b668b56d48f90559ff3b63bc61723993dc8c23a7
[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 #include <stdio.h>
26
27 #include <common/defaults.h>
28 #include <common/common.h>
29 #include <common/sessiond-comm/sessiond-comm.h>
30 #include <common/relayd/relayd.h>
31 #include <common/utils.h>
32 #include <common/compat/string.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/dynamic-buffer.h>
35 #include <common/buffer-view.h>
36 #include <common/trace-chunk.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/trigger/trigger-internal.h>
39 #include <lttng/condition/condition.h>
40 #include <lttng/action/action.h>
41 #include <lttng/channel.h>
42 #include <lttng/channel-internal.h>
43 #include <lttng/rotate-internal.h>
44 #include <lttng/location-internal.h>
45 #include <lttng/session-internal.h>
46 #include <lttng/userspace-probe-internal.h>
47 #include <lttng/session-descriptor-internal.h>
48 #include <common/string-utils/string-utils.h>
49
50 #include "channel.h"
51 #include "consumer.h"
52 #include "event.h"
53 #include "health-sessiond.h"
54 #include "kernel.h"
55 #include "kernel-consumer.h"
56 #include "lttng-sessiond.h"
57 #include "utils.h"
58 #include "lttng-syscall.h"
59 #include "agent.h"
60 #include "buffer-registry.h"
61 #include "notification-thread.h"
62 #include "notification-thread-commands.h"
63 #include "rotate.h"
64 #include "rotation-thread.h"
65 #include "timer.h"
66 #include "agent-thread.h"
67
68 #include "cmd.h"
69
70 /* Sleep for 100ms between each check for the shm path's deletion. */
71 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
72
73 struct cmd_destroy_session_reply_context {
74 int reply_sock_fd;
75 bool implicit_rotation_on_destroy;
76 /*
77 * Indicates whether or not an error occurred while launching the
78 * destruction of a session.
79 */
80 enum lttng_error_code destruction_status;
81 };
82
83 static enum lttng_error_code wait_on_path(void *path);
84
85 /*
86 * Command completion handler that is used by the destroy command
87 * when a session that has a non-default shm_path is being destroyed.
88 *
89 * See comment in cmd_destroy_session() for the rationale.
90 */
91 static struct destroy_completion_handler {
92 struct cmd_completion_handler handler;
93 char shm_path[member_sizeof(struct ltt_session, shm_path)];
94 } destroy_completion_handler = {
95 .handler = {
96 .run = wait_on_path,
97 .data = destroy_completion_handler.shm_path
98 },
99 .shm_path = { 0 },
100 };
101
102 static struct cmd_completion_handler *current_completion_handler;
103
104 /*
105 * Used to keep a unique index for each relayd socket created where this value
106 * is associated with streams on the consumer so it can match the right relayd
107 * to send to. It must be accessed with the relayd_net_seq_idx_lock
108 * held.
109 */
110 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
111 static uint64_t relayd_net_seq_idx;
112
113 static int validate_ust_event_name(const char *);
114 static int cmd_enable_event_internal(struct ltt_session *session,
115 const struct lttng_domain *domain,
116 char *channel_name, struct lttng_event *event,
117 char *filter_expression,
118 struct lttng_filter_bytecode *filter,
119 struct lttng_event_exclusion *exclusion,
120 int wpipe);
121
122 /*
123 * Create a session path used by list_lttng_sessions for the case that the
124 * session consumer is on the network.
125 */
126 static int build_network_session_path(char *dst, size_t size,
127 struct ltt_session *session)
128 {
129 int ret, kdata_port, udata_port;
130 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
131 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
132
133 assert(session);
134 assert(dst);
135
136 memset(tmp_urls, 0, sizeof(tmp_urls));
137 memset(tmp_uurl, 0, sizeof(tmp_uurl));
138
139 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
140
141 if (session->kernel_session && session->kernel_session->consumer) {
142 kuri = &session->kernel_session->consumer->dst.net.control;
143 kdata_port = session->kernel_session->consumer->dst.net.data.port;
144 }
145
146 if (session->ust_session && session->ust_session->consumer) {
147 uuri = &session->ust_session->consumer->dst.net.control;
148 udata_port = session->ust_session->consumer->dst.net.data.port;
149 }
150
151 if (uuri == NULL && kuri == NULL) {
152 uri = &session->consumer->dst.net.control;
153 kdata_port = session->consumer->dst.net.data.port;
154 } else if (kuri && uuri) {
155 ret = uri_compare(kuri, uuri);
156 if (ret) {
157 /* Not Equal */
158 uri = kuri;
159 /* Build uuri URL string */
160 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
161 if (ret < 0) {
162 goto error;
163 }
164 } else {
165 uri = kuri;
166 }
167 } else if (kuri && uuri == NULL) {
168 uri = kuri;
169 } else if (uuri && kuri == NULL) {
170 uri = uuri;
171 }
172
173 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
174 if (ret < 0) {
175 goto error;
176 }
177
178 /*
179 * Do we have a UST url set. If yes, this means we have both kernel and UST
180 * to print.
181 */
182 if (*tmp_uurl != '\0') {
183 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
184 tmp_urls, kdata_port, tmp_uurl, udata_port);
185 } else {
186 int dport;
187 if (kuri || (!kuri && !uuri)) {
188 dport = kdata_port;
189 } else {
190 /* No kernel URI, use the UST port. */
191 dport = udata_port;
192 }
193 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
194 }
195
196 error:
197 return ret;
198 }
199
200 /*
201 * Get run-time attributes if the session has been started (discarded events,
202 * lost packets).
203 */
204 static int get_kernel_runtime_stats(struct ltt_session *session,
205 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
206 uint64_t *lost_packets)
207 {
208 int ret;
209
210 if (!session->has_been_started) {
211 ret = 0;
212 *discarded_events = 0;
213 *lost_packets = 0;
214 goto end;
215 }
216
217 ret = consumer_get_discarded_events(session->id, kchan->key,
218 session->kernel_session->consumer,
219 discarded_events);
220 if (ret < 0) {
221 goto end;
222 }
223
224 ret = consumer_get_lost_packets(session->id, kchan->key,
225 session->kernel_session->consumer,
226 lost_packets);
227 if (ret < 0) {
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Get run-time attributes if the session has been started (discarded events,
237 * lost packets).
238 */
239 static int get_ust_runtime_stats(struct ltt_session *session,
240 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
241 uint64_t *lost_packets)
242 {
243 int ret;
244 struct ltt_ust_session *usess;
245
246 if (!discarded_events || !lost_packets) {
247 ret = -1;
248 goto end;
249 }
250
251 usess = session->ust_session;
252 assert(discarded_events);
253 assert(lost_packets);
254
255 if (!usess || !session->has_been_started) {
256 *discarded_events = 0;
257 *lost_packets = 0;
258 ret = 0;
259 goto end;
260 }
261
262 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
263 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
264 &usess->buffer_reg_uid_list,
265 usess->consumer, uchan->id,
266 uchan->attr.overwrite,
267 discarded_events,
268 lost_packets);
269 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
270 ret = ust_app_pid_get_channel_runtime_stats(usess,
271 uchan, usess->consumer,
272 uchan->attr.overwrite,
273 discarded_events,
274 lost_packets);
275 if (ret < 0) {
276 goto end;
277 }
278 *discarded_events += uchan->per_pid_closed_app_discarded;
279 *lost_packets += uchan->per_pid_closed_app_lost;
280 } else {
281 ERR("Unsupported buffer type");
282 assert(0);
283 ret = -1;
284 goto end;
285 }
286
287 end:
288 return ret;
289 }
290
291 /*
292 * Fill lttng_channel array of all channels.
293 */
294 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
295 struct ltt_session *session, struct lttng_channel *channels,
296 struct lttng_channel_extended *chan_exts)
297 {
298 int i = 0, ret = 0;
299 struct ltt_kernel_channel *kchan;
300
301 DBG("Listing channels for session %s", session->name);
302
303 switch (domain) {
304 case LTTNG_DOMAIN_KERNEL:
305 /* Kernel channels */
306 if (session->kernel_session != NULL) {
307 cds_list_for_each_entry(kchan,
308 &session->kernel_session->channel_list.head, list) {
309 uint64_t discarded_events, lost_packets;
310 struct lttng_channel_extended *extended;
311
312 extended = (struct lttng_channel_extended *)
313 kchan->channel->attr.extended.ptr;
314
315 ret = get_kernel_runtime_stats(session, kchan,
316 &discarded_events, &lost_packets);
317 if (ret < 0) {
318 goto end;
319 }
320 /* Copy lttng_channel struct to array */
321 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
322 channels[i].enabled = kchan->enabled;
323 chan_exts[i].discarded_events =
324 discarded_events;
325 chan_exts[i].lost_packets = lost_packets;
326 chan_exts[i].monitor_timer_interval =
327 extended->monitor_timer_interval;
328 chan_exts[i].blocking_timeout = 0;
329 i++;
330 }
331 }
332 break;
333 case LTTNG_DOMAIN_UST:
334 {
335 struct lttng_ht_iter iter;
336 struct ltt_ust_channel *uchan;
337
338 rcu_read_lock();
339 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
340 &iter.iter, uchan, node.node) {
341 uint64_t discarded_events = 0, lost_packets = 0;
342
343 if (lttng_strncpy(channels[i].name, uchan->name,
344 LTTNG_SYMBOL_NAME_LEN)) {
345 break;
346 }
347 channels[i].attr.overwrite = uchan->attr.overwrite;
348 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
349 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
350 channels[i].attr.switch_timer_interval =
351 uchan->attr.switch_timer_interval;
352 channels[i].attr.read_timer_interval =
353 uchan->attr.read_timer_interval;
354 channels[i].enabled = uchan->enabled;
355 channels[i].attr.tracefile_size = uchan->tracefile_size;
356 channels[i].attr.tracefile_count = uchan->tracefile_count;
357
358 /*
359 * Map enum lttng_ust_output to enum lttng_event_output.
