channel.session.name, | |
1519 | cmd->parameters.add_channel.session.uid, | |
1520 | cmd->parameters.add_channel.session.gid, | |
1521 | cmd->parameters.add_channel.channel.name, | |
1522 | cmd->parameters.add_channel.channel.domain, | |
1523 | cmd->parameters.add_channel.channel.key, | |
1524 | cmd->parameters.add_channel.channel.capacity, | |
ab0ee2ca JG |
1525 | &cmd->reply_code); |
1526 | break; | |
1527 | case NOTIFICATION_COMMAND_TYPE_REMOVE_CHANNEL: | |
1528 | DBG("[notification-thread] Received remove channel command"); | |
1529 | ret = handle_notification_thread_command_remove_channel( | |
1530 | state, cmd->parameters.remove_channel.key, | |
1531 | cmd->parameters.remove_channel.domain, | |
1532 | &cmd->reply_code); | |
1533 | break; | |
1534 | case NOTIFICATION_COMMAND_TYPE_QUIT: | |
1535 | DBG("[notification-thread] Received quit command"); | |
1536 | cmd->reply_code = LTTNG_OK; | |
1537 | ret = 1; | |
1538 | goto end; | |
1539 | default: | |
1540 | ERR("[notification-thread] Unknown internal command received"); | |
1541 | goto error_unlock; | |
1542 | } | |
1543 | ||
1544 | if (ret) { | |
1545 | goto error_unlock; | |
1546 | } | |
1547 | end: | |
1548 | cds_list_del(&cmd->cmd_list_node); | |
8ada111f | 1549 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1550 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1551 | return ret; | |
1552 | error_unlock: | |
1553 | /* Wake-up and return a fatal error to the calling thread. */ | |
8ada111f | 1554 | lttng_waiter_wake_up(&cmd->reply_waiter); |
ab0ee2ca JG |
1555 | pthread_mutex_unlock(&handle->cmd_queue.lock); |
1556 | cmd->reply_code = LTTNG_ERR_FATAL; | |
1557 | error: | |
1558 | /* Indicate a fatal error to the caller. */ | |
1559 | return -1; | |
1560 | } | |
1561 | ||
1562 | static | |
1563 | unsigned long hash_client_socket(int socket) | |
1564 | { | |
1565 | return hash_key_ulong((void *) (unsigned long) socket, lttng_ht_seed); | |
1566 | } | |
1567 | ||
1568 | static | |
1569 | int socket_set_non_blocking(int socket) | |
1570 | { | |
1571 | int ret, flags; | |
1572 | ||
1573 | /* Set the pipe as non-blocking. */ | |
1574 | ret = fcntl(socket, F_GETFL, 0); | |
1575 | if (ret == -1) { | |
1576 | PERROR("fcntl get socket flags"); | |
1577 | goto end; | |
1578 | } | |
1579 | flags = ret; | |
1580 | ||
1581 | ret = fcntl(socket, F_SETFL, flags | O_NONBLOCK); | |
1582 | if (ret == -1) { | |
1583 | PERROR("fcntl set O_NONBLOCK socket flag"); | |
1584 | goto end; | |
1585 | } | |
1586 | DBG("Client socket (fd = %i) set as non-blocking", socket); | |
1587 | end: | |
1588 | return ret; | |
1589 | } | |
1590 | ||
1591 | static | |
14fa22f8 | 1592 | int client_reset_inbound_state(struct notification_client *client) |
ab0ee2ca JG |
1593 | { |
1594 | int ret; | |
1595 | ||
1596 | ret = lttng_dynamic_buffer_set_size( | |
1597 | &client->communication.inbound.buffer, 0); | |
1598 | assert(!ret); | |
1599 | ||
1600 | client->communication.inbound.bytes_to_receive = | |
1601 | sizeof(struct lttng_notification_channel_message); | |
1602 | client->communication.inbound.msg_type = | |
1603 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN; | |
ab0ee2ca JG |
1604 | LTTNG_SOCK_SET_UID_CRED(&client->communication.inbound.creds, -1); |
1605 | LTTNG_SOCK_SET_GID_CRED(&client->communication.inbound.creds, -1); | |
14fa22f8 JG |
1606 | ret = lttng_dynamic_buffer_set_size( |
1607 | &client->communication.inbound.buffer, | |
1608 | client->communication.inbound.bytes_to_receive); | |
1609 | return ret; | |
ab0ee2ca JG |
1610 | } |
1611 | ||
1612 | int handle_notification_thread_client_connect( | |
1613 | struct notification_thread_state *state) | |
1614 | { | |
1615 | int ret; | |
1616 | struct notification_client *client; | |
1617 | ||
1618 | DBG("[notification-thread] Handling new notification channel client connection"); | |
1619 | ||
1620 | client = zmalloc(sizeof(*client)); | |
1621 | if (!client) { | |
1622 | /* Fatal error. */ | |
1623 | ret = -1; | |
1624 | goto error; | |
1625 | } | |
1626 | CDS_INIT_LIST_HEAD(&client->condition_list); | |
1627 | lttng_dynamic_buffer_init(&client->communication.inbound.buffer); | |
1628 | lttng_dynamic_buffer_init(&client->communication.outbound.buffer); | |
01ea340e | 1629 | client->communication.inbound.expect_creds = true; |
14fa22f8 JG |
1630 | ret = client_reset_inbound_state(client); |
1631 | if (ret) { | |
1632 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1633 | ret = 0; | |
1634 | goto error; | |
1635 | } | |
ab0ee2ca JG |
1636 | |
1637 | ret = lttcomm_accept_unix_sock(state->notification_channel_socket); | |
1638 | if (ret < 0) { | |
1639 | ERR("[notification-thread] Failed to accept new notification channel client connection"); | |
1640 | ret = 0; | |
1641 | goto error; | |
1642 | } | |
1643 | ||
1644 | client->socket = ret; | |
1645 | ||
1646 | ret = socket_set_non_blocking(client->socket); | |
1647 | if (ret) { | |
