Fix: Relayd and consumerd socket leaks
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <assert.h>
20 #include <urcu/list.h>
21 #include <urcu/uatomic.h>
22
23 #include <common/defaults.h>
24 #include <common/common.h>
25 #include <common/sessiond-comm/sessiond-comm.h>
26 #include <common/relayd/relayd.h>
27
28 #include "channel.h"
29 #include "consumer.h"
30 #include "event.h"
31 #include "kernel.h"
32 #include "kernel-consumer.h"
33 #include "lttng-sessiond.h"
34 #include "utils.h"
35
36 #include "cmd.h"
37
38 /*
39 * Used to keep a unique index for each relayd socket created where this value
40 * is associated with streams on the consumer so it can match the right relayd
41 * to send to.
42 *
43 * This value should be incremented atomically for safety purposes and future
44 * possible concurrent access.
45 */
46 static unsigned int relayd_net_seq_idx;
47
48 /*
49 * Create a session path used by list_lttng_sessions for the case that the
50 * session consumer is on the network.
51 */
52 static int build_network_session_path(char *dst, size_t size,
53 struct ltt_session *session)
54 {
55 int ret, kdata_port, udata_port;
56 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
57 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
58
59 assert(session);
60 assert(dst);
61
62 memset(tmp_urls, 0, sizeof(tmp_urls));
63 memset(tmp_uurl, 0, sizeof(tmp_uurl));
64
65 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
66
67 if (session->kernel_session && session->kernel_session->consumer) {
68 kuri = &session->kernel_session->consumer->dst.net.control;
69 kdata_port = session->kernel_session->consumer->dst.net.data.port;
70 }
71
72 if (session->ust_session && session->ust_session->consumer) {
73 uuri = &session->ust_session->consumer->dst.net.control;
74 udata_port = session->ust_session->consumer->dst.net.data.port;
75 }
76
77 if (uuri == NULL && kuri == NULL) {
78 uri = &session->consumer->dst.net.control;
79 kdata_port = session->consumer->dst.net.data.port;
80 } else if (kuri && uuri) {
81 ret = uri_compare(kuri, uuri);
82 if (ret) {
83 /* Not Equal */
84 uri = kuri;
85 /* Build uuri URL string */
86 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
87 if (ret < 0) {
88 goto error;
89 }
90 } else {
91 uri = kuri;
92 }
93 } else if (kuri && uuri == NULL) {
94 uri = kuri;
95 } else if (uuri && kuri == NULL) {
96 uri = uuri;
97 }
98
99 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
100 if (ret < 0) {
101 goto error;
102 }
103
104 if (strlen(tmp_uurl) > 0) {
105 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
106 tmp_urls, kdata_port, tmp_uurl, udata_port);
107 } else {
108 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, kdata_port);
109 }
110
111 error:
112 return ret;
113 }
114
115 /*
116 * Fill lttng_channel array of all channels.
117 */
118 static void list_lttng_channels(int domain, struct ltt_session *session,
119 struct lttng_channel *channels)
120 {
121 int i = 0;
122 struct ltt_kernel_channel *kchan;
123
124 DBG("Listing channels for session %s", session->name);
125
126 switch (domain) {
127 case LTTNG_DOMAIN_KERNEL:
128 /* Kernel channels */
129 if (session->kernel_session != NULL) {
130 cds_list_for_each_entry(kchan,
131 &session->kernel_session->channel_list.head, list) {
132 /* Copy lttng_channel struct to array */
133 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
134 channels[i].enabled = kchan->enabled;
135 i++;
136 }
137 }
138 break;
139 case LTTNG_DOMAIN_UST:
140 {
141 struct lttng_ht_iter iter;
142 struct ltt_ust_channel *uchan;
143
144 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
145 &iter.iter, uchan, node.node) {
146 strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
147 channels[i].attr.overwrite = uchan->attr.overwrite;
148 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
149 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
150 channels[i].attr.switch_timer_interval =
151 uchan->attr.switch_timer_interval;
152 channels[i].attr.read_timer_interval =
153 uchan->attr.read_timer_interval;
154 channels[i].enabled = uchan->enabled;
155 switch (uchan->attr.output) {
156 case LTTNG_UST_MMAP:
157 default:
158 channels[i].attr.output = LTTNG_EVENT_MMAP;
159 break;
160 }
161 i++;
162 }
163 break;
164 }
165 default:
166 break;
167 }
168 }
169
170 /*
171 * Create a list of ust global domain events.
172 */
173 static int list_lttng_ust_global_events(char *channel_name,
174 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
175 {
176 int i = 0, ret = 0;
177 unsigned int nb_event = 0;
178 struct lttng_ht_iter iter;
179 struct lttng_ht_node_str *node;
180 struct ltt_ust_channel *uchan;
181 struct ltt_ust_event *uevent;
182 struct lttng_event *tmp;
183
184 DBG("Listing UST global events for channel %s", channel_name);
185
186 rcu_read_lock();
187
188 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
189 node = lttng_ht_iter_get_node_str(&iter);
190 if (node == NULL) {
191 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
192 goto error;
193 }
194
195 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
196
197 nb_event += lttng_ht_get_count(uchan->events);
198
199 if (nb_event == 0) {
200 ret = nb_event;
201 goto error;
202 }
203
204 DBG3("Listing UST global %d events", nb_event);
205
206 tmp = zmalloc(nb_event * sizeof(struct lttng_event));
207 if (tmp == NULL) {
208 ret = LTTNG_ERR_FATAL;
209 goto error;
210 }
211
212 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
213 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
214 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
215 tmp[i].enabled = uevent->enabled;
216
217 switch (uevent->attr.instrumentation) {
218 case LTTNG_UST_TRACEPOINT:
219 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
220 break;
221 case LTTNG_UST_PROBE:
222 tmp[i].type = LTTNG_EVENT_PROBE;
223 break;
224 case LTTNG_UST_FUNCTION:
225 tmp[i].type = LTTNG_EVENT_FUNCTION;
226 break;
227 }
228
229 tmp[i].loglevel = uevent->attr.loglevel;
230 switch (uevent->attr.loglevel_type) {
231 case LTTNG_UST_LOGLEVEL_ALL:
232 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
233 break;
234 case LTTNG_UST_LOGLEVEL_RANGE:
235 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
236 break;
237 case LTTNG_UST_LOGLEVEL_SINGLE:
238 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
239 break;
240 }
241 if (uevent->filter) {
242 tmp[i].filter = 1;
243 }
244 i++;
245 }
246
247 ret = nb_event;
248 *events = tmp;
249
250 error:
251 rcu_read_unlock();
252 return ret;
253 }
254
255 /*
256 * Fill lttng_event array of all kernel events in the channel.
257 */
258 static int list_lttng_kernel_events(char *channel_name,
259 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
260 {
261 int i = 0, ret;
262 unsigned int nb_event;
263 struct ltt_kernel_event *event;
264 struct ltt_kernel_channel *kchan;
265
266 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
267 if (kchan == NULL) {
268 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
269 goto error;
270 }
271
272 nb_event = kchan->event_count;
273
274 DBG("Listing events for channel %s", kchan->channel->name);
275
276 if (nb_event == 0) {
277 goto end;
278 }
279
280 *events = zmalloc(nb_event * sizeof(struct lttng_event));
281 if (*events == NULL) {
282 ret = LTTNG_ERR_FATAL;
283 goto error;
284 }
285
286 /* Kernel channels */
287 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
288 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
289 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
290 (*events)[i].enabled = event->enabled;
291
292 switch (event->event->instrumentation) {
293 case LTTNG_KERNEL_TRACEPOINT:
294 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
295 break;
296 case LTTNG_KERNEL_KPROBE:
297 case LTTNG_KERNEL_KRETPROBE:
298 (*events)[i].type = LTTNG_EVENT_PROBE;
299 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
300 sizeof(struct lttng_kernel_kprobe));
301 break;
302 case LTTNG_KERNEL_FUNCTION:
303 (*events)[i].type = LTTNG_EVENT_FUNCTION;
304 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
305 sizeof(struct lttng_kernel_function));
306 break;
307 case LTTNG_KERNEL_NOOP:
308 (*events)[i].type = LTTNG_EVENT_NOOP;
309 break;
310 case LTTNG_KERNEL_SYSCALL:
311 (*events)[i].type = LTTNG_EVENT_SYSCALL;
312 break;
313 case LTTNG_KERNEL_ALL:
314 assert(0);
315 break;
316 }
317 i++;
318 }
319
320 end:
321 return nb_event;
322
323 error:
324 /* Negate the error code to differentiate the size from an error */
325 return -ret;
326 }
327
328 /*
329 * Add URI so the consumer output object. Set the correct path depending on the
330 * domain adding the default trace directory.
