Commit | Line | Data |
---|---|---|
a58c490f | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
a58c490f | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
a58c490f | 5 | * |
a58c490f JG |
6 | */ |
7 | ||
8 | #include <lttng/notification/notification-internal.h> | |
9 | #include <lttng/notification/channel-internal.h> | |
10 | #include <lttng/condition/condition-internal.h> | |
11 | #include <lttng/endpoint.h> | |
12 | #include <common/defaults.h> | |
13 | #include <common/error.h> | |
14 | #include <common/dynamic-buffer.h> | |
15 | #include <common/utils.h> | |
16 | #include <common/defaults.h> | |
17 | #include <assert.h> | |
18 | #include "lttng-ctl-helper.h" | |
d977a743 | 19 | #include <common/compat/poll.h> |
a58c490f JG |
20 | |
21 | static | |
22 | int handshake(struct lttng_notification_channel *channel); | |
23 | ||
24 | /* | |
25 | * Populates the reception buffer with the next complete message. | |
1d757b1c | 26 | * The caller must acquire the channel's lock. |
a58c490f JG |
27 | */ |
28 | static | |
29 | int receive_message(struct lttng_notification_channel *channel) | |
30 | { | |
31 | ssize_t ret; | |
32 | struct lttng_notification_channel_message msg; | |
33 | ||
1d757b1c JG |
34 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
35 | ret = -1; | |
36 | goto end; | |
a58c490f JG |
37 | } |
38 | ||
39 | ret = lttcomm_recv_unix_sock(channel->socket, &msg, sizeof(msg)); | |
40 | if (ret <= 0) { | |
41 | ret = -1; | |
42 | goto error; | |
43 | } | |
44 | ||
45 | if (msg.size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
46 | ret = -1; | |
47 | goto error; | |
48 | } | |
49 | ||
50 | /* Add message header at buffer's start. */ | |
51 | ret = lttng_dynamic_buffer_append(&channel->reception_buffer, &msg, | |
52 | sizeof(msg)); | |
53 | if (ret) { | |
54 | goto error; | |
55 | } | |
56 | ||
57 | /* Reserve space for the payload. */ | |
58 | ret = lttng_dynamic_buffer_set_size(&channel->reception_buffer, | |
59 | channel->reception_buffer.size + msg.size); | |
60 | if (ret) { | |
61 | goto error; | |
62 | } | |
63 | ||
64 | /* Receive message payload. */ | |
65 | ret = lttcomm_recv_unix_sock(channel->socket, | |
66 | channel->reception_buffer.data + sizeof(msg), msg.size); | |
67 | if (ret < (ssize_t) msg.size) { | |
68 | ret = -1; | |
69 | goto error; | |
70 | } | |
71 | ret = 0; | |
72 | end: | |
73 | return ret; | |
74 | error: | |
e4f3498e JG |
75 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
76 | ret = -1; | |
77 | } | |
a58c490f JG |
78 | goto end; |
79 | } | |
80 | ||
81 | static | |
82 | enum lttng_notification_channel_message_type get_current_message_type( | |
83 | struct lttng_notification_channel *channel) | |
84 | { | |
85 | struct lttng_notification_channel_message *msg; | |
86 | ||
87 | assert(channel->reception_buffer.size >= sizeof(*msg)); | |
88 | ||
89 | msg = (struct lttng_notification_channel_message *) | |
90 | channel->reception_buffer.data; | |
91 | return (enum lttng_notification_channel_message_type) msg->type; | |
92 | } | |
93 | ||
94 | static | |
95 | struct lttng_notification *create_notification_from_current_message( | |
96 | struct lttng_notification_channel *channel) | |
97 | { | |
98 | ssize_t ret; | |
99 | struct lttng_notification *notification = NULL; | |
a58c490f JG |
100 | |
101 | if (channel->reception_buffer.size <= | |
102 | sizeof(struct lttng_notification_channel_message)) { | |
103 | goto end; | |
104 | } | |
105 | ||
c0a66c84 JG |
106 | { |
107 | struct lttng_payload_view view = lttng_payload_view_from_dynamic_buffer( | |
108 | &channel->reception_buffer, | |
109 | sizeof(struct lttng_notification_channel_message), | |
110 | -1); | |
111 | ||
112 | ret = lttng_notification_create_from_payload( | |
113 | &view, ¬ification); | |
114 | } | |
a58c490f | 115 | |
a58c490f JG |