1648 | ERR("[notification-thread] Failed to set new notification channel client connection socket as non-blocking"); | |
1649 | goto error; | |
1650 | } | |
1651 | ||
1652 | ret = lttcomm_setsockopt_creds_unix_sock(client->socket); | |
1653 | if (ret < 0) { | |
1654 | ERR("[notification-thread] Failed to set socket options on new notification channel client socket"); | |
1655 | ret = 0; | |
1656 | goto error; | |
1657 | } | |
1658 | ||
1659 | ret = lttng_poll_add(&state->events, client->socket, | |
1660 | LPOLLIN | LPOLLERR | | |
1661 | LPOLLHUP | LPOLLRDHUP); | |
1662 | if (ret < 0) { | |
1663 | ERR("[notification-thread] Failed to add notification channel client socket to poll set"); | |
1664 | ret = 0; | |
1665 | goto error; | |
1666 | } | |
1667 | DBG("[notification-thread] Added new notification channel client socket (%i) to poll set", | |
1668 | client->socket); | |
1669 | ||
ab0ee2ca JG |
1670 | rcu_read_lock(); |
1671 | cds_lfht_add(state->client_socket_ht, | |
1672 | hash_client_socket(client->socket), | |
1673 | &client->client_socket_ht_node); | |
1674 | rcu_read_unlock(); | |
1675 | ||
1676 | return ret; | |
1677 | error: | |
1678 | notification_client_destroy(client, state); | |
1679 | return ret; | |
1680 | } | |
1681 | ||
1682 | int handle_notification_thread_client_disconnect( | |
1683 | int client_socket, | |
1684 | struct notification_thread_state *state) | |
1685 | { | |
1686 | int ret = 0; | |
1687 | struct notification_client *client; | |
1688 | ||
1689 | rcu_read_lock(); | |
1690 | DBG("[notification-thread] Closing client connection (socket fd = %i)", | |
1691 | client_socket); | |
1692 | client = get_client_from_socket(client_socket, state); | |
1693 | if (!client) { | |
1694 | /* Internal state corruption, fatal error. */ | |
1695 | ERR("[notification-thread] Unable to find client (socket fd = %i)", | |
1696 | client_socket); | |
1697 | ret = -1; | |
1698 | goto end; | |
1699 | } | |
1700 | ||
1701 | ret = lttng_poll_del(&state->events, client_socket); | |
1702 | if (ret) { | |
1703 | ERR("[notification-thread] Failed to remove client socket from poll set"); | |
1704 | } | |
1705 | cds_lfht_del(state->client_socket_ht, | |
1706 | &client->client_socket_ht_node); | |
1707 | notification_client_destroy(client, state); | |
1708 | end: | |
1709 | rcu_read_unlock(); | |
1710 | return ret; | |
1711 | } | |
1712 | ||
1713 | int handle_notification_thread_client_disconnect_all( | |
1714 | struct notification_thread_state *state) | |
1715 | { | |
1716 | struct cds_lfht_iter iter; | |
1717 | struct notification_client *client; | |
1718 | bool error_encoutered = false; | |
1719 | ||
1720 | rcu_read_lock(); | |
1721 | DBG("[notification-thread] Closing all client connections"); | |
1722 | cds_lfht_for_each_entry(state->client_socket_ht, &iter, client, | |
1723 | client_socket_ht_node) { | |
1724 | int ret; | |
1725 | ||
1726 | ret = handle_notification_thread_client_disconnect( | |
1727 | client->socket, state); | |
1728 | if (ret) { | |
1729 | error_encoutered = true; | |
1730 | } | |
1731 | } | |
1732 | rcu_read_unlock(); | |
1733 | return error_encoutered ? 1 : 0; | |
1734 | } | |
1735 | ||
1736 | int handle_notification_thread_trigger_unregister_all( | |
1737 | struct notification_thread_state *state) | |
1738 | { | |
4149ace8 | 1739 | bool error_occurred = false; |
ab0ee2ca JG |
1740 | struct cds_lfht_iter iter; |
1741 | struct lttng_trigger_ht_element *trigger_ht_element; | |
1742 | ||
1743 | cds_lfht_for_each_entry(state->triggers_ht, &iter, trigger_ht_element, | |
1744 | node) { | |
1745 | int ret = handle_notification_thread_command_unregister_trigger( | |
1746 | state, trigger_ht_element->trigger, NULL); | |
1747 | if (ret) { | |
4149ace8 | 1748 | error_occurred = true; |
ab0ee2ca JG |
1749 | } |
1750 | } | |
4149ace8 | 1751 | return error_occurred ? -1 : 0; |
ab0ee2ca JG |
1752 | } |
1753 | ||
1754 | static | |
1755 | int client_flush_outgoing_queue(struct notification_client *client, | |
1756 | struct notification_thread_state *state) | |
1757 | { | |
1758 | ssize_t ret; | |
1759 | size_t to_send_count; | |
1760 | ||
1761 | assert(client->communication.outbound.buffer.size != 0); | |
1762 | to_send_count = client->communication.outbound.buffer.size; | |
1763 | DBG("[notification-thread] Flushing client (socket fd = %i) outgoing queue", | |
1764 | client->socket); | |
1765 | ||
1766 | ret = lttcomm_send_unix_sock_non_block(client->socket, | |
1767 | client->communication.outbound.buffer.data, | |
1768 | to_send_count); | |
1769 | if ((ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) || | |
1770 | (ret > 0 && ret < to_send_count)) { | |
1771 | DBG("[notification-thread] Client (socket fd = %i) outgoing queue could not be completely flushed", | |
1772 | client->socket); | |
1773 | to_send_count -= max(ret, 0); | |
1774 | ||
1775 | memcpy(client->communication.outbound.buffer.data, | |
