1ac133f3606d68d3114bb6405f103d89f30851ea
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25
26 #include <common/defaults.h>
27 #include <common/common.h>
28 #include <common/sessiond-comm/sessiond-comm.h>
29 #include <common/relayd/relayd.h>
30 #include <common/utils.h>
31 #include <common/compat/string.h>
32 #include <common/kernel-ctl/kernel-ctl.h>
33 #include <common/dynamic-buffer.h>
34 #include <common/buffer-view.h>
35 #include <lttng/trigger/trigger-internal.h>
36 #include <lttng/condition/condition.h>
37 #include <lttng/action/action.h>
38 #include <lttng/channel.h>
39 #include <lttng/channel-internal.h>
40 #include <lttng/rotate-internal.h>
41 #include <lttng/location-internal.h>
42 #include <lttng/userspace-probe-internal.h>
43 #include <common/string-utils/string-utils.h>
44
45 #include "channel.h"
46 #include "consumer.h"
47 #include "event.h"
48 #include "health-sessiond.h"
49 #include "kernel.h"
50 #include "kernel-consumer.h"
51 #include "lttng-sessiond.h"
52 #include "utils.h"
53 #include "lttng-syscall.h"
54 #include "agent.h"
55 #include "buffer-registry.h"
56 #include "notification-thread.h"
57 #include "notification-thread-commands.h"
58 #include "rotate.h"
59 #include "rotation-thread.h"
60 #include "timer.h"
61 #include "agent-thread.h"
62
63 #include "cmd.h"
64
65 /* Sleep for 100ms between each check for the shm path's deletion. */
66 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
67
68 static enum lttng_error_code wait_on_path(void *path);
69
70 /*
71 * Command completion handler that is used by the destroy command
72 * when a session that has a non-default shm_path is being destroyed.
73 *
74 * See comment in cmd_destroy_session() for the rationale.
75 */
76 static struct destroy_completion_handler {
77 struct cmd_completion_handler handler;
78 char shm_path[member_sizeof(struct ltt_session, shm_path)];
79 } destroy_completion_handler = {
80 .handler = {
81 .run = wait_on_path,
82 .data = destroy_completion_handler.shm_path
83 },
84 .shm_path = { 0 },
85 };
86
87 static struct cmd_completion_handler *current_completion_handler;
88
89 /*
90 * Used to keep a unique index for each relayd socket created where this value
91 * is associated with streams on the consumer so it can match the right relayd
92 * to send to. It must be accessed with the relayd_net_seq_idx_lock
93 * held.
94 */
95 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
96 static uint64_t relayd_net_seq_idx;
97
98 static int validate_ust_event_name(const char *);
99 static int cmd_enable_event_internal(struct ltt_session *session,
100 struct lttng_domain *domain,
101 char *channel_name, struct lttng_event *event,
102 char *filter_expression,
103 struct lttng_filter_bytecode *filter,
104 struct lttng_event_exclusion *exclusion,
105 int wpipe);
106
107 /*
108 * Create a session path used by list_lttng_sessions for the case that the
109 * session consumer is on the network.
110 */
111 static int build_network_session_path(char *dst, size_t size,
112 struct ltt_session *session)
113 {
114 int ret, kdata_port, udata_port;
115 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
116 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
117
118 assert(session);
119 assert(dst);
120
121 memset(tmp_urls, 0, sizeof(tmp_urls));
122 memset(tmp_uurl, 0, sizeof(tmp_uurl));
123
124 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
125
126 if (session->kernel_session && session->kernel_session->consumer) {
127 kuri = &session->kernel_session->consumer->dst.net.control;
128 kdata_port = session->kernel_session->consumer->dst.net.data.port;
129 }
130
131 if (session->ust_session && session->ust_session->consumer) {
132 uuri = &session->ust_session->consumer->dst.net.control;
133 udata_port = session->ust_session->consumer->dst.net.data.port;
134 }
135
136 if (uuri == NULL && kuri == NULL) {
137 uri = &session->consumer->dst.net.control;
138 kdata_port = session->consumer->dst.net.data.port;
139 } else if (kuri && uuri) {
140 ret = uri_compare(kuri, uuri);
141 if (ret) {
142 /* Not Equal */
143 uri = kuri;
144 /* Build uuri URL string */
145 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
146 if (ret < 0) {
147 goto error;
148 }
149 } else {
150 uri = kuri;
151 }
152 } else if (kuri && uuri == NULL) {
153 uri = kuri;
154 } else if (uuri && kuri == NULL) {
155 uri = uuri;
156 }
157
158 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
159 if (ret < 0) {
160 goto error;
161 }
162
163 /*
164 * Do we have a UST url set. If yes, this means we have both kernel and UST
165 * to print.
166 */
167 if (*tmp_uurl != '\0') {
168 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
169 tmp_urls, kdata_port, tmp_uurl, udata_port);
170 } else {
171 int dport;
172 if (kuri || (!kuri && !uuri)) {
173 dport = kdata_port;
174 } else {
175 /* No kernel URI, use the UST port. */
176 dport = udata_port;
177 }
178 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
179 }
180
181 error:
182 return ret;
183 }
184
185 /*
186 * Get run-time attributes if the session has been started (discarded events,
187 * lost packets).
188 */
189 static int get_kernel_runtime_stats(struct ltt_session *session,
190 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
191 uint64_t *lost_packets)
192 {
193 int ret;
194
195 if (!session->has_been_started) {
196 ret = 0;
197 *discarded_events = 0;
198 *lost_packets = 0;
199 goto end;
200 }
201
202 ret = consumer_get_discarded_events(session->id, kchan->key,
203 session->kernel_session->consumer,
204 discarded_events);
205 if (ret < 0) {
206 goto end;
207 }
208
209 ret = consumer_get_lost_packets(session->id, kchan->key,
210 session->kernel_session->consumer,
211 lost_packets);
212 if (ret < 0) {
213 goto end;
214 }
215
216 end:
217 return ret;
218 }
219
220 /*
221 * Get run-time attributes if the session has been started (discarded events,
222 * lost packets).
223 */
224 static int get_ust_runtime_stats(struct ltt_session *session,
225 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
226 uint64_t *lost_packets)
227 {
228 int ret;
229 struct ltt_ust_session *usess;
230
231 if (!discarded_events || !lost_packets) {
232 ret = -1;
233 goto end;
234 }
235
236 usess = session->ust_session;
237 assert(discarded_events);
238 assert(lost_packets);
239
240 if (!usess || !session->has_been_started) {
241 *discarded_events = 0;
242 *lost_packets = 0;
243 ret = 0;
244 goto end;
245 }
246
247 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
248 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
249 &usess->buffer_reg_uid_list,
250 usess->consumer, uchan->id,
251 uchan->attr.overwrite,
252 discarded_events,
253 lost_packets);
254 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
255 ret = ust_app_pid_get_channel_runtime_stats(usess,
256 uchan, usess->consumer,
257 uchan->attr.overwrite,
258 discarded_events,
259 lost_packets);
260 if (ret < 0) {
261 goto end;
262 }
263 *discarded_events += uchan->per_pid_closed_app_discarded;
264 *lost_packets += uchan->per_pid_closed_app_lost;
265 } else {
266 ERR("Unsupported buffer type");
267 assert(0);
268 ret = -1;
269 goto end;
270 }
271
272 end:
273 return ret;
274 }
275
276 /*
277 * Fill lttng_channel array of all channels.
278 */
279 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
280 struct ltt_session *session, struct lttng_channel *channels,
281 struct lttng_channel_extended *chan_exts)
282 {
283 int i = 0, ret = 0;
284 struct ltt_kernel_channel *kchan;
285
286 DBG("Listing channels for session %s", session->name);
287
288 switch (domain) {
289 case LTTNG_DOMAIN_KERNEL:
290 /* Kernel channels */
291 if (session->kernel_session != NULL) {
292 cds_list_for_each_entry(kchan,
293 &session->kernel_session->channel_list.head, list) {
294 uint64_t discarded_events, lost_packets;
295 struct lttng_channel_extended *extended;
296
297 extended = (struct lttng_channel_extended *)
298 kchan->channel->attr.extended.ptr;
299
300 ret = get_kernel_runtime_stats(session, kchan,
301 &discarded_events, &lost_packets);
302 if (ret < 0) {
303 goto end;
304 }
305 /* Copy lttng_channel struct to array */
306 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
307 channels[i].enabled = kchan->enabled;
308 chan_exts[i].discarded_events =
309 discarded_events;
310 chan_exts[i].lost_packets = lost_packets;
311 chan_exts[i].monitor_timer_interval =
312 extended->monitor_timer_interval;
313 chan_exts[i].blocking_timeout = 0;
314 i++;
315 }
316 }
317 break;
318 case LTTNG_DOMAIN_UST:
319 {
320 struct lttng_ht_iter iter;
321 struct ltt_ust_channel *uchan;
322
323 rcu_read_lock();
324 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
325 &iter.iter, uchan, node.node) {
326 uint64_t discarded_events = 0, lost_packets = 0;
327
328 if (lttng_strncpy(channels[i].name, uchan->name,
329 LTTNG_SYMBOL_NAME_LEN)) {
330 break;
331 }
332 channels[i].attr.overwrite = uchan->attr.overwrite;
333 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
334 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
335 channels[i].attr.switch_timer_interval =
336 uchan->attr.switch_timer_interval;
337 channels[i].attr.read_timer_interval =
338 uchan->attr.read_timer_interval;
339 channels[i].enabled = uchan->enabled;
340 channels[i].attr.tracefile_size = uchan->tracefile_size;
341 channels[i].attr.tracefile_count = uchan->tracefile_count;
342
343 /*
344 * Map enum lttng_ust_output to enum lttng_event_output.
345 */
346 switch (uchan->attr.output) {
347 case LTTNG_UST_MMAP:
348 channels[i].attr.output = LTTNG_EVENT_MMAP;
349 break;
350 default:
351 /*
352 * LTTNG_UST_MMAP is the only supported UST
353 * output mode.
354 */
355 assert(0);
356 break;
357 }
358
359 chan_exts[i].monitor_timer_interval =
360 uchan->monitor_timer_interval;
361 chan_exts[i].blocking_timeout =
362 uchan->attr.u.s.blocking_timeout;
363
364 ret = get_ust_runtime_stats(session, uchan,
365 &discarded_events, &lost_packets);
366 if (ret < 0) {
367 break;
368 }
369 chan_exts[i].discarded_events = discarded_events;
370 chan_exts[i].lost_packets = lost_packets;
371 i++;
372 }
373 rcu_read_unlock();
374 break;
375 }
376 default:
377 break;
378 }
379
380 end:
381 if (ret < 0) {
382 return -LTTNG_ERR_FATAL;
383 } else {
384 return LTTNG_OK;
385 }
386 }
387
388 static int increment_extended_len(const char *filter_expression,
389 struct lttng_event_exclusion *exclusion,
390 const struct lttng_userspace_probe_location *probe_location,
391 size_t *extended_len)
392 {
393 int ret = 0;
394
395 *extended_len += sizeof(struct lttcomm_event_extended_header);
396
397 if (filter_expression) {
398 *extended_len += strlen(filter_expression) + 1;
399 }
400
401 if (exclusion) {
402 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
403 }
404
405 if (probe_location) {
406 ret = lttng_userspace_probe_location_serialize(probe_location,
407 NULL, NULL);
408 if (ret < 0) {
409 goto end;
410 }
411 *extended_len += ret;
412 }
413 ret = 0;
414 end:
415 return ret;
416 }
417
418 static int append_extended_info(const char *filter_expression,
419 struct lttng_event_exclusion *exclusion,
420 struct lttng_userspace_probe_location *probe_location,
421 void **extended_at)
422 {
423 int ret = 0;
424 size_t filter_len = 0;
425 size_t nb_exclusions = 0;
426 size_t userspace_probe_location_len = 0;
427 struct lttng_dynamic_buffer location_buffer;
428 struct lttcomm_event_extended_header extended_header;
429
430 if (filter_expression) {
431 filter_len = strlen(filter_expression) + 1;
432 }
433
434 if (exclusion) {
435 nb_exclusions = exclusion->count;
436 }
437
438 if (probe_location) {
439 lttng_dynamic_buffer_init(&location_buffer);
440 ret = lttng_userspace_probe_location_serialize(probe_location,
441 &location_buffer, NULL);
442 if (ret < 0) {
443 ret = -1;
444 goto end;
445 }
446 userspace_probe_location_len = location_buffer.size;
447 }
448
449 /* Set header fields */
450 extended_header.filter_len = filter_len;
451 extended_header.nb_exclusions = nb_exclusions;
452 extended_header.userspace_probe_location_len = userspace_probe_location_len;
453
454 /* Copy header */
455 memcpy(*extended_at, &extended_header, sizeof(extended_header));
456 *extended_at += sizeof(extended_header);
457
458 /* Copy filter string */
459 if (filter_expression) {
460 memcpy(*extended_at, filter_expression, filter_len);
461 *extended_at += filter_len;
462 }
463
464 /* Copy exclusion names */
465 if (exclusion) {
466 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
467
468 memcpy(*extended_at, &exclusion->names, len);
469 *extended_at += len;
470 }
471
472 if (probe_location) {
473 memcpy(*extended_at, location_buffer.data, location_buffer.size);
474 *extended_at += location_buffer.size;
475 lttng_dynamic_buffer_reset(&location_buffer);
476 }
477 ret = 0;
478 end:
479 return ret;
480 }
481
482 /*
483 * Create a list of agent domain events.