331 */
332 static int add_uri_to_consumer(struct consumer_output *consumer,
333 struct lttng_uri *uri, int domain, const char *session_name)
334 {
335 int ret = LTTNG_OK;
336 const char *default_trace_dir;
337
338 assert(uri);
339
340 if (consumer == NULL) {
341 DBG("No consumer detected. Don't add URI. Stopping.");
342 ret = LTTNG_ERR_NO_CONSUMER;
343 goto error;
344 }
345
346 switch (domain) {
347 case LTTNG_DOMAIN_KERNEL:
348 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
349 break;
350 case LTTNG_DOMAIN_UST:
351 default_trace_dir = DEFAULT_UST_TRACE_DIR;
352 break;
353 default:
354 /*
355 * This case is possible is we try to add the URI to the global tracing
356 * session consumer object which in this case there is no subdir.
357 */
358 default_trace_dir = "";
359 }
360
361 switch (uri->dtype) {
362 case LTTNG_DST_IPV4:
363 case LTTNG_DST_IPV6:
364 DBG2("Setting network URI to consumer");
365
366 /* Set URI into consumer output object */
367 ret = consumer_set_network_uri(consumer, uri);
368 if (ret < 0) {
369 ret = LTTNG_ERR_FATAL;
370 goto error;
371 } else if (ret == 1) {
372 /*
373 * URI was the same in the consumer so we do not append the subdir
374 * again so to not duplicate output dir.
375 */
376 goto error;
377 }
378
379 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
380 ret = consumer_set_subdir(consumer, session_name);
381 if (ret < 0) {
382 ret = LTTNG_ERR_FATAL;
383 goto error;
384 }
385 }
386
387 if (uri->stype == LTTNG_STREAM_CONTROL) {
388 /* On a new subdir, reappend the default trace dir. */
389 strncat(consumer->subdir, default_trace_dir,
390 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
391 DBG3("Append domain trace name to subdir %s", consumer->subdir);
392 }
393
394 break;
395 case LTTNG_DST_PATH:
396 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
397 memset(consumer->dst.trace_path, 0,
398 sizeof(consumer->dst.trace_path));
399 strncpy(consumer->dst.trace_path, uri->dst.path,
400 sizeof(consumer->dst.trace_path));
401 /* Append default trace dir */
402 strncat(consumer->dst.trace_path, default_trace_dir,
403 sizeof(consumer->dst.trace_path) -
404 strlen(consumer->dst.trace_path) - 1);
405 /* Flag consumer as local. */
406 consumer->type = CONSUMER_DST_LOCAL;
407 break;
408 }
409
410 error:
411 return ret;
412 }
413
414 /*
415 * Init tracing by creating trace directory and sending fds kernel consumer.
416 */
417 static int init_kernel_tracing(struct ltt_kernel_session *session)
418 {
419 int ret = 0;
420 struct lttng_ht_iter iter;
421 struct consumer_socket *socket;
422
423 assert(session);
424
425 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
426 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
427 socket, node.node) {
428 /* Code flow error */
429 assert(socket->fd >= 0);
430
431 pthread_mutex_lock(socket->lock);
432 ret = kernel_consumer_send_session(socket->fd, session);
433 pthread_mutex_unlock(socket->lock);
434 if (ret < 0) {
435 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
436 goto error;
437 }
438 }
439 }
440
441 error:
442 return ret;
443 }
444
445 /*
446 * Create a socket to the relayd using the URI.
447 *
448 * On success, the relayd_sock pointer is set to the created socket.
449 * Else, it's stays untouched and a lttcomm error code is returned.
450 */
451 static int create_connect_relayd(struct consumer_output *output,
452 const char *session_name, struct lttng_uri *uri,
453 struct lttcomm_sock **relayd_sock)
454 {
455 int ret;
456 struct lttcomm_sock *sock;
457
458 /* Create socket object from URI */
459 sock = lttcomm_alloc_sock_from_uri(uri);
460 if (sock == NULL) {
461 ret = LTTNG_ERR_FATAL;
462 goto error;
463 }
464
465 ret = lttcomm_create_sock(sock);
466 if (ret < 0) {
467 ret = LTTNG_ERR_FATAL;
468 goto error;
469 }
470
471 /* Connect to relayd so we can proceed with a session creation. */
472 ret = relayd_connect(sock);
473 if (ret < 0) {
474 ERR("Unable to reach lttng-relayd");
475 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
476 goto free_sock;
477 }
478
479 /* Create socket for control stream. */
480 if (uri->stype == LTTNG_STREAM_CONTROL) {
481 DBG3("Creating relayd stream socket from URI");
482
483 /* Check relayd version */
484 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
485 RELAYD_VERSION_COMM_MINOR);
486 if (ret < 0) {
487 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
488 goto close_sock;
489 }
490 } else if (uri->stype == LTTNG_STREAM_DATA) {
491 DBG3("Creating relayd data socket from URI");
492 } else {
493 /* Command is not valid */
494 ERR("Relayd invalid stream type: %d", uri->stype);
495 ret = LTTNG_ERR_INVALID;
496 goto close_sock;
497 }
498
499 *relayd_sock = sock;
500
501 return LTTNG_OK;
502
503 close_sock:
504 if (sock) {
505 (void) relayd_close(sock);
506 }
507 free_sock:
508 if (sock) {
509 lttcomm_destroy_sock(sock);
510 }
511 error:
512 return ret;
513 }
514
515 /*
516 * Connect to the relayd using URI and send the socket to the right consumer.
517 */
518 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
519 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
520 int consumer_fd)
521 {
522 int ret;
523 struct lttcomm_sock *sock = NULL;
524
525 /* Don't resend the sockets to the consumer. */
526 if (consumer->dst.net.relayd_socks_sent) {
527 ret = LTTNG_OK;
528 goto error;
529 }
530
531 /* Set the network sequence index if not set. */
532 if (consumer->net_seq_index == -1) {
533 /*
534 * Increment net_seq_idx because we are about to transfer the
535 * new relayd socket to the consumer.
536 */
537 uatomic_inc(&relayd_net_seq_idx);
538 /* Assign unique key so the consumer can match streams */
539 uatomic_set(&consumer->net_seq_index,
540 uatomic_read(&relayd_net_seq_idx));
541 }
542
543 /* Connect to relayd and make version check if uri is the control. */
544 ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
545 if (ret != LTTNG_OK) {
546 goto close_sock;
547 }
548
549 /* If the control socket is connected, network session is ready */
550 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
551 session->net_handle = 1;
552 }
553
554 /* Send relayd socket to consumer. */
555 ret = consumer_send_relayd_socket(consumer_fd, sock,
556 consumer, relayd_uri->stype);
557 if (ret < 0) {
558 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
559 goto close_sock;
560 }
561
562 ret = LTTNG_OK;
563
564 /*
565 * Close socket which was dup on the consumer side. The session daemon does
566 * NOT keep track of the relayd socket(s) once transfer to the consumer.
567 */
568
569 close_sock:
570 if (sock) {
571 (void) relayd_close(sock);
572 lttcomm_destroy_sock(sock);
573 }
574
575 error:
576 return ret;
577 }
578
579 /*
580 * Send both relayd sockets to a specific consumer and domain. This is a
581 * helper function to facilitate sending the information to the consumer for a
582 * session.