1776 | client->communication.outbound.buffer.data + | |
1777 | client->communication.outbound.buffer.size - to_send_count, | |
1778 | to_send_count); | |
1779 | ret = lttng_dynamic_buffer_set_size( | |
1780 | &client->communication.outbound.buffer, | |
1781 | to_send_count); | |
1782 | if (ret) { | |
1783 | goto error; | |
1784 | } | |
1785 | ||
1786 | /* | |
1787 | * We want to be notified whenever there is buffer space | |
1788 | * available to send the rest of the payload. | |
1789 | */ | |
1790 | ret = lttng_poll_mod(&state->events, client->socket, | |
1791 | CLIENT_POLL_MASK_IN_OUT); | |
1792 | if (ret) { | |
1793 | goto error; | |
1794 | } | |
1795 | } else if (ret < 0) { | |
1796 | /* Generic error, disconnect the client. */ | |
1797 | ERR("[notification-thread] Failed to send flush outgoing queue, disconnecting client (socket fd = %i)", | |
1798 | client->socket); | |
1799 | ret = handle_notification_thread_client_disconnect( | |
1800 | client->socket, state); | |
1801 | if (ret) { | |
1802 | goto error; | |
1803 | } | |
1804 | } else { | |
1805 | /* No error and flushed the queue completely. */ | |
1806 | ret = lttng_dynamic_buffer_set_size( | |
1807 | &client->communication.outbound.buffer, 0); | |
1808 | if (ret) { | |
1809 | goto error; | |
1810 | } | |
1811 | ret = lttng_poll_mod(&state->events, client->socket, | |
1812 | CLIENT_POLL_MASK_IN); | |
1813 | if (ret) { | |
1814 | goto error; | |
1815 | } | |
1816 | ||
1817 | client->communication.outbound.queued_command_reply = false; | |
1818 | client->communication.outbound.dropped_notification = false; | |
1819 | } | |
1820 | ||
1821 | return 0; | |
1822 | error: | |
1823 | return -1; | |
1824 | } | |
1825 | ||
1826 | static | |
1827 | int client_send_command_reply(struct notification_client *client, | |
1828 | struct notification_thread_state *state, | |
1829 | enum lttng_notification_channel_status status) | |
1830 | { | |
1831 | int ret; | |
1832 | struct lttng_notification_channel_command_reply reply = { | |
1833 | .status = (int8_t) status, | |
1834 | }; | |
1835 | struct lttng_notification_channel_message msg = { | |
1836 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY, | |
1837 | .size = sizeof(reply), | |
1838 | }; | |
1839 | char buffer[sizeof(msg) + sizeof(reply)]; | |
1840 | ||
1841 | if (client->communication.outbound.queued_command_reply) { | |
1842 | /* Protocol error. */ | |
1843 | goto error; | |
1844 | } | |
1845 | ||
1846 | memcpy(buffer, &msg, sizeof(msg)); | |
1847 | memcpy(buffer + sizeof(msg), &reply, sizeof(reply)); | |
1848 | DBG("[notification-thread] Send command reply (%i)", (int) status); | |
1849 | ||
1850 | /* Enqueue buffer to outgoing queue and flush it. */ | |
1851 | ret = lttng_dynamic_buffer_append( | |
1852 | &client->communication.outbound.buffer, | |
1853 | buffer, sizeof(buffer)); | |
1854 | if (ret) { | |
1855 | goto error; | |
1856 | } | |
1857 | ||
1858 | ret = client_flush_outgoing_queue(client, state); | |
1859 | if (ret) { | |
1860 | goto error; | |
1861 | } | |
1862 | ||
1863 | if (client->communication.outbound.buffer.size != 0) { | |
1864 | /* Queue could not be emptied. */ | |
1865 | client->communication.outbound.queued_command_reply = true; | |
1866 | } | |
1867 | ||
1868 | return 0; | |
1869 | error: | |
1870 | return -1; | |
1871 | } | |
1872 | ||
1873 | static | |
1874 | int client_dispatch_message(struct notification_client *client, | |
1875 | struct notification_thread_state *state) | |
1876 | { | |
1877 | int ret = 0; | |
1878 | ||
1879 | if (client->communication.inbound.msg_type != | |
1880 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE && | |
1881 | client->communication.inbound.msg_type != | |
1882 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN && | |
1883 | !client->validated) { | |
1884 | WARN("[notification-thread] client attempted a command before handshake"); | |
1885 | ret = -1; | |
1886 | goto end; | |
1887 | } | |
1888 | ||
1889 | switch (client->communication.inbound.msg_type) { | |
1890 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNKNOWN: | |
1891 | { | |
1892 | /* | |
1893 | * Receiving message header. The function will be called again | |
1894 | * once the rest of the message as been received and can be | |
1895 | * interpreted. | |
1896 | */ | |
1897 | const struct lttng_notification_channel_message *msg; | |
1898 | ||
1899 | assert(sizeof(*msg) == | |
1900 | client->communication.inbound.buffer.size); | |
1901 | msg = (const struct lttng_notification_channel_message *) | |
1902 | client->communication.inbound.buffer.data; | |
1903 | ||
1904 | if (msg->size == 0 || msg->size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
1905 | ERR("[notification-thread] Invalid notification channel message: length = %u", msg->size); | |
1906 | ret = -1; | |
1907 | goto end; | |
1908 | } | |
1909 | ||
1910 | switch (msg->type) { | |
1911 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