484 *
485 * Return number of events in list on success or else a negative value.
486 */
487 static int list_lttng_agent_events(struct agent *agt,
488 struct lttng_event **events, size_t *total_size)
489 {
490 int i = 0, ret = 0;
491 unsigned int nb_event = 0;
492 struct agent_event *event;
493 struct lttng_event *tmp_events = NULL;
494 struct lttng_ht_iter iter;
495 size_t extended_len = 0;
496 void *extended_at;
497
498 assert(agt);
499 assert(events);
500
501 DBG3("Listing agent events");
502
503 rcu_read_lock();
504 nb_event = lttng_ht_get_count(agt->events);
505 rcu_read_unlock();
506 if (nb_event == 0) {
507 ret = nb_event;
508 *total_size = 0;
509 goto error;
510 }
511
512 /* Compute required extended infos size */
513 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
514
515 /*
516 * This is only valid because the commands which add events are
517 * processed in the same thread as the listing.
518 */
519 rcu_read_lock();
520 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
521 ret = increment_extended_len(event->filter_expression, NULL, NULL,
522 &extended_len);
523 if (ret) {
524 DBG("Error computing the length of extended info message");
525 ret = -LTTNG_ERR_FATAL;
526 goto error;
527 }
528 }
529 rcu_read_unlock();
530
531 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
532 tmp_events = zmalloc(*total_size);
533 if (!tmp_events) {
534 PERROR("zmalloc agent events session");
535 ret = -LTTNG_ERR_FATAL;
536 goto error;
537 }
538
539 extended_at = ((uint8_t *) tmp_events) +
540 nb_event * sizeof(struct lttng_event);
541
542 rcu_read_lock();
543 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
544 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
545 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
546 tmp_events[i].enabled = event->enabled;
547 tmp_events[i].loglevel = event->loglevel_value;
548 tmp_events[i].loglevel_type = event->loglevel_type;
549 i++;
550
551 /* Append extended info */
552 ret = append_extended_info(event->filter_expression, NULL, NULL,
553 &extended_at);
554 if (ret) {
555 DBG("Error appending extended info message");
556 ret = -LTTNG_ERR_FATAL;
557 goto error;
558 }
559 }
560
561 *events = tmp_events;
562 ret = nb_event;
563 assert(nb_event == i);
564
565 end:
566 rcu_read_unlock();
567 return ret;
568 error:
569 free(tmp_events);
570 goto end;
571 }
572
573 /*
574 * Create a list of ust global domain events.
575 */
576 static int list_lttng_ust_global_events(char *channel_name,
577 struct ltt_ust_domain_global *ust_global,
578 struct lttng_event **events, size_t *total_size)
579 {
580 int i = 0, ret = 0;
581 unsigned int nb_event = 0;
582 struct lttng_ht_iter iter;
583 struct lttng_ht_node_str *node;
584 struct ltt_ust_channel *uchan;
585 struct ltt_ust_event *uevent;
586 struct lttng_event *tmp;
587 size_t extended_len = 0;
588 void *extended_at;
589
590 DBG("Listing UST global events for channel %s", channel_name);
591
592 rcu_read_lock();
593
594 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
595 node = lttng_ht_iter_get_node_str(&iter);
596 if (node == NULL) {
597 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
598 goto end;
599 }
600
601 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
602
603 nb_event = lttng_ht_get_count(uchan->events);
604 if (nb_event == 0) {
605 ret = nb_event;
606 *total_size = 0;
607 goto end;
608 }
609
610 DBG3("Listing UST global %d events", nb_event);
611
612 /* Compute required extended infos size */
613 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
614 if (uevent->internal) {
615 nb_event--;
616 continue;
617 }
618
619 ret = increment_extended_len(uevent->filter_expression,
620 uevent->exclusion, NULL, &extended_len);
621 if (ret) {
622 DBG("Error computing the length of extended info message");
623 ret = -LTTNG_ERR_FATAL;
624 goto end;
625 }
626 }
627 if (nb_event == 0) {
628 /* All events are internal, skip. */
629 ret = 0;
630 *total_size = 0;
631 goto end;
632 }
633
634 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
635 tmp = zmalloc(*total_size);
636 if (tmp == NULL) {
637 ret = -LTTNG_ERR_FATAL;
638 goto end;
639 }
640
641 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
642
643 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
644 if (uevent->internal) {
645 /* This event should remain hidden from clients */
646 continue;
647 }
648 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
649 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
650 tmp[i].enabled = uevent->enabled;
651
652 switch (uevent->attr.instrumentation) {
653 case LTTNG_UST_TRACEPOINT:
654 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
655 break;
656 case LTTNG_UST_PROBE:
657 tmp[i].type = LTTNG_EVENT_PROBE;
658 break;
659 case LTTNG_UST_FUNCTION:
660 tmp[i].type = LTTNG_EVENT_FUNCTION;
661 break;
662 }
663
664 tmp[i].loglevel = uevent->attr.loglevel;
665 switch (uevent->attr.loglevel_type) {
666 case LTTNG_UST_LOGLEVEL_ALL:
667 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
668 break;
669 case LTTNG_UST_LOGLEVEL_RANGE:
670 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
671 break;
672 case LTTNG_UST_LOGLEVEL_SINGLE:
673 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
674 break;
675 }
676 if (uevent->filter) {
677 tmp[i].filter = 1;
678 }
679 if (uevent->exclusion) {
680 tmp[i].exclusion = 1;
681 }
682 i++;
683
684 /* Append extended info */
685 ret = append_extended_info(uevent->filter_expression,
686 uevent->exclusion, NULL, &extended_at);
687 if (ret) {
688 DBG("Error appending extended info message");
689 ret = -LTTNG_ERR_FATAL;
690 goto end;
691 }
692 }
693
694 ret = nb_event;
695 *events = tmp;
696 end:
697 rcu_read_unlock();
698 return ret;
699 }
700
701 /*
702 * Fill lttng_event array of all kernel events in the channel.
703 */
704 static int list_lttng_kernel_events(char *channel_name,
705 struct ltt_kernel_session *kernel_session,
706 struct lttng_event **events, size_t *total_size)
707 {
708 int i = 0, ret;
709 unsigned int nb_event;
710 struct ltt_kernel_event *event;
711 struct ltt_kernel_channel *kchan;
712 size_t extended_len = 0;
713 void *extended_at;
714
715 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
716 if (kchan == NULL) {
717 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
718 goto error;
719 }
720
721 nb_event = kchan->event_count;
722
723 DBG("Listing events for channel %s", kchan->channel->name);
724
725 if (nb_event == 0) {
726 *total_size = 0;
727 *events = NULL;
728 goto end;
729 }
730
731 /* Compute required extended infos size */
732 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
733 ret = increment_extended_len(event->filter_expression, NULL,
734 event->userspace_probe_location,
735 &extended_len);
736 if (ret) {
737 DBG("Error computing the length of extended info message");
738 ret = -LTTNG_ERR_FATAL;
739 goto error;
740 }
741 }
742
743 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
744 *events = zmalloc(*total_size);
745 if (*events == NULL) {
746 ret = -LTTNG_ERR_FATAL;
747 goto error;
748 }
749
750 extended_at = ((void *) *events) +
751 nb_event * sizeof(struct lttng_event);
752
753 /* Kernel channels */
754 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
755 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
756 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
757 (*events)[i].enabled = event->enabled;
758 (*events)[i].filter =
759 (unsigned char) !!event->filter_expression;
760
761 switch (event->event->instrumentation) {
762 case LTTNG_KERNEL_TRACEPOINT:
763 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
764 break;
765 case LTTNG_KERNEL_KRETPROBE:
766 (*events)[i].type = LTTNG_EVENT_FUNCTION;
767 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
768 sizeof(struct lttng_kernel_kprobe));
769 break;
770 case LTTNG_KERNEL_KPROBE:
771 (*events)[i].type = LTTNG_EVENT_PROBE;
772 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
773 sizeof(struct lttng_kernel_kprobe));
774 break;
775 case LTTNG_KERNEL_UPROBE:
776 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
777 break;
778 case LTTNG_KERNEL_FUNCTION:
779 (*events)[i].type = LTTNG_EVENT_FUNCTION;
780 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
781 sizeof(struct lttng_kernel_function));
782 break;
783 case LTTNG_KERNEL_NOOP:
784 (*events)[i].type = LTTNG_EVENT_NOOP;
785 break;
786 case LTTNG_KERNEL_SYSCALL:
787 (*events)[i].type = LTTNG_EVENT_SYSCALL;
788 break;
789 case LTTNG_KERNEL_ALL:
790 /* fall-through. */
791 default:
792 assert(0);
793 break;
794 }
795 i++;
796
797 /* Append extended info */
798 ret = append_extended_info(event->filter_expression, NULL,
799 event->userspace_probe_location, &extended_at);
800 if (ret) {
801 DBG("Error appending extended info message");
802 ret = -LTTNG_ERR_FATAL;
803 goto error;
804 }
805 }
806
807 end:
808 return nb_event;
809
810 error:
811 /* Negate the error code to differentiate the size from an error */
812 return -ret;
813 }
814
815 /*
816 * Add URI so the consumer output object. Set the correct path depending on the
817 * domain adding the default trace directory.
818 */
819 static int add_uri_to_consumer(struct consumer_output *consumer,
820 struct lttng_uri *uri, enum lttng_domain_type domain,
821 const char *session_name)
822 {
823 int ret = LTTNG_OK;
824 const char *default_trace_dir;
825
826 assert(uri);
827
828 if (consumer == NULL) {
829 DBG("No consumer detected. Don't add URI. Stopping.");
830 ret = LTTNG_ERR_NO_CONSUMER;
831 goto error;
832 }
833
834 switch (domain) {
835 case LTTNG_DOMAIN_KERNEL:
836 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
837 break;
838 case LTTNG_DOMAIN_UST:
839 default_trace_dir = DEFAULT_UST_TRACE_DIR;
840 break;
841 default:
842 /*
843 * This case is possible is we try to add the URI to the global tracing
844 * session consumer object which in this case there is no subdir.
845 */
846 default_trace_dir = "";
847 }
848
849 switch (uri->dtype) {
850 case LTTNG_DST_IPV4:
851 case LTTNG_DST_IPV6:
852 DBG2("Setting network URI to consumer");
853
854 if (consumer->type == CONSUMER_DST_NET) {
855 if ((uri->stype == LTTNG_STREAM_CONTROL &&
856 consumer->dst.net.control_isset) ||
857 (uri->stype == LTTNG_STREAM_DATA &&
858 consumer->dst.net.data_isset)) {
859 ret = LTTNG_ERR_URL_EXIST;
860 goto error;
861 }
862 } else {
863 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
864 }
865
866 consumer->type = CONSUMER_DST_NET;
867
868 /* Set URI into consumer output object */
869 ret = consumer_set_network_uri(consumer, uri);
870 if (ret < 0) {
871 ret = -ret;
872 goto error;
873 } else if (ret == 1) {
874 /*
875 * URI was the same in the consumer so we do not append the subdir
876 * again so to not duplicate output dir.
877 */
878 ret = LTTNG_OK;
879 goto error;
880 }
881
882 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
883 ret = consumer_set_subdir(consumer, session_name);
884 if (ret < 0) {
885 ret = LTTNG_ERR_FATAL;
886 goto error;
887 }
888 }
889
890 if (uri->stype == LTTNG_STREAM_CONTROL) {
891 /* On a new subdir, reappend the default trace dir. */
892 strncat(consumer->subdir, default_trace_dir,
893 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
894 DBG3("Append domain trace name to subdir %s", consumer->subdir);
895 }
896
897 break;
898 case LTTNG_DST_PATH:
899 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
900 memset(consumer->dst.session_root_path, 0,
901 sizeof(consumer->dst.session_root_path));
902 /* Explicit length checks for strcpy and strcat. */
903 if (strlen(uri->dst.path) + strlen(default_trace_dir)
904 >= sizeof(consumer->dst.session_root_path)) {
905 ret = LTTNG_ERR_FATAL;
906 goto error;
907 }
908 strcpy(consumer->dst.session_root_path, uri->dst.path);
909 /* Append default trace dir */
910 strcat(consumer->dst.session_root_path, default_trace_dir);
911 /* Flag consumer as local. */
912 consumer->type = CONSUMER_DST_LOCAL;
913 break;
914 }
915
916 ret = LTTNG_OK;
917
918 error:
919 return ret;
920 }
921
922 /*
923 * Init tracing by creating trace directory and sending fds kernel consumer.
924 */
925 static int init_kernel_tracing(struct ltt_kernel_session *session)
926 {
927 int ret = 0;
928 struct lttng_ht_iter iter;
929 struct consumer_socket *socket;
930
931 assert(session);
932
933 rcu_read_lock();
934
935 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
936 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
937 socket, node.node) {
938 pthread_mutex_lock(socket->lock);
939 ret = kernel_consumer_send_session(socket, session);
940 pthread_mutex_unlock(socket->lock);
941 if (ret < 0) {
942 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
943 goto error;
944 }
945 }
946 }
947
948 error:
949 rcu_read_unlock();
950 return ret;
951 }
952
953 /*
954 * Create a socket to the relayd using the URI.
955 *
956 * On success, the relayd_sock pointer is set to the created socket.
957 * Else, it remains untouched and an LTTng error code is returned.
