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 | ||
4301861c JG |
57 | if (msg.size == 0) { |
58 | goto skip_payload; | |
59 | } | |
60 | ||
a58c490f JG |
61 | /* Reserve space for the payload. */ |
62 | ret = lttng_dynamic_buffer_set_size(&channel->reception_buffer, | |
63 | channel->reception_buffer.size + msg.size); | |
64 | if (ret) { | |
65 | goto error; | |
66 | } | |
67 | ||
68 | /* Receive message payload. */ | |
69 | ret = lttcomm_recv_unix_sock(channel->socket, | |
70 | channel->reception_buffer.data + sizeof(msg), msg.size); | |
71 | if (ret < (ssize_t) msg.size) { | |
72 | ret = -1; | |
73 | goto error; | |
74 | } | |
4301861c JG |
75 | |
76 | skip_payload: | |
a58c490f JG |
77 | ret = 0; |
78 | end: | |
79 | return ret; | |
80 | error: | |
e4f3498e JG |
81 | if (lttng_dynamic_buffer_set_size(&channel->reception_buffer, 0)) { |
82 | ret = -1; | |
83 | } | |
a58c490f JG |
84 | goto end; |
85 | } | |
86 | ||
87 | static | |
88 | enum lttng_notification_channel_message_type get_current_message_type( | |
89 | struct lttng_notification_channel *channel) | |
90 | { | |
91 | struct lttng_notification_channel_message *msg; | |
92 | ||
93 | assert(channel->reception_buffer.size >= sizeof(*msg)); | |
94 | ||
95 | msg = (struct lttng_notification_channel_message *) | |
96 | channel->reception_buffer.data; | |
97 | return (enum lttng_notification_channel_message_type) msg->type; | |
98 | } | |
99 | ||
100 | static | |
101 | struct lttng_notification *create_notification_from_current_message( | |
102 | struct lttng_notification_channel *channel) | |
103 | { | |
104 | ssize_t ret; | |
105 | struct lttng_notification *notification = NULL; | |
106 | struct lttng_buffer_view view; | |
107 | ||
108 | if (channel->reception_buffer.size <= | |
109 | sizeof(struct lttng_notification_channel_message)) { | |
110 | goto end; | |
111 | } | |
112 | ||
113 | view = lttng_buffer_view_from_dynamic_buffer(&channel->reception_buffer, | |
114 | sizeof(struct lttng_notification_channel_message), -1); | |
115 | ||
116 | ret = lttng_notification_create_from_buffer(&view, ¬ification); | |
117 | if (ret != channel->reception_buffer.size - | |
118 | sizeof(struct lttng_notification_channel_message)) { | |
119 | lttng_notification_destroy(notification); | |
120 | notification = NULL; | |
121 | goto end; | |
122 | } | |
123 | end: | |
124 | return notification; | |
125 | } | |
126 | ||
127 | struct lttng_notification_channel *lttng_notification_channel_create( | |
128 | struct lttng_endpoint *endpoint) | |
129 | { | |
130 | int fd, ret; | |
131 | bool is_in_tracing_group = false, is_root = false; | |
132 | char *sock_path = NULL; | |
133 | struct lttng_notification_channel *channel = NULL; | |
134 | ||
135 | if (!endpoint || | |
136 | endpoint != lttng_session_daemon_notification_endpoint) { | |
137 | goto end; | |
138 | } | |
139 | ||
140 | sock_path = zmalloc(LTTNG_PATH_MAX); | |
141 | if (!sock_path) { | |
142 | goto end; | |
143 | } | |
144 | ||
145 | channel = zmalloc(sizeof(struct lttng_notification_channel)); | |
146 | if (!channel) { | |
147 | goto end; | |
148 | } | |
149 | channel->socket = -1; | |
150 | pthread_mutex_init(&channel->lock, NULL); | |
151 | lttng_dynamic_buffer_init(&channel->reception_buffer); | |
152 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); | |
153 | ||
154 | is_root = (getuid() == 0); | |
155 | if (!is_root) { | |
156 | is_in_tracing_group = lttng_check_tracing_group(); | |
157 | } | |
158 | ||
159 | if (is_root || is_in_tracing_group) { | |
1da0efb1 | 160 | ret = lttng_strncpy(sock_path, |
a58c490f JG |
161 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, |
162 | LTTNG_PATH_MAX); | |
1da0efb1 JG |
163 | if (ret) { |
164 | ret = -LTTNG_ERR_INVALID; | |
165 | goto error; | |
166 | } | |
167 | ||
a58c490f JG |
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; | |
d977a743 | 214 | struct lttng_poll_event events; |
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 | /* | |
d977a743 MD |
244 | * Block on interruptible epoll/poll() instead of the message reception |
