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 | 20 | #include "lttng-ctl-helper.h" |
d977a743 | 21 | #include <common/compat/poll.h> |
a58c490f JG |
22 | |
23 | static | |
24 | int handshake(struct lttng_notification_channel *channel); | |
25 | ||
26 | /* | |
27 | * Populates the reception buffer with the next complete message. | |
1d757b1c | 28 | * The caller must acquire the channel's lock. |
a58c490f JG |
29 | */ |
30 | static | |
31 | int receive_message(struct lttng_notification_channel *channel) | |
32 | { | |
33 | ssize_t ret; | |
34 | struct lttng_notification_channel_message msg; | |
35 | ||
882093ee | 36 | lttng_payload_clear(&channel->reception_payload); |
a58c490f JG |
37 | |
38 | ret = lttcomm_recv_unix_sock(channel->socket, &msg, sizeof(msg)); | |
39 | if (ret <= 0) { | |
40 | ret = -1; | |
41 | goto error; | |
42 | } | |
43 | ||
44 | if (msg.size > DEFAULT_MAX_NOTIFICATION_CLIENT_MESSAGE_PAYLOAD_SIZE) { | |
45 | ret = -1; | |
46 | goto error; | |
47 | } | |
48 | ||
49 | /* Add message header at buffer's start. */ | |
882093ee | 50 | ret = lttng_dynamic_buffer_append(&channel->reception_payload.buffer, &msg, |
a58c490f JG |
51 | sizeof(msg)); |
52 | if (ret) { | |
53 | goto error; | |
54 | } | |
55 | ||
56 | /* Reserve space for the payload. */ | |
882093ee JR |
57 | ret = lttng_dynamic_buffer_set_size(&channel->reception_payload.buffer, |
58 | channel->reception_payload.buffer.size + msg.size); | |
a58c490f JG |
59 | if (ret) { |
60 | goto error; | |
61 | } | |
62 | ||
63 | /* Receive message payload. */ | |
64 | ret = lttcomm_recv_unix_sock(channel->socket, | |
882093ee | 65 | channel->reception_payload.buffer.data + sizeof(msg), msg.size); |
a58c490f JG |
66 | if (ret < (ssize_t) msg.size) { |
67 | ret = -1; | |
68 | goto error; | |
69 | } | |
882093ee JR |
70 | |
71 | /* Receive message fds. */ | |
72 | if (msg.fds != 0) { | |
73 | ret = lttcomm_recv_payload_fds_unix_sock(channel->socket, | |
74 | msg.fds, &channel->reception_payload); | |
75 | if (ret < sizeof(int) * msg.fds) { | |
76 | ret = -1; | |
77 | goto error; | |
78 | } | |
79 | } | |
a58c490f JG |
80 | ret = 0; |
81 | end: | |
82 | return ret; | |
83 | error: | |
882093ee | 84 | lttng_payload_clear(&channel->reception_payload); |
a58c490f JG |
85 | goto end; |
86 | } | |
87 | ||
88 | static | |
89 | enum lttng_notification_channel_message_type get_current_message_type( | |
90 | struct lttng_notification_channel *channel) | |
91 | { | |
92 | struct lttng_notification_channel_message *msg; | |
93 | ||
a0377dfe | 94 | LTTNG_ASSERT(channel->reception_payload.buffer.size >= sizeof(*msg)); |
a58c490f JG |
95 | |
96 | msg = (struct lttng_notification_channel_message *) | |
882093ee | 97 | channel->reception_payload.buffer.data; |
a58c490f JG |
98 | return (enum lttng_notification_channel_message_type) msg->type; |
99 | } | |
100 | ||
101 | static | |
102 | struct lttng_notification *create_notification_from_current_message( | |
103 | struct lttng_notification_channel *channel) | |
104 | { | |
105 | ssize_t ret; | |
106 | struct lttng_notification *notification = NULL; | |
a58c490f | 107 | |
882093ee | 108 | if (channel->reception_payload.buffer.size <= |
a58c490f JG |
109 | sizeof(struct lttng_notification_channel_message)) { |
110 | goto end; | |
111 | } | |
112 | ||
c0a66c84 | 113 | { |
882093ee JR |
114 | struct lttng_payload_view view = lttng_payload_view_from_payload( |
115 | &channel->reception_payload, | |
c0a66c84 JG |
116 | sizeof(struct lttng_notification_channel_message), |
117 | -1); | |
118 | ||
119 | ret = lttng_notification_create_from_payload( | |
120 | &view, ¬ification); | |
121 | } | |
a58c490f | 122 | |
882093ee | 123 | if (ret != channel->reception_payload.buffer.size - |
