e0a8db9b2cc13a2b5c77407e0b14938fa565a587
[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
25 #include <common/defaults.h>
26 #include <common/common.h>
27 #include <common/sessiond-comm/sessiond-comm.h>
28 #include <common/relayd/relayd.h>
29 #include <common/utils.h>
30 #include <common/compat/string.h>
31 #include <common/kernel-ctl/kernel-ctl.h>
32 #include <common/dynamic-buffer.h>
33 #include <common/buffer-view.h>
34 #include <lttng/trigger/trigger-internal.h>
35 #include <lttng/condition/condition.h>
36 #include <lttng/action/action.h>
37 #include <lttng/channel.h>
38 #include <lttng/channel-internal.h>
39 #include <lttng/rotate-internal.h>
40 #include <common/string-utils/string-utils.h>
41
42 #include "channel.h"
43 #include "consumer.h"
44 #include "event.h"
45 #include "health-sessiond.h"
46 #include "kernel.h"
47 #include "kernel-consumer.h"
48 #include "lttng-sessiond.h"
49 #include "utils.h"
50 #include "syscall.h"
51 #include "agent.h"
52 #include "buffer-registry.h"
53 #include "notification-thread.h"
54 #include "notification-thread-commands.h"
55 #include "rotate.h"
56 #include "rotation-thread.h"
57 #include "sessiond-timer.h"
58
59 #include "cmd.h"
60
61 /*
62 * Used to keep a unique index for each relayd socket created where this value
63 * is associated with streams on the consumer so it can match the right relayd
64 * to send to. It must be accessed with the relayd_net_seq_idx_lock
65 * held.
66 */
67 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
68 static uint64_t relayd_net_seq_idx;
69
70 static int validate_ust_event_name(const char *);
71 static int cmd_enable_event_internal(struct ltt_session *session,
72 struct lttng_domain *domain,
73 char *channel_name, struct lttng_event *event,
74 char *filter_expression,
75 struct lttng_filter_bytecode *filter,
76 struct lttng_event_exclusion *exclusion,
77 int wpipe);
78
79 /*
80 * Create a session path used by list_lttng_sessions for the case that the
81 * session consumer is on the network.
82 */
83 static int build_network_session_path(char *dst, size_t size,
84 struct ltt_session *session)
85 {
86 int ret, kdata_port, udata_port;
87 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
88 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
89
90 assert(session);
91 assert(dst);
92
93 memset(tmp_urls, 0, sizeof(tmp_urls));
94 memset(tmp_uurl, 0, sizeof(tmp_uurl));
95
96 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
97
98 if (session->kernel_session && session->kernel_session->consumer) {
99 kuri = &session->kernel_session->consumer->dst.net.control;
100 kdata_port = session->kernel_session->consumer->dst.net.data.port;
101 }
102
103 if (session->ust_session && session->ust_session->consumer) {
104 uuri = &session->ust_session->consumer->dst.net.control;
105 udata_port = session->ust_session->consumer->dst.net.data.port;
106 }
107
108 if (uuri == NULL && kuri == NULL) {
109 uri = &session->consumer->dst.net.control;
110 kdata_port = session->consumer->dst.net.data.port;
111 } else if (kuri && uuri) {
112 ret = uri_compare(kuri, uuri);
113 if (ret) {
114 /* Not Equal */
115 uri = kuri;
116 /* Build uuri URL string */
117 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
118 if (ret < 0) {
119 goto error;
120 }
121 } else {
122 uri = kuri;
123 }
124 } else if (kuri && uuri == NULL) {
125 uri = kuri;
126 } else if (uuri && kuri == NULL) {
127 uri = uuri;
128 }
129
130 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
131 if (ret < 0) {
132 goto error;
133 }
134
135 /*
136 * Do we have a UST url set. If yes, this means we have both kernel and UST
137 * to print.
138 */
139 if (*tmp_uurl != '\0') {
140 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
141 tmp_urls, kdata_port, tmp_uurl, udata_port);
142 } else {
143 int dport;
144 if (kuri || (!kuri && !uuri)) {
145 dport = kdata_port;
146 } else {
147 /* No kernel URI, use the UST port. */
148 dport = udata_port;
149 }
150 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
151 }
152
153 error:
154 return ret;
155 }
156
157 /*
158 * Get run-time attributes if the session has been started (discarded events,
159 * lost packets).
160 */
161 static int get_kernel_runtime_stats(struct ltt_session *session,
162 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
163 uint64_t *lost_packets)
164 {
165 int ret;
166
167 if (!session->has_been_started) {
168 ret = 0;
169 *discarded_events = 0;
170 *lost_packets = 0;
171 goto end;
172 }
173
174 ret = consumer_get_discarded_events(session->id, kchan->key,
175 session->kernel_session->consumer,
176 discarded_events);
177 if (ret < 0) {
178 goto end;
179 }
180
181 ret = consumer_get_lost_packets(session->id, kchan->key,
182 session->kernel_session->consumer,
183 lost_packets);
184 if (ret < 0) {
185 goto end;
186 }
187
188 end:
189 return ret;
190 }
191
192 /*
193 * Get run-time attributes if the session has been started (discarded events,
194 * lost packets).
195 */
196 static int get_ust_runtime_stats(struct ltt_session *session,
197 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
198 uint64_t *lost_packets)
199 {
200 int ret;
201 struct ltt_ust_session *usess;
202
203 if (!discarded_events || !lost_packets) {
204 ret = -1;
205 goto end;
206 }
207
208 usess = session->ust_session;
209 assert(discarded_events);
210 assert(lost_packets);
211
212 if (!usess || !session->has_been_started) {
213 *discarded_events = 0;
214 *lost_packets = 0;
215 ret = 0;
216 goto end;
217 }
218
219 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
220 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
221 &usess->buffer_reg_uid_list,
222 usess->consumer, uchan->id,
223 uchan->attr.overwrite,
224 discarded_events,
225 lost_packets);
226 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
227 ret = ust_app_pid_get_channel_runtime_stats(usess,
228 uchan, usess->consumer,
229 uchan->attr.overwrite,
230 discarded_events,
231 lost_packets);
232 if (ret < 0) {
233 goto end;
234 }
235 *discarded_events += uchan->per_pid_closed_app_discarded;
236 *lost_packets += uchan->per_pid_closed_app_lost;
237 } else {
238 ERR("Unsupported buffer type");
239 assert(0);
240 ret = -1;
241 goto end;
242 }
243
244 end:
245 return ret;
246 }
247
248 /*
249 * Fill lttng_channel array of all channels.
250 */
251 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
252 struct ltt_session *session, struct lttng_channel *channels,
253 struct lttng_channel_extended *chan_exts)
254 {
255 int i = 0, ret = 0;
256 struct ltt_kernel_channel *kchan;
257
258 DBG("Listing channels for session %s", session->name);
259
260 switch (domain) {
261 case LTTNG_DOMAIN_KERNEL:
262 /* Kernel channels */
263 if (session->kernel_session != NULL) {
264 cds_list_for_each_entry(kchan,
265 &session->kernel_session->channel_list.head, list) {
266 uint64_t discarded_events, lost_packets;
267 struct lttng_channel_extended *extended;
268
269 extended = (struct lttng_channel_extended *)
270 kchan->channel->attr.extended.ptr;
271
272 ret = get_kernel_runtime_stats(session, kchan,
273 &discarded_events, &lost_packets);
274 if (ret < 0) {
275 goto end;
276 }
277 /* Copy lttng_channel struct to array */
278 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
279 channels[i].enabled = kchan->enabled;
280 chan_exts[i].discarded_events =
281 discarded_events;
282 chan_exts[i].lost_packets = lost_packets;
283 chan_exts[i].monitor_timer_interval =
284 extended->monitor_timer_interval;
285 chan_exts[i].blocking_timeout = 0;
286 i++;
287 }
288 }
289 break;
290 case LTTNG_DOMAIN_UST:
291 {
292 struct lttng_ht_iter iter;
293 struct ltt_ust_channel *uchan;
294
295 rcu_read_lock();
296 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
297 &iter.iter, uchan, node.node) {
298 uint64_t discarded_events = 0, lost_packets = 0;
299
300 if (lttng_strncpy(channels[i].name, uchan->name,
301 LTTNG_SYMBOL_NAME_LEN)) {
302 break;
303 }
304 channels[i].attr.overwrite = uchan->attr.overwrite;
305 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
306 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
307 channels[i].attr.switch_timer_interval =
308 uchan->attr.switch_timer_interval;
309 channels[i].attr.read_timer_interval =
310 uchan->attr.read_timer_interval;
311 channels[i].enabled = uchan->enabled;
312 channels[i].attr.tracefile_size = uchan->tracefile_size;
313 channels[i].attr.tracefile_count = uchan->tracefile_count;
314
315 /*
316 * Map enum lttng_ust_output to enum lttng_event_output.
317 */
318 switch (uchan->attr.output) {
319 case LTTNG_UST_MMAP:
320 channels[i].attr.output = LTTNG_EVENT_MMAP;
321 break;
322 default:
323 /*
324 * LTTNG_UST_MMAP is the only supported UST
325 * output mode.
326 */
327 assert(0);
328 break;
329 }
330
331 chan_exts[i].monitor_timer_interval =
332 uchan->monitor_timer_interval;
333 chan_exts[i].blocking_timeout =
334 uchan->attr.u.s.blocking_timeout;
335
336 ret = get_ust_runtime_stats(session, uchan,
337 &discarded_events, &lost_packets);
338 if (ret < 0) {
339 break;
340 }
341 chan_exts[i].discarded_events = discarded_events;
342 chan_exts[i].lost_packets = lost_packets;
343 i++;
344 }
345 rcu_read_unlock();
346 break;
347 }
348 default:
349 break;
350 }
351
352 end:
353 if (ret < 0) {
354 return -LTTNG_ERR_FATAL;
355 } else {
356 return LTTNG_OK;
357 }
358 }
359
360 static void increment_extended_len(const char *filter_expression,
361 struct lttng_event_exclusion *exclusion, size_t *extended_len)
362 {
363 *extended_len += sizeof(struct lttcomm_event_extended_header);
364
365 if (filter_expression) {
366 *extended_len += strlen(filter_expression) + 1;
367 }
368
369 if (exclusion) {
370 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
371 }
372 }
373
374 static void append_extended_info(const char *filter_expression,
375 struct lttng_event_exclusion *exclusion, void **extended_at)
376 {
377 struct lttcomm_event_extended_header extended_header;
378 size_t filter_len = 0;
379 size_t nb_exclusions = 0;
380
381 if (filter_expression) {
382 filter_len = strlen(filter_expression) + 1;
383 }
384
385 if (exclusion) {
386 nb_exclusions = exclusion->count;
387 }
388
389 /* Set header fields */
390 extended_header.filter_len = filter_len;
391 extended_header.nb_exclusions = nb_exclusions;
392
393 /* Copy header */
394 memcpy(*extended_at, &extended_header, sizeof(extended_header));
395 *extended_at += sizeof(extended_header);
396
397 /* Copy filter string */
398 if (filter_expression) {
399 memcpy(*extended_at, filter_expression, filter_len);
400 *extended_at += filter_len;
401 }
402
403 /* Copy exclusion names */
404 if (exclusion) {
405 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
406
407 memcpy(*extended_at, &exclusion->names, len);
408 *extended_at += len;
409 }
410 }
411
412 /*
413 * Create a list of agent domain events.
414 *
415 * Return number of events in list on success or else a negative value.
416 */
417 static int list_lttng_agent_events(struct agent *agt,
418 struct lttng_event **events, size_t *total_size)
419 {
420 int i = 0, ret = 0;
421 unsigned int nb_event = 0;
422 struct agent_event *event;
423 struct lttng_event *tmp_events;
424 struct lttng_ht_iter iter;
425 size_t extended_len = 0;
426 void *extended_at;
427
428 assert(agt);
429 assert(events);
430
431 DBG3("Listing agent events");
432
433 rcu_read_lock();
434 nb_event = lttng_ht_get_count(agt->events);
435 rcu_read_unlock();
436 if (nb_event == 0) {
437 ret = nb_event;
438 *total_size = 0;
439 goto error;
440 }
441
442 /* Compute required extended infos size */
443 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
444
445 /*
446 * This is only valid because the commands which add events are
447 * processed in the same thread as the listing.
448 */
449 rcu_read_lock();
450 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
451 increment_extended_len(event->filter_expression, NULL,
452 &extended_len);
453 }
454 rcu_read_unlock();
455
456 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
457 tmp_events = zmalloc(*total_size);
458 if (!tmp_events) {
459 PERROR("zmalloc agent events session");
460 ret = -LTTNG_ERR_FATAL;
461 goto error;
462 }
463
464 extended_at = ((uint8_t *) tmp_events) +
465 nb_event * sizeof(struct lttng_event);
466
467 rcu_read_lock();
468 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
469 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
470 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
471 tmp_events[i].enabled = event->enabled;
472 tmp_events[i].loglevel = event->loglevel_value;
473 tmp_events[i].loglevel_type = event->loglevel_type;
474 i++;
475
476 /* Append extended info */
477 append_extended_info(event->filter_expression, NULL,
478 &extended_at);
479 }
480 rcu_read_unlock();
481
482 *events = tmp_events;
483 ret = nb_event;
484
485 error:
486 assert(nb_event == i);
487 return ret;
488 }
489
490 /*
491 * Create a list of ust global domain events.