245 | * itself as the recvmsg() wrappers always restart on EINTR. We choose | |
246 | * to wait using interruptible epoll/poll() in order to: | |
f83bcd90 JG |
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 | */ | |
d977a743 MD |
255 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
256 | if (ret < 0) { | |
257 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
258 | goto end_unlock; | |
259 | } | |
260 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
261 | if (ret < 0) { | |
262 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
263 | goto end_clean_poll; | |
264 | } | |
265 | ret = lttng_poll_wait_interruptible(&events, -1); | |
266 | if (ret <= 0) { | |
267 | status = (ret == -1 && errno == EINTR) ? | |
f83bcd90 JG |
268 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : |
269 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 270 | goto end_clean_poll; |
a58c490f JG |
271 | } |
272 | ||
a58c490f JG |
273 | ret = receive_message(channel); |
274 | if (ret) { | |
275 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 276 | goto end_clean_poll; |
a58c490f JG |
277 | } |
278 | ||
279 | switch (get_current_message_type(channel)) { | |
280 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
281 | notification = create_notification_from_current_message( | |
282 | channel); | |
283 | if (!notification) { | |
284 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 285 | goto end_clean_poll; |
a58c490f JG |
286 | } |
287 | break; | |
288 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
289 | /* No payload to consume. */ | |
290 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
291 | break; | |
292 | default: | |
293 | /* Protocol error. */ | |
294 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 295 | goto end_clean_poll; |
a58c490f JG |
296 | } |
297 | ||
d977a743 MD |
298 | end_clean_poll: |
299 | lttng_poll_clean(&events); | |
a58c490f JG |
300 | end_unlock: |
301 | pthread_mutex_unlock(&channel->lock); | |
a57a7f22 | 302 | *_notification = notification; |
a58c490f | 303 | end: |
a58c490f JG |
304 | return status; |
305 | } | |
306 | ||
307 | static | |
308 | int enqueue_dropped_notification( | |
309 | struct lttng_notification_channel *channel) | |
310 | { | |
311 | int ret = 0; | |
312 | struct pending_notification *pending_notification; | |
313 | struct cds_list_head *last_element = | |
314 | channel->pending_notifications.list.prev; | |
315 | ||
316 | pending_notification = caa_container_of(last_element, | |
317 | struct pending_notification, node); | |
318 | if (!pending_notification->notification) { | |
319 | /* | |
320 | * The last enqueued notification indicates dropped | |
321 | * notifications; there is nothing to do as we group | |
322 | * dropped notifications together. | |
323 | */ | |
324 | goto end; | |
325 | } | |
326 | ||
327 | if (channel->pending_notifications.count >= | |
328 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
329 | pending_notification->notification) { | |
330 | /* | |
331 | * Discard the last enqueued notification to indicate | |
332 | * that notifications were dropped at this point. | |
333 | */ | |
334 | lttng_notification_destroy( | |
335 | pending_notification->notification); | |
336 | pending_notification->notification = NULL; | |
337 | goto end; | |
338 | } | |
339 | ||
340 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
341 | if (!pending_notification) { | |
342 | ret = -1; | |
343 | goto end; | |
344 | } | |
345 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
346 | cds_list_add(&pending_notification->node, | |
347 | &channel->pending_notifications.list); | |
348 | channel->pending_notifications.count++; | |
349 | end: | |
350 | return ret; | |
351 | } | |
352 | ||
353 | static | |
354 | int enqueue_notification_from_current_message( | |
355 | struct lttng_notification_channel *channel) | |
356 | { | |
357 | int ret = 0; | |
358 | struct lttng_notification *notification; | |
359 | struct pending_notification *pending_notification; | |