1912 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
1913 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1914 | break; | |
1915 | default: | |
1916 | ret = -1; | |
1917 | ERR("[notification-thread] Invalid notification channel message: unexpected message type"); | |
1918 | goto end; | |
1919 | } | |
1920 | ||
1921 | client->communication.inbound.bytes_to_receive = msg->size; | |
1922 | client->communication.inbound.msg_type = | |
1923 | (enum lttng_notification_channel_message_type) msg->type; | |
ab0ee2ca | 1924 | ret = lttng_dynamic_buffer_set_size( |
14fa22f8 | 1925 | &client->communication.inbound.buffer, msg->size); |
ab0ee2ca JG |
1926 | if (ret) { |
1927 | goto end; | |
1928 | } | |
1929 | break; | |
1930 | } | |
1931 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
1932 | { | |
1933 | struct lttng_notification_channel_command_handshake *handshake_client; | |
1934 | struct lttng_notification_channel_command_handshake handshake_reply = { | |
1935 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
1936 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
1937 | }; | |
1938 | struct lttng_notification_channel_message msg_header = { | |
1939 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
1940 | .size = sizeof(handshake_reply), | |
1941 | }; | |
1942 | enum lttng_notification_channel_status status = | |
1943 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
1944 | char send_buffer[sizeof(msg_header) + sizeof(handshake_reply)]; | |
1945 | ||
1946 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
1947 | memcpy(send_buffer + sizeof(msg_header), &handshake_reply, | |
1948 | sizeof(handshake_reply)); | |
1949 | ||
1950 | handshake_client = | |
1951 | (struct lttng_notification_channel_command_handshake *) | |
1952 | client->communication.inbound.buffer.data; | |
47a32869 | 1953 | client->major = handshake_client->major; |
ab0ee2ca JG |
1954 | client->minor = handshake_client->minor; |
1955 | if (!client->communication.inbound.creds_received) { | |
1956 | ERR("[notification-thread] No credentials received from client"); | |
1957 | ret = -1; | |
1958 | goto end; | |
1959 | } | |
1960 | ||
1961 | client->uid = LTTNG_SOCK_GET_UID_CRED( | |
1962 | &client->communication.inbound.creds); | |
1963 | client->gid = LTTNG_SOCK_GET_GID_CRED( | |
1964 | &client->communication.inbound.creds); | |
1965 | DBG("[notification-thread] Received handshake from client (uid = %u, gid = %u) with version %i.%i", | |
1966 | client->uid, client->gid, (int) client->major, | |
1967 | (int) client->minor); | |
1968 | ||
1969 | if (handshake_client->major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
1970 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_UNSUPPORTED_VERSION; | |
1971 | } | |
1972 | ||
1973 | ret = lttng_dynamic_buffer_append(&client->communication.outbound.buffer, | |
1974 | send_buffer, sizeof(send_buffer)); | |
1975 | if (ret) { | |
1976 | ERR("[notification-thread] Failed to send protocol version to notification channel client"); | |
1977 | goto end; | |
1978 | } | |
1979 | ||
1980 | ret = client_flush_outgoing_queue(client, state); | |
1981 | if (ret) { | |
1982 | goto end; | |
1983 | } | |
1984 | ||
1985 | ret = client_send_command_reply(client, state, status); | |
1986 | if (ret) { | |
1987 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
1988 | goto end; | |
1989 | } | |
1990 | ||
1991 | /* Set reception state to receive the next message header. */ | |
14fa22f8 JG |
1992 | ret = client_reset_inbound_state(client); |
1993 | if (ret) { | |
1994 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
1995 | goto end; | |
1996 | } | |
ab0ee2ca JG |
1997 | client->validated = true; |
1998 | break; | |
1999 | } | |
2000 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE: | |
2001 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE: | |
2002 | { | |
2003 | struct lttng_condition *condition; | |
2004 | enum lttng_notification_channel_status status = | |
2005 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
2006 | const struct lttng_buffer_view condition_view = | |
2007 | lttng_buffer_view_from_dynamic_buffer( | |
2008 | &client->communication.inbound.buffer, | |
2009 | 0, -1); | |
2010 | size_t expected_condition_size = | |
2011 | client->communication.inbound.buffer.size; | |
2012 | ||
2013 | ret = lttng_condition_create_from_buffer(&condition_view, | |
2014 | &condition); | |
2015 | if (ret != expected_condition_size) { | |
2016 | ERR("[notification-thread] Malformed condition received from client"); | |
2017 | goto end; | |
2018 | } | |
2019 | ||
2020 | if (client->communication.inbound.msg_type == | |
2021 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) { | |
ab0ee2ca JG |
2022 | ret = notification_thread_client_subscribe(client, |
2023 | condition, state, &status); | |
2024 | } else { | |
2025 | ret = notification_thread_client_unsubscribe(client, | |