a58c490f JG |
124 | sizeof(struct lttng_notification_channel_message)) { |
125 | lttng_notification_destroy(notification); | |
126 | notification = NULL; | |
127 | goto end; | |
128 | } | |
129 | end: | |
130 | return notification; | |
131 | } | |
132 | ||
133 | struct lttng_notification_channel *lttng_notification_channel_create( | |
134 | struct lttng_endpoint *endpoint) | |
135 | { | |
136 | int fd, ret; | |
137 | bool is_in_tracing_group = false, is_root = false; | |
138 | char *sock_path = NULL; | |
139 | struct lttng_notification_channel *channel = NULL; | |
140 | ||
141 | if (!endpoint || | |
142 | endpoint != lttng_session_daemon_notification_endpoint) { | |
143 | goto end; | |
144 | } | |
145 | ||
4bd69c5f | 146 | sock_path = (char *) zmalloc(LTTNG_PATH_MAX); |
a58c490f JG |
147 | if (!sock_path) { |
148 | goto end; | |
149 | } | |
150 | ||
4bd69c5f | 151 | channel = (lttng_notification_channel *) zmalloc(sizeof(struct lttng_notification_channel)); |
a58c490f JG |
152 | if (!channel) { |
153 | goto end; | |
154 | } | |
155 | channel->socket = -1; | |
156 | pthread_mutex_init(&channel->lock, NULL); | |
882093ee | 157 | lttng_payload_init(&channel->reception_payload); |
a58c490f JG |
158 | CDS_INIT_LIST_HEAD(&channel->pending_notifications.list); |
159 | ||
160 | is_root = (getuid() == 0); | |
161 | if (!is_root) { | |
162 | is_in_tracing_group = lttng_check_tracing_group(); | |
163 | } | |
164 | ||
165 | if (is_root || is_in_tracing_group) { | |
e1b624d0 | 166 | ret = lttng_strncpy(sock_path, |
a58c490f JG |
167 | DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK, |
168 | LTTNG_PATH_MAX); | |
e1b624d0 JG |
169 | if (ret) { |
170 | ret = -LTTNG_ERR_INVALID; | |
171 | goto error; | |
172 | } | |
173 | ||
a58c490f JG |
174 | ret = lttcomm_connect_unix_sock(sock_path); |
175 | if (ret >= 0) { | |
176 | fd = ret; | |
177 | goto set_fd; | |
178 | } | |
179 | } | |
180 | ||
181 | /* Fallback to local session daemon. */ | |
182 | ret = snprintf(sock_path, LTTNG_PATH_MAX, | |
183 | DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK, | |
184 | utils_get_home_dir()); | |
185 | if (ret < 0 || ret >= LTTNG_PATH_MAX) { | |
186 | goto error; | |
187 | } | |
188 | ||
189 | ret = lttcomm_connect_unix_sock(sock_path); | |
190 | if (ret < 0) { | |
191 | goto error; | |
192 | } | |
193 | fd = ret; | |
194 | ||
195 | set_fd: | |
196 | channel->socket = fd; | |
197 | ||
198 | ret = handshake(channel); | |
199 | if (ret) { | |
200 | goto error; | |
201 | } | |
202 | end: | |
203 | free(sock_path); | |
204 | return channel; | |
205 | error: | |
206 | lttng_notification_channel_destroy(channel); | |
207 | channel = NULL; | |
208 | goto end; | |
209 | } | |
210 | ||
211 | enum lttng_notification_channel_status | |
212 | lttng_notification_channel_get_next_notification( | |
213 | struct lttng_notification_channel *channel, | |
214 | struct lttng_notification **_notification) | |
215 | { | |
216 | int ret; | |
217 | struct lttng_notification *notification = NULL; | |
218 | enum lttng_notification_channel_status status = | |
219 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 220 | struct lttng_poll_event events; |
a58c490f JG |
221 | |
222 | if (!channel || !_notification) { | |
223 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
224 | goto end; | |
225 | } | |
226 | ||
94a61469 JG |
227 | pthread_mutex_lock(&channel->lock); |
228 | ||
a58c490f JG |
229 | if (channel->pending_notifications.count) { |
230 | struct pending_notification *pending_notification; | |
231 | ||
a0377dfe | 232 | LTTNG_ASSERT(!cds_list_empty(&channel->pending_notifications.list)); |
a58c490f JG |
233 | |
234 | /* Deliver one of the pending notifications. */ | |