958 */
959 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
960 struct lttcomm_relayd_sock **relayd_sock,
961 struct consumer_output *consumer)
962 {
963 int ret;
964 enum lttng_error_code status = LTTNG_OK;
965 struct lttcomm_relayd_sock *rsock;
966
967 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
968 RELAYD_VERSION_COMM_MINOR);
969 if (!rsock) {
970 status = LTTNG_ERR_FATAL;
971 goto error;
972 }
973
974 /*
975 * Connect to relayd so we can proceed with a session creation. This call
976 * can possibly block for an arbitrary amount of time to set the health
977 * state to be in poll execution.
978 */
979 health_poll_entry();
980 ret = relayd_connect(rsock);
981 health_poll_exit();
982 if (ret < 0) {
983 ERR("Unable to reach lttng-relayd");
984 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
985 goto free_sock;
986 }
987
988 /* Create socket for control stream. */
989 if (uri->stype == LTTNG_STREAM_CONTROL) {
990 DBG3("Creating relayd stream socket from URI");
991
992 /* Check relayd version */
993 ret = relayd_version_check(rsock);
994 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
995 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
996 goto close_sock;
997 } else if (ret < 0) {
998 ERR("Unable to reach lttng-relayd");
999 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1000 goto close_sock;
1001 }
1002 consumer->relay_major_version = rsock->major;
1003 consumer->relay_minor_version = rsock->minor;
1004 } else if (uri->stype == LTTNG_STREAM_DATA) {
1005 DBG3("Creating relayd data socket from URI");
1006 } else {
1007 /* Command is not valid */
1008 ERR("Relayd invalid stream type: %d", uri->stype);
1009 status = LTTNG_ERR_INVALID;
1010 goto close_sock;
1011 }
1012
1013 *relayd_sock = rsock;
1014
1015 return status;
1016
1017 close_sock:
1018 /* The returned value is not useful since we are on an error path. */
1019 (void) relayd_close(rsock);
1020 free_sock:
1021 free(rsock);
1022 error:
1023 return status;
1024 }
1025
1026 /*
1027 * Connect to the relayd using URI and send the socket to the right consumer.
1028 *
1029 * The consumer socket lock must be held by the caller.
1030 *
1031 * Returns LTTNG_OK on success or an LTTng error code on failure.
1032 */
1033 static enum lttng_error_code send_consumer_relayd_socket(
1034 unsigned int session_id,
1035 struct lttng_uri *relayd_uri,
1036 struct consumer_output *consumer,
1037 struct consumer_socket *consumer_sock,
1038 char *session_name, char *hostname, int session_live_timer)
1039 {
1040 int ret;
1041 struct lttcomm_relayd_sock *rsock = NULL;
1042 enum lttng_error_code status;
1043
1044 /* Connect to relayd and make version check if uri is the control. */
1045 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1046 if (status != LTTNG_OK) {
1047 goto relayd_comm_error;
1048 }
1049 assert(rsock);
1050
1051 /* Set the network sequence index if not set. */
1052 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1053 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1054 /*
1055 * Increment net_seq_idx because we are about to transfer the
1056 * new relayd socket to the consumer.
1057 * Assign unique key so the consumer can match streams.
1058 */
1059 consumer->net_seq_index = ++relayd_net_seq_idx;
1060 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1061 }
1062
1063 /* Send relayd socket to consumer. */
1064 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1065 relayd_uri->stype, session_id,
1066 session_name, hostname, session_live_timer);
1067 if (ret < 0) {
1068 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1069 goto close_sock;
1070 }
1071
1072 /* Flag that the corresponding socket was sent. */
1073 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1074 consumer_sock->control_sock_sent = 1;
1075 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1076 consumer_sock->data_sock_sent = 1;
1077 }
1078
1079 /*
1080 * Close socket which was dup on the consumer side. The session daemon does
1081 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1082 */
1083
1084 close_sock:
1085 if (status != LTTNG_OK) {
1086 /*
1087 * The consumer output for this session should not be used anymore
1088 * since the relayd connection failed thus making any tracing or/and
1089 * streaming not usable.
1090 */
1091 consumer->enabled = 0;
1092 }
1093 (void) relayd_close(rsock);
1094 free(rsock);
1095
1096 relayd_comm_error:
1097 return status;
1098 }
1099
1100 /*
1101 * Send both relayd sockets to a specific consumer and domain. This is a
1102 * helper function to facilitate sending the information to the consumer for a
1103 * session.
1104 *
1105 * The consumer socket lock must be held by the caller.
1106 *
1107 * Returns LTTNG_OK, or an LTTng error code on failure.
1108 */
1109 static enum lttng_error_code send_consumer_relayd_sockets(
1110 enum lttng_domain_type domain,
1111 unsigned int session_id, struct consumer_output *consumer,
1112 struct consumer_socket *sock, char *session_name,
1113 char *hostname, int session_live_timer)
1114 {
1115 enum lttng_error_code status = LTTNG_OK;
1116
1117 assert(consumer);
1118 assert(sock);
1119
1120 /* Sending control relayd socket. */
1121 if (!sock->control_sock_sent) {
1122 status = send_consumer_relayd_socket(session_id,
1123 &consumer->dst.net.control, consumer, sock,
1124 session_name, hostname, session_live_timer);
1125 if (status != LTTNG_OK) {
1126 goto error;
1127 }
1128 }
1129
1130 /* Sending data relayd socket. */
1131 if (!sock->data_sock_sent) {
1132 status = send_consumer_relayd_socket(session_id,
1133 &consumer->dst.net.data, consumer, sock,
1134 session_name, hostname, session_live_timer);
1135 if (status != LTTNG_OK) {
1136 goto error;
1137 }
1138 }
1139
1140 error:
1141 return status;
1142 }
1143
1144 /*
1145 * Setup relayd connections for a tracing session. First creates the socket to
1146 * the relayd and send them to the right domain consumer. Consumer type MUST be
1147 * network.
1148 */
1149 int cmd_setup_relayd(struct ltt_session *session)
1150 {
1151 int ret = LTTNG_OK;
1152 struct ltt_ust_session *usess;
1153 struct ltt_kernel_session *ksess;
1154 struct consumer_socket *socket;
1155 struct lttng_ht_iter iter;
1156
1157 assert(session);
1158
1159 usess = session->ust_session;
1160 ksess = session->kernel_session;
1161
1162 DBG("Setting relayd for session %s", session->name);
1163
1164 rcu_read_lock();
1165
1166 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1167 && usess->consumer->enabled) {
1168 /* For each consumer socket, send relayd sockets */
1169 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1170 socket, node.node) {
1171 pthread_mutex_lock(socket->lock);
1172 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1173 usess->consumer, socket,
1174 session->name, session->hostname,
1175 session->live_timer);
1176 pthread_mutex_unlock(socket->lock);
1177 if (ret != LTTNG_OK) {
1178 goto error;
1179 }
1180 /* Session is now ready for network streaming. */
1181 session->net_handle = 1;
1182 }
1183 session->consumer->relay_major_version =
1184 usess->consumer->relay_major_version;
1185 session->consumer->relay_minor_version =
1186 usess->consumer->relay_minor_version;
1187 }
1188
1189 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1190 && ksess->consumer->enabled) {
1191 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1192 socket, node.node) {
1193 pthread_mutex_lock(socket->lock);
1194 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1195 ksess->consumer, socket,
1196 session->name, session->hostname,
1197 session->live_timer);
1198 pthread_mutex_unlock(socket->lock);
1199 if (ret != LTTNG_OK) {
1200 goto error;
1201 }
1202 /* Session is now ready for network streaming. */
1203 session->net_handle = 1;
1204 }
1205 session->consumer->relay_major_version =
1206 ksess->consumer->relay_major_version;
1207 session->consumer->relay_minor_version =
1208 ksess->consumer->relay_minor_version;
1209 }
1210
1211 error:
1212 rcu_read_unlock();
1213 return ret;
1214 }
1215
1216 /*
1217 * Start a kernel session by opening all necessary streams.
1218 */
1219 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1220 {
1221 int ret;
1222 struct ltt_kernel_channel *kchan;
1223
1224 /* Open kernel metadata */
1225 if (ksess->metadata == NULL && ksess->output_traces) {
1226 ret = kernel_open_metadata(ksess);
1227 if (ret < 0) {
1228 ret = LTTNG_ERR_KERN_META_FAIL;
1229 goto error;
1230 }
1231 }
1232
1233 /* Open kernel metadata stream */
1234 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1235 ret = kernel_open_metadata_stream(ksess);
1236 if (ret < 0) {
1237 ERR("Kernel create metadata stream failed");
1238 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1239 goto error;
1240 }
1241 }
1242
1243 /* For each channel */
1244 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1245 if (kchan->stream_count == 0) {
1246 ret = kernel_open_channel_stream(kchan);
1247 if (ret < 0) {
1248 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1249 goto error;
1250 }
1251 /* Update the stream global counter */
1252 ksess->stream_count_global += ret;
1253 }
1254 }
1255
1256 /* Setup kernel consumer socket and send fds to it */
1257 ret = init_kernel_tracing(ksess);
1258 if (ret != 0) {
1259 ret = LTTNG_ERR_KERN_START_FAIL;
1260 goto error;
1261 }
1262
1263 /* This start the kernel tracing */
1264 ret = kernel_start_session(ksess);
1265 if (ret < 0) {
1266 ret = LTTNG_ERR_KERN_START_FAIL;
1267 goto error;
1268 }
1269
1270 /* Quiescent wait after starting trace */
1271 kernel_wait_quiescent(wpipe);
1272
1273 ksess->active = 1;
1274
1275 ret = LTTNG_OK;
1276
1277 error:
1278 return ret;
1279 }
1280
1281 /*
1282 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1283 */
1284 int cmd_disable_channel(struct ltt_session *session,
1285 enum lttng_domain_type domain, char *channel_name)
1286 {
1287 int ret;
1288 struct ltt_ust_session *usess;
1289
1290 usess = session->ust_session;
1291
1292 rcu_read_lock();
1293
1294 switch (domain) {
1295 case LTTNG_DOMAIN_KERNEL:
1296 {
1297 ret = channel_kernel_disable(session->kernel_session,
1298 channel_name);
1299 if (ret != LTTNG_OK) {
1300 goto error;
1301 }
1302
1303 kernel_wait_quiescent(kernel_tracer_fd);
1304 break;
1305 }
1306 case LTTNG_DOMAIN_UST:
1307 {
1308 struct ltt_ust_channel *uchan;
1309 struct lttng_ht *chan_ht;
1310
1311 chan_ht = usess->domain_global.channels;
1312
1313 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1314 if (uchan == NULL) {
1315 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1316 goto error;
1317 }
1318
1319 ret = channel_ust_disable(usess, uchan);
1320 if (ret != LTTNG_OK) {
1321 goto error;
1322 }
1323 break;
1324 }
1325 default:
1326 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1327 goto error;
1328 }
1329
1330 ret = LTTNG_OK;
1331
1332 error:
1333 rcu_read_unlock();
1334 return ret;
1335 }
1336
1337 /*
1338 * Command LTTNG_TRACK_PID processed by the client thread.
1339 *
1340 * Called with session lock held.
1341 */
1342 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1343 int pid)
1344 {
1345 int ret;
1346
1347 rcu_read_lock();
1348
1349 switch (domain) {
1350 case LTTNG_DOMAIN_KERNEL:
1351 {
1352 struct ltt_kernel_session *ksess;
1353
1354 ksess = session->kernel_session;
1355
1356 ret = kernel_track_pid(ksess, pid);
1357 if (ret != LTTNG_OK) {
1358 goto error;
1359 }
1360
1361 kernel_wait_quiescent(kernel_tracer_fd);
1362 break;
1363 }
1364 case LTTNG_DOMAIN_UST:
1365 {
1366 struct ltt_ust_session *usess;
1367
1368 usess = session->ust_session;
1369
1370 ret = trace_ust_track_pid(usess, pid);
1371 if (ret != LTTNG_OK) {
1372 goto error;
1373 }
1374 break;
1375 }
1376 default:
1377 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1378 goto error;
1379 }
1380
1381 ret = LTTNG_OK;
1382
1383 error:
1384 rcu_read_unlock();
1385 return ret;
1386 }
1387
1388 /*
1389 * Command LTTNG_UNTRACK_PID processed by the client thread.
1390 *
1391 * Called with session lock held.
1392 */
1393 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1394 int pid)
1395 {
1396 int ret;
1397
1398 rcu_read_lock();
1399
1400 switch (domain) {
1401 case LTTNG_DOMAIN_KERNEL:
1402 {
1403 struct ltt_kernel_session *ksess;
1404
1405 ksess = session->kernel_session;
1406
1407 ret = kernel_untrack_pid(ksess, pid);
1408 if (ret != LTTNG_OK) {
1409 goto error;
1410 }
1411
1412 kernel_wait_quiescent(kernel_tracer_fd);
1413 break;
1414 }
1415 case LTTNG_DOMAIN_UST:
1416 {
1417 struct ltt_ust_session *usess;
1418
1419 usess = session->ust_session;
1420
1421 ret = trace_ust_untrack_pid(usess, pid);
1422 if (ret != LTTNG_OK) {
1423 goto error;
1424 }
1425 break;
1426 }
1427 default:
1428 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1429 goto error;
1430 }
1431
1432 ret = LTTNG_OK;
1433
1434 error:
1435 rcu_read_unlock();
1436 return ret;
1437 }
1438
1439 /*
1440 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1441 *
1442 * The wpipe arguments is used as a notifier for the kernel thread.
