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> | |
882093ee JR |
17 | #include <common/payload.h> |
18 | #include <common/payload-view.h> | |
19 | #include <common/unix.h> | |
a58c490f JG |
20 | #include <assert.h> |
21 | #include "lttng-ctl-helper.h" | |
d977a743 | 22 | #include <common/compat/poll.h> |
a58c490f JG |
23 | |
24 | static | |
25 | int handshake(struct lttng_notification_channel *channel); | |
26 | ||
27 | /* | |
28 | * Populates the reception buffer with the next complete message. | |
1d757b1c | 29 | * The caller must acquire the channel's lock. |
a58c490f JG |
30 | */ |
31 | static | |
32 | int receive_message(struct lttng_notification_channel *channel) | |
33 | { | |
34 | ssize_t ret; | |
35 | struct lttng_notification_channel_message msg; | |
36 | ||
882093ee | 37 | lttng_payload_clear(&channel->reception_payload); |
a58c490f JG |
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. */ | |
882093ee | 51 | ret = lttng_dynamic_buffer_append(&channel->reception_payload.buffer, &msg, |
a58c490f JG |
52 | sizeof(msg)); |
53 | if (ret) { | |
54 | goto error; | |
55 | } | |
56 | ||
57 | /* Reserve space for the payload. */ | |
882093ee JR |
58 | ret = lttng_dynamic_buffer_set_size(&channel->reception_payload.buffer, |
59 | channel->reception_payload.buffer.size + msg.size); | |
a58c490f JG |
60 | if (ret) { |
61 | goto error; | |
62 | } | |
63 | ||
64 | /* Receive message payload. */ | |
65 | ret = lttcomm_recv_unix_sock(channel->socket, | |
882093ee | 66 | channel->reception_payload.buffer.data + sizeof(msg), msg.size); |
a58c490f JG |
67 | if (ret < (ssize_t) msg.size) { |
68 | ret = -1; | |
69 | goto error; | |
70 | } | |
882093ee JR |
71 | |
72 | /* Receive message fds. */ | |
73 | if (msg.fds != 0) { | |
74 | ret = lttcomm_recv_payload_fds_unix_sock(channel->socket, | |
75 | msg.fds, &channel->reception_payload); | |
76 | if (ret < sizeof(int) * msg.fds) { | |
77 | ret = -1; | |
78 | goto error; | |
79 | } | |
80 | } | |
a58c490f JG |
81 | ret = 0; |
82 | end: | |
83 | return ret; | |
84 | error: | |
882093ee | 85 | lttng_payload_clear(&channel->reception_payload); |
a58c490f JG |
86 | goto end; |
87 | } | |
88 | ||
89 | static | |
90 | enum lttng_notification_channel_message_type get_current_message_type( | |
91 | struct lttng_notification_channel *channel) | |
92 | { | |
93 | struct lttng_notification_channel_message *msg; | |
94 | ||
882093ee | 95 | assert(channel->reception_payload.buffer.size >= sizeof(*msg)); |
a58c490f JG |
96 | |
97 | msg = (struct lttng_notification_channel_message *) | |
882093ee | 98 | channel->reception_payload.buffer.data; |
a58c490f JG |
99 | return (enum lttng_notification_channel_message_type) msg->type; |
100 | } | |
101 | ||
102 | static | |
103 | struct lttng_notification *create_notification_from_current_message( | |
104 | struct lttng_notification_channel *channel) | |
105 | { | |
106 | ssize_t ret; | |
107 | struct lttng_notification *notification = NULL; | |
a58c490f | 108 | |
882093ee | 109 | if (channel->reception_payload.buffer.size <= |
a58c490f JG |
110 | sizeof(struct lttng_notification_channel_message)) { |
111 | goto end; | |
112 | } | |
113 | ||
c0a66c84 | 114 | { |
882093ee JR |
115 | struct lttng_payload_view view = lttng_payload_view_from_payload( |
116 | &channel->reception_payload, | |
c0a66c84 JG |
117 | sizeof(struct lttng_notification_channel_message), |
118 | -1); | |
119 | ||
120 | ret = lttng_notification_create_from_payload( | |
121 | &view, ¬ification); | |
122 | } | |
a58c490f | 123 | |
882093ee | 124 | if (ret != channel->reception_payload.buffer.size - |
a58c490f JG |
125 | sizeof(struct lttng_notification_channel_message)) { |
126 | lttng_notification_destroy(notification); | |
127 | notification = NULL; | |
128 | goto end; | |
129 | } | |
130 | end: | |
131 | return notification; | |
132 | } | |
133 | ||
134 | struct lttng_notification_channel *lttng_notification_channel_create( | |
135 | struct lttng_endpoint *endpoint) | |
136 | { | |
137 | int fd, ret; | |
138 | bool is_in_tracing_group = false, is_root = false; | |
139 | char *sock_path = NULL; | |
140 | struct lttng_notification_channel *channel = NULL; | |
141 | ||
