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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" | |
06c75827 | 29 | #include <common/compat/poll.h> |
a58c490f JG |
30 | |
31 | static | |
32 | int handshake(struct lttng_notification_channel *channel); | |
33 | ||
34 | /* | |
35 | * Populates the reception buffer with the next complete message. | |
1d757b1c | 36 | * The caller must acquire the channel's lock. |
a58c490f JG |
37 | */ |
38 | static | |
39 | int receive_message(struct lttng_notification_channel *channel) | |
40 | { | |
41 | ssize_t ret; | |
42 | struct lttng_notification_channel_message msg; | |
43 | ||
1d757b1c JG |
44 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
45 | ret = -1; | |
46 | goto end; | |
a58c490f JG |
47 | } |
48 | ||
49 | ret = lttcomm_recv_unix_sock(channel->socket, &msg, sizeof(msg)); | |
50 | if (ret <= 0) { | |
51 | ret = -1; | |
52 | goto error; | |
53 | } | |
54 | ||
55 | if (msg.size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
56 | ret = -1; | |
57 | goto error; | |
58 | } | |
59 | ||
60 | /* Add message header at buffer's start. */ | |
61 | ret = lttng_dynamic_buffer_append(&channel->reception_buffer, &msg, | |
62 | sizeof(msg)); | |
63 | if (ret) { | |
64 | goto error; | |
65 | } | |
66 | ||
67 | /* Reserve space for the payload. */ | |
68 | ret = lttng_dynamic_buffer_set_size(&channel->reception_buffer, | |
69 | channel->reception_buffer.size + msg.size); | |
70 | if (ret) { | |
71 | goto error; | |
72 | } | |
73 | ||
74 | /* Receive message payload. */ | |
75 | ret = lttcomm_recv_unix_sock(channel->socket, | |
76 | channel->reception_buffer.data + sizeof(msg), msg.size); | |
77 | if (ret < (ssize_t) msg.size) { | |
78 | ret = -1; | |
79 | goto error; | |
80 | } | |
81 | ret = 0; | |
82 | end: | |
83 | return ret; | |
84 | error: | |
e4f3498e JG |
85 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
86 | ret = -1; | |
87 | } | |
a58c490f JG |
88 | goto end; |
89 | } | |
90 | ||
91 | static | |
92 | enum lttng_notification_channel_message_type get_current_message_type( | |
93 | struct lttng_notification_channel *channel) | |
94 | { | |
95 | struct lttng_notification_channel_message *msg; | |
96 | ||
97 | assert(channel->reception_buffer.size >= sizeof(*msg)); | |
98 | ||
99 | msg = (struct lttng_notification_channel_message *) | |
100 | channel->reception_buffer.data; | |
101 | return (enum lttng_notification_channel_message_type) msg->type; | |
102 | } | |
103 | ||
104 | static | |
105 | struct lttng_notification *create_notification_from_current_message( | |
106 | struct lttng_notification_channel *channel) | |
107 | { | |
108 | ssize_t ret; | |
109 | struct lttng_notification *notification = NULL; | |
110 | struct lttng_buffer_view view; | |
111 | ||
112 | if (channel->reception_buffer.size <= | |
113 | sizeof(struct lttng_notification_channel_message)) { | |
114 | goto end; | |
115 | } | |
116 | ||
117 | view = lttng_buffer_view_from_dynamic_buffer(&channel->reception_buffer, | |
118 | sizeof(struct lttng_notification_channel_message), -1); | |
119 | ||
120 | ret = lttng_notification_create_from_buffer(&view, ¬ification); | |
121 | if (ret != channel->reception_buffer.size - | |
122 | sizeof(struct lttng_notification_channel_message)) { | |
123 | lttng_notification_destroy(notification); | |
124 | notification = NULL; | |
125 | goto end; | |
126 | } | |
127 | end: | |
128 | return notification; | |
129 | } | |
130 | ||
131 | struct lttng_notification_channel *lttng_notification_channel_create( | |
132 | struct lttng_endpoint *endpoint) | |
133 | { | |
134 | int fd, ret; | |
135 | bool is_in_tracing_group = false, is_root = false; | |
136 | char *sock_path = NULL; | |
137 | struct lttng_notification_channel *channel = NULL; | |
138 | ||
139 | if (!endpoint || | |
140 | endpoint != lttng_session_daemon_notification_endpoint) { | |
141 | goto end; | |
142 | } | |
143 | ||
144 | sock_path = zmalloc(LTTNG_PATH_MAX); | |
145 | if (!sock_path) { | |