360 */
361 switch (uchan->attr.output) {
362 case LTTNG_UST_MMAP:
363 channels[i].attr.output = LTTNG_EVENT_MMAP;
364 break;
365 default:
366 /*
367 * LTTNG_UST_MMAP is the only supported UST
368 * output mode.
369 */
370 assert(0);
371 break;
372 }
373
374 chan_exts[i].monitor_timer_interval =
375 uchan->monitor_timer_interval;
376 chan_exts[i].blocking_timeout =
377 uchan->attr.u.s.blocking_timeout;
378
379 ret = get_ust_runtime_stats(session, uchan,
380 &discarded_events, &lost_packets);
381 if (ret < 0) {
382 break;
383 }
384 chan_exts[i].discarded_events = discarded_events;
385 chan_exts[i].lost_packets = lost_packets;
386 i++;
387 }
388 rcu_read_unlock();
389 break;
390 }
391 default:
392 break;
393 }
394
395 end:
396 if (ret < 0) {
397 return -LTTNG_ERR_FATAL;
398 } else {
399 return LTTNG_OK;
400 }
401 }
402
403 static int increment_extended_len(const char *filter_expression,
404 struct lttng_event_exclusion *exclusion,
405 const struct lttng_userspace_probe_location *probe_location,
406 size_t *extended_len)
407 {
408 int ret = 0;
409
410 *extended_len += sizeof(struct lttcomm_event_extended_header);
411
412 if (filter_expression) {
413 *extended_len += strlen(filter_expression) + 1;
414 }
415
416 if (exclusion) {
417 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
418 }
419
420 if (probe_location) {
421 ret = lttng_userspace_probe_location_serialize(probe_location,
422 NULL, NULL);
423 if (ret < 0) {
424 goto end;
425 }
426 *extended_len += ret;
427 }
428 ret = 0;
429 end:
430 return ret;
431 }
432
433 static int append_extended_info(const char *filter_expression,
434 struct lttng_event_exclusion *exclusion,
435 struct lttng_userspace_probe_location *probe_location,
436 void **extended_at)
437 {
438 int ret = 0;
439 size_t filter_len = 0;
440 size_t nb_exclusions = 0;
441 size_t userspace_probe_location_len = 0;
442 struct lttng_dynamic_buffer location_buffer;
443 struct lttcomm_event_extended_header extended_header;
444
445 if (filter_expression) {
446 filter_len = strlen(filter_expression) + 1;
447 }
448
449 if (exclusion) {
450 nb_exclusions = exclusion->count;
451 }
452
453 if (probe_location) {
454 lttng_dynamic_buffer_init(&location_buffer);
455 ret = lttng_userspace_probe_location_serialize(probe_location,
456 &location_buffer, NULL);
457 if (ret < 0) {
458 ret = -1;
459 goto end;
460 }
461 userspace_probe_location_len = location_buffer.size;
462 }
463
464 /* Set header fields */
465 extended_header.filter_len = filter_len;
466 extended_header.nb_exclusions = nb_exclusions;
467 extended_header.userspace_probe_location_len = userspace_probe_location_len;
468
469 /* Copy header */
470 memcpy(*extended_at, &extended_header, sizeof(extended_header));
471 *extended_at += sizeof(extended_header);
472
473 /* Copy filter string */
474 if (filter_expression) {
475 memcpy(*extended_at, filter_expression, filter_len);
476 *extended_at += filter_len;
477 }
478
479 /* Copy exclusion names */
480 if (exclusion) {
481 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
482
483 memcpy(*extended_at, &exclusion->names, len);
484 *extended_at += len;
485 }
486
487 if (probe_location) {
488 memcpy(*extended_at, location_buffer.data, location_buffer.size);
489 *extended_at += location_buffer.size;
490 lttng_dynamic_buffer_reset(&location_buffer);
491 }
492 ret = 0;
493 end:
494 return ret;
495 }
496
497 /*
498 * Create a list of agent domain events.
499 *
500 * Return number of events in list on success or else a negative value.
501 */
502 static int list_lttng_agent_events(struct agent *agt,
503 struct lttng_event **events, size_t *total_size)
504 {
505 int i = 0, ret = 0;
506 unsigned int nb_event = 0;
507 struct agent_event *event;
508 struct lttng_event *tmp_events = NULL;
509 struct lttng_ht_iter iter;
510 size_t extended_len = 0;
511 void *extended_at;
512
513 assert(agt);
514 assert(events);
515
516 DBG3("Listing agent events");
517
518 rcu_read_lock();
519 nb_event = lttng_ht_get_count(agt->events);
520 rcu_read_unlock();
521 if (nb_event == 0) {
522 ret = nb_event;
523 *total_size = 0;
524 goto error;
525 }
526
527 /* Compute required extended infos size */
528 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
529
530 /*
531 * This is only valid because the commands which add events are
532 * processed in the same thread as the listing.
533 */
534 rcu_read_lock();
535 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
536 ret = increment_extended_len(event->filter_expression, NULL, NULL,
537 &extended_len);
538 if (ret) {
539 DBG("Error computing the length of extended info message");
540 ret = -LTTNG_ERR_FATAL;
541 goto error;
542 }
543 }
544 rcu_read_unlock();
545
546 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
547 tmp_events = zmalloc(*total_size);
548 if (!tmp_events) {
549 PERROR("zmalloc agent events session");
550 ret = -LTTNG_ERR_FATAL;
551 goto error;
552 }
553
554 extended_at = ((uint8_t *) tmp_events) +
555 nb_event * sizeof(struct lttng_event);
556
557 rcu_read_lock();
558 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
559 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
560 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
561 tmp_events[i].enabled = event->enabled;
562 tmp_events[i].loglevel = event->loglevel_value;
563 tmp_events[i].loglevel_type = event->loglevel_type;
564 i++;
565
566 /* Append extended info */
567 ret = append_extended_info(event->filter_expression, NULL, NULL,
568 &extended_at);
569 if (ret) {
570 DBG("Error appending extended info message");
571 ret = -LTTNG_ERR_FATAL;
572 goto error;
573 }
574 }
575
576 *events = tmp_events;
577 ret = nb_event;
578 assert(nb_event == i);
579
580 end:
581 rcu_read_unlock();
582 return ret;
583 error:
584 free(tmp_events);
585 goto end;
586 }
587
588 /*
589 * Create a list of ust global domain events.