116 | if (ret != channel->reception_buffer.size - |
117 | sizeof(struct lttng_notification_channel_message)) { | |
118 | lttng_notification_destroy(notification); | |
119 | notification = NULL; | |
120 | goto end; | |
121 | } | |
122 | end: | |
123 | return notification; | |
124 | } | |
125 | ||
126 | struct lttng_notification_channel *lttng_notification_channel_create( | |
127 | struct lttng_endpoint *endpoint) | |
128 | { | |
129 | int fd, ret; | |
130 | bool is_in_tracing_group = false, is_root = false; | |
131 | char *sock_path = NULL; | |
132 | struct lttng_notification_channel *channel = NULL; | |
133 | ||
134 | if (!endpoint || | |
135 | endpoint != lttng_session_daemon_notification_endpoint) { | |
136 | goto end; | |
137 | } | |
138 | ||
139 | sock_path = zmalloc(LTTNG_PATH_MAX); | |
140 | if (!sock_path) { | |
141 | goto end; | |
142 | } | |
143 | ||
144 | channel = zmalloc(sizeof(struct lttng_notification_channel)); | |
145 | if (!channel) { | |
146 | goto end; | |
147 | } | |
148 | channel->socket = -1; | |
149 | pthread_mutex_init(&channel->lock, NULL); | |
150 | lttng_dynamic_buffer_init(&channel->reception_buffer); | |
151 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); | |
152 | ||
153 | is_root = (getuid() == 0); | |
154 | if (!is_root) { | |
155 | is_in_tracing_group = lttng_check_tracing_group(); | |
156 | } | |
157 | ||
158 | if (is_root || is_in_tracing_group) { | |
159 | lttng_ctl_copy_string(sock_path, | |
160 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
161 | LTTNG_PATH_MAX); | |
162 | ret = lttcomm_connect_unix_sock(sock_path); | |
163 | if (ret >= 0) { | |
164 | fd = ret; | |
165 | goto set_fd; | |
166 | } | |
167 | } | |
168 | ||
169 | /* Fallback to local session daemon. */ | |
170 | ret = snprintf(sock_path, LTTNG_PATH_MAX, | |
171 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
172 | utils_get_home_dir()); | |
173 | if (ret < 0 || ret >= LTTNG_PATH_MAX) { | |
174 | goto error; | |
175 | } | |
176 | ||
177 | ret = lttcomm_connect_unix_sock(sock_path); | |
178 | if (ret < 0) { | |
179 | goto error; | |
180 | } | |
181 | fd = ret; | |
182 | ||
183 | set_fd: | |
184 | channel->socket = fd; | |
185 | ||
186 | ret = handshake(channel); | |
187 | if (ret) { | |
188 | goto error; | |
189 | } | |
190 | end: | |
191 | free(sock_path); | |
192 | return channel; | |
193 | error: | |
194 | lttng_notification_channel_destroy(channel); | |
195 | channel = NULL; | |
196 | goto end; | |
197 | } | |
198 | ||
199 | enum lttng_notification_channel_status | |
200 | lttng_notification_channel_get_next_notification( | |
201 | struct lttng_notification_channel *channel, | |
202 | struct lttng_notification **_notification) | |
203 | { | |
204 | int ret; | |
205 | struct lttng_notification *notification = NULL; | |
206 | enum lttng_notification_channel_status status = | |
207 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 208 | struct lttng_poll_event events; |
a58c490f JG |
209 | |
210 | if (!channel || !_notification) { | |
211 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
212 | goto end; | |
213 | } | |
214 | ||
94a61469 JG |
215 | pthread_mutex_lock(&channel->lock); |
216 | ||
a58c490f JG |
217 | if (channel->pending_notifications.count) { |
218 | struct pending_notification *pending_notification; | |
219 | ||
220 | assert(!cds_list_empty(&channel->pending_notifications.list)); | |
221 | ||
222 | /* Deliver one of the pending notifications. */ | |
223 | pending_notification = cds_list_first_entry( | |
224 | &channel->pending_notifications.list, | |
225 | struct pending_notification, | |
226 | node); | |
227 | notification = pending_notification->notification; | |
228 | if (!notification) { | |
229 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
230 | } | |
231 | cds_list_del(&pending_notification->node); | |
