0d860236e201551a8389969359e85b1caf133eaa
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25
26 #include <common/defaults.h>
27 #include <common/common.h>
28 #include <common/sessiond-comm/sessiond-comm.h>
29 #include <common/relayd/relayd.h>
30 #include <common/utils.h>
31 #include <common/compat/string.h>
32 #include <common/kernel-ctl/kernel-ctl.h>
33 #include <common/dynamic-buffer.h>
34 #include <common/buffer-view.h>
35 #include <lttng/trigger/trigger-internal.h>
36 #include <lttng/condition/condition.h>
37 #include <lttng/action/action.h>
38 #include <lttng/channel.h>
39 #include <lttng/channel-internal.h>
40 #include <lttng/rotate-internal.h>
41 #include <lttng/location-internal.h>
42 #include <lttng/userspace-probe-internal.h>
43 #include <common/string-utils/string-utils.h>
44
45 #include "channel.h"
46 #include "consumer.h"
47 #include "event.h"
48 #include "health-sessiond.h"
49 #include "kernel.h"
50 #include "kernel-consumer.h"
51 #include "lttng-sessiond.h"
52 #include "utils.h"
53 #include "lttng-syscall.h"
54 #include "agent.h"
55 #include "buffer-registry.h"
56 #include "notification-thread.h"
57 #include "notification-thread-commands.h"
58 #include "rotate.h"
59 #include "rotation-thread.h"
60 #include "sessiond-timer.h"
61 #include "agent-thread.h"
62
63 #include "cmd.h"
64
65 /* Sleep for 100ms between each check for the shm path's deletion. */
66 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
67
68 static enum lttng_error_code wait_on_path(void *path);
69
70 /*
71 * Command completion handler that is used by the destroy command
72 * when a session that has a non-default shm_path is being destroyed.
73 *
74 * See comment in cmd_destroy_session() for the rationale.
75 */
76 static struct destroy_completion_handler {
77 struct cmd_completion_handler handler;
78 char shm_path[member_sizeof(struct ltt_session, shm_path)];
79 } destroy_completion_handler = {
80 .handler = {
81 .run = wait_on_path,
82 .data = destroy_completion_handler.shm_path
83 },
84 .shm_path = { 0 },
85 };
86
87 static struct cmd_completion_handler *current_completion_handler;
88
89 /*
90 * Used to keep a unique index for each relayd socket created where this value
91 * is associated with streams on the consumer so it can match the right relayd
92 * to send to. It must be accessed with the relayd_net_seq_idx_lock
93 * held.
94 */
95 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
96 static uint64_t relayd_net_seq_idx;
97
98 static int validate_ust_event_name(const char *);
99 static int cmd_enable_event_internal(struct ltt_session *session,
100 struct lttng_domain *domain,
101 char *channel_name, struct lttng_event *event,
102 char *filter_expression,
103 struct lttng_filter_bytecode *filter,
104 struct lttng_event_exclusion *exclusion,
105 int wpipe);
106
107 /*
108 * Create a session path used by list_lttng_sessions for the case that the
109 * session consumer is on the network.
110 */
111 static int build_network_session_path(char *dst, size_t size,
112 struct ltt_session *session)
113 {
114 int ret, kdata_port, udata_port;
115 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
116 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
117
118 assert(session);
119 assert(dst);
120
121 memset(tmp_urls, 0, sizeof(tmp_urls));
122 memset(tmp_uurl, 0, sizeof(tmp_uurl));
123
124 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
125
126 if (session->kernel_session && session->kernel_session->consumer) {
127 kuri = &session->kernel_session->consumer->dst.net.control;
128 kdata_port = session->kernel_session->consumer->dst.net.data.port;
129 }
130
131 if (session->ust_session && session->ust_session->consumer) {
132 uuri = &session->ust_session->consumer->dst.net.control;
133 udata_port = session->ust_session->consumer->dst.net.data.port;
134 }
135
136 if (uuri == NULL && kuri == NULL) {
137 uri = &session->consumer->dst.net.control;
138 kdata_port = session->consumer->dst.net.data.port;
139 } else if (kuri && uuri) {
140 ret = uri_compare(kuri, uuri);
141 if (ret) {
142 /* Not Equal */
143 uri = kuri;
144 /* Build uuri URL string */
145 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
146 if (ret < 0) {
147 goto error;
148 }
149 } else {
150 uri = kuri;
151 }
152 } else if (kuri && uuri == NULL) {
153 uri = kuri;
154 } else if (uuri && kuri == NULL) {
155 uri = uuri;
156 }
157
158 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
159 if (ret < 0) {
160 goto error;
161 }
162
163 /*
164 * Do we have a UST url set. If yes, this means we have both kernel and UST
165 * to print.
166 */
167 if (*tmp_uurl != '\0') {
168 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
169 tmp_urls, kdata_port, tmp_uurl, udata_port);
170 } else {
171 int dport;
172 if (kuri || (!kuri && !uuri)) {
173 dport = kdata_port;
174 } else {
175 /* No kernel URI, use the UST port. */
176 dport = udata_port;
177 }
178 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
179 }
180
181 error:
182 return ret;
183 }
184
185 /*
186 * Get run-time attributes if the session has been started (discarded events,
187 * lost packets).
188 */
189 static int get_kernel_runtime_stats(struct ltt_session *session,
190 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
191 uint64_t *lost_packets)
192 {
193 int ret;
194
195 if (!session->has_been_started) {
196 ret = 0;
197 *discarded_events = 0;
198 *lost_packets = 0;
199 goto end;
200 }
201
202 ret = consumer_get_discarded_events(session->id, kchan->key,
203 session->kernel_session->consumer,
204 discarded_events);
205 if (ret < 0) {
206 goto end;
207 }
208
209 ret = consumer_get_lost_packets(session->id, kchan->key,
210 session->kernel_session->consumer,
211 lost_packets);
212 if (ret < 0) {
213 goto end;
214 }
215
216 end:
217 return ret;
218 }
219
220 /*
221 * Get run-time attributes if the session has been started (discarded events,
222 * lost packets).
223 */
224 static int get_ust_runtime_stats(struct ltt_session *session,
225 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
226 uint64_t *lost_packets)
227 {
228 int ret;
229 struct ltt_ust_session *usess;
230
231 if (!discarded_events || !lost_packets) {
232 ret = -1;
233 goto end;
234 }
235
236 usess = session->ust_session;
237 assert(discarded_events);
238 assert(lost_packets);
239
240 if (!usess || !session->has_been_started) {
241 *discarded_events = 0;
242 *lost_packets = 0;
243 ret = 0;
244 goto end;
245 }
246
247 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
248 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
249 &usess->buffer_reg_uid_list,
250 usess->consumer, uchan->id,
251 uchan->attr.overwrite,
252 discarded_events,
253 lost_packets);
254 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
255 ret = ust_app_pid_get_channel_runtime_stats(usess,
256 uchan, usess->consumer,
257 uchan->attr.overwrite,
258 discarded_events,
259 lost_packets);
260 if (ret < 0) {
261 goto end;
262 }
263 *discarded_events += uchan->per_pid_closed_app_discarded;
264 *lost_packets += uchan->per_pid_closed_app_lost;
265 } else {
266 ERR("Unsupported buffer type");
267 assert(0);
268 ret = -1;
269 goto end;
270 }
271
272 end:
273 return ret;
274 }
275
276 /*
277 * Fill lttng_channel array of all channels.
278 */
279 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
280 struct ltt_session *session, struct lttng_channel *channels,
281 struct lttng_channel_extended *chan_exts)
282 {
283 int i = 0, ret = 0;
284 struct ltt_kernel_channel *kchan;
285
286 DBG("Listing channels for session %s", session->name);
287
288 switch (domain) {
289 case LTTNG_DOMAIN_KERNEL:
290 /* Kernel channels */
291 if (session->kernel_session != NULL) {
292 cds_list_for_each_entry(kchan,
293 &session->kernel_session->channel_list.head, list) {
294 uint64_t discarded_events, lost_packets;
295 struct lttng_channel_extended *extended;
296
297 extended = (struct lttng_channel_extended *)
298 kchan->channel->attr.extended.ptr;
299
300 ret = get_kernel_runtime_stats(session, kchan,
301 &discarded_events, &lost_packets);
302 if (ret < 0) {
303 goto end;
304 }
305 /* Copy lttng_channel struct to array */
306 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
307 channels[i].enabled = kchan->enabled;
308 chan_exts[i].discarded_events =
309 discarded_events;
310 chan_exts[i].lost_packets = lost_packets;
311 chan_exts[i].monitor_timer_interval =
312 extended->monitor_timer_interval;
313 chan_exts[i].blocking_timeout = 0;
314 i++;
315 }
316 }
317 break;
318 case LTTNG_DOMAIN_UST:
319 {
320 struct lttng_ht_iter iter;
321 struct ltt_ust_channel *uchan;
322
323 rcu_read_lock();
324 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
325 &iter.iter, uchan, node.node) {
326 uint64_t discarded_events = 0, lost_packets = 0;
327
328 if (lttng_strncpy(channels[i].name, uchan->name,
329 LTTNG_SYMBOL_NAME_LEN)) {
330 break;
331 }
332 channels[i].attr.overwrite = uchan->attr.overwrite;
333 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
334 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
335 channels[i].attr.switch_timer_interval =
336 uchan->attr.switch_timer_interval;
337 channels[i].attr.read_timer_interval =
338 uchan->attr.read_timer_interval;
339 channels[i].enabled = uchan->enabled;
340 channels[i].attr.tracefile_size = uchan->tracefile_size;
341 channels[i].attr.tracefile_count = uchan->tracefile_count;
342
343 /*
344 * Map enum lttng_ust_output to enum lttng_event_output.
345 */
346 switch (uchan->attr.output) {
347 case LTTNG_UST_MMAP:
348 channels[i].attr.output = LTTNG_EVENT_MMAP;
349 break;
350 default:
351 /*
352 * LTTNG_UST_MMAP is the only supported UST
353 * output mode.