2026 | condition, state, &status); | |
2027 | } | |
2028 | if (ret) { | |
2029 | goto end; | |
2030 | } | |
2031 | ||
2032 | ret = client_send_command_reply(client, state, status); | |
2033 | if (ret) { | |
2034 | ERR("[notification-thread] Failed to send reply to notification channel client"); | |
2035 | goto end; | |
2036 | } | |
2037 | ||
2038 | /* Set reception state to receive the next message header. */ | |
14fa22f8 JG |
2039 | ret = client_reset_inbound_state(client); |
2040 | if (ret) { | |
2041 | ERR("[notification-thread] Failed to reset client communication's inbound state"); | |
2042 | goto end; | |
2043 | } | |
ab0ee2ca JG |
2044 | break; |
2045 | } | |
2046 | default: | |
2047 | abort(); | |
2048 | } | |
2049 | end: | |
2050 | return ret; | |
2051 | } | |
2052 | ||
2053 | /* Incoming data from client. */ | |
2054 | int handle_notification_thread_client_in( | |
2055 | struct notification_thread_state *state, int socket) | |
2056 | { | |
14fa22f8 | 2057 | int ret = 0; |
ab0ee2ca JG |
2058 | struct notification_client *client; |
2059 | ssize_t recv_ret; | |
2060 | size_t offset; | |
2061 | ||
2062 | client = get_client_from_socket(socket, state); | |
2063 | if (!client) { | |
2064 | /* Internal error, abort. */ | |
2065 | ret = -1; | |
2066 | goto end; | |
2067 | } | |
2068 | ||
14fa22f8 JG |
2069 | offset = client->communication.inbound.buffer.size - |
2070 | client->communication.inbound.bytes_to_receive; | |
01ea340e | 2071 | if (client->communication.inbound.expect_creds) { |
ab0ee2ca JG |
2072 | recv_ret = lttcomm_recv_creds_unix_sock(socket, |
2073 | client->communication.inbound.buffer.data + offset, | |
2074 | client->communication.inbound.bytes_to_receive, | |
2075 | &client->communication.inbound.creds); | |
2076 | if (recv_ret > 0) { | |
01ea340e | 2077 | client->communication.inbound.expect_creds = false; |
ab0ee2ca JG |
2078 | client->communication.inbound.creds_received = true; |
2079 | } | |
2080 | } else { | |
2081 | recv_ret = lttcomm_recv_unix_sock_non_block(socket, | |
2082 | client->communication.inbound.buffer.data + offset, | |
2083 | client->communication.inbound.bytes_to_receive); | |
2084 | } | |
2085 | if (recv_ret < 0) { | |
2086 | goto error_disconnect_client; | |
2087 | } | |
2088 | ||
2089 | client->communication.inbound.bytes_to_receive -= recv_ret; | |
ab0ee2ca JG |
2090 | if (client->communication.inbound.bytes_to_receive == 0) { |
2091 | ret = client_dispatch_message(client, state); | |
2092 | if (ret) { | |
2093 | /* | |
2094 | * Only returns an error if this client must be | |
2095 | * disconnected. | |
2096 | */ | |
2097 | goto error_disconnect_client; | |
2098 | } | |
2099 | } else { | |
2100 | goto end; | |
2101 | } | |
2102 | end: | |
2103 | return ret; | |
2104 | error_disconnect_client: | |
2105 | ret = handle_notification_thread_client_disconnect(socket, state); | |
2106 | return ret; | |
2107 | } | |
2108 | ||
2109 | /* Client ready to receive outgoing data. */ | |
2110 | int handle_notification_thread_client_out( | |
2111 | struct notification_thread_state *state, int socket) | |
2112 | { | |
2113 | int ret; | |
2114 | struct notification_client *client; | |
2115 | ||
2116 | client = get_client_from_socket(socket, state); | |
2117 | if (!client) { | |
2118 | /* Internal error, abort. */ | |
2119 | ret = -1; | |
2120 | goto end; | |
2121 | } | |
2122 | ||
2123 | ret = client_flush_outgoing_queue(client, state); | |
2124 | if (ret) { | |
2125 | goto end; | |
2126 | } | |
2127 | end: | |
2128 | return ret; | |
2129 | } | |
2130 | ||
2131 | static | |
2132 | bool evaluate_buffer_usage_condition(struct lttng_condition *condition, | |
2133 | struct channel_state_sample *sample, uint64_t buffer_capacity) | |
2134 | { | |
2135 | bool result = false; | |
2136 | uint64_t threshold; | |
2137 | enum lttng_condition_type condition_type; | |
2138 | struct lttng_condition_buffer_usage *use_condition = container_of( | |
2139 | condition, struct lttng_condition_buffer_usage, | |
2140 | parent); | |
2141 | ||
2142 | if (!sample) { | |
2143 | goto end; | |
2144 | } | |
2145 | ||
2146 | if (use_condition->threshold_bytes.set) { | |
2147 | threshold = use_condition->threshold_bytes.value; | |
2148 | } else { | |
2149 | /* | |
2150 | * Threshold was expressed as a ratio. | |
2151 | * | |
2152 | * TODO the threshold (in bytes) of conditions expressed | |
2153 | * as a ratio of total buffer size could be cached to | |
2154 | * forego this double-multiplication or it could be performed | |
2155 | * as fixed-point math. | |
2156 | * | |
2157 | * Note that caching should accomodate the case where the | |
2158 | * condition applies to multiple channels (i.e. don't assume | |
2159 | * that all channels matching my_chann* have the same size...) | |
2160 | */ | |
2161 | threshold = (uint64_t) (use_condition->threshold_ratio.value * | |
2162 | (double) buffer_capacity); | |
2163 | } | |
2164 | ||