590 */
591 static int list_lttng_ust_global_events(char *channel_name,
592 struct ltt_ust_domain_global *ust_global,
593 struct lttng_event **events, size_t *total_size)
594 {
595 int i = 0, ret = 0;
596 unsigned int nb_event = 0;
597 struct lttng_ht_iter iter;
598 struct lttng_ht_node_str *node;
599 struct ltt_ust_channel *uchan;
600 struct ltt_ust_event *uevent;
601 struct lttng_event *tmp;
602 size_t extended_len = 0;
603 void *extended_at;
604
605 DBG("Listing UST global events for channel %s", channel_name);
606
607 rcu_read_lock();
608
609 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
610 node = lttng_ht_iter_get_node_str(&iter);
611 if (node == NULL) {
612 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
613 goto end;
614 }
615
616 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
617
618 nb_event = lttng_ht_get_count(uchan->events);
619 if (nb_event == 0) {
620 ret = nb_event;
621 *total_size = 0;
622 goto end;
623 }
624
625 DBG3("Listing UST global %d events", nb_event);
626
627 /* Compute required extended infos size */
628 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
629 if (uevent->internal) {
630 nb_event--;
631 continue;
632 }
633
634 ret = increment_extended_len(uevent->filter_expression,
635 uevent->exclusion, NULL, &extended_len);
636 if (ret) {
637 DBG("Error computing the length of extended info message");
638 ret = -LTTNG_ERR_FATAL;
639 goto end;
640 }
641 }
642 if (nb_event == 0) {
643 /* All events are internal, skip. */
644 ret = 0;
645 *total_size = 0;
646 goto end;
647 }
648
649 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
650 tmp = zmalloc(*total_size);
651 if (tmp == NULL) {
652 ret = -LTTNG_ERR_FATAL;
653 goto end;
654 }
655
656 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
657
658 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
659 if (uevent->internal) {
660 /* This event should remain hidden from clients */
661 continue;
662 }
663 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
664 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
665 tmp[i].enabled = uevent->enabled;
666
667 switch (uevent->attr.instrumentation) {
668 case LTTNG_UST_TRACEPOINT:
669 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
670 break;
671 case LTTNG_UST_PROBE:
672 tmp[i].type = LTTNG_EVENT_PROBE;
673 break;
674 case LTTNG_UST_FUNCTION:
675 tmp[i].type = LTTNG_EVENT_FUNCTION;
676 break;
677 }
678
679 tmp[i].loglevel = uevent->attr.loglevel;
680 switch (uevent->attr.loglevel_type) {
681 case LTTNG_UST_LOGLEVEL_ALL:
682 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
683 break;
684 case LTTNG_UST_LOGLEVEL_RANGE:
685 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
686 break;
687 case LTTNG_UST_LOGLEVEL_SINGLE:
688 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
689 break;
690 }
691 if (uevent->filter) {
692 tmp[i].filter = 1;
693 }
694 if (uevent->exclusion) {
695 tmp[i].exclusion = 1;
696 }
697 i++;
698
699 /* Append extended info */
700 ret = append_extended_info(uevent->filter_expression,
701 uevent->exclusion, NULL, &extended_at);
702 if (ret) {
703 DBG("Error appending extended info message");
704 ret = -LTTNG_ERR_FATAL;
705 goto end;
706 }
707 }
708
709 ret = nb_event;
710 *events = tmp;
711 end:
712 rcu_read_unlock();
713 return ret;
714 }
715
716 /*
717 * Fill lttng_event array of all kernel events in the channel.
718 */
719 static int list_lttng_kernel_events(char *channel_name,
720 struct ltt_kernel_session *kernel_session,
721 struct lttng_event **events, size_t *total_size)
722 {
723 int i = 0, ret;
724 unsigned int nb_event;
725 struct ltt_kernel_event *event;
726 struct ltt_kernel_channel *kchan;
727 size_t extended_len = 0;
728 void *extended_at;
729
730 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
731 if (kchan == NULL) {
732 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
733 goto error;
734 }
735
736 nb_event = kchan->event_count;
737
738 DBG("Listing events for channel %s", kchan->channel->name);
739
740 if (nb_event == 0) {
741 *total_size = 0;
742 *events = NULL;
743 goto end;
744 }
745
746 /* Compute required extended infos size */
747 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
748 ret = increment_extended_len(event->filter_expression, NULL,
749 event->userspace_probe_location,
750 &extended_len);
751 if (ret) {
752 DBG("Error computing the length of extended info message");
753 ret = -LTTNG_ERR_FATAL;
754 goto error;
755 }
756 }
757
758 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
759 *events = zmalloc(*total_size);
760 if (*events == NULL) {
761 ret = -LTTNG_ERR_FATAL;
762 goto error;
763 }
764
765 extended_at = ((void *) *events) +
766 nb_event * sizeof(struct lttng_event);
767
768 /* Kernel channels */
769 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
770 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
771 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
772 (*events)[i].enabled = event->enabled;
773 (*events)[i].filter =
774 (unsigned char) !!event->filter_expression;
775
776 switch (event->event->instrumentation) {
777 case LTTNG_KERNEL_TRACEPOINT:
778 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
779 break;
780 case LTTNG_KERNEL_KRETPROBE:
781 (*events)[i].type = LTTNG_EVENT_FUNCTION;
782 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
783 sizeof(struct lttng_kernel_kprobe));
784 break;
785 case LTTNG_KERNEL_KPROBE:
786 (*events)[i].type = LTTNG_EVENT_PROBE;
787 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
788 sizeof(struct lttng_kernel_kprobe));
789 break;
790 case LTTNG_KERNEL_UPROBE:
791 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
792 break;
793 case LTTNG_KERNEL_FUNCTION:
794 (*events)[i].type = LTTNG_EVENT_FUNCTION;
795 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
796 sizeof(struct lttng_kernel_function));
797 break;
798 case LTTNG_KERNEL_NOOP:
799 (*events)[i].type = LTTNG_EVENT_NOOP;
800 break;
801 case LTTNG_KERNEL_SYSCALL:
802 (*events)[i].type = LTTNG_EVENT_SYSCALL;
803 break;
804 case LTTNG_KERNEL_ALL:
805 /* fall-through. */
806 default:
807 assert(0);
808 break;
809 }
810 i++;
811
812 /* Append extended info */
813 ret = append_extended_info(event->filter_expression, NULL,
814 event->userspace_probe_location, &extended_at);
815 if (ret) {
816 DBG("Error appending extended info message");
817 ret = -LTTNG_ERR_FATAL;
818 goto error;
819 }
820 }
821
822 end:
823 return nb_event;
824
825 error:
826 /* Negate the error code to differentiate the size from an error */
827 return -ret;
828 }
829
830 /*
831 * Add URI so the consumer output object. Set the correct path depending on the
832 * domain adding the default trace directory.
833 */
834 static enum lttng_error_code add_uri_to_consumer(
835 const struct ltt_session *session,
836 struct consumer_output *consumer,
837 struct lttng_uri *uri, enum lttng_domain_type domain)
838 {
839 int ret;
840 enum lttng_error_code ret_code = LTTNG_OK;
841
842 assert(uri);
843
844 if (consumer == NULL) {
845 DBG("No consumer detected. Don't add URI. Stopping.");
846 ret_code = LTTNG_ERR_NO_CONSUMER;
847 goto error;
848 }
849
850 switch (domain) {
851 case LTTNG_DOMAIN_KERNEL:
852 ret = lttng_strncpy(consumer->domain_subdir,
853 DEFAULT_KERNEL_TRACE_DIR,
854 sizeof(consumer->domain_subdir));
855 break;
856 case LTTNG_DOMAIN_UST:
857 ret = lttng_strncpy(consumer->domain_subdir,
858 DEFAULT_UST_TRACE_DIR,
859 sizeof(consumer->domain_subdir));
860 break;
861 default:
862 /*
863 * This case is possible is we try to add the URI to the global
864 * tracing session consumer object which in this case there is
865 * no subdir.
866 */
867 memset(consumer->domain_subdir, 0,
868 sizeof(consumer->domain_subdir));
869 ret = 0;
870 }
871 if (ret) {
872 ERR("Failed to initialize consumer output domain subdirectory");
873 ret_code = LTTNG_ERR_FATAL;
874 goto error;
875 }
876
877 switch (uri->dtype) {
878 case LTTNG_DST_IPV4:
879 case LTTNG_DST_IPV6:
880 DBG2("Setting network URI to consumer");
881
882 if (consumer->type == CONSUMER_DST_NET) {
883 if ((uri->stype == LTTNG_STREAM_CONTROL &&
884 consumer->dst.net.control_isset) ||
885 (uri->stype == LTTNG_STREAM_DATA &&
886 consumer->dst.net.data_isset)) {
887 ret_code = LTTNG_ERR_URL_EXIST;
888 goto error;
889 }
890 } else {
891 memset(&consumer->dst, 0, sizeof(consumer->dst));
892 }
893
894 /* Set URI into consumer output object */
895 ret = consumer_set_network_uri(session, consumer, uri);
896 if (ret < 0) {
897 ret_code = -ret;
898 goto error;
899 } else if (ret == 1) {
900 /*
901 * URI was the same in the consumer so we do not append the subdir
902 * again so to not duplicate output dir.
903 */
904 ret_code = LTTNG_OK;
905 goto error;
906 }
907 break;
908 case LTTNG_DST_PATH:
909 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
910 ret_code = LTTNG_ERR_INVALID;
911 goto error;
912 }
913 DBG2("Setting trace directory path from URI to %s",
914 uri->dst.path);
915 memset(&consumer->dst, 0, sizeof(consumer->dst));
916
917 ret = lttng_strncpy(consumer->dst.session_root_path,
918 uri->dst.path,
919 sizeof(consumer->dst.session_root_path));
920 if (ret) {
921 ret_code = LTTNG_ERR_FATAL;
922 goto error;
923 }
924 consumer->type = CONSUMER_DST_LOCAL;
925 break;
926 }
927
928 ret_code = LTTNG_OK;
929 error:
930 return ret_code;
931 }
932
933 /*
934 * Init tracing by creating trace directory and sending fds kernel consumer.