354 */
355 assert(0);
356 break;
357 }
358
359 chan_exts[i].monitor_timer_interval =
360 uchan->monitor_timer_interval;
361 chan_exts[i].blocking_timeout =
362 uchan->attr.u.s.blocking_timeout;
363
364 ret = get_ust_runtime_stats(session, uchan,
365 &discarded_events, &lost_packets);
366 if (ret < 0) {
367 break;
368 }
369 chan_exts[i].discarded_events = discarded_events;
370 chan_exts[i].lost_packets = lost_packets;
371 i++;
372 }
373 rcu_read_unlock();
374 break;
375 }
376 default:
377 break;
378 }
379
380 end:
381 if (ret < 0) {
382 return -LTTNG_ERR_FATAL;
383 } else {
384 return LTTNG_OK;
385 }
386 }
387
388 static int increment_extended_len(const char *filter_expression,
389 struct lttng_event_exclusion *exclusion,
390 const struct lttng_userspace_probe_location *probe_location,
391 size_t *extended_len)
392 {
393 int ret = 0;
394
395 *extended_len += sizeof(struct lttcomm_event_extended_header);
396
397 if (filter_expression) {
398 *extended_len += strlen(filter_expression) + 1;
399 }
400
401 if (exclusion) {
402 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
403 }
404
405 if (probe_location) {
406 ret = lttng_userspace_probe_location_serialize(probe_location,
407 NULL, NULL);
408 if (ret < 0) {
409 goto end;
410 }
411 *extended_len += ret;
412 }
413 ret = 0;
414 end:
415 return ret;
416 }
417
418 static int append_extended_info(const char *filter_expression,
419 struct lttng_event_exclusion *exclusion,
420 struct lttng_userspace_probe_location *probe_location,
421 void **extended_at)
422 {
423 int ret = 0;
424 size_t filter_len = 0;
425 size_t nb_exclusions = 0;
426 size_t userspace_probe_location_len = 0;
427 struct lttng_dynamic_buffer location_buffer;
428 struct lttcomm_event_extended_header extended_header;
429
430 if (filter_expression) {
431 filter_len = strlen(filter_expression) + 1;
432 }
433
434 if (exclusion) {
435 nb_exclusions = exclusion->count;
436 }
437
438 if (probe_location) {
439 lttng_dynamic_buffer_init(&location_buffer);
440 ret = lttng_userspace_probe_location_serialize(probe_location,
441 &location_buffer, NULL);
442 if (ret < 0) {
443 ret = -1;
444 goto end;
445 }
446 userspace_probe_location_len = location_buffer.size;
447 }
448
449 /* Set header fields */
450 extended_header.filter_len = filter_len;
451 extended_header.nb_exclusions = nb_exclusions;
452 extended_header.userspace_probe_location_len = userspace_probe_location_len;
453
454 /* Copy header */
455 memcpy(*extended_at, &extended_header, sizeof(extended_header));
456 *extended_at += sizeof(extended_header);
457
458 /* Copy filter string */
459 if (filter_expression) {
460 memcpy(*extended_at, filter_expression, filter_len);
461 *extended_at += filter_len;
462 }
463
464 /* Copy exclusion names */
465 if (exclusion) {
466 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
467
468 memcpy(*extended_at, &exclusion->names, len);
469 *extended_at += len;
470 }
471
472 if (probe_location) {
473 memcpy(*extended_at, location_buffer.data, location_buffer.size);
474 *extended_at += location_buffer.size;
475 lttng_dynamic_buffer_reset(&location_buffer);
476 }
477 ret = 0;
478 end:
479 return ret;
480 }
481
482 /*
483 * Create a list of agent domain events.
484 *
485 * Return number of events in list on success or else a negative value.
486 */
487 static int list_lttng_agent_events(struct agent *agt,
488 struct lttng_event **events, size_t *total_size)
489 {
490 int i = 0, ret = 0;
491 unsigned int nb_event = 0;
492 struct agent_event *event;
493 struct lttng_event *tmp_events = NULL;
494 struct lttng_ht_iter iter;
495 size_t extended_len = 0;
496 void *extended_at;
497
498 assert(agt);
499 assert(events);
500
501 DBG3("Listing agent events");
502
503 rcu_read_lock();
504 nb_event = lttng_ht_get_count(agt->events);
505 rcu_read_unlock();
506 if (nb_event == 0) {
507 ret = nb_event;
508 *total_size = 0;
509 goto error;
510 }
511
512 /* Compute required extended infos size */
513 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
514
515 /*
516 * This is only valid because the commands which add events are
517 * processed in the same thread as the listing.
518 */
519 rcu_read_lock();
520 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
521 ret = increment_extended_len(event->filter_expression, NULL, NULL,
522 &extended_len);
523 if (ret) {
524 DBG("Error computing the length of extended info message");
525 ret = -LTTNG_ERR_FATAL;
526 goto error;
527 }
528 }
529 rcu_read_unlock();
530
531 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
532 tmp_events = zmalloc(*total_size);
533 if (!tmp_events) {
534 PERROR("zmalloc agent events session");
535 ret = -LTTNG_ERR_FATAL;
536 goto error;
537 }
538
539 extended_at = ((uint8_t *) tmp_events) +
540 nb_event * sizeof(struct lttng_event);
541
542 rcu_read_lock();
543 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
544 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
545 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
546 tmp_events[i].enabled = event->enabled;
547 tmp_events[i].loglevel = event->loglevel_value;
548 tmp_events[i].loglevel_type = event->loglevel_type;
549 i++;
550
551 /* Append extended info */
552 ret = append_extended_info(event->filter_expression, NULL, NULL,
553 &extended_at);
554 if (ret) {
555 DBG("Error appending extended info message");
556 ret = -LTTNG_ERR_FATAL;
557 goto error;
558 }
559 }
560
561 *events = tmp_events;
562 ret = nb_event;
563 assert(nb_event == i);
564
565 end:
566 rcu_read_unlock();
567 return ret;
568 error:
569 free(tmp_events);
570 goto end;
571 }
572
573 /*
574 * Create a list of ust global domain events.
575 */
576 static int list_lttng_ust_global_events(char *channel_name,
577 struct ltt_ust_domain_global *ust_global,
578 struct lttng_event **events, size_t *total_size)
579 {
580 int i = 0, ret = 0;
581 unsigned int nb_event = 0;
582 struct lttng_ht_iter iter;
583 struct lttng_ht_node_str *node;
584 struct ltt_ust_channel *uchan;
585 struct ltt_ust_event *uevent;
586 struct lttng_event *tmp;
587 size_t extended_len = 0;
588 void *extended_at;
589
590 DBG("Listing UST global events for channel %s", channel_name);
591
592 rcu_read_lock();
593
594 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
595 node = lttng_ht_iter_get_node_str(&iter);
596 if (node == NULL) {
597 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
598 goto end;
599 }
600
601 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
602
603 nb_event = lttng_ht_get_count(uchan->events);
604 if (nb_event == 0) {
605 ret = nb_event;
606 *total_size = 0;
607 goto end;
608 }
609
610 DBG3("Listing UST global %d events", nb_event);
611
612 /* Compute required extended infos size */
613 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
614 if (uevent->internal) {
615 nb_event--;
616 continue;
617 }
618
619 ret = increment_extended_len(uevent->filter_expression,
620 uevent->exclusion, NULL, &extended_len);
621 if (ret) {
622 DBG("Error computing the length of extended info message");
623 ret = -LTTNG_ERR_FATAL;
624 goto end;
625 }
626 }
627 if (nb_event == 0) {
628 /* All events are internal, skip. */
629 ret = 0;
630 *total_size = 0;
631 goto end;
632 }
633
634 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
635 tmp = zmalloc(*total_size);
636 if (tmp == NULL) {
637 ret = -LTTNG_ERR_FATAL;
638 goto end;
639 }
640
641 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
642
643 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
644 if (uevent->internal) {
645 /* This event should remain hidden from clients */
646 continue;
647 }
648 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
649 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
650 tmp[i].enabled = uevent->enabled;
651
652 switch (uevent->attr.instrumentation) {
653 case LTTNG_UST_TRACEPOINT:
654 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
655 break;
656 case LTTNG_UST_PROBE:
657 tmp[i].type = LTTNG_EVENT_PROBE;
658 break;
659 case LTTNG_UST_FUNCTION:
660 tmp[i].type = LTTNG_EVENT_FUNCTION;
661 break;
662 }
663
664 tmp[i].loglevel = uevent->attr.loglevel;
665 switch (uevent->attr.loglevel_type) {
666 case LTTNG_UST_LOGLEVEL_ALL:
667 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
668 break;
669 case LTTNG_UST_LOGLEVEL_RANGE:
670 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
671 break;
672 case LTTNG_UST_LOGLEVEL_SINGLE:
673 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
674 break;
675 }
676 if (uevent->filter) {
677 tmp[i].filter = 1;
678 }
679 if (uevent->exclusion) {
680 tmp[i].exclusion = 1;
681 }
682 i++;
683
684 /* Append extended info */
685 ret = append_extended_info(uevent->filter_expression,
686 uevent->exclusion, NULL, &extended_at);
687 if (ret) {
688 DBG("Error appending extended info message");
689 ret = -LTTNG_ERR_FATAL;
690 goto end;
691 }
692 }
693
694 ret = nb_event;
695 *events = tmp;
696 end:
697 rcu_read_unlock();
698 return ret;
699 }
700
701 /*
702 * Fill lttng_event array of all kernel events in the channel.
703 */
704 static int list_lttng_kernel_events(char *channel_name,
705 struct ltt_kernel_session *kernel_session,
706 struct lttng_event **events, size_t *total_size)
707 {
708 int i = 0, ret;
709 unsigned int nb_event;
710 struct ltt_kernel_event *event;
711 struct ltt_kernel_channel *kchan;
712 size_t extended_len = 0;
713 void *extended_at;
714
715 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
716 if (kchan == NULL) {
717 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
718 goto error;
719 }
720
721 nb_event = kchan->event_count;
722
723 DBG("Listing events for channel %s", kchan->channel->name);
724
725 if (nb_event == 0) {
726 *total_size = 0;
727 *events = NULL;
728 goto end;
729 }
730
731 /* Compute required extended infos size */
732 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
733 ret = increment_extended_len(event->filter_expression, NULL,
734 event->userspace_probe_location,
735 &extended_len);
736 if (ret) {
737 DBG("Error computing the length of extended info message");
738 ret = -LTTNG_ERR_FATAL;
739 goto error;
740 }
741 }
742
743 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
744 *events = zmalloc(*total_size);
745 if (*events == NULL) {
746 ret = -LTTNG_ERR_FATAL;
747 goto error;
748 }
749
750 extended_at = ((void *) *events) +
751 nb_event * sizeof(struct lttng_event);
752
753 /* Kernel channels */
754 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
755 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
756 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
757 (*events)[i].enabled = event->enabled;
758 (*events)[i].filter =
759 (unsigned char) !!event->filter_expression;
760
761 switch (event->event->instrumentation) {
762 case LTTNG_KERNEL_TRACEPOINT:
763 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
764 break;
765 case LTTNG_KERNEL_KRETPROBE:
766 (*events)[i].type = LTTNG_EVENT_FUNCTION;
767 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
768 sizeof(struct lttng_kernel_kprobe));
769 break;
770 case LTTNG_KERNEL_KPROBE:
771 (*events)[i].type = LTTNG_EVENT_PROBE;
772 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
773 sizeof(struct lttng_kernel_kprobe));
774 break;
775 case LTTNG_KERNEL_UPROBE:
776 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
777 break;
778 case LTTNG_KERNEL_FUNCTION:
779 (*events)[i].type = LTTNG_EVENT_FUNCTION;
780 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
781 sizeof(struct lttng_kernel_function));
782 break;
783 case LTTNG_KERNEL_NOOP:
784 (*events)[i].type = LTTNG_EVENT_NOOP;
785 break;
786 case LTTNG_KERNEL_SYSCALL:
787 (*events)[i].type = LTTNG_EVENT_SYSCALL;
788 break;
789 case LTTNG_KERNEL_ALL:
790 /* fall-through. */
791 default:
792 assert(0);
793 break;
794 }
795 i++;
796
797 /* Append extended info */
798 ret = append_extended_info(event->filter_expression, NULL,
799 event->userspace_probe_location, &extended_at);
800 if (ret) {
801 DBG("Error appending extended info message");
802 ret = -LTTNG_ERR_FATAL;
803 goto error;
804 }
805 }
806
807 end:
808 return nb_event;
809
810 error:
811 /* Negate the error code to differentiate the size from an error */
812 return -ret;
813 }
814
815 /*
816 * Add URI so the consumer output object. Set the correct path depending on the
817 * domain adding the default trace directory.
818 */
819 static int add_uri_to_consumer(struct consumer_output *consumer,
820 struct lttng_uri *uri, enum lttng_domain_type domain,
821 const char *session_name)
822 {
823 int ret = LTTNG_OK;
824 const char *default_trace_dir;
825
826 assert(uri);
827
828 if (consumer == NULL) {
829 DBG("No consumer detected. Don't add URI. Stopping.");
830 ret = LTTNG_ERR_NO_CONSUMER;
831 goto error;
832 }
833
834 switch (domain) {
835 case LTTNG_DOMAIN_KERNEL:
836 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
837 break;
838 case LTTNG_DOMAIN_UST:
839 default_trace_dir = DEFAULT_UST_TRACE_DIR;
840 break;
841 default:
842 /*
843 * This case is possible is we try to add the URI to the global tracing
844 * session consumer object which in this case there is no subdir.