146 | goto end; | |
147 | } | |
148 | ||
149 | channel = zmalloc(sizeof(struct lttng_notification_channel)); | |
150 | if (!channel) { | |
151 | goto end; | |
152 | } | |
153 | channel->socket = -1; | |
154 | pthread_mutex_init(&channel->lock, NULL); | |
155 | lttng_dynamic_buffer_init(&channel->reception_buffer); | |
156 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); | |
157 | ||
158 | is_root = (getuid() == 0); | |
159 | if (!is_root) { | |
160 | is_in_tracing_group = lttng_check_tracing_group(); | |
161 | } | |
162 | ||
163 | if (is_root || is_in_tracing_group) { | |
55fb8091 | 164 | ret = lttng_strncpy(sock_path, |
a58c490f JG |
165 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, |
166 | LTTNG_PATH_MAX); | |
55fb8091 JG |
167 | if (ret) { |
168 | ret = -LTTNG_ERR_INVALID; | |
169 | goto error; | |
170 | } | |
171 | ||
a58c490f JG |
172 | ret = lttcomm_connect_unix_sock(sock_path); |
173 | if (ret >= 0) { | |
174 | fd = ret; | |
175 | goto set_fd; | |
176 | } | |
177 | } | |
178 | ||
179 | /* Fallback to local session daemon. */ | |
180 | ret = snprintf(sock_path, LTTNG_PATH_MAX, | |
181 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
182 | utils_get_home_dir()); | |
183 | if (ret < 0 || ret >= LTTNG_PATH_MAX) { | |
184 | goto error; | |
185 | } | |
186 | ||
187 | ret = lttcomm_connect_unix_sock(sock_path); | |
188 | if (ret < 0) { | |
189 | goto error; | |
190 | } | |
191 | fd = ret; | |
192 | ||
193 | set_fd: | |
194 | channel->socket = fd; | |
195 | ||
196 | ret = handshake(channel); | |
197 | if (ret) { | |
198 | goto error; | |
199 | } | |
200 | end: | |
201 | free(sock_path); | |
202 | return channel; | |
203 | error: | |
204 | lttng_notification_channel_destroy(channel); | |
205 | channel = NULL; | |
206 | goto end; | |
207 | } | |
208 | ||
209 | enum lttng_notification_channel_status | |
210 | lttng_notification_channel_get_next_notification( | |
211 | struct lttng_notification_channel *channel, | |
212 | struct lttng_notification **_notification) | |
213 | { | |
214 | int ret; | |
215 | struct lttng_notification *notification = NULL; | |
216 | enum lttng_notification_channel_status status = | |
217 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
06c75827 | 218 | struct lttng_poll_event events; |
a58c490f JG |
219 | |
220 | if (!channel || !_notification) { | |
221 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
222 | goto end; | |
223 | } | |
224 | ||
94a61469 JG |
225 | pthread_mutex_lock(&channel->lock); |
226 | ||
a58c490f JG |
227 | if (channel->pending_notifications.count) { |
228 | struct pending_notification *pending_notification; | |
229 | ||
230 | assert(!cds_list_empty(&channel->pending_notifications.list)); | |
231 | ||
232 | /* Deliver one of the pending notifications. */ | |
233 | pending_notification = cds_list_first_entry( | |
234 | &channel->pending_notifications.list, | |
235 | struct pending_notification, | |
236 | node); | |
237 | notification = pending_notification->notification; | |
238 | if (!notification) { | |
239 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
240 | } | |
241 | cds_list_del(&pending_notification->node); | |
242 | channel->pending_notifications.count--; | |
243 | free(pending_notification); | |
94a61469 | 244 | goto end_unlock; |
71e04de6 JG |
245 | } |
246 | ||
247 | /* | |
06c75827 MD |
248 | * Block on interruptible epoll/poll() instead of the message reception |
249 | * itself as the recvmsg() wrappers always restart on EINTR. We choose | |
250 | * to wait using interruptible epoll/poll() in order to: | |
71e04de6 JG |
251 | * 1) Return if a signal occurs, |
252 | * 2) Not deal with partially received messages. | |
253 | * | |
254 | * The drawback to this approach is that we assume that messages | |
255 | * are complete/well formed. If a message is shorter than its | |
256 | * announced length, receive_message() will block on recvmsg() | |
257 | * and never return (even if a signal is received). | |
