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a58c490f JG |
1 | /* |
2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This library 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 Lesser General Public License | |
11 | * for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Lesser General Public License | |
14 | * along with this library; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
18 | #include <lttng/notification/notification-internal.h> | |
19 | #include <lttng/notification/channel-internal.h> | |
20 | #include <lttng/condition/condition-internal.h> | |
21 | #include <lttng/endpoint.h> | |
22 | #include <common/defaults.h> | |
23 | #include <common/error.h> | |
24 | #include <common/dynamic-buffer.h> | |
25 | #include <common/utils.h> | |
26 | #include <common/defaults.h> | |
27 | #include <assert.h> | |
28 | #include "lttng-ctl-helper.h" | |
1d757b1c JG |
29 | #include <sys/select.h> |
30 | #include <sys/time.h> | |
a58c490f JG |
31 | |
32 | static | |
33 | int handshake(struct lttng_notification_channel *channel); | |
34 | ||
35 | /* | |
36 | * Populates the reception buffer with the next complete message. | |
1d757b1c | 37 | * The caller must acquire the channel's lock. |
a58c490f JG |
38 | */ |
39 | static | |
40 | int receive_message(struct lttng_notification_channel *channel) | |
41 | { | |
42 | ssize_t ret; | |
43 | struct lttng_notification_channel_message msg; | |
44 | ||
1d757b1c JG |
45 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
46 | ret = -1; | |
47 | goto end; | |
a58c490f JG |
48 | } |
49 | ||
50 | ret = lttcomm_recv_unix_sock(channel->socket, &msg, sizeof(msg)); | |
51 | if (ret <= 0) { | |
52 | ret = -1; | |
53 | goto error; | |
54 | } | |
55 | ||
56 | if (msg.size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
57 | ret = -1; | |
58 | goto error; | |
59 | } | |
60 | ||
61 | /* Add message header at buffer's start. */ | |
62 | ret = lttng_dynamic_buffer_append(&channel->reception_buffer, &msg, | |
63 | sizeof(msg)); | |
64 | if (ret) { | |
65 | goto error; | |
66 | } | |
67 | ||
68 | /* Reserve space for the payload. */ | |
69 | ret = lttng_dynamic_buffer_set_size(&channel->reception_buffer, | |
70 | channel->reception_buffer.size + msg.size); | |
71 | if (ret) { | |
72 | goto error; | |
73 | } | |
74 | ||
75 | /* Receive message payload. */ | |
76 | ret = lttcomm_recv_unix_sock(channel->socket, | |
77 | channel->reception_buffer.data + sizeof(msg), msg.size); | |
78 | if (ret < (ssize_t) msg.size) { | |
79 | ret = -1; | |
80 | goto error; | |
81 | } | |
82 | ret = 0; | |
83 | end: | |
84 | return ret; | |
85 | error: | |
e4f3498e JG |
86 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
87 | ret = -1; | |
88 | } | |
a58c490f JG |
89 | goto end; |
90 | } | |
91 | ||
92 | static | |
93 | enum lttng_notification_channel_message_type get_current_message_type( | |
94 | struct lttng_notification_channel *channel) | |
95 | { | |
96 | struct lttng_notification_channel_message *msg; | |
97 | ||
98 | assert(channel->reception_buffer.size >= sizeof(*msg)); | |
99 | ||
100 | msg = (struct lttng_notification_channel_message *) | |
101 | channel->reception_buffer.data; | |
102 | return (enum lttng_notification_channel_message_type) msg->type; | |
103 | } | |
104 | ||
105 | static | |
106 | struct lttng_notification *create_notification_from_current_message( | |
107 | struct lttng_notification_channel *channel) | |
108 | { | |
109 | ssize_t ret; | |
110 | struct lttng_notification *notification = NULL; | |
111 | struct lttng_buffer_view view; | |
112 | ||
113 | if (channel->reception_buffer.size <= | |
114 | sizeof(struct lttng_notification_channel_message)) { | |
115 | goto end; | |
116 | } | |
117 | ||
118 | view = lttng_buffer_view_from_dynamic_buffer(&channel->reception_buffer, | |
119 | sizeof(struct lttng_notification_channel_message), -1); | |
120 | ||
121 | ret = lttng_notification_create_from_buffer(&view, ¬ification); | |