492 */
493 static int list_lttng_ust_global_events(char *channel_name,
494 struct ltt_ust_domain_global *ust_global,
495 struct lttng_event **events, size_t *total_size)
496 {
497 int i = 0, ret = 0;
498 unsigned int nb_event = 0;
499 struct lttng_ht_iter iter;
500 struct lttng_ht_node_str *node;
501 struct ltt_ust_channel *uchan;
502 struct ltt_ust_event *uevent;
503 struct lttng_event *tmp;
504 size_t extended_len = 0;
505 void *extended_at;
506
507 DBG("Listing UST global events for channel %s", channel_name);
508
509 rcu_read_lock();
510
511 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
512 node = lttng_ht_iter_get_node_str(&iter);
513 if (node == NULL) {
514 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
515 goto end;
516 }
517
518 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
519
520 nb_event = lttng_ht_get_count(uchan->events);
521 if (nb_event == 0) {
522 ret = nb_event;
523 *total_size = 0;
524 goto end;
525 }
526
527 DBG3("Listing UST global %d events", nb_event);
528
529 /* Compute required extended infos size */
530 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
531 if (uevent->internal) {
532 nb_event--;
533 continue;
534 }
535
536 increment_extended_len(uevent->filter_expression,
537 uevent->exclusion, &extended_len);
538 }
539 if (nb_event == 0) {
540 /* All events are internal, skip. */
541 ret = 0;
542 *total_size = 0;
543 goto end;
544 }
545
546 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
547 tmp = zmalloc(*total_size);
548 if (tmp == NULL) {
549 ret = -LTTNG_ERR_FATAL;
550 goto end;
551 }
552
553 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
554
555 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
556 if (uevent->internal) {
557 /* This event should remain hidden from clients */
558 continue;
559 }
560 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
561 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
562 tmp[i].enabled = uevent->enabled;
563
564 switch (uevent->attr.instrumentation) {
565 case LTTNG_UST_TRACEPOINT:
566 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
567 break;
568 case LTTNG_UST_PROBE:
569 tmp[i].type = LTTNG_EVENT_PROBE;
570 break;
571 case LTTNG_UST_FUNCTION:
572 tmp[i].type = LTTNG_EVENT_FUNCTION;
573 break;
574 }
575
576 tmp[i].loglevel = uevent->attr.loglevel;
577 switch (uevent->attr.loglevel_type) {
578 case LTTNG_UST_LOGLEVEL_ALL:
579 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
580 break;
581 case LTTNG_UST_LOGLEVEL_RANGE:
582 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
583 break;
584 case LTTNG_UST_LOGLEVEL_SINGLE:
585 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
586 break;
587 }
588 if (uevent->filter) {
589 tmp[i].filter = 1;
590 }
591 if (uevent->exclusion) {
592 tmp[i].exclusion = 1;
593 }
594 i++;
595
596 /* Append extended info */
597 append_extended_info(uevent->filter_expression,
598 uevent->exclusion, &extended_at);
599 }
600
601 ret = nb_event;
602 *events = tmp;
603 end:
604 rcu_read_unlock();
605 return ret;
606 }
607
608 /*
609 * Fill lttng_event array of all kernel events in the channel.
610 */
611 static int list_lttng_kernel_events(char *channel_name,
612 struct ltt_kernel_session *kernel_session,
613 struct lttng_event **events, size_t *total_size)
614 {
615 int i = 0, ret;
616 unsigned int nb_event;
617 struct ltt_kernel_event *event;
618 struct ltt_kernel_channel *kchan;
619 size_t extended_len = 0;
620 void *extended_at;
621
622 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
623 if (kchan == NULL) {
624 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
625 goto error;
626 }
627
628 nb_event = kchan->event_count;
629
630 DBG("Listing events for channel %s", kchan->channel->name);
631
632 if (nb_event == 0) {
633 *total_size = 0;
634 *events = NULL;
635 goto end;
636 }
637
638 /* Compute required extended infos size */
639 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
640 increment_extended_len(event->filter_expression, NULL,
641 &extended_len);
642 }
643
644 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
645 *events = zmalloc(*total_size);
646 if (*events == NULL) {
647 ret = LTTNG_ERR_FATAL;
648 goto error;
649 }
650
651 extended_at = ((void *) *events) +
652 nb_event * sizeof(struct lttng_event);
653
654 /* Kernel channels */
655 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
656 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
657 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
658 (*events)[i].enabled = event->enabled;
659 (*events)[i].filter =
660 (unsigned char) !!event->filter_expression;
661
662 switch (event->event->instrumentation) {
663 case LTTNG_KERNEL_TRACEPOINT:
664 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
665 break;
666 case LTTNG_KERNEL_KRETPROBE:
667 (*events)[i].type = LTTNG_EVENT_FUNCTION;
668 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
669 sizeof(struct lttng_kernel_kprobe));
670 break;
671 case LTTNG_KERNEL_KPROBE:
672 (*events)[i].type = LTTNG_EVENT_PROBE;
673 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
674 sizeof(struct lttng_kernel_kprobe));
675 break;
676 case LTTNG_KERNEL_FUNCTION:
677 (*events)[i].type = LTTNG_EVENT_FUNCTION;
678 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
679 sizeof(struct lttng_kernel_function));
680 break;
681 case LTTNG_KERNEL_NOOP:
682 (*events)[i].type = LTTNG_EVENT_NOOP;
683 break;
684 case LTTNG_KERNEL_SYSCALL:
685 (*events)[i].type = LTTNG_EVENT_SYSCALL;
686 break;
687 case LTTNG_KERNEL_ALL:
688 assert(0);
689 break;
690 }
691 i++;
692
693 /* Append extended info */
694 append_extended_info(event->filter_expression, NULL,
695 &extended_at);
696 }
697
698 end:
699 return nb_event;
700
701 error:
702 /* Negate the error code to differentiate the size from an error */
703 return -ret;
704 }
705
706 /*
707 * Add URI so the consumer output object. Set the correct path depending on the
708 * domain adding the default trace directory.
709 */
710 static int add_uri_to_consumer(struct consumer_output *consumer,
711 struct lttng_uri *uri, enum lttng_domain_type domain,
712 const char *session_name)
713 {
714 int ret = LTTNG_OK;
715 const char *default_trace_dir;
716
717 assert(uri);
718
719 if (consumer == NULL) {
720 DBG("No consumer detected. Don't add URI. Stopping.");
721 ret = LTTNG_ERR_NO_CONSUMER;
722 goto error;
723 }
724
725 switch (domain) {
726 case LTTNG_DOMAIN_KERNEL:
727 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
728 break;
729 case LTTNG_DOMAIN_UST:
730 default_trace_dir = DEFAULT_UST_TRACE_DIR;
731 break;
732 default:
733 /*
734 * This case is possible is we try to add the URI to the global tracing
735 * session consumer object which in this case there is no subdir.
736 */
737 default_trace_dir = "";
738 }
739
740 switch (uri->dtype) {
741 case LTTNG_DST_IPV4:
742 case LTTNG_DST_IPV6:
743 DBG2("Setting network URI to consumer");
744
745 if (consumer->type == CONSUMER_DST_NET) {
746 if ((uri->stype == LTTNG_STREAM_CONTROL &&
747 consumer->dst.net.control_isset) ||
748 (uri->stype == LTTNG_STREAM_DATA &&
749 consumer->dst.net.data_isset)) {
750 ret = LTTNG_ERR_URL_EXIST;
751 goto error;
752 }
753 } else {
754 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
755 }
756
757 consumer->type = CONSUMER_DST_NET;
758
759 /* Set URI into consumer output object */
760 ret = consumer_set_network_uri(consumer, uri);
761 if (ret < 0) {
762 ret = -ret;
763 goto error;
764 } else if (ret == 1) {
765 /*
766 * URI was the same in the consumer so we do not append the subdir
767 * again so to not duplicate output dir.
768 */
769 ret = LTTNG_OK;
770 goto error;
771 }
772
773 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
774 ret = consumer_set_subdir(consumer, session_name);
775 if (ret < 0) {
776 ret = LTTNG_ERR_FATAL;
777 goto error;
778 }
779 }
780
781 if (uri->stype == LTTNG_STREAM_CONTROL) {
782 /* On a new subdir, reappend the default trace dir. */
783 strncat(consumer->subdir, default_trace_dir,
784 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
785 DBG3("Append domain trace name to subdir %s", consumer->subdir);
786 }
787
788 break;
789 case LTTNG_DST_PATH:
790 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
791 memset(consumer->dst.session_root_path, 0,
792 sizeof(consumer->dst.session_root_path));
793 /* Explicit length checks for strcpy and strcat. */
794 if (strlen(uri->dst.path) + strlen(default_trace_dir)
795 >= sizeof(consumer->dst.session_root_path)) {
796 ret = LTTNG_ERR_FATAL;
797 goto error;
798 }
799 strcpy(consumer->dst.session_root_path, uri->dst.path);
800 /* Append default trace dir */
801 strcat(consumer->dst.session_root_path, default_trace_dir);
802 /* Flag consumer as local. */
803 consumer->type = CONSUMER_DST_LOCAL;
804 break;
805 }
806
807 ret = LTTNG_OK;
808
809 error:
810 return ret;
811 }
812
813 /*
814 * Init tracing by creating trace directory and sending fds kernel consumer.
815 */
816 static int init_kernel_tracing(struct ltt_kernel_session *session)
817 {
818 int ret = 0;
819 struct lttng_ht_iter iter;
820 struct consumer_socket *socket;
821
822 assert(session);
823
824 rcu_read_lock();
825
826 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
827 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
828 socket, node.node) {
829 pthread_mutex_lock(socket->lock);
830 ret = kernel_consumer_send_session(socket, session);
831 pthread_mutex_unlock(socket->lock);
832 if (ret < 0) {
833 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
834 goto error;
835 }
836 }
837 }
838
839 error:
840 rcu_read_unlock();
841 return ret;
842 }
843
844 /*
845 * Create a socket to the relayd using the URI.
846 *
847 * On success, the relayd_sock pointer is set to the created socket.
848 * Else, it's stays untouched and a lttcomm error code is returned.
849 */
850 static int create_connect_relayd(struct lttng_uri *uri,
851 struct lttcomm_relayd_sock **relayd_sock,
852 struct consumer_output *consumer)
853 {
854 int ret;
855 struct lttcomm_relayd_sock *rsock;
856
857 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
858 RELAYD_VERSION_COMM_MINOR);
859 if (!rsock) {
860 ret = LTTNG_ERR_FATAL;
861 goto error;
862 }
863
864 /*
865 * Connect to relayd so we can proceed with a session creation. This call
866 * can possibly block for an arbitrary amount of time to set the health
867 * state to be in poll execution.
868 */
869 health_poll_entry();
870 ret = relayd_connect(rsock);
871 health_poll_exit();
872 if (ret < 0) {
873 ERR("Unable to reach lttng-relayd");
874 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
875 goto free_sock;
876 }
877
878 /* Create socket for control stream. */
879 if (uri->stype == LTTNG_STREAM_CONTROL) {
880 DBG3("Creating relayd stream socket from URI");
881
882 /* Check relayd version */
883 ret = relayd_version_check(rsock);
884 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
885 goto close_sock;
886 } else if (ret < 0) {
887 ERR("Unable to reach lttng-relayd");
888 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
889 goto close_sock;
890 }
891 consumer->relay_major_version = rsock->major;
892 consumer->relay_minor_version = rsock->minor;
893 } else if (uri->stype == LTTNG_STREAM_DATA) {
894 DBG3("Creating relayd data socket from URI");
895 } else {
896 /* Command is not valid */
897 ERR("Relayd invalid stream type: %d", uri->stype);
898 ret = LTTNG_ERR_INVALID;
899 goto close_sock;
900 }
901
902 *relayd_sock = rsock;
903
904 return LTTNG_OK;
905
906 close_sock:
907 /* The returned value is not useful since we are on an error path. */
908 (void) relayd_close(rsock);
909 free_sock:
910 free(rsock);
911 error:
912 return ret;
913 }
914
915 /*
916 * Connect to the relayd using URI and send the socket to the right consumer.
917 *
918 * The consumer socket lock must be held by the caller.
919 */
920 static int send_consumer_relayd_socket(enum lttng_domain_type domain,
921 unsigned int session_id, struct lttng_uri *relayd_uri,
922 struct consumer_output *consumer,
923 struct consumer_socket *consumer_sock,
924 char *session_name, char *hostname, int session_live_timer)
925 {
926 int ret;
927 struct lttcomm_relayd_sock *rsock = NULL;
928
929 /* Connect to relayd and make version check if uri is the control. */
930 ret = create_connect_relayd(relayd_uri, &rsock, consumer);
931 if (ret != LTTNG_OK) {
932 goto relayd_comm_error;
933 }
934 assert(rsock);
935
936 /* Set the network sequence index if not set. */
937 if (consumer->net_seq_index == (uint64_t) -1ULL) {
938 pthread_mutex_lock(&relayd_net_seq_idx_lock);
939 /*
940 * Increment net_seq_idx because we are about to transfer the
941 * new relayd socket to the consumer.
942 * Assign unique key so the consumer can match streams.
943 */
944 consumer->net_seq_index = ++relayd_net_seq_idx;
945 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
946 }
947
948 /* Send relayd socket to consumer. */
949 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
950 relayd_uri->stype, session_id,
951 session_name, hostname, session_live_timer);
952 if (ret < 0) {
953 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
954 goto close_sock;
955 }
956
957 /* Flag that the corresponding socket was sent. */
958 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
959 consumer_sock->control_sock_sent = 1;
960 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
961 consumer_sock->data_sock_sent = 1;
962 }
963
964 ret = LTTNG_OK;
965
966 /*
967 * Close socket which was dup on the consumer side. The session daemon does
968 * NOT keep track of the relayd socket(s) once transfer to the consumer.