235 | pending_notification = cds_list_first_entry( | |
236 | &channel->pending_notifications.list, | |
237 | struct pending_notification, | |
238 | node); | |
239 | notification = pending_notification->notification; | |
240 | if (!notification) { | |
241 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
242 | } | |
243 | cds_list_del(&pending_notification->node); | |
244 | channel->pending_notifications.count--; | |
245 | free(pending_notification); | |
94a61469 | 246 | goto end_unlock; |
f83bcd90 JG |
247 | } |
248 | ||
249 | /* | |
d977a743 MD |
250 | * Block on interruptible epoll/poll() instead of the message reception |
251 | * itself as the recvmsg() wrappers always restart on EINTR. We choose | |
252 | * to wait using interruptible epoll/poll() in order to: | |
f83bcd90 JG |
253 | * 1) Return if a signal occurs, |
254 | * 2) Not deal with partially received messages. | |
255 | * | |
256 | * The drawback to this approach is that we assume that messages | |
257 | * are complete/well formed. If a message is shorter than its | |
258 | * announced length, receive_message() will block on recvmsg() | |
259 | * and never return (even if a signal is received). | |
260 | */ | |
d977a743 MD |
261 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
262 | if (ret < 0) { | |
263 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
264 | goto end_unlock; | |
265 | } | |
266 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
267 | if (ret < 0) { | |
268 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
269 | goto end_clean_poll; | |
270 | } | |
271 | ret = lttng_poll_wait_interruptible(&events, -1); | |
272 | if (ret <= 0) { | |
273 | status = (ret == -1 && errno == EINTR) ? | |
f83bcd90 JG |
274 | LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : |
275 | LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 276 | goto end_clean_poll; |
a58c490f JG |
277 | } |
278 | ||
a58c490f JG |
279 | ret = receive_message(channel); |
280 | if (ret) { | |
281 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 282 | goto end_clean_poll; |
a58c490f JG |
283 | } |
284 | ||
285 | switch (get_current_message_type(channel)) { | |
286 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
287 | notification = create_notification_from_current_message( | |
288 | channel); | |
289 | if (!notification) { | |
290 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 291 | goto end_clean_poll; |
a58c490f JG |
292 | } |
293 | break; | |
294 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
295 | /* No payload to consume. */ | |
296 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED; | |
297 | break; | |
298 | default: | |
299 | /* Protocol error. */ | |
300 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 301 | goto end_clean_poll; |
a58c490f JG |
302 | } |
303 | ||
d977a743 MD |
304 | end_clean_poll: |
305 | lttng_poll_clean(&events); | |
a58c490f JG |
306 | end_unlock: |
307 | pthread_mutex_unlock(&channel->lock); | |
a57a7f22 | 308 | *_notification = notification; |
a58c490f | 309 | end: |
a58c490f JG |
310 | return status; |
311 | } | |
312 | ||
313 | static | |
314 | int enqueue_dropped_notification( | |
315 | struct lttng_notification_channel *channel) | |
316 | { | |
317 | int ret = 0; | |
318 | struct pending_notification *pending_notification; | |
319 | struct cds_list_head *last_element = | |
320 | channel->pending_notifications.list.prev; | |
321 | ||
322 | pending_notification = caa_container_of(last_element, | |
323 | struct pending_notification, node); | |
324 | if (!pending_notification->notification) { | |
325 | /* | |
326 | * The last enqueued notification indicates dropped | |
327 | * notifications; there is nothing to do as we group | |