258 | */ | |
06c75827 MD |
259 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
260 | if (ret < 0) { | |
261 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
262 | goto end_unlock; | |
263 | } | |
264 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
265 | if (ret < 0) { | |
266 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
267 | goto end_clean_poll; | |
268 | } | |
269 | ret = lttng_poll_wait_interruptible(&events, -1); | |
270 | if (ret <= 0) { | |
271 | status = (ret == -1 && errno == EINTR) ? | |
71e04de6 JG |
272 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : |
273 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 274 | goto end_clean_poll; |
a58c490f JG |
275 | } |
276 | ||
a58c490f JG |
277 | ret = receive_message(channel); |
278 | if (ret) { | |
279 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 280 | goto end_clean_poll; |
a58c490f JG |
281 | } |
282 | ||
283 | switch (get_current_message_type(channel)) { | |
284 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
285 | notification = create_notification_from_current_message( | |
286 | channel); | |
287 | if (!notification) { | |
288 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 289 | goto end_clean_poll; |
a58c490f JG |
290 | } |
291 | break; | |
292 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
293 | /* No payload to consume. */ | |
294 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
295 | break; | |
296 | default: | |
297 | /* Protocol error. */ | |
298 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 299 | goto end_clean_poll; |
a58c490f JG |
300 | } |
301 | ||
06c75827 MD |
302 | end_clean_poll: |
303 | lttng_poll_clean(&events); | |
a58c490f JG |
304 | end_unlock: |
305 | pthread_mutex_unlock(&channel->lock); | |
d12522c8 | 306 | *_notification = notification; |
a58c490f | 307 | end: |
a58c490f JG |
308 | return status; |
309 | } | |
310 | ||
311 | static | |
312 | int enqueue_dropped_notification( | |
313 | struct lttng_notification_channel *channel) | |
314 | { | |
315 | int ret = 0; | |
316 | struct pending_notification *pending_notification; | |
317 | struct cds_list_head *last_element = | |
318 | channel->pending_notifications.list.prev; | |
319 | ||
320 | pending_notification = caa_container_of(last_element, | |
321 | struct pending_notification, node); | |
322 | if (!pending_notification->notification) { | |
323 | /* | |
324 | * The last enqueued notification indicates dropped | |
325 | * notifications; there is nothing to do as we group | |
326 | * dropped notifications together. | |
327 | */ | |
328 | goto end; | |
329 | } | |
330 | ||
331 | if (channel->pending_notifications.count >= | |
332 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
333 | pending_notification->notification) { | |
334 | /* | |
335 | * Discard the last enqueued notification to indicate | |
336 | * that notifications were dropped at this point. | |
337 | */ | |
338 | lttng_notification_destroy( | |
339 | pending_notification->notification); | |
340 | pending_notification->notification = NULL; | |
341 | goto end; | |
342 | } | |
343 | ||
344 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
345 | if (!pending_notification) { | |
346 | ret = -1; | |
347 | goto end; | |
348 | } | |
349 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
350 | cds_list_add(&pending_notification->node, | |
351 | &channel->pending_notifications.list); | |
352 | channel->pending_notifications.count++; | |
353 | end: | |
354 | return ret; | |
355 | } | |
356 | ||
357 | static | |
358 | int enqueue_notification_from_current_message( | |
359 | struct lttng_notification_channel *channel) | |
360 | { | |
361 | int ret = 0; | |
362 | struct lttng_notification *notification; | |
363 | struct pending_notification *pending_notification; | |
364 | ||
365 | if (channel->pending_notifications.count >= | |
366 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
367 | /* Drop the notification. */ | |