845 */
846 default_trace_dir = "";
847 }
848
849 switch (uri->dtype) {
850 case LTTNG_DST_IPV4:
851 case LTTNG_DST_IPV6:
852 DBG2("Setting network URI to consumer");
853
854 if (consumer->type == CONSUMER_DST_NET) {
855 if ((uri->stype == LTTNG_STREAM_CONTROL &&
856 consumer->dst.net.control_isset) ||
857 (uri->stype == LTTNG_STREAM_DATA &&
858 consumer->dst.net.data_isset)) {
859 ret = LTTNG_ERR_URL_EXIST;
860 goto error;
861 }
862 } else {
863 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
864 }
865
866 consumer->type = CONSUMER_DST_NET;
867
868 /* Set URI into consumer output object */
869 ret = consumer_set_network_uri(consumer, uri);
870 if (ret < 0) {
871 ret = -ret;
872 goto error;
873 } else if (ret == 1) {
874 /*
875 * URI was the same in the consumer so we do not append the subdir
876 * again so to not duplicate output dir.
877 */
878 ret = LTTNG_OK;
879 goto error;
880 }
881
882 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
883 ret = consumer_set_subdir(consumer, session_name);
884 if (ret < 0) {
885 ret = LTTNG_ERR_FATAL;
886 goto error;
887 }
888 }
889
890 if (uri->stype == LTTNG_STREAM_CONTROL) {
891 /* On a new subdir, reappend the default trace dir. */
892 strncat(consumer->subdir, default_trace_dir,
893 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
894 DBG3("Append domain trace name to subdir %s", consumer->subdir);
895 }
896
897 break;
898 case LTTNG_DST_PATH:
899 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
900 memset(consumer->dst.session_root_path, 0,
901 sizeof(consumer->dst.session_root_path));
902 /* Explicit length checks for strcpy and strcat. */
903 if (strlen(uri->dst.path) + strlen(default_trace_dir)
904 >= sizeof(consumer->dst.session_root_path)) {
905 ret = LTTNG_ERR_FATAL;
906 goto error;
907 }
908 strcpy(consumer->dst.session_root_path, uri->dst.path);
909 /* Append default trace dir */
910 strcat(consumer->dst.session_root_path, default_trace_dir);
911 /* Flag consumer as local. */
912 consumer->type = CONSUMER_DST_LOCAL;
913 break;
914 }
915
916 ret = LTTNG_OK;
917
918 error:
919 return ret;
920 }
921
922 /*
923 * Init tracing by creating trace directory and sending fds kernel consumer.
924 */
925 static int init_kernel_tracing(struct ltt_kernel_session *session)
926 {
927 int ret = 0;
928 struct lttng_ht_iter iter;
929 struct consumer_socket *socket;
930
931 assert(session);
932
933 rcu_read_lock();
934
935 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
936 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
937 socket, node.node) {
938 pthread_mutex_lock(socket->lock);
939 ret = kernel_consumer_send_session(socket, session);
940 pthread_mutex_unlock(socket->lock);
941 if (ret < 0) {
942 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
943 goto error;
944 }
945 }
946 }
947
948 error:
949 rcu_read_unlock();
950 return ret;
951 }
952
953 /*
954 * Create a socket to the relayd using the URI.
955 *
956 * On success, the relayd_sock pointer is set to the created socket.
957 * Else, it's stays untouched and a lttcomm error code is returned.
958 */
959 static int create_connect_relayd(struct lttng_uri *uri,
960 struct lttcomm_relayd_sock **relayd_sock,
961 struct consumer_output *consumer)
962 {
963 int ret;
964 struct lttcomm_relayd_sock *rsock;
965
966 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
967 RELAYD_VERSION_COMM_MINOR);
968 if (!rsock) {
969 ret = LTTNG_ERR_FATAL;
970 goto error;
971 }
972
973 /*
974 * Connect to relayd so we can proceed with a session creation. This call
975 * can possibly block for an arbitrary amount of time to set the health
976 * state to be in poll execution.
977 */
978 health_poll_entry();
979 ret = relayd_connect(rsock);
980 health_poll_exit();
981 if (ret < 0) {
982 ERR("Unable to reach lttng-relayd");
983 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
984 goto free_sock;
985 }
986
987 /* Create socket for control stream. */
988 if (uri->stype == LTTNG_STREAM_CONTROL) {
989 DBG3("Creating relayd stream socket from URI");
990
991 /* Check relayd version */
992 ret = relayd_version_check(rsock);
993 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
994 goto close_sock;
995 } else if (ret < 0) {
996 ERR("Unable to reach lttng-relayd");
997 ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
998 goto close_sock;
999 }
1000 consumer->relay_major_version = rsock->major;
1001 consumer->relay_minor_version = rsock->minor;
1002 } else if (uri->stype == LTTNG_STREAM_DATA) {
1003 DBG3("Creating relayd data socket from URI");
1004 } else {
1005 /* Command is not valid */
1006 ERR("Relayd invalid stream type: %d", uri->stype);
1007 ret = LTTNG_ERR_INVALID;
1008 goto close_sock;
1009 }
1010
1011 *relayd_sock = rsock;
1012
1013 return LTTNG_OK;
1014
1015 close_sock:
1016 /* The returned value is not useful since we are on an error path. */
1017 (void) relayd_close(rsock);
1018 free_sock:
1019 free(rsock);
1020 error:
1021 return ret;
1022 }
1023
1024 /*
1025 * Connect to the relayd using URI and send the socket to the right consumer.
1026 *
1027 * The consumer socket lock must be held by the caller.
1028 */
1029 static int send_consumer_relayd_socket(unsigned int session_id,
1030 struct lttng_uri *relayd_uri,
1031 struct consumer_output *consumer,
1032 struct consumer_socket *consumer_sock,
1033 char *session_name, char *hostname, int session_live_timer)
1034 {
1035 int ret;
1036 struct lttcomm_relayd_sock *rsock = NULL;
1037
1038 /* Connect to relayd and make version check if uri is the control. */
1039 ret = create_connect_relayd(relayd_uri, &rsock, consumer);
1040 if (ret != LTTNG_OK) {
1041 goto relayd_comm_error;
1042 }
1043 assert(rsock);
1044
1045 /* Set the network sequence index if not set. */
1046 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1047 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1048 /*
1049 * Increment net_seq_idx because we are about to transfer the
1050 * new relayd socket to the consumer.
1051 * Assign unique key so the consumer can match streams.
1052 */
1053 consumer->net_seq_index = ++relayd_net_seq_idx;
1054 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1055 }
1056
1057 /* Send relayd socket to consumer. */
1058 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1059 relayd_uri->stype, session_id,
1060 session_name, hostname, session_live_timer);
1061 if (ret < 0) {
1062 ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1063 goto close_sock;
1064 }
1065
1066 /* Flag that the corresponding socket was sent. */
1067 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1068 consumer_sock->control_sock_sent = 1;
1069 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1070 consumer_sock->data_sock_sent = 1;
1071 }
1072
1073 ret = LTTNG_OK;
1074
1075 /*
1076 * Close socket which was dup on the consumer side. The session daemon does
1077 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1078 */
1079
1080 close_sock:
1081 if (ret != LTTNG_OK) {
1082 /*
1083 * The consumer output for this session should not be used anymore
1084 * since the relayd connection failed thus making any tracing or/and
1085 * streaming not usable.
1086 */
1087 consumer->enabled = 0;
1088 }
1089 (void) relayd_close(rsock);
1090 free(rsock);
1091
1092 relayd_comm_error:
1093 return ret;
1094 }
1095
1096 /*
1097 * Send both relayd sockets to a specific consumer and domain. This is a
1098 * helper function to facilitate sending the information to the consumer for a
1099 * session.
1100 *
1101 * The consumer socket lock must be held by the caller.
1102 */
1103 static int send_consumer_relayd_sockets(enum lttng_domain_type domain,
1104 unsigned int session_id, struct consumer_output *consumer,
1105 struct consumer_socket *sock, char *session_name,
1106 char *hostname, int session_live_timer)
1107 {
1108 int ret = LTTNG_OK;
1109
1110 assert(consumer);
1111 assert(sock);
1112
1113 /* Sending control relayd socket. */
1114 if (!sock->control_sock_sent) {
1115 ret = send_consumer_relayd_socket(session_id,
1116 &consumer->dst.net.control, consumer, sock,
1117 session_name, hostname, session_live_timer);
1118 if (ret != LTTNG_OK) {
1119 goto error;
1120 }
1121 }
1122
1123 /* Sending data relayd socket. */
1124 if (!sock->data_sock_sent) {
1125 ret = send_consumer_relayd_socket(session_id,
1126 &consumer->dst.net.data, consumer, sock,
1127 session_name, hostname, session_live_timer);
1128 if (ret != LTTNG_OK) {
1129 goto error;
1130 }
1131 }
1132
1133 error:
1134 return ret;
1135 }
1136
1137 /*
1138 * Setup relayd connections for a tracing session. First creates the socket to
1139 * the relayd and send them to the right domain consumer. Consumer type MUST be
1140 * network.
1141 */
1142 int cmd_setup_relayd(struct ltt_session *session)
1143 {
1144 int ret = LTTNG_OK;
1145 struct ltt_ust_session *usess;
1146 struct ltt_kernel_session *ksess;
1147 struct consumer_socket *socket;
1148 struct lttng_ht_iter iter;
1149
1150 assert(session);
1151
1152 usess = session->ust_session;
1153 ksess = session->kernel_session;
1154
1155 DBG("Setting relayd for session %s", session->name);
1156
1157 rcu_read_lock();
1158
1159 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1160 && usess->consumer->enabled) {
1161 /* For each consumer socket, send relayd sockets */
1162 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1163 socket, node.node) {
1164 pthread_mutex_lock(socket->lock);
1165 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1166 usess->consumer, socket,
1167 session->name, session->hostname,
1168 session->live_timer);
1169 pthread_mutex_unlock(socket->lock);
1170 if (ret != LTTNG_OK) {
1171 goto error;
1172 }
1173 /* Session is now ready for network streaming. */
1174 session->net_handle = 1;
1175 }
1176 session->consumer->relay_major_version =
1177 usess->consumer->relay_major_version;
1178 session->consumer->relay_minor_version =
1179 usess->consumer->relay_minor_version;
1180 }
1181
1182 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1183 && ksess->consumer->enabled) {
1184 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1185 socket, node.node) {
1186 pthread_mutex_lock(socket->lock);
1187 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1188 ksess->consumer, socket,
1189 session->name, session->hostname,
1190 session->live_timer);
1191 pthread_mutex_unlock(socket->lock);
1192 if (ret != LTTNG_OK) {
1193 goto error;
1194 }
1195 /* Session is now ready for network streaming. */
1196 session->net_handle = 1;
1197 }
1198 session->consumer->relay_major_version =
1199 ksess->consumer->relay_major_version;
1200 session->consumer->relay_minor_version =
1201 ksess->consumer->relay_minor_version;
1202 }
1203
1204 error:
1205 rcu_read_unlock();
1206 return ret;
1207 }
1208
1209 /*
1210 * Start a kernel session by opening all necessary streams.