360 | ||
361 | if (channel->pending_notifications.count >= | |
362 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
363 | /* Drop the notification. */ | |
364 | ret = enqueue_dropped_notification(channel); | |
365 | goto end; | |
366 | } | |
367 | ||
368 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
369 | if (!pending_notification) { | |
370 | ret = -1; | |
371 | goto error; | |
372 | } | |
373 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
374 | ||
375 | notification = create_notification_from_current_message(channel); | |
376 | if (!notification) { | |
377 | ret = -1; | |
378 | goto error; | |
379 | } | |
380 | ||
381 | pending_notification->notification = notification; | |
382 | cds_list_add(&pending_notification->node, | |
383 | &channel->pending_notifications.list); | |
384 | channel->pending_notifications.count++; | |
385 | end: | |
386 | return ret; | |
387 | error: | |
388 | free(pending_notification); | |
389 | goto end; | |
390 | } | |
391 | ||
1d757b1c JG |
392 | enum lttng_notification_channel_status |
393 | lttng_notification_channel_has_pending_notification( | |
394 | struct lttng_notification_channel *channel, | |
395 | bool *_notification_pending) | |
396 | { | |
397 | int ret; | |
398 | enum lttng_notification_channel_status status = | |
399 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 400 | struct lttng_poll_event events; |
1d757b1c JG |
401 | |
402 | if (!channel || !_notification_pending) { | |
403 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
404 | goto end; | |
405 | } | |
406 | ||
407 | pthread_mutex_lock(&channel->lock); | |
408 | ||
409 | if (channel->pending_notifications.count) { | |
410 | *_notification_pending = true; | |
411 | goto end_unlock; | |
412 | } | |
413 | ||
414 | if (channel->socket < 0) { | |
415 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
416 | goto end_unlock; | |
417 | } | |
418 | ||
419 | /* | |
420 | * Check, without blocking, if data is available on the channel's | |
421 | * socket. If there is data available, it is safe to read (blocking) | |
422 | * on the socket for a message from the session daemon. | |
423 | * | |
424 | * Since all commands wait for the session daemon's reply before | |
425 | * releasing the channel's lock, the protocol only allows for | |
426 | * notifications and "notification dropped" messages to come | |
427 | * through. If we receive a different message type, it is | |
428 | * considered a protocol error. | |
429 | * | |
430 | * Note that this function is not guaranteed not to block. This | |
431 | * will block until our peer (the session daemon) has sent a complete | |
432 | * message if we see data available on the socket. If the peer does | |
433 | * not respect the protocol, this may block indefinitely. | |
434 | */ | |
d977a743 MD |
435 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
436 | if (ret < 0) { | |
437 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
438 | goto end_unlock; | |
439 | } | |
440 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
441 | if (ret < 0) { | |
442 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
443 | goto end_clean_poll; | |
444 | } | |
445 | /* timeout = 0: return immediately. */ | |
446 | ret = lttng_poll_wait_interruptible(&events, 0); | |
1d757b1c JG |
447 | if (ret == 0) { |
448 | /* No data available. */ | |
449 | *_notification_pending = false; | |
d977a743 | 450 | goto end_clean_poll; |
1d757b1c JG |
451 | } else if (ret < 0) { |
452 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 453 | goto end_clean_poll; |
1d757b1c JG |
454 | } |
455 | ||
456 | /* Data available on socket. */ | |
457 | ret = receive_message(channel); | |
458 | if (ret) { | |
459 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 460 | goto end_clean_poll; |
1d757b1c JG |
461 | } |
462 | ||
463 | switch (get_current_message_type(channel)) { | |
464 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
465 | ret = enqueue_notification_from_current_message(channel); | |
466 | if (ret) { | |