122 | if (ret != channel->reception_buffer.size - | |
123 | sizeof(struct lttng_notification_channel_message)) { | |
124 | lttng_notification_destroy(notification); | |
125 | notification = NULL; | |
126 | goto end; | |
127 | } | |
128 | end: | |
129 | return notification; | |
130 | } | |
131 | ||
132 | struct lttng_notification_channel *lttng_notification_channel_create( | |
133 | struct lttng_endpoint *endpoint) | |
134 | { | |
135 | int fd, ret; | |
136 | bool is_in_tracing_group = false, is_root = false; | |
137 | char *sock_path = NULL; | |
138 | struct lttng_notification_channel *channel = NULL; | |
139 | ||
140 | if (!endpoint || | |
141 | endpoint != lttng_session_daemon_notification_endpoint) { | |
142 | goto end; | |
143 | } | |
144 | ||
145 | sock_path = zmalloc(LTTNG_PATH_MAX); | |
146 | if (!sock_path) { | |
147 | goto end; | |
148 | } | |
149 | ||
150 | channel = zmalloc(sizeof(struct lttng_notification_channel)); | |
151 | if (!channel) { | |
152 | goto end; | |
153 | } | |
154 | channel->socket = -1; | |
155 | pthread_mutex_init(&channel->lock, NULL); | |
156 | lttng_dynamic_buffer_init(&channel->reception_buffer); | |
157 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); | |
158 | ||
159 | is_root = (getuid() == 0); | |
160 | if (!is_root) { | |
161 | is_in_tracing_group = lttng_check_tracing_group(); | |
162 | } | |
163 | ||
164 | if (is_root || is_in_tracing_group) { | |
165 | lttng_ctl_copy_string(sock_path, | |
166 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
167 | LTTNG_PATH_MAX); | |
168 | ret = lttcomm_connect_unix_sock(sock_path); | |
169 | if (ret >= 0) { | |
170 | fd = ret; | |
171 | goto set_fd; | |
172 | } | |
173 | } | |
174 | ||
175 | /* Fallback to local session daemon. */ | |
176 | ret = snprintf(sock_path, LTTNG_PATH_MAX, | |
177 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
178 | utils_get_home_dir()); | |
179 | if (ret < 0 || ret >= LTTNG_PATH_MAX) { | |
180 | goto error; | |
181 | } | |
182 | ||
183 | ret = lttcomm_connect_unix_sock(sock_path); | |
184 | if (ret < 0) { | |
185 | goto error; | |
186 | } | |
187 | fd = ret; | |
188 | ||
189 | set_fd: | |
190 | channel->socket = fd; | |
191 | ||
192 | ret = handshake(channel); | |
193 | if (ret) { | |
194 | goto error; | |
195 | } | |
196 | end: | |
197 | free(sock_path); | |
198 | return channel; | |
199 | error: | |
200 | lttng_notification_channel_destroy(channel); | |
201 | channel = NULL; | |
202 | goto end; | |
203 | } | |
204 | ||
205 | enum lttng_notification_channel_status | |
206 | lttng_notification_channel_get_next_notification( | |
207 | struct lttng_notification_channel *channel, | |
208 | struct lttng_notification **_notification) | |
209 | { | |
210 | int ret; | |
211 | struct lttng_notification *notification = NULL; | |
212 | enum lttng_notification_channel_status status = | |
213 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
71e04de6 | 214 | fd_set read_fds; |
a58c490f JG |
215 | |
216 | if (!channel || !_notification) { | |
217 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
218 | goto end; | |
219 | } | |
220 | ||
94a61469 JG |
221 | pthread_mutex_lock(&channel->lock); |
222 | ||
a58c490f JG |
223 | if (channel->pending_notifications.count) { |
224 | struct pending_notification *pending_notification; | |
225 | ||
226 | assert(!cds_list_empty(&channel->pending_notifications.list)); | |
227 | ||
228 | /* Deliver one of the pending notifications. */ | |
229 | pending_notification = cds_list_first_entry( | |
230 | &channel->pending_notifications.list, | |
231 | struct pending_notification, | |
232 | node); | |
233 | notification = pending_notification->notification; | |
234 | if (!notification) { | |
235 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
236 | } | |
237 | cds_list_del(&pending_notification->node); | |
238 | channel->pending_notifications.count--; | |
239 | free(pending_notification); | |
