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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; | |
f83bcd90 | 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; |
f83bcd90 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); | |
a57a7f22 | 292 | *_notification = notification; |
a58c490f | 293 | end: |
a58c490f JG |
294 | return status; |
295 | } | |
296 | ||
297 | static | |
298 | int enqueue_dropped_notification( | |
299 | struct lttng_notification_channel *channel) | |
300 | { | |
301 | int ret = 0; | |
302 | struct pending_notification *pending_notification; | |
303 | struct cds_list_head *last_element = | |
304 | channel->pending_notifications.list.prev; | |
305 | ||
306 | pending_notification = caa_container_of(last_element, | |
307 | struct pending_notification, node); | |
308 | if (!pending_notification->notification) { | |
309 | /* | |
310 | * The last enqueued notification indicates dropped | |
311 | * notifications; there is nothing to do as we group | |
312 | * dropped notifications together. | |
313 | */ | |
314 | goto end; | |
315 | } | |
316 | ||
317 | if (channel->pending_notifications.count >= | |
318 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
319 | pending_notification->notification) { | |
320 | /* | |
321 | * Discard the last enqueued notification to indicate | |
322 | * that notifications were dropped at this point. | |
323 | */ | |
324 | lttng_notification_destroy( | |
325 | pending_notification->notification); | |
326 | pending_notification->notification = NULL; | |
327 | goto end; | |
328 | } | |
329 | ||
330 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
331 | if (!pending_notification) { | |
332 | ret = -1; | |
333 | goto end; | |
334 | } | |
335 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
336 | cds_list_add(&pending_notification->node, | |
337 | &channel->pending_notifications.list); | |
338 | channel->pending_notifications.count++; | |
339 | end: | |
340 | return ret; | |
341 | } | |
342 | ||
343 | static | |
344 | int enqueue_notification_from_current_message( | |
345 | struct lttng_notification_channel *channel) | |
346 | { | |
347 | int ret = 0; | |
348 | struct lttng_notification *notification; | |
349 | struct pending_notification *pending_notification; | |
350 | ||
351 | if (channel->pending_notifications.count >= | |
352 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
353 | /* Drop the notification. */ | |
354 | ret = enqueue_dropped_notification(channel); | |
355 | goto end; | |
356 | } | |
357 | ||
358 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
359 | if (!pending_notification) { | |
360 | ret = -1; | |
361 | goto error; | |
362 | } | |
363 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
364 | ||
365 | notification = create_notification_from_current_message(channel); | |
366 | if (!notification) { | |
367 | ret = -1; | |
368 | goto error; | |
369 | } | |
370 | ||
371 | pending_notification->notification = notification; | |
372 | cds_list_add(&pending_notification->node, | |
373 | &channel->pending_notifications.list); | |
374 | channel->pending_notifications.count++; | |
375 | end: | |
376 | return ret; | |
377 | error: | |
378 | free(pending_notification); | |
379 | goto end; | |
380 | } | |
381 | ||
1d757b1c JG |
382 | enum lttng_notification_channel_status |
383 | lttng_notification_channel_has_pending_notification( | |
384 | struct lttng_notification_channel *channel, | |
385 | bool *_notification_pending) | |
386 | { | |
387 | int ret; | |
388 | enum lttng_notification_channel_status status = | |
389 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
390 | fd_set read_fds; | |
391 | struct timeval timeout; | |
392 | ||
393 | FD_ZERO(&read_fds); | |
394 | memset(&timeout, 0, sizeof(timeout)); | |
395 | ||
396 | if (!channel || !_notification_pending) { | |
397 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
398 | goto end; | |
399 | } | |
400 | ||
401 | pthread_mutex_lock(&channel->lock); | |
402 | ||
403 | if (channel->pending_notifications.count) { | |
404 | *_notification_pending = true; | |
405 | goto end_unlock; | |
406 | } | |
407 | ||
408 | if (channel->socket < 0) { | |
409 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
410 | goto end_unlock; | |
411 | } | |
412 | ||
413 | /* | |
414 | * Check, without blocking, if data is available on the channel's | |
415 | * socket. If there is data available, it is safe to read (blocking) | |
416 | * on the socket for a message from the session daemon. | |
417 | * | |
418 | * Since all commands wait for the session daemon's reply before | |
419 | * releasing the channel's lock, the protocol only allows for | |