935 */
936 static int init_kernel_tracing(struct ltt_kernel_session *session)
937 {
938 int ret = 0;
939 struct lttng_ht_iter iter;
940 struct consumer_socket *socket;
941
942 assert(session);
943
944 rcu_read_lock();
945
946 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
947 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
948 socket, node.node) {
949 pthread_mutex_lock(socket->lock);
950 ret = kernel_consumer_send_session(socket, session);
951 pthread_mutex_unlock(socket->lock);
952 if (ret < 0) {
953 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
954 goto error;
955 }
956 }
957 }
958
959 error:
960 rcu_read_unlock();
961 return ret;
962 }
963
964 /*
965 * Create a socket to the relayd using the URI.
966 *
967 * On success, the relayd_sock pointer is set to the created socket.
968 * Else, it remains untouched and an LTTng error code is returned.
969 */
970 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
971 struct lttcomm_relayd_sock **relayd_sock,
972 struct consumer_output *consumer)
973 {
974 int ret;
975 enum lttng_error_code status = LTTNG_OK;
976 struct lttcomm_relayd_sock *rsock;
977
978 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
979 RELAYD_VERSION_COMM_MINOR);
980 if (!rsock) {
981 status = LTTNG_ERR_FATAL;
982 goto error;
983 }
984
985 /*
986 * Connect to relayd so we can proceed with a session creation. This call
987 * can possibly block for an arbitrary amount of time to set the health
988 * state to be in poll execution.
989 */
990 health_poll_entry();
991 ret = relayd_connect(rsock);
992 health_poll_exit();
993 if (ret < 0) {
994 ERR("Unable to reach lttng-relayd");
995 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
996 goto free_sock;
997 }
998
999 /* Create socket for control stream. */
1000 if (uri->stype == LTTNG_STREAM_CONTROL) {
1001 uint64_t result_flags;
1002
1003 DBG3("Creating relayd stream socket from URI");
1004
1005 /* Check relayd version */
1006 ret = relayd_version_check(rsock);
1007 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
1008 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
1009 goto close_sock;
1010 } else if (ret < 0) {
1011 ERR("Unable to reach lttng-relayd");
1012 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1013 goto close_sock;
1014 }
1015 consumer->relay_major_version = rsock->major;
1016 consumer->relay_minor_version = rsock->minor;
1017 ret = relayd_get_configuration(rsock, 0,
1018 &result_flags);
1019 if (ret < 0) {
1020 ERR("Unable to get relayd configuration");
1021 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1022 goto close_sock;
1023 }
1024 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
1025 consumer->relay_allows_clear = true;
1026 }
1027 } else if (uri->stype == LTTNG_STREAM_DATA) {
1028 DBG3("Creating relayd data socket from URI");
1029 } else {
1030 /* Command is not valid */
1031 ERR("Relayd invalid stream type: %d", uri->stype);
1032 status = LTTNG_ERR_INVALID;
1033 goto close_sock;
1034 }
1035
1036 *relayd_sock = rsock;
1037
1038 return status;
1039
1040 close_sock:
1041 /* The returned value is not useful since we are on an error path. */
1042 (void) relayd_close(rsock);
1043 free_sock:
1044 free(rsock);
1045 error:
1046 return status;
1047 }
1048
1049 /*
1050 * Connect to the relayd using URI and send the socket to the right consumer.
1051 *
1052 * The consumer socket lock must be held by the caller.
1053 *
1054 * Returns LTTNG_OK on success or an LTTng error code on failure.
1055 */
1056 static enum lttng_error_code send_consumer_relayd_socket(
1057 unsigned int session_id,
1058 struct lttng_uri *relayd_uri,
1059 struct consumer_output *consumer,
1060 struct consumer_socket *consumer_sock,
1061 const char *session_name, const char *hostname,
1062 const char *base_path, int session_live_timer,
1063 const uint64_t *current_chunk_id,
1064 time_t session_creation_time,
1065 bool session_name_contains_creation_time)
1066 {
1067 int ret;
1068 struct lttcomm_relayd_sock *rsock = NULL;
1069 enum lttng_error_code status;
1070
1071 /* Connect to relayd and make version check if uri is the control. */
1072 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1073 if (status != LTTNG_OK) {
1074 goto relayd_comm_error;
1075 }
1076 assert(rsock);
1077
1078 /* Set the network sequence index if not set. */
1079 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1080 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1081 /*
1082 * Increment net_seq_idx because we are about to transfer the
1083 * new relayd socket to the consumer.
1084 * Assign unique key so the consumer can match streams.
1085 */
1086 consumer->net_seq_index = ++relayd_net_seq_idx;
1087 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1088 }
1089
1090 /* Send relayd socket to consumer. */
1091 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1092 relayd_uri->stype, session_id,
1093 session_name, hostname, base_path,
1094 session_live_timer, current_chunk_id,
1095 session_creation_time, session_name_contains_creation_time);
1096 if (ret < 0) {
1097 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1098 goto close_sock;
1099 }
1100
1101 /* Flag that the corresponding socket was sent. */
1102 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1103 consumer_sock->control_sock_sent = 1;
1104 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1105 consumer_sock->data_sock_sent = 1;
1106 }
1107
1108 /*
1109 * Close socket which was dup on the consumer side. The session daemon does
1110 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1111 */
1112
1113 close_sock:
1114 if (status != LTTNG_OK) {
1115 /*
1116 * The consumer output for this session should not be used anymore
1117 * since the relayd connection failed thus making any tracing or/and
1118 * streaming not usable.
1119 */
1120 consumer->enabled = 0;
1121 }
1122 (void) relayd_close(rsock);
1123 free(rsock);
1124
1125 relayd_comm_error:
1126 return status;
1127 }
1128
1129 /*
1130 * Send both relayd sockets to a specific consumer and domain. This is a
1131 * helper function to facilitate sending the information to the consumer for a
1132 * session.
1133 *
1134 * The consumer socket lock must be held by the caller.
1135 *
1136 * Returns LTTNG_OK, or an LTTng error code on failure.
1137 */
1138 static enum lttng_error_code send_consumer_relayd_sockets(
1139 enum lttng_domain_type domain,
1140 unsigned int session_id, struct consumer_output *consumer,
1141 struct consumer_socket *sock, const char *session_name,
1142 const char *hostname, const char *base_path, int session_live_timer,
1143 const uint64_t *current_chunk_id, time_t session_creation_time,
1144 bool session_name_contains_creation_time)
1145 {
1146 enum lttng_error_code status = LTTNG_OK;
1147
1148 assert(consumer);
1149 assert(sock);
1150
1151 /* Sending control relayd socket. */
1152 if (!sock->control_sock_sent) {
1153 status = send_consumer_relayd_socket(session_id,
1154 &consumer->dst.net.control, consumer, sock,
1155 session_name, hostname, base_path, session_live_timer,
1156 current_chunk_id, session_creation_time,
1157 session_name_contains_creation_time);
1158 if (status != LTTNG_OK) {
1159 goto error;
1160 }
1161 }
1162
1163 /* Sending data relayd socket. */
1164 if (!sock->data_sock_sent) {
1165 status = send_consumer_relayd_socket(session_id,
1166 &consumer->dst.net.data, consumer, sock,
1167 session_name, hostname, base_path, session_live_timer,
1168 current_chunk_id, session_creation_time,
1169 session_name_contains_creation_time);
1170 if (status != LTTNG_OK) {
1171 goto error;
1172 }
1173 }
1174
1175 error:
1176 return status;
1177 }
1178
1179 /*
1180 * Setup relayd connections for a tracing session. First creates the socket to
1181 * the relayd and send them to the right domain consumer. Consumer type MUST be
1182 * network.