d977a743 | 467 | goto end_clean_poll; |
1d757b1c JG |
468 | } |
469 | *_notification_pending = true; | |
470 | break; | |
471 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
472 | ret = enqueue_dropped_notification(channel); | |
473 | if (ret) { | |
d977a743 | 474 | goto end_clean_poll; |
1d757b1c JG |
475 | } |
476 | *_notification_pending = true; | |
477 | break; | |
478 | default: | |
479 | /* Protocol error. */ | |
480 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 481 | goto end_clean_poll; |
1d757b1c JG |
482 | } |
483 | ||
d977a743 MD |
484 | end_clean_poll: |
485 | lttng_poll_clean(&events); | |
1d757b1c JG |
486 | end_unlock: |
487 | pthread_mutex_unlock(&channel->lock); | |
488 | end: | |
489 | return status; | |
490 | } | |
491 | ||
a58c490f JG |
492 | static |
493 | int receive_command_reply(struct lttng_notification_channel *channel, | |
494 | enum lttng_notification_channel_status *status) | |
495 | { | |
496 | int ret; | |
497 | struct lttng_notification_channel_command_reply *reply; | |
498 | ||
499 | while (true) { | |
500 | enum lttng_notification_channel_message_type msg_type; | |
501 | ||
502 | ret = receive_message(channel); | |
503 | if (ret) { | |
504 | goto end; | |
505 | } | |
506 | ||
507 | msg_type = get_current_message_type(channel); | |
508 | switch (msg_type) { | |
509 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
510 | goto exit_loop; | |
511 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
512 | ret = enqueue_notification_from_current_message( | |
513 | channel); | |
514 | if (ret) { | |
515 | goto end; | |
516 | } | |
517 | break; | |
518 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
519 | ret = enqueue_dropped_notification(channel); | |
520 | if (ret) { | |
521 | goto end; | |
522 | } | |
523 | break; | |
524 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
525 | { | |
526 | struct lttng_notification_channel_command_handshake *handshake; | |
527 | ||
528 | handshake = (struct lttng_notification_channel_command_handshake *) | |
529 | (channel->reception_buffer.data + | |
530 | sizeof(struct lttng_notification_channel_message)); | |
531 | channel->version.major = handshake->major; | |
532 | channel->version.minor = handshake->minor; | |
533 | channel->version.set = true; | |
534 | break; | |
535 | } | |
536 | default: | |
537 | ret = -1; | |
538 | goto end; | |
539 | } | |
540 | } | |
541 | ||
542 | exit_loop: | |
543 | if (channel->reception_buffer.size < | |
544 | (sizeof(struct lttng_notification_channel_message) + | |
545 | sizeof(*reply))) { | |
546 | /* Invalid message received. */ | |
547 | ret = -1; | |
548 | goto end; | |
549 | } | |
550 | ||
551 | reply = (struct lttng_notification_channel_command_reply *) | |
552 | (channel->reception_buffer.data + | |
553 | sizeof(struct lttng_notification_channel_message)); | |
554 | *status = (enum lttng_notification_channel_status) reply->status; | |
555 | end: | |
556 | return ret; | |
557 | } | |
558 | ||
559 | static | |
560 | int handshake(struct lttng_notification_channel *channel) | |
561 | { | |
562 | ssize_t ret; | |
563 | enum lttng_notification_channel_status status = | |
564 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
565 | struct lttng_notification_channel_command_handshake handshake = { | |
566 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
567 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
568 | }; | |
569 | struct lttng_notification_channel_message msg_header = { | |
570 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
571 | .size = sizeof(handshake), | |
572 | }; | |
573 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
574 | ||
575 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
576 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
577 | ||
578 | pthread_mutex_lock(&channel->lock); | |
579 | ||
01ea340e | 580 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
581 | sizeof(send_buffer)); |
582 | if (ret < 0) { | |
583 | goto end_unlock; | |
584 | } | |
585 | ||