94a61469 | 240 | goto end_unlock; |
71e04de6 JG |
241 | } |
242 | ||
243 | /* | |
244 | * Block on select() instead of the message reception itself as the | |
245 | * recvmsg() wrappers always restard on EINTR. We choose to wait | |
246 | * using select() in order to: | |
247 | * 1) Return if a signal occurs, | |
248 | * 2) Not deal with partially received messages. | |
249 | * | |
250 | * The drawback to this approach is that we assume that messages | |
251 | * are complete/well formed. If a message is shorter than its | |
252 | * announced length, receive_message() will block on recvmsg() | |
253 | * and never return (even if a signal is received). | |
254 | */ | |
255 | FD_ZERO(&read_fds); | |
256 | FD_SET(channel->socket, &read_fds); | |
257 | ret = select(channel->socket + 1, &read_fds, NULL, NULL, NULL); | |
258 | if (ret == -1) { | |
259 | status = errno == EINTR ? | |
260 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : | |
261 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
262 | goto end_unlock; | |
a58c490f JG |
263 | } |
264 | ||
a58c490f JG |
265 | ret = receive_message(channel); |
266 | if (ret) { | |
267 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
268 | goto end_unlock; | |
269 | } | |
270 | ||
271 | switch (get_current_message_type(channel)) { | |
272 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
273 | notification = create_notification_from_current_message( | |
274 | channel); | |
275 | if (!notification) { | |
276 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
277 | goto end_unlock; | |
278 | } | |
279 | break; | |
280 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
281 | /* No payload to consume. */ | |
282 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
283 | break; | |
284 | default: | |
285 | /* Protocol error. */ | |
286 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
287 | goto end_unlock; | |
288 | } | |
289 | ||
290 | end_unlock: | |
291 | pthread_mutex_unlock(&channel->lock); | |
292 | end: | |
293 | if (_notification) { | |
294 | *_notification = notification; | |
295 | } | |
296 | return status; | |
297 | } | |
298 | ||
299 | static | |
300 | int enqueue_dropped_notification( | |
301 | struct lttng_notification_channel *channel) | |
302 | { | |
303 | int ret = 0; | |
304 | struct pending_notification *pending_notification; | |
305 | struct cds_list_head *last_element = | |
306 | channel->pending_notifications.list.prev; | |
307 | ||
308 | pending_notification = caa_container_of(last_element, | |
309 | struct pending_notification, node); | |
310 | if (!pending_notification->notification) { | |
311 | /* | |
312 | * The last enqueued notification indicates dropped | |
313 | * notifications; there is nothing to do as we group | |
314 | * dropped notifications together. | |
315 | */ | |
316 | goto end; | |
317 | } | |
318 | ||
319 | if (channel->pending_notifications.count >= | |
320 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
321 | pending_notification->notification) { | |
322 | /* | |
323 | * Discard the last enqueued notification to indicate | |
324 | * that notifications were dropped at this point. | |
325 | */ | |
326 | lttng_notification_destroy( | |
327 | pending_notification->notification); | |
328 | pending_notification->notification = NULL; | |
329 | goto end; | |
330 | } | |
331 | ||
332 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
333 | if (!pending_notification) { | |
334 | ret = -1; | |
335 | goto end; | |
336 | } | |
337 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
338 | cds_list_add(&pending_notification->node, | |
339 | &channel->pending_notifications.list); | |
340 | channel->pending_notifications.count++; | |
341 | end: | |
342 | return ret; | |
343 | } | |
344 | ||
345 | static | |
346 | int enqueue_notification_from_current_message( | |
347 | struct lttng_notification_channel *channel) | |
348 | { | |
349 | int ret = 0; | |
350 | struct lttng_notification *notification; | |