1183 */
1184 int cmd_setup_relayd(struct ltt_session *session)
1185 {
1186 int ret = LTTNG_OK;
1187 struct ltt_ust_session *usess;
1188 struct ltt_kernel_session *ksess;
1189 struct consumer_socket *socket;
1190 struct lttng_ht_iter iter;
1191 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1192
1193 assert(session);
1194
1195 usess = session->ust_session;
1196 ksess = session->kernel_session;
1197
1198 DBG("Setting relayd for session %s", session->name);
1199
1200 rcu_read_lock();
1201 if (session->current_trace_chunk) {
1202 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1203 session->current_trace_chunk, &current_chunk_id.value);
1204
1205 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1206 current_chunk_id.is_set = true;
1207 } else {
1208 ERR("Failed to get current trace chunk id");
1209 ret = LTTNG_ERR_UNK;
1210 goto error;
1211 }
1212 }
1213
1214 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1215 && usess->consumer->enabled) {
1216 /* For each consumer socket, send relayd sockets */
1217 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1218 socket, node.node) {
1219 pthread_mutex_lock(socket->lock);
1220 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1221 usess->consumer, socket,
1222 session->name, session->hostname,
1223 session->base_path,
1224 session->live_timer,
1225 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1226 session->creation_time,
1227 session->name_contains_creation_time);
1228 pthread_mutex_unlock(socket->lock);
1229 if (ret != LTTNG_OK) {
1230 goto error;
1231 }
1232 /* Session is now ready for network streaming. */
1233 session->net_handle = 1;
1234 }
1235 session->consumer->relay_major_version =
1236 usess->consumer->relay_major_version;
1237 session->consumer->relay_minor_version =
1238 usess->consumer->relay_minor_version;
1239 session->consumer->relay_allows_clear =
1240 usess->consumer->relay_allows_clear;
1241 }
1242
1243 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1244 && ksess->consumer->enabled) {
1245 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1246 socket, node.node) {
1247 pthread_mutex_lock(socket->lock);
1248 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1249 ksess->consumer, socket,
1250 session->name, session->hostname,
1251 session->base_path,
1252 session->live_timer,
1253 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1254 session->creation_time,
1255 session->name_contains_creation_time);
1256 pthread_mutex_unlock(socket->lock);
1257 if (ret != LTTNG_OK) {
1258 goto error;
1259 }
1260 /* Session is now ready for network streaming. */
1261 session->net_handle = 1;
1262 }
1263 session->consumer->relay_major_version =
1264 ksess->consumer->relay_major_version;
1265 session->consumer->relay_minor_version =
1266 ksess->consumer->relay_minor_version;
1267 session->consumer->relay_allows_clear =
1268 ksess->consumer->relay_allows_clear;
1269 }
1270
1271 error:
1272 rcu_read_unlock();
1273 return ret;
1274 }
1275
1276 /*
1277 * Start a kernel session by opening all necessary streams.
1278 */
1279 int start_kernel_session(struct ltt_kernel_session *ksess)
1280 {
1281 int ret;
1282 struct ltt_kernel_channel *kchan;
1283
1284 /* Open kernel metadata */
1285 if (ksess->metadata == NULL && ksess->output_traces) {
1286 ret = kernel_open_metadata(ksess);
1287 if (ret < 0) {
1288 ret = LTTNG_ERR_KERN_META_FAIL;
1289 goto error;
1290 }
1291 }
1292
1293 /* Open kernel metadata stream */
1294 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1295 ret = kernel_open_metadata_stream(ksess);
1296 if (ret < 0) {
1297 ERR("Kernel create metadata stream failed");
1298 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1299 goto error;
1300 }
1301 }
1302
1303 /* For each channel */
1304 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1305 if (kchan->stream_count == 0) {
1306 ret = kernel_open_channel_stream(kchan);
1307 if (ret < 0) {
1308 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1309 goto error;
1310 }
1311 /* Update the stream global counter */
1312 ksess->stream_count_global += ret;
1313 }
1314 }
1315
1316 /* Setup kernel consumer socket and send fds to it */
1317 ret = init_kernel_tracing(ksess);
1318 if (ret != 0) {
1319 ret = LTTNG_ERR_KERN_START_FAIL;
1320 goto error;
1321 }
1322
1323 /* This start the kernel tracing */
1324 ret = kernel_start_session(ksess);
1325 if (ret < 0) {
1326 ret = LTTNG_ERR_KERN_START_FAIL;
1327 goto error;
1328 }
1329
1330 /* Quiescent wait after starting trace */
1331 kernel_wait_quiescent();
1332
1333 ksess->active = 1;
1334
1335 ret = LTTNG_OK;
1336
1337 error:
1338 return ret;
1339 }
1340
1341 int stop_kernel_session(struct ltt_kernel_session *ksess)
1342 {
1343 struct ltt_kernel_channel *kchan;
1344 bool error_occurred = false;
1345 int ret;
1346
1347 if (!ksess || !ksess->active) {
1348 return LTTNG_OK;
1349 }
1350 DBG("Stopping kernel tracing");
1351
1352 ret = kernel_stop_session(ksess);
1353 if (ret < 0) {
1354 ret = LTTNG_ERR_KERN_STOP_FAIL;
1355 goto error;
1356 }
1357
1358 kernel_wait_quiescent();
1359
1360 /* Flush metadata after stopping (if exists) */
1361 if (ksess->metadata_stream_fd >= 0) {
1362 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1363 if (ret < 0) {
1364 ERR("Kernel metadata flush failed");
1365 error_occurred = true;
1366 }
1367 }
1368
1369 /* Flush all buffers after stopping */
1370 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1371 ret = kernel_flush_buffer(kchan);
1372 if (ret < 0) {
1373 ERR("Kernel flush buffer error");
1374 error_occurred = true;
1375 }
1376 }
1377
1378 ksess->active = 0;
1379 if (error_occurred) {
1380 ret = LTTNG_ERR_UNK;
1381 } else {
1382 ret = LTTNG_OK;
1383 }
1384 error:
1385 return ret;
1386 }
1387
1388 /*
1389 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1390 */
1391 int cmd_disable_channel(struct ltt_session *session,
1392 enum lttng_domain_type domain, char *channel_name)
1393 {
1394 int ret;
1395 struct ltt_ust_session *usess;
1396
1397 usess = session->ust_session;
1398
1399 rcu_read_lock();
1400
1401 switch (domain) {
1402 case LTTNG_DOMAIN_KERNEL:
1403 {
1404 ret = channel_kernel_disable(session->kernel_session,
1405 channel_name);
1406 if (ret != LTTNG_OK) {
1407 goto error;
1408 }
1409
1410 kernel_wait_quiescent();
1411 break;
1412 }
1413 case LTTNG_DOMAIN_UST:
1414 {
1415 struct ltt_ust_channel *uchan;
1416 struct lttng_ht *chan_ht;
1417
1418 chan_ht = usess->domain_global.channels;
1419
1420 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1421 if (uchan == NULL) {
1422 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1423 goto error;
1424 }
1425
1426 ret = channel_ust_disable(usess, uchan);
1427 if (ret != LTTNG_OK) {
1428 goto error;
1429 }
1430 break;
1431 }
1432 default:
1433 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1434 goto error;
1435 }
1436
1437 ret = LTTNG_OK;
1438
1439 error:
1440 rcu_read_unlock();
1441 return ret;
1442 }
1443
1444 /*
1445 * Command LTTNG_TRACK_ID processed by the client thread.
1446 *
1447 * Called with session lock held.
1448 */
1449 int cmd_track_id(struct ltt_session *session,
1450 enum lttng_tracker_type tracker_type,
1451 enum lttng_domain_type domain,
1452 const struct lttng_tracker_id *id)
1453 {
1454 int ret;
1455
1456 rcu_read_lock();
1457
1458 switch (domain) {
1459 case LTTNG_DOMAIN_KERNEL:
1460 {
1461 struct ltt_kernel_session *ksess;
1462
1463 ksess = session->kernel_session;
1464
1465 ret = kernel_track_id(tracker_type, ksess, id);
1466 if (ret != LTTNG_OK) {
1467 goto error;
1468 }
1469
1470 kernel_wait_quiescent();
1471 break;
1472 }
1473 case LTTNG_DOMAIN_UST:
1474 {
1475 struct ltt_ust_session *usess;
1476
1477 usess = session->ust_session;
1478
1479 ret = trace_ust_track_id(tracker_type, usess, id);
1480 if (ret != LTTNG_OK) {
1481 goto error;
1482 }
1483 break;
1484 }
1485 default:
1486 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1487 goto error;
1488 }
1489
1490 ret = LTTNG_OK;
1491
1492 error:
1493 rcu_read_unlock();
1494 return ret;
1495 }
1496
1497 /*
1498 * Command LTTNG_UNTRACK_ID processed by the client thread.
1499 *
1500 * Called with session lock held.
1501 */
1502 int cmd_untrack_id(struct ltt_session *session,
1503 enum lttng_tracker_type tracker_type,
1504 enum lttng_domain_type domain,
1505 const struct lttng_tracker_id *id)
1506 {
1507 int ret;
1508
1509 rcu_read_lock();
1510
1511 switch (domain) {
1512 case LTTNG_DOMAIN_KERNEL:
1513 {
1514 struct ltt_kernel_session *ksess;
1515
1516 ksess = session->kernel_session;
1517
1518 ret = kernel_untrack_id(tracker_type, ksess, id);
1519 if (ret != LTTNG_OK) {
1520 goto error;
1521 }
1522
1523 kernel_wait_quiescent();
1524 break;
1525 }
1526 case LTTNG_DOMAIN_UST:
1527 {
1528 struct ltt_ust_session *usess;
1529
1530 usess = session->ust_session;
1531
1532 ret = trace_ust_untrack_id(tracker_type, usess, id);
1533 if (ret != LTTNG_OK) {
1534 goto error;
1535 }
1536 break;
1537 }
1538 default:
1539 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1540 goto error;
1541 }
1542
1543 ret = LTTNG_OK;
1544
1545 error:
1546 rcu_read_unlock();
1547 return ret;
1548 }
1549
1550 /*
1551 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1552 *
1553 * The wpipe arguments is used as a notifier for the kernel thread.