368 | ret = enqueue_dropped_notification(channel); | |
369 | goto end; | |
370 | } | |
371 | ||
372 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
373 | if (!pending_notification) { | |
374 | ret = -1; | |
375 | goto error; | |
376 | } | |
377 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
378 | ||
379 | notification = create_notification_from_current_message(channel); | |
380 | if (!notification) { | |
381 | ret = -1; | |
382 | goto error; | |
383 | } | |
384 | ||
385 | pending_notification->notification = notification; | |
386 | cds_list_add(&pending_notification->node, | |
387 | &channel->pending_notifications.list); | |
388 | channel->pending_notifications.count++; | |
389 | end: | |
390 | return ret; | |
391 | error: | |
392 | free(pending_notification); | |
393 | goto end; | |
394 | } | |
395 | ||
1d757b1c JG |
396 | enum lttng_notification_channel_status |
397 | lttng_notification_channel_has_pending_notification( | |
398 | struct lttng_notification_channel *channel, | |
399 | bool *_notification_pending) | |
400 | { | |
401 | int ret; | |
402 | enum lttng_notification_channel_status status = | |
403 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
06c75827 | 404 | struct lttng_poll_event events; |
1d757b1c JG |
405 | |
406 | if (!channel || !_notification_pending) { | |
407 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
408 | goto end; | |
409 | } | |
410 | ||
411 | pthread_mutex_lock(&channel->lock); | |
412 | ||
413 | if (channel->pending_notifications.count) { | |
414 | *_notification_pending = true; | |
415 | goto end_unlock; | |
416 | } | |
417 | ||
418 | if (channel->socket < 0) { | |
419 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
420 | goto end_unlock; | |
421 | } | |
422 | ||
423 | /* | |
424 | * Check, without blocking, if data is available on the channel's | |
425 | * socket. If there is data available, it is safe to read (blocking) | |
426 | * on the socket for a message from the session daemon. | |
427 | * | |
428 | * Since all commands wait for the session daemon's reply before | |
429 | * releasing the channel's lock, the protocol only allows for | |
430 | * notifications and "notification dropped" messages to come | |
431 | * through. If we receive a different message type, it is | |
432 | * considered a protocol error. | |
433 | * | |
434 | * Note that this function is not guaranteed not to block. This | |
435 | * will block until our peer (the session daemon) has sent a complete | |
436 | * message if we see data available on the socket. If the peer does | |
437 | * not respect the protocol, this may block indefinitely. | |
438 | */ | |
06c75827 MD |
439 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
440 | if (ret < 0) { | |
441 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
442 | goto end_unlock; | |
443 | } | |
444 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
445 | if (ret < 0) { | |
446 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
447 | goto end_clean_poll; | |
448 | } | |
449 | /* timeout = 0: return immediately. */ | |
450 | ret = lttng_poll_wait_interruptible(&events, 0); | |
1d757b1c JG |
451 | if (ret == 0) { |
452 | /* No data available. */ | |
453 | *_notification_pending = false; | |
06c75827 | 454 | goto end_clean_poll; |
1d757b1c JG |
455 | } else if (ret < 0) { |
456 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 457 | goto end_clean_poll; |
1d757b1c JG |
458 | } |
459 | ||
460 | /* Data available on socket. */ | |
461 | ret = receive_message(channel); | |
462 | if (ret) { | |
463 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 464 | goto end_clean_poll; |
1d757b1c JG |
465 | } |
466 | ||
467 | switch (get_current_message_type(channel)) { | |
468 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
469 | ret = enqueue_notification_from_current_message(channel); | |
470 | if (ret) { | |
06c75827 | 471 | goto end_clean_poll; |
1d757b1c JG |
472 | } |
473 | *_notification_pending = true; | |
474 | break; | |