1211 */
1212 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1213 {
1214 int ret;
1215 struct ltt_kernel_channel *kchan;
1216
1217 /* Open kernel metadata */
1218 if (ksess->metadata == NULL && ksess->output_traces) {
1219 ret = kernel_open_metadata(ksess);
1220 if (ret < 0) {
1221 ret = LTTNG_ERR_KERN_META_FAIL;
1222 goto error;
1223 }
1224 }
1225
1226 /* Open kernel metadata stream */
1227 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1228 ret = kernel_open_metadata_stream(ksess);
1229 if (ret < 0) {
1230 ERR("Kernel create metadata stream failed");
1231 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1232 goto error;
1233 }
1234 }
1235
1236 /* For each channel */
1237 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1238 if (kchan->stream_count == 0) {
1239 ret = kernel_open_channel_stream(kchan);
1240 if (ret < 0) {
1241 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1242 goto error;
1243 }
1244 /* Update the stream global counter */
1245 ksess->stream_count_global += ret;
1246 }
1247 }
1248
1249 /* Setup kernel consumer socket and send fds to it */
1250 ret = init_kernel_tracing(ksess);
1251 if (ret != 0) {
1252 ret = LTTNG_ERR_KERN_START_FAIL;
1253 goto error;
1254 }
1255
1256 /* This start the kernel tracing */
1257 ret = kernel_start_session(ksess);
1258 if (ret < 0) {
1259 ret = LTTNG_ERR_KERN_START_FAIL;
1260 goto error;
1261 }
1262
1263 /* Quiescent wait after starting trace */
1264 kernel_wait_quiescent(wpipe);
1265
1266 ksess->active = 1;
1267
1268 ret = LTTNG_OK;
1269
1270 error:
1271 return ret;
1272 }
1273
1274 /*
1275 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1276 */
1277 int cmd_disable_channel(struct ltt_session *session,
1278 enum lttng_domain_type domain, char *channel_name)
1279 {
1280 int ret;
1281 struct ltt_ust_session *usess;
1282
1283 usess = session->ust_session;
1284
1285 rcu_read_lock();
1286
1287 switch (domain) {
1288 case LTTNG_DOMAIN_KERNEL:
1289 {
1290 ret = channel_kernel_disable(session->kernel_session,
1291 channel_name);
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_channel *uchan;
1302 struct lttng_ht *chan_ht;
1303
1304 chan_ht = usess->domain_global.channels;
1305
1306 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1307 if (uchan == NULL) {
1308 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1309 goto error;
1310 }
1311
1312 ret = channel_ust_disable(usess, uchan);
1313 if (ret != LTTNG_OK) {
1314 goto error;
1315 }
1316 break;
1317 }
1318 default:
1319 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1320 goto error;
1321 }
1322
1323 ret = LTTNG_OK;
1324
1325 error:
1326 rcu_read_unlock();
1327 return ret;
1328 }
1329
1330 /*
1331 * Command LTTNG_TRACK_PID processed by the client thread.
1332 *
1333 * Called with session lock held.
1334 */
1335 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1336 int pid)
1337 {
1338 int ret;
1339
1340 rcu_read_lock();
1341
1342 switch (domain) {
1343 case LTTNG_DOMAIN_KERNEL:
1344 {
1345 struct ltt_kernel_session *ksess;
1346
1347 ksess = session->kernel_session;
1348
1349 ret = kernel_track_pid(ksess, pid);
1350 if (ret != LTTNG_OK) {
1351 goto error;
1352 }
1353
1354 kernel_wait_quiescent(kernel_tracer_fd);
1355 break;
1356 }
1357 case LTTNG_DOMAIN_UST:
1358 {
1359 struct ltt_ust_session *usess;
1360
1361 usess = session->ust_session;
1362
1363 ret = trace_ust_track_pid(usess, pid);
1364 if (ret != LTTNG_OK) {
1365 goto error;
1366 }
1367 break;
1368 }
1369 default:
1370 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1371 goto error;
1372 }
1373
1374 ret = LTTNG_OK;
1375
1376 error:
1377 rcu_read_unlock();
1378 return ret;
1379 }
1380
1381 /*
1382 * Command LTTNG_UNTRACK_PID processed by the client thread.
1383 *
1384 * Called with session lock held.
1385 */
1386 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1387 int pid)
1388 {
1389 int ret;
1390
1391 rcu_read_lock();
1392
1393 switch (domain) {
1394 case LTTNG_DOMAIN_KERNEL:
1395 {
1396 struct ltt_kernel_session *ksess;
1397
1398 ksess = session->kernel_session;
1399
1400 ret = kernel_untrack_pid(ksess, pid);
1401 if (ret != LTTNG_OK) {
1402 goto error;
1403 }
1404
1405 kernel_wait_quiescent(kernel_tracer_fd);
1406 break;
1407 }
1408 case LTTNG_DOMAIN_UST:
1409 {
1410 struct ltt_ust_session *usess;
1411
1412 usess = session->ust_session;
1413
1414 ret = trace_ust_untrack_pid(usess, pid);
1415 if (ret != LTTNG_OK) {
1416 goto error;
1417 }
1418 break;
1419 }
1420 default:
1421 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1422 goto error;
1423 }
1424
1425 ret = LTTNG_OK;
1426
1427 error:
1428 rcu_read_unlock();
1429 return ret;
1430 }
1431
1432 /*
1433 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1434 *
1435 * The wpipe arguments is used as a notifier for the kernel thread.
1436 */
1437 int cmd_enable_channel(struct ltt_session *session,
1438 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1439 {
1440 int ret;
1441 struct ltt_ust_session *usess = session->ust_session;
1442 struct lttng_ht *chan_ht;
1443 size_t len;
1444
1445 assert(session);
1446 assert(attr);
1447 assert(domain);
1448
1449 len = lttng_strnlen(attr->name, sizeof(attr->name));
1450
1451 /* Validate channel name */
1452 if (attr->name[0] == '.' ||
1453 memchr(attr->name, '/', len) != NULL) {
1454 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1455 goto end;
1456 }
1457
1458 DBG("Enabling channel %s for session %s", attr->name, session->name);
1459
1460 rcu_read_lock();
1461
1462 /*
1463 * Don't try to enable a channel if the session has been started at
1464 * some point in time before. The tracer does not allow it.
1465 */
1466 if (session->has_been_started) {
1467 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1468 goto error;
1469 }
1470
1471 /*
1472 * If the session is a live session, remove the switch timer, the
1473 * live timer does the same thing but sends also synchronisation
1474 * beacons for inactive streams.
1475 */
1476 if (session->live_timer > 0) {
1477 attr->attr.live_timer_interval = session->live_timer;
1478 attr->attr.switch_timer_interval = 0;
1479 }
1480
1481 /* Check for feature support */
1482 switch (domain->type) {
1483 case LTTNG_DOMAIN_KERNEL:
1484 {
1485 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1486 /* Sampling position of buffer is not supported */
1487 WARN("Kernel tracer does not support buffer monitoring. "
1488 "Setting the monitor interval timer to 0 "
1489 "(disabled) for channel '%s' of session '%s'",
1490 attr-> name, session->name);
1491 lttng_channel_set_monitor_timer_interval(attr, 0);
1492 }
1493 break;
1494 }
1495 case LTTNG_DOMAIN_UST:
1496 break;
1497 case LTTNG_DOMAIN_JUL:
1498 case LTTNG_DOMAIN_LOG4J:
1499 case LTTNG_DOMAIN_PYTHON:
1500 if (!agent_tracing_is_enabled()) {
1501 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1502 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1503 goto error;
1504 }
1505 break;
1506 default:
1507 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1508 goto error;
1509 }
1510
1511 switch (domain->type) {
1512 case LTTNG_DOMAIN_KERNEL:
1513 {
1514 struct ltt_kernel_channel *kchan;
1515
1516 kchan = trace_kernel_get_channel_by_name(attr->name,
1517 session->kernel_session);
1518 if (kchan == NULL) {
1519 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1520 if (attr->name[0] != '\0') {
1521 session->kernel_session->has_non_default_channel = 1;
1522 }
1523 } else {
1524 ret = channel_kernel_enable(session->kernel_session, kchan);
1525 }
1526
1527 if (ret != LTTNG_OK) {
1528 goto error;
1529 }
1530
1531 kernel_wait_quiescent(kernel_tracer_fd);
1532 break;
1533 }
1534 case LTTNG_DOMAIN_UST:
1535 case LTTNG_DOMAIN_JUL:
1536 case LTTNG_DOMAIN_LOG4J:
1537 case LTTNG_DOMAIN_PYTHON:
1538 {
1539 struct ltt_ust_channel *uchan;
1540
1541 /*
1542 * FIXME
1543 *
1544 * Current agent implementation limitations force us to allow
1545 * only one channel at once in "agent" subdomains. Each
1546 * subdomain has a default channel name which must be strictly
1547 * adhered to.
1548 */
1549 if (domain->type == LTTNG_DOMAIN_JUL) {
1550 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1551 LTTNG_SYMBOL_NAME_LEN)) {
1552 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1553 goto error;
1554 }
1555 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1556 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1557 LTTNG_SYMBOL_NAME_LEN)) {
1558 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1559 goto error;
1560 }
1561 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1562 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1563 LTTNG_SYMBOL_NAME_LEN)) {
1564 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1565 goto error;
1566 }
1567 }
1568
1569 chan_ht = usess->domain_global.channels;
1570
1571 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1572 if (uchan == NULL) {
1573 ret = channel_ust_create(usess, attr, domain->buf_type);
1574 if (attr->name[0] != '\0') {
1575 usess->has_non_default_channel = 1;
1576 }
1577 } else {
1578 ret = channel_ust_enable(usess, uchan);
1579 }
1580 break;
1581 }
1582 default:
1583 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1584 goto error;
1585 }
1586
1587 error:
1588 rcu_read_unlock();
1589 end:
1590 return ret;
1591 }
1592
1593 /*
1594 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1595 */
1596 int cmd_disable_event(struct ltt_session *session,
1597 enum lttng_domain_type domain, char *channel_name,
1598 struct lttng_event *event)
1599 {
1600 int ret;
1601 char *event_name;
1602
1603 DBG("Disable event command for event \'%s\'", event->name);
1604
1605 event_name = event->name;
1606
1607 /* Error out on unhandled search criteria */
1608 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1609 || event->pid || event->filter || event->exclusion) {
1610 ret = LTTNG_ERR_UNK;
1611 goto error;
1612 }
1613
1614 rcu_read_lock();
1615
1616 switch (domain) {
1617 case LTTNG_DOMAIN_KERNEL:
1618 {
1619 struct ltt_kernel_channel *kchan;
1620 struct ltt_kernel_session *ksess;
1621
1622 ksess = session->kernel_session;
1623
1624 /*
1625 * If a non-default channel has been created in the
1626 * session, explicitely require that -c chan_name needs
1627 * to be provided.
1628 */
1629 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1630 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1631 goto error_unlock;
1632 }
1633
1634 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1635 if (kchan == NULL) {
1636 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1637 goto error_unlock;
1638 }
1639
1640 switch (event->type) {
1641 case LTTNG_EVENT_ALL:
1642 case LTTNG_EVENT_TRACEPOINT:
1643 case LTTNG_EVENT_SYSCALL:
1644 case LTTNG_EVENT_PROBE:
1645 case LTTNG_EVENT_FUNCTION:
1646 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1647 if (event_name[0] == '\0') {
1648 ret = event_kernel_disable_event(kchan,
1649 NULL, event->type);
1650 } else {
1651 ret = event_kernel_disable_event(kchan,
1652 event_name, event->type);
1653 }
1654 if (ret != LTTNG_OK) {
1655 goto error_unlock;
1656 }
1657 break;
1658 default:
1659 ret = LTTNG_ERR_UNK;
1660 goto error_unlock;
1661 }
1662
1663 kernel_wait_quiescent(kernel_tracer_fd);
1664 break;
1665 }
1666 case LTTNG_DOMAIN_UST:
1667 {
1668 struct ltt_ust_channel *uchan;
1669 struct ltt_ust_session *usess;
1670
1671 usess = session->ust_session;
1672
1673 if (validate_ust_event_name(event_name)) {
1674 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1675 goto error_unlock;
1676 }
1677
1678 /*
1679 * If a non-default channel has been created in the
1680 * session, explicitly require that -c chan_name needs
1681 * to be provided.