2165 | condition_type = lttng_condition_get_type(condition); | |
2166 | if (condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW) { | |
2167 | DBG("[notification-thread] Low buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
2168 | threshold, sample->highest_usage); | |
2169 | ||
2170 | /* | |
2171 | * The low condition should only be triggered once _all_ of the | |
2172 | * streams in a channel have gone below the "low" threshold. | |
2173 | */ | |
2174 | if (sample->highest_usage <= threshold) { | |
2175 | result = true; | |
2176 | } | |
2177 | } else { | |
2178 | DBG("[notification-thread] High buffer usage condition being evaluated: threshold = %" PRIu64 ", highest usage = %" PRIu64, | |
2179 | threshold, sample->highest_usage); | |
2180 | ||
2181 | /* | |
2182 | * For high buffer usage scenarios, we want to trigger whenever | |
2183 | * _any_ of the streams has reached the "high" threshold. | |
2184 | */ | |
2185 | if (sample->highest_usage >= threshold) { | |
2186 | result = true; | |
2187 | } | |
2188 | } | |
2189 | end: | |
2190 | return result; | |
2191 | } | |
2192 | ||
2193 | static | |
2194 | int evaluate_condition(struct lttng_condition *condition, | |
2195 | struct lttng_evaluation **evaluation, | |
2196 | struct notification_thread_state *state, | |
2197 | struct channel_state_sample *previous_sample, | |
2198 | struct channel_state_sample *latest_sample, | |
2199 | uint64_t buffer_capacity) | |
2200 | { | |
2201 | int ret = 0; | |
2202 | enum lttng_condition_type condition_type; | |
2203 | bool previous_sample_result; | |
2204 | bool latest_sample_result; | |
2205 | ||
2206 | condition_type = lttng_condition_get_type(condition); | |
2207 | /* No other condition type supported for the moment. */ | |
2208 | assert(condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW || | |
2209 | condition_type == LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH); | |
2210 | ||
2211 | previous_sample_result = evaluate_buffer_usage_condition(condition, | |
2212 | previous_sample, buffer_capacity); | |
2213 | latest_sample_result = evaluate_buffer_usage_condition(condition, | |
2214 | latest_sample, buffer_capacity); | |
2215 | ||
2216 | if (!latest_sample_result || | |
2217 | (previous_sample_result == latest_sample_result)) { | |
2218 | /* | |
2219 | * Only trigger on a condition evaluation transition. | |
2220 | * | |
2221 | * NOTE: This edge-triggered logic may not be appropriate for | |
2222 | * future condition types. | |
2223 | */ | |
2224 | goto end; | |
2225 | } | |
2226 | ||
2227 | if (evaluation && latest_sample_result) { | |
2228 | *evaluation = lttng_evaluation_buffer_usage_create( | |
2229 | condition_type, | |
2230 | latest_sample->highest_usage, | |
2231 | buffer_capacity); | |
2232 | if (!*evaluation) { | |
2233 | ret = -1; | |
2234 | goto end; | |
2235 | } | |
2236 | } | |
2237 | end: | |
2238 | return ret; | |
2239 | } | |
2240 | ||
2241 | static | |
2242 | int client_enqueue_dropped_notification(struct notification_client *client, | |
2243 | struct notification_thread_state *state) | |
2244 | { | |
2245 | int ret; | |
2246 | struct lttng_notification_channel_message msg = { | |
2247 | .type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED, | |
2248 | .size = 0, | |
2249 | }; | |
2250 | ||
2251 | ret = lttng_dynamic_buffer_append( | |
2252 | &client->communication.outbound.buffer, &msg, | |
2253 | sizeof(msg)); | |
2254 | return ret; | |
2255 | } | |
2256 | ||
2257 | static | |
2258 | int send_evaluation_to_clients(struct lttng_trigger *trigger, | |
2259 | struct lttng_evaluation *evaluation, | |
2260 | struct notification_client_list* client_list, | |
2261 | struct notification_thread_state *state, | |
2262 | uid_t channel_uid, gid_t channel_gid) | |
2263 | { | |
2264 | int ret = 0; | |
2265 | struct lttng_dynamic_buffer msg_buffer; | |
2266 | struct notification_client_list_element *client_list_element, *tmp; | |
2267 | struct lttng_notification *notification; | |
2268 | struct lttng_condition *condition; | |
2269 | ssize_t expected_notification_size, notification_size; | |
2270 | struct lttng_notification_channel_message msg; | |
2271 | ||
2272 | lttng_dynamic_buffer_init(&msg_buffer); | |
2273 | ||
2274 | condition = lttng_trigger_get_condition(trigger); | |
2275 | assert(condition); | |
2276 | ||
2277 | notification = lttng_notification_create(condition, evaluation); | |
2278 | if (!notification) { | |
2279 | ret = -1; | |
2280 | goto end; | |
2281 | } | |
2282 | ||
2283 | expected_notification_size = lttng_notification_serialize(notification, | |
2284 | NULL); | |
2285 | if (expected_notification_size < 0) { | |
2286 | ERR("[notification-thread] Failed to get size of serialized notification"); | |
2287 | ret = -1; | |
2288 | goto end; | |
2289 | } | |
2290 | ||
2291 | msg.type = (int8_t) LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION; | |
2292 | msg.size = (uint32_t) expected_notification_size; | |