232 | channel->pending_notifications.count--; | |
233 | free(pending_notification); | |
94a61469 | 234 | goto end_unlock; |
f83bcd90 JG |
235 | } |
236 | ||
237 | /* | |
d977a743 MD |
238 | * Block on interruptible epoll/poll() instead of the message reception |
239 | * itself as the recvmsg() wrappers always restart on EINTR. We choose | |
240 | * to wait using interruptible epoll/poll() in order to: | |
f83bcd90 JG |
241 | * 1) Return if a signal occurs, |
242 | * 2) Not deal with partially received messages. | |
243 | * | |
244 | * The drawback to this approach is that we assume that messages | |
245 | * are complete/well formed. If a message is shorter than its | |
246 | * announced length, receive_message() will block on recvmsg() | |
247 | * and never return (even if a signal is received). | |
248 | */ | |
d977a743 MD |
249 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
250 | if (ret < 0) { | |
251 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
252 | goto end_unlock; | |
253 | } | |
254 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
255 | if (ret < 0) { | |
256 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
257 | goto end_clean_poll; | |
258 | } | |
259 | ret = lttng_poll_wait_interruptible(&events, -1); | |
260 | if (ret <= 0) { | |
261 | status = (ret == -1 && errno == EINTR) ? | |
f83bcd90 JG |
262 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : |
263 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 264 | goto end_clean_poll; |
a58c490f JG |
265 | } |
266 | ||
a58c490f JG |
267 | ret = receive_message(channel); |
268 | if (ret) { | |
269 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 270 | goto end_clean_poll; |
a58c490f JG |
271 | } |
272 | ||
273 | switch (get_current_message_type(channel)) { | |
274 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
275 | notification = create_notification_from_current_message( | |
276 | channel); | |
277 | if (!notification) { | |
278 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 279 | goto end_clean_poll; |
a58c490f JG |
280 | } |
281 | break; | |
282 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
283 | /* No payload to consume. */ | |
284 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
285 | break; | |
286 | default: | |
287 | /* Protocol error. */ | |
288 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 289 | goto end_clean_poll; |
a58c490f JG |
290 | } |
291 | ||
d977a743 MD |
292 | end_clean_poll: |
293 | lttng_poll_clean(&events); | |
a58c490f JG |
294 | end_unlock: |
295 | pthread_mutex_unlock(&channel->lock); | |
a57a7f22 | 296 | *_notification = notification; |
a58c490f | 297 | end: |
a58c490f JG |
298 | return status; |
299 | } | |
300 | ||
301 | static | |
302 | int enqueue_dropped_notification( | |
303 | struct lttng_notification_channel *channel) | |
304 | { | |
305 | int ret = 0; | |
306 | struct pending_notification *pending_notification; | |
307 | struct cds_list_head *last_element = | |
308 | channel->pending_notifications.list.prev; | |
309 | ||
310 | pending_notification = caa_container_of(last_element, | |
311 | struct pending_notification, node); | |
312 | if (!pending_notification->notification) { | |
313 | /* | |
314 | * The last enqueued notification indicates dropped | |
315 | * notifications; there is nothing to do as we group | |
316 | * dropped notifications together. | |
317 | */ | |
318 | goto end; | |
319 | } | |
320 | ||
321 | if (channel->pending_notifications.count >= | |
322 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
323 | pending_notification->notification) { | |
324 | /* | |
325 | * Discard the last enqueued notification to indicate | |
326 | * that notifications were dropped at this point. | |
327 | */ | |
328 | lttng_notification_destroy( | |
329 | pending_notification->notification); | |