1682 */
1683 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1684 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1685 goto error_unlock;
1686 }
1687
1688 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1689 channel_name);
1690 if (uchan == NULL) {
1691 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1692 goto error_unlock;
1693 }
1694
1695 switch (event->type) {
1696 case LTTNG_EVENT_ALL:
1697 /*
1698 * An empty event name means that everything
1699 * should be disabled.
1700 */
1701 if (event->name[0] == '\0') {
1702 ret = event_ust_disable_all_tracepoints(usess, uchan);
1703 } else {
1704 ret = event_ust_disable_tracepoint(usess, uchan,
1705 event_name);
1706 }
1707 if (ret != LTTNG_OK) {
1708 goto error_unlock;
1709 }
1710 break;
1711 default:
1712 ret = LTTNG_ERR_UNK;
1713 goto error_unlock;
1714 }
1715
1716 DBG3("Disable UST event %s in channel %s completed", event_name,
1717 channel_name);
1718 break;
1719 }
1720 case LTTNG_DOMAIN_LOG4J:
1721 case LTTNG_DOMAIN_JUL:
1722 case LTTNG_DOMAIN_PYTHON:
1723 {
1724 struct agent *agt;
1725 struct ltt_ust_session *usess = session->ust_session;
1726
1727 assert(usess);
1728
1729 switch (event->type) {
1730 case LTTNG_EVENT_ALL:
1731 break;
1732 default:
1733 ret = LTTNG_ERR_UNK;
1734 goto error_unlock;
1735 }
1736
1737 agt = trace_ust_find_agent(usess, domain);
1738 if (!agt) {
1739 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1740 goto error_unlock;
1741 }
1742 /*
1743 * An empty event name means that everything
1744 * should be disabled.
1745 */
1746 if (event->name[0] == '\0') {
1747 ret = event_agent_disable_all(usess, agt);
1748 } else {
1749 ret = event_agent_disable(usess, agt, event_name);
1750 }
1751 if (ret != LTTNG_OK) {
1752 goto error_unlock;
1753 }
1754
1755 break;
1756 }
1757 default:
1758 ret = LTTNG_ERR_UND;
1759 goto error_unlock;
1760 }
1761
1762 ret = LTTNG_OK;
1763
1764 error_unlock:
1765 rcu_read_unlock();
1766 error:
1767 return ret;
1768 }
1769
1770 /*
1771 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1772 */
1773 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1774 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1775 {
1776 int ret, chan_kern_created = 0, chan_ust_created = 0;
1777 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1778
1779 /*
1780 * Don't try to add a context if the session has been started at
1781 * some point in time before. The tracer does not allow it and would
1782 * result in a corrupted trace.
1783 */
1784 if (session->has_been_started) {
1785 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1786 goto end;
1787 }
1788
1789 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1790 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1791 app_ctx_name = ctx->u.app_ctx.ctx_name;
1792 }
1793
1794 switch (domain) {
1795 case LTTNG_DOMAIN_KERNEL:
1796 assert(session->kernel_session);
1797
1798 if (session->kernel_session->channel_count == 0) {
1799 /* Create default channel */
1800 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1801 if (ret != LTTNG_OK) {
1802 goto error;
1803 }
1804 chan_kern_created = 1;
1805 }
1806 /* Add kernel context to kernel tracer */
1807 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1808 if (ret != LTTNG_OK) {
1809 goto error;
1810 }
1811 break;
1812 case LTTNG_DOMAIN_JUL:
1813 case LTTNG_DOMAIN_LOG4J:
1814 {
1815 /*
1816 * Validate channel name.
1817 * If no channel name is given and the domain is JUL or LOG4J,
1818 * set it to the appropriate domain-specific channel name. If
1819 * a name is provided but does not match the expexted channel
1820 * name, return an error.
1821 */
1822 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1823 strcmp(channel_name,
1824 DEFAULT_JUL_CHANNEL_NAME)) {
1825 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1826 goto error;
1827 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1828 strcmp(channel_name,
1829 DEFAULT_LOG4J_CHANNEL_NAME)) {
1830 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1831 goto error;
1832 }
1833 /* break is _not_ missing here. */
1834 }
1835 case LTTNG_DOMAIN_UST:
1836 {
1837 struct ltt_ust_session *usess = session->ust_session;
1838 unsigned int chan_count;
1839
1840 assert(usess);
1841
1842 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1843 if (chan_count == 0) {
1844 struct lttng_channel *attr;
1845 /* Create default channel */
1846 attr = channel_new_default_attr(domain, usess->buffer_type);
1847 if (attr == NULL) {
1848 ret = LTTNG_ERR_FATAL;
1849 goto error;
1850 }
1851
1852 ret = channel_ust_create(usess, attr, usess->buffer_type);
1853 if (ret != LTTNG_OK) {
1854 free(attr);
1855 goto error;
1856 }
1857 channel_attr_destroy(attr);
1858 chan_ust_created = 1;
1859 }
1860
1861 ret = context_ust_add(usess, domain, ctx, channel_name);
1862 free(app_ctx_provider_name);
1863 free(app_ctx_name);
1864 app_ctx_name = NULL;
1865 app_ctx_provider_name = NULL;
1866 if (ret != LTTNG_OK) {
1867 goto error;
1868 }
1869 break;
1870 }
1871 default:
1872 ret = LTTNG_ERR_UND;
1873 goto error;
1874 }
1875
1876 ret = LTTNG_OK;
1877 goto end;
1878
1879 error:
1880 if (chan_kern_created) {
1881 struct ltt_kernel_channel *kchan =
1882 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1883 session->kernel_session);
1884 /* Created previously, this should NOT fail. */
1885 assert(kchan);
1886 kernel_destroy_channel(kchan);
1887 }
1888
1889 if (chan_ust_created) {
1890 struct ltt_ust_channel *uchan =
1891 trace_ust_find_channel_by_name(
1892 session->ust_session->domain_global.channels,
1893 DEFAULT_CHANNEL_NAME);
1894 /* Created previously, this should NOT fail. */
1895 assert(uchan);
1896 /* Remove from the channel list of the session. */
1897 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1898 uchan);
1899 trace_ust_destroy_channel(uchan);
1900 }
1901 end:
1902 free(app_ctx_provider_name);
1903 free(app_ctx_name);
1904 return ret;
1905 }
1906
1907 static inline bool name_starts_with(const char *name, const char *prefix)
1908 {
1909 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1910
1911 return !strncmp(name, prefix, max_cmp_len);
1912 }
1913
1914 /* Perform userspace-specific event name validation */
1915 static int validate_ust_event_name(const char *name)
1916 {
1917 int ret = 0;
1918
1919 if (!name) {
1920 ret = -1;
1921 goto end;
1922 }
1923
1924 /*
1925 * Check name against all internal UST event component namespaces used
1926 * by the agents.
1927 */
1928 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1929 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1930 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1931 ret = -1;
1932 }
1933
1934 end:
1935 return ret;
1936 }
1937
1938 /*
1939 * Internal version of cmd_enable_event() with a supplemental
1940 * "internal_event" flag which is used to enable internal events which should
1941 * be hidden from clients. Such events are used in the agent implementation to
1942 * enable the events through which all "agent" events are funeled.
1943 */
1944 static int _cmd_enable_event(struct ltt_session *session,
1945 struct lttng_domain *domain,
1946 char *channel_name, struct lttng_event *event,
1947 char *filter_expression,
1948 struct lttng_filter_bytecode *filter,
1949 struct lttng_event_exclusion *exclusion,
1950 int wpipe, bool internal_event)
1951 {
1952 int ret = 0, channel_created = 0;
1953 struct lttng_channel *attr = NULL;
1954
1955 assert(session);
1956 assert(event);
1957 assert(channel_name);
1958
1959 /* If we have a filter, we must have its filter expression */
1960 assert(!(!!filter_expression ^ !!filter));
1961
1962 /* Normalize event name as a globbing pattern */
1963 strutils_normalize_star_glob_pattern(event->name);
1964
1965 /* Normalize exclusion names as globbing patterns */
1966 if (exclusion) {
1967 size_t i;
1968
1969 for (i = 0; i < exclusion->count; i++) {
1970 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
1971
1972 strutils_normalize_star_glob_pattern(name);
1973 }
1974 }
1975
1976 DBG("Enable event command for event \'%s\'", event->name);
1977
1978 rcu_read_lock();
1979
1980 switch (domain->type) {
1981 case LTTNG_DOMAIN_KERNEL:
1982 {
1983 struct ltt_kernel_channel *kchan;
1984
1985 /*
1986 * If a non-default channel has been created in the
1987 * session, explicitely require that -c chan_name needs
1988 * to be provided.
1989 */
1990 if (session->kernel_session->has_non_default_channel
1991 && channel_name[0] == '\0') {
1992 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1993 goto error;
1994 }
1995
1996 kchan = trace_kernel_get_channel_by_name(channel_name,
1997 session->kernel_session);
1998 if (kchan == NULL) {
1999 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2000 LTTNG_BUFFER_GLOBAL);
2001 if (attr == NULL) {
2002 ret = LTTNG_ERR_FATAL;
2003 goto error;
2004 }
2005 if (lttng_strncpy(attr->name, channel_name,
2006 sizeof(attr->name))) {
2007 ret = LTTNG_ERR_INVALID;
2008 goto error;
2009 }
2010
2011 ret = cmd_enable_channel(session, domain, attr, wpipe);
2012 if (ret != LTTNG_OK) {
2013 goto error;
2014 }
2015 channel_created = 1;
2016 }
2017
2018 /* Get the newly created kernel channel pointer */
2019 kchan = trace_kernel_get_channel_by_name(channel_name,
2020 session->kernel_session);
2021 if (kchan == NULL) {
2022 /* This sould not happen... */
2023 ret = LTTNG_ERR_FATAL;
2024 goto error;
2025 }
2026
2027 switch (event->type) {
2028 case LTTNG_EVENT_ALL:
2029 {
2030 char *filter_expression_a = NULL;
2031 struct lttng_filter_bytecode *filter_a = NULL;
2032
2033 /*
2034 * We need to duplicate filter_expression and filter,
2035 * because ownership is passed to first enable
2036 * event.