1443 */
1444 int cmd_enable_channel(struct ltt_session *session,
1445 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1446 {
1447 int ret;
1448 struct ltt_ust_session *usess = session->ust_session;
1449 struct lttng_ht *chan_ht;
1450 size_t len;
1451
1452 assert(session);
1453 assert(attr);
1454 assert(domain);
1455
1456 len = lttng_strnlen(attr->name, sizeof(attr->name));
1457
1458 /* Validate channel name */
1459 if (attr->name[0] == '.' ||
1460 memchr(attr->name, '/', len) != NULL) {
1461 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1462 goto end;
1463 }
1464
1465 DBG("Enabling channel %s for session %s", attr->name, session->name);
1466
1467 rcu_read_lock();
1468
1469 /*
1470 * Don't try to enable a channel if the session has been started at
1471 * some point in time before. The tracer does not allow it.
1472 */
1473 if (session->has_been_started) {
1474 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1475 goto error;
1476 }
1477
1478 /*
1479 * If the session is a live session, remove the switch timer, the
1480 * live timer does the same thing but sends also synchronisation
1481 * beacons for inactive streams.
1482 */
1483 if (session->live_timer > 0) {
1484 attr->attr.live_timer_interval = session->live_timer;
1485 attr->attr.switch_timer_interval = 0;
1486 }
1487
1488 /* Check for feature support */
1489 switch (domain->type) {
1490 case LTTNG_DOMAIN_KERNEL:
1491 {
1492 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1493 /* Sampling position of buffer is not supported */
1494 WARN("Kernel tracer does not support buffer monitoring. "
1495 "Setting the monitor interval timer to 0 "
1496 "(disabled) for channel '%s' of session '%s'",
1497 attr-> name, session->name);
1498 lttng_channel_set_monitor_timer_interval(attr, 0);
1499 }
1500 break;
1501 }
1502 case LTTNG_DOMAIN_UST:
1503 break;
1504 case LTTNG_DOMAIN_JUL:
1505 case LTTNG_DOMAIN_LOG4J:
1506 case LTTNG_DOMAIN_PYTHON:
1507 if (!agent_tracing_is_enabled()) {
1508 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1509 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1510 goto error;
1511 }
1512 break;
1513 default:
1514 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1515 goto error;
1516 }
1517
1518 switch (domain->type) {
1519 case LTTNG_DOMAIN_KERNEL:
1520 {
1521 struct ltt_kernel_channel *kchan;
1522
1523 kchan = trace_kernel_get_channel_by_name(attr->name,
1524 session->kernel_session);
1525 if (kchan == NULL) {
1526 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1527 if (attr->name[0] != '\0') {
1528 session->kernel_session->has_non_default_channel = 1;
1529 }
1530 } else {
1531 ret = channel_kernel_enable(session->kernel_session, kchan);
1532 }
1533
1534 if (ret != LTTNG_OK) {
1535 goto error;
1536 }
1537
1538 kernel_wait_quiescent(kernel_tracer_fd);
1539 break;
1540 }
1541 case LTTNG_DOMAIN_UST:
1542 case LTTNG_DOMAIN_JUL:
1543 case LTTNG_DOMAIN_LOG4J:
1544 case LTTNG_DOMAIN_PYTHON:
1545 {
1546 struct ltt_ust_channel *uchan;
1547
1548 /*
1549 * FIXME
1550 *
1551 * Current agent implementation limitations force us to allow
1552 * only one channel at once in "agent" subdomains. Each
1553 * subdomain has a default channel name which must be strictly
1554 * adhered to.
1555 */
1556 if (domain->type == LTTNG_DOMAIN_JUL) {
1557 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1558 LTTNG_SYMBOL_NAME_LEN)) {
1559 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1560 goto error;
1561 }
1562 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1563 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1564 LTTNG_SYMBOL_NAME_LEN)) {
1565 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1566 goto error;
1567 }
1568 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1569 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1570 LTTNG_SYMBOL_NAME_LEN)) {
1571 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1572 goto error;
1573 }
1574 }
1575
1576 chan_ht = usess->domain_global.channels;
1577
1578 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1579 if (uchan == NULL) {
1580 ret = channel_ust_create(usess, attr, domain->buf_type);
1581 if (attr->name[0] != '\0') {
1582 usess->has_non_default_channel = 1;
1583 }
1584 } else {
1585 ret = channel_ust_enable(usess, uchan);
1586 }
1587 break;
1588 }
1589 default:
1590 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1591 goto error;
1592 }
1593
1594 error:
1595 rcu_read_unlock();
1596 end:
1597 return ret;
1598 }
1599
1600 /*
1601 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1602 */
1603 int cmd_disable_event(struct ltt_session *session,
1604 enum lttng_domain_type domain, char *channel_name,
1605 struct lttng_event *event)
1606 {
1607 int ret;
1608 char *event_name;
1609
1610 DBG("Disable event command for event \'%s\'", event->name);
1611
1612 event_name = event->name;
1613
1614 /* Error out on unhandled search criteria */
1615 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1616 || event->pid || event->filter || event->exclusion) {
1617 ret = LTTNG_ERR_UNK;
1618 goto error;
1619 }
1620
1621 rcu_read_lock();
1622
1623 switch (domain) {
1624 case LTTNG_DOMAIN_KERNEL:
1625 {
1626 struct ltt_kernel_channel *kchan;
1627 struct ltt_kernel_session *ksess;
1628
1629 ksess = session->kernel_session;
1630
1631 /*
1632 * If a non-default channel has been created in the
1633 * session, explicitely require that -c chan_name needs
1634 * to be provided.
1635 */
1636 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1637 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1638 goto error_unlock;
1639 }
1640
1641 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1642 if (kchan == NULL) {
1643 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1644 goto error_unlock;
1645 }
1646
1647 switch (event->type) {
1648 case LTTNG_EVENT_ALL:
1649 case LTTNG_EVENT_TRACEPOINT:
1650 case LTTNG_EVENT_SYSCALL:
1651 case LTTNG_EVENT_PROBE:
1652 case LTTNG_EVENT_FUNCTION:
1653 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1654 if (event_name[0] == '\0') {
1655 ret = event_kernel_disable_event(kchan,
1656 NULL, event->type);
1657 } else {
1658 ret = event_kernel_disable_event(kchan,
1659 event_name, event->type);
1660 }
1661 if (ret != LTTNG_OK) {
1662 goto error_unlock;
1663 }
1664 break;
1665 default:
1666 ret = LTTNG_ERR_UNK;
1667 goto error_unlock;
1668 }
1669
1670 kernel_wait_quiescent(kernel_tracer_fd);
1671 break;
1672 }
1673 case LTTNG_DOMAIN_UST:
1674 {
1675 struct ltt_ust_channel *uchan;
1676 struct ltt_ust_session *usess;
1677
1678 usess = session->ust_session;
1679
1680 if (validate_ust_event_name(event_name)) {
1681 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1682 goto error_unlock;
1683 }
1684
1685 /*
1686 * If a non-default channel has been created in the
1687 * session, explicitly require that -c chan_name needs
1688 * to be provided.
1689 */
1690 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1691 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1692 goto error_unlock;
1693 }
1694
1695 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1696 channel_name);
1697 if (uchan == NULL) {
1698 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1699 goto error_unlock;
1700 }
1701
1702 switch (event->type) {
1703 case LTTNG_EVENT_ALL:
1704 /*
1705 * An empty event name means that everything
1706 * should be disabled.
1707 */
1708 if (event->name[0] == '\0') {
1709 ret = event_ust_disable_all_tracepoints(usess, uchan);
1710 } else {
1711 ret = event_ust_disable_tracepoint(usess, uchan,
1712 event_name);
1713 }
1714 if (ret != LTTNG_OK) {
1715 goto error_unlock;
1716 }
1717 break;
1718 default:
1719 ret = LTTNG_ERR_UNK;
1720 goto error_unlock;
1721 }
1722
1723 DBG3("Disable UST event %s in channel %s completed", event_name,
1724 channel_name);
1725 break;
1726 }
1727 case LTTNG_DOMAIN_LOG4J:
1728 case LTTNG_DOMAIN_JUL:
1729 case LTTNG_DOMAIN_PYTHON:
1730 {
1731 struct agent *agt;
1732 struct ltt_ust_session *usess = session->ust_session;
1733
1734 assert(usess);
1735
1736 switch (event->type) {
1737 case LTTNG_EVENT_ALL:
1738 break;
1739 default:
1740 ret = LTTNG_ERR_UNK;
1741 goto error_unlock;
1742 }
1743
1744 agt = trace_ust_find_agent(usess, domain);
1745 if (!agt) {
1746 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1747 goto error_unlock;
1748 }
1749 /*
1750 * An empty event name means that everything
1751 * should be disabled.
1752 */
1753 if (event->name[0] == '\0') {
1754 ret = event_agent_disable_all(usess, agt);
1755 } else {
1756 ret = event_agent_disable(usess, agt, event_name);
1757 }
1758 if (ret != LTTNG_OK) {
1759 goto error_unlock;
1760 }
1761
1762 break;
1763 }
1764 default:
1765 ret = LTTNG_ERR_UND;
1766 goto error_unlock;
1767 }
1768
1769 ret = LTTNG_OK;
1770
1771 error_unlock:
1772 rcu_read_unlock();
1773 error:
1774 return ret;
1775 }
1776
1777 /*
1778 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1779 */
1780 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1781 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1782 {
1783 int ret, chan_kern_created = 0, chan_ust_created = 0;
1784 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1785
1786 /*
1787 * Don't try to add a context if the session has been started at
1788 * some point in time before. The tracer does not allow it and would
1789 * result in a corrupted trace.
1790 */
1791 if (session->has_been_started) {
1792 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1793 goto end;
1794 }
1795
1796 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1797 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1798 app_ctx_name = ctx->u.app_ctx.ctx_name;
1799 }
1800
1801 switch (domain) {
1802 case LTTNG_DOMAIN_KERNEL:
1803 assert(session->kernel_session);
1804
1805 if (session->kernel_session->channel_count == 0) {
1806 /* Create default channel */
1807 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1808 if (ret != LTTNG_OK) {
1809 goto error;
1810 }
1811 chan_kern_created = 1;
1812 }
1813 /* Add kernel context to kernel tracer */
1814 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1815 if (ret != LTTNG_OK) {
1816 goto error;
1817 }
1818 break;
1819 case LTTNG_DOMAIN_JUL:
1820 case LTTNG_DOMAIN_LOG4J:
1821 {
1822 /*
1823 * Validate channel name.
1824 * If no channel name is given and the domain is JUL or LOG4J,
1825 * set it to the appropriate domain-specific channel name. If
1826 * a name is provided but does not match the expexted channel
1827 * name, return an error.
1828 */
1829 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1830 strcmp(channel_name,
1831 DEFAULT_JUL_CHANNEL_NAME)) {
1832 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1833 goto error;
1834 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1835 strcmp(channel_name,
1836 DEFAULT_LOG4J_CHANNEL_NAME)) {
1837 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1838 goto error;
1839 }
1840 /* break is _not_ missing here. */
1841 }
1842 case LTTNG_DOMAIN_UST:
1843 {
1844 struct ltt_ust_session *usess = session->ust_session;
1845 unsigned int chan_count;
1846
1847 assert(usess);
1848
1849 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1850 if (chan_count == 0) {
1851 struct lttng_channel *attr;
1852 /* Create default channel */
1853 attr = channel_new_default_attr(domain, usess->buffer_type);
1854 if (attr == NULL) {
1855 ret = LTTNG_ERR_FATAL;
1856 goto error;
1857 }
1858
1859 ret = channel_ust_create(usess, attr, usess->buffer_type);
1860 if (ret != LTTNG_OK) {
1861 free(attr);
1862 goto error;
1863 }
1864 channel_attr_destroy(attr);
1865 chan_ust_created = 1;
1866 }
1867
1868 ret = context_ust_add(usess, domain, ctx, channel_name);
1869 free(app_ctx_provider_name);
1870 free(app_ctx_name);
1871 app_ctx_name = NULL;
1872 app_ctx_provider_name = NULL;
1873 if (ret != LTTNG_OK) {
1874 goto error;
1875 }
1876 break;
1877 }
1878 default:
1879 ret = LTTNG_ERR_UND;
1880 goto error;
1881 }
1882
1883 ret = LTTNG_OK;
1884 goto end;
1885
1886 error:
1887 if (chan_kern_created) {
1888 struct ltt_kernel_channel *kchan =
1889 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1890 session->kernel_session);
1891 /* Created previously, this should NOT fail. */
1892 assert(kchan);
1893 kernel_destroy_channel(kchan);
1894 }
1895
1896 if (chan_ust_created) {
1897 struct ltt_ust_channel *uchan =
1898 trace_ust_find_channel_by_name(
1899 session->ust_session->domain_global.channels,
1900 DEFAULT_CHANNEL_NAME);
1901 /* Created previously, this should NOT fail. */
1902 assert(uchan);
1903 /* Remove from the channel list of the session. */
1904 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1905 uchan);
1906 trace_ust_destroy_channel(uchan);
1907 }
1908 end:
1909 free(app_ctx_provider_name);
1910 free(app_ctx_name);
1911 return ret;
1912 }
1913
1914 static inline bool name_starts_with(const char *name, const char *prefix)
1915 {
1916 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1917
1918 return !strncmp(name, prefix, max_cmp_len);
1919 }
1920
1921 /* Perform userspace-specific event name validation */
1922 static int validate_ust_event_name(const char *name)
1923 {
1924 int ret = 0;
1925
1926 if (!name) {
1927 ret = -1;
1928 goto end;
1929 }
1930
1931 /*
1932 * Check name against all internal UST event component namespaces used
1933 * by the agents.