351 | struct pending_notification *pending_notification; | |
352 | ||
353 | if (channel->pending_notifications.count >= | |
354 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
355 | /* Drop the notification. */ | |
356 | ret = enqueue_dropped_notification(channel); | |
357 | goto end; | |
358 | } | |
359 | ||
360 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
361 | if (!pending_notification) { | |
362 | ret = -1; | |
363 | goto error; | |
364 | } | |
365 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
366 | ||
367 | notification = create_notification_from_current_message(channel); | |
368 | if (!notification) { | |
369 | ret = -1; | |
370 | goto error; | |
371 | } | |
372 | ||
373 | pending_notification->notification = notification; | |
374 | cds_list_add(&pending_notification->node, | |
375 | &channel->pending_notifications.list); | |
376 | channel->pending_notifications.count++; | |
377 | end: | |
378 | return ret; | |
379 | error: | |
380 | free(pending_notification); | |
381 | goto end; | |
382 | } | |
383 | ||
1d757b1c JG |
384 | enum lttng_notification_channel_status |
385 | lttng_notification_channel_has_pending_notification( | |
386 | struct lttng_notification_channel *channel, | |
387 | bool *_notification_pending) | |
388 | { | |
389 | int ret; | |
390 | enum lttng_notification_channel_status status = | |
391 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
392 | fd_set read_fds; | |
393 | struct timeval timeout; | |
394 | ||
395 | FD_ZERO(&read_fds); | |
396 | memset(&timeout, 0, sizeof(timeout)); | |
397 | ||
398 | if (!channel || !_notification_pending) { | |
399 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
400 | goto end; | |
401 | } | |
402 | ||
403 | pthread_mutex_lock(&channel->lock); | |
404 | ||
405 | if (channel->pending_notifications.count) { | |
406 | *_notification_pending = true; | |
407 | goto end_unlock; | |
408 | } | |
409 | ||
410 | if (channel->socket < 0) { | |
411 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
412 | goto end_unlock; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Check, without blocking, if data is available on the channel's | |
417 | * socket. If there is data available, it is safe to read (blocking) | |
418 | * on the socket for a message from the session daemon. | |
419 | * | |
420 | * Since all commands wait for the session daemon's reply before | |
421 | * releasing the channel's lock, the protocol only allows for | |
422 | * notifications and "notification dropped" messages to come | |
423 | * through. If we receive a different message type, it is | |
424 | * considered a protocol error. | |
425 | * | |
426 | * Note that this function is not guaranteed not to block. This | |
427 | * will block until our peer (the session daemon) has sent a complete | |
428 | * message if we see data available on the socket. If the peer does | |
429 | * not respect the protocol, this may block indefinitely. | |
430 | */ | |
431 | FD_SET(channel->socket, &read_fds); | |
432 | do { | |
433 | ret = select(channel->socket + 1, &read_fds, NULL, NULL, &timeout); | |
434 | } while (ret < 0 && errno == EINTR); | |
435 | ||
436 | if (ret == 0) { | |
437 | /* No data available. */ | |
438 | *_notification_pending = false; | |
439 | goto end_unlock; | |
440 | } else if (ret < 0) { | |
441 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
442 | goto end_unlock; | |
443 | } | |
444 | ||
445 | /* Data available on socket. */ | |
446 | ret = receive_message(channel); | |
447 | if (ret) { | |
448 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
449 | goto end_unlock; | |
450 | } | |
451 | ||
452 | switch (get_current_message_type(channel)) { | |
453 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
454 | ret = enqueue_notification_from_current_message(channel); | |
455 | if (ret) { | |
0ba0fed6 | 456 | goto end_unlock; |
1d757b1c JG |
457 | } |
458 | *_notification_pending = true; | |