328 | * dropped notifications together. | |
329 | */ | |
330 | goto end; | |
331 | } | |
332 | ||
333 | if (channel->pending_notifications.count >= | |
334 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT && | |
335 | pending_notification->notification) { | |
336 | /* | |
337 | * Discard the last enqueued notification to indicate | |
338 | * that notifications were dropped at this point. | |
339 | */ | |
340 | lttng_notification_destroy( | |
341 | pending_notification->notification); | |
342 | pending_notification->notification = NULL; | |
343 | goto end; | |
344 | } | |
345 | ||
4bd69c5f | 346 | pending_notification = (struct pending_notification *) zmalloc(sizeof(*pending_notification)); |
a58c490f JG |
347 | if (!pending_notification) { |
348 | ret = -1; | |
349 | goto end; | |
350 | } | |
351 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
352 | cds_list_add(&pending_notification->node, | |
353 | &channel->pending_notifications.list); | |
354 | channel->pending_notifications.count++; | |
355 | end: | |
356 | return ret; | |
357 | } | |
358 | ||
359 | static | |
360 | int enqueue_notification_from_current_message( | |
361 | struct lttng_notification_channel *channel) | |
362 | { | |
363 | int ret = 0; | |
364 | struct lttng_notification *notification; | |
365 | struct pending_notification *pending_notification; | |
366 | ||
367 | if (channel->pending_notifications.count >= | |
368 | DEFAULT_CLIENT_MAX_QUEUED_NOTIFICATIONS_COUNT) { | |
369 | /* Drop the notification. */ | |
370 | ret = enqueue_dropped_notification(channel); | |
371 | goto end; | |
372 | } | |
373 | ||
4bd69c5f | 374 | pending_notification = (struct pending_notification *) zmalloc(sizeof(*pending_notification)); |
a58c490f JG |
375 | if (!pending_notification) { |
376 | ret = -1; | |
377 | goto error; | |
378 | } | |
379 | CDS_INIT_LIST_HEAD(&pending_notification->node); | |
380 | ||
381 | notification = create_notification_from_current_message(channel); | |
382 | if (!notification) { | |
383 | ret = -1; | |
384 | goto error; | |
385 | } | |
386 | ||
387 | pending_notification->notification = notification; | |
388 | cds_list_add(&pending_notification->node, | |
389 | &channel->pending_notifications.list); | |
390 | channel->pending_notifications.count++; | |
391 | end: | |
392 | return ret; | |
393 | error: | |
394 | free(pending_notification); | |
395 | goto end; | |
396 | } | |
397 | ||
1d757b1c JG |
398 | enum lttng_notification_channel_status |
399 | lttng_notification_channel_has_pending_notification( | |
400 | struct lttng_notification_channel *channel, | |
401 | bool *_notification_pending) | |
402 | { | |
403 | int ret; | |
404 | enum lttng_notification_channel_status status = | |
405 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
d977a743 | 406 | struct lttng_poll_event events; |
1d757b1c JG |
407 | |
408 | if (!channel || !_notification_pending) { | |
409 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
410 | goto end; | |
411 | } | |
412 | ||
413 | pthread_mutex_lock(&channel->lock); | |
414 | ||
415 | if (channel->pending_notifications.count) { | |
416 | *_notification_pending = true; | |
417 | goto end_unlock; | |
418 | } | |
419 | ||
420 | if (channel->socket < 0) { | |
421 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED; | |
422 | goto end_unlock; | |
423 | } | |
424 | ||
425 | /* | |
426 | * Check, without blocking, if data is available on the channel's | |
427 | * socket. If there is data available, it is safe to read (blocking) | |
428 | * on the socket for a message from the session daemon. | |
429 | * | |
430 | * Since all commands wait for the session daemon's reply before | |
431 | * releasing the channel's lock, the protocol only allows for | |