1934 */
1935 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1936 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1937 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1938 ret = -1;
1939 }
1940
1941 end:
1942 return ret;
1943 }
1944
1945 /*
1946 * Internal version of cmd_enable_event() with a supplemental
1947 * "internal_event" flag which is used to enable internal events which should
1948 * be hidden from clients. Such events are used in the agent implementation to
1949 * enable the events through which all "agent" events are funeled.
1950 */
1951 static int _cmd_enable_event(struct ltt_session *session,
1952 struct lttng_domain *domain,
1953 char *channel_name, struct lttng_event *event,
1954 char *filter_expression,
1955 struct lttng_filter_bytecode *filter,
1956 struct lttng_event_exclusion *exclusion,
1957 int wpipe, bool internal_event)
1958 {
1959 int ret = 0, channel_created = 0;
1960 struct lttng_channel *attr = NULL;
1961
1962 assert(session);
1963 assert(event);
1964 assert(channel_name);
1965
1966 /* If we have a filter, we must have its filter expression */
1967 assert(!(!!filter_expression ^ !!filter));
1968
1969 /* Normalize event name as a globbing pattern */
1970 strutils_normalize_star_glob_pattern(event->name);
1971
1972 /* Normalize exclusion names as globbing patterns */
1973 if (exclusion) {
1974 size_t i;
1975
1976 for (i = 0; i < exclusion->count; i++) {
1977 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
1978
1979 strutils_normalize_star_glob_pattern(name);
1980 }
1981 }
1982
1983 DBG("Enable event command for event \'%s\'", event->name);
1984
1985 rcu_read_lock();
1986
1987 switch (domain->type) {
1988 case LTTNG_DOMAIN_KERNEL:
1989 {
1990 struct ltt_kernel_channel *kchan;
1991
1992 /*
1993 * If a non-default channel has been created in the
1994 * session, explicitely require that -c chan_name needs
1995 * to be provided.
1996 */
1997 if (session->kernel_session->has_non_default_channel
1998 && channel_name[0] == '\0') {
1999 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2000 goto error;
2001 }
2002
2003 kchan = trace_kernel_get_channel_by_name(channel_name,
2004 session->kernel_session);
2005 if (kchan == NULL) {
2006 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2007 LTTNG_BUFFER_GLOBAL);
2008 if (attr == NULL) {
2009 ret = LTTNG_ERR_FATAL;
2010 goto error;
2011 }
2012 if (lttng_strncpy(attr->name, channel_name,
2013 sizeof(attr->name))) {
2014 ret = LTTNG_ERR_INVALID;
2015 goto error;
2016 }
2017
2018 ret = cmd_enable_channel(session, domain, attr, wpipe);
2019 if (ret != LTTNG_OK) {
2020 goto error;
2021 }
2022 channel_created = 1;
2023 }
2024
2025 /* Get the newly created kernel channel pointer */
2026 kchan = trace_kernel_get_channel_by_name(channel_name,
2027 session->kernel_session);
2028 if (kchan == NULL) {
2029 /* This sould not happen... */
2030 ret = LTTNG_ERR_FATAL;
2031 goto error;
2032 }
2033
2034 switch (event->type) {
2035 case LTTNG_EVENT_ALL:
2036 {
2037 char *filter_expression_a = NULL;
2038 struct lttng_filter_bytecode *filter_a = NULL;
2039
2040 /*
2041 * We need to duplicate filter_expression and filter,
2042 * because ownership is passed to first enable
2043 * event.
2044 */
2045 if (filter_expression) {
2046 filter_expression_a = strdup(filter_expression);
2047 if (!filter_expression_a) {
2048 ret = LTTNG_ERR_FATAL;
2049 goto error;
2050 }
2051 }
2052 if (filter) {
2053 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2054 if (!filter_a) {
2055 free(filter_expression_a);
2056 ret = LTTNG_ERR_FATAL;
2057 goto error;
2058 }
2059 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2060 }
2061 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2062 ret = event_kernel_enable_event(kchan, event,
2063 filter_expression, filter);
2064 /* We have passed ownership */
2065 filter_expression = NULL;
2066 filter = NULL;
2067 if (ret != LTTNG_OK) {
2068 if (channel_created) {
2069 /* Let's not leak a useless channel. */
2070 kernel_destroy_channel(kchan);
2071 }
2072 free(filter_expression_a);
2073 free(filter_a);
2074 goto error;
2075 }
2076 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2077 ret = event_kernel_enable_event(kchan, event,
2078 filter_expression_a, filter_a);
2079 /* We have passed ownership */
2080 filter_expression_a = NULL;
2081 filter_a = NULL;
2082 if (ret != LTTNG_OK) {
2083 goto error;
2084 }
2085 break;
2086 }
2087 case LTTNG_EVENT_PROBE:
2088 case LTTNG_EVENT_USERSPACE_PROBE:
2089 case LTTNG_EVENT_FUNCTION:
2090 case LTTNG_EVENT_FUNCTION_ENTRY:
2091 case LTTNG_EVENT_TRACEPOINT:
2092 ret = event_kernel_enable_event(kchan, event,
2093 filter_expression, filter);
2094 /* We have passed ownership */
2095 filter_expression = NULL;
2096 filter = NULL;
2097 if (ret != LTTNG_OK) {
2098 if (channel_created) {
2099 /* Let's not leak a useless channel. */
2100 kernel_destroy_channel(kchan);
2101 }
2102 goto error;
2103 }
2104 break;
2105 case LTTNG_EVENT_SYSCALL:
2106 ret = event_kernel_enable_event(kchan, event,
2107 filter_expression, filter);
2108 /* We have passed ownership */
2109 filter_expression = NULL;
2110 filter = NULL;
2111 if (ret != LTTNG_OK) {
2112 goto error;
2113 }
2114 break;
2115 default:
2116 ret = LTTNG_ERR_UNK;
2117 goto error;
2118 }
2119
2120 kernel_wait_quiescent(kernel_tracer_fd);
2121 break;
2122 }
2123 case LTTNG_DOMAIN_UST:
2124 {
2125 struct ltt_ust_channel *uchan;
2126 struct ltt_ust_session *usess = session->ust_session;
2127
2128 assert(usess);
2129
2130 /*
2131 * If a non-default channel has been created in the
2132 * session, explicitely require that -c chan_name needs
2133 * to be provided.
2134 */
2135 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2136 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2137 goto error;
2138 }
2139
2140 /* Get channel from global UST domain */
2141 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2142 channel_name);
2143 if (uchan == NULL) {
2144 /* Create default channel */
2145 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2146 usess->buffer_type);
2147 if (attr == NULL) {
2148 ret = LTTNG_ERR_FATAL;
2149 goto error;
2150 }
2151 if (lttng_strncpy(attr->name, channel_name,
2152 sizeof(attr->name))) {
2153 ret = LTTNG_ERR_INVALID;
2154 goto error;
2155 }
2156
2157 ret = cmd_enable_channel(session, domain, attr, wpipe);
2158 if (ret != LTTNG_OK) {
2159 goto error;
2160 }
2161
2162 /* Get the newly created channel reference back */
2163 uchan = trace_ust_find_channel_by_name(
2164 usess->domain_global.channels, channel_name);
2165 assert(uchan);
2166 }
2167
2168 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2169 /*
2170 * Don't allow users to add UST events to channels which
2171 * are assigned to a userspace subdomain (JUL, Log4J,
2172 * Python, etc.).
2173 */
2174 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2175 goto error;
2176 }
2177
2178 if (!internal_event) {
2179 /*
2180 * Ensure the event name is not reserved for internal
2181 * use.
2182 */
2183 ret = validate_ust_event_name(event->name);
2184 if (ret) {
2185 WARN("Userspace event name %s failed validation.",
2186 event->name);
2187 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2188 goto error;
2189 }
2190 }
2191
2192 /* At this point, the session and channel exist on the tracer */
2193 ret = event_ust_enable_tracepoint(usess, uchan, event,
2194 filter_expression, filter, exclusion,
2195 internal_event);
2196 /* We have passed ownership */
2197 filter_expression = NULL;
2198 filter = NULL;
2199 exclusion = NULL;
2200 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2201 goto already_enabled;
2202 } else if (ret != LTTNG_OK) {
2203 goto error;
2204 }
2205 break;
2206 }
2207 case LTTNG_DOMAIN_LOG4J:
2208 case LTTNG_DOMAIN_JUL:
2209 case LTTNG_DOMAIN_PYTHON:
2210 {
2211 const char *default_event_name, *default_chan_name;
2212 struct agent *agt;
2213 struct lttng_event uevent;
2214 struct lttng_domain tmp_dom;
2215 struct ltt_ust_session *usess = session->ust_session;
2216
2217 assert(usess);
2218
2219 if (!agent_tracing_is_enabled()) {
2220 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2221 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2222 goto error;
2223 }
2224
2225 agt = trace_ust_find_agent(usess, domain->type);
2226 if (!agt) {
2227 agt = agent_create(domain->type);
2228 if (!agt) {
2229 ret = LTTNG_ERR_NOMEM;
2230 goto error;
2231 }
2232 agent_add(agt, usess->agents);
2233 }
2234
2235 /* Create the default tracepoint. */
2236 memset(&uevent, 0, sizeof(uevent));
2237 uevent.type = LTTNG_EVENT_TRACEPOINT;
2238 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2239 default_event_name = event_get_default_agent_ust_name(
2240 domain->type);
2241 if (!default_event_name) {
2242 ret = LTTNG_ERR_FATAL;
2243 goto error;
2244 }
2245 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2246 uevent.name[sizeof(uevent.name) - 1] = '\0';
2247
2248 /*
2249 * The domain type is changed because we are about to enable the
2250 * default channel and event for the JUL domain that are hardcoded.
2251 * This happens in the UST domain.
2252 */
2253 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2254 tmp_dom.type = LTTNG_DOMAIN_UST;
2255
2256 switch (domain->type) {
2257 case LTTNG_DOMAIN_LOG4J:
2258 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2259 break;
2260 case LTTNG_DOMAIN_JUL:
2261 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2262 break;
2263 case LTTNG_DOMAIN_PYTHON:
2264 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2265 break;
2266 default:
2267 /* The switch/case we are in makes this impossible */
2268 assert(0);
2269 }
2270
2271 {
2272 char *filter_expression_copy = NULL;
2273 struct lttng_filter_bytecode *filter_copy = NULL;
2274
2275 if (filter) {
2276 const size_t filter_size = sizeof(
2277 struct lttng_filter_bytecode)
2278 + filter->len;
2279
2280 filter_copy = zmalloc(filter_size);
2281 if (!filter_copy) {
2282 ret = LTTNG_ERR_NOMEM;
2283 goto error;
2284 }
2285 memcpy(filter_copy, filter, filter_size);
2286
2287 filter_expression_copy =
2288 strdup(filter_expression);
2289 if (!filter_expression) {
2290 ret = LTTNG_ERR_NOMEM;
2291 }
2292
2293 if (!filter_expression_copy || !filter_copy) {
2294 free(filter_expression_copy);
2295 free(filter_copy);
2296 goto error;
2297 }
2298 }
2299
2300 ret = cmd_enable_event_internal(session, &tmp_dom,
2301 (char *) default_chan_name,
2302 &uevent, filter_expression_copy,
2303 filter_copy, NULL, wpipe);
2304 }
2305
2306 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2307 goto already_enabled;
2308 } else if (ret != LTTNG_OK) {
2309 goto error;
2310 }
2311
2312 /* The wild card * means that everything should be enabled. */
2313 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2314 ret = event_agent_enable_all(usess, agt, event, filter,
2315 filter_expression);
2316 } else {
2317 ret = event_agent_enable(usess, agt, event, filter,
2318 filter_expression);
2319 }
2320 filter = NULL;
2321 filter_expression = NULL;
2322 if (ret != LTTNG_OK) {
2323 goto error;
2324 }
2325
2326 break;
2327 }
2328 default:
2329 ret = LTTNG_ERR_UND;
2330 goto error;
2331 }
2332
2333 ret = LTTNG_OK;
2334
2335 already_enabled:
2336 error:
2337 free(filter_expression);
2338 free(filter);
2339 free(exclusion);
2340 channel_attr_destroy(attr);
2341 rcu_read_unlock();
2342 return ret;
2343 }
2344
2345 /*
2346 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2347 * We own filter, exclusion, and filter_expression.
2348 */
2349 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2350 char *channel_name, struct lttng_event *event,
2351 char *filter_expression,
2352 struct lttng_filter_bytecode *filter,
2353 struct lttng_event_exclusion *exclusion,
2354 int wpipe)
2355 {
2356 return _cmd_enable_event(session, domain, channel_name, event,
2357 filter_expression, filter, exclusion, wpipe, false);
2358 }
2359
2360 /*
2361 * Enable an event which is internal to LTTng. An internal should
2362 * never be made visible to clients and are immune to checks such as
2363 * reserved names.