1554 */
1555 int cmd_enable_channel(struct ltt_session *session,
1556 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1557 {
1558 int ret;
1559 struct ltt_ust_session *usess = session->ust_session;
1560 struct lttng_ht *chan_ht;
1561 size_t len;
1562 struct lttng_channel attr;
1563
1564 assert(session);
1565 assert(_attr);
1566 assert(domain);
1567
1568 attr = *_attr;
1569 len = lttng_strnlen(attr.name, sizeof(attr.name));
1570
1571 /* Validate channel name */
1572 if (attr.name[0] == '.' ||
1573 memchr(attr.name, '/', len) != NULL) {
1574 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1575 goto end;
1576 }
1577
1578 DBG("Enabling channel %s for session %s", attr.name, session->name);
1579
1580 rcu_read_lock();
1581
1582 /*
1583 * Don't try to enable a channel if the session has been started at
1584 * some point in time before. The tracer does not allow it.
1585 */
1586 if (session->has_been_started) {
1587 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1588 goto error;
1589 }
1590
1591 /*
1592 * If the session is a live session, remove the switch timer, the
1593 * live timer does the same thing but sends also synchronisation
1594 * beacons for inactive streams.
1595 */
1596 if (session->live_timer > 0) {
1597 attr.attr.live_timer_interval = session->live_timer;
1598 attr.attr.switch_timer_interval = 0;
1599 }
1600
1601 /* Check for feature support */
1602 switch (domain->type) {
1603 case LTTNG_DOMAIN_KERNEL:
1604 {
1605 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1606 /* Sampling position of buffer is not supported */
1607 WARN("Kernel tracer does not support buffer monitoring. "
1608 "Setting the monitor interval timer to 0 "
1609 "(disabled) for channel '%s' of session '%s'",
1610 attr.name, session->name);
1611 lttng_channel_set_monitor_timer_interval(&attr, 0);
1612 }
1613 break;
1614 }
1615 case LTTNG_DOMAIN_UST:
1616 break;
1617 case LTTNG_DOMAIN_JUL:
1618 case LTTNG_DOMAIN_LOG4J:
1619 case LTTNG_DOMAIN_PYTHON:
1620 if (!agent_tracing_is_enabled()) {
1621 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1622 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1623 goto error;
1624 }
1625 break;
1626 default:
1627 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1628 goto error;
1629 }
1630
1631 switch (domain->type) {
1632 case LTTNG_DOMAIN_KERNEL:
1633 {
1634 struct ltt_kernel_channel *kchan;
1635
1636 kchan = trace_kernel_get_channel_by_name(attr.name,
1637 session->kernel_session);
1638 if (kchan == NULL) {
1639 if (session->snapshot.nb_output > 0 ||
1640 session->snapshot_mode) {
1641 /* Enforce mmap output for snapshot sessions. */
1642 attr.attr.output = LTTNG_EVENT_MMAP;
1643 }
1644 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1645 if (attr.name[0] != '\0') {
1646 session->kernel_session->has_non_default_channel = 1;
1647 }
1648 } else {
1649 ret = channel_kernel_enable(session->kernel_session, kchan);
1650 }
1651
1652 if (ret != LTTNG_OK) {
1653 goto error;
1654 }
1655
1656 kernel_wait_quiescent();
1657 break;
1658 }
1659 case LTTNG_DOMAIN_UST:
1660 case LTTNG_DOMAIN_JUL:
1661 case LTTNG_DOMAIN_LOG4J:
1662 case LTTNG_DOMAIN_PYTHON:
1663 {
1664 struct ltt_ust_channel *uchan;
1665
1666 /*
1667 * FIXME
1668 *
1669 * Current agent implementation limitations force us to allow
1670 * only one channel at once in "agent" subdomains. Each
1671 * subdomain has a default channel name which must be strictly
1672 * adhered to.
1673 */
1674 if (domain->type == LTTNG_DOMAIN_JUL) {
1675 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1676 LTTNG_SYMBOL_NAME_LEN)) {
1677 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1678 goto error;
1679 }
1680 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1681 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1682 LTTNG_SYMBOL_NAME_LEN)) {
1683 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1684 goto error;
1685 }
1686 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1687 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1688 LTTNG_SYMBOL_NAME_LEN)) {
1689 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1690 goto error;
1691 }
1692 }
1693
1694 chan_ht = usess->domain_global.channels;
1695
1696 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1697 if (uchan == NULL) {
1698 ret = channel_ust_create(usess, &attr, domain->buf_type);
1699 if (attr.name[0] != '\0') {
1700 usess->has_non_default_channel = 1;
1701 }
1702 } else {
1703 ret = channel_ust_enable(usess, uchan);
1704 }
1705 break;
1706 }
1707 default:
1708 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1709 goto error;
1710 }
1711
1712 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1713 session->has_non_mmap_channel = true;
1714 }
1715 error:
1716 rcu_read_unlock();
1717 end:
1718 return ret;
1719 }
1720
1721 /*
1722 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1723 */
1724 int cmd_disable_event(struct ltt_session *session,
1725 enum lttng_domain_type domain, const char *channel_name,
1726 const struct lttng_event *event)
1727 {
1728 int ret;
1729 const char *event_name;
1730
1731 DBG("Disable event command for event \'%s\'", event->name);
1732
1733 event_name = event->name;
1734
1735 /* Error out on unhandled search criteria */
1736 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1737 || event->pid || event->filter || event->exclusion) {
1738 ret = LTTNG_ERR_UNK;
1739 goto error;
1740 }
1741
1742 rcu_read_lock();
1743
1744 switch (domain) {
1745 case LTTNG_DOMAIN_KERNEL:
1746 {
1747 struct ltt_kernel_channel *kchan;
1748 struct ltt_kernel_session *ksess;
1749
1750 ksess = session->kernel_session;
1751
1752 /*
1753 * If a non-default channel has been created in the
1754 * session, explicitely require that -c chan_name needs
1755 * to be provided.
1756 */
1757 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1758 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1759 goto error_unlock;
1760 }
1761
1762 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1763 if (kchan == NULL) {
1764 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1765 goto error_unlock;
1766 }
1767
1768 switch (event->type) {
1769 case LTTNG_EVENT_ALL:
1770 case LTTNG_EVENT_TRACEPOINT:
1771 case LTTNG_EVENT_SYSCALL:
1772 case LTTNG_EVENT_PROBE:
1773 case LTTNG_EVENT_FUNCTION:
1774 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1775 if (event_name[0] == '\0') {
1776 ret = event_kernel_disable_event(kchan,
1777 NULL, event->type);
1778 } else {
1779 ret = event_kernel_disable_event(kchan,
1780 event_name, event->type);
1781 }
1782 if (ret != LTTNG_OK) {
1783 goto error_unlock;
1784 }
1785 break;
1786 default:
1787 ret = LTTNG_ERR_UNK;
1788 goto error_unlock;
1789 }
1790
1791 kernel_wait_quiescent();
1792 break;
1793 }
1794 case LTTNG_DOMAIN_UST:
1795 {
1796 struct ltt_ust_channel *uchan;
1797 struct ltt_ust_session *usess;
1798
1799 usess = session->ust_session;
1800
1801 if (validate_ust_event_name(event_name)) {
1802 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1803 goto error_unlock;
1804 }
1805
1806 /*
1807 * If a non-default channel has been created in the
1808 * session, explicitly require that -c chan_name needs
1809 * to be provided.
1810 */
1811 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1812 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1813 goto error_unlock;
1814 }
1815
1816 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1817 channel_name);
1818 if (uchan == NULL) {
1819 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1820 goto error_unlock;
1821 }
1822
1823 switch (event->type) {
1824 case LTTNG_EVENT_ALL:
1825 /*
1826 * An empty event name means that everything
1827 * should be disabled.
1828 */
1829 if (event->name[0] == '\0') {
1830 ret = event_ust_disable_all_tracepoints(usess, uchan);
1831 } else {
1832 ret = event_ust_disable_tracepoint(usess, uchan,
1833 event_name);
1834 }
1835 if (ret != LTTNG_OK) {
1836 goto error_unlock;
1837 }
1838 break;
1839 default:
1840 ret = LTTNG_ERR_UNK;
1841 goto error_unlock;
1842 }
1843
1844 DBG3("Disable UST event %s in channel %s completed", event_name,
1845 channel_name);
1846 break;
1847 }
1848 case LTTNG_DOMAIN_LOG4J:
1849 case LTTNG_DOMAIN_JUL:
1850 case LTTNG_DOMAIN_PYTHON:
1851 {
1852 struct agent *agt;
1853 struct ltt_ust_session *usess = session->ust_session;
1854
1855 assert(usess);
1856
1857 switch (event->type) {
1858 case LTTNG_EVENT_ALL:
1859 break;
1860 default:
1861 ret = LTTNG_ERR_UNK;
1862 goto error_unlock;
1863 }
1864
1865 agt = trace_ust_find_agent(usess, domain);
1866 if (!agt) {
1867 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1868 goto error_unlock;
1869 }
1870 /*
1871 * An empty event name means that everything
1872 * should be disabled.