583 */
584 static int send_consumer_relayd_sockets(int domain,
585 struct ltt_session *session, struct consumer_output *consumer, int fd)
586 {
587 int ret;
588
589 assert(session);
590 assert(consumer);
591
592 /* Don't resend the sockets to the consumer. */
593 if (consumer->dst.net.relayd_socks_sent) {
594 ret = LTTNG_OK;
595 goto error;
596 }
597
598 /* Sending control relayd socket. */
599 ret = send_consumer_relayd_socket(domain, session,
600 &consumer->dst.net.control, consumer, fd);
601 if (ret != LTTNG_OK) {
602 goto error;
603 }
604
605 /* Sending data relayd socket. */
606 ret = send_consumer_relayd_socket(domain, session,
607 &consumer->dst.net.data, consumer, fd);
608 if (ret != LTTNG_OK) {
609 goto error;
610 }
611
612 /* Flag that all relayd sockets were sent to the consumer. */
613 consumer->dst.net.relayd_socks_sent = 1;
614
615 error:
616 return ret;
617 }
618
619 /*
620 * Setup relayd connections for a tracing session. First creates the socket to
621 * the relayd and send them to the right domain consumer. Consumer type MUST be
622 * network.
623 */
624 static int setup_relayd(struct ltt_session *session)
625 {
626 int ret = LTTNG_OK;
627 struct ltt_ust_session *usess;
628 struct ltt_kernel_session *ksess;
629 struct consumer_socket *socket;
630 struct lttng_ht_iter iter;
631
632 assert(session);
633
634 usess = session->ust_session;
635 ksess = session->kernel_session;
636
637 DBG2("Setting relayd for session %s", session->name);
638
639 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
640 && usess->consumer->enabled) {
641 /* For each consumer socket, send relayd sockets */
642 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
643 socket, node.node) {
644 /* Code flow error */
645 assert(socket->fd >= 0);
646
647 pthread_mutex_lock(socket->lock);
648 send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
649 usess->consumer, socket->fd);
650 pthread_mutex_unlock(socket->lock);
651 if (ret != LTTNG_OK) {
652 goto error;
653 }
654 }
655 }
656
657 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
658 && ksess->consumer->enabled) {
659 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
660 socket, node.node) {
661 /* Code flow error */
662 assert(socket->fd >= 0);
663
664 pthread_mutex_lock(socket->lock);
665 send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
666 ksess->consumer, socket->fd);
667 pthread_mutex_unlock(socket->lock);
668 if (ret != LTTNG_OK) {
669 goto error;
670 }
671 }
672 }
673
674 error:
675 return ret;
676 }
677
678 /*
679 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
680 */
681 int cmd_disable_channel(struct ltt_session *session, int domain,
682 char *channel_name)
683 {
684 int ret;
685 struct ltt_ust_session *usess;
686
687 usess = session->ust_session;
688
689 switch (domain) {
690 case LTTNG_DOMAIN_KERNEL:
691 {
692 ret = channel_kernel_disable(session->kernel_session,
693 channel_name);
694 if (ret != LTTNG_OK) {
695 goto error;
696 }
697
698 kernel_wait_quiescent(kernel_tracer_fd);
699 break;
700 }
701 case LTTNG_DOMAIN_UST:
702 {
703 struct ltt_ust_channel *uchan;
704 struct lttng_ht *chan_ht;
705
706 chan_ht = usess->domain_global.channels;
707
708 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
709 if (uchan == NULL) {
710 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
711 goto error;
712 }
713
714 ret = channel_ust_disable(usess, domain, uchan);
715 if (ret != LTTNG_OK) {
716 goto error;
717 }
718 break;
719 }
720 #if 0
721 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
722 case LTTNG_DOMAIN_UST_EXEC_NAME:
723 case LTTNG_DOMAIN_UST_PID:
724 #endif
725 default:
726 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
727 goto error;
728 }
729
730 ret = LTTNG_OK;
731
732 error:
733 return ret;
734 }
735
736 /*
737 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
738 *
739 * The wpipe arguments is used as a notifier for the kernel thread.
740 */
741 int cmd_enable_channel(struct ltt_session *session,
742 int domain, struct lttng_channel *attr, int wpipe)
743 {
744 int ret;
745 struct ltt_ust_session *usess = session->ust_session;
746 struct lttng_ht *chan_ht;
747
748 assert(session);
749 assert(attr);
750
751 DBG("Enabling channel %s for session %s", attr->name, session->name);
752
753 switch (domain) {
754 case LTTNG_DOMAIN_KERNEL:
755 {
756 struct ltt_kernel_channel *kchan;
757
758 /* Mandatory for a kernel channel. */
759 assert(wpipe > 0);
760
761 kchan = trace_kernel_get_channel_by_name(attr->name,
762 session->kernel_session);
763 if (kchan == NULL) {
764 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
765 } else {
766 ret = channel_kernel_enable(session->kernel_session, kchan);
767 }
768
769 if (ret != LTTNG_OK) {
770 goto error;
771 }
772
773 kernel_wait_quiescent(kernel_tracer_fd);
774 break;
775 }
776 case LTTNG_DOMAIN_UST:
777 {
778 struct ltt_ust_channel *uchan;
779
780 chan_ht = usess->domain_global.channels;
781
782 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
783 if (uchan == NULL) {
784 ret = channel_ust_create(usess, domain, attr);
785 } else {
786 ret = channel_ust_enable(usess, domain, uchan);
787 }
788 break;
789 }
790 #if 0
791 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
792 case LTTNG_DOMAIN_UST_EXEC_NAME:
793 case LTTNG_DOMAIN_UST_PID:
794 #endif
795 default:
796 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
797 goto error;
798 }
799
800 error:
801 return ret;
802 }
803
804
805 /*
806 * Command LTTNG_DISABLE_EVENT processed by the client thread.
807 */
808 int cmd_disable_event(struct ltt_session *session, int domain,
809 char *channel_name, char *event_name)
810 {
811 int ret;
812
813 switch (domain) {
814 case LTTNG_DOMAIN_KERNEL:
815 {
816 struct ltt_kernel_channel *kchan;
817 struct ltt_kernel_session *ksess;
818
819 ksess = session->kernel_session;
820
821 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
822 if (kchan == NULL) {
823 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
824 goto error;
825 }
826
827 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
828 if (ret != LTTNG_OK) {
829 goto error;
830 }
831
832 kernel_wait_quiescent(kernel_tracer_fd);
833 break;
834 }
835 case LTTNG_DOMAIN_UST:
836 {
837 struct ltt_ust_channel *uchan;
838 struct ltt_ust_session *usess;
839
840 usess = session->ust_session;
841
842 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
843 channel_name);
844 if (uchan == NULL) {
845 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
846 goto error;
847 }
848
849 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
850 if (ret != LTTNG_OK) {
851 goto error;
852 }
853
854 DBG3("Disable UST event %s in channel %s completed", event_name,
855 channel_name);
856 break;
857 }
858 #if 0
859 case LTTNG_DOMAIN_UST_EXEC_NAME:
860 case LTTNG_DOMAIN_UST_PID:
861 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
862 #endif
863 default:
864 ret = LTTNG_ERR_UND;
865 goto error;
866 }
867
868 ret = LTTNG_OK;
869
870 error:
871 return ret;
872 }
873
874 /*
875 * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
876 */
877 int cmd_disable_event_all(struct ltt_session *session, int domain,
878 char *channel_name)
879 {
880 int ret;
881
882 switch (domain) {
883 case LTTNG_DOMAIN_KERNEL:
884 {
885 struct ltt_kernel_session *ksess;
886 struct ltt_kernel_channel *kchan;
887
888 ksess = session->kernel_session;
889
890 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
891 if (kchan == NULL) {
892 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
893 goto error;
894 }
895
896 ret = event_kernel_disable_all(ksess, kchan);
897 if (ret != LTTNG_OK) {
898 goto error;
899 }
900
901 kernel_wait_quiescent(kernel_tracer_fd);
902 break;
903 }
904 case LTTNG_DOMAIN_UST:
905 {
906 struct ltt_ust_session *usess;
907 struct ltt_ust_channel *uchan;
908
909 usess = session->ust_session;
910
911 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
912 channel_name);
913 if (uchan == NULL) {
914 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
915 goto error;
916 }
917
918 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
919 if (ret != 0) {
920 goto error;
921 }
922
923 DBG3("Disable all UST events in channel %s completed", channel_name);
924
925 break;
926 }
927 #if 0
928 case LTTNG_DOMAIN_UST_EXEC_NAME:
929 case LTTNG_DOMAIN_UST_PID:
930 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
931 #endif
932 default:
933 ret = LTTNG_ERR_UND;
934 goto error;
935 }
936
937 ret = LTTNG_OK;
938
939 error:
940 return ret;
941 }
942
943 /*
944 * Command LTTNG_ADD_CONTEXT processed by the client thread.