969 */
970
971 close_sock:
972 if (ret != LTTNG_OK) {
973 /*
974 * The consumer output for this session should not be used anymore
975 * since the relayd connection failed thus making any tracing or/and
976 * streaming not usable.
977 */
978 consumer->enabled = 0;
979 }
980 (void) relayd_close(rsock);
981 free(rsock);
982
983 relayd_comm_error:
984 return ret;
985 }
986
987 /*
988 * Send both relayd sockets to a specific consumer and domain. This is a
989 * helper function to facilitate sending the information to the consumer for a
990 * session.
991 *
992 * The consumer socket lock must be held by the caller.
993 */
994 static int send_consumer_relayd_sockets(enum lttng_domain_type domain,
995 unsigned int session_id, struct consumer_output *consumer,
996 struct consumer_socket *sock, char *session_name,
997 char *hostname, int session_live_timer)
998 {
999 int ret = LTTNG_OK;
1000
1001 assert(consumer);
1002 assert(sock);
1003
1004 /* Sending control relayd socket. */
1005 if (!sock->control_sock_sent) {
1006 ret = send_consumer_relayd_socket(domain, session_id,
1007 &consumer->dst.net.control, consumer, sock,
1008 session_name, hostname, session_live_timer);
1009 if (ret != LTTNG_OK) {
1010 goto error;
1011 }
1012 }
1013
1014 /* Sending data relayd socket. */
1015 if (!sock->data_sock_sent) {
1016 ret = send_consumer_relayd_socket(domain, session_id,
1017 &consumer->dst.net.data, consumer, sock,
1018 session_name, hostname, session_live_timer);
1019 if (ret != LTTNG_OK) {
1020 goto error;
1021 }
1022 }
1023
1024 error:
1025 return ret;
1026 }
1027
1028 /*
1029 * Setup relayd connections for a tracing session. First creates the socket to
1030 * the relayd and send them to the right domain consumer. Consumer type MUST be
1031 * network.
1032 */
1033 int cmd_setup_relayd(struct ltt_session *session)
1034 {
1035 int ret = LTTNG_OK;
1036 struct ltt_ust_session *usess;
1037 struct ltt_kernel_session *ksess;
1038 struct consumer_socket *socket;
1039 struct lttng_ht_iter iter;
1040
1041 assert(session);
1042
1043 usess = session->ust_session;
1044 ksess = session->kernel_session;
1045
1046 DBG("Setting relayd for session %s", session->name);
1047
1048 rcu_read_lock();
1049
1050 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1051 && usess->consumer->enabled) {
1052 /* For each consumer socket, send relayd sockets */
1053 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1054 socket, node.node) {
1055 pthread_mutex_lock(socket->lock);
1056 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1057 usess->consumer, socket,
1058 session->name, session->hostname,
1059 session->live_timer);
1060 pthread_mutex_unlock(socket->lock);
1061 if (ret != LTTNG_OK) {
1062 goto error;
1063 }
1064 /* Session is now ready for network streaming. */
1065 session->net_handle = 1;
1066 }
1067 session->consumer->relay_major_version =
1068 usess->consumer->relay_major_version;
1069 session->consumer->relay_minor_version =
1070 usess->consumer->relay_minor_version;
1071 }
1072
1073 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1074 && ksess->consumer->enabled) {
1075 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1076 socket, node.node) {
1077 pthread_mutex_lock(socket->lock);
1078 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1079 ksess->consumer, socket,
1080 session->name, session->hostname,
1081 session->live_timer);
1082 pthread_mutex_unlock(socket->lock);
1083 if (ret != LTTNG_OK) {
1084 goto error;
1085 }
1086 /* Session is now ready for network streaming. */
1087 session->net_handle = 1;
1088 }
1089 session->consumer->relay_major_version =
1090 ksess->consumer->relay_major_version;
1091 session->consumer->relay_minor_version =
1092 ksess->consumer->relay_minor_version;
1093 }
1094
1095 error:
1096 rcu_read_unlock();
1097 return ret;
1098 }
1099
1100 /*
1101 * Start a kernel session by opening all necessary streams.
1102 */
1103 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1104 {
1105 int ret;
1106 struct ltt_kernel_channel *kchan;
1107
1108 /* Open kernel metadata */
1109 if (ksess->metadata == NULL && ksess->output_traces) {
1110 ret = kernel_open_metadata(ksess);
1111 if (ret < 0) {
1112 ret = LTTNG_ERR_KERN_META_FAIL;
1113 goto error;
1114 }
1115 }
1116
1117 /* Open kernel metadata stream */
1118 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1119 ret = kernel_open_metadata_stream(ksess);
1120 if (ret < 0) {
1121 ERR("Kernel create metadata stream failed");
1122 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1123 goto error;
1124 }
1125 }
1126
1127 /* For each channel */
1128 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1129 if (kchan->stream_count == 0) {
1130 ret = kernel_open_channel_stream(kchan);
1131 if (ret < 0) {
1132 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1133 goto error;
1134 }
1135 /* Update the stream global counter */
1136 ksess->stream_count_global += ret;
1137 }
1138 }
1139
1140 /* Setup kernel consumer socket and send fds to it */
1141 ret = init_kernel_tracing(ksess);
1142 if (ret != 0) {
1143 ret = LTTNG_ERR_KERN_START_FAIL;
1144 goto error;
1145 }
1146
1147 /* This start the kernel tracing */
1148 ret = kernel_start_session(ksess);
1149 if (ret < 0) {
1150 ret = LTTNG_ERR_KERN_START_FAIL;
1151 goto error;
1152 }
1153
1154 /* Quiescent wait after starting trace */
1155 kernel_wait_quiescent(kernel_tracer_fd);
1156
1157 ksess->active = 1;
1158
1159 ret = LTTNG_OK;
1160
1161 error:
1162 return ret;
1163 }
1164
1165 /*
1166 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1167 */
1168 int cmd_disable_channel(struct ltt_session *session,
1169 enum lttng_domain_type domain, char *channel_name)
1170 {
1171 int ret;
1172 struct ltt_ust_session *usess;
1173
1174 usess = session->ust_session;
1175
1176 rcu_read_lock();
1177
1178 switch (domain) {
1179 case LTTNG_DOMAIN_KERNEL:
1180 {
1181 ret = channel_kernel_disable(session->kernel_session,
1182 channel_name);
1183 if (ret != LTTNG_OK) {
1184 goto error;
1185 }
1186
1187 kernel_wait_quiescent(kernel_tracer_fd);
1188 break;
1189 }
1190 case LTTNG_DOMAIN_UST:
1191 {
1192 struct ltt_ust_channel *uchan;
1193 struct lttng_ht *chan_ht;
1194
1195 chan_ht = usess->domain_global.channels;
1196
1197 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1198 if (uchan == NULL) {
1199 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1200 goto error;
1201 }
1202
1203 ret = channel_ust_disable(usess, uchan);
1204 if (ret != LTTNG_OK) {
1205 goto error;
1206 }
1207 break;
1208 }
1209 default:
1210 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1211 goto error;
1212 }
1213
1214 ret = LTTNG_OK;
1215
1216 error:
1217 rcu_read_unlock();
1218 return ret;
1219 }
1220
1221 /*
1222 * Command LTTNG_TRACK_PID processed by the client thread.
1223 *
1224 * Called with session lock held.
1225 */
1226 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1227 int pid)
1228 {
1229 int ret;
1230
1231 rcu_read_lock();
1232
1233 switch (domain) {
1234 case LTTNG_DOMAIN_KERNEL:
1235 {
1236 struct ltt_kernel_session *ksess;
1237
1238 ksess = session->kernel_session;
1239
1240 ret = kernel_track_pid(ksess, pid);
1241 if (ret != LTTNG_OK) {
1242 goto error;
1243 }
1244
1245 kernel_wait_quiescent(kernel_tracer_fd);
1246 break;
1247 }
1248 case LTTNG_DOMAIN_UST:
1249 {
1250 struct ltt_ust_session *usess;
1251
1252 usess = session->ust_session;
1253
1254 ret = trace_ust_track_pid(usess, pid);
1255 if (ret != LTTNG_OK) {
1256 goto error;
1257 }
1258 break;
1259 }
1260 default:
1261 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1262 goto error;
1263 }
1264
1265 ret = LTTNG_OK;
1266
1267 error:
1268 rcu_read_unlock();
1269 return ret;
1270 }
1271
1272 /*
1273 * Command LTTNG_UNTRACK_PID processed by the client thread.
1274 *
1275 * Called with session lock held.
1276 */
1277 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1278 int pid)
1279 {
1280 int ret;
1281
1282 rcu_read_lock();
1283
1284 switch (domain) {
1285 case LTTNG_DOMAIN_KERNEL:
1286 {
1287 struct ltt_kernel_session *ksess;
1288
1289 ksess = session->kernel_session;
1290
1291 ret = kernel_untrack_pid(ksess, pid);
1292 if (ret != LTTNG_OK) {
1293 goto error;
1294 }
1295
1296 kernel_wait_quiescent(kernel_tracer_fd);
1297 break;
1298 }
1299 case LTTNG_DOMAIN_UST:
1300 {
1301 struct ltt_ust_session *usess;
1302
1303 usess = session->ust_session;
1304
1305 ret = trace_ust_untrack_pid(usess, pid);
1306 if (ret != LTTNG_OK) {
1307 goto error;
1308 }
1309 break;
1310 }
1311 default:
1312 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1313 goto error;
1314 }
1315
1316 ret = LTTNG_OK;
1317
1318 error:
1319 rcu_read_unlock();
1320 return ret;
1321 }
1322
1323 /*
1324 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1325 *
1326 * The wpipe arguments is used as a notifier for the kernel thread.
1327 */
1328 int cmd_enable_channel(struct ltt_session *session,
1329 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1330 {
1331 int ret;
1332 struct ltt_ust_session *usess = session->ust_session;
1333 struct lttng_ht *chan_ht;
1334 size_t len;
1335
1336 assert(session);
1337 assert(attr);
1338 assert(domain);
1339
1340 len = lttng_strnlen(attr->name, sizeof(attr->name));
1341
1342 /* Validate channel name */
1343 if (attr->name[0] == '.' ||
1344 memchr(attr->name, '/', len) != NULL) {
1345 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1346 goto end;
1347 }
1348
1349 DBG("Enabling channel %s for session %s", attr->name, session->name);
1350
1351 rcu_read_lock();
1352
1353 /*
1354 * Don't try to enable a channel if the session has been started at
1355 * some point in time before. The tracer does not allow it.
1356 */
1357 if (session->has_been_started) {
1358 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1359 goto error;
1360 }
1361
1362 /*
1363 * If the session is a live session, remove the switch timer, the
1364 * live timer does the same thing but sends also synchronisation
1365 * beacons for inactive streams.
1366 */
1367 if (session->live_timer > 0) {
1368 attr->attr.live_timer_interval = session->live_timer;
1369 attr->attr.switch_timer_interval = 0;
1370 }
1371
1372 /* Check for feature support */
1373 switch (domain->type) {
1374 case LTTNG_DOMAIN_KERNEL:
1375 {
1376 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1377 /* Sampling position of buffer is not supported */
1378 WARN("Kernel tracer does not support buffer monitoring. "
1379 "Setting the monitor interval timer to 0 "
1380 "(disabled) for channel '%s' of session '%s'",
1381 attr-> name, session->name);
1382 lttng_channel_set_monitor_timer_interval(attr, 0);
1383 }
1384 break;
1385 }
1386 case LTTNG_DOMAIN_UST:
1387 case LTTNG_DOMAIN_JUL:
1388 case LTTNG_DOMAIN_LOG4J:
1389 case LTTNG_DOMAIN_PYTHON:
1390 break;
1391 default:
1392 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1393 goto error;
1394 }
1395
1396 switch (domain->type) {
1397 case LTTNG_DOMAIN_KERNEL:
1398 {
1399 struct ltt_kernel_channel *kchan;
1400
1401 kchan = trace_kernel_get_channel_by_name(attr->name,
1402 session->kernel_session);
1403 if (kchan == NULL) {
1404 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1405 if (attr->name[0] != '\0') {
1406 session->kernel_session->has_non_default_channel = 1;
1407 }
1408 } else {
1409 ret = channel_kernel_enable(session->kernel_session, kchan);
1410 }
1411
1412 if (ret != LTTNG_OK) {
1413 goto error;
1414 }
1415
1416 kernel_wait_quiescent(kernel_tracer_fd);
1417 break;
1418 }
1419 case LTTNG_DOMAIN_UST:
1420 case LTTNG_DOMAIN_JUL:
1421 case LTTNG_DOMAIN_LOG4J:
1422 case LTTNG_DOMAIN_PYTHON:
1423 {
1424 struct ltt_ust_channel *uchan;
1425
1426 /*
1427 * FIXME
1428 *
1429 * Current agent implementation limitations force us to allow
1430 * only one channel at once in "agent" subdomains. Each
1431 * subdomain has a default channel name which must be strictly
1432 * adhered to.