1873 */
1874 if (event->name[0] == '\0') {
1875 ret = event_agent_disable_all(usess, agt);
1876 } else {
1877 ret = event_agent_disable(usess, agt, event_name);
1878 }
1879 if (ret != LTTNG_OK) {
1880 goto error_unlock;
1881 }
1882
1883 break;
1884 }
1885 default:
1886 ret = LTTNG_ERR_UND;
1887 goto error_unlock;
1888 }
1889
1890 ret = LTTNG_OK;
1891
1892 error_unlock:
1893 rcu_read_unlock();
1894 error:
1895 return ret;
1896 }
1897
1898 /*
1899 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1900 */
1901 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1902 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1903 {
1904 int ret, chan_kern_created = 0, chan_ust_created = 0;
1905 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1906
1907 /*
1908 * Don't try to add a context if the session has been started at
1909 * some point in time before. The tracer does not allow it and would
1910 * result in a corrupted trace.
1911 */
1912 if (session->has_been_started) {
1913 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1914 goto end;
1915 }
1916
1917 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1918 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1919 app_ctx_name = ctx->u.app_ctx.ctx_name;
1920 }
1921
1922 switch (domain) {
1923 case LTTNG_DOMAIN_KERNEL:
1924 assert(session->kernel_session);
1925
1926 if (session->kernel_session->channel_count == 0) {
1927 /* Create default channel */
1928 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1929 if (ret != LTTNG_OK) {
1930 goto error;
1931 }
1932 chan_kern_created = 1;
1933 }
1934 /* Add kernel context to kernel tracer */
1935 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1936 if (ret != LTTNG_OK) {
1937 goto error;
1938 }
1939 break;
1940 case LTTNG_DOMAIN_JUL:
1941 case LTTNG_DOMAIN_LOG4J:
1942 {
1943 /*
1944 * Validate channel name.
1945 * If no channel name is given and the domain is JUL or LOG4J,
1946 * set it to the appropriate domain-specific channel name. If
1947 * a name is provided but does not match the expexted channel
1948 * name, return an error.
1949 */
1950 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1951 strcmp(channel_name,
1952 DEFAULT_JUL_CHANNEL_NAME)) {
1953 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1954 goto error;
1955 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1956 strcmp(channel_name,
1957 DEFAULT_LOG4J_CHANNEL_NAME)) {
1958 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1959 goto error;
1960 }
1961 /* break is _not_ missing here. */
1962 }
1963 case LTTNG_DOMAIN_UST:
1964 {
1965 struct ltt_ust_session *usess = session->ust_session;
1966 unsigned int chan_count;
1967
1968 assert(usess);
1969
1970 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1971 if (chan_count == 0) {
1972 struct lttng_channel *attr;
1973 /* Create default channel */
1974 attr = channel_new_default_attr(domain, usess->buffer_type);
1975 if (attr == NULL) {
1976 ret = LTTNG_ERR_FATAL;
1977 goto error;
1978 }
1979
1980 ret = channel_ust_create(usess, attr, usess->buffer_type);
1981 if (ret != LTTNG_OK) {
1982 free(attr);
1983 goto error;
1984 }
1985 channel_attr_destroy(attr);
1986 chan_ust_created = 1;
1987 }
1988
1989 ret = context_ust_add(usess, domain, ctx, channel_name);
1990 free(app_ctx_provider_name);
1991 free(app_ctx_name);
1992 app_ctx_name = NULL;
1993 app_ctx_provider_name = NULL;
1994 if (ret != LTTNG_OK) {
1995 goto error;
1996 }
1997 break;
1998 }
1999 default:
2000 ret = LTTNG_ERR_UND;
2001 goto error;
2002 }
2003
2004 ret = LTTNG_OK;
2005 goto end;
2006
2007 error:
2008 if (chan_kern_created) {
2009 struct ltt_kernel_channel *kchan =
2010 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
2011 session->kernel_session);
2012 /* Created previously, this should NOT fail. */
2013 assert(kchan);
2014 kernel_destroy_channel(kchan);
2015 }
2016
2017 if (chan_ust_created) {
2018 struct ltt_ust_channel *uchan =
2019 trace_ust_find_channel_by_name(
2020 session->ust_session->domain_global.channels,
2021 DEFAULT_CHANNEL_NAME);
2022 /* Created previously, this should NOT fail. */
2023 assert(uchan);
2024 /* Remove from the channel list of the session. */
2025 trace_ust_delete_channel(session->ust_session->domain_global.channels,
2026 uchan);
2027 trace_ust_destroy_channel(uchan);
2028 }
2029 end:
2030 free(app_ctx_provider_name);
2031 free(app_ctx_name);
2032 return ret;
2033 }
2034
2035 static inline bool name_starts_with(const char *name, const char *prefix)
2036 {
2037 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
2038
2039 return !strncmp(name, prefix, max_cmp_len);
2040 }
2041
2042 /* Perform userspace-specific event name validation */
2043 static int validate_ust_event_name(const char *name)
2044 {
2045 int ret = 0;
2046
2047 if (!name) {
2048 ret = -1;
2049 goto end;
2050 }
2051
2052 /*
2053 * Check name against all internal UST event component namespaces used
2054 * by the agents.
2055 */
2056 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2057 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2058 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2059 ret = -1;
2060 }
2061
2062 end:
2063 return ret;
2064 }
2065
2066 /*
2067 * Internal version of cmd_enable_event() with a supplemental
2068 * "internal_event" flag which is used to enable internal events which should
2069 * be hidden from clients. Such events are used in the agent implementation to
2070 * enable the events through which all "agent" events are funeled.
2071 */
2072 static int _cmd_enable_event(struct ltt_session *session,
2073 const struct lttng_domain *domain,
2074 char *channel_name, struct lttng_event *event,
2075 char *filter_expression,
2076 struct lttng_filter_bytecode *filter,
2077 struct lttng_event_exclusion *exclusion,
2078 int wpipe, bool internal_event)
2079 {
2080 int ret = 0, channel_created = 0;
2081 struct lttng_channel *attr = NULL;
2082
2083 assert(session);
2084 assert(event);
2085 assert(channel_name);
2086
2087 /* If we have a filter, we must have its filter expression */
2088 assert(!(!!filter_expression ^ !!filter));
2089
2090 /* Normalize event name as a globbing pattern */
2091 strutils_normalize_star_glob_pattern(event->name);
2092
2093 /* Normalize exclusion names as globbing patterns */
2094 if (exclusion) {
2095 size_t i;
2096
2097 for (i = 0; i < exclusion->count; i++) {
2098 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2099
2100 strutils_normalize_star_glob_pattern(name);
2101 }
2102 }
2103
2104 DBG("Enable event command for event \'%s\'", event->name);
2105
2106 rcu_read_lock();
2107
2108 switch (domain->type) {
2109 case LTTNG_DOMAIN_KERNEL:
2110 {
2111 struct ltt_kernel_channel *kchan;
2112
2113 /*
2114 * If a non-default channel has been created in the
2115 * session, explicitely require that -c chan_name needs
2116 * to be provided.
2117 */
2118 if (session->kernel_session->has_non_default_channel
2119 && channel_name[0] == '\0') {
2120 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2121 goto error;
2122 }
2123
2124 kchan = trace_kernel_get_channel_by_name(channel_name,
2125 session->kernel_session);
2126 if (kchan == NULL) {
2127 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2128 LTTNG_BUFFER_GLOBAL);
2129 if (attr == NULL) {
2130 ret = LTTNG_ERR_FATAL;
2131 goto error;
2132 }
2133 if (lttng_strncpy(attr->name, channel_name,
2134 sizeof(attr->name))) {
2135 ret = LTTNG_ERR_INVALID;
2136 goto error;
2137 }
2138
2139 ret = cmd_enable_channel(session, domain, attr, wpipe);
2140 if (ret != LTTNG_OK) {
2141 goto error;
2142 }
2143 channel_created = 1;
2144 }
2145
2146 /* Get the newly created kernel channel pointer */
2147 kchan = trace_kernel_get_channel_by_name(channel_name,
2148 session->kernel_session);
2149 if (kchan == NULL) {
2150 /* This sould not happen... */
2151 ret = LTTNG_ERR_FATAL;
2152 goto error;
2153 }
2154
2155 switch (event->type) {
2156 case LTTNG_EVENT_ALL:
2157 {
2158 char *filter_expression_a = NULL;
2159 struct lttng_filter_bytecode *filter_a = NULL;
2160
2161 /*
2162 * We need to duplicate filter_expression and filter,
2163 * because ownership is passed to first enable
2164 * event.