330 | pending_notification->notification = NULL; | |
331 | goto end; | |
332 | } | |
333 | ||
334 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
335 | if (!pending_notification) { | |
336 | ret = -1; | |
337 | goto end; | |
338 | } | |
339 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
340 | cds_list_add(&pending_notification->node, | |
341 | &channel->pending_notifications.list); | |
342 | channel->pending_notifications.count++; | |
343 | end: | |
344 | return ret; | |
345 | } | |
346 | ||
347 | static | |
348 | int enqueue_notification_from_current_message( | |
349 | struct lttng_notification_channel *channel) | |
350 | { | |
351 | int ret = 0; | |
352 | struct lttng_notification *notification; | |
353 | struct pending_notification *pending_notification; | |
354 | ||
355 | if (channel->pending_notifications.count >= | |
356 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
357 | /* Drop the notification. */ | |
358 | ret = enqueue_dropped_notification(channel); | |
359 | goto end; | |
360 | } | |
361 | ||
362 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
363 | if (!pending_notification) { | |
364 | ret = -1; | |
365 | goto error; | |
366 | } | |
367 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
368 | ||
369 | notification = create_notification_from_current_message(channel); | |
370 | if (!notification) { | |
371 | ret = -1; | |
372 | goto error; | |
373 | } | |
374 | ||
375 | pending_notification->notification = notification; | |
376 | cds_list_add(&pending_notification->node, | |
377 | &channel->pending_notifications.list); | |
378 | channel->pending_notifications.count++; | |
379 | end: | |
380 | return ret; | |
381 | error: | |
382 | free(pending_notification); | |
383 | goto end; | |
384 | } | |
385 | ||
1d757b1c JG |
386 | enum lttng_notification_channel_status |
387 | lttng_notification_channel_has_pending_notification( | |
388 | struct lttng_notification_channel *channel, | |
389 | bool *_notification_pending) | |
390 | { | |
391 | int ret; | |
392 | enum lttng_notification_channel_status status = | |
393 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 394 | struct lttng_poll_event events; |
1d757b1c JG |
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 | */ | |
d977a743 MD |
429 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
430 | if (ret < 0) { | |
431 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
432 | goto end_unlock; | |
433 | } | |
434 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
435 | if (ret < 0) { | |
436 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
437 | goto end_clean_poll; | |
438 | } | |
439 | /* timeout = 0: return immediately. */ | |
440 | ret = lttng_poll_wait_interruptible(&events, 0); | |
1d757b1c JG |
441 | if (ret == 0) { |
442 | /* No data available. */ | |
443 | *_notification_pending = false; | |
d977a743 | 444 | goto end_clean_poll; |
1d757b1c JG |
445 | } else if (ret < 0) { |
446 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 447 | goto end_clean_poll; |
1d757b1c JG |
448 | } |
449 | ||
450 | /* Data available on socket. */ | |
451 | ret = receive_message(channel); | |
452 | if (ret) { | |
453 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 454 | goto end_clean_poll; |
1d757b1c JG |
455 | } |
456 | ||
457 | switch (get_current_message_type(channel)) { | |
458 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
459 | ret = enqueue_notification_from_current_message(channel); | |
460 | if (ret) { | |
d977a743 | 461 | goto end_clean_poll; |
1d757b1c JG |
462 | } |
463 | *_notification_pending = true; | |
464 | break; | |
465 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
466 | ret = enqueue_dropped_notification(channel); | |
467 | if (ret) { | |
d977a743 | 468 | goto end_clean_poll; |
1d757b1c JG |
469 | } |
470 | *_notification_pending = true; | |