1433 */
1434 if (domain->type == LTTNG_DOMAIN_JUL) {
1435 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1436 LTTNG_SYMBOL_NAME_LEN)) {
1437 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1438 goto error;
1439 }
1440 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1441 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1442 LTTNG_SYMBOL_NAME_LEN)) {
1443 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1444 goto error;
1445 }
1446 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1447 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1448 LTTNG_SYMBOL_NAME_LEN)) {
1449 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1450 goto error;
1451 }
1452 }
1453
1454 chan_ht = usess->domain_global.channels;
1455
1456 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1457 if (uchan == NULL) {
1458 ret = channel_ust_create(usess, attr, domain->buf_type);
1459 if (attr->name[0] != '\0') {
1460 usess->has_non_default_channel = 1;
1461 }
1462 } else {
1463 ret = channel_ust_enable(usess, uchan);
1464 }
1465 break;
1466 }
1467 default:
1468 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1469 goto error;
1470 }
1471
1472 error:
1473 rcu_read_unlock();
1474 end:
1475 return ret;
1476 }
1477
1478 /*
1479 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1480 */
1481 int cmd_disable_event(struct ltt_session *session,
1482 enum lttng_domain_type domain, char *channel_name,
1483 struct lttng_event *event)
1484 {
1485 int ret;
1486 char *event_name;
1487
1488 DBG("Disable event command for event \'%s\'", event->name);
1489
1490 event_name = event->name;
1491
1492 /* Error out on unhandled search criteria */
1493 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1494 || event->pid || event->filter || event->exclusion) {
1495 ret = LTTNG_ERR_UNK;
1496 goto error;
1497 }
1498
1499 rcu_read_lock();
1500
1501 switch (domain) {
1502 case LTTNG_DOMAIN_KERNEL:
1503 {
1504 struct ltt_kernel_channel *kchan;
1505 struct ltt_kernel_session *ksess;
1506
1507 ksess = session->kernel_session;
1508
1509 /*
1510 * If a non-default channel has been created in the
1511 * session, explicitely require that -c chan_name needs
1512 * to be provided.
1513 */
1514 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1515 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1516 goto error_unlock;
1517 }
1518
1519 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1520 if (kchan == NULL) {
1521 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1522 goto error_unlock;
1523 }
1524
1525 switch (event->type) {
1526 case LTTNG_EVENT_ALL:
1527 case LTTNG_EVENT_TRACEPOINT:
1528 case LTTNG_EVENT_SYSCALL:
1529 case LTTNG_EVENT_PROBE:
1530 case LTTNG_EVENT_FUNCTION:
1531 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1532 if (event_name[0] == '\0') {
1533 ret = event_kernel_disable_event(kchan,
1534 NULL, event->type);
1535 } else {
1536 ret = event_kernel_disable_event(kchan,
1537 event_name, event->type);
1538 }
1539 if (ret != LTTNG_OK) {
1540 goto error_unlock;
1541 }
1542 break;
1543 default:
1544 ret = LTTNG_ERR_UNK;
1545 goto error_unlock;
1546 }
1547
1548 kernel_wait_quiescent(kernel_tracer_fd);
1549 break;
1550 }
1551 case LTTNG_DOMAIN_UST:
1552 {
1553 struct ltt_ust_channel *uchan;
1554 struct ltt_ust_session *usess;
1555
1556 usess = session->ust_session;
1557
1558 if (validate_ust_event_name(event_name)) {
1559 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1560 goto error_unlock;
1561 }
1562
1563 /*
1564 * If a non-default channel has been created in the
1565 * session, explicitly require that -c chan_name needs
1566 * to be provided.
1567 */
1568 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1569 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1570 goto error_unlock;
1571 }
1572
1573 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1574 channel_name);
1575 if (uchan == NULL) {
1576 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1577 goto error_unlock;
1578 }
1579
1580 switch (event->type) {
1581 case LTTNG_EVENT_ALL:
1582 /*
1583 * An empty event name means that everything
1584 * should be disabled.
1585 */
1586 if (event->name[0] == '\0') {
1587 ret = event_ust_disable_all_tracepoints(usess, uchan);
1588 } else {
1589 ret = event_ust_disable_tracepoint(usess, uchan,
1590 event_name);
1591 }
1592 if (ret != LTTNG_OK) {
1593 goto error_unlock;
1594 }
1595 break;
1596 default:
1597 ret = LTTNG_ERR_UNK;
1598 goto error_unlock;
1599 }
1600
1601 DBG3("Disable UST event %s in channel %s completed", event_name,
1602 channel_name);
1603 break;
1604 }
1605 case LTTNG_DOMAIN_LOG4J:
1606 case LTTNG_DOMAIN_JUL:
1607 case LTTNG_DOMAIN_PYTHON:
1608 {
1609 struct agent *agt;
1610 struct ltt_ust_session *usess = session->ust_session;
1611
1612 assert(usess);
1613
1614 switch (event->type) {
1615 case LTTNG_EVENT_ALL:
1616 break;
1617 default:
1618 ret = LTTNG_ERR_UNK;
1619 goto error_unlock;
1620 }
1621
1622 agt = trace_ust_find_agent(usess, domain);
1623 if (!agt) {
1624 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1625 goto error_unlock;
1626 }
1627 /*
1628 * An empty event name means that everything
1629 * should be disabled.
1630 */
1631 if (event->name[0] == '\0') {
1632 ret = event_agent_disable_all(usess, agt);
1633 } else {
1634 ret = event_agent_disable(usess, agt, event_name);
1635 }
1636 if (ret != LTTNG_OK) {
1637 goto error_unlock;
1638 }
1639
1640 break;
1641 }
1642 default:
1643 ret = LTTNG_ERR_UND;
1644 goto error_unlock;
1645 }
1646
1647 ret = LTTNG_OK;
1648
1649 error_unlock:
1650 rcu_read_unlock();
1651 error:
1652 return ret;
1653 }
1654
1655 /*
1656 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1657 */
1658 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1659 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1660 {
1661 int ret, chan_kern_created = 0, chan_ust_created = 0;
1662 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1663
1664 /*
1665 * Don't try to add a context if the session has been started at
1666 * some point in time before. The tracer does not allow it and would
1667 * result in a corrupted trace.
1668 */
1669 if (session->has_been_started) {
1670 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1671 goto end;
1672 }
1673
1674 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1675 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1676 app_ctx_name = ctx->u.app_ctx.ctx_name;
1677 }
1678
1679 switch (domain) {
1680 case LTTNG_DOMAIN_KERNEL:
1681 assert(session->kernel_session);
1682
1683 if (session->kernel_session->channel_count == 0) {
1684 /* Create default channel */
1685 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1686 if (ret != LTTNG_OK) {
1687 goto error;
1688 }
1689 chan_kern_created = 1;
1690 }
1691 /* Add kernel context to kernel tracer */
1692 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1693 if (ret != LTTNG_OK) {
1694 goto error;
1695 }
1696 break;
1697 case LTTNG_DOMAIN_JUL:
1698 case LTTNG_DOMAIN_LOG4J:
1699 {
1700 /*
1701 * Validate channel name.
1702 * If no channel name is given and the domain is JUL or LOG4J,
1703 * set it to the appropriate domain-specific channel name. If
1704 * a name is provided but does not match the expexted channel
1705 * name, return an error.
1706 */
1707 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1708 strcmp(channel_name,
1709 DEFAULT_JUL_CHANNEL_NAME)) {
1710 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1711 goto error;
1712 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1713 strcmp(channel_name,
1714 DEFAULT_LOG4J_CHANNEL_NAME)) {
1715 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1716 goto error;
1717 }
1718 /* break is _not_ missing here. */
1719 }
1720 case LTTNG_DOMAIN_UST:
1721 {
1722 struct ltt_ust_session *usess = session->ust_session;
1723 unsigned int chan_count;
1724
1725 assert(usess);
1726
1727 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1728 if (chan_count == 0) {
1729 struct lttng_channel *attr;
1730 /* Create default channel */
1731 attr = channel_new_default_attr(domain, usess->buffer_type);
1732 if (attr == NULL) {
1733 ret = LTTNG_ERR_FATAL;
1734 goto error;
1735 }
1736
1737 ret = channel_ust_create(usess, attr, usess->buffer_type);
1738 if (ret != LTTNG_OK) {
1739 free(attr);
1740 goto error;
1741 }
1742 channel_attr_destroy(attr);
1743 chan_ust_created = 1;
1744 }
1745
1746 ret = context_ust_add(usess, domain, ctx, channel_name);
1747 free(app_ctx_provider_name);
1748 free(app_ctx_name);
1749 app_ctx_name = NULL;
1750 app_ctx_provider_name = NULL;
1751 if (ret != LTTNG_OK) {
1752 goto error;
1753 }
1754 break;
1755 }
1756 default:
1757 ret = LTTNG_ERR_UND;
1758 goto error;
1759 }
1760
1761 ret = LTTNG_OK;
1762 goto end;
1763
1764 error:
1765 if (chan_kern_created) {
1766 struct ltt_kernel_channel *kchan =
1767 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1768 session->kernel_session);
1769 /* Created previously, this should NOT fail. */
1770 assert(kchan);
1771 kernel_destroy_channel(kchan);
1772 }
1773
1774 if (chan_ust_created) {
1775 struct ltt_ust_channel *uchan =
1776 trace_ust_find_channel_by_name(
1777 session->ust_session->domain_global.channels,
1778 DEFAULT_CHANNEL_NAME);
1779 /* Created previously, this should NOT fail. */
1780 assert(uchan);
1781 /* Remove from the channel list of the session. */
1782 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1783 uchan);
1784 trace_ust_destroy_channel(uchan);
1785 }
1786 end:
1787 free(app_ctx_provider_name);
1788 free(app_ctx_name);
1789 return ret;
1790 }
1791
1792 static inline bool name_starts_with(const char *name, const char *prefix)
1793 {
1794 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1795
1796 return !strncmp(name, prefix, max_cmp_len);
1797 }
1798
1799 /* Perform userspace-specific event name validation */
1800 static int validate_ust_event_name(const char *name)
1801 {
1802 int ret = 0;
1803
1804 if (!name) {
1805 ret = -1;
1806 goto end;
1807 }
1808
1809 /*
1810 * Check name against all internal UST event component namespaces used
1811 * by the agents.
1812 */
1813 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1814 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1815 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1816 ret = -1;
1817 }
1818
1819 end:
1820 return ret;
1821 }
1822
1823 /*
1824 * Internal version of cmd_enable_event() with a supplemental
1825 * "internal_event" flag which is used to enable internal events which should
1826 * be hidden from clients. Such events are used in the agent implementation to
1827 * enable the events through which all "agent" events are funeled.
1828 */
1829 static int _cmd_enable_event(struct ltt_session *session,
1830 struct lttng_domain *domain,
1831 char *channel_name, struct lttng_event *event,
1832 char *filter_expression,
1833 struct lttng_filter_bytecode *filter,
1834 struct lttng_event_exclusion *exclusion,
1835 int wpipe, bool internal_event)
1836 {
1837 int ret = 0, channel_created = 0;
1838 struct lttng_channel *attr = NULL;
1839
1840 assert(session);
1841 assert(event);
1842 assert(channel_name);
1843
1844 /* If we have a filter, we must have its filter expression */
1845 assert(!(!!filter_expression ^ !!filter));
1846
1847 /* Normalize event name as a globbing pattern */
1848 strutils_normalize_star_glob_pattern(event->name);
1849
1850 /* Normalize exclusion names as globbing patterns */
1851 if (exclusion) {
1852 size_t i;
1853
1854 for (i = 0; i < exclusion->count; i++) {
1855 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
1856
1857 strutils_normalize_star_glob_pattern(name);
1858 }
1859 }
1860
1861 DBG("Enable event command for event \'%s\'", event->name);
1862
1863 rcu_read_lock();
1864
1865 switch (domain->type) {
1866 case LTTNG_DOMAIN_KERNEL:
1867 {
1868 struct ltt_kernel_channel *kchan;
1869
1870 /*
1871 * If a non-default channel has been created in the
1872 * session, explicitely require that -c chan_name needs
1873 * to be provided.
1874 */
1875 if (session->kernel_session->has_non_default_channel
1876 && channel_name[0] == '\0') {
1877 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1878 goto error;
1879 }
1880
1881 kchan = trace_kernel_get_channel_by_name(channel_name,
1882 session->kernel_session);
1883 if (kchan == NULL) {
1884 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
1885 LTTNG_BUFFER_GLOBAL);
1886 if (attr == NULL) {
1887 ret = LTTNG_ERR_FATAL;
1888 goto error;
1889 }
1890 if (lttng_strncpy(attr->name, channel_name,
1891 sizeof(attr->name))) {
1892 ret = LTTNG_ERR_INVALID;
1893 goto error;
1894 }
1895
1896 ret = cmd_enable_channel(session, domain, attr, wpipe);
1897 if (ret != LTTNG_OK) {
1898 goto error;
1899 }
1900 channel_created = 1;
1901 }
1902
1903 /* Get the newly created kernel channel pointer */
1904 kchan = trace_kernel_get_channel_by_name(channel_name,
1905 session->kernel_session);
1906 if (kchan == NULL) {
1907 /* This sould not happen... */
1908 ret = LTTNG_ERR_FATAL;
1909 goto error;
1910 }
1911
1912 switch (event->type) {
1913 case LTTNG_EVENT_ALL:
1914 {
1915 char *filter_expression_a = NULL;
1916 struct lttng_filter_bytecode *filter_a = NULL;
1917
1918 /*
1919 * We need to duplicate filter_expression and filter,
1920 * because ownership is passed to first enable
1921 * event.