459 | break; | |
460 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
461 | ret = enqueue_dropped_notification(channel); | |
462 | if (ret) { | |
0ba0fed6 | 463 | goto end_unlock; |
1d757b1c JG |
464 | } |
465 | *_notification_pending = true; | |
466 | break; | |
467 | default: | |
468 | /* Protocol error. */ | |
469 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
470 | goto end_unlock; | |
471 | } | |
472 | ||
473 | end_unlock: | |
474 | pthread_mutex_unlock(&channel->lock); | |
475 | end: | |
476 | return status; | |
477 | } | |
478 | ||
a58c490f JG |
479 | static |
480 | int receive_command_reply(struct lttng_notification_channel *channel, | |
481 | enum lttng_notification_channel_status *status) | |
482 | { | |
483 | int ret; | |
484 | struct lttng_notification_channel_command_reply *reply; | |
485 | ||
486 | while (true) { | |
487 | enum lttng_notification_channel_message_type msg_type; | |
488 | ||
489 | ret = receive_message(channel); | |
490 | if (ret) { | |
491 | goto end; | |
492 | } | |
493 | ||
494 | msg_type = get_current_message_type(channel); | |
495 | switch (msg_type) { | |
496 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
497 | goto exit_loop; | |
498 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
499 | ret = enqueue_notification_from_current_message( | |
500 | channel); | |
501 | if (ret) { | |
502 | goto end; | |
503 | } | |
504 | break; | |
505 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
506 | ret = enqueue_dropped_notification(channel); | |
507 | if (ret) { | |
508 | goto end; | |
509 | } | |
510 | break; | |
511 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
512 | { | |
513 | struct lttng_notification_channel_command_handshake *handshake; | |
514 | ||
515 | handshake = (struct lttng_notification_channel_command_handshake *) | |
516 | (channel->reception_buffer.data + | |
517 | sizeof(struct lttng_notification_channel_message)); | |
518 | channel->version.major = handshake->major; | |
519 | channel->version.minor = handshake->minor; | |
520 | channel->version.set = true; | |
521 | break; | |
522 | } | |
523 | default: | |
524 | ret = -1; | |
525 | goto end; | |
526 | } | |
527 | } | |
528 | ||
529 | exit_loop: | |
530 | if (channel->reception_buffer.size < | |
531 | (sizeof(struct lttng_notification_channel_message) + | |
532 | sizeof(*reply))) { | |
533 | /* Invalid message received. */ | |
534 | ret = -1; | |
535 | goto end; | |
536 | } | |
537 | ||
538 | reply = (struct lttng_notification_channel_command_reply *) | |
539 | (channel->reception_buffer.data + | |
540 | sizeof(struct lttng_notification_channel_message)); | |
541 | *status = (enum lttng_notification_channel_status) reply->status; | |
542 | end: | |
543 | return ret; | |
544 | } | |
545 | ||
546 | static | |
547 | int handshake(struct lttng_notification_channel *channel) | |
548 | { | |
549 | ssize_t ret; | |
550 | enum lttng_notification_channel_status status = | |
551 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
552 | struct lttng_notification_channel_command_handshake handshake = { | |
553 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
554 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
555 | }; | |
556 | struct lttng_notification_channel_message msg_header = { | |
557 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
558 | .size = sizeof(handshake), | |
559 | }; | |
560 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
561 | ||
562 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
563 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
564 | ||
565 | pthread_mutex_lock(&channel->lock); | |
566 | ||
01ea340e | 567 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
568 | sizeof(send_buffer)); |
569 | if (ret < 0) { | |
570 | goto end_unlock; | |
571 | } | |
572 | ||
573 | /* Receive handshake info from the sessiond. */ | |
574 | ret = receive_command_reply(channel, &status); | |