2037 */
2038 if (filter_expression) {
2039 filter_expression_a = strdup(filter_expression);
2040 if (!filter_expression_a) {
2041 ret = LTTNG_ERR_FATAL;
2042 goto error;
2043 }
2044 }
2045 if (filter) {
2046 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2047 if (!filter_a) {
2048 free(filter_expression_a);
2049 ret = LTTNG_ERR_FATAL;
2050 goto error;
2051 }
2052 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2053 }
2054 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2055 ret = event_kernel_enable_event(kchan, event,
2056 filter_expression, filter);
2057 /* We have passed ownership */
2058 filter_expression = NULL;
2059 filter = NULL;
2060 if (ret != LTTNG_OK) {
2061 if (channel_created) {
2062 /* Let's not leak a useless channel. */
2063 kernel_destroy_channel(kchan);
2064 }
2065 free(filter_expression_a);
2066 free(filter_a);
2067 goto error;
2068 }
2069 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2070 ret = event_kernel_enable_event(kchan, event,
2071 filter_expression_a, filter_a);
2072 /* We have passed ownership */
2073 filter_expression_a = NULL;
2074 filter_a = NULL;
2075 if (ret != LTTNG_OK) {
2076 goto error;
2077 }
2078 break;
2079 }
2080 case LTTNG_EVENT_PROBE:
2081 case LTTNG_EVENT_USERSPACE_PROBE:
2082 case LTTNG_EVENT_FUNCTION:
2083 case LTTNG_EVENT_FUNCTION_ENTRY:
2084 case LTTNG_EVENT_TRACEPOINT:
2085 ret = event_kernel_enable_event(kchan, event,
2086 filter_expression, filter);
2087 /* We have passed ownership */
2088 filter_expression = NULL;
2089 filter = NULL;
2090 if (ret != LTTNG_OK) {
2091 if (channel_created) {
2092 /* Let's not leak a useless channel. */
2093 kernel_destroy_channel(kchan);
2094 }
2095 goto error;
2096 }
2097 break;
2098 case LTTNG_EVENT_SYSCALL:
2099 ret = event_kernel_enable_event(kchan, event,
2100 filter_expression, filter);
2101 /* We have passed ownership */
2102 filter_expression = NULL;
2103 filter = NULL;
2104 if (ret != LTTNG_OK) {
2105 goto error;
2106 }
2107 break;
2108 default:
2109 ret = LTTNG_ERR_UNK;
2110 goto error;
2111 }
2112
2113 kernel_wait_quiescent(kernel_tracer_fd);
2114 break;
2115 }
2116 case LTTNG_DOMAIN_UST:
2117 {
2118 struct ltt_ust_channel *uchan;
2119 struct ltt_ust_session *usess = session->ust_session;
2120
2121 assert(usess);
2122
2123 /*
2124 * If a non-default channel has been created in the
2125 * session, explicitely require that -c chan_name needs
2126 * to be provided.
2127 */
2128 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2129 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2130 goto error;
2131 }
2132
2133 /* Get channel from global UST domain */
2134 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2135 channel_name);
2136 if (uchan == NULL) {
2137 /* Create default channel */
2138 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2139 usess->buffer_type);
2140 if (attr == NULL) {
2141 ret = LTTNG_ERR_FATAL;
2142 goto error;
2143 }
2144 if (lttng_strncpy(attr->name, channel_name,
2145 sizeof(attr->name))) {
2146 ret = LTTNG_ERR_INVALID;
2147 goto error;
2148 }
2149
2150 ret = cmd_enable_channel(session, domain, attr, wpipe);
2151 if (ret != LTTNG_OK) {
2152 goto error;
2153 }
2154
2155 /* Get the newly created channel reference back */
2156 uchan = trace_ust_find_channel_by_name(
2157 usess->domain_global.channels, channel_name);
2158 assert(uchan);
2159 }
2160
2161 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2162 /*
2163 * Don't allow users to add UST events to channels which
2164 * are assigned to a userspace subdomain (JUL, Log4J,
2165 * Python, etc.).
2166 */
2167 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2168 goto error;
2169 }
2170
2171 if (!internal_event) {
2172 /*
2173 * Ensure the event name is not reserved for internal
2174 * use.
2175 */
2176 ret = validate_ust_event_name(event->name);
2177 if (ret) {
2178 WARN("Userspace event name %s failed validation.",
2179 event->name);
2180 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2181 goto error;
2182 }
2183 }
2184
2185 /* At this point, the session and channel exist on the tracer */
2186 ret = event_ust_enable_tracepoint(usess, uchan, event,
2187 filter_expression, filter, exclusion,
2188 internal_event);
2189 /* We have passed ownership */
2190 filter_expression = NULL;
2191 filter = NULL;
2192 exclusion = NULL;
2193 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2194 goto already_enabled;
2195 } else if (ret != LTTNG_OK) {
2196 goto error;
2197 }
2198 break;
2199 }
2200 case LTTNG_DOMAIN_LOG4J:
2201 case LTTNG_DOMAIN_JUL:
2202 case LTTNG_DOMAIN_PYTHON:
2203 {
2204 const char *default_event_name, *default_chan_name;
2205 struct agent *agt;
2206 struct lttng_event uevent;
2207 struct lttng_domain tmp_dom;
2208 struct ltt_ust_session *usess = session->ust_session;
2209
2210 assert(usess);
2211
2212 if (!agent_tracing_is_enabled()) {
2213 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2214 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2215 goto error;
2216 }
2217
2218 agt = trace_ust_find_agent(usess, domain->type);
2219 if (!agt) {
2220 agt = agent_create(domain->type);
2221 if (!agt) {
2222 ret = LTTNG_ERR_NOMEM;
2223 goto error;
2224 }
2225 agent_add(agt, usess->agents);
2226 }
2227
2228 /* Create the default tracepoint. */
2229 memset(&uevent, 0, sizeof(uevent));
2230 uevent.type = LTTNG_EVENT_TRACEPOINT;
2231 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2232 default_event_name = event_get_default_agent_ust_name(
2233 domain->type);
2234 if (!default_event_name) {
2235 ret = LTTNG_ERR_FATAL;
2236 goto error;
2237 }
2238 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2239 uevent.name[sizeof(uevent.name) - 1] = '\0';
2240
2241 /*
2242 * The domain type is changed because we are about to enable the
2243 * default channel and event for the JUL domain that are hardcoded.
2244 * This happens in the UST domain.
2245 */
2246 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2247 tmp_dom.type = LTTNG_DOMAIN_UST;
2248
2249 switch (domain->type) {
2250 case LTTNG_DOMAIN_LOG4J:
2251 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2252 break;
2253 case LTTNG_DOMAIN_JUL:
2254 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2255 break;
2256 case LTTNG_DOMAIN_PYTHON:
2257 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2258 break;
2259 default:
2260 /* The switch/case we are in makes this impossible */
2261 assert(0);
2262 }
2263
2264 {
2265 char *filter_expression_copy = NULL;
2266 struct lttng_filter_bytecode *filter_copy = NULL;
2267
2268 if (filter) {
2269 const size_t filter_size = sizeof(
2270 struct lttng_filter_bytecode)
2271 + filter->len;
2272
2273 filter_copy = zmalloc(filter_size);
2274 if (!filter_copy) {
2275 ret = LTTNG_ERR_NOMEM;
2276 goto error;
2277 }
2278 memcpy(filter_copy, filter, filter_size);
2279
2280 filter_expression_copy =
2281 strdup(filter_expression);
2282 if (!filter_expression) {
2283 ret = LTTNG_ERR_NOMEM;
2284 }
2285
2286 if (!filter_expression_copy || !filter_copy) {
2287 free(filter_expression_copy);
2288 free(filter_copy);
2289 goto error;
2290 }
2291 }
2292
2293 ret = cmd_enable_event_internal(session, &tmp_dom,
2294 (char *) default_chan_name,
2295 &uevent, filter_expression_copy,
2296 filter_copy, NULL, wpipe);
2297 }
2298
2299 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2300 goto already_enabled;
2301 } else if (ret != LTTNG_OK) {
2302 goto error;
2303 }
2304
2305 /* The wild card * means that everything should be enabled. */
2306 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2307 ret = event_agent_enable_all(usess, agt, event, filter,
2308 filter_expression);
2309 } else {
2310 ret = event_agent_enable(usess, agt, event, filter,
2311 filter_expression);
2312 }
2313 filter = NULL;
2314 filter_expression = NULL;
2315 if (ret != LTTNG_OK) {
2316 goto error;
2317 }
2318
2319 break;
2320 }
2321 default:
2322 ret = LTTNG_ERR_UND;
2323 goto error;
2324 }
2325
2326 ret = LTTNG_OK;
2327
2328 already_enabled:
2329 error:
2330 free(filter_expression);
2331 free(filter);
2332 free(exclusion);
2333 channel_attr_destroy(attr);
2334 rcu_read_unlock();
2335 return ret;
2336 }
2337
2338 /*
2339 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2340 * We own filter, exclusion, and filter_expression.
2341 */
2342 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2343 char *channel_name, struct lttng_event *event,
2344 char *filter_expression,
2345 struct lttng_filter_bytecode *filter,
2346 struct lttng_event_exclusion *exclusion,
2347 int wpipe)
2348 {
2349 return _cmd_enable_event(session, domain, channel_name, event,
2350 filter_expression, filter, exclusion, wpipe, false);
2351 }
2352
2353 /*
2354 * Enable an event which is internal to LTTng. An internal should
2355 * never be made visible to clients and are immune to checks such as
2356 * reserved names.
2357 */
2358 static int cmd_enable_event_internal(struct ltt_session *session,
2359 struct lttng_domain *domain,
2360 char *channel_name, struct lttng_event *event,
2361 char *filter_expression,
2362 struct lttng_filter_bytecode *filter,
2363 struct lttng_event_exclusion *exclusion,
2364 int wpipe)
2365 {
2366 return _cmd_enable_event(session, domain, channel_name, event,
2367 filter_expression, filter, exclusion, wpipe, true);
2368 }
2369
2370 /*
2371 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2372 */
2373 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2374 struct lttng_event **events)
2375 {
2376 int ret;
2377 ssize_t nb_events = 0;
2378
2379 switch (domain) {
2380 case LTTNG_DOMAIN_KERNEL:
2381 nb_events = kernel_list_events(kernel_tracer_fd, events);
2382 if (nb_events < 0) {
2383 ret = LTTNG_ERR_KERN_LIST_FAIL;
2384 goto error;
2385 }
2386 break;
2387 case LTTNG_DOMAIN_UST:
2388 nb_events = ust_app_list_events(events);
2389 if (nb_events < 0) {
2390 ret = LTTNG_ERR_UST_LIST_FAIL;
2391 goto error;
2392 }
2393 break;
2394 case LTTNG_DOMAIN_LOG4J:
2395 case LTTNG_DOMAIN_JUL:
2396 case LTTNG_DOMAIN_PYTHON:
2397 nb_events = agent_list_events(events, domain);
2398 if (nb_events < 0) {
2399 ret = LTTNG_ERR_UST_LIST_FAIL;
2400 goto error;
2401 }
2402 break;
2403 default:
2404 ret = LTTNG_ERR_UND;
2405 goto error;
2406 }
2407
2408 return nb_events;
2409
2410 error:
2411 /* Return negative value to differentiate return code */
2412 return -ret;
2413 }
2414
2415 /*
2416 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2417 */
2418 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2419 struct lttng_event_field **fields)
2420 {
2421 int ret;
2422 ssize_t nb_fields = 0;
2423
2424 switch (domain) {
2425 case LTTNG_DOMAIN_UST:
2426 nb_fields = ust_app_list_event_fields(fields);
2427 if (nb_fields < 0) {
2428 ret = LTTNG_ERR_UST_LIST_FAIL;
2429 goto error;
2430 }
2431 break;
2432 case LTTNG_DOMAIN_KERNEL:
2433 default: /* fall-through */
2434 ret = LTTNG_ERR_UND;
2435 goto error;
2436 }
2437
2438 return nb_fields;
2439
2440 error:
2441 /* Return negative value to differentiate return code */
2442 return -ret;
2443 }
2444
2445 ssize_t cmd_list_syscalls(struct lttng_event **events)
2446 {
2447 return syscall_table_list(events);
2448 }
2449
2450 /*
2451 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2452 *
2453 * Called with session lock held.