1922 */
1923 if (filter_expression) {
1924 filter_expression_a = strdup(filter_expression);
1925 if (!filter_expression_a) {
1926 ret = LTTNG_ERR_FATAL;
1927 goto error;
1928 }
1929 }
1930 if (filter) {
1931 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
1932 if (!filter_a) {
1933 free(filter_expression_a);
1934 ret = LTTNG_ERR_FATAL;
1935 goto error;
1936 }
1937 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
1938 }
1939 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
1940 ret = event_kernel_enable_event(kchan, event,
1941 filter_expression, filter);
1942 /* We have passed ownership */
1943 filter_expression = NULL;
1944 filter = NULL;
1945 if (ret != LTTNG_OK) {
1946 if (channel_created) {
1947 /* Let's not leak a useless channel. */
1948 kernel_destroy_channel(kchan);
1949 }
1950 free(filter_expression_a);
1951 free(filter_a);
1952 goto error;
1953 }
1954 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
1955 ret = event_kernel_enable_event(kchan, event,
1956 filter_expression_a, filter_a);
1957 /* We have passed ownership */
1958 filter_expression_a = NULL;
1959 filter_a = NULL;
1960 if (ret != LTTNG_OK) {
1961 goto error;
1962 }
1963 break;
1964 }
1965 case LTTNG_EVENT_PROBE:
1966 case LTTNG_EVENT_FUNCTION:
1967 case LTTNG_EVENT_FUNCTION_ENTRY:
1968 case LTTNG_EVENT_TRACEPOINT:
1969 ret = event_kernel_enable_event(kchan, event,
1970 filter_expression, filter);
1971 /* We have passed ownership */
1972 filter_expression = NULL;
1973 filter = NULL;
1974 if (ret != LTTNG_OK) {
1975 if (channel_created) {
1976 /* Let's not leak a useless channel. */
1977 kernel_destroy_channel(kchan);
1978 }
1979 goto error;
1980 }
1981 break;
1982 case LTTNG_EVENT_SYSCALL:
1983 ret = event_kernel_enable_event(kchan, event,
1984 filter_expression, filter);
1985 /* We have passed ownership */
1986 filter_expression = NULL;
1987 filter = NULL;
1988 if (ret != LTTNG_OK) {
1989 goto error;
1990 }
1991 break;
1992 default:
1993 ret = LTTNG_ERR_UNK;
1994 goto error;
1995 }
1996
1997 kernel_wait_quiescent(kernel_tracer_fd);
1998 break;
1999 }
2000 case LTTNG_DOMAIN_UST:
2001 {
2002 struct ltt_ust_channel *uchan;
2003 struct ltt_ust_session *usess = session->ust_session;
2004
2005 assert(usess);
2006
2007 /*
2008 * If a non-default channel has been created in the
2009 * session, explicitely require that -c chan_name needs
2010 * to be provided.
2011 */
2012 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2013 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2014 goto error;
2015 }
2016
2017 /* Get channel from global UST domain */
2018 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2019 channel_name);
2020 if (uchan == NULL) {
2021 /* Create default channel */
2022 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2023 usess->buffer_type);
2024 if (attr == NULL) {
2025 ret = LTTNG_ERR_FATAL;
2026 goto error;
2027 }
2028 if (lttng_strncpy(attr->name, channel_name,
2029 sizeof(attr->name))) {
2030 ret = LTTNG_ERR_INVALID;
2031 goto error;
2032 }
2033
2034 ret = cmd_enable_channel(session, domain, attr, wpipe);
2035 if (ret != LTTNG_OK) {
2036 goto error;
2037 }
2038
2039 /* Get the newly created channel reference back */
2040 uchan = trace_ust_find_channel_by_name(
2041 usess->domain_global.channels, channel_name);
2042 assert(uchan);
2043 }
2044
2045 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2046 /*
2047 * Don't allow users to add UST events to channels which
2048 * are assigned to a userspace subdomain (JUL, Log4J,
2049 * Python, etc.).
2050 */
2051 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2052 goto error;
2053 }
2054
2055 if (!internal_event) {
2056 /*
2057 * Ensure the event name is not reserved for internal
2058 * use.
2059 */
2060 ret = validate_ust_event_name(event->name);
2061 if (ret) {
2062 WARN("Userspace event name %s failed validation.",
2063 event->name ?
2064 event->name : "NULL");
2065 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2066 goto error;
2067 }
2068 }
2069
2070 /* At this point, the session and channel exist on the tracer */
2071 ret = event_ust_enable_tracepoint(usess, uchan, event,
2072 filter_expression, filter, exclusion,
2073 internal_event);
2074 /* We have passed ownership */
2075 filter_expression = NULL;
2076 filter = NULL;
2077 exclusion = NULL;
2078 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2079 goto already_enabled;
2080 } else if (ret != LTTNG_OK) {
2081 goto error;
2082 }
2083 break;
2084 }
2085 case LTTNG_DOMAIN_LOG4J:
2086 case LTTNG_DOMAIN_JUL:
2087 case LTTNG_DOMAIN_PYTHON:
2088 {
2089 const char *default_event_name, *default_chan_name;
2090 struct agent *agt;
2091 struct lttng_event uevent;
2092 struct lttng_domain tmp_dom;
2093 struct ltt_ust_session *usess = session->ust_session;
2094
2095 assert(usess);
2096
2097 agt = trace_ust_find_agent(usess, domain->type);
2098 if (!agt) {
2099 agt = agent_create(domain->type);
2100 if (!agt) {
2101 ret = LTTNG_ERR_NOMEM;
2102 goto error;
2103 }
2104 agent_add(agt, usess->agents);
2105 }
2106
2107 /* Create the default tracepoint. */
2108 memset(&uevent, 0, sizeof(uevent));
2109 uevent.type = LTTNG_EVENT_TRACEPOINT;
2110 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2111 default_event_name = event_get_default_agent_ust_name(
2112 domain->type);
2113 if (!default_event_name) {
2114 ret = LTTNG_ERR_FATAL;
2115 goto error;
2116 }
2117 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2118 uevent.name[sizeof(uevent.name) - 1] = '\0';
2119
2120 /*
2121 * The domain type is changed because we are about to enable the
2122 * default channel and event for the JUL domain that are hardcoded.
2123 * This happens in the UST domain.
2124 */
2125 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2126 tmp_dom.type = LTTNG_DOMAIN_UST;
2127
2128 switch (domain->type) {
2129 case LTTNG_DOMAIN_LOG4J:
2130 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2131 break;
2132 case LTTNG_DOMAIN_JUL:
2133 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2134 break;
2135 case LTTNG_DOMAIN_PYTHON:
2136 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2137 break;
2138 default:
2139 /* The switch/case we are in makes this impossible */
2140 assert(0);
2141 }
2142
2143 {
2144 char *filter_expression_copy = NULL;
2145 struct lttng_filter_bytecode *filter_copy = NULL;
2146
2147 if (filter) {
2148 const size_t filter_size = sizeof(
2149 struct lttng_filter_bytecode)
2150 + filter->len;
2151
2152 filter_copy = zmalloc(filter_size);
2153 if (!filter_copy) {
2154 ret = LTTNG_ERR_NOMEM;
2155 goto error;
2156 }
2157 memcpy(filter_copy, filter, filter_size);
2158
2159 filter_expression_copy =
2160 strdup(filter_expression);
2161 if (!filter_expression) {
2162 ret = LTTNG_ERR_NOMEM;
2163 }
2164
2165 if (!filter_expression_copy || !filter_copy) {
2166 free(filter_expression_copy);
2167 free(filter_copy);
2168 goto error;
2169 }
2170 }
2171
2172 ret = cmd_enable_event_internal(session, &tmp_dom,
2173 (char *) default_chan_name,
2174 &uevent, filter_expression_copy,
2175 filter_copy, NULL, wpipe);
2176 }
2177
2178 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2179 goto already_enabled;
2180 } else if (ret != LTTNG_OK) {
2181 goto error;
2182 }
2183
2184 /* The wild card * means that everything should be enabled. */
2185 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2186 ret = event_agent_enable_all(usess, agt, event, filter,
2187 filter_expression);
2188 } else {
2189 ret = event_agent_enable(usess, agt, event, filter,
2190 filter_expression);
2191 }
2192 filter = NULL;
2193 filter_expression = NULL;
2194 if (ret != LTTNG_OK) {
2195 goto error;
2196 }
2197
2198 break;
2199 }
2200 default:
2201 ret = LTTNG_ERR_UND;
2202 goto error;
2203 }
2204
2205 ret = LTTNG_OK;
2206
2207 already_enabled:
2208 error:
2209 free(filter_expression);
2210 free(filter);
2211 free(exclusion);
2212 channel_attr_destroy(attr);
2213 rcu_read_unlock();
2214 return ret;
2215 }
2216
2217 /*
2218 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2219 * We own filter, exclusion, and filter_expression.
2220 */
2221 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2222 char *channel_name, struct lttng_event *event,
2223 char *filter_expression,
2224 struct lttng_filter_bytecode *filter,
2225 struct lttng_event_exclusion *exclusion,
2226 int wpipe)
2227 {
2228 return _cmd_enable_event(session, domain, channel_name, event,
2229 filter_expression, filter, exclusion, wpipe, false);
2230 }
2231
2232 /*
2233 * Enable an event which is internal to LTTng. An internal should
2234 * never be made visible to clients and are immune to checks such as
2235 * reserved names.
2236 */
2237 static int cmd_enable_event_internal(struct ltt_session *session,
2238 struct lttng_domain *domain,
2239 char *channel_name, struct lttng_event *event,
2240 char *filter_expression,
2241 struct lttng_filter_bytecode *filter,
2242 struct lttng_event_exclusion *exclusion,
2243 int wpipe)
2244 {
2245 return _cmd_enable_event(session, domain, channel_name, event,
2246 filter_expression, filter, exclusion, wpipe, true);
2247 }
2248
2249 /*
2250 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2251 */
2252 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2253 struct lttng_event **events)
2254 {
2255 int ret;
2256 ssize_t nb_events = 0;
2257
2258 switch (domain) {
2259 case LTTNG_DOMAIN_KERNEL:
2260 nb_events = kernel_list_events(kernel_tracer_fd, events);
2261 if (nb_events < 0) {
2262 ret = LTTNG_ERR_KERN_LIST_FAIL;
2263 goto error;
2264 }
2265 break;
2266 case LTTNG_DOMAIN_UST:
2267 nb_events = ust_app_list_events(events);
2268 if (nb_events < 0) {
2269 ret = LTTNG_ERR_UST_LIST_FAIL;
2270 goto error;
2271 }
2272 break;
2273 case LTTNG_DOMAIN_LOG4J:
2274 case LTTNG_DOMAIN_JUL:
2275 case LTTNG_DOMAIN_PYTHON:
2276 nb_events = agent_list_events(events, domain);
2277 if (nb_events < 0) {
2278 ret = LTTNG_ERR_UST_LIST_FAIL;
2279 goto error;
2280 }
2281 break;
2282 default:
2283 ret = LTTNG_ERR_UND;
2284 goto error;
2285 }
2286
2287 return nb_events;
2288
2289 error:
2290 /* Return negative value to differentiate return code */
2291 return -ret;
2292 }
2293
2294 /*
2295 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2296 */
2297 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2298 struct lttng_event_field **fields)
2299 {
2300 int ret;
2301 ssize_t nb_fields = 0;
2302
2303 switch (domain) {
2304 case LTTNG_DOMAIN_UST:
2305 nb_fields = ust_app_list_event_fields(fields);
2306 if (nb_fields < 0) {
2307 ret = LTTNG_ERR_UST_LIST_FAIL;
2308 goto error;
2309 }
2310 break;
2311 case LTTNG_DOMAIN_KERNEL:
2312 default: /* fall-through */
2313 ret = LTTNG_ERR_UND;
2314 goto error;
2315 }
2316
2317 return nb_fields;
2318
2319 error:
2320 /* Return negative value to differentiate return code */
2321 return -ret;
2322 }
2323
2324 ssize_t cmd_list_syscalls(struct lttng_event **events)
2325 {
2326 return syscall_table_list(events);
2327 }
2328
2329 /*
2330 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2331 *
2332 * Called with session lock held.