432 | * notifications and "notification dropped" messages to come | |
433 | * through. If we receive a different message type, it is | |
434 | * considered a protocol error. | |
435 | * | |
436 | * Note that this function is not guaranteed not to block. This | |
437 | * will block until our peer (the session daemon) has sent a complete | |
438 | * message if we see data available on the socket. If the peer does | |
439 | * not respect the protocol, this may block indefinitely. | |
440 | */ | |
d977a743 MD |
441 | ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); |
442 | if (ret < 0) { | |
443 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
444 | goto end_unlock; | |
445 | } | |
446 | ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); | |
447 | if (ret < 0) { | |
448 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
449 | goto end_clean_poll; | |
450 | } | |
451 | /* timeout = 0: return immediately. */ | |
452 | ret = lttng_poll_wait_interruptible(&events, 0); | |
1d757b1c JG |
453 | if (ret == 0) { |
454 | /* No data available. */ | |
455 | *_notification_pending = false; | |
d977a743 | 456 | goto end_clean_poll; |
1d757b1c JG |
457 | } else if (ret < 0) { |
458 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 459 | goto end_clean_poll; |
1d757b1c JG |
460 | } |
461 | ||
462 | /* Data available on socket. */ | |
463 | ret = receive_message(channel); | |
464 | if (ret) { | |
465 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 466 | goto end_clean_poll; |
1d757b1c JG |
467 | } |
468 | ||
469 | switch (get_current_message_type(channel)) { | |
470 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
471 | ret = enqueue_notification_from_current_message(channel); | |
472 | if (ret) { | |
d977a743 | 473 | goto end_clean_poll; |
1d757b1c JG |
474 | } |
475 | *_notification_pending = true; | |
476 | break; | |
477 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
478 | ret = enqueue_dropped_notification(channel); | |
479 | if (ret) { | |
d977a743 | 480 | goto end_clean_poll; |
1d757b1c JG |
481 | } |
482 | *_notification_pending = true; | |
483 | break; | |
484 | default: | |
485 | /* Protocol error. */ | |
486 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
d977a743 | 487 | goto end_clean_poll; |
1d757b1c JG |
488 | } |
489 | ||
d977a743 MD |
490 | end_clean_poll: |
491 | lttng_poll_clean(&events); | |
1d757b1c JG |
492 | end_unlock: |
493 | pthread_mutex_unlock(&channel->lock); | |
494 | end: | |
495 | return status; | |
496 | } | |
497 | ||
a58c490f JG |
498 | static |
499 | int receive_command_reply(struct lttng_notification_channel *channel, | |
500 | enum lttng_notification_channel_status *status) | |
501 | { | |
502 | int ret; | |
503 | struct lttng_notification_channel_command_reply *reply; | |
504 | ||
505 | while (true) { | |
506 | enum lttng_notification_channel_message_type msg_type; | |
507 | ||
508 | ret = receive_message(channel); | |
509 | if (ret) { | |
510 | goto end; | |
511 | } | |
512 | ||
513 | msg_type = get_current_message_type(channel); | |
514 | switch (msg_type) { | |
515 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_COMMAND_REPLY: | |
516 | goto exit_loop; | |
517 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: | |
518 | ret = enqueue_notification_from_current_message( | |
519 | channel); | |
520 | if (ret) { | |
521 | goto end; | |
522 | } | |
523 | break; | |
524 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: | |
525 | ret = enqueue_dropped_notification(channel); | |
526 | if (ret) { | |
527 | goto end; | |
528 | } | |
529 | break; | |
530 | case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE: | |
531 | { | |