2454 */
2455 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2456 enum lttng_domain_type domain, int32_t **pids)
2457 {
2458 int ret;
2459 ssize_t nr_pids = 0;
2460
2461 switch (domain) {
2462 case LTTNG_DOMAIN_KERNEL:
2463 {
2464 struct ltt_kernel_session *ksess;
2465
2466 ksess = session->kernel_session;
2467 nr_pids = kernel_list_tracker_pids(ksess, pids);
2468 if (nr_pids < 0) {
2469 ret = LTTNG_ERR_KERN_LIST_FAIL;
2470 goto error;
2471 }
2472 break;
2473 }
2474 case LTTNG_DOMAIN_UST:
2475 {
2476 struct ltt_ust_session *usess;
2477
2478 usess = session->ust_session;
2479 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2480 if (nr_pids < 0) {
2481 ret = LTTNG_ERR_UST_LIST_FAIL;
2482 goto error;
2483 }
2484 break;
2485 }
2486 case LTTNG_DOMAIN_LOG4J:
2487 case LTTNG_DOMAIN_JUL:
2488 case LTTNG_DOMAIN_PYTHON:
2489 default:
2490 ret = LTTNG_ERR_UND;
2491 goto error;
2492 }
2493
2494 return nr_pids;
2495
2496 error:
2497 /* Return negative value to differentiate return code */
2498 return -ret;
2499 }
2500
2501 static
2502 int domain_mkdir(const struct consumer_output *output,
2503 const struct ltt_session *session,
2504 uid_t uid, gid_t gid)
2505 {
2506 struct consumer_socket *socket;
2507 struct lttng_ht_iter iter;
2508 int ret;
2509 char *path = NULL;
2510
2511 if (!output || !output->socks) {
2512 ERR("No consumer output found");
2513 ret = -1;
2514 goto end;
2515 }
2516
2517 path = zmalloc(LTTNG_PATH_MAX * sizeof(char));
2518 if (!path) {
2519 ERR("Cannot allocate mkdir path");
2520 ret = -1;
2521 goto end;
2522 }
2523
2524 ret = snprintf(path, LTTNG_PATH_MAX, "%s%s%s",
2525 session_get_base_path(session),
2526 output->chunk_path, output->subdir);
2527 if (ret < 0 || ret >= LTTNG_PATH_MAX) {
2528 ERR("Format path");
2529 ret = -1;
2530 goto end;
2531 }
2532
2533 DBG("Domain mkdir %s for session %" PRIu64, path, session->id);
2534 rcu_read_lock();
2535 /*
2536 * We have to iterate to find a socket, but we only need to send the
2537 * rename command to one consumer, so we break after the first one.
2538 */
2539 cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
2540 pthread_mutex_lock(socket->lock);
2541 ret = consumer_mkdir(socket, session->id, output, path, uid, gid);
2542 pthread_mutex_unlock(socket->lock);
2543 if (ret) {
2544 ERR("Consumer mkdir");
2545 ret = -1;
2546 goto end_unlock;
2547 }
2548 break;
2549 }
2550
2551 ret = 0;
2552
2553 end_unlock:
2554 rcu_read_unlock();
2555 end:
2556 free(path);
2557 return ret;
2558 }
2559
2560 static
2561 int session_mkdir(const struct ltt_session *session)
2562 {
2563 int ret;
2564 struct consumer_output *output;
2565 uid_t uid;
2566 gid_t gid;
2567
2568 /*
2569 * Unsupported feature in lttng-relayd before 2.11, not an error since it
2570 * is only needed for session rotation and the user will get an error
2571 * on rotate.
2572 */
2573 if (session->consumer->type == CONSUMER_DST_NET &&
2574 session->consumer->relay_major_version == 2 &&
2575 session->consumer->relay_minor_version < 11) {
2576 ret = 0;
2577 goto end;
2578 }
2579
2580 if (session->kernel_session) {
2581 output = session->kernel_session->consumer;
2582 uid = session->kernel_session->uid;
2583 gid = session->kernel_session->gid;
2584 ret = domain_mkdir(output, session, uid, gid);
2585 if (ret) {
2586 ERR("Mkdir kernel");
2587 goto end;
2588 }
2589 }
2590
2591 if (session->ust_session) {
2592 output = session->ust_session->consumer;
2593 uid = session->ust_session->uid;
2594 gid = session->ust_session->gid;
2595 ret = domain_mkdir(output, session, uid, gid);
2596 if (ret) {
2597 ERR("Mkdir UST");
2598 goto end;
2599 }
2600 }
2601
2602 ret = 0;
2603
2604 end:
2605 return ret;
2606 }
2607
2608 /*
2609 * Command LTTNG_START_TRACE processed by the client thread.
2610 *
2611 * Called with session mutex held.
2612 */
2613 int cmd_start_trace(struct ltt_session *session)
2614 {
2615 int ret;
2616 unsigned long nb_chan = 0;
2617 struct ltt_kernel_session *ksession;
2618 struct ltt_ust_session *usess;
2619
2620 assert(session);
2621
2622 /* Ease our life a bit ;) */
2623 ksession = session->kernel_session;
2624 usess = session->ust_session;
2625
2626 /* Is the session already started? */
2627 if (session->active) {
2628 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2629 goto error;
2630 }
2631
2632 /*
2633 * Starting a session without channel is useless since after that it's not
2634 * possible to enable channel thus inform the client.
2635 */
2636 if (usess && usess->domain_global.channels) {
2637 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2638 }
2639 if (ksession) {
2640 nb_chan += ksession->channel_count;
2641 }
2642 if (!nb_chan) {
2643 ret = LTTNG_ERR_NO_CHANNEL;
2644 goto error;
2645 }
2646
2647 /*
2648 * Record the timestamp of the first time the session is started for
2649 * an eventual session rotation call.
2650 */
2651 if (!session->has_been_started) {
2652 session->current_chunk_start_ts = time(NULL);
2653 if (session->current_chunk_start_ts == (time_t) -1) {
2654 PERROR("Failed to retrieve the \"%s\" session's start time",
2655 session->name);
2656 ret = LTTNG_ERR_FATAL;
2657 goto error;
2658 }
2659 if (!session->snapshot_mode && session->output_traces) {
2660 ret = session_mkdir(session);
2661 if (ret) {
2662 ERR("Failed to create the session directories");
2663 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2664 goto error;
2665 }
2666 }
2667 }
2668
2669 /* Kernel tracing */
2670 if (ksession != NULL) {
2671 DBG("Start kernel tracing session %s", session->name);
2672 ret = start_kernel_session(ksession, kernel_tracer_fd);
2673 if (ret != LTTNG_OK) {
2674 goto error;
2675 }
2676 }
2677
2678 /* Flag session that trace should start automatically */
2679 if (usess) {
2680 /*
2681 * Even though the start trace might fail, flag this session active so
2682 * other application coming in are started by default.
2683 */
2684 usess->active = 1;
2685
2686 ret = ust_app_start_trace_all(usess);
2687 if (ret < 0) {
2688 ret = LTTNG_ERR_UST_START_FAIL;
2689 goto error;
2690 }
2691 }
2692
2693 /* Flag this after a successful start. */
2694 session->has_been_started = 1;
2695 session->active = 1;
2696
2697 /*
2698 * Clear the flag that indicates that a rotation was done while the
2699 * session was stopped.
2700 */
2701 session->rotated_after_last_stop = false;
2702
2703 if (session->rotate_timer_period) {
2704 ret = timer_session_rotation_schedule_timer_start(session,
2705 session->rotate_timer_period);
2706 if (ret < 0) {
2707 ERR("Failed to enable rotate timer");
2708 ret = LTTNG_ERR_UNK;
2709 goto error;
2710 }
2711 }
2712
2713 ret = LTTNG_OK;
2714
2715 error:
2716 return ret;
2717 }
2718
2719 static
2720 int rename_active_chunk(struct ltt_session *session)
2721 {
2722 int ret;
2723
2724 session->current_archive_id++;
2725
2726 /*
2727 * The currently active tracing path is now the folder we
2728 * want to rename.
2729 */
2730 ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
2731 session->rotation_chunk.active_tracing_path,
2732 sizeof(session->rotation_chunk.current_rotate_path));
2733 if (ret) {
2734 ERR("Failed to copy active tracing path");
2735 goto end;
2736 }
2737
2738 ret = rename_completed_chunk(session, time(NULL));
2739 if (ret < 0) {
2740 ERR("Failed to rename current rotation's path");
2741 goto end;
2742 }
2743
2744 /*
2745 * We just renamed, the folder, we didn't do an actual rotation, so
2746 * the active tracing path is now the renamed folder and we have to
2747 * restore the rotate count.
2748 */
2749 ret = lttng_strncpy(session->rotation_chunk.active_tracing_path,
2750 session->rotation_chunk.current_rotate_path,
2751 sizeof(session->rotation_chunk.active_tracing_path));
2752 if (ret) {
2753 ERR("Failed to rename active session chunk tracing path");
2754 goto end;
2755 }
2756 end:
2757 session->current_archive_id--;
2758 return ret;
2759 }
2760
2761 /*
2762 * Command LTTNG_STOP_TRACE processed by the client thread.
2763 */
2764 int cmd_stop_trace(struct ltt_session *session)
2765 {
2766 int ret;
2767 struct ltt_kernel_channel *kchan;
2768 struct ltt_kernel_session *ksession;
2769 struct ltt_ust_session *usess;
2770 bool error_occured = false;
2771
2772 assert(session);
2773
2774 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2775 /* Short cut */
2776 ksession = session->kernel_session;
2777 usess = session->ust_session;
2778
2779 /* Session is not active. Skip everythong and inform the client. */
2780 if (!session->active) {
2781 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2782 goto error;
2783 }
2784
2785 if (session->rotation_pending_check_timer_enabled) {
2786 if (timer_session_rotation_pending_check_stop(session)) {
2787 ERR("Failed to stop the \"rotation pending check\" timer of session %s",
2788 session->name);
2789 }
2790 }
2791
2792 if (session->rotation_schedule_timer_enabled) {
2793 if (timer_session_rotation_schedule_timer_stop(
2794 session)) {
2795 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
2796 session->name);
2797 }
2798 }
2799
2800 if (session->current_archive_id > 0 &&
2801 session->rotation_state != LTTNG_ROTATION_STATE_ONGOING) {
2802 ret = rename_active_chunk(session);
2803 if (ret) {
2804 /*
2805 * This error should not prevent the user from stopping
2806 * the session. However, it will be reported at the end.
2807 */
2808 error_occured = true;
2809 }
2810 }
2811
2812 /* Kernel tracer */
2813 if (ksession && ksession->active) {
2814 DBG("Stop kernel tracing");
2815
2816 ret = kernel_stop_session(ksession);
2817 if (ret < 0) {
2818 ret = LTTNG_ERR_KERN_STOP_FAIL;
2819 goto error;
2820 }
2821
2822 kernel_wait_quiescent(kernel_tracer_fd);
2823
2824 /* Flush metadata after stopping (if exists) */
2825 if (ksession->metadata_stream_fd >= 0) {
2826 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2827 if (ret < 0) {
2828 ERR("Kernel metadata flush failed");
2829 }
2830 }
2831
2832 /* Flush all buffers after stopping */
2833 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2834 ret = kernel_flush_buffer(kchan);
2835 if (ret < 0) {
2836 ERR("Kernel flush buffer error");
2837 }
2838 }
2839
2840 ksession->active = 0;
2841 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2842 session->id);
2843 }
2844
2845 if (usess && usess->active) {
2846 /*
2847 * Even though the stop trace might fail, flag this session inactive so
2848 * other application coming in are not started by default.