142 | if (!endpoint || | |
143 | endpoint != lttng_session_daemon_notification_endpoint) { | |
144 | goto end; | |
145 | } | |
146 | ||
147 | sock_path = zmalloc(LTTNG_PATH_MAX); | |
148 | if (!sock_path) { | |
149 | goto end; | |
150 | } | |
151 | ||
152 | channel = zmalloc(sizeof(struct lttng_notification_channel)); | |
153 | if (!channel) { | |
154 | goto end; | |
155 | } | |
156 | channel->socket = -1; | |
157 | pthread_mutex_init(&channel->lock, NULL); | |
882093ee | 158 | lttng_payload_init(&channel->reception_payload); |
a58c490f JG |
159 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); |
160 | ||
161 | is_root = (getuid() == 0); | |
162 | if (!is_root) { | |
163 | is_in_tracing_group = lttng_check_tracing_group(); | |
164 | } | |
165 | ||
166 | if (is_root || is_in_tracing_group) { | |
e1b624d0 | 167 | ret = lttng_strncpy(sock_path, |
a58c490f JG |
168 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, |
169 | LTTNG_PATH_MAX); | |
e1b624d0 JG |
170 | if (ret) { |
171 | ret = -LTTNG_ERR_INVALID; | |
172 | goto error; | |
173 | } | |
174 | ||
a58c490f JG |
175 | ret = lttcomm_connect_unix_sock(sock_path); |
176 | if (ret >= 0) { | |
177 | fd = ret; | |
178 | goto set_fd; | |
179 | } | |
180 | } | |
181 | ||
182 | /* Fallback to local session daemon. */ | |
183 | ret = snprintf(sock_path, LTTNG_PATH_MAX, | |
184 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
185 | utils_get_home_dir()); | |
186 | if (ret < 0 || ret >= LTTNG_PATH_MAX) { | |
187 | goto error; | |
188 | } | |
189 | ||
190 | ret = lttcomm_connect_unix_sock(sock_path); | |
191 | if (ret < 0) { | |
192 | goto error; | |
193 | } | |
194 | fd = ret; | |
195 | ||
196 | set_fd: | |
197 | channel->socket = fd; | |
198 | ||
199 | ret = handshake(channel); | |
200 | if (ret) { | |
201 | goto error; | |
202 | } | |
203 | end: | |
204 | free(sock_path); | |
205 | return channel; | |
206 | error: | |
207 | lttng_notification_channel_destroy(channel); | |
208 | channel = NULL; | |
209 | goto end; | |
210 | } | |
211 | ||
212 | enum lttng_notification_channel_status | |
213 | lttng_notification_channel_get_next_notification( | |
214 | struct lttng_notification_channel *channel, | |
215 | struct lttng_notification **_notification) | |
216 | { | |
217 | int ret; | |
218 | struct lttng_notification *notification = NULL; | |
219 | enum lttng_notification_channel_status status = | |
220 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 221 | struct lttng_poll_event events; |
a58c490f JG |
222 | |
223 | if (!channel || !_notification) { | |
224 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
225 | goto end; | |
226 | } | |
227 | ||
94a61469 JG |
228 | pthread_mutex_lock(&channel->lock); |
229 | ||
a58c490f JG |
230 | if (channel->pending_notifications.count) { |
231 | struct pending_notification *pending_notification; | |
232 | ||
233 | assert(!cds_list_empty(&channel->pending_notifications.list)); | |
234 | ||
235 | /* Deliver one of the pending notifications. */ | |
236 | pending_notification = cds_list_first_entry( | |
237 | &channel->pending_notifications.list, | |
238 | struct pending_notification, | |
239 | node); | |
240 | notification = pending_notification->notification; | |
241 | if (!notification) { | |
242 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
243 | } | |
244 | cds_list_del(&pending_notification->node); | |
245 | channel->pending_notifications.count--; | |
246 | free(pending_notification); | |
94a61469 | 247 | goto end_unlock; |
f83bcd90 JG |
248 | } |
249 | ||
250 | /* | |
d977a743 MD |
251 | * Block on interruptible epoll/poll() instead of the message reception |
252 | * itself as the recvmsg() wrappers always restart on EINTR. We choose | |
253 | * to wait using interruptible epoll/poll() in order to: | |
f83bcd90 JG |
254 | * 1) Return if a signal occurs, |
255 | * 2) Not deal with partially received messages. | |
256 | * | |
257 | * The drawback to this approach is that we assume that messages | |
258 | * are complete/well formed. If a message is shorter than its | |
259 | * announced length, receive_message() will block on recvmsg() | |
260 | * and never return (even if a signal is received). | |
261 | */ | |
d977a743 MD |