2364 */
2365 static int cmd_enable_event_internal(struct ltt_session *session,
2366 struct lttng_domain *domain,
2367 char *channel_name, struct lttng_event *event,
2368 char *filter_expression,
2369 struct lttng_filter_bytecode *filter,
2370 struct lttng_event_exclusion *exclusion,
2371 int wpipe)
2372 {
2373 return _cmd_enable_event(session, domain, channel_name, event,
2374 filter_expression, filter, exclusion, wpipe, true);
2375 }
2376
2377 /*
2378 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2379 */
2380 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2381 struct lttng_event **events)
2382 {
2383 int ret;
2384 ssize_t nb_events = 0;
2385
2386 switch (domain) {
2387 case LTTNG_DOMAIN_KERNEL:
2388 nb_events = kernel_list_events(kernel_tracer_fd, events);
2389 if (nb_events < 0) {
2390 ret = LTTNG_ERR_KERN_LIST_FAIL;
2391 goto error;
2392 }
2393 break;
2394 case LTTNG_DOMAIN_UST:
2395 nb_events = ust_app_list_events(events);
2396 if (nb_events < 0) {
2397 ret = LTTNG_ERR_UST_LIST_FAIL;
2398 goto error;
2399 }
2400 break;
2401 case LTTNG_DOMAIN_LOG4J:
2402 case LTTNG_DOMAIN_JUL:
2403 case LTTNG_DOMAIN_PYTHON:
2404 nb_events = agent_list_events(events, domain);
2405 if (nb_events < 0) {
2406 ret = LTTNG_ERR_UST_LIST_FAIL;
2407 goto error;
2408 }
2409 break;
2410 default:
2411 ret = LTTNG_ERR_UND;
2412 goto error;
2413 }
2414
2415 return nb_events;
2416
2417 error:
2418 /* Return negative value to differentiate return code */
2419 return -ret;
2420 }
2421
2422 /*
2423 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2424 */
2425 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2426 struct lttng_event_field **fields)
2427 {
2428 int ret;
2429 ssize_t nb_fields = 0;
2430
2431 switch (domain) {
2432 case LTTNG_DOMAIN_UST:
2433 nb_fields = ust_app_list_event_fields(fields);
2434 if (nb_fields < 0) {
2435 ret = LTTNG_ERR_UST_LIST_FAIL;
2436 goto error;
2437 }
2438 break;
2439 case LTTNG_DOMAIN_KERNEL:
2440 default: /* fall-through */
2441 ret = LTTNG_ERR_UND;
2442 goto error;
2443 }
2444
2445 return nb_fields;
2446
2447 error:
2448 /* Return negative value to differentiate return code */
2449 return -ret;
2450 }
2451
2452 ssize_t cmd_list_syscalls(struct lttng_event **events)
2453 {
2454 return syscall_table_list(events);
2455 }
2456
2457 /*
2458 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2459 *
2460 * Called with session lock held.
2461 */
2462 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2463 enum lttng_domain_type domain, int32_t **pids)
2464 {
2465 int ret;
2466 ssize_t nr_pids = 0;
2467
2468 switch (domain) {
2469 case LTTNG_DOMAIN_KERNEL:
2470 {
2471 struct ltt_kernel_session *ksess;
2472
2473 ksess = session->kernel_session;
2474 nr_pids = kernel_list_tracker_pids(ksess, pids);
2475 if (nr_pids < 0) {
2476 ret = LTTNG_ERR_KERN_LIST_FAIL;
2477 goto error;
2478 }
2479 break;
2480 }
2481 case LTTNG_DOMAIN_UST:
2482 {
2483 struct ltt_ust_session *usess;
2484
2485 usess = session->ust_session;
2486 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2487 if (nr_pids < 0) {
2488 ret = LTTNG_ERR_UST_LIST_FAIL;
2489 goto error;
2490 }
2491 break;
2492 }
2493 case LTTNG_DOMAIN_LOG4J:
2494 case LTTNG_DOMAIN_JUL:
2495 case LTTNG_DOMAIN_PYTHON:
2496 default:
2497 ret = LTTNG_ERR_UND;
2498 goto error;
2499 }
2500
2501 return nr_pids;
2502
2503 error:
2504 /* Return negative value to differentiate return code */
2505 return -ret;
2506 }
2507
2508 static
2509 int domain_mkdir(const struct consumer_output *output,
2510 const struct ltt_session *session,
2511 uid_t uid, gid_t gid)
2512 {
2513 struct consumer_socket *socket;
2514 struct lttng_ht_iter iter;
2515 int ret;
2516 char *path = NULL;
2517
2518 if (!output || !output->socks) {
2519 ERR("No consumer output found");
2520 ret = -1;
2521 goto end;
2522 }
2523
2524 path = zmalloc(LTTNG_PATH_MAX * sizeof(char));
2525 if (!path) {
2526 ERR("Cannot allocate mkdir path");
2527 ret = -1;
2528 goto end;
2529 }
2530
2531 ret = snprintf(path, LTTNG_PATH_MAX, "%s%s%s",
2532 session_get_base_path(session),
2533 output->chunk_path, output->subdir);
2534 if (ret < 0 || ret >= LTTNG_PATH_MAX) {
2535 ERR("Format path");
2536 ret = -1;
2537 goto end;
2538 }
2539
2540 DBG("Domain mkdir %s for session %" PRIu64, path, session->id);
2541 rcu_read_lock();
2542 /*
2543 * We have to iterate to find a socket, but we only need to send the
2544 * rename command to one consumer, so we break after the first one.
2545 */
2546 cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
2547 pthread_mutex_lock(socket->lock);
2548 ret = consumer_mkdir(socket, session->id, output, path, uid, gid);
2549 pthread_mutex_unlock(socket->lock);
2550 if (ret) {
2551 ERR("Consumer mkdir");
2552 ret = -1;
2553 goto end_unlock;
2554 }
2555 break;
2556 }
2557
2558 ret = 0;
2559
2560 end_unlock:
2561 rcu_read_unlock();
2562 end:
2563 free(path);
2564 return ret;
2565 }
2566
2567 static
2568 int session_mkdir(const struct ltt_session *session)
2569 {
2570 int ret;
2571 struct consumer_output *output;
2572 uid_t uid;
2573 gid_t gid;
2574
2575 /*
2576 * Unsupported feature in lttng-relayd before 2.11, not an error since it
2577 * is only needed for session rotation and the user will get an error
2578 * on rotate.
2579 */
2580 if (session->consumer->type == CONSUMER_DST_NET &&
2581 session->consumer->relay_major_version == 2 &&
2582 session->consumer->relay_minor_version < 11) {
2583 ret = 0;
2584 goto end;
2585 }
2586
2587 if (session->kernel_session) {
2588 output = session->kernel_session->consumer;
2589 uid = session->kernel_session->uid;
2590 gid = session->kernel_session->gid;
2591 ret = domain_mkdir(output, session, uid, gid);
2592 if (ret) {
2593 ERR("Mkdir kernel");
2594 goto end;
2595 }
2596 }
2597
2598 if (session->ust_session) {
2599 output = session->ust_session->consumer;
2600 uid = session->ust_session->uid;
2601 gid = session->ust_session->gid;
2602 ret = domain_mkdir(output, session, uid, gid);
2603 if (ret) {
2604 ERR("Mkdir UST");
2605 goto end;
2606 }
2607 }
2608
2609 ret = 0;
2610
2611 end:
2612 return ret;
2613 }
2614
2615 /*
2616 * Command LTTNG_START_TRACE processed by the client thread.
2617 *
2618 * Called with session mutex held.
2619 */
2620 int cmd_start_trace(struct ltt_session *session)
2621 {
2622 int ret;
2623 unsigned long nb_chan = 0;
2624 struct ltt_kernel_session *ksession;
2625 struct ltt_ust_session *usess;
2626
2627 assert(session);
2628
2629 /* Ease our life a bit ;) */
2630 ksession = session->kernel_session;
2631 usess = session->ust_session;
2632
2633 /* Is the session already started? */
2634 if (session->active) {
2635 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2636 goto error;
2637 }
2638
2639 /*
2640 * Starting a session without channel is useless since after that it's not
2641 * possible to enable channel thus inform the client.
2642 */
2643 if (usess && usess->domain_global.channels) {
2644 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2645 }
2646 if (ksession) {
2647 nb_chan += ksession->channel_count;
2648 }
2649 if (!nb_chan) {
2650 ret = LTTNG_ERR_NO_CHANNEL;
2651 goto error;
2652 }
2653
2654 /*
2655 * Record the timestamp of the first time the session is started for
2656 * an eventual session rotation call.
2657 */
2658 if (!session->has_been_started) {
2659 session->current_chunk_start_ts = time(NULL);
2660 if (session->current_chunk_start_ts == (time_t) -1) {
2661 PERROR("Failed to retrieve the \"%s\" session's start time",
2662 session->name);
2663 ret = LTTNG_ERR_FATAL;
2664 goto error;
2665 }
2666 if (!session->snapshot_mode && session->output_traces) {
2667 ret = session_mkdir(session);
2668 if (ret) {
2669 ERR("Failed to create the session directories");
2670 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2671 goto error;
2672 }
2673 }
2674 }
2675
2676 /* Kernel tracing */
2677 if (ksession != NULL) {
2678 DBG("Start kernel tracing session %s", session->name);
2679 ret = start_kernel_session(ksession, kernel_tracer_fd);
2680 if (ret != LTTNG_OK) {
2681 goto error;
2682 }
2683 }
2684
2685 /* Flag session that trace should start automatically */
2686 if (usess) {
2687 /*
2688 * Even though the start trace might fail, flag this session active so
2689 * other application coming in are started by default.
2690 */
2691 usess->active = 1;
2692
2693 ret = ust_app_start_trace_all(usess);
2694 if (ret < 0) {
2695 ret = LTTNG_ERR_UST_START_FAIL;
2696 goto error;
2697 }
2698 }
2699
2700 /* Flag this after a successful start. */
2701 session->has_been_started = 1;
2702 session->active = 1;
2703
2704 /*
2705 * Clear the flag that indicates that a rotation was done while the
2706 * session was stopped.
2707 */
2708 session->rotated_after_last_stop = false;
2709
2710 if (session->rotate_timer_period) {
2711 ret = timer_session_rotation_schedule_timer_start(session,
2712 session->rotate_timer_period);
2713 if (ret < 0) {
2714 ERR("Failed to enable rotate timer");
2715 ret = LTTNG_ERR_UNK;
2716 goto error;
2717 }
2718 }
2719
2720 ret = LTTNG_OK;
2721
2722 error:
2723 return ret;
2724 }
2725
2726 /*
2727 * Command LTTNG_STOP_TRACE processed by the client thread.
2728 */
2729 int cmd_stop_trace(struct ltt_session *session)
2730 {
2731 int ret;
2732 struct ltt_kernel_channel *kchan;
2733 struct ltt_kernel_session *ksession;
2734 struct ltt_ust_session *usess;
2735 bool error_occurred = false;
2736
2737 assert(session);
2738
2739 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2740 /* Short cut */
2741 ksession = session->kernel_session;
2742 usess = session->ust_session;
2743
2744 /* Session is not active. Skip everythong and inform the client. */
2745 if (!session->active) {
2746 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2747 goto error;
2748 }
2749
2750 if (session->rotation_schedule_timer_enabled) {
2751 if (timer_session_rotation_schedule_timer_stop(
2752 session)) {
2753 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
2754 session->name);
2755 }
2756 }
2757
2758 /*
2759 * A rotation is still ongoing. The check timer will continue to wait
2760 * for the rotation to complete. When the rotation finally completes,
2761 * a check will be performed to rename the "active" chunk to the
2762 * expected "timestamp_begin-timestamp_end" format.
2763 */
2764 if (session->current_archive_id > 0 &&
2765 session->rotation_state != LTTNG_ROTATION_STATE_ONGOING) {
2766 ret = rename_active_chunk(session);
2767 if (ret) {
2768 /*
2769 * This error should not prevent the user from stopping
2770 * the session. However, it will be reported at the end.
2771 */
2772 error_occurred = true;
2773 }
2774 }
2775
2776 /* Kernel tracer */
2777 if (ksession && ksession->active) {
2778 DBG("Stop kernel tracing");
2779
2780 ret = kernel_stop_session(ksession);
2781 if (ret < 0) {
2782 ret = LTTNG_ERR_KERN_STOP_FAIL;
2783 goto error;
2784 }
2785
2786 kernel_wait_quiescent(kernel_tracer_fd);
2787
2788 /* Flush metadata after stopping (if exists) */
2789 if (ksession->metadata_stream_fd >= 0) {
2790 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2791 if (ret < 0) {
2792 ERR("Kernel metadata flush failed");
2793 }
2794 }
2795
2796 /* Flush all buffers after stopping */
2797 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2798 ret = kernel_flush_buffer(kchan);
2799 if (ret < 0) {
2800 ERR("Kernel flush buffer error");
2801 }
2802 }
2803
2804 ksession->active = 0;
2805 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2806 session->id);
2807 }
2808
2809 if (usess && usess->active) {
2810 /*
2811 * Even though the stop trace might fail, flag this session inactive so
2812 * other application coming in are not started by default.