471 | break; | |
472 | default: | |
473 | /* Protocol error. */ | |
474 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 475 | goto end_clean_poll; |
1d757b1c JG |
476 | } |
477 | ||
d977a743 MD |
478 | end_clean_poll: |
479 | lttng_poll_clean(&events); | |
1d757b1c JG |
480 | end_unlock: |
481 | pthread_mutex_unlock(&channel->lock); | |
482 | end: | |
483 | return status; | |
484 | } | |
485 | ||
a58c490f JG |
486 | static |
487 | int receive_command_reply(struct lttng_notification_channel *channel, | |
488 | enum lttng_notification_channel_status *status) | |
489 | { | |
490 | int ret; | |
491 | struct lttng_notification_channel_command_reply *reply; | |
492 | ||
493 | while (true) { | |
494 | enum lttng_notification_channel_message_type msg_type; | |
495 | ||
496 | ret = receive_message(channel); | |
497 | if (ret) { | |
498 | goto end; | |
499 | } | |
500 | ||
501 | msg_type = get_current_message_type(channel); | |
502 | switch (msg_type) { | |
503 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
504 | goto exit_loop; | |
505 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
506 | ret = enqueue_notification_from_current_message( | |
507 | channel); | |
508 | if (ret) { | |
509 | goto end; | |
510 | } | |
511 | break; | |
512 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
513 | ret = enqueue_dropped_notification(channel); | |
514 | if (ret) { | |
515 | goto end; | |
516 | } | |
517 | break; | |
518 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
519 | { | |
520 | struct lttng_notification_channel_command_handshake *handshake; | |
521 | ||
522 | handshake = (struct lttng_notification_channel_command_handshake *) | |
523 | (channel->reception_buffer.data + | |
524 | sizeof(struct lttng_notification_channel_message)); | |
525 | channel->version.major = handshake->major; | |
526 | channel->version.minor = handshake->minor; | |
527 | channel->version.set = true; | |
528 | break; | |
529 | } | |
530 | default: | |
531 | ret = -1; | |
532 | goto end; | |
533 | } | |
534 | } | |
535 | ||
536 | exit_loop: | |
537 | if (channel->reception_buffer.size < | |
538 | (sizeof(struct lttng_notification_channel_message) + | |
539 | sizeof(*reply))) { | |
540 | /* Invalid message received. */ | |
541 | ret = -1; | |
542 | goto end; | |
543 | } | |
544 | ||
545 | reply = (struct lttng_notification_channel_command_reply *) | |
546 | (channel->reception_buffer.data + | |
547 | sizeof(struct lttng_notification_channel_message)); | |
548 | *status = (enum lttng_notification_channel_status) reply->status; | |
549 | end: | |
550 | return ret; | |
551 | } | |
552 | ||
553 | static | |
554 | int handshake(struct lttng_notification_channel *channel) | |
555 | { | |
556 | ssize_t ret; | |
557 | enum lttng_notification_channel_status status = | |
558 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
559 | struct lttng_notification_channel_command_handshake handshake = { | |
560 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
561 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
562 | }; | |
563 | struct lttng_notification_channel_message msg_header = { | |
564 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
565 | .size = sizeof(handshake), | |
566 | }; | |
567 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
568 | ||
569 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
570 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
571 | ||
572 | pthread_mutex_lock(&channel->lock); | |
573 | ||
01ea340e | 574 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
575 | sizeof(send_buffer)); |
576 | if (ret < 0) { | |
577 | goto end_unlock; | |
578 | } | |
579 | ||
580 | /* Receive handshake info from the sessiond. */ | |
581 | ret = receive_command_reply(channel, &status); | |
582 | if (ret < 0) { | |
583 | goto end_unlock; | |
584 | } | |