2849 */
2850 usess->active = 0;
2851
2852 ret = ust_app_stop_trace_all(usess);
2853 if (ret < 0) {
2854 ret = LTTNG_ERR_UST_STOP_FAIL;
2855 goto error;
2856 }
2857 }
2858
2859 /* Flag inactive after a successful stop. */
2860 session->active = 0;
2861 ret = !error_occured ? LTTNG_OK : LTTNG_ERR_UNK;
2862
2863 error:
2864 return ret;
2865 }
2866
2867 /*
2868 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2869 */
2870 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2871 struct lttng_uri *uris)
2872 {
2873 int ret, i;
2874 struct ltt_kernel_session *ksess = session->kernel_session;
2875 struct ltt_ust_session *usess = session->ust_session;
2876
2877 assert(session);
2878 assert(uris);
2879 assert(nb_uri > 0);
2880
2881 /* Can't set consumer URI if the session is active. */
2882 if (session->active) {
2883 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2884 goto error;
2885 }
2886
2887 /* Set the "global" consumer URIs */
2888 for (i = 0; i < nb_uri; i++) {
2889 ret = add_uri_to_consumer(session->consumer,
2890 &uris[i], 0, session->name);
2891 if (ret != LTTNG_OK) {
2892 goto error;
2893 }
2894 }
2895
2896 /* Set UST session URIs */
2897 if (session->ust_session) {
2898 for (i = 0; i < nb_uri; i++) {
2899 ret = add_uri_to_consumer(
2900 session->ust_session->consumer,
2901 &uris[i], LTTNG_DOMAIN_UST,
2902 session->name);
2903 if (ret != LTTNG_OK) {
2904 goto error;
2905 }
2906 }
2907 }
2908
2909 /* Set kernel session URIs */
2910 if (session->kernel_session) {
2911 for (i = 0; i < nb_uri; i++) {
2912 ret = add_uri_to_consumer(
2913 session->kernel_session->consumer,
2914 &uris[i], LTTNG_DOMAIN_KERNEL,
2915 session->name);
2916 if (ret != LTTNG_OK) {
2917 goto error;
2918 }
2919 }
2920 }
2921
2922 /*
2923 * Make sure to set the session in output mode after we set URI since a
2924 * session can be created without URL (thus flagged in no output mode).
2925 */
2926 session->output_traces = 1;
2927 if (ksess) {
2928 ksess->output_traces = 1;
2929 }
2930
2931 if (usess) {
2932 usess->output_traces = 1;
2933 }
2934
2935 /* All good! */
2936 ret = LTTNG_OK;
2937
2938 error:
2939 return ret;
2940 }
2941
2942 /*
2943 * Command LTTNG_CREATE_SESSION processed by the client thread.
2944 */
2945 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
2946 size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
2947 {
2948 int ret;
2949 struct ltt_session *session;
2950
2951 assert(name);
2952 assert(creds);
2953
2954 /*
2955 * Verify if the session already exist
2956 *
2957 * XXX: There is no need for the session lock list here since the caller
2958 * (process_client_msg) is holding it. We might want to change that so a
2959 * single command does not lock the entire session list.
2960 */
2961 session = session_find_by_name(name);
2962 if (session != NULL) {
2963 ret = LTTNG_ERR_EXIST_SESS;
2964 goto find_error;
2965 }
2966
2967 /* Create tracing session in the registry */
2968 ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
2969 LTTNG_SOCK_GET_GID_CRED(creds));
2970 if (ret != LTTNG_OK) {
2971 goto session_error;
2972 }
2973
2974 /*
2975 * Get the newly created session pointer back
2976 *
2977 * XXX: There is no need for the session lock list here since the caller
2978 * (process_client_msg) is holding it. We might want to change that so a
2979 * single command does not lock the entire session list.
2980 */
2981 session = session_find_by_name(name);
2982 assert(session);
2983
2984 session->live_timer = live_timer;
2985 /* Create default consumer output for the session not yet created. */
2986 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
2987 if (session->consumer == NULL) {
2988 ret = LTTNG_ERR_FATAL;
2989 goto consumer_error;
2990 }
2991
2992 if (uris) {
2993 ret = cmd_set_consumer_uri(session, nb_uri, uris);
2994 if (ret != LTTNG_OK) {
2995 goto consumer_error;
2996 }
2997 session->output_traces = 1;
2998 } else {
2999 session->output_traces = 0;
3000 DBG2("Session %s created with no output", session->name);
3001 }
3002
3003 session->consumer->enabled = 1;
3004
3005 return LTTNG_OK;
3006
3007 consumer_error:
3008 session_destroy(session);
3009 session_error:
3010 find_error:
3011 return ret;
3012 }
3013
3014 /*
3015 * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
3016 */
3017 int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
3018 size_t nb_uri, lttng_sock_cred *creds)
3019 {
3020 int ret;
3021 struct ltt_session *session;
3022 struct snapshot_output *new_output = NULL;
3023
3024 assert(name);
3025 assert(creds);
3026
3027 /*
3028 * Create session in no output mode with URIs set to NULL. The uris we've
3029 * received are for a default snapshot output if one.
3030 */
3031 ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
3032 if (ret != LTTNG_OK) {
3033 goto error;
3034 }
3035
3036 /* Get the newly created session pointer back. This should NEVER fail. */
3037 session = session_find_by_name(name);
3038 assert(session);
3039
3040 /* Flag session for snapshot mode. */
3041 session->snapshot_mode = 1;
3042
3043 /* Skip snapshot output creation if no URI is given. */
3044 if (nb_uri == 0) {
3045 goto end;
3046 }
3047
3048 new_output = snapshot_output_alloc();
3049 if (!new_output) {
3050 ret = LTTNG_ERR_NOMEM;
3051 goto error_snapshot_alloc;
3052 }
3053
3054 ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
3055 uris, nb_uri, session->consumer, new_output, &session->snapshot);
3056 if (ret < 0) {
3057 if (ret == -ENOMEM) {
3058 ret = LTTNG_ERR_NOMEM;
3059 } else {
3060 ret = LTTNG_ERR_INVALID;
3061 }
3062 goto error_snapshot;
3063 }
3064
3065 rcu_read_lock();
3066 snapshot_add_output(&session->snapshot, new_output);
3067 rcu_read_unlock();
3068
3069 end:
3070 return LTTNG_OK;
3071
3072 error_snapshot:
3073 snapshot_output_destroy(new_output);
3074 error_snapshot_alloc:
3075 session_destroy(session);
3076 error:
3077 return ret;
3078 }
3079
3080 /*
3081 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3082 *
3083 * Called with session lock held.
3084 */
3085 int cmd_destroy_session(struct ltt_session *session, int wpipe,
3086 struct notification_thread_handle *notification_thread_handle)
3087 {
3088 int ret;
3089 struct ltt_ust_session *usess;
3090 struct ltt_kernel_session *ksess;
3091
3092 /* Safety net */
3093 assert(session);
3094
3095 usess = session->ust_session;
3096 ksess = session->kernel_session;
3097
3098 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
3099
3100 if (session->rotation_pending_check_timer_enabled) {
3101 if (timer_session_rotation_pending_check_stop(session)) {
3102 ERR("Failed to stop the \"rotation pending check\" timer of session %s",
3103 session->name);
3104 }
3105 }
3106
3107 if (session->rotation_schedule_timer_enabled) {
3108 if (timer_session_rotation_schedule_timer_stop(
3109 session)) {
3110 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3111 session->name);
3112 }
3113 }
3114
3115 if (session->rotate_size) {
3116 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3117 session->rotate_size = 0;
3118 }
3119
3120 /*
3121 * The rename of the current chunk is performed at stop, but if we rotated
3122 * the session after the previous stop command, we need to rename the
3123 * new (and empty) chunk that was started in between.
3124 */
3125 if (session->rotated_after_last_stop) {
3126 rename_active_chunk(session);
3127 }
3128
3129 /* Clean kernel session teardown */
3130 kernel_destroy_session(ksess);
3131
3132 /* UST session teardown */
3133 if (usess) {
3134 /* Close any relayd session */
3135 consumer_output_send_destroy_relayd(usess->consumer);
3136
3137 /* Destroy every UST application related to this session. */
3138 ret = ust_app_destroy_trace_all(usess);
3139 if (ret) {
3140 ERR("Error in ust_app_destroy_trace_all");
3141 }
3142
3143 /* Clean up the rest. */
3144 trace_ust_destroy_session(usess);
3145 }
3146
3147 /*
3148 * Must notify the kernel thread here to update it's poll set in order to
3149 * remove the channel(s)' fd just destroyed.
3150 */
3151 ret = notify_thread_pipe(wpipe);
3152 if (ret < 0) {
3153 PERROR("write kernel poll pipe");
3154 }
3155
3156 if (session->shm_path[0]) {
3157 /*
3158 * When a session is created with an explicit shm_path,
3159 * the consumer daemon will create its shared memory files
3160 * at that location and will *not* unlink them. This is normal
3161 * as the intention of that feature is to make it possible
3162 * to retrieve the content of those files should a crash occur.
3163 *
3164 * To ensure the content of those files can be used, the
3165 * sessiond daemon will replicate the content of the metadata
3166 * cache in a metadata file.
3167 *
3168 * On clean-up, it is expected that the consumer daemon will
3169 * unlink the shared memory files and that the session daemon
3170 * will unlink the metadata file. Then, the session's directory
3171 * in the shm path can be removed.
3172 *
3173 * Unfortunately, a flaw in the design of the sessiond's and
3174 * consumerd's tear down of channels makes it impossible to
3175 * determine when the sessiond _and_ the consumerd have both
3176 * destroyed their representation of a channel. For one, the
3177 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3178 * callbacks in both daemons.
3179 *
3180 * However, it is also impossible for the sessiond to know when
3181 * the consumer daemon is done destroying its channel(s) since
3182 * it occurs as a reaction to the closing of the channel's file
3183 * descriptor. There is no resulting communication initiated
3184 * from the consumerd to the sessiond to confirm that the
3185 * operation is completed (and was successful).
3186 *
3187 * Until this is all fixed, the session daemon checks for the
3188 * removal of the session's shm path which makes it possible
3189 * to safely advertise a session as having been destroyed.
3190 *
3191 * Prior to this fix, it was not possible to reliably save
3192 * a session making use of the --shm-path option, destroy it,
3193 * and load it again. This is because the creation of the
3194 * session would fail upon seeing the session's shm path
3195 * already in existence.
3196 *
3197 * Note that none of the error paths in the check for the
3198 * directory's existence return an error. This is normal
3199 * as there isn't much that can be done. The session will
3200 * be destroyed properly, except that we can't offer the
3201 * guarantee that the same session can be re-created.
3202 */
3203 current_completion_handler = &destroy_completion_handler.handler;
3204 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3205 session->shm_path,
3206 sizeof(destroy_completion_handler.shm_path));
3207 assert(!ret);
3208 }
3209 ret = session_destroy(session);
3210
3211 return ret;
3212 }
3213
3214 /*
3215 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3216 */
3217 int cmd_register_consumer(struct ltt_session *session,
3218 enum lttng_domain_type domain, const char *sock_path,
3219 struct consumer_data *cdata)
3220 {
3221 int ret, sock;
3222 struct consumer_socket *socket = NULL;
3223
3224 assert(session);
3225 assert(cdata);
3226 assert(sock_path);
3227
3228 switch (domain) {
3229 case LTTNG_DOMAIN_KERNEL:
3230 {
3231 struct ltt_kernel_session *ksess = session->kernel_session;
3232
3233 assert(ksess);
3234
3235 /* Can't register a consumer if there is already one */
3236 if (ksess->consumer_fds_sent != 0) {
3237 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3238 goto error;
3239 }
3240
3241 sock = lttcomm_connect_unix_sock(sock_path);
3242 if (sock < 0) {
3243 ret = LTTNG_ERR_CONNECT_FAIL;
3244 goto error;
3245 }
3246 cdata->cmd_sock = sock;
3247
3248 socket = consumer_allocate_socket(&cdata->cmd_sock);
3249 if (socket == NULL) {
3250 ret = close(sock);
3251 if (ret < 0) {
3252 PERROR("close register consumer");
3253 }
3254 cdata->cmd_sock = -1;
3255 ret = LTTNG_ERR_FATAL;
3256 goto error;
3257 }
3258
3259 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3260 if (socket->lock == NULL) {
3261 PERROR("zmalloc pthread mutex");
3262 ret = LTTNG_ERR_FATAL;
3263 goto error;
3264 }
3265 pthread_mutex_init(socket->lock, NULL);
3266 socket->registered = 1;