475 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
476 | ret = enqueue_dropped_notification(channel); | |
477 | if (ret) { | |
06c75827 | 478 | goto end_clean_poll; |
1d757b1c JG |
479 | } |
480 | *_notification_pending = true; | |
481 | break; | |
482 | default: | |
483 | /* Protocol error. */ | |
484 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
06c75827 | 485 | goto end_clean_poll; |
1d757b1c JG |
486 | } |
487 | ||
06c75827 MD |
488 | end_clean_poll: |
489 | lttng_poll_clean(&events); | |
1d757b1c JG |
490 | end_unlock: |
491 | pthread_mutex_unlock(&channel->lock); | |
492 | end: | |
493 | return status; | |
494 | } | |
495 | ||
a58c490f JG |
496 | static |
497 | int receive_command_reply(struct lttng_notification_channel *channel, | |
498 | enum lttng_notification_channel_status *status) | |
499 | { | |
500 | int ret; | |
501 | struct lttng_notification_channel_command_reply *reply; | |
502 | ||
503 | while (true) { | |
504 | enum lttng_notification_channel_message_type msg_type; | |
505 | ||
506 | ret = receive_message(channel); | |
507 | if (ret) { | |
508 | goto end; | |
509 | } | |
510 | ||
511 | msg_type = get_current_message_type(channel); | |
512 | switch (msg_type) { | |
513 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
514 | goto exit_loop; | |
515 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
516 | ret = enqueue_notification_from_current_message( | |
517 | channel); | |
518 | if (ret) { | |
519 | goto end; | |
520 | } | |
521 | break; | |
522 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
523 | ret = enqueue_dropped_notification(channel); | |
524 | if (ret) { | |
525 | goto end; | |
526 | } | |
527 | break; | |
528 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
529 | { | |
530 | struct lttng_notification_channel_command_handshake *handshake; | |
531 | ||
532 | handshake = (struct lttng_notification_channel_command_handshake *) | |
533 | (channel->reception_buffer.data + | |
534 | sizeof(struct lttng_notification_channel_message)); | |
535 | channel->version.major = handshake->major; | |
536 | channel->version.minor = handshake->minor; | |
537 | channel->version.set = true; | |
538 | break; | |
539 | } | |
540 | default: | |
541 | ret = -1; | |
542 | goto end; | |
543 | } | |
544 | } | |
545 | ||
546 | exit_loop: | |
547 | if (channel->reception_buffer.size < | |
548 | (sizeof(struct lttng_notification_channel_message) + | |
549 | sizeof(*reply))) { | |
550 | /* Invalid message received. */ | |
551 | ret = -1; | |
552 | goto end; | |
553 | } | |
554 | ||
555 | reply = (struct lttng_notification_channel_command_reply *) | |
556 | (channel->reception_buffer.data + | |
557 | sizeof(struct lttng_notification_channel_message)); | |
558 | *status = (enum lttng_notification_channel_status) reply->status; | |
559 | end: | |
560 | return ret; | |
561 | } | |
562 | ||
563 | static | |
564 | int handshake(struct lttng_notification_channel *channel) | |
565 | { | |
566 | ssize_t ret; | |
567 | enum lttng_notification_channel_status status = | |
568 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
569 | struct lttng_notification_channel_command_handshake handshake = { | |
570 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
571 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
572 | }; | |
573 | struct lttng_notification_channel_message msg_header = { | |
574 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
575 | .size = sizeof(handshake), | |
576 | }; | |
577 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
578 | ||
579 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
580 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
581 | ||
582 | pthread_mutex_lock(&channel->lock); | |
583 | ||
01ea340e | 584 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
585 | sizeof(send_buffer)); |
586 | if (ret < 0) { | |
587 | goto end_unlock; | |
588 | } | |
589 | ||
590 | /* Receive handshake info from the sessiond. */ | |