2813 */
2814 usess->active = 0;
2815
2816 ret = ust_app_stop_trace_all(usess);
2817 if (ret < 0) {
2818 ret = LTTNG_ERR_UST_STOP_FAIL;
2819 goto error;
2820 }
2821 }
2822
2823 /* Flag inactive after a successful stop. */
2824 session->active = 0;
2825 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2826
2827 error:
2828 return ret;
2829 }
2830
2831 /*
2832 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2833 */
2834 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2835 struct lttng_uri *uris)
2836 {
2837 int ret, i;
2838 struct ltt_kernel_session *ksess = session->kernel_session;
2839 struct ltt_ust_session *usess = session->ust_session;
2840
2841 assert(session);
2842 assert(uris);
2843 assert(nb_uri > 0);
2844
2845 /* Can't set consumer URI if the session is active. */
2846 if (session->active) {
2847 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2848 goto error;
2849 }
2850
2851 /* Set the "global" consumer URIs */
2852 for (i = 0; i < nb_uri; i++) {
2853 ret = add_uri_to_consumer(session->consumer,
2854 &uris[i], 0, session->name);
2855 if (ret != LTTNG_OK) {
2856 goto error;
2857 }
2858 }
2859
2860 /* Set UST session URIs */
2861 if (session->ust_session) {
2862 for (i = 0; i < nb_uri; i++) {
2863 ret = add_uri_to_consumer(
2864 session->ust_session->consumer,
2865 &uris[i], LTTNG_DOMAIN_UST,
2866 session->name);
2867 if (ret != LTTNG_OK) {
2868 goto error;
2869 }
2870 }
2871 }
2872
2873 /* Set kernel session URIs */
2874 if (session->kernel_session) {
2875 for (i = 0; i < nb_uri; i++) {
2876 ret = add_uri_to_consumer(
2877 session->kernel_session->consumer,
2878 &uris[i], LTTNG_DOMAIN_KERNEL,
2879 session->name);
2880 if (ret != LTTNG_OK) {
2881 goto error;
2882 }
2883 }
2884 }
2885
2886 /*
2887 * Make sure to set the session in output mode after we set URI since a
2888 * session can be created without URL (thus flagged in no output mode).
2889 */
2890 session->output_traces = 1;
2891 if (ksess) {
2892 ksess->output_traces = 1;
2893 }
2894
2895 if (usess) {
2896 usess->output_traces = 1;
2897 }
2898
2899 /* All good! */
2900 ret = LTTNG_OK;
2901
2902 error:
2903 return ret;
2904 }
2905
2906 /*
2907 * Command LTTNG_CREATE_SESSION processed by the client thread.
2908 */
2909 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
2910 size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
2911 {
2912 int ret;
2913 struct ltt_session *session = NULL;
2914
2915 assert(name);
2916 assert(creds);
2917
2918 /* Check if the session already exists. */
2919 session_lock_list();
2920 session = session_find_by_name(name);
2921 session_unlock_list();
2922 if (session != NULL) {
2923 ret = LTTNG_ERR_EXIST_SESS;
2924 goto end;
2925 }
2926
2927 /* Create tracing session in the registry */
2928 ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
2929 LTTNG_SOCK_GET_GID_CRED(creds));
2930 if (ret != LTTNG_OK) {
2931 goto end;
2932 }
2933
2934 /* Get the newly created session pointer back. */
2935 session_lock_list();
2936 session = session_find_by_name(name);
2937 session_unlock_list();
2938 assert(session);
2939
2940 session->live_timer = live_timer;
2941 /* Create default consumer output for the session not yet created. */
2942 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
2943 if (session->consumer == NULL) {
2944 ret = LTTNG_ERR_FATAL;
2945 goto end;
2946 }
2947
2948 if (uris) {
2949 ret = cmd_set_consumer_uri(session, nb_uri, uris);
2950 if (ret != LTTNG_OK) {
2951 goto end;
2952 }
2953 session->output_traces = 1;
2954 } else {
2955 session->output_traces = 0;
2956 DBG2("Session %s created with no output", session->name);
2957 }
2958
2959 session->consumer->enabled = 1;
2960
2961 ret = LTTNG_OK;
2962 end:
2963 if (session) {
2964 session_lock_list();
2965 session_put(session);
2966 session_unlock_list();
2967 }
2968 return ret;
2969 }
2970
2971 /*
2972 * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
2973 */
2974 int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
2975 size_t nb_uri, lttng_sock_cred *creds)
2976 {
2977 int ret;
2978 struct ltt_session *session = NULL;
2979 struct snapshot_output *new_output = NULL;
2980
2981 assert(name);
2982 assert(creds);
2983
2984 /*
2985 * Create session in no output mode with URIs set to NULL. The uris we've
2986 * received are for a default snapshot output if one.
2987 */
2988 ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
2989 if (ret != LTTNG_OK) {
2990 goto end;
2991 }
2992
2993 /* Get the newly created session pointer back. This should NEVER fail. */
2994 session_lock_list();
2995 session = session_find_by_name(name);
2996 session_unlock_list();
2997 assert(session);
2998
2999 /* Flag session for snapshot mode. */
3000 session->snapshot_mode = 1;
3001
3002 /* Skip snapshot output creation if no URI is given. */
3003 if (nb_uri == 0) {
3004 /* Not an error. */
3005 goto end;
3006 }
3007
3008 new_output = snapshot_output_alloc();
3009 if (!new_output) {
3010 ret = LTTNG_ERR_NOMEM;
3011 goto error_snapshot_alloc;
3012 }
3013
3014 ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
3015 uris, nb_uri, session->consumer, new_output, &session->snapshot);
3016 if (ret < 0) {
3017 if (ret == -ENOMEM) {
3018 ret = LTTNG_ERR_NOMEM;
3019 } else {
3020 ret = LTTNG_ERR_INVALID;
3021 }
3022 goto error_snapshot;
3023 }
3024
3025 rcu_read_lock();
3026 snapshot_add_output(&session->snapshot, new_output);
3027 rcu_read_unlock();
3028
3029 ret = LTTNG_OK;
3030 goto end;
3031
3032 error_snapshot:
3033 snapshot_output_destroy(new_output);
3034 error_snapshot_alloc:
3035 end:
3036 if (session) {
3037 session_lock_list();
3038 session_put(session);
3039 session_unlock_list();
3040 }
3041 return ret;
3042 }
3043
3044 /*
3045 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3046 *
3047 * Called with session lock held.
3048 */
3049 int cmd_destroy_session(struct ltt_session *session,
3050 struct notification_thread_handle *notification_thread_handle)
3051 {
3052 int ret;
3053
3054 /* Safety net */
3055 assert(session);
3056
3057 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
3058
3059 if (session->rotation_pending_check_timer_enabled) {
3060 if (timer_session_rotation_pending_check_stop(session)) {
3061 ERR("Failed to stop the \"rotation pending check\" timer of session %s",
3062 session->name);
3063 }
3064 }
3065
3066 if (session->rotation_schedule_timer_enabled) {
3067 if (timer_session_rotation_schedule_timer_stop(
3068 session)) {
3069 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3070 session->name);
3071 }
3072 }
3073
3074 if (session->rotate_size) {
3075 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3076 session->rotate_size = 0;
3077 }
3078
3079 /*
3080 * The rename of the current chunk is performed at stop, but if we rotated
3081 * the session after the previous stop command, we need to rename the
3082 * new (and empty) chunk that was started in between.
3083 */
3084 if (session->rotated_after_last_stop) {
3085 rename_active_chunk(session);
3086 }
3087
3088 if (session->shm_path[0]) {
3089 /*
3090 * When a session is created with an explicit shm_path,
3091 * the consumer daemon will create its shared memory files
3092 * at that location and will *not* unlink them. This is normal
3093 * as the intention of that feature is to make it possible
3094 * to retrieve the content of those files should a crash occur.
3095 *
3096 * To ensure the content of those files can be used, the
3097 * sessiond daemon will replicate the content of the metadata
3098 * cache in a metadata file.
3099 *
3100 * On clean-up, it is expected that the consumer daemon will
3101 * unlink the shared memory files and that the session daemon
3102 * will unlink the metadata file. Then, the session's directory
3103 * in the shm path can be removed.
3104 *
3105 * Unfortunately, a flaw in the design of the sessiond's and
3106 * consumerd's tear down of channels makes it impossible to
3107 * determine when the sessiond _and_ the consumerd have both
3108 * destroyed their representation of a channel. For one, the
3109 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3110 * callbacks in both daemons.
3111 *
3112 * However, it is also impossible for the sessiond to know when
3113 * the consumer daemon is done destroying its channel(s) since
3114 * it occurs as a reaction to the closing of the channel's file
3115 * descriptor. There is no resulting communication initiated
3116 * from the consumerd to the sessiond to confirm that the
3117 * operation is completed (and was successful).
3118 *
3119 * Until this is all fixed, the session daemon checks for the
3120 * removal of the session's shm path which makes it possible
3121 * to safely advertise a session as having been destroyed.
3122 *
3123 * Prior to this fix, it was not possible to reliably save
3124 * a session making use of the --shm-path option, destroy it,
3125 * and load it again. This is because the creation of the
3126 * session would fail upon seeing the session's shm path
3127 * already in existence.
3128 *
3129 * Note that none of the error paths in the check for the
3130 * directory's existence return an error. This is normal
3131 * as there isn't much that can be done. The session will
3132 * be destroyed properly, except that we can't offer the
3133 * guarantee that the same session can be re-created.
3134 */
3135 current_completion_handler = &destroy_completion_handler.handler;
3136 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3137 session->shm_path,
3138 sizeof(destroy_completion_handler.shm_path));
3139 assert(!ret);
3140 }
3141
3142 /*
3143 * The session is destroyed. However, note that the command context
3144 * still holds a reference to the session, thus delaying its destruction
3145 * _at least_ up to the point when that reference is released.
3146 */
3147 session_destroy(session);
3148 ret = LTTNG_OK;
3149
3150 return ret;
3151 }
3152
3153 /*
3154 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3155 */
3156 int cmd_register_consumer(struct ltt_session *session,
3157 enum lttng_domain_type domain, const char *sock_path,
3158 struct consumer_data *cdata)
3159 {
3160 int ret, sock;
3161 struct consumer_socket *socket = NULL;
3162
3163 assert(session);
3164 assert(cdata);
3165 assert(sock_path);
3166
3167 switch (domain) {
3168 case LTTNG_DOMAIN_KERNEL:
3169 {
3170 struct ltt_kernel_session *ksess = session->kernel_session;
3171
3172 assert(ksess);
3173
3174 /* Can't register a consumer if there is already one */
3175 if (ksess->consumer_fds_sent != 0) {
3176 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3177 goto error;
3178 }
3179
3180 sock = lttcomm_connect_unix_sock(sock_path);
3181 if (sock < 0) {
3182 ret = LTTNG_ERR_CONNECT_FAIL;
3183 goto error;
3184 }
3185 cdata->cmd_sock = sock;
3186
3187 socket = consumer_allocate_socket(&cdata->cmd_sock);
3188 if (socket == NULL) {
3189 ret = close(sock);
3190 if (ret < 0) {
3191 PERROR("close register consumer");
3192 }
3193 cdata->cmd_sock = -1;
3194 ret = LTTNG_ERR_FATAL;
3195 goto error;
3196 }
3197
3198 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3199 if (socket->lock == NULL) {
3200 PERROR("zmalloc pthread mutex");
3201 ret = LTTNG_ERR_FATAL;
3202 goto error;
3203 }
3204 pthread_mutex_init(socket->lock, NULL);
3205 socket->registered = 1;
3206
3207 rcu_read_lock();
3208 consumer_add_socket(socket, ksess->consumer);
3209 rcu_read_unlock();
3210
3211 pthread_mutex_lock(&cdata->pid_mutex);
3212 cdata->pid = -1;
3213 pthread_mutex_unlock(&cdata->pid_mutex);
3214
3215 break;
3216 }
3217 default:
3218 /* TODO: Userspace tracing */
3219 ret = LTTNG_ERR_UND;
3220 goto error;
3221 }
3222
3223 return LTTNG_OK;
3224
3225 error:
3226 if (socket) {
3227 consumer_destroy_socket(socket);
3228 }
3229 return ret;
3230 }
3231
3232 /*
3233 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3234 */
3235 ssize_t cmd_list_domains(struct ltt_session *session,
3236 struct lttng_domain **domains)
3237 {
3238 int ret, index = 0;
3239 ssize_t nb_dom = 0;
3240 struct agent *agt;
3241 struct lttng_ht_iter iter;
3242
3243 if (session->kernel_session != NULL) {
3244 DBG3("Listing domains found kernel domain");
3245 nb_dom++;
3246 }
3247
3248 if (session->ust_session != NULL) {
3249 DBG3("Listing domains found UST global domain");
3250 nb_dom++;
3251
3252 rcu_read_lock();
3253 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3254 agt, node.node) {
3255 if (agt->being_used) {
3256 nb_dom++;
3257 }
3258 }
3259 rcu_read_unlock();
3260 }
3261
3262 if (!nb_dom) {
3263 goto end;
3264 }
3265
3266 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3267 if (*domains == NULL) {
3268 ret = LTTNG_ERR_FATAL;
3269 goto error;
3270 }
3271
3272 if (session->kernel_session != NULL) {
3273 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3274
3275 /* Kernel session buffer type is always GLOBAL */
3276 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3277
3278 index++;
3279 }
3280
3281 if (session->ust_session != NULL) {
3282 (*domains)[index].type = LTTNG_DOMAIN_UST;
3283 (*domains)[index].buf_type = session->ust_session->buffer_type;
3284 index++;
3285
3286 rcu_read_lock();
3287 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3288 agt, node.node) {
3289 if (agt->being_used) {
3290 (*domains)[index].type = agt->domain;
3291 (*domains)[index].buf_type = session->ust_session->buffer_type;
3292 index++;
3293 }
3294 }
3295 rcu_read_unlock();
3296 }
3297 end:
3298 return nb_dom;
3299
3300 error:
3301 /* Return negative value to differentiate return code */
3302 return -ret;
3303 }
3304
3305
3306 /*
3307 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3308 */
3309 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3310 struct ltt_session *session, struct lttng_channel **channels)
3311 {
3312 ssize_t nb_chan = 0, payload_size = 0, ret;
3313
3314 switch (domain) {
3315 case LTTNG_DOMAIN_KERNEL:
3316 if (session->kernel_session != NULL) {
3317 nb_chan = session->kernel_session->channel_count;
3318 }
3319 DBG3("Number of kernel channels %zd", nb_chan);
3320 if (nb_chan <= 0) {
3321 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3322 goto end;
3323 }
3324 break;
3325 case LTTNG_DOMAIN_UST:
3326 if (session->ust_session != NULL) {
3327 rcu_read_lock();
3328 nb_chan = lttng_ht_get_count(
3329 session->ust_session->domain_global.channels);
3330 rcu_read_unlock();
3331 }
3332 DBG3("Number of UST global channels %zd", nb_chan);
3333 if (nb_chan < 0) {
3334 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3335 goto end;
3336 }
3337 break;
3338 default:
3339 ret = -LTTNG_ERR_UND;
3340 goto end;
3341 }
3342
3343 if (nb_chan > 0) {
3344 const size_t channel_size = sizeof(struct lttng_channel) +
3345 sizeof(struct lttng_channel_extended);
3346 struct lttng_channel_extended *channel_exts;
3347
3348 payload_size = nb_chan * channel_size;
3349 *channels = zmalloc(payload_size);
3350 if (*channels == NULL) {
3351 ret = -LTTNG_ERR_FATAL;
3352 goto end;
3353 }
3354
3355 channel_exts = ((void *) *channels) +
3356 (nb_chan * sizeof(struct lttng_channel));
3357 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3358 if (ret != LTTNG_OK) {
3359 free(*channels);
3360 *channels = NULL;
3361 goto end;
3362 }
3363 } else {
3364 *channels = NULL;
3365 }
3366
3367 ret = payload_size;
3368 end:
3369 return ret;
3370 }
3371
3372 /*
3373 * Command LTTNG_LIST_EVENTS processed by the client thread.