945 */
946 int cmd_add_context(struct ltt_session *session, int domain,
947 char *channel_name, char *event_name, struct lttng_event_context *ctx)
948 {
949 int ret;
950
951 switch (domain) {
952 case LTTNG_DOMAIN_KERNEL:
953 /* Add kernel context to kernel tracer */
954 ret = context_kernel_add(session->kernel_session, ctx,
955 event_name, channel_name);
956 if (ret != LTTNG_OK) {
957 goto error;
958 }
959 break;
960 case LTTNG_DOMAIN_UST:
961 {
962 struct ltt_ust_session *usess = session->ust_session;
963
964 assert(usess);
965
966 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
967 if (ret != LTTNG_OK) {
968 goto error;
969 }
970 break;
971 }
972 #if 0
973 case LTTNG_DOMAIN_UST_EXEC_NAME:
974 case LTTNG_DOMAIN_UST_PID:
975 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
976 #endif
977 default:
978 ret = LTTNG_ERR_UND;
979 goto error;
980 }
981
982 ret = LTTNG_OK;
983
984 error:
985 return ret;
986 }
987
988 /*
989 * Command LTTNG_SET_FILTER processed by the client thread.
990 */
991 int cmd_set_filter(struct ltt_session *session, int domain,
992 char *channel_name, char *event_name,
993 struct lttng_filter_bytecode *bytecode)
994 {
995 int ret;
996
997 switch (domain) {
998 case LTTNG_DOMAIN_KERNEL:
999 ret = LTTNG_ERR_FATAL;
1000 break;
1001 case LTTNG_DOMAIN_UST:
1002 {
1003 struct ltt_ust_session *usess = session->ust_session;
1004
1005 ret = filter_ust_set(usess, domain, bytecode, event_name, channel_name);
1006 if (ret != LTTNG_OK) {
1007 goto error;
1008 }
1009 break;
1010 }
1011 #if 0
1012 case LTTNG_DOMAIN_UST_EXEC_NAME:
1013 case LTTNG_DOMAIN_UST_PID:
1014 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1015 #endif
1016 default:
1017 ret = LTTNG_ERR_UND;
1018 goto error;
1019 }
1020
1021 ret = LTTNG_OK;
1022
1023 error:
1024 return ret;
1025
1026 }
1027
1028
1029 /*
1030 * Command LTTNG_ENABLE_EVENT processed by the client thread.
1031 */
1032 int cmd_enable_event(struct ltt_session *session, int domain,
1033 char *channel_name, struct lttng_event *event, int wpipe)
1034 {
1035 int ret;
1036 struct lttng_channel *attr;
1037
1038 assert(session);
1039 assert(event);
1040 assert(channel_name);
1041
1042 switch (domain) {
1043 case LTTNG_DOMAIN_KERNEL:
1044 {
1045 struct ltt_kernel_channel *kchan;
1046
1047 kchan = trace_kernel_get_channel_by_name(channel_name,
1048 session->kernel_session);
1049 if (kchan == NULL) {
1050 attr = channel_new_default_attr(domain);
1051 if (attr == NULL) {
1052 ret = LTTNG_ERR_FATAL;
1053 goto error;
1054 }
1055 strncpy(attr->name, channel_name, sizeof(attr->name));
1056
1057 ret = cmd_enable_channel(session, domain, attr, wpipe);
1058 if (ret != LTTNG_OK) {
1059 free(attr);
1060 goto error;
1061 }
1062 free(attr);
1063 }
1064
1065 /* Get the newly created kernel channel pointer */
1066 kchan = trace_kernel_get_channel_by_name(channel_name,
1067 session->kernel_session);
1068 if (kchan == NULL) {
1069 /* This sould not happen... */
1070 ret = LTTNG_ERR_FATAL;
1071 goto error;
1072 }
1073
1074 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1075 event);
1076 if (ret != LTTNG_OK) {
1077 goto error;
1078 }
1079
1080 kernel_wait_quiescent(kernel_tracer_fd);
1081 break;
1082 }
1083 case LTTNG_DOMAIN_UST:
1084 {
1085 struct ltt_ust_channel *uchan;
1086 struct ltt_ust_session *usess = session->ust_session;
1087
1088 assert(usess);
1089
1090 /* Get channel from global UST domain */
1091 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1092 channel_name);
1093 if (uchan == NULL) {
1094 /* Create default channel */
1095 attr = channel_new_default_attr(domain);
1096 if (attr == NULL) {
1097 ret = LTTNG_ERR_FATAL;
1098 goto error;
1099 }
1100 strncpy(attr->name, channel_name, sizeof(attr->name));
1101
1102 ret = cmd_enable_channel(session, domain, attr, wpipe);
1103 if (ret != LTTNG_OK) {
1104 free(attr);
1105 goto error;
1106 }
1107 free(attr);
1108
1109 /* Get the newly created channel reference back */
1110 uchan = trace_ust_find_channel_by_name(
1111 usess->domain_global.channels, channel_name);
1112 assert(uchan);
1113 }
1114
1115 /* At this point, the session and channel exist on the tracer */
1116 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
1117 if (ret != LTTNG_OK) {
1118 goto error;
1119 }
1120 break;
1121 }
1122 #if 0
1123 case LTTNG_DOMAIN_UST_EXEC_NAME:
1124 case LTTNG_DOMAIN_UST_PID:
1125 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1126 #endif
1127 default:
1128 ret = LTTNG_ERR_UND;
1129 goto error;
1130 }
1131
1132 ret = LTTNG_OK;
1133
1134 error:
1135 return ret;
1136 }
1137
1138 /*
1139 * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1140 */
1141 int cmd_enable_event_all(struct ltt_session *session, int domain,
1142 char *channel_name, int event_type, int wpipe)
1143 {
1144 int ret;
1145 struct lttng_channel *attr;
1146
1147 assert(session);
1148 assert(channel_name);
1149
1150 switch (domain) {
1151 case LTTNG_DOMAIN_KERNEL:
1152 {
1153 struct ltt_kernel_channel *kchan;
1154
1155 assert(session->kernel_session);
1156
1157 kchan = trace_kernel_get_channel_by_name(channel_name,
1158 session->kernel_session);
1159 if (kchan == NULL) {
1160 /* Create default channel */
1161 attr = channel_new_default_attr(domain);
1162 if (attr == NULL) {
1163 ret = LTTNG_ERR_FATAL;
1164 goto error;
1165 }
1166 strncpy(attr->name, channel_name, sizeof(attr->name));
1167
1168 ret = cmd_enable_channel(session, domain, attr, wpipe);
1169 if (ret != LTTNG_OK) {
1170 free(attr);
1171 goto error;
1172 }
1173 free(attr);
1174
1175 /* Get the newly created kernel channel pointer */
1176 kchan = trace_kernel_get_channel_by_name(channel_name,
1177 session->kernel_session);
1178 assert(kchan);
1179 }
1180
1181 switch (event_type) {
1182 case LTTNG_EVENT_SYSCALL:
1183 ret = event_kernel_enable_all_syscalls(session->kernel_session,
1184 kchan, kernel_tracer_fd);
1185 break;
1186 case LTTNG_EVENT_TRACEPOINT:
1187 /*
1188 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1189 * events already registered to the channel.