532 | struct lttng_notification_channel_command_handshake *handshake; | |
533 | ||
534 | handshake = (struct lttng_notification_channel_command_handshake *) | |
882093ee | 535 | (channel->reception_payload.buffer.data + |
a58c490f JG |
536 | sizeof(struct lttng_notification_channel_message)); |
537 | channel->version.major = handshake->major; | |
538 | channel->version.minor = handshake->minor; | |
539 | channel->version.set = true; | |
540 | break; | |
541 | } | |
542 | default: | |
543 | ret = -1; | |
544 | goto end; | |
545 | } | |
546 | } | |
547 | ||
548 | exit_loop: | |
882093ee | 549 | if (channel->reception_payload.buffer.size < |
a58c490f JG |
550 | (sizeof(struct lttng_notification_channel_message) + |
551 | sizeof(*reply))) { | |
552 | /* Invalid message received. */ | |
553 | ret = -1; | |
554 | goto end; | |
555 | } | |
556 | ||
557 | reply = (struct lttng_notification_channel_command_reply *) | |
882093ee | 558 | (channel->reception_payload.buffer.data + |
a58c490f JG |
559 | sizeof(struct lttng_notification_channel_message)); |
560 | *status = (enum lttng_notification_channel_status) reply->status; | |
561 | end: | |
562 | return ret; | |
563 | } | |
564 | ||
565 | static | |
566 | int handshake(struct lttng_notification_channel *channel) | |
567 | { | |
568 | ssize_t ret; | |
569 | enum lttng_notification_channel_status status = | |
570 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
571 | struct lttng_notification_channel_command_handshake handshake = { | |
572 | .major = LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR, | |
573 | .minor = LTTNG_NOTIFICATION_CHANNEL_VERSION_MINOR, | |
574 | }; | |
575 | struct lttng_notification_channel_message msg_header = { | |
576 | .type = LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_HANDSHAKE, | |
577 | .size = sizeof(handshake), | |
578 | }; | |
579 | char send_buffer[sizeof(msg_header) + sizeof(handshake)]; | |
580 | ||
581 | memcpy(send_buffer, &msg_header, sizeof(msg_header)); | |
582 | memcpy(send_buffer + sizeof(msg_header), &handshake, sizeof(handshake)); | |
583 | ||
584 | pthread_mutex_lock(&channel->lock); | |
585 | ||
01ea340e | 586 | ret = lttcomm_send_creds_unix_sock(channel->socket, send_buffer, |
a58c490f JG |
587 | sizeof(send_buffer)); |
588 | if (ret < 0) { | |
589 | goto end_unlock; | |
590 | } | |
591 | ||
592 | /* Receive handshake info from the sessiond. */ | |
593 | ret = receive_command_reply(channel, &status); | |
594 | if (ret < 0) { | |
595 | goto end_unlock; | |
596 | } | |
597 | ||
598 | if (!channel->version.set) { | |
599 | ret = -1; | |
600 | goto end_unlock; | |
601 | } | |
602 | ||
603 | if (channel->version.major != LTTNG_NOTIFICATION_CHANNEL_VERSION_MAJOR) { | |
604 | ret = -1; | |
605 | goto end_unlock; | |
606 | } | |
607 | ||
608 | end_unlock: | |
609 | pthread_mutex_unlock(&channel->lock); | |
610 | return ret; | |
611 | } | |
612 | ||
613 | static | |
614 | enum lttng_notification_channel_status send_condition_command( | |
615 | struct lttng_notification_channel *channel, | |
616 | enum lttng_notification_channel_message_type type, | |
617 | const struct lttng_condition *condition) | |
618 | { | |
619 | int socket; | |
3647288f | 620 | ssize_t ret; |
a58c490f JG |
621 | enum lttng_notification_channel_status status = |
622 | LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; | |
c0a66c84 | 623 | struct lttng_payload payload; |
3647288f JG |
624 | struct lttng_notification_channel_message cmd_header = { |
625 | .type = (int8_t) type, | |
a58c490f JG |
626 | }; |
627 | ||
c0a66c84 | 628 | lttng_payload_init(&payload); |
3647288f | 629 | |
a58c490f JG |
630 | if (!channel) { |
631 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