586 | /* Receive handshake info from the sessiond. */ | |
587 | ret = receive_command_reply(channel, &status); | |
588 | if (ret < 0) { | |
589 | goto end_unlock; | |
590 | } | |
591 | ||
592 | if (!channel->version.set) { | |
593 | ret = -1; | |
594 | goto end_unlock; | |
595 | } | |
596 | ||
597 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
598 | ret = -1; | |
599 | goto end_unlock; | |
600 | } | |
601 | ||
602 | end_unlock: | |
603 | pthread_mutex_unlock(&channel->lock); | |
604 | return ret; | |
605 | } | |
606 | ||
607 | static | |
608 | enum lttng_notification_channel_status send_condition_command( | |
609 | struct lttng_notification_channel *channel, | |
610 | enum lttng_notification_channel_message_type type, | |
611 | const struct lttng_condition *condition) | |
612 | { | |
613 | int socket; | |
3647288f | 614 | ssize_t ret; |
a58c490f JG |
615 | enum lttng_notification_channel_status status = |
616 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
3647288f JG |
617 | struct lttng_dynamic_buffer buffer; |
618 | struct lttng_notification_channel_message cmd_header = { | |
619 | .type = (int8_t) type, | |
a58c490f JG |
620 | }; |
621 | ||
3647288f JG |
622 | lttng_dynamic_buffer_init(&buffer); |
623 | ||
a58c490f JG |
624 | if (!channel) { |
625 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
626 | goto end; | |
627 | } | |
628 | ||
629 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
630 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
631 | ||
632 | pthread_mutex_lock(&channel->lock); | |
633 | socket = channel->socket; | |
634 | if (!lttng_condition_validate(condition)) { | |
635 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
636 | goto end_unlock; | |
637 | } | |
638 | ||
3647288f JG |
639 | ret = lttng_dynamic_buffer_append(&buffer, &cmd_header, |
640 | sizeof(cmd_header)); | |
641 | if (ret) { | |
642 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
643 | goto end_unlock; |
644 | } | |
645 | ||
3647288f JG |
646 | ret = lttng_condition_serialize(condition, &buffer); |
647 | if (ret) { | |
648 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
649 | goto end_unlock; |
650 | } | |
651 | ||
3647288f JG |
652 | /* Update payload length. */ |
653 | ((struct lttng_notification_channel_message *) buffer.data)->size = | |
654 | (uint32_t) (buffer.size - sizeof(cmd_header)); | |
655 | ||
656 | ret = lttcomm_send_unix_sock(socket, buffer.data, buffer.size); | |
a58c490f JG |
657 | if (ret < 0) { |
658 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
659 | goto end_unlock; | |
660 | } | |
661 | ||
662 | ret = receive_command_reply(channel, &status); | |
663 | if (ret < 0) { | |
664 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
665 | goto end_unlock; | |
666 | } | |
667 | end_unlock: | |
668 | pthread_mutex_unlock(&channel->lock); | |
669 | end: | |
3647288f | 670 | lttng_dynamic_buffer_reset(&buffer); |
a58c490f JG |
671 | return status; |
672 | } | |
673 | ||
674 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
675 | struct lttng_notification_channel *channel, | |
676 | const struct lttng_condition *condition) | |
677 | { | |
678 | return send_condition_command(channel, | |
679 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
680 | condition); | |
681 | } | |
682 | ||
683 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
684 | struct lttng_notification_channel *channel, | |
685 | const struct lttng_condition *condition) | |
686 | { | |
687 | return send_condition_command(channel, | |
688 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
689 | condition); | |
690 | } | |
691 | ||
692 | void lttng_notification_channel_destroy( | |
693 | struct lttng_notification_channel *channel) | |
694 | { | |
695 | if (!channel) { | |
696 | return; | |
697 | } | |
698 | ||
699 | if (channel->socket >= 0) { | |
700 | (void) lttcomm_close_unix_sock(channel->socket); | |
701 | } | |
702 | pthread_mutex_destroy(&channel->lock); | |
703 | lttng_dynamic_buffer_reset(&channel->reception_buffer); | |
704 | free(channel); | |
705 | } |