420 | * notifications and "notification dropped" messages to come | |
421 | * through. If we receive a different message type, it is | |
422 | * considered a protocol error. | |
423 | * | |
424 | * Note that this function is not guaranteed not to block. This | |
425 | * will block until our peer (the session daemon) has sent a complete | |
426 | * message if we see data available on the socket. If the peer does | |
427 | * not respect the protocol, this may block indefinitely. | |
428 | */ | |
429 | FD_SET(channel->socket, &read_fds); | |
430 | do { | |
431 | ret = select(channel->socket + 1, &read_fds, NULL, NULL, &timeout); | |
432 | } while (ret < 0 && errno == EINTR); | |
433 | ||
434 | if (ret == 0) { | |
435 | /* No data available. */ | |
436 | *_notification_pending = false; | |
437 | goto end_unlock; | |
438 | } else if (ret < 0) { | |
439 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
440 | goto end_unlock; | |
441 | } | |
442 | ||
443 | /* Data available on socket. */ | |
444 | ret = receive_message(channel); | |
445 | if (ret) { | |
446 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
447 | goto end_unlock; | |
448 | } | |
449 | ||
450 | switch (get_current_message_type(channel)) { | |
451 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
452 | ret = enqueue_notification_from_current_message(channel); | |
453 | if (ret) { | |
0ba0fed6 | 454 | goto end_unlock; |
1d757b1c JG |
455 | } |
456 | *_notification_pending = true; | |
457 | break; | |
458 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
459 | ret = enqueue_dropped_notification(channel); | |
460 | if (ret) { | |
0ba0fed6 | 461 | goto end_unlock; |
1d757b1c JG |
462 | } |
463 | *_notification_pending = true; | |
464 | break; | |
465 | default: | |
466 | /* Protocol error. */ | |
467 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
468 | goto end_unlock; | |
469 | } | |
470 | ||
471 | end_unlock: | |
472 | pthread_mutex_unlock(&channel->lock); | |
473 | end: | |
474 | return status; | |
475 | } | |
476 | ||
a58c490f JG |
477 | static |
478 | int receive_command_reply(struct lttng_notification_channel *channel, | |
479 | enum lttng_notification_channel_status *status) | |
480 | { | |
481 | int ret; | |
482 | struct lttng_notification_channel_command_reply *reply; | |
483 | ||
484 | while (true) { | |
485 | enum lttng_notification_channel_message_type msg_type; | |
486 | ||
487 | ret = receive_message(channel); | |
488 | if (ret) { | |
489 | goto end; | |
490 | } | |
491 | ||
492 | msg_type = get_current_message_type(channel); | |
493 | switch (msg_type) { | |
494 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
495 | goto exit_loop; | |
496 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
497 | ret = enqueue_notification_from_current_message( | |
498 | channel); | |
499 | if (ret) { | |
500 | goto end; | |
501 | } | |
502 | break; | |
503 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
504 | ret = enqueue_dropped_notification(channel); | |
505 | if (ret) { | |
506 | goto end; | |
507 | } | |
508 | break; | |
509 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
510 | { | |
511 | struct lttng_notification_channel_command_handshake *handshake; | |
512 | ||
513 | handshake = (struct lttng_notification_channel_command_handshake *) | |
514 | (channel->reception_buffer.data + | |
515 | sizeof(struct lttng_notification_channel_message)); | |
516 | channel->version.major = handshake->major; | |
517 | channel->version.minor = handshake->minor; | |
518 | channel->version.set = true; | |
519 | break; | |
520 | } | |
521 | default: | |
522 | ret = -1; | |
523 | goto end; | |
524 | } | |
525 | } | |
526 | ||
527 | exit_loop: | |
528 | if (channel->reception_buffer.size < | |
529 | (sizeof(struct lttng_notification_channel_message) + | |
530 | sizeof(*reply))) { | |
531 | /* Invalid message received. */ | |
532 | ret = -1; | |
533 | goto end; | |
534 | } | |
535 | ||
536 | reply = (struct lttng_notification_channel_command_reply *) | |
537 | (channel->reception_buffer.data + | |
538 | sizeof(struct lttng_notification_channel_message)); | |
539 | *status = (enum lttng_notification_channel_status) reply->status; | |
540 | end: | |
541 | return ret; | |
542 | } | |
543 | ||
544 | static | |
545 | int handshake(struct lttng_notification_channel *channel) | |
546 | { | |
547 | ssize_t ret; | |
548 | enum lttng_notification_channel_status status = | |
549 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
550 | struct lttng_notification_channel_command_handshake handshake = { | |
551 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
552 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