575 | if (ret < 0) { | |
576 | goto end_unlock; | |
577 | } | |
578 | ||
579 | if (!channel->version.set) { | |
580 | ret = -1; | |
581 | goto end_unlock; | |
582 | } | |
583 | ||
584 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
585 | ret = -1; | |
586 | goto end_unlock; | |
587 | } | |
588 | ||
589 | end_unlock: | |
590 | pthread_mutex_unlock(&channel->lock); | |
591 | return ret; | |
592 | } | |
593 | ||
594 | static | |
595 | enum lttng_notification_channel_status send_condition_command( | |
596 | struct lttng_notification_channel *channel, | |
597 | enum lttng_notification_channel_message_type type, | |
598 | const struct lttng_condition *condition) | |
599 | { | |
600 | int socket; | |
3647288f | 601 | ssize_t ret; |
a58c490f JG |
602 | enum lttng_notification_channel_status status = |
603 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
3647288f JG |
604 | struct lttng_dynamic_buffer buffer; |
605 | struct lttng_notification_channel_message cmd_header = { | |
606 | .type = (int8_t) type, | |
a58c490f JG |
607 | }; |
608 | ||
3647288f JG |
609 | lttng_dynamic_buffer_init(&buffer); |
610 | ||
a58c490f JG |
611 | if (!channel) { |
612 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
613 | goto end; | |
614 | } | |
615 | ||
616 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
617 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
618 | ||
619 | pthread_mutex_lock(&channel->lock); | |
620 | socket = channel->socket; | |
621 | if (!lttng_condition_validate(condition)) { | |
622 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
623 | goto end_unlock; | |
624 | } | |
625 | ||
3647288f JG |
626 | ret = lttng_dynamic_buffer_append(&buffer, &cmd_header, |
627 | sizeof(cmd_header)); | |
628 | if (ret) { | |
629 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
630 | goto end_unlock; |
631 | } | |
632 | ||
3647288f JG |
633 | ret = lttng_condition_serialize(condition, &buffer); |
634 | if (ret) { | |
635 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
636 | goto end_unlock; |
637 | } | |
638 | ||
3647288f JG |
639 | /* Update payload length. */ |
640 | ((struct lttng_notification_channel_message *) buffer.data)->size = | |
641 | (uint32_t) (buffer.size - sizeof(cmd_header)); | |
642 | ||
643 | ret = lttcomm_send_unix_sock(socket, buffer.data, buffer.size); | |
a58c490f JG |
644 | if (ret < 0) { |
645 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
646 | goto end_unlock; | |
647 | } | |
648 | ||
649 | ret = receive_command_reply(channel, &status); | |
650 | if (ret < 0) { | |
651 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
652 | goto end_unlock; | |
653 | } | |
654 | end_unlock: | |
655 | pthread_mutex_unlock(&channel->lock); | |
656 | end: | |
3647288f | 657 | lttng_dynamic_buffer_reset(&buffer); |
a58c490f JG |
658 | return status; |
659 | } | |
660 | ||
661 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
662 | struct lttng_notification_channel *channel, | |
663 | const struct lttng_condition *condition) | |
664 | { | |
665 | return send_condition_command(channel, | |
666 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
667 | condition); | |
668 | } | |
669 | ||
670 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
671 | struct lttng_notification_channel *channel, | |
672 | const struct lttng_condition *condition) | |
673 | { | |
674 | return send_condition_command(channel, | |
675 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
676 | condition); | |
677 | } | |
678 | ||
679 | void lttng_notification_channel_destroy( | |
680 | struct lttng_notification_channel *channel) | |
681 | { | |
682 | if (!channel) { | |
683 | return; | |
684 | } | |
685 | ||
686 | if (channel->socket >= 0) { | |
687 | (void) lttcomm_close_unix_sock(channel->socket); | |
688 | } | |
689 | pthread_mutex_destroy(&channel->lock); | |
690 | lttng_dynamic_buffer_reset(&channel->reception_buffer); | |
691 | free(channel); | |
692 | } |