262 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
263 | if (ret < 0) { | |
264 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
265 | goto end_unlock; | |
266 | } | |
267 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
268 | if (ret < 0) { | |
269 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
270 | goto end_clean_poll; | |
271 | } | |
272 | ret = lttng_poll_wait_interruptible(&events, -1); | |
273 | if (ret <= 0) { | |
274 | status = (ret == -1 && errno == EINTR) ? | |
f83bcd90 JG |
275 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : |
276 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 277 | goto end_clean_poll; |
a58c490f JG |
278 | } |
279 | ||
a58c490f JG |
280 | ret = receive_message(channel); |
281 | if (ret) { | |
282 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 283 | goto end_clean_poll; |
a58c490f JG |
284 | } |
285 | ||
286 | switch (get_current_message_type(channel)) { | |
287 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
288 | notification = create_notification_from_current_message( | |
289 | channel); | |
290 | if (!notification) { | |
291 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 292 | goto end_clean_poll; |
a58c490f JG |
293 | } |
294 | break; | |
295 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
296 | /* No payload to consume. */ | |
297 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
298 | break; | |
299 | default: | |
300 | /* Protocol error. */ | |
301 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 302 | goto end_clean_poll; |
a58c490f JG |
303 | } |
304 | ||
d977a743 MD |
305 | end_clean_poll: |
306 | lttng_poll_clean(&events); | |
a58c490f JG |
307 | end_unlock: |
308 | pthread_mutex_unlock(&channel->lock); | |
a57a7f22 | 309 | *_notification = notification; |
a58c490f | 310 | end: |
a58c490f JG |
311 | return status; |
312 | } | |
313 | ||
314 | static | |
315 | int enqueue_dropped_notification( | |
316 | struct lttng_notification_channel *channel) | |
317 | { | |
318 | int ret = 0; | |
319 | struct pending_notification *pending_notification; | |
320 | struct cds_list_head *last_element = | |
321 | channel->pending_notifications.list.prev; | |
322 | ||
323 | pending_notification = caa_container_of(last_element, | |
324 | struct pending_notification, node); | |
325 | if (!pending_notification->notification) { | |
326 | /* | |
327 | * The last enqueued notification indicates dropped | |
328 | * notifications; there is nothing to do as we group | |
329 | * dropped notifications together. | |
330 | */ | |
331 | goto end; | |
332 | } | |
333 | ||
334 | if (channel->pending_notifications.count >= | |
335 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
336 | pending_notification->notification) { | |
337 | /* | |
338 | * Discard the last enqueued notification to indicate | |
339 | * that notifications were dropped at this point. | |
340 | */ | |
341 | lttng_notification_destroy( | |
342 | pending_notification->notification); | |
343 | pending_notification->notification = NULL; | |
344 | goto end; | |
345 | } | |
346 | ||
347 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
348 | if (!pending_notification) { | |
349 | ret = -1; | |
350 | goto end; | |
351 | } | |
352 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
353 | cds_list_add(&pending_notification->node, | |
354 | &channel->pending_notifications.list); | |
355 | channel->pending_notifications.count++; | |
356 | end: | |
357 | return ret; | |
358 | } | |
359 | ||
360 | static | |
361 | int enqueue_notification_from_current_message( | |
362 | struct lttng_notification_channel *channel) | |
363 | { | |
364 | int ret = 0; | |
365 | struct lttng_notification *notification; | |
366 | struct pending_notification *pending_notification; | |
367 | ||
368 | if (channel->pending_notifications.count >= | |
369 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
370 | /* Drop the notification. */ | |
371 | ret = enqueue_dropped_notification(channel); | |
372 | goto end; | |
373 | } | |
374 | ||
375 | pending_notification = zmalloc(sizeof(*pending_notification)); | |
376 | if (!pending_notification) { | |
377 | ret = -1; | |
378 | goto error; | |
379 | } | |