632 | goto end; | |
633 | } | |
634 | ||
a0377dfe | 635 | LTTNG_ASSERT(type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE || |
a58c490f JG |
636 | type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE); |
637 | ||
638 | pthread_mutex_lock(&channel->lock); | |
639 | socket = channel->socket; | |
882093ee | 640 | |
a58c490f JG |
641 | if (!lttng_condition_validate(condition)) { |
642 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
643 | goto end_unlock; | |
644 | } | |
645 | ||
c0a66c84 | 646 | ret = lttng_dynamic_buffer_append(&payload.buffer, &cmd_header, |
3647288f JG |
647 | sizeof(cmd_header)); |
648 | if (ret) { | |
649 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
a58c490f JG |
650 | goto end_unlock; |
651 | } | |
652 | ||
c0a66c84 | 653 | ret = lttng_condition_serialize(condition, &payload); |
3647288f JG |
654 | if (ret) { |
655 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; | |
a58c490f JG |
656 | goto end_unlock; |
657 | } | |
658 | ||
3647288f | 659 | /* Update payload length. */ |
c0a66c84 JG |
660 | ((struct lttng_notification_channel_message *) payload.buffer.data)->size = |
661 | (uint32_t) (payload.buffer.size - sizeof(cmd_header)); | |
3647288f | 662 | |
882093ee JR |
663 | { |
664 | struct lttng_payload_view pv = | |
665 | lttng_payload_view_from_payload( | |
666 | &payload, 0, -1); | |
667 | const int fd_count = | |
668 | lttng_payload_view_get_fd_handle_count(&pv); | |
669 | ||
670 | /* Update fd count. */ | |
671 | ((struct lttng_notification_channel_message *) payload.buffer.data)->fds = | |
672 | (uint32_t) fd_count; | |
673 | ||
674 | ret = lttcomm_send_unix_sock( | |
675 | socket, pv.buffer.data, pv.buffer.size); | |
676 | if (ret < 0) { | |
677 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
678 | goto end_unlock; | |
679 | } | |
680 | ||
681 | /* Pass fds if present. */ | |
682 | if (fd_count > 0) { | |
683 | ret = lttcomm_send_payload_view_fds_unix_sock(socket, | |
684 | &pv); | |
685 | if (ret < 0) { | |
686 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
687 | goto end_unlock; | |
688 | } | |
689 | } | |
a58c490f JG |
690 | } |
691 | ||
692 | ret = receive_command_reply(channel, &status); | |
693 | if (ret < 0) { | |
694 | status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; | |
695 | goto end_unlock; | |
696 | } | |
697 | end_unlock: | |
698 | pthread_mutex_unlock(&channel->lock); | |
699 | end: | |
c0a66c84 | 700 | lttng_payload_reset(&payload); |
a58c490f JG |
701 | return status; |
702 | } | |
703 | ||
704 | enum lttng_notification_channel_status lttng_notification_channel_subscribe( | |
705 | struct lttng_notification_channel *channel, | |
706 | const struct lttng_condition *condition) | |
707 | { | |
708 | return send_condition_command(channel, | |
709 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE, | |
710 | condition); | |
711 | } | |
712 | ||
713 | enum lttng_notification_channel_status lttng_notification_channel_unsubscribe( | |
714 | struct lttng_notification_channel *channel, | |
715 | const struct lttng_condition *condition) | |
716 | { | |
717 | return send_condition_command(channel, | |
718 | LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_UNSUBSCRIBE, | |
719 | condition); | |
720 | } | |
721 | ||
722 | void lttng_notification_channel_destroy( | |
723 | struct lttng_notification_channel *channel) | |
724 | { | |
725 | if (!channel) { | |
726 | return; | |
727 | } | |
728 | ||
729 | if (channel->socket >= 0) { | |
730 | (void) lttcomm_close_unix_sock(channel->socket); | |
731 | } | |
732 | pthread_mutex_destroy(&channel->lock); | |
882093ee | 733 | lttng_payload_reset(&channel->reception_payload); |
a58c490f JG |
734 | free(channel); |
735 | } |