2293 | ret = lttng_dynamic_buffer_append(&msg_buffer, &msg, sizeof(msg)); | |
2294 | if (ret) { | |
2295 | goto end; | |
2296 | } | |
2297 | ||
2298 | ret = lttng_dynamic_buffer_set_size(&msg_buffer, | |
2299 | msg_buffer.size + expected_notification_size); | |
2300 | if (ret) { | |
2301 | goto end; | |
2302 | } | |
2303 | ||
2304 | notification_size = lttng_notification_serialize(notification, | |
2305 | msg_buffer.data + sizeof(msg)); | |
2306 | if (notification_size != expected_notification_size) { | |
2307 | ERR("[notification-thread] Failed to serialize notification"); | |
2308 | ret = -1; | |
2309 | goto end; | |
2310 | } | |
2311 | ||
2312 | cds_list_for_each_entry_safe(client_list_element, tmp, | |
2313 | &client_list->list, node) { | |
2314 | struct notification_client *client = | |
2315 | client_list_element->client; | |
2316 | ||
2317 | if (client->uid != channel_uid && client->gid != channel_gid && | |
2318 | client->uid != 0) { | |
2319 | /* Client is not allowed to monitor this channel. */ | |
2320 | DBG("[notification-thread] Skipping client at it does not have the permission to receive notification for this channel"); | |
2321 | continue; | |
2322 | } | |
2323 | ||
2324 | DBG("[notification-thread] Sending notification to client (fd = %i, %zu bytes)", | |
2325 | client->socket, msg_buffer.size); | |
2326 | if (client->communication.outbound.buffer.size) { | |
2327 | /* | |
2328 | * Outgoing data is already buffered for this client; | |
2329 | * drop the notification and enqueue a "dropped | |
2330 | * notification" message if this is the first dropped | |
2331 | * notification since the socket spilled-over to the | |
2332 | * queue. | |
2333 | */ | |
2334 | DBG("[notification-thread] Dropping notification addressed to client (socket fd = %i)", | |
2335 | client->socket); | |
2336 | if (!client->communication.outbound.dropped_notification) { | |
2337 | client->communication.outbound.dropped_notification = true; | |
2338 | ret = client_enqueue_dropped_notification( | |
2339 | client, state); | |
2340 | if (ret) { | |
2341 | goto end; | |
2342 | } | |
2343 | } | |
2344 | continue; | |
2345 | } | |
2346 | ||
2347 | ret = lttng_dynamic_buffer_append_buffer( | |
2348 | &client->communication.outbound.buffer, | |
2349 | &msg_buffer); | |
2350 | if (ret) { | |
2351 | goto end; | |
2352 | } | |
2353 | ||
2354 | ret = client_flush_outgoing_queue(client, state); | |
2355 | if (ret) { | |
2356 | goto end; | |
2357 | } | |
2358 | } | |
2359 | ret = 0; | |
2360 | end: | |
2361 | lttng_notification_destroy(notification); | |
2362 | lttng_dynamic_buffer_reset(&msg_buffer); | |
2363 | return ret; | |
2364 | } | |
2365 | ||
2366 | int handle_notification_thread_channel_sample( | |
2367 | struct notification_thread_state *state, int pipe, | |
2368 | enum lttng_domain_type domain) | |
2369 | { | |
2370 | int ret = 0; | |
2371 | struct lttcomm_consumer_channel_monitor_msg sample_msg; | |
2372 | struct channel_state_sample previous_sample, latest_sample; | |
2373 | struct channel_info *channel_info; | |
2374 | struct cds_lfht_node *node; | |
2375 | struct cds_lfht_iter iter; | |
2376 | struct lttng_channel_trigger_list *trigger_list; | |
2377 | struct lttng_trigger_list_element *trigger_list_element; | |
2378 | bool previous_sample_available = false; | |
2379 | ||
2380 | /* | |
2381 | * The monitoring pipe only holds messages smaller than PIPE_BUF, | |
2382 | * ensuring that read/write of sampling messages are atomic. | |
2383 | */ | |
7c2551ef | 2384 | ret = lttng_read(pipe, &sample_msg, sizeof(sample_msg)); |
ab0ee2ca JG |
2385 | if (ret != sizeof(sample_msg)) { |
2386 | ERR("[notification-thread] Failed to read from monitoring pipe (fd = %i)", | |
2387 | pipe); | |
2388 | ret = -1; | |
2389 | goto end; | |
2390 | } | |
2391 | ||
2392 | ret = 0; | |
2393 | latest_sample.key.key = sample_msg.key; | |
2394 | latest_sample.key.domain = domain; | |
2395 | latest_sample.highest_usage = sample_msg.highest; | |
2396 | latest_sample.lowest_usage = sample_msg.lowest; | |
2397 | ||
2398 | rcu_read_lock(); | |
2399 | ||
2400 | /* Retrieve the channel's informations */ | |
2401 | cds_lfht_lookup(state->channels_ht, | |
2402 | hash_channel_key(&latest_sample.key), | |
2403 | match_channel_info, | |
2404 | &latest_sample.key, | |
2405 | &iter); | |
2406 | node = cds_lfht_iter_get_node(&iter); | |
2407 | if (!node) { | |
2408 | /* | |
2409 | * Not an error since the consumer can push a sample to the pipe | |
2410 | * and the rest of the session daemon could notify us of the | |
2411 | * channel's destruction before we get a chance to process that | |
2412 | * sample. | |
2413 | */ | |
2414 | DBG("[notification-thread] Received a sample for an unknown channel from consumerd, key = %" PRIu64 " in %s domain", | |
2415 | latest_sample.key.key, | |
2416 | domain == LTTNG_DOMAIN_KERNEL ? "kernel" : | |
2417 | "user space"); | |