1190 */
1191 ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1192 kchan, kernel_tracer_fd);
1193 break;
1194 case LTTNG_EVENT_ALL:
1195 /* Enable syscalls and tracepoints */
1196 ret = event_kernel_enable_all(session->kernel_session,
1197 kchan, kernel_tracer_fd);
1198 break;
1199 default:
1200 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1201 goto error;
1202 }
1203
1204 /* Manage return value */
1205 if (ret != LTTNG_OK) {
1206 goto error;
1207 }
1208
1209 kernel_wait_quiescent(kernel_tracer_fd);
1210 break;
1211 }
1212 case LTTNG_DOMAIN_UST:
1213 {
1214 struct ltt_ust_channel *uchan;
1215 struct ltt_ust_session *usess = session->ust_session;
1216
1217 assert(usess);
1218
1219 /* Get channel from global UST domain */
1220 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1221 channel_name);
1222 if (uchan == NULL) {
1223 /* Create default channel */
1224 attr = channel_new_default_attr(domain);
1225 if (attr == NULL) {
1226 ret = LTTNG_ERR_FATAL;
1227 goto error;
1228 }
1229 strncpy(attr->name, channel_name, sizeof(attr->name));
1230
1231 ret = cmd_enable_channel(session, domain, attr, wpipe);
1232 if (ret != LTTNG_OK) {
1233 free(attr);
1234 goto error;
1235 }
1236 free(attr);
1237
1238 /* Get the newly created channel reference back */
1239 uchan = trace_ust_find_channel_by_name(
1240 usess->domain_global.channels, channel_name);
1241 assert(uchan);
1242 }
1243
1244 /* At this point, the session and channel exist on the tracer */
1245
1246 switch (event_type) {
1247 case LTTNG_EVENT_ALL:
1248 case LTTNG_EVENT_TRACEPOINT:
1249 ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
1250 if (ret != LTTNG_OK) {
1251 goto error;
1252 }
1253 break;
1254 default:
1255 ret = LTTNG_ERR_UST_ENABLE_FAIL;
1256 goto error;
1257 }
1258
1259 /* Manage return value */
1260 if (ret != LTTNG_OK) {
1261 goto error;
1262 }
1263
1264 break;
1265 }
1266 #if 0
1267 case LTTNG_DOMAIN_UST_EXEC_NAME:
1268 case LTTNG_DOMAIN_UST_PID:
1269 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1270 #endif
1271 default:
1272 ret = LTTNG_ERR_UND;
1273 goto error;
1274 }
1275
1276 ret = LTTNG_OK;
1277
1278 error:
1279 return ret;
1280 }
1281
1282
1283 /*
1284 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1285 */
1286 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1287 {
1288 int ret;
1289 ssize_t nb_events = 0;
1290
1291 switch (domain) {
1292 case LTTNG_DOMAIN_KERNEL:
1293 nb_events = kernel_list_events(kernel_tracer_fd, events);
1294 if (nb_events < 0) {
1295 ret = LTTNG_ERR_KERN_LIST_FAIL;
1296 goto error;
1297 }
1298 break;
1299 case LTTNG_DOMAIN_UST:
1300 nb_events = ust_app_list_events(events);
1301 if (nb_events < 0) {
1302 ret = LTTNG_ERR_UST_LIST_FAIL;
1303 goto error;
1304 }
1305 break;
1306 default:
1307 ret = LTTNG_ERR_UND;
1308 goto error;
1309 }
1310
1311 return nb_events;
1312
1313 error:
1314 /* Return negative value to differentiate return code */
1315 return -ret;
1316 }
1317
1318 /*
1319 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1320 */
1321 ssize_t cmd_list_tracepoint_fields(int domain,
1322 struct lttng_event_field **fields)
1323 {
1324 int ret;
1325 ssize_t nb_fields = 0;
1326
1327 switch (domain) {
1328 case LTTNG_DOMAIN_UST:
1329 nb_fields = ust_app_list_event_fields(fields);
1330 if (nb_fields < 0) {
1331 ret = LTTNG_ERR_UST_LIST_FAIL;
1332 goto error;
1333 }
1334 break;
1335 case LTTNG_DOMAIN_KERNEL:
1336 default: /* fall-through */
1337 ret = LTTNG_ERR_UND;
1338 goto error;
1339 }
1340
1341 return nb_fields;
1342
1343 error:
1344 /* Return negative value to differentiate return code */
1345 return -ret;
1346 }
1347
1348 /*
1349 * Command LTTNG_START_TRACE processed by the client thread.
1350 */
1351 int cmd_start_trace(struct ltt_session *session)
1352 {
1353 int ret;
1354 struct ltt_kernel_session *ksession;
1355 struct ltt_ust_session *usess;
1356 struct ltt_kernel_channel *kchan;
1357
1358 assert(session);
1359
1360 /* Ease our life a bit ;) */
1361 ksession = session->kernel_session;
1362 usess = session->ust_session;
1363
1364 if (session->enabled) {
1365 /* Already started. */
1366 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1367 goto error;
1368 }
1369
1370 session->enabled = 1;
1371
1372 ret = setup_relayd(session);
1373 if (ret != LTTNG_OK) {
1374 ERR("Error setting up relayd for session %s", session->name);
1375 goto error;
1376 }
1377
1378 /* Kernel tracing */
1379 if (ksession != NULL) {
1380 /* Open kernel metadata */
1381 if (ksession->metadata == NULL) {
1382 ret = kernel_open_metadata(ksession);
1383 if (ret < 0) {
1384 ret = LTTNG_ERR_KERN_META_FAIL;
1385 goto error;
1386 }
1387 }
1388
1389 /* Open kernel metadata stream */
1390 if (ksession->metadata_stream_fd < 0) {
1391 ret = kernel_open_metadata_stream(ksession);
1392 if (ret < 0) {
1393 ERR("Kernel create metadata stream failed");
1394 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1395 goto error;
1396 }
1397 }
1398
1399 /* For each channel */
1400 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1401 if (kchan->stream_count == 0) {
1402 ret = kernel_open_channel_stream(kchan);
1403 if (ret < 0) {
1404 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1405 goto error;
1406 }
1407 /* Update the stream global counter */
1408 ksession->stream_count_global += ret;
1409 }
1410 }
1411
1412 /* Setup kernel consumer socket and send fds to it */
1413 ret = init_kernel_tracing(ksession);
1414 if (ret < 0) {
1415 ret = LTTNG_ERR_KERN_START_FAIL;
1416 goto error;
1417 }
1418
1419 /* This start the kernel tracing */
1420 ret = kernel_start_session(ksession);
1421 if (ret < 0) {
1422 ret = LTTNG_ERR_KERN_START_FAIL;
1423 goto error;
1424 }
1425
1426 /* Quiescent wait after starting trace */
1427 kernel_wait_quiescent(kernel_tracer_fd);
1428 }
1429
1430 /* Flag session that trace should start automatically */
1431 if (usess) {
1432 usess->start_trace = 1;
1433
1434 ret = ust_app_start_trace_all(usess);
1435 if (ret < 0) {
1436 ret = LTTNG_ERR_UST_START_FAIL;
1437 goto error;
1438 }
1439 }
1440
1441 ret = LTTNG_OK;
1442
1443 error:
1444 return ret;
1445 }
1446
1447 /*
1448 * Command LTTNG_STOP_TRACE processed by the client thread.
1449 */
1450 int cmd_stop_trace(struct ltt_session *session)
1451 {
1452 int ret;
1453 struct ltt_kernel_channel *kchan;
1454 struct ltt_kernel_session *ksession;
1455 struct ltt_ust_session *usess;
1456
1457 assert(session);
1458
1459 /* Short cut */
1460 ksession = session->kernel_session;
1461 usess = session->ust_session;
1462
1463 if (!session->enabled) {
1464 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
1465 goto error;
1466 }
1467
1468 session->enabled = 0;
1469
1470 /* Kernel tracer */
1471 if (ksession) {
1472 DBG("Stop kernel tracing");
1473
1474 /* Flush metadata if exist */
1475 if (ksession->metadata_stream_fd >= 0) {
1476 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1477 if (ret < 0) {
1478 ERR("Kernel metadata flush failed");
1479 }
1480 }
1481
1482 /* Flush all buffers before stopping */
1483 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1484 ret = kernel_flush_buffer(kchan);
1485 if (ret < 0) {
1486 ERR("Kernel flush buffer error");
1487 }
1488 }
1489
1490 ret = kernel_stop_session(ksession);
1491 if (ret < 0) {
1492 ret = LTTNG_ERR_KERN_STOP_FAIL;
1493 goto error;
1494 }
1495
1496 kernel_wait_quiescent(kernel_tracer_fd);
1497 }
1498
1499 if (usess) {
1500 usess->start_trace = 0;
1501
1502 ret = ust_app_stop_trace_all(usess);
1503 if (ret < 0) {
1504 ret = LTTNG_ERR_UST_STOP_FAIL;
1505 goto error;
1506 }
1507 }
1508
1509 ret = LTTNG_OK;
1510
1511 error:
1512 return ret;
1513 }
1514
1515 /*
1516 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1517 */
1518 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1519 size_t nb_uri, struct lttng_uri *uris)
1520 {
1521 int ret, i;
1522 struct ltt_kernel_session *ksess = session->kernel_session;
1523 struct ltt_ust_session *usess = session->ust_session;
1524 struct consumer_output *consumer = NULL;
1525
1526 assert(session);
1527 assert(uris);
1528 assert(nb_uri > 0);
1529
1530 /* Can't enable consumer after session started. */
1531 if (session->enabled) {
1532 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1533 goto error;
1534 }
1535
1536 if (!session->start_consumer) {
1537 ret = LTTNG_ERR_NO_CONSUMER;
1538 goto error;
1539 }
1540
1541 /*
1542 * This case switch makes sure the domain session has a temporary consumer
1543 * so the URL can be set.