2333 */
2334 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2335 enum lttng_domain_type domain, int32_t **pids)
2336 {
2337 int ret;
2338 ssize_t nr_pids = 0;
2339
2340 switch (domain) {
2341 case LTTNG_DOMAIN_KERNEL:
2342 {
2343 struct ltt_kernel_session *ksess;
2344
2345 ksess = session->kernel_session;
2346 nr_pids = kernel_list_tracker_pids(ksess, pids);
2347 if (nr_pids < 0) {
2348 ret = LTTNG_ERR_KERN_LIST_FAIL;
2349 goto error;
2350 }
2351 break;
2352 }
2353 case LTTNG_DOMAIN_UST:
2354 {
2355 struct ltt_ust_session *usess;
2356
2357 usess = session->ust_session;
2358 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2359 if (nr_pids < 0) {
2360 ret = LTTNG_ERR_UST_LIST_FAIL;
2361 goto error;
2362 }
2363 break;
2364 }
2365 case LTTNG_DOMAIN_LOG4J:
2366 case LTTNG_DOMAIN_JUL:
2367 case LTTNG_DOMAIN_PYTHON:
2368 default:
2369 ret = LTTNG_ERR_UND;
2370 goto error;
2371 }
2372
2373 return nr_pids;
2374
2375 error:
2376 /* Return negative value to differentiate return code */
2377 return -ret;
2378 }
2379
2380 static
2381 int domain_mkdir(const struct consumer_output *output,
2382 const struct ltt_session *session,
2383 uid_t uid, gid_t gid)
2384 {
2385 struct consumer_socket *socket;
2386 struct lttng_ht_iter iter;
2387 int ret;
2388 char *path = NULL;
2389
2390 if (!output || !output->socks) {
2391 ERR("No consumer output found");
2392 ret = -1;
2393 goto end;
2394 }
2395
2396 path = zmalloc(LTTNG_PATH_MAX * sizeof(char));
2397 if (!path) {
2398 ERR("Cannot allocate mkdir path");
2399 ret = -1;
2400 goto end;
2401 }
2402
2403 ret = snprintf(path, LTTNG_PATH_MAX, "%s%s%s",
2404 session_get_base_path(session),
2405 output->chunk_path, output->subdir);
2406 if (ret < 0 || ret >= LTTNG_PATH_MAX) {
2407 ERR("Format path");
2408 ret = -1;
2409 goto end;
2410 }
2411
2412 DBG("Domain mkdir %s for session %" PRIu64, path, session->id);
2413 rcu_read_lock();
2414 /*
2415 * We have to iterate to find a socket, but we only need to send the
2416 * rename command to one consumer, so we break after the first one.
2417 */
2418 cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
2419 pthread_mutex_lock(socket->lock);
2420 ret = consumer_mkdir(socket, session->id, output, path, uid, gid);
2421 pthread_mutex_unlock(socket->lock);
2422 if (ret) {
2423 ERR("Consumer mkdir");
2424 ret = -1;
2425 goto end_unlock;
2426 }
2427 break;
2428 }
2429
2430 ret = 0;
2431
2432 end_unlock:
2433 rcu_read_unlock();
2434 end:
2435 free(path);
2436 return ret;
2437 }
2438
2439 static
2440 int session_mkdir(const struct ltt_session *session)
2441 {
2442 int ret;
2443 struct consumer_output *output;
2444 uid_t uid;
2445 gid_t gid;
2446
2447 /*
2448 * Unsupported feature in lttng-relayd before 2.11, not an error since it
2449 * is only needed for session rotation and the user will get an error
2450 * on rotate.
2451 */
2452 if (session->consumer->type == CONSUMER_DST_NET &&
2453 session->consumer->relay_major_version == 2 &&
2454 session->consumer->relay_minor_version < 11) {
2455 ret = 0;
2456 goto end;
2457 }
2458
2459 if (session->kernel_session) {
2460 output = session->kernel_session->consumer;
2461 uid = session->kernel_session->uid;
2462 gid = session->kernel_session->gid;
2463 ret = domain_mkdir(output, session, uid, gid);
2464 if (ret) {
2465 ERR("Mkdir kernel");
2466 goto end;
2467 }
2468 }
2469
2470 if (session->ust_session) {
2471 output = session->ust_session->consumer;
2472 uid = session->ust_session->uid;
2473 gid = session->ust_session->gid;
2474 ret = domain_mkdir(output, session, uid, gid);
2475 if (ret) {
2476 ERR("Mkdir UST");
2477 goto end;
2478 }
2479 }
2480
2481 ret = 0;
2482
2483 end:
2484 return ret;
2485 }
2486
2487 /*
2488 * Command LTTNG_START_TRACE processed by the client thread.
2489 *
2490 * Called with session mutex held.
2491 */
2492 int cmd_start_trace(struct ltt_session *session)
2493 {
2494 int ret;
2495 unsigned long nb_chan = 0;
2496 struct ltt_kernel_session *ksession;
2497 struct ltt_ust_session *usess;
2498
2499 assert(session);
2500
2501 /* Ease our life a bit ;) */
2502 ksession = session->kernel_session;
2503 usess = session->ust_session;
2504
2505 /* Is the session already started? */
2506 if (session->active) {
2507 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2508 goto error;
2509 }
2510
2511 /*
2512 * Starting a session without channel is useless since after that it's not
2513 * possible to enable channel thus inform the client.
2514 */
2515 if (usess && usess->domain_global.channels) {
2516 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2517 }
2518 if (ksession) {
2519 nb_chan += ksession->channel_count;
2520 }
2521 if (!nb_chan) {
2522 ret = LTTNG_ERR_NO_CHANNEL;
2523 goto error;
2524 }
2525
2526 /*
2527 * Record the timestamp of the first time the session is started for
2528 * an eventual session rotation call.
2529 */
2530 if (!session->has_been_started) {
2531 session->current_chunk_start_ts = time(NULL);
2532 if (session->current_chunk_start_ts == (time_t) -1) {
2533 PERROR("Failed to retrieve the \"%s\" session's start time",
2534 session->name);
2535 ret = LTTNG_ERR_FATAL;
2536 goto error;
2537 }
2538 if (!session->snapshot_mode && session->output_traces) {
2539 ret = session_mkdir(session);
2540 if (ret) {
2541 ERR("Failed to create the session directories");
2542 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2543 goto error;
2544 }
2545 }
2546 }
2547
2548 /* Kernel tracing */
2549 if (ksession != NULL) {
2550 DBG("Start kernel tracing session %s", session->name);
2551 ret = start_kernel_session(ksession, kernel_tracer_fd);
2552 if (ret != LTTNG_OK) {
2553 goto error;
2554 }
2555 }
2556
2557 /* Flag session that trace should start automatically */
2558 if (usess) {
2559 /*
2560 * Even though the start trace might fail, flag this session active so
2561 * other application coming in are started by default.
2562 */
2563 usess->active = 1;
2564
2565 ret = ust_app_start_trace_all(usess);
2566 if (ret < 0) {
2567 ret = LTTNG_ERR_UST_START_FAIL;
2568 goto error;
2569 }
2570 }
2571
2572 /* Flag this after a successful start. */
2573 session->has_been_started = 1;
2574 session->active = 1;
2575
2576 /*
2577 * Clear the flag that indicates that a rotation was done while the
2578 * session was stopped.
2579 */
2580 session->rotated_after_last_stop = false;
2581
2582 if (session->rotate_timer_period) {
2583 ret = sessiond_rotate_timer_start(session,
2584 session->rotate_timer_period);
2585 if (ret < 0) {
2586 ERR("Failed to enable rotate timer");
2587 ret = LTTNG_ERR_UNK;
2588 goto error;
2589 }
2590 }
2591
2592 ret = LTTNG_OK;
2593
2594 error:
2595 return ret;
2596 }
2597
2598 static
2599 int rename_active_chunk(struct ltt_session *session)
2600 {
2601 int ret;
2602
2603 session->rotate_count++;
2604
2605 /*
2606 * The currently active tracing path is now the folder we
2607 * want to rename.
2608 */
2609 ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
2610 session->rotation_chunk.active_tracing_path,
2611 sizeof(session->rotation_chunk.current_rotate_path));
2612 if (ret) {
2613 ERR("Failed to copy active tracing path");
2614 goto end;
2615 }
2616
2617 ret = rename_complete_chunk(session, time(NULL));
2618 if (ret < 0) {
2619 ERR("Failed to rename current rotate path");
2620 goto end;
2621 }
2622
2623 /*
2624 * We just renamed, the folder, we didn't do an actual rotation, so
2625 * the active tracing path is now the renamed folder and we have to
2626 * restore the rotate count.
2627 */
2628 ret = lttng_strncpy(session->rotation_chunk.active_tracing_path,
2629 session->rotation_chunk.current_rotate_path,
2630 sizeof(session->rotation_chunk.active_tracing_path));
2631 if (ret) {
2632 ERR("Failed to rename active session chunk tracing path");
2633 goto end;
2634 }
2635 end:
2636 session->rotate_count--;
2637 return ret;
2638 }
2639
2640 /*
2641 * Command LTTNG_STOP_TRACE processed by the client thread.
2642 */
2643 int cmd_stop_trace(struct ltt_session *session)
2644 {
2645 int ret;
2646 struct ltt_kernel_channel *kchan;
2647 struct ltt_kernel_session *ksession;
2648 struct ltt_ust_session *usess;
2649 bool error_occured = false;
2650
2651 assert(session);
2652
2653 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2654 /* Short cut */
2655 ksession = session->kernel_session;
2656 usess = session->ust_session;
2657
2658 /* Session is not active. Skip everythong and inform the client. */
2659 if (!session->active) {
2660 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2661 goto error;
2662 }
2663
2664 if (session->rotate_relay_pending_timer_enabled) {
2665 sessiond_timer_rotate_pending_stop(session);
2666 }
2667
2668 if (session->rotate_timer_enabled) {
2669 sessiond_rotate_timer_stop(session);
2670 }
2671
2672 if (session->rotate_count > 0 && !session->rotate_pending) {
2673 ret = rename_active_chunk(session);
2674 if (ret) {
2675 /*
2676 * This error should not prevent the user from stopping
2677 * the session. However, it will be reported at the end.
2678 */
2679 error_occured = true;
2680 }
2681 }
2682
2683 /* Kernel tracer */
2684 if (ksession && ksession->active) {
2685 DBG("Stop kernel tracing");
2686
2687 ret = kernel_stop_session(ksession);
2688 if (ret < 0) {
2689 ret = LTTNG_ERR_KERN_STOP_FAIL;
2690 goto error;
2691 }
2692
2693 kernel_wait_quiescent(kernel_tracer_fd);
2694
2695 /* Flush metadata after stopping (if exists) */
2696 if (ksession->metadata_stream_fd >= 0) {
2697 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2698 if (ret < 0) {
2699 ERR("Kernel metadata flush failed");
2700 }
2701 }
2702
2703 /* Flush all buffers after stopping */
2704 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2705 ret = kernel_flush_buffer(kchan);
2706 if (ret < 0) {
2707 ERR("Kernel flush buffer error");
2708 }
2709 }
2710
2711 ksession->active = 0;
2712 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2713 session->id);
2714 }
2715
2716 if (usess && usess->active) {
2717 /*
2718 * Even though the stop trace might fail, flag this session inactive so
2719 * other application coming in are not started by default.
2720 */
2721 usess->active = 0;
2722
2723 ret = ust_app_stop_trace_all(usess);
2724 if (ret < 0) {
2725 ret = LTTNG_ERR_UST_STOP_FAIL;
2726 goto error;
2727 }
2728 }
2729
2730 /* Flag inactive after a successful stop. */
2731 session->active = 0;
2732 ret = !error_occured ? LTTNG_OK : LTTNG_ERR_UNK;
2733
2734 error:
2735 return ret;
2736 }
2737
2738 /*
2739 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2740 */
2741 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2742 struct lttng_uri *uris)
2743 {
2744 int ret, i;
2745 struct ltt_kernel_session *ksess = session->kernel_session;
2746 struct ltt_ust_session *usess = session->ust_session;
2747
2748 assert(session);
2749 assert(uris);
2750 assert(nb_uri > 0);
2751
2752 /* Can't set consumer URI if the session is active. */
2753 if (session->active) {
2754 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2755 goto error;
2756 }
2757
2758 /* Set the "global" consumer URIs */
2759 for (i = 0; i < nb_uri; i++) {
2760 ret = add_uri_to_consumer(session->consumer,
2761 &uris[i], 0, session->name);
2762 if (ret != LTTNG_OK) {
2763 goto error;
2764 }
2765 }
2766
2767 /* Set UST session URIs */
2768 if (session->ust_session) {
2769 for (i = 0; i < nb_uri; i++) {
2770 ret = add_uri_to_consumer(
2771 session->ust_session->consumer,
2772 &uris[i], LTTNG_DOMAIN_UST,
2773 session->name);
2774 if (ret != LTTNG_OK) {
2775 goto error;
2776 }
2777 }
2778 }
2779
2780 /* Set kernel session URIs */
2781 if (session->kernel_session) {
2782 for (i = 0; i < nb_uri; i++) {
2783 ret = add_uri_to_consumer(
2784 session->kernel_session->consumer,
2785 &uris[i], LTTNG_DOMAIN_KERNEL,
2786 session->name);
2787 if (ret != LTTNG_OK) {
2788 goto error;
2789 }
2790 }
2791 }
2792
2793 /*
2794 * Make sure to set the session in output mode after we set URI since a
2795 * session can be created without URL (thus flagged in no output mode).
2796 */
2797 session->output_traces = 1;
2798 if (ksess) {
2799 ksess->output_traces = 1;
2800 }
2801
2802 if (usess) {
2803 usess->output_traces = 1;
2804 }
2805
2806 /* All good! */
2807 ret = LTTNG_OK;
2808
2809 error:
2810 return ret;
2811 }
2812
2813 /*
2814 * Command LTTNG_CREATE_SESSION processed by the client thread.
2815 */
2816 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
2817 size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
2818 {
2819 int ret;
2820 struct ltt_session *session;
2821
2822 assert(name);
2823 assert(creds);
2824
2825 /*
2826 * Verify if the session already exist
2827 *
2828 * XXX: There is no need for the session lock list here since the caller
2829 * (process_client_msg) is holding it. We might want to change that so a
2830 * single command does not lock the entire session list.
2831 */
2832 session = session_find_by_name(name);
2833 if (session != NULL) {
2834 ret = LTTNG_ERR_EXIST_SESS;
2835 goto find_error;
2836 }
2837
2838 /* Create tracing session in the registry */
2839 ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
2840 LTTNG_SOCK_GET_GID_CRED(creds));
2841 if (ret != LTTNG_OK) {
2842 goto session_error;
2843 }
2844
2845 /*
2846 * Get the newly created session pointer back
2847 *
2848 * XXX: There is no need for the session lock list here since the caller
2849 * (process_client_msg) is holding it. We might want to change that so a
2850 * single command does not lock the entire session list.