585 | ||
586 | if (!channel->version.set) { | |
587 | ret = -1; | |
588 | goto end_unlock; | |
589 | } | |
590 | ||
591 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
592 | ret = -1; | |
593 | goto end_unlock; | |
594 | } | |
595 | ||
596 | end_unlock: | |
597 | pthread_mutex_unlock(&channel->lock); | |
598 | return ret; | |
599 | } | |
600 | ||
601 | static | |
602 | enum lttng_notification_channel_status send_condition_command( | |
603 | struct lttng_notification_channel *channel, | |
604 | enum lttng_notification_channel_message_type type, | |
605 | const struct lttng_condition *condition) | |
606 | { | |
607 | int socket; | |
3647288f | 608 | ssize_t ret; |
a58c490f JG |
609 | enum lttng_notification_channel_status status = |
610 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
c0a66c84 | 611 | struct lttng_payload payload; |
3647288f JG |
612 | struct lttng_notification_channel_message cmd_header = { |
613 | .type = (int8_t) type, | |
a58c490f JG |
614 | }; |
615 | ||
c0a66c84 | 616 | lttng_payload_init(&payload); |
3647288f | 617 | |
a58c490f JG |
618 | if (!channel) { |
619 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
620 | goto end; | |
621 | } | |
622 | ||
623 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
624 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
625 | ||
626 | pthread_mutex_lock(&channel->lock); | |
627 | socket = channel->socket; | |
628 | if (!lttng_condition_validate(condition)) { | |
629 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
630 | goto end_unlock; | |
631 | } | |
632 | ||
c0a66c84 | 633 | ret = lttng_dynamic_buffer_append(&payload.buffer, &cmd_header, |
3647288f JG |
634 | sizeof(cmd_header)); |
635 | if (ret) { | |
636 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
637 | goto end_unlock; |
638 | } | |
639 | ||
c0a66c84 | 640 | ret = lttng_condition_serialize(condition, &payload); |
3647288f JG |
641 | if (ret) { |
642 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
643 | goto end_unlock; |
644 | } | |
645 | ||
3647288f | 646 | /* Update payload length. */ |
c0a66c84 JG |
647 | ((struct lttng_notification_channel_message *) payload.buffer.data)->size = |
648 | (uint32_t) (payload.buffer.size - sizeof(cmd_header)); | |
3647288f | 649 | |
c0a66c84 JG |
650 | ret = lttcomm_send_unix_sock( |
651 | socket, payload.buffer.data, payload.buffer.size); | |
a58c490f JG |
652 | if (ret < 0) { |
653 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
654 | goto end_unlock; | |
655 | } | |
656 | ||
657 | ret = receive_command_reply(channel, &status); | |
658 | if (ret < 0) { | |
659 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
660 | goto end_unlock; | |
661 | } | |
662 | end_unlock: | |
663 | pthread_mutex_unlock(&channel->lock); | |
664 | end: | |
c0a66c84 | 665 | lttng_payload_reset(&payload); |
a58c490f JG |
666 | return status; |
667 | } | |
668 | ||
669 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
670 | struct lttng_notification_channel *channel, | |
671 | const struct lttng_condition *condition) | |
672 | { | |
673 | return send_condition_command(channel, | |
674 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
675 | condition); | |
676 | } | |
677 | ||
678 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
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_UNSUBSCRIBE, | |
684 | condition); | |
685 | } | |
686 | ||
687 | void lttng_notification_channel_destroy( | |
688 | struct lttng_notification_channel *channel) | |
689 | { | |
690 | if (!channel) { | |
691 | return; | |
692 | } | |
693 | ||
694 | if (channel->socket >= 0) { | |
695 | (void) lttcomm_close_unix_sock(channel->socket); | |
696 | } | |
697 | pthread_mutex_destroy(&channel->lock); | |
698 | lttng_dynamic_buffer_reset(&channel->reception_buffer); | |
699 | free(channel); | |
700 | } |