1544 */
1545 switch (domain) {
1546 case 0:
1547 /* Code flow error. A session MUST always have a consumer object */
1548 assert(session->consumer);
1549 /*
1550 * The URL will be added to the tracing session consumer instead of a
1551 * specific domain consumer.
1552 */
1553 consumer = session->consumer;
1554 break;
1555 case LTTNG_DOMAIN_KERNEL:
1556 /* Code flow error if we don't have a kernel session here. */
1557 assert(ksess);
1558
1559 /* Create consumer output if none exists */
1560 consumer = ksess->tmp_consumer;
1561 if (consumer == NULL) {
1562 consumer = consumer_copy_output(ksess->consumer);
1563 if (consumer == NULL) {
1564 ret = LTTNG_ERR_FATAL;
1565 goto error;
1566 }
1567 /* Trash the consumer subdir, we are about to set a new one. */
1568 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1569 ksess->tmp_consumer = consumer;
1570 }
1571
1572 break;
1573 case LTTNG_DOMAIN_UST:
1574 /* Code flow error if we don't have a kernel session here. */
1575 assert(usess);
1576
1577 /* Create consumer output if none exists */
1578 consumer = usess->tmp_consumer;
1579 if (consumer == NULL) {
1580 consumer = consumer_copy_output(usess->consumer);
1581 if (consumer == NULL) {
1582 ret = LTTNG_ERR_FATAL;
1583 goto error;
1584 }
1585 /* Trash the consumer subdir, we are about to set a new one. */
1586 memset(consumer->subdir, 0, sizeof(consumer->subdir));
1587 usess->tmp_consumer = consumer;
1588 }
1589
1590 break;
1591 }
1592
1593 for (i = 0; i < nb_uri; i++) {
1594 struct consumer_socket *socket;
1595 struct lttng_ht_iter iter;
1596
1597 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1598 if (ret < 0) {
1599 goto error;
1600 }
1601
1602 /*
1603 * Don't send relayd socket if URI is NOT remote or if the relayd
1604 * sockets for the session are already sent.
1605 */
1606 if (uris[i].dtype == LTTNG_DST_PATH ||
1607 consumer->dst.net.relayd_socks_sent) {
1608 continue;
1609 }
1610
1611 /* Try to send relayd URI to the consumer if exist. */
1612 rcu_read_lock();
1613 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1614 socket, node.node) {
1615
1616 /* A socket in the HT should never have a negative fd */
1617 assert(socket->fd >= 0);
1618
1619 pthread_mutex_lock(socket->lock);
1620 ret = send_consumer_relayd_socket(domain, session, &uris[i],
1621 consumer, socket->fd);
1622 pthread_mutex_unlock(socket->lock);
1623 if (ret != LTTNG_OK) {
1624 rcu_read_unlock();
1625 goto error;
1626 }
1627 }
1628 rcu_read_unlock();
1629 }
1630
1631 /* All good! */
1632 ret = LTTNG_OK;
1633
1634 error:
1635 return ret;
1636 }
1637
1638 /*
1639 * Command LTTNG_CREATE_SESSION processed by the client thread.
1640 */
1641 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1642 size_t nb_uri, lttng_sock_cred *creds)
1643 {
1644 int ret;
1645 char *path = NULL;
1646 struct ltt_session *session;
1647
1648 assert(name);
1649
1650 /*
1651 * Verify if the session already exist
1652 *
1653 * XXX: There is no need for the session lock list here since the caller
1654 * (process_client_msg) is holding it. We might want to change that so a
1655 * single command does not lock the entire session list.
1656 */
1657 session = session_find_by_name(name);
1658 if (session != NULL) {
1659 ret = LTTNG_ERR_EXIST_SESS;
1660 goto find_error;
1661 }
1662
1663 /* Create tracing session in the registry */
1664 ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1665 LTTNG_SOCK_GET_GID_CRED(creds));
1666 if (ret != LTTNG_OK) {
1667 goto session_error;
1668 }
1669
1670 /*
1671 * Get the newly created session pointer back
1672 *
1673 * XXX: There is no need for the session lock list here since the caller
1674 * (process_client_msg) is holding it. We might want to change that so a
1675 * single command does not lock the entire session list.
1676 */
1677 session = session_find_by_name(name);
1678 assert(session);
1679
1680 /* Create default consumer output for the session not yet created. */
1681 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1682 if (session->consumer == NULL) {
1683 ret = LTTNG_ERR_FATAL;
1684 goto consumer_error;
1685 }
1686
1687 /*
1688 * This means that the lttng_create_session call was called with the _path_
1689 * argument set to NULL.
1690 */
1691 if (uris == NULL) {
1692 /*
1693 * At this point, we'll skip the consumer URI setup and create a
1694 * session with a NULL path which will flag the session to NOT spawn a
1695 * consumer.
1696 */
1697 DBG("Create session %s with NO uri, skipping consumer setup", name);
1698 goto end;
1699 }
1700
1701 session->start_consumer = 1;
1702
1703 ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1704 if (ret != LTTNG_OK) {
1705 goto consumer_error;
1706 }
1707
1708 session->consumer->enabled = 1;
1709
1710 end:
1711 return LTTNG_OK;
1712
1713 consumer_error:
1714 session_destroy(session);
1715 session_error:
1716 find_error:
1717 return ret;
1718 }
1719
1720 /*
1721 * Command LTTNG_DESTROY_SESSION processed by the client thread.
1722 */
1723 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1724 {
1725 int ret;
1726 struct ltt_ust_session *usess;
1727 struct ltt_kernel_session *ksess;
1728
1729 /* Safety net */
1730 assert(session);
1731
1732 usess = session->ust_session;
1733 ksess = session->kernel_session;
1734
1735 /* Clean kernel session teardown */
1736 kernel_destroy_session(ksess);
1737
1738 /* UST session teardown */
1739 if (usess) {
1740 /* Close any relayd session */
1741 consumer_output_send_destroy_relayd(usess->consumer);
1742
1743 /* Destroy every UST application related to this session. */
1744 ret = ust_app_destroy_trace_all(usess);
1745 if (ret) {
1746 ERR("Error in ust_app_destroy_trace_all");
1747 }
1748
1749 /* Clean up the rest. */
1750 trace_ust_destroy_session(usess);
1751 }
1752
1753 /*
1754 * Must notify the kernel thread here to update it's poll set in order to
1755 * remove the channel(s)' fd just destroyed.
1756 */
1757 ret = notify_thread_pipe(wpipe);
1758 if (ret < 0) {
1759 PERROR("write kernel poll pipe");
1760 }
1761
1762 ret = session_destroy(session);
1763
1764 return ret;
1765 }
1766
1767 /*
1768 * Command LTTNG_CALIBRATE processed by the client thread.