3374 */
3375 ssize_t cmd_list_events(enum lttng_domain_type domain,
3376 struct ltt_session *session, char *channel_name,
3377 struct lttng_event **events, size_t *total_size)
3378 {
3379 int ret = 0;
3380 ssize_t nb_event = 0;
3381
3382 switch (domain) {
3383 case LTTNG_DOMAIN_KERNEL:
3384 if (session->kernel_session != NULL) {
3385 nb_event = list_lttng_kernel_events(channel_name,
3386 session->kernel_session, events,
3387 total_size);
3388 }
3389 break;
3390 case LTTNG_DOMAIN_UST:
3391 {
3392 if (session->ust_session != NULL) {
3393 nb_event = list_lttng_ust_global_events(channel_name,
3394 &session->ust_session->domain_global, events,
3395 total_size);
3396 }
3397 break;
3398 }
3399 case LTTNG_DOMAIN_LOG4J:
3400 case LTTNG_DOMAIN_JUL:
3401 case LTTNG_DOMAIN_PYTHON:
3402 if (session->ust_session) {
3403 struct lttng_ht_iter iter;
3404 struct agent *agt;
3405
3406 rcu_read_lock();
3407 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3408 &iter.iter, agt, node.node) {
3409 if (agt->domain == domain) {
3410 nb_event = list_lttng_agent_events(
3411 agt, events,
3412 total_size);
3413 break;
3414 }
3415 }
3416 rcu_read_unlock();
3417 }
3418 break;
3419 default:
3420 ret = LTTNG_ERR_UND;
3421 goto error;
3422 }
3423
3424 return nb_event;
3425
3426 error:
3427 /* Return negative value to differentiate return code */
3428 return -ret;
3429 }
3430
3431 /*
3432 * Using the session list, filled a lttng_session array to send back to the
3433 * client for session listing.
3434 *
3435 * The session list lock MUST be acquired before calling this function. Use
3436 * session_lock_list() and session_unlock_list().
3437 */
3438 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
3439 gid_t gid)
3440 {
3441 int ret;
3442 unsigned int i = 0;
3443 struct ltt_session *session;
3444 struct ltt_session_list *list = session_get_list();
3445
3446 DBG("Getting all available session for UID %d GID %d",
3447 uid, gid);
3448 /*
3449 * Iterate over session list and append data after the control struct in
3450 * the buffer.
3451 */
3452 cds_list_for_each_entry(session, &list->head, list) {
3453 if (!session_get(session)) {
3454 continue;
3455 }
3456 /*
3457 * Only list the sessions the user can control.
3458 */
3459 if (!session_access_ok(session, uid, gid) ||
3460 session->destroyed) {
3461 session_put(session);
3462 continue;
3463 }
3464
3465 struct ltt_kernel_session *ksess = session->kernel_session;
3466 struct ltt_ust_session *usess = session->ust_session;
3467
3468 if (session->consumer->type == CONSUMER_DST_NET ||
3469 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3470 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3471 ret = build_network_session_path(sessions[i].path,
3472 sizeof(sessions[i].path), session);
3473 } else {
3474 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3475 session->consumer->dst.session_root_path);
3476 }
3477 if (ret < 0) {
3478 PERROR("snprintf session path");
3479 session_put(session);
3480 continue;
3481 }
3482
3483 strncpy(sessions[i].name, session->name, NAME_MAX);
3484 sessions[i].name[NAME_MAX - 1] = '\0';
3485 sessions[i].enabled = session->active;
3486 sessions[i].snapshot_mode = session->snapshot_mode;
3487 sessions[i].live_timer_interval = session->live_timer;
3488 i++;
3489 session_put(session);
3490 }
3491 }
3492
3493 /*
3494 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3495 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3496 */
3497 int cmd_data_pending(struct ltt_session *session)
3498 {
3499 int ret;
3500 struct ltt_kernel_session *ksess = session->kernel_session;
3501 struct ltt_ust_session *usess = session->ust_session;
3502
3503 assert(session);
3504
3505 DBG("Data pending for session %s", session->name);
3506
3507 /* Session MUST be stopped to ask for data availability. */
3508 if (session->active) {
3509 ret = LTTNG_ERR_SESSION_STARTED;
3510 goto error;
3511 } else {
3512 /*
3513 * If stopped, just make sure we've started before else the above call
3514 * will always send that there is data pending.
3515 *
3516 * The consumer assumes that when the data pending command is received,
3517 * the trace has been started before or else no output data is written
3518 * by the streams which is a condition for data pending. So, this is
3519 * *VERY* important that we don't ask the consumer before a start
3520 * trace.
3521 */
3522 if (!session->has_been_started) {
3523 ret = 0;
3524 goto error;
3525 }
3526 }
3527
3528 /* A rotation is still pending, we have to wait. */
3529 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3530 DBG("Rotate still pending for session %s", session->name);
3531 ret = 1;
3532 goto error;
3533 }
3534
3535 if (ksess && ksess->consumer) {
3536 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3537 if (ret == 1) {
3538 /* Data is still being extracted for the kernel. */
3539 goto error;
3540 }
3541 }
3542
3543 if (usess && usess->consumer) {
3544 ret = consumer_is_data_pending(usess->id, usess->consumer);
3545 if (ret == 1) {
3546 /* Data is still being extracted for the kernel. */
3547 goto error;
3548 }
3549 }
3550
3551 /* Data is ready to be read by a viewer */
3552 ret = 0;
3553
3554 error:
3555 return ret;
3556 }
3557
3558 /*
3559 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3560 *
3561 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3562 */
3563 int cmd_snapshot_add_output(struct ltt_session *session,
3564 struct lttng_snapshot_output *output, uint32_t *id)
3565 {
3566 int ret;
3567 struct snapshot_output *new_output;
3568
3569 assert(session);
3570 assert(output);
3571
3572 DBG("Cmd snapshot add output for session %s", session->name);
3573
3574 /*
3575 * Can't create an output if the session is not set in no-output mode.
3576 */
3577 if (session->output_traces) {
3578 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3579 goto error;
3580 }
3581
3582 /* Only one output is allowed until we have the "tee" feature. */
3583 if (session->snapshot.nb_output == 1) {
3584 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3585 goto error;
3586 }
3587
3588 new_output = snapshot_output_alloc();
3589 if (!new_output) {
3590 ret = LTTNG_ERR_NOMEM;
3591 goto error;
3592 }
3593
3594 ret = snapshot_output_init(output->max_size, output->name,
3595 output->ctrl_url, output->data_url, session->consumer, new_output,
3596 &session->snapshot);
3597 if (ret < 0) {
3598 if (ret == -ENOMEM) {
3599 ret = LTTNG_ERR_NOMEM;
3600 } else {
3601 ret = LTTNG_ERR_INVALID;
3602 }
3603 goto free_error;
3604 }
3605
3606 rcu_read_lock();
3607 snapshot_add_output(&session->snapshot, new_output);
3608 if (id) {
3609 *id = new_output->id;
3610 }
3611 rcu_read_unlock();
3612
3613 return LTTNG_OK;
3614
3615 free_error:
3616 snapshot_output_destroy(new_output);
3617 error:
3618 return ret;
3619 }
3620
3621 /*
3622 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3623 *
3624 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3625 */
3626 int cmd_snapshot_del_output(struct ltt_session *session,
3627 struct lttng_snapshot_output *output)
3628 {
3629 int ret;
3630 struct snapshot_output *sout = NULL;
3631
3632 assert(session);
3633 assert(output);
3634
3635 rcu_read_lock();
3636
3637 /*
3638 * Permission denied to create an output if the session is not
3639 * set in no output mode.
3640 */
3641 if (session->output_traces) {
3642 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3643 goto error;
3644 }
3645
3646 if (output->id) {
3647 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3648 session->name);
3649 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3650 } else if (*output->name != '\0') {
3651 DBG("Cmd snapshot del output name %s for session %s", output->name,
3652 session->name);
3653 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3654 }
3655 if (!sout) {
3656 ret = LTTNG_ERR_INVALID;
3657 goto error;
3658 }
3659
3660 snapshot_delete_output(&session->snapshot, sout);
3661 snapshot_output_destroy(sout);
3662 ret = LTTNG_OK;
3663
3664 error:
3665 rcu_read_unlock();
3666 return ret;
3667 }
3668
3669 /*
3670 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3671 *
3672 * If no output is available, outputs is untouched and 0 is returned.
3673 *
3674 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3675 */
3676 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3677 struct lttng_snapshot_output **outputs)
3678 {
3679 int ret, idx = 0;
3680 struct lttng_snapshot_output *list = NULL;
3681 struct lttng_ht_iter iter;
3682 struct snapshot_output *output;
3683
3684 assert(session);
3685 assert(outputs);
3686
3687 DBG("Cmd snapshot list outputs for session %s", session->name);
3688
3689 /*
3690 * Permission denied to create an output if the session is not
3691 * set in no output mode.
3692 */
3693 if (session->output_traces) {
3694 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3695 goto end;
3696 }
3697
3698 if (session->snapshot.nb_output == 0) {
3699 ret = 0;
3700 goto end;
3701 }
3702
3703 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3704 if (!list) {
3705 ret = -LTTNG_ERR_NOMEM;
3706 goto end;
3707 }
3708
3709 /* Copy list from session to the new list object. */
3710 rcu_read_lock();
3711 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3712 output, node.node) {
3713 assert(output->consumer);
3714 list[idx].id = output->id;
3715 list[idx].max_size = output->max_size;
3716 if (lttng_strncpy(list[idx].name, output->name,
3717 sizeof(list[idx].name))) {
3718 ret = -LTTNG_ERR_INVALID;
3719 goto error;
3720 }
3721 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3722 if (lttng_strncpy(list[idx].ctrl_url,
3723 output->consumer->dst.session_root_path,
3724 sizeof(list[idx].ctrl_url))) {
3725 ret = -LTTNG_ERR_INVALID;
3726 goto error;
3727 }
3728 } else {
3729 /* Control URI. */
3730 ret = uri_to_str_url(&output->consumer->dst.net.control,
3731 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3732 if (ret < 0) {
3733 ret = -LTTNG_ERR_NOMEM;
3734 goto error;
3735 }
3736
3737 /* Data URI. */
3738 ret = uri_to_str_url(&output->consumer->dst.net.data,
3739 list[idx].data_url, sizeof(list[idx].data_url));
3740 if (ret < 0) {
3741 ret = -LTTNG_ERR_NOMEM;
3742 goto error;
3743 }
3744 }
3745 idx++;
3746 }
3747
3748 *outputs = list;
3749 list = NULL;
3750 ret = session->snapshot.nb_output;
3751 error:
3752 rcu_read_unlock();
3753 free(list);
3754 end:
3755 return ret;
3756 }
3757
3758 /*
3759 * Check if we can regenerate the metadata for this session.
3760 * Only kernel, UST per-uid and non-live sessions are supported.
3761 *
3762 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3763 */
3764 static
3765 int check_regenerate_metadata_support(struct ltt_session *session)
3766 {
3767 int ret;
3768
3769 assert(session);
3770
3771 if (session->live_timer != 0) {
3772 ret = LTTNG_ERR_LIVE_SESSION;
3773 goto end;
3774 }
3775 if (!session->active) {
3776 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3777 goto end;
3778 }
3779 if (session->ust_session) {
3780 switch (session->ust_session->buffer_type) {
3781 case LTTNG_BUFFER_PER_UID:
3782 break;
3783 case LTTNG_BUFFER_PER_PID:
3784 ret = LTTNG_ERR_PER_PID_SESSION;
3785 goto end;
3786 default:
3787 assert(0);
3788 ret