380 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
381 | ||
382 | notification = create_notification_from_current_message(channel); | |
383 | if (!notification) { | |
384 | ret = -1; | |
385 | goto error; | |
386 | } | |
387 | ||
388 | pending_notification->notification = notification; | |
389 | cds_list_add(&pending_notification->node, | |
390 | &channel->pending_notifications.list); | |
391 | channel->pending_notifications.count++; | |
392 | end: | |
393 | return ret; | |
394 | error: | |
395 | free(pending_notification); | |
396 | goto end; | |
397 | } | |
398 | ||
1d757b1c JG |
399 | enum lttng_notification_channel_status |
400 | lttng_notification_channel_has_pending_notification( | |
401 | struct lttng_notification_channel *channel, | |
402 | bool *_notification_pending) | |
403 | { | |
404 | int ret; | |
405 | enum lttng_notification_channel_status status = | |
406 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 407 | struct lttng_poll_event events; |
1d757b1c JG |
408 | |
409 | if (!channel || !_notification_pending) { | |
410 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
411 | goto end; | |
412 | } | |
413 | ||
414 | pthread_mutex_lock(&channel->lock); | |
415 | ||
416 | if (channel->pending_notifications.count) { | |
417 | *_notification_pending = true; | |
418 | goto end_unlock; | |
419 | } | |
420 | ||
421 | if (channel->socket < 0) { | |
422 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
423 | goto end_unlock; | |
424 | } | |
425 | ||
426 | /* | |
427 | * Check, without blocking, if data is available on the channel's | |
428 | * socket. If there is data available, it is safe to read (blocking) | |
429 | * on the socket for a message from the session daemon. | |
430 | * | |
431 | * Since all commands wait for the session daemon's reply before | |
432 | * releasing the channel's lock, the protocol only allows for | |
433 | * notifications and "notification dropped" messages to come | |
434 | * through. If we receive a different message type, it is | |
435 | * considered a protocol error. | |
436 | * | |
437 | * Note that this function is not guaranteed not to block. This | |
438 | * will block until our peer (the session daemon) has sent a complete | |
439 | * message if we see data available on the socket. If the peer does | |
440 | * not respect the protocol, this may block indefinitely. | |
441 | */ | |
d977a743 MD |
442 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
443 | if (ret < 0) { | |
444 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
445 | goto end_unlock; | |
446 | } | |
447 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
448 | if (ret < 0) { | |
449 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
450 | goto end_clean_poll; | |
451 | } | |
452 | /* timeout = 0: return immediately. */ | |
453 | ret = lttng_poll_wait_interruptible(&events, 0); | |
1d757b1c JG |
454 | if (ret == 0) { |
455 | /* No data available. */ | |
456 | *_notification_pending = false; | |
d977a743 | 457 | goto end_clean_poll; |
1d757b1c JG |
458 | } else if (ret < 0) { |
459 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 460 | goto end_clean_poll; |
1d757b1c JG |
461 | } |
462 | ||
463 | /* Data available on socket. */ | |
464 | ret = receive_message(channel); | |
465 | if (ret) { | |
466 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 467 | goto end_clean_poll; |
1d757b1c JG |
468 | } |
469 | ||
470 | switch (get_current_message_type(channel)) { | |
471 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
472 | ret = enqueue_notification_from_current_message(channel); | |
473 | if (ret) { | |
d977a743 | 474 | goto end_clean_poll; |
1d757b1c JG |
475 | } |
476 | *_notification_pending = true; | |
477 | break; | |
478 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
479 | ret = enqueue_dropped_notification(channel); | |
480 | if (ret) { | |
d977a743 | 481 | goto end_clean_poll; |
1d757b1c JG |
482 | } |
483 | *_notification_pending = true; | |
484 | break; | |
485 | default: | |
486 | /* Protocol error. */ | |
487 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 488 | goto end_clean_poll; |
1d757b1c JG |
489 | } |
490 | ||
d977a743 MD |
491 | end_clean_poll: |