1769 */
1770 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1771 {
1772 int ret;
1773
1774 switch (domain) {
1775 case LTTNG_DOMAIN_KERNEL:
1776 {
1777 struct lttng_kernel_calibrate kcalibrate;
1778
1779 kcalibrate.type = calibrate->type;
1780 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1781 if (ret < 0) {
1782 ret = LTTNG_ERR_KERN_ENABLE_FAIL;
1783 goto error;
1784 }
1785 break;
1786 }
1787 case LTTNG_DOMAIN_UST:
1788 {
1789 struct lttng_ust_calibrate ucalibrate;
1790
1791 ucalibrate.type = calibrate->type;
1792 ret = ust_app_calibrate_glb(&ucalibrate);
1793 if (ret < 0) {
1794 ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
1795 goto error;
1796 }
1797 break;
1798 }
1799 default:
1800 ret = LTTNG_ERR_UND;
1801 goto error;
1802 }
1803
1804 ret = LTTNG_OK;
1805
1806 error:
1807 return ret;
1808 }
1809
1810 /*
1811 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1812 */
1813 int cmd_register_consumer(struct ltt_session *session, int domain,
1814 const char *sock_path, struct consumer_data *cdata)
1815 {
1816 int ret, sock;
1817 struct consumer_socket *socket;
1818
1819 assert(session);
1820 assert(cdata);
1821 assert(sock_path);
1822
1823 switch (domain) {
1824 case LTTNG_DOMAIN_KERNEL:
1825 {
1826 struct ltt_kernel_session *ksess = session->kernel_session;
1827
1828 assert(ksess);
1829
1830 /* Can't register a consumer if there is already one */
1831 if (ksess->consumer_fds_sent != 0) {
1832 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1833 goto error;
1834 }
1835
1836 sock = lttcomm_connect_unix_sock(sock_path);
1837 if (sock < 0) {
1838 ret = LTTNG_ERR_CONNECT_FAIL;
1839 goto error;
1840 }
1841
1842 socket = consumer_allocate_socket(sock);
1843 if (socket == NULL) {
1844 ret = LTTNG_ERR_FATAL;
1845 close(sock);
1846 goto error;
1847 }
1848
1849 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1850 if (socket->lock == NULL) {
1851 PERROR("zmalloc pthread mutex");
1852 ret = LTTNG_ERR_FATAL;
1853 goto error;
1854 }
1855 pthread_mutex_init(socket->lock, NULL);
1856 socket->registered = 1;
1857
1858 rcu_read_lock();
1859 consumer_add_socket(socket, ksess->consumer);
1860 rcu_read_unlock();
1861
1862 pthread_mutex_lock(&cdata->pid_mutex);
1863 cdata->pid = -1;
1864 pthread_mutex_unlock(&cdata->pid_mutex);
1865
1866 break;
1867 }
1868 default:
1869 /* TODO: Userspace tracing */
1870 ret = LTTNG_ERR_UND;
1871 goto error;
1872 }
1873
1874 ret = LTTNG_OK;
1875
1876 error:
1877 return ret;
1878 }
1879
1880 /*
1881 * Command LTTNG_LIST_DOMAINS processed by the client thread.
1882 */
1883 ssize_t cmd_list_domains(struct ltt_session *session,
1884 struct lttng_domain **domains)
1885 {
1886 int ret, index = 0;
1887 ssize_t nb_dom = 0;
1888
1889 if (session->kernel_session != NULL) {
1890 DBG3("Listing domains found kernel domain");
1891 nb_dom++;
1892 }
1893
1894 if (session->ust_session != NULL) {
1895 DBG3("Listing domains found UST global domain");
1896 nb_dom++;
1897 }
1898
1899 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1900 if (*domains == NULL) {
1901 ret = LTTNG_ERR_FATAL;
1902 goto error;
1903 }
1904
1905 if (session->kernel_session != NULL) {
1906 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1907 index++;
1908 }
1909
1910 if (session->ust_session != NULL) {
1911 (*domains)[index].type = LTTNG_DOMAIN_UST;
1912 index++;
1913 }
1914
1915 return nb_dom;
1916
1917 error:
1918 /* Return negative value to differentiate return code */
1919 return -ret;
1920 }
1921
1922
1923 /*
1924 * Command LTTNG_LIST_CHANNELS processed by the client thread.
1925 */
1926 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1927 struct lttng_channel **channels)
1928 {
1929 int ret;
1930 ssize_t nb_chan = 0;
1931
1932 switch (domain) {
1933 case LTTNG_DOMAIN_KERNEL:
1934 if (session->kernel_session != NULL) {
1935 nb_chan = session->kernel_session->channel_count;
1936 }
1937 DBG3("Number of kernel channels %zd", nb_chan);
1938 if (nb_chan <= 0) {
1939 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1940 }
1941 break;
1942 case LTTNG_DOMAIN_UST:
1943 if (session->ust_session != NULL) {
1944 nb_chan = lttng_ht_get_count(
1945 session->ust_session->domain_global.channels);
1946 }
1947 DBG3("Number of UST global channels %zd", nb_chan);
1948 if (nb_chan <= 0) {
1949 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1950 }
1951 break;
1952 default:
1953 *channels = NULL;
1954 ret = LTTNG_ERR_UND;
1955 goto error;
1956 }
1957
1958 if (nb_chan > 0) {
1959 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
1960 if (*channels == NULL) {
1961 ret = LTTNG_ERR_FATAL;
1962 goto error;
1963 }
1964
1965 list_lttng_channels(domain, session, *channels);
1966 } else {
1967 *channels = NULL;
1968 /* Ret value was set in the domain switch case */
1969 goto error;
1970 }
1971
1972 return nb_chan;
1973
1974 error:
1975 /* Return negative value to differentiate return code */
1976 return -ret;
1977 }
1978
1979 /*
1980 * Command LTTNG_LIST_EVENTS processed by the client thread.
1981 */
1982 ssize_t cmd_list_events(int domain, struct ltt_session *session,
1983 char *channel_name, struct lttng_event **events)
1984 {
1985 int ret = 0;
1986 ssize_t nb_event = 0;
1987
1988 switch (domain) {
1989 case LTTNG_DOMAIN_KERNEL:
1990 if (session->kernel_session != NULL) {
1991 nb_event = list_lttng_kernel_events(channel_name,
1992 session->kernel_session, events);
1993 }
1994 break;
1995 case LTTNG_DOMAIN_UST:
1996 {
1997 if (session->ust_session != NULL) {
1998 nb_event = list_lttng_ust_global_events(channel_name,
1999 &session->ust_session->domain_global, events);
2000 }
2001 break;
2002 }
2003 default:
2004 ret = LTTNG_ERR_UND;
2005 goto error;
2006 }
2007
2008 return nb_event;
2009
2010 error:
2011 /* Return negative value to differentiate return code */
2012 return -ret;
2013 }
2014
2015 /*
2016 * Using the session list, filled a lttng_session array to send back to the
2017 * client for session listing.
2018 *
2019 * The session list lock MUST be acquired before calling this function. Use
2020 * session_lock_list() and session_unlock_list().
2021 */
2022 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2023 gid_t gid)
2024 {
2025 int ret;
2026 unsigned int i = 0;
2027 struct ltt_session *session;
2028 struct ltt_session_list *list = session_get_list();
2029
2030 DBG("Getting all available session for UID %d GID %d",
2031 uid, gid);
2032 /*
2033 * Iterate over session list and append data after the control struct in
2034 * the buffer.
2035 */
2036 cds_list_for_each_entry(session, &list->head, list) {
2037 /*
2038 * Only list the sessions the user can control.
