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