492 | lttng_poll_clean(&events); | |
1d757b1c JG |
493 | end_unlock: |
494 | pthread_mutex_unlock(&channel->lock); | |
495 | end: | |
496 | return status; | |
497 | } | |
498 | ||
a58c490f JG |
499 | static |
500 | int receive_command_reply(struct lttng_notification_channel *channel, | |
501 | enum lttng_notification_channel_status *status) | |
502 | { | |
503 | int ret; | |
504 | struct lttng_notification_channel_command_reply *reply; | |
505 | ||
506 | while (true) { | |
507 | enum lttng_notification_channel_message_type msg_type; | |
508 | ||
509 | ret = receive_message(channel); | |
510 | if (ret) { | |
511 | goto end; | |
512 | } | |
513 | ||
514 | msg_type = get_current_message_type(channel); | |
515 | switch (msg_type) { | |
516 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
517 | goto exit_loop; | |
518 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
519 | ret = enqueue_notification_from_current_message( | |
520 | channel); | |
521 | if (ret) { | |
522 | goto end; | |
523 | } | |
524 | break; | |
525 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
526 | ret = enqueue_dropped_notification(channel); | |
527 | if (ret) { | |
528 | goto end; | |
529 | } | |
530 | break; | |
531 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
532 | { | |
533 | struct lttng_notification_channel_command_handshake *handshake; | |
534 | ||
535 | handshake = (struct lttng_notification_channel_command_handshake *) | |
882093ee | 536 | (channel->reception_payload.buffer.data + |
a58c490f JG |
537 | sizeof(struct lttng_notification_channel_message)); |
538 | channel->version.major = handshake->major; | |
539 | channel->version.minor = handshake->minor; | |
540 | channel->version.set = true; | |
541 | break; | |
542 | } | |
543 | default: | |
544 | ret = -1; | |
545 | goto end; | |
546 | } | |
547 | } | |
548 | ||
549 | exit_loop: | |
882093ee | 550 | if (channel->reception_payload.buffer.size < |
a58c490f JG |
551 | (sizeof(struct lttng_notification_channel_message) + |
552 | sizeof(*reply))) { | |
553 | /* Invalid message received. */ | |
554 | ret = -1; | |
555 | goto end; | |
556 | } | |
557 | ||
558 | reply = (struct lttng_notification_channel_command_reply *) | |
882093ee | 559 | (channel->reception_payload.buffer.data + |
a58c490f JG |
560 | sizeof(struct lttng_notification_channel_message)); |
561 | *status = (enum lttng_notification_channel_status) reply->status; | |
562 | end: | |
563 | return ret; | |
564 | } | |
565 | ||
566 | static | |
567 | int handshake(struct lttng_notification_channel *channel) | |
568 | { | |
569 | ssize_t ret; | |
570 | enum lttng_notification_channel_status status = | |
571 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
572 | struct lttng_notification_channel_command_handshake handshake = { | |
573 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
574 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
575 | }; | |
576 | struct lttng_notification_channel_message msg_header = { | |
577 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
578 | .size = sizeof(handshake), | |
579 | }; | |
580 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
581 | ||
582 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
583 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
584 | ||
585 | pthread_mutex_lock(&channel->lock); | |
586 | ||
01ea340e | 587 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
588 | sizeof(send_buffer)); |
589 | if (ret < 0) { | |
590 | goto end_unlock; | |
591 | } | |
592 | ||
593 | /* Receive handshake info from the sessiond. */ | |
594 | ret = receive_command_reply(channel, &status); | |
595 | if (ret < 0) { | |
596 | goto end_unlock; | |
597 | } | |
598 | ||
599 | if (!channel->version.set) { | |
600 | ret = -1; | |
601 | goto end_unlock; | |
602 | } | |
603 | ||
604 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
605 | ret = -1; | |
606 | goto end_unlock; | |
607 | } | |
608 | ||
609 | end_unlock: | |
610 | pthread_mutex_unlock(&channel->lock); | |
611 | return ret; | |
612 | } | |
613 | ||
614 | static | |
615 | enum lttng_notification_channel_status send_condition_command( | |
616 | struct lttng_notification_channel *channel, | |