2851 */
2852 session = session_find_by_name(name);
2853 assert(session);
2854
2855 session->live_timer = live_timer;
2856 /* Create default consumer output for the session not yet created. */
2857 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
2858 if (session->consumer == NULL) {
2859 ret = LTTNG_ERR_FATAL;
2860 goto consumer_error;
2861 }
2862
2863 if (uris) {
2864 ret = cmd_set_consumer_uri(session, nb_uri, uris);
2865 if (ret != LTTNG_OK) {
2866 goto consumer_error;
2867 }
2868 session->output_traces = 1;
2869 } else {
2870 session->output_traces = 0;
2871 DBG2("Session %s created with no output", session->name);
2872 }
2873
2874 session->consumer->enabled = 1;
2875
2876 return LTTNG_OK;
2877
2878 consumer_error:
2879 session_destroy(session);
2880 session_error:
2881 find_error:
2882 return ret;
2883 }
2884
2885 /*
2886 * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
2887 */
2888 int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
2889 size_t nb_uri, lttng_sock_cred *creds)
2890 {
2891 int ret;
2892 struct ltt_session *session;
2893 struct snapshot_output *new_output = NULL;
2894
2895 assert(name);
2896 assert(creds);
2897
2898 /*
2899 * Create session in no output mode with URIs set to NULL. The uris we've
2900 * received are for a default snapshot output if one.
2901 */
2902 ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
2903 if (ret != LTTNG_OK) {
2904 goto error;
2905 }
2906
2907 /* Get the newly created session pointer back. This should NEVER fail. */
2908 session = session_find_by_name(name);
2909 assert(session);
2910
2911 /* Flag session for snapshot mode. */
2912 session->snapshot_mode = 1;
2913
2914 /* Skip snapshot output creation if no URI is given. */
2915 if (nb_uri == 0) {
2916 goto end;
2917 }
2918
2919 new_output = snapshot_output_alloc();
2920 if (!new_output) {
2921 ret = LTTNG_ERR_NOMEM;
2922 goto error_snapshot_alloc;
2923 }
2924
2925 ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
2926 uris, nb_uri, session->consumer, new_output, &session->snapshot);
2927 if (ret < 0) {
2928 if (ret == -ENOMEM) {
2929 ret = LTTNG_ERR_NOMEM;
2930 } else {
2931 ret = LTTNG_ERR_INVALID;
2932 }
2933 goto error_snapshot;
2934 }
2935
2936 rcu_read_lock();
2937 snapshot_add_output(&session->snapshot, new_output);
2938 rcu_read_unlock();
2939
2940 end:
2941 return LTTNG_OK;
2942
2943 error_snapshot:
2944 snapshot_output_destroy(new_output);
2945 error_snapshot_alloc:
2946 session_destroy(session);
2947 error:
2948 return ret;
2949 }
2950
2951 /*
2952 * Command LTTNG_DESTROY_SESSION processed by the client thread.
2953 *
2954 * Called with session lock held.
2955 */
2956 int cmd_destroy_session(struct ltt_session *session, int wpipe,
2957 struct notification_thread_handle *notification_thread_handle)
2958 {
2959 int ret;
2960 struct ltt_ust_session *usess;
2961 struct ltt_kernel_session *ksess;
2962
2963 /* Safety net */
2964 assert(session);
2965
2966 usess = session->ust_session;
2967 ksess = session->kernel_session;
2968
2969 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
2970
2971 if (session->rotate_relay_pending_timer_enabled) {
2972 sessiond_timer_rotate_pending_stop(session);
2973 }
2974
2975 if (session->rotate_timer_enabled) {
2976 sessiond_rotate_timer_stop(session);
2977 }
2978
2979 if (session->rotate_size) {
2980 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
2981 session->rotate_size = 0;
2982 }
2983
2984 /*
2985 * The rename of the current chunk is performed at stop, but if we rotated
2986 * the session after the previous stop command, we need to rename the
2987 * new (and empty) chunk that was started in between.
2988 */
2989 if (session->rotated_after_last_stop) {
2990 rename_active_chunk(session);
2991 }
2992
2993 /* Clean kernel session teardown */
2994 kernel_destroy_session(ksess);
2995
2996 /* UST session teardown */
2997 if (usess) {
2998 /* Close any relayd session */
2999 consumer_output_send_destroy_relayd(usess->consumer);
3000
3001 /* Destroy every UST application related to this session. */
3002 ret = ust_app_destroy_trace_all(usess);
3003 if (ret) {
3004 ERR("Error in ust_app_destroy_trace_all");
3005 }
3006
3007 /* Clean up the rest. */
3008 trace_ust_destroy_session(usess);
3009 }
3010
3011 /*
3012 * Must notify the kernel thread here to update it's poll set in order to
3013 * remove the channel(s)' fd just destroyed.
3014 */
3015 ret = notify_thread_pipe(wpipe);
3016 if (ret < 0) {
3017 PERROR("write kernel poll pipe");
3018 }
3019
3020 ret = session_destroy(session);
3021
3022 return ret;
3023 }
3024
3025 /*
3026 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3027 */
3028 int cmd_register_consumer(struct ltt_session *session,
3029 enum lttng_domain_type domain, const char *sock_path,
3030 struct consumer_data *cdata)
3031 {
3032 int ret, sock;
3033 struct consumer_socket *socket = NULL;
3034
3035 assert(session);
3036 assert(cdata);
3037 assert(sock_path);
3038
3039 switch (domain) {
3040 case LTTNG_DOMAIN_KERNEL:
3041 {
3042 struct ltt_kernel_session *ksess = session->kernel_session;
3043
3044 assert(ksess);
3045
3046 /* Can't register a consumer if there is already one */
3047 if (ksess->consumer_fds_sent != 0) {
3048 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3049 goto error;
3050 }
3051
3052 sock = lttcomm_connect_unix_sock(sock_path);
3053 if (sock < 0) {
3054 ret = LTTNG_ERR_CONNECT_FAIL;
3055 goto error;
3056 }
3057 cdata->cmd_sock = sock;
3058
3059 socket = consumer_allocate_socket(&cdata->cmd_sock);
3060 if (socket == NULL) {
3061 ret = close(sock);
3062 if (ret < 0) {
3063 PERROR("close register consumer");
3064 }
3065 cdata->cmd_sock = -1;
3066 ret = LTTNG_ERR_FATAL;
3067 goto error;
3068 }
3069
3070 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3071 if (socket->lock == NULL) {
3072 PERROR("zmalloc pthread mutex");
3073 ret = LTTNG_ERR_FATAL;
3074 goto error;
3075 }
3076 pthread_mutex_init(socket->lock, NULL);
3077 socket->registered = 1;
3078
3079 rcu_read_lock();
3080 consumer_add_socket(socket, ksess->consumer);
3081 rcu_read_unlock();
3082
3083 pthread_mutex_lock(&cdata->pid_mutex);
3084 cdata->pid = -1;
3085 pthread_mutex_unlock(&cdata->pid_mutex);
3086
3087 break;
3088 }
3089 default:
3090 /* TODO: Userspace tracing */
3091 ret = LTTNG_ERR_UND;
3092 goto error;
3093 }
3094
3095 return LTTNG_OK;
3096
3097 error:
3098 if (socket) {
3099 consumer_destroy_socket(socket);
3100 }
3101 return ret;
3102 }
3103
3104 /*
3105 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3106 */
3107 ssize_t cmd_list_domains(struct ltt_session *session,
3108 struct lttng_domain **domains)
3109 {
3110 int ret, index = 0;
3111 ssize_t nb_dom = 0;
3112 struct agent *agt;
3113 struct lttng_ht_iter iter;
3114
3115 if (session->kernel_session != NULL) {
3116 DBG3("Listing domains found kernel domain");
3117 nb_dom++;
3118 }
3119
3120 if (session->ust_session != NULL) {
3121 DBG3("Listing domains found UST global domain");
3122 nb_dom++;
3123
3124 rcu_read_lock();
3125 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3126 agt, node.node) {
3127 if (agt->being_used) {
3128 nb_dom++;
3129 }
3130 }
3131 rcu_read_unlock();
3132 }
3133
3134 if (!nb_dom) {
3135 goto end;
3136 }
3137
3138 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3139 if (*domains == NULL) {
3140 ret = LTTNG_ERR_FATAL;
3141 goto error;
3142 }
3143
3144 if (session->kernel_session != NULL) {
3145 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3146
3147 /* Kernel session buffer type is always GLOBAL */
3148 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3149
3150 index++;
3151 }
3152
3153 if (session->ust_session != NULL) {
3154 (*domains)[index].type = LTTNG_DOMAIN_UST;
3155 (*domains)[index].buf_type = session->ust_session->buffer_type;
3156 index++;
3157
3158 rcu_read_lock();
3159 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3160 agt, node.node) {
3161 if (agt->being_used) {
3162 (*domains)[index].type = agt->domain;
3163 (*domains)[index].buf_type = session->ust_session->buffer_type;
3164 index++;
3165 }
3166 }
3167 rcu_read_unlock();
3168 }
3169 end:
3170 return nb_dom;
3171
3172 error:
3173 /* Return negative value to differentiate return code */
3174 return -ret;
3175 }
3176
3177
3178 /*
3179 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3180 */
3181 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3182 struct ltt_session *session, struct lttng_channel **channels)
3183 {
3184 ssize_t nb_chan = 0, payload_size = 0, ret;
3185
3186 switch (domain) {
3187 case LTTNG_DOMAIN_KERNEL:
3188 if (session->kernel_session != NULL) {
3189 nb_chan = session->kernel_session->channel_count;
3190 }
3191 DBG3("Number of kernel channels %zd", nb_chan);
3192 if (nb_chan <= 0) {
3193 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3194 goto end;
3195 }
3196 break;
3197 case LTTNG_DOMAIN_UST:
3198 if (session->ust_session != NULL) {
3199 rcu_read_lock();
3200 nb_chan = lttng_ht_get_count(
3201 session->ust_session->domain_global.channels);
3202 rcu_read_unlock();
3203 }
3204 DBG3("Number of UST global channels %zd", nb_chan);
3205 if (nb_chan < 0) {
3206 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3207 goto end;
3208 }
3209 break;
3210 default:
3211 ret = -LTTNG_ERR_UND;
3212 goto end;
3213 }
3214
3215 if (nb_chan > 0) {
3216 const size_t channel_size = sizeof(struct lttng_channel) +
3217 sizeof(struct lttng_channel_extended);
3218 struct lttng_channel_extended *channel_exts;
3219
3220 payload_size = nb_chan * channel_size;
3221 *channels = zmalloc(payload_size);
3222 if (*channels == NULL) {
3223 ret = -LTTNG_ERR_FATAL;
3224 goto end;
3225 }
3226
3227 channel_exts = ((void *) *channels) +
3228 (nb_chan * sizeof(struct lttng_channel));
3229 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3230 if (ret != LTTNG_OK) {
3231 free(*channels);
3232 *channels = NULL;
3233 goto end;
3234 }
3235 } else {
3236 *channels = NULL;
3237 }
3238
3239 ret = payload_size;
3240 end:
3241 return ret;
3242 }
3243
3244 /*
3245 * Command LTTNG_LIST_EVENTS processed by the client thread.
3246 */
3247 ssize_t cmd_list_events(enum lttng_domain_type domain,
3248 struct ltt_session *session, char *channel_name,
3249 struct lttng_event **events, size_t *total_size)
3250 {
3251 int ret = 0;
3252 ssize_t nb_event = 0;
3253
3254 switch (domain) {
3255 case LTTNG_DOMAIN_KERNEL:
3256 if (session->kernel_session != NULL) {
3257 nb_event = list_lttng_kernel_events(channel_name,
3258 session->kernel_session, events,
3259 total_size);
3260 }
3261 break;
3262 case LTTNG_DOMAIN_UST:
3263 {
3264 if (session->ust_session != NULL) {
3265 nb_event = list_lttng_ust_global_events(channel_name,
3266 &session->ust_session->domain_global, events,
3267 total_size);
3268 }
3269 break;
3270 }
3271 case LTTNG_DOMAIN_LOG4J:
3272 case LTTNG_DOMAIN_JUL:
3273 case LTTNG_DOMAIN_PYTHON:
3274 if (session->ust_session) {
3275 struct lttng_ht_iter iter;
3276 struct agent *agt;
3277
3278 rcu_read_lock();
3279 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3280 &iter.iter, agt, node.node) {
3281 if (agt->domain == domain) {
3282 nb_event = list_lttng_agent_events(
3283 agt, events,
3284 total_size);
3285 break;
3286 }
3287 }
3288 rcu_read_unlock();
3289 }
3290 break;
3291 default:
3292 ret = LTTNG_ERR_UND;
3293 goto error;
3294 }
3295
3296 return nb_event;
3297
3298 error:
3299 /* Return negative value to differentiate return code */
3300 return -ret;
3301 }
3302
3303 /*
3304 * Using the session list, filled a lttng_session array to send back to the
3305 * client for session listing.
3306 *
3307 * The session list lock MUST be acquired before calling this function. Use
3308 * session_lock_list() and session_unlock_list().