591 | ret = receive_command_reply(channel, &status); | |
592 | if (ret < 0) { | |
593 | goto end_unlock; | |
594 | } | |
595 | ||
596 | if (!channel->version.set) { | |
597 | ret = -1; | |
598 | goto end_unlock; | |
599 | } | |
600 | ||
601 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
602 | ret = -1; | |
603 | goto end_unlock; | |
604 | } | |
605 | ||
606 | end_unlock: | |
607 | pthread_mutex_unlock(&channel->lock); | |
608 | return ret; | |
609 | } | |
610 | ||
611 | static | |
612 | enum lttng_notification_channel_status send_condition_command( | |
613 | struct lttng_notification_channel *channel, | |
614 | enum lttng_notification_channel_message_type type, | |
615 | const struct lttng_condition *condition) | |
616 | { | |
617 | int socket; | |
3647288f | 618 | ssize_t ret; |
a58c490f JG |
619 | enum lttng_notification_channel_status status = |
620 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
3647288f JG |
621 | struct lttng_dynamic_buffer buffer; |
622 | struct lttng_notification_channel_message cmd_header = { | |
623 | .type = (int8_t) type, | |
a58c490f JG |
624 | }; |
625 | ||
3647288f JG |
626 | lttng_dynamic_buffer_init(&buffer); |
627 | ||
a58c490f JG |
628 | if (!channel) { |
629 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
630 | goto end; | |
631 | } | |
632 | ||
633 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
634 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
635 | ||
636 | pthread_mutex_lock(&channel->lock); | |
637 | socket = channel->socket; | |
638 | if (!lttng_condition_validate(condition)) { | |
639 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
640 | goto end_unlock; | |
641 | } | |
642 | ||
3647288f JG |
643 | ret = lttng_dynamic_buffer_append(&buffer, &cmd_header, |
644 | sizeof(cmd_header)); | |
645 | if (ret) { | |
646 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
647 | goto end_unlock; |
648 | } | |
649 | ||
3647288f JG |
650 | ret = lttng_condition_serialize(condition, &buffer); |
651 | if (ret) { | |
652 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
653 | goto end_unlock; |
654 | } | |
655 | ||
3647288f JG |
656 | /* Update payload length. */ |
657 | ((struct lttng_notification_channel_message *) buffer.data)->size = | |
658 | (uint32_t) (buffer.size - sizeof(cmd_header)); | |
659 | ||
660 | ret = lttcomm_send_unix_sock(socket, buffer.data, buffer.size); | |
a58c490f JG |
661 | if (ret < 0) { |
662 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
663 | goto end_unlock; | |
664 | } | |
665 | ||
666 | ret = receive_command_reply(channel, &status); | |
667 | if (ret < 0) { | |
668 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
669 | goto end_unlock; | |
670 | } | |
671 | end_unlock: | |
672 | pthread_mutex_unlock(&channel->lock); | |
673 | end: | |
3647288f | 674 | lttng_dynamic_buffer_reset(&buffer); |
a58c490f JG |
675 | return status; |
676 | } | |
677 | ||
678 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
679 | struct lttng_notification_channel *channel, | |
680 | const struct lttng_condition *condition) | |
681 | { | |
682 | return send_condition_command(channel, | |
683 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
684 | condition); | |
685 | } | |
686 | ||
687 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
688 | struct lttng_notification_channel *channel, | |
689 | const struct lttng_condition *condition) | |
690 | { | |
691 | return send_condition_command(channel, | |
692 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
693 | condition); | |
694 | } | |
695 | ||
696 | void lttng_notification_channel_destroy( | |
697 | struct lttng_notification_channel *channel) | |
698 | { | |
699 | if (!channel) { | |
700 | return; | |
701 | } | |
702 | ||
703 | if (channel->socket >= 0) { | |
704 | (void) lttcomm_close_unix_sock(channel->socket); | |
705 | } | |
706 | pthread_mutex_destroy(&channel->lock); | |
707 | lttng_dynamic_buffer_reset(&channel->reception_buffer); | |
708 | free(channel); | |
709 | } |