2418 | goto end_unlock; | |
2419 | } | |
2420 | channel_info = caa_container_of(node, struct channel_info, | |
2421 | channels_ht_node); | |
2422 | DBG("[notification-thread] Handling channel sample for channel %s (key = %" PRIu64 ") in session %s (highest usage = %" PRIu64 ", lowest usage = %" PRIu64")", | |
8abe313a | 2423 | channel_info->name, |
ab0ee2ca | 2424 | latest_sample.key.key, |
8abe313a | 2425 | channel_info->session_info->name, |
ab0ee2ca JG |
2426 | latest_sample.highest_usage, |
2427 | latest_sample.lowest_usage); | |
2428 | ||
2429 | /* Retrieve the channel's last sample, if it exists, and update it. */ | |
2430 | cds_lfht_lookup(state->channel_state_ht, | |
2431 | hash_channel_key(&latest_sample.key), | |
2432 | match_channel_state_sample, | |
2433 | &latest_sample.key, | |
2434 | &iter); | |
2435 | node = cds_lfht_iter_get_node(&iter); | |
2436 | if (node) { | |
2437 | struct channel_state_sample *stored_sample; | |
2438 | ||
2439 | /* Update the sample stored. */ | |
2440 | stored_sample = caa_container_of(node, | |
2441 | struct channel_state_sample, | |
2442 | channel_state_ht_node); | |
2443 | memcpy(&previous_sample, stored_sample, | |
2444 | sizeof(previous_sample)); | |
2445 | stored_sample->highest_usage = latest_sample.highest_usage; | |
2446 | stored_sample->lowest_usage = latest_sample.lowest_usage; | |
2447 | previous_sample_available = true; | |
2448 | } else { | |
2449 | /* | |
2450 | * This is the channel's first sample, allocate space for and | |
2451 | * store the new sample. | |
2452 | */ | |
2453 | struct channel_state_sample *stored_sample; | |
2454 | ||
2455 | stored_sample = zmalloc(sizeof(*stored_sample)); | |
2456 | if (!stored_sample) { | |
2457 | ret = -1; | |
2458 | goto end_unlock; | |
2459 | } | |
2460 | ||
2461 | memcpy(stored_sample, &latest_sample, sizeof(*stored_sample)); | |
2462 | cds_lfht_node_init(&stored_sample->channel_state_ht_node); | |
2463 | cds_lfht_add(state->channel_state_ht, | |
2464 | hash_channel_key(&stored_sample->key), | |
2465 | &stored_sample->channel_state_ht_node); | |
2466 | } | |
2467 | ||
2468 | /* Find triggers associated with this channel. */ | |
2469 | cds_lfht_lookup(state->channel_triggers_ht, | |
2470 | hash_channel_key(&latest_sample.key), | |
2471 | match_channel_trigger_list, | |
2472 | &latest_sample.key, | |
2473 | &iter); | |
2474 | node = cds_lfht_iter_get_node(&iter); | |
2475 | if (!node) { | |
2476 | goto end_unlock; | |
2477 | } | |
2478 | ||
2479 | trigger_list = caa_container_of(node, struct lttng_channel_trigger_list, | |
2480 | channel_triggers_ht_node); | |
2481 | cds_list_for_each_entry(trigger_list_element, &trigger_list->list, | |
2482 | node) { | |
2483 | struct lttng_condition *condition; | |
2484 | struct lttng_action *action; | |
2485 | struct lttng_trigger *trigger; | |
2486 | struct notification_client_list *client_list; | |
2487 | struct lttng_evaluation *evaluation = NULL; | |
2488 | ||
2489 | trigger = trigger_list_element->trigger; | |
2490 | condition = lttng_trigger_get_condition(trigger); | |
2491 | assert(condition); | |
2492 | action = lttng_trigger_get_action(trigger); | |
2493 | ||
2494 | /* Notify actions are the only type currently supported. */ | |
2495 | assert(lttng_action_get_type(action) == | |
2496 | LTTNG_ACTION_TYPE_NOTIFY); | |
2497 | ||
2498 | /* | |
2499 | * Check if any client is subscribed to the result of this | |
2500 | * evaluation. | |
2501 | */ | |
2502 | cds_lfht_lookup(state->notification_trigger_clients_ht, | |
2503 | lttng_condition_hash(condition), | |
2504 | match_client_list, | |
2505 | trigger, | |
2506 | &iter); | |
2507 | node = cds_lfht_iter_get_node(&iter); | |
2508 | assert(node); | |
2509 | ||
2510 | client_list = caa_container_of(node, | |
2511 | struct notification_client_list, | |
2512 | notification_trigger_ht_node); | |
2513 | if (cds_list_empty(&client_list->list)) { | |
2514 | /* | |
2515 | * No clients interested in the evaluation's result, | |
2516 | * skip it. | |
2517 | */ | |
2518 | continue; | |
2519 | } | |
2520 | ||
2521 | ret = evaluate_condition(condition, &evaluation, state, | |
2522 | previous_sample_available ? &previous_sample : NULL, | |
2523 | &latest_sample, channel_info->capacity); | |
2524 | if (ret) { | |
2525 | goto end_unlock; | |
2526 | } | |
2527 | ||
2528 | if (!evaluation) { | |
2529 | continue; | |
2530 | } | |
2531 | ||
2532 | /* Dispatch evaluation result to all clients. */ | |
2533 | ret = send_evaluation_to_clients(trigger_list_element->trigger, | |
2534 | evaluation, client_list, state, | |
8abe313a JG |
2535 | channel_info->session_info->uid, |
2536 | channel_info->session_info->gid); | |
2537 | lttng_evaluation_destroy(evaluation); | |
ab0ee2ca JG |
2538 | if (ret) { |
2539 | goto end_unlock; | |
2540 | } | |
2541 | } | |
2542 | end_unlock: | |
2543 | rcu_read_unlock(); | |
2544 | end: | |
2545 | return ret; | |
2546 | } |