2039 */
2040 if (!session_access_ok(session, uid, gid)) {
2041 continue;
2042 }
2043
2044 struct ltt_kernel_session *ksess = session->kernel_session;
2045 struct ltt_ust_session *usess = session->ust_session;
2046
2047 if (session->consumer->type == CONSUMER_DST_NET ||
2048 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2049 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2050 ret = build_network_session_path(sessions[i].path,
2051 sizeof(session[i].path), session);
2052 } else {
2053 ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2054 session->consumer->dst.trace_path);
2055 }
2056 if (ret < 0) {
2057 PERROR("snprintf session path");
2058 continue;
2059 }
2060
2061 strncpy(sessions[i].name, session->name, NAME_MAX);
2062 sessions[i].name[NAME_MAX - 1] = '\0';
2063 sessions[i].enabled = session->enabled;
2064 i++;
2065 }
2066 }
2067
2068 /*
2069 * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2070 */
2071 int cmd_disable_consumer(int domain, struct ltt_session *session)
2072 {
2073 int ret;
2074 struct ltt_kernel_session *ksess = session->kernel_session;
2075 struct ltt_ust_session *usess = session->ust_session;
2076 struct consumer_output *consumer;
2077
2078 assert(session);
2079
2080 if (session->enabled) {
2081 /* Can't disable consumer on an already started session */
2082 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2083 goto error;
2084 }
2085
2086 if (!session->start_consumer) {
2087 ret = LTTNG_ERR_NO_CONSUMER;
2088 goto error;
2089 }
2090
2091 switch (domain) {
2092 case 0:
2093 DBG("Disable tracing session %s consumer", session->name);
2094 consumer = session->consumer;
2095 break;
2096 case LTTNG_DOMAIN_KERNEL:
2097 /* Code flow error if we don't have a kernel session here. */
2098 assert(ksess);
2099
2100 DBG("Disabling kernel consumer");
2101 consumer = ksess->consumer;
2102
2103 break;
2104 case LTTNG_DOMAIN_UST:
2105 /* Code flow error if we don't have a UST session here. */
2106 assert(usess);
2107
2108 DBG("Disabling UST consumer");
2109 consumer = usess->consumer;
2110
2111 break;
2112 default:
2113 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
2114 goto error;
2115 }
2116
2117 if (consumer) {
2118 consumer->enabled = 0;
2119 /* Success at this point */
2120 ret = LTTNG_OK;
2121 } else {
2122 ret = LTTNG_ERR_NO_CONSUMER;
2123 }
2124
2125 error:
2126 return ret;
2127 }
2128
2129 /*
2130 * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2131 */
2132 int cmd_enable_consumer(int domain, struct ltt_session *session)
2133 {
2134 int ret;
2135 struct ltt_kernel_session *ksess = session->kernel_session;
2136 struct ltt_ust_session *usess = session->ust_session;
2137 struct consumer_output *consumer = NULL;
2138
2139 assert(session);
2140
2141 /* Can't enable consumer after session started. */
2142 if (session->enabled) {
2143 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2144 goto error;
2145 }
2146
2147 if (!session->start_consumer) {
2148 ret = LTTNG_ERR_NO_CONSUMER;
2149 goto error;
2150 }
2151
2152 switch (domain) {
2153 case 0:
2154 assert(session->consumer);
2155 consumer = session->consumer;
2156 break;
2157 case LTTNG_DOMAIN_KERNEL:
2158 /* Code flow error if we don't have a kernel session here. */
2159 assert(ksess);
2160
2161 /*
2162 * Check if we have already sent fds to the consumer. In that case,
2163 * the enable-consumer command can't be used because a start trace
2164 * had previously occured.
2165 */
2166 if (ksess->consumer_fds_sent) {
2167 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2168 goto error;
2169 }
2170
2171 consumer = ksess->tmp_consumer;
2172 if (consumer == NULL) {
2173 ret = LTTNG_OK;
2174 /* No temp. consumer output exists. Using the current one. */
2175 DBG3("No temporary consumer. Using default");
2176 consumer = ksess->consumer;
2177 goto error;
2178 }
2179
2180 switch (consumer->type) {
2181 case CONSUMER_DST_LOCAL:
2182 DBG2("Consumer output is local. Creating directory(ies)");
2183
2184 /* Create directory(ies) */
2185 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2186 S_IRWXU | S_IRWXG, session->uid, session->gid);
2187 if (ret < 0) {
2188 if (ret != -EEXIST) {
2189 ERR("Trace directory creation error");
2190 ret = LTTNG_ERR_FATAL;
2191 goto error;
2192 }
2193 }
2194 break;
2195 case CONSUMER_DST_NET:
2196 DBG2("Consumer output is network. Validating URIs");
2197 /* Validate if we have both control and data path set. */
2198 if (!consumer->dst.net.control_isset) {
2199 ret = LTTNG_ERR_URL_CTRL_MISS;
2200 goto error;
2201 }
2202
2203 if (!consumer->dst.net.data_isset) {
2204 ret = LTTNG_ERR_URL_DATA_MISS;
2205 goto error;
2206 }
2207
2208 /* Check established network session state */
2209 if (session->net_handle == 0) {
2210 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2211 ERR("Session network handle is not set on enable-consumer");
2212 goto error;
2213 }
2214
2215 break;
2216 }
2217
2218 /* Append default kernel trace dir to subdir */
2219 strncat(ksess->consumer->subdir, DEFAULT_KERNEL_TRACE_DIR,
2220 sizeof(ksess->consumer->subdir) -
2221 strlen(ksess->consumer->subdir) - 1);
2222
2223 /*
2224 * @session-lock
2225 * This is race free for now since the session lock is acquired before
2226 * ending up in this function. No other threads can access this kernel
2227 * session without this lock hence freeing the consumer output object
2228 * is valid.
2229 */
2230 rcu_read_lock();
2231 consumer_destroy_output(ksess->consumer);
2232 rcu_read_unlock();
2233 ksess->consumer = consumer;
2234 ksess->tmp_consumer = NULL;
2235
2236 break;
2237 case LTTNG_DOMAIN_UST:
2238 /* Code flow error if we don't have a UST session here. */
2239 assert(usess);
2240
2241 /*
2242 * Check if we have already sent fds to the consumer. In that case,
2243 * the enable-consumer command can't be used because a start trace
2244 * had previously occured.
2245 */
2246 if (usess->start_trace) {
2247 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2248 goto error;
2249 }
2250
2251 consumer = usess->tmp_consumer;
2252 if (consumer == NULL) {
2253 ret = LTTNG_OK;
2254 /* No temp. consumer output exists. Using the current one. */
2255 DBG3("No temporary consumer. Using default");
2256 consumer = usess->consumer;
2257 goto error;
2258 }
2259
2260 switch (consumer->type) {
2261 case CONSUMER_DST_LOCAL:
2262 DBG2("Consumer output is local. Creating directory(ies)");
2263
2264 /* Create directory(ies) */
2265 ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2266 S_IRWXU | S_IRWXG, session->uid, session->gid);
2267 if (ret < 0) {
2268 if (ret != -EEXIST) {
2269 ERR("Trace directory creation error");
2270 ret = LTTNG_ERR_FATAL;
2271 goto error;
2272 }
2273 }
2274 break;
2275 case CONSUMER_DST_NET:
2276 DBG2("Consumer output is network. Validating URIs");
2277 /* Validate if we have both control and data path set. */
2278 if (!consumer->dst.net.control_isset) {
2279 ret = LTTNG_ERR_URL_CTRL_MISS;
2280 goto error;
2281 }
2282
2283 if (!consumer->dst.net.data_isset) {
2284 ret = LTTNG_ERR_URL_DATA_MISS;
2285 goto error;
2286 }
2287
2288 /* Check established network session state */
2289 if (session->net_handle == 0) {
2290 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2291 DBG2("Session network handle is not set on enable-consumer");
2292 goto error;
2293 }
2294
2295 if (consumer->net_seq_index == -1) {
2296 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
2297 DBG2("Network index is not set on the consumer");
2298 goto error;
2299 }
2300
2301 break;
2302 }
2303
2304 /* Append default kernel trace dir to subdir */
2305 strncat(usess->consumer->subdir, DEFAULT_UST_TRACE_DIR,
2306 sizeof(usess->consumer->subdir) -
2307 strlen(usess->consumer->subdir) - 1);
2308
2309 /*
2310 * @session-lock
2311 * This is race free for now since the session lock is acquired before
2312 * ending up in this function. No other threads can access this kernel
2313 * session without this lock hence freeing the consumer output object
2314 * is valid.
2315 */
2316 rcu_read_lock();
2317 consumer_destroy_output(usess->consumer);
2318 rcu_read_unlock();
2319 usess->consumer = consumer;
2320 usess->tmp_consumer = NULL;
2321
2322 break;
2323 }
2324
2325 /* Enable it */
2326 if (consumer) {
2327 consumer->enabled = 1;
2328 /* Success at this point */
2329 ret = LTTNG_OK;
2330 } else {
2331 /* Should not really happend... */
2332 ret = LTTNG_ERR_NO_CONSUMER;
2333 }
2334
2335 error:
2336 return ret;
2337 }
2338
2339 /*
2340 * Init command subsystem.
2341 */
2342 void cmd_init(void)
2343 {
2344 /*
2345 * Set network sequence index to 1 for streams to match a relayd socket on
2346 * the consumer side.
2347 */
2348 uatomic_set(&relayd_net_seq_idx, 1);
2349
2350 DBG("Command subsystem initialized");
2351 }
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