553 | }; | |
554 | struct lttng_notification_channel_message msg_header = { | |
555 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
556 | .size = sizeof(handshake), | |
557 | }; | |
558 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
559 | ||
560 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
561 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
562 | ||
563 | pthread_mutex_lock(&channel->lock); | |
564 | ||
01ea340e | 565 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
566 | sizeof(send_buffer)); |
567 | if (ret < 0) { | |
568 | goto end_unlock; | |
569 | } | |
570 | ||
571 | /* Receive handshake info from the sessiond. */ | |
572 | ret = receive_command_reply(channel, &status); | |
573 | if (ret < 0) { | |
574 | goto end_unlock; | |
575 | } | |
576 | ||
577 | if (!channel->version.set) { | |
578 | ret = -1; | |
579 | goto end_unlock; | |
580 | } | |
581 | ||
582 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
583 | ret = -1; | |
584 | goto end_unlock; | |
585 | } | |
586 | ||
587 | end_unlock: | |
588 | pthread_mutex_unlock(&channel->lock); | |
589 | return ret; | |
590 | } | |
591 | ||
592 | static | |
593 | enum lttng_notification_channel_status send_condition_command( | |
594 | struct lttng_notification_channel *channel, | |
595 | enum lttng_notification_channel_message_type type, | |
596 | const struct lttng_condition *condition) | |
597 | { | |
598 | int socket; | |
3647288f | 599 | ssize_t ret; |
a58c490f JG |
600 | enum lttng_notification_channel_status status = |
601 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
3647288f JG |
602 | struct lttng_dynamic_buffer buffer; |
603 | struct lttng_notification_channel_message cmd_header = { | |
604 | .type = (int8_t) type, | |
a58c490f JG |
605 | }; |
606 | ||
3647288f JG |
607 | lttng_dynamic_buffer_init(&buffer); |
608 | ||
a58c490f JG |
609 | if (!channel) { |
610 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
611 | goto end; | |
612 | } | |
613 | ||
614 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
615 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
616 | ||
617 | pthread_mutex_lock(&channel->lock); | |
618 | socket = channel->socket; | |
619 | if (!lttng_condition_validate(condition)) { | |
620 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
621 | goto end_unlock; | |
622 | } | |
623 | ||
3647288f JG |
624 | ret = lttng_dynamic_buffer_append(&buffer, &cmd_header, |
625 | sizeof(cmd_header)); | |
626 | if (ret) { | |
627 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
628 | goto end_unlock; |
629 | } | |
630 | ||
3647288f JG |
631 | ret = lttng_condition_serialize(condition, &buffer); |
632 | if (ret) { | |
633 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
634 | goto end_unlock; |
635 | } | |
636 | ||
3647288f JG |
637 | /* Update payload length. */ |
638 | ((struct lttng_notification_channel_message *) buffer.data)->size = | |
639 | (uint32_t) (buffer.size - sizeof(cmd_header)); | |
640 | ||
641 | ret = lttcomm_send_unix_sock(socket, buffer.data, buffer.size); | |
a58c490f JG |
642 | if (ret < 0) { |
643 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
644 | goto end_unlock; | |
645 | } | |
646 | ||
647 | ret = receive_command_reply(channel, &status); | |
648 | if (ret < 0) { | |
649 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
650 | goto end_unlock; | |
651 | } | |
652 | end_unlock: | |
653 | pthread_mutex_unlock(&channel->lock); | |
654 | end: | |
3647288f | 655 | lttng_dynamic_buffer_reset(&buffer); |
a58c490f JG |
656 | return status; |
657 | } | |
658 | ||
659 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
660 | struct lttng_notification_channel *channel, | |
661 | const struct lttng_condition *condition) | |
662 | { | |
663 | return send_condition_command(channel, | |
664 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
665 | condition); | |
666 | } | |
667 | ||
668 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
669 | struct lttng_notification_channel *channel, | |
670 | const struct lttng_condition *condition) | |
671 | { | |
672 | return send_condition_command(channel, | |
673 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
674 | condition); | |
675 | } | |
676 | ||
677 | void lttng_notification_channel_destroy( | |
678 | struct lttng_notification_channel *channel) | |
679 | { | |
680 | if (!channel) { | |
681 | return; | |
682 | } | |
683 | ||
684 | if (channel->socket >= 0) { | |
685 | (void) lttcomm_close_unix_sock(channel->socket); | |
686 | } | |
687 | pthread_mutex_destroy(&channel->lock); | |
688 | lttng_dynamic_buffer_reset(&channel->reception_buffer); | |
689 | free(channel); | |
690 | } |