3309 */
3310 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
3311 gid_t gid)
3312 {
3313 int ret;
3314 unsigned int i = 0;
3315 struct ltt_session *session;
3316 struct ltt_session_list *list = session_get_list();
3317
3318 DBG("Getting all available session for UID %d GID %d",
3319 uid, gid);
3320 /*
3321 * Iterate over session list and append data after the control struct in
3322 * the buffer.
3323 */
3324 cds_list_for_each_entry(session, &list->head, list) {
3325 /*
3326 * Only list the sessions the user can control.
3327 */
3328 if (!session_access_ok(session, uid, gid)) {
3329 continue;
3330 }
3331
3332 struct ltt_kernel_session *ksess = session->kernel_session;
3333 struct ltt_ust_session *usess = session->ust_session;
3334
3335 if (session->consumer->type == CONSUMER_DST_NET ||
3336 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3337 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3338 ret = build_network_session_path(sessions[i].path,
3339 sizeof(sessions[i].path), session);
3340 } else {
3341 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3342 session->consumer->dst.session_root_path);
3343 }
3344 if (ret < 0) {
3345 PERROR("snprintf session path");
3346 continue;
3347 }
3348
3349 strncpy(sessions[i].name, session->name, NAME_MAX);
3350 sessions[i].name[NAME_MAX - 1] = '\0';
3351 sessions[i].enabled = session->active;
3352 sessions[i].snapshot_mode = session->snapshot_mode;
3353 sessions[i].live_timer_interval = session->live_timer;
3354 i++;
3355 }
3356 }
3357
3358 /*
3359 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3360 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3361 */
3362 int cmd_data_pending(struct ltt_session *session)
3363 {
3364 int ret;
3365 struct ltt_kernel_session *ksess = session->kernel_session;
3366 struct ltt_ust_session *usess = session->ust_session;
3367
3368 assert(session);
3369
3370 DBG("Data pending for session %s", session->name);
3371
3372 /* Session MUST be stopped to ask for data availability. */
3373 if (session->active) {
3374 ret = LTTNG_ERR_SESSION_STARTED;
3375 goto error;
3376 } else {
3377 /*
3378 * If stopped, just make sure we've started before else the above call
3379 * will always send that there is data pending.
3380 *
3381 * The consumer assumes that when the data pending command is received,
3382 * the trace has been started before or else no output data is written
3383 * by the streams which is a condition for data pending. So, this is
3384 * *VERY* important that we don't ask the consumer before a start
3385 * trace.
3386 */
3387 if (!session->has_been_started) {
3388 ret = 0;
3389 goto error;
3390 }
3391 }
3392
3393 /*
3394 * A rotation is still pending, we have to wait.
3395 */
3396 if (session->rotate_pending) {
3397 DBG("Rotate still pending for session %s", session->name);
3398 ret = 1;
3399 goto error;
3400 }
3401
3402 if (ksess && ksess->consumer) {
3403 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3404 if (ret == 1) {
3405 /* Data is still being extracted for the kernel. */
3406 goto error;
3407 }
3408 }
3409
3410 if (usess && usess->consumer) {
3411 ret = consumer_is_data_pending(usess->id, usess->consumer);
3412 if (ret == 1) {
3413 /* Data is still being extracted for the kernel. */
3414 goto error;
3415 }
3416 }
3417
3418 /* Data is ready to be read by a viewer */
3419 ret = 0;
3420
3421 error:
3422 return ret;
3423 }
3424
3425 /*
3426 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3427 *
3428 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3429 */
3430 int cmd_snapshot_add_output(struct ltt_session *session,
3431 struct lttng_snapshot_output *output, uint32_t *id)
3432 {
3433 int ret;
3434 struct snapshot_output *new_output;
3435
3436 assert(session);
3437 assert(output);
3438
3439 DBG("Cmd snapshot add output for session %s", session->name);
3440
3441 /*
3442 * Can't create an output if the session is not set in no-output mode.
3443 */
3444 if (session->output_traces) {
3445 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3446 goto error;
3447 }
3448
3449 /* Only one output is allowed until we have the "tee" feature. */
3450 if (session->snapshot.nb_output == 1) {
3451 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3452 goto error;
3453 }
3454
3455 new_output = snapshot_output_alloc();
3456 if (!new_output) {
3457 ret = LTTNG_ERR_NOMEM;
3458 goto error;
3459 }
3460
3461 ret = snapshot_output_init(output->max_size, output->name,
3462 output->ctrl_url, output->data_url, session->consumer, new_output,
3463 &session->snapshot);
3464 if (ret < 0) {
3465 if (ret == -ENOMEM) {
3466 ret = LTTNG_ERR_NOMEM;
3467 } else {
3468 ret = LTTNG_ERR_INVALID;
3469 }
3470 goto free_error;
3471 }
3472
3473 rcu_read_lock();
3474 snapshot_add_output(&session->snapshot, new_output);
3475 if (id) {
3476 *id = new_output->id;
3477 }
3478 rcu_read_unlock();
3479
3480 return LTTNG_OK;
3481
3482 free_error:
3483 snapshot_output_destroy(new_output);
3484 error:
3485 return ret;
3486 }
3487
3488 /*
3489 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3490 *
3491 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3492 */
3493 int cmd_snapshot_del_output(struct ltt_session *session,
3494 struct lttng_snapshot_output *output)
3495 {
3496 int ret;
3497 struct snapshot_output *sout = NULL;
3498
3499 assert(session);
3500 assert(output);
3501
3502 rcu_read_lock();
3503
3504 /*
3505 * Permission denied to create an output if the session is not
3506 * set in no output mode.
3507 */
3508 if (session->output_traces) {
3509 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3510 goto error;
3511 }
3512
3513 if (output->id) {
3514 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3515 session->name);
3516 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3517 } else if (*output->name != '\0') {
3518 DBG("Cmd snapshot del output name %s for session %s", output->name,
3519 session->name);
3520 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3521 }
3522 if (!sout) {
3523 ret = LTTNG_ERR_INVALID;
3524 goto error;
3525 }
3526
3527 snapshot_delete_output(&session->snapshot, sout);
3528 snapshot_output_destroy(sout);
3529 ret = LTTNG_OK;
3530
3531 error:
3532 rcu_read_unlock();
3533 return ret;
3534 }
3535
3536 /*
3537 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3538 *
3539 * If no output is available, outputs is untouched and 0 is returned.
3540 *
3541 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3542 */
3543 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3544 struct lttng_snapshot_output **outputs)
3545 {
3546 int ret, idx = 0;
3547 struct lttng_snapshot_output *list = NULL;
3548 struct lttng_ht_iter iter;
3549 struct snapshot_output *output;
3550
3551 assert(session);
3552 assert(outputs);
3553
3554 DBG("Cmd snapshot list outputs for session %s", session->name);
3555
3556 /*
3557 * Permission denied to create an output if the session is not
3558 * set in no output mode.
3559 */
3560 if (session->output_traces) {
3561 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3562 goto end;
3563 }
3564
3565 if (session->snapshot.nb_output == 0) {
3566 ret = 0;
3567 goto end;
3568 }
3569
3570 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3571 if (!list) {
3572 ret = -LTTNG_ERR_NOMEM;
3573 goto end;
3574 }
3575
3576 /* Copy list from session to the new list object. */
3577 rcu_read_lock();
3578 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3579 output, node.node) {
3580 assert(output->consumer);
3581 list[idx].id = output->id;
3582 list[idx].max_size = output->max_size;
3583 if (lttng_strncpy(list[idx].name, output->name,
3584 sizeof(list[idx].name))) {
3585 ret = -LTTNG_ERR_INVALID;
3586 goto error;
3587 }
3588 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3589 if (lttng_strncpy(list[idx].ctrl_url,
3590 output->consumer->dst.session_root_path,
3591 sizeof(list[idx].ctrl_url))) {
3592 ret = -LTTNG_ERR_INVALID;
3593 goto error;
3594 }
3595 } else {
3596 /* Control URI. */
3597 ret = uri_to_str_url(&output->consumer->dst.net.control,
3598 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3599 if (ret < 0) {
3600 ret = -LTTNG_ERR_NOMEM;
3601 goto error;
3602 }
3603
3604 /* Data URI. */
3605 ret = uri_to_str_url(&output->consumer->dst.net.data,
3606 list[idx].data_url, sizeof(list[idx].data_url));
3607 if (ret < 0) {
3608 ret = -LTTNG_ERR_NOMEM;
3609 goto error;
3610 }
3611 }
3612 idx++;
3613 }
3614
3615 *outputs = list;
3616 list = NULL;
3617 ret = session->snapshot.nb_output;
3618 error:
3619 rcu_read_unlock();
3620 free(list);
3621 end:
3622 return ret;
3623 }
3624
3625 /*
3626 * Check if we can regenerate the metadata for this session.
3627 * Only kernel, UST per-uid and non-live sessions are supported.
3628 *
3629 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3630 */
3631 static
3632 int check_regenerate_metadata_support(struct ltt_session *session)
3633 {
3634 int ret;
3635
3636 assert(session);
3637
3638 if (session->live_timer != 0) {
3639 ret = LTTNG_ERR_LIVE_SESSION;
3640 goto end;
3641 }
3642 if (!session->active) {
3643 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3644 goto end;
3645 }
3646 if (session->ust_session) {
3647 switch (session->ust_session->buffer_type) {
3648 case LTTNG_BUFFER_PER_UID:
3649 break;
3650 case LTTNG_BUFFER_PER_PID:
3651 ret = LTTNG_ERR_PER_PID_SESSION;
3652 goto end;
3653 default:
3654 assert(0);
3655 ret = LTTNG_ERR_UNK;
3656 goto end;
3657 }
3658 }
3659 if (session->consumer->type == CONSUMER_DST_NET &&
3660 session->consumer->relay_minor_version < 8) {
3661 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
3662 goto end;
3663 }
3664 ret = 0;
3665
3666 end:
3667 return ret;
3668 }
3669
3670 static
3671 int clear_metadata_file(int fd)
3672 {
3673 int ret;
3674
3675 ret = lseek(fd, 0, SEEK_SET);
3676 if (ret < 0) {
3677 PERROR("lseek");
3678 goto end;
3679 }
3680
3681 ret = ftruncate(fd, 0);
3682 if (ret < 0) {
3683 PERROR("ftruncate");
3684 goto end;
3685 }
3686
3687 end:
3688 return ret;
3689 }
3690
3691 static
3692 int ust_regenerate_metadata(struct ltt_ust_session *usess)
3693 {
3694 int ret = 0;
3695 struct buffer_reg_uid *uid_reg = NULL;
3696 struct buffer_reg_session *session_reg = NULL;
3697
3698 rcu_read_lock();
3699 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
3700 struct ust_registry_session *registry;
3701 struct ust_registry_channel *chan;
3702 struct lttng_ht_iter iter_chan;
3703
3704 session_reg = uid_reg->registry;
3705 registry = session_reg->reg.ust;
3706
3707 pthread_mutex_lock(&registry->lock);
3708 registry->metadata_len_sent = 0;
3709 memset(registry->metadata, 0, registry->metadata_alloc_len);
3710 registry->metadata_len = 0;
3711 registry->metadata_version++;
3712 if (registry->metadata_fd > 0) {
3713 /* Clear the metadata file's content. */
3714 ret = clear_metadata_file(registry->metadata_fd);
3715 if (ret) {
3716 pthread_mutex_unlock(&registry->lock);
3717 goto end;
3718 }
3719 }
3720
3721 ret = ust_metadata_session_statedump(registry, NULL,
3722 registry->major, registry->minor);
3723 if (ret) {
3724 pthread_mutex_unlock(&registry->lock);
3725 ERR("Failed to generate session metadata (err = %d)",
3726 ret);
3727 goto end;
3728 }
3729 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
3730 chan, node.node) {
3731 struct ust_registry_event *event;
3732 struct lttng_ht_iter iter_event;
3733
3734 ret = ust_metadata_channel_statedump(registry, chan);
3735 if (ret) {
3736 pthread_mutex_unlock(&registry->lock);
3737 ERR("Failed to generate channel metadata "
3738 "(err = %d)", ret);
3739 goto end;
3740 }
3741 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
3742 event, node.node) {
3743 ret = ust_metadata_event_statedump(registry,
3744 chan, event);
3745 if (ret) {
3746 pthread_mutex_unlock(&registry->lock);
3747 ERR("Failed to generate event metadata "
3748 "(err = %d)", ret);
3749 goto end;
3750 }
3751 }
3752 }
3753 pthread_mutex_unlock(&registry->lock);
3754 }
3755
3756 end:
3757 rcu_read_unlock();
3758 return ret;
3759 }
3760
3761 /*
3762 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
3763 *
3764 * Ask the consumer to truncate the existing metadata file(s) and
3765 * then regenerate the metadata. Live and per-pid sessions are not
3766 * supported and return an error.
3767 *
3768 * Return 0 on success or else a LTTNG_ERR code.
3769 */
3770 int cmd_regenerate_metadata(struct ltt_session *session)
3771 {
3772 int ret;
3773
3774 assert(session);
3775
3776 ret = check_regenerate_metadata_support(session);
3777 if (ret) {
3778 goto end;
3779 }
3780
3781 if (session->kernel_session) {
3782 ret = kernctl_session_regenerate_metadata(
3783 session->kernel_session->fd);
3784 if (ret < 0) {
3785 ERR("Failed to regenerate the kernel metadata");
3786 goto end;
3787 }
3788 }
3789
3790 if (session->ust_session) {
3791 ret = ust_regenerate_metadata(session->ust_session);
3792 if (ret &