617 | enum lttng_notification_channel_message_type type, | |
618 | const struct lttng_condition *condition) | |
619 | { | |
620 | int socket; | |
3647288f | 621 | ssize_t ret; |
a58c490f JG |
622 | enum lttng_notification_channel_status status = |
623 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
c0a66c84 | 624 | struct lttng_payload payload; |
3647288f JG |
625 | struct lttng_notification_channel_message cmd_header = { |
626 | .type = (int8_t) type, | |
a58c490f JG |
627 | }; |
628 | ||
c0a66c84 | 629 | lttng_payload_init(&payload); |
3647288f | 630 | |
a58c490f JG |
631 | if (!channel) { |
632 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
633 | goto end; | |
634 | } | |
635 | ||
636 | assert(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || | |
637 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); | |
638 | ||
639 | pthread_mutex_lock(&channel->lock); | |
640 | socket = channel->socket; | |
882093ee | 641 | |
a58c490f JG |
642 | if (!lttng_condition_validate(condition)) { |
643 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
644 | goto end_unlock; | |
645 | } | |
646 | ||
c0a66c84 | 647 | ret = lttng_dynamic_buffer_append(&payload.buffer, &cmd_header, |
3647288f JG |
648 | sizeof(cmd_header)); |
649 | if (ret) { | |
650 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
651 | goto end_unlock; |
652 | } | |
653 | ||
c0a66c84 | 654 | ret = lttng_condition_serialize(condition, &payload); |
3647288f JG |
655 | if (ret) { |
656 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
657 | goto end_unlock; |
658 | } | |
659 | ||
3647288f | 660 | /* Update payload length. */ |
c0a66c84 JG |
661 | ((struct lttng_notification_channel_message *) payload.buffer.data)->size = |
662 | (uint32_t) (payload.buffer.size - sizeof(cmd_header)); | |
3647288f | 663 | |
882093ee JR |
664 | { |
665 | struct lttng_payload_view pv = | |
666 | lttng_payload_view_from_payload( | |
667 | &payload, 0, -1); | |
668 | const int fd_count = | |
669 | lttng_payload_view_get_fd_handle_count(&pv); | |
670 | ||
671 | /* Update fd count. */ | |
672 | ((struct lttng_notification_channel_message *) payload.buffer.data)->fds = | |
673 | (uint32_t) fd_count; | |
674 | ||
675 | ret = lttcomm_send_unix_sock( | |
676 | socket, pv.buffer.data, pv.buffer.size); | |
677 | if (ret < 0) { | |
678 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
679 | goto end_unlock; | |
680 | } | |
681 | ||
682 | /* Pass fds if present. */ | |
683 | if (fd_count > 0) { | |
684 | ret = lttcomm_send_payload_view_fds_unix_sock(socket, | |
685 | &pv); | |
686 | if (ret < 0) { | |
687 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
688 | goto end_unlock; | |
689 | } | |
690 | } | |
a58c490f JG |
691 | } |
692 | ||
693 | ret = receive_command_reply(channel, &status); | |
694 | if (ret < 0) { | |
695 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
696 | goto end_unlock; | |
697 | } | |
698 | end_unlock: | |
699 | pthread_mutex_unlock(&channel->lock); | |
700 | end: | |
c0a66c84 | 701 | lttng_payload_reset(&payload); |
a58c490f JG |
702 | return status; |
703 | } | |
704 | ||
705 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
706 | struct lttng_notification_channel *channel, | |
707 | const struct lttng_condition *condition) | |
708 | { | |
709 | return send_condition_command(channel, | |
710 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
711 | condition); | |
712 | } | |
713 | ||
714 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
715 | struct lttng_notification_channel *channel, | |
716 | const struct lttng_condition *condition) | |
717 | { | |
718 | return send_condition_command(channel, | |
719 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
720 | condition); | |
721 | } | |
722 | ||
723 | void lttng_notification_channel_destroy( | |
724 | struct lttng_notification_channel *channel) | |
725 | { | |
726 | if (!channel) { | |
727 | return; | |
728 | } | |
729 | ||
730 | if (channel->socket >= 0) { | |
731 | (void) lttcomm_close_unix_sock(channel->socket); | |
732 | } | |
733 | pthread_mutex_destroy(&channel->lock); | |
882093ee | 734 | lttng_payload_reset(&channel->reception_payload); |
a58c490f JG |
735 | free(channel); |
736 | } |