2165 */
2166 if (filter_expression) {
2167 filter_expression_a = strdup(filter_expression);
2168 if (!filter_expression_a) {
2169 ret = LTTNG_ERR_FATAL;
2170 goto error;
2171 }
2172 }
2173 if (filter) {
2174 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2175 if (!filter_a) {
2176 free(filter_expression_a);
2177 ret = LTTNG_ERR_FATAL;
2178 goto error;
2179 }
2180 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2181 }
2182 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2183 ret = event_kernel_enable_event(kchan, event,
2184 filter_expression, filter);
2185 /* We have passed ownership */
2186 filter_expression = NULL;
2187 filter = NULL;
2188 if (ret != LTTNG_OK) {
2189 if (channel_created) {
2190 /* Let's not leak a useless channel. */
2191 kernel_destroy_channel(kchan);
2192 }
2193 free(filter_expression_a);
2194 free(filter_a);
2195 goto error;
2196 }
2197 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2198 ret = event_kernel_enable_event(kchan, event,
2199 filter_expression_a, filter_a);
2200 /* We have passed ownership */
2201 filter_expression_a = NULL;
2202 filter_a = NULL;
2203 if (ret != LTTNG_OK) {
2204 goto error;
2205 }
2206 break;
2207 }
2208 case LTTNG_EVENT_PROBE:
2209 case LTTNG_EVENT_USERSPACE_PROBE:
2210 case LTTNG_EVENT_FUNCTION:
2211 case LTTNG_EVENT_FUNCTION_ENTRY:
2212 case LTTNG_EVENT_TRACEPOINT:
2213 ret = event_kernel_enable_event(kchan, event,
2214 filter_expression, filter);
2215 /* We have passed ownership */
2216 filter_expression = NULL;
2217 filter = NULL;
2218 if (ret != LTTNG_OK) {
2219 if (channel_created) {
2220 /* Let's not leak a useless channel. */
2221 kernel_destroy_channel(kchan);
2222 }
2223 goto error;
2224 }
2225 break;
2226 case LTTNG_EVENT_SYSCALL:
2227 ret = event_kernel_enable_event(kchan, event,
2228 filter_expression, filter);
2229 /* We have passed ownership */
2230 filter_expression = NULL;
2231 filter = NULL;
2232 if (ret != LTTNG_OK) {
2233 goto error;
2234 }
2235 break;
2236 default:
2237 ret = LTTNG_ERR_UNK;
2238 goto error;
2239 }
2240
2241 kernel_wait_quiescent();
2242 break;
2243 }
2244 case LTTNG_DOMAIN_UST:
2245 {
2246 struct ltt_ust_channel *uchan;
2247 struct ltt_ust_session *usess = session->ust_session;
2248
2249 assert(usess);
2250
2251 /*
2252 * If a non-default channel has been created in the
2253 * session, explicitely require that -c chan_name needs
2254 * to be provided.
2255 */
2256 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2257 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2258 goto error;
2259 }
2260
2261 /* Get channel from global UST domain */
2262 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2263 channel_name);
2264 if (uchan == NULL) {
2265 /* Create default channel */
2266 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2267 usess->buffer_type);
2268 if (attr == NULL) {
2269 ret = LTTNG_ERR_FATAL;
2270 goto error;
2271 }
2272 if (lttng_strncpy(attr->name, channel_name,
2273 sizeof(attr->name))) {
2274 ret = LTTNG_ERR_INVALID;
2275 goto error;
2276 }
2277
2278 ret = cmd_enable_channel(session, domain, attr, wpipe);
2279 if (ret != LTTNG_OK) {
2280 goto error;
2281 }
2282
2283 /* Get the newly created channel reference back */
2284 uchan = trace_ust_find_channel_by_name(
2285 usess->domain_global.channels, channel_name);
2286 assert(uchan);
2287 }
2288
2289 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2290 /*
2291 * Don't allow users to add UST events to channels which
2292 * are assigned to a userspace subdomain (JUL, Log4J,
2293 * Python, etc.).
2294 */
2295 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2296 goto error;
2297 }
2298
2299 if (!internal_event) {
2300 /*
2301 * Ensure the event name is not reserved for internal
2302 * use.
2303 */
2304 ret = validate_ust_event_name(event->name);
2305 if (ret) {
2306 WARN("Userspace event name %s failed validation.",
2307 event->name);
2308 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2309 goto error;
2310 }
2311 }
2312
2313 /* At this point, the session and channel exist on the tracer */
2314 ret = event_ust_enable_tracepoint(usess, uchan, event,
2315 filter_expression, filter, exclusion,
2316 internal_event);
2317 /* We have passed ownership */
2318 filter_expression = NULL;
2319 filter = NULL;
2320 exclusion = NULL;
2321 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2322 goto already_enabled;
2323 } else if (ret != LTTNG_OK) {
2324 goto error;
2325 }
2326 break;
2327 }
2328 case LTTNG_DOMAIN_LOG4J:
2329 case LTTNG_DOMAIN_JUL:
2330 case LTTNG_DOMAIN_PYTHON:
2331 {
2332 const char *default_event_name, *default_chan_name;
2333 struct agent *agt;
2334 struct lttng_event uevent;
2335 struct lttng_domain tmp_dom;
2336 struct ltt_ust_session *usess = session->ust_session;
2337
2338 assert(usess);
2339
2340 if (!agent_tracing_is_enabled()) {
2341 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2342 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2343 goto error;
2344 }
2345
2346 agt = trace_ust_find_agent(usess, domain->type);
2347 if (!agt) {
2348 agt = agent_create(domain->type);
2349 if (!agt) {
2350 ret = LTTNG_ERR_NOMEM;
2351 goto error;
2352 }
2353 agent_add(agt, usess->agents);
2354 }
2355
2356 /* Create the default tracepoint. */
2357 memset(&uevent, 0, sizeof(uevent));
2358 uevent.type = LTTNG_EVENT_TRACEPOINT;
2359 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2360 default_event_name = event_get_default_agent_ust_name(
2361 domain->type);
2362 if (!default_event_name) {
2363 ret = LTTNG_ERR_FATAL;
2364 goto error;
2365 }
2366 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2367 uevent.name[sizeof(uevent.name) - 1] = '\0';
2368
2369 /*
2370 * The domain type is changed because we are about to enable the
2371 * default channel and event for the JUL domain that are hardcoded.
2372 * This happens in the UST domain.
2373 */
2374 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2375 tmp_dom.type = LTTNG_DOMAIN_UST;
2376
2377 switch (domain->type) {
2378 case LTTNG_DOMAIN_LOG4J:
2379 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2380 break;
2381 case LTTNG_DOMAIN_JUL:
2382 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2383 break;
2384 case LTTNG_DOMAIN_PYTHON:
2385 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2386 break;
2387 default:
2388 /* The switch/case we are in makes this impossible */
2389 assert(0);
2390 }
2391
2392 {
2393 char *filter_expression_copy = NULL;
2394 struct lttng_filter_bytecode *filter_copy = NULL;
2395
2396 if (filter) {
2397 const size_t filter_size = sizeof(
2398 struct lttng_filter_bytecode)
2399 + filter->len;
2400
2401 filter_copy = zmalloc(filter_size);
2402 if (!filter_copy) {
2403 ret = LTTNG_ERR_NOMEM;
2404 goto error;
2405 }
2406 memcpy(filter_copy, filter, filter_size);
2407
2408 filter_expression_copy =
2409 strdup(filter_expression);
2410 if (!filter_expression) {
2411 ret = LTTNG_ERR_NOMEM;
2412 }
2413
2414 if (!filter_expression_copy || !filter_copy) {
2415 free(filter_expression_copy);
2416 free(filter_copy);
2417 goto error;
2418 }
2419 }
2420
2421 ret = cmd_enable_event_internal(session, &tmp_dom,
2422 (char *) default_chan_name,
2423 &uevent, filter_expression_copy,
2424 filter_copy, NULL, wpipe);
2425 }
2426
2427 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2428 goto already_enabled;
2429 } else if (ret != LTTNG_OK) {
2430 goto error;
2431 }
2432
2433 /* The wild card * means that everything should be enabled. */
2434 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2435 ret = event_agent_enable_all(usess, agt, event, filter,
2436 filter_expression);
2437 } else {
2438 ret = event_agent_enable(usess, agt, event, filter,
2439 filter_expression);
2440 }
2441 filter = NULL;
2442 filter_expression = NULL;
2443 if (ret != LTTNG_OK) {
2444 goto error;
2445 }
2446
2447 break;
2448 }
2449 default:
2450 ret = LTTNG_ERR_UND;
2451 goto error;
2452 }
2453
2454 ret = LTTNG_OK;
2455
2456 already_enabled:
2457 error:
2458 free(filter_expression);
2459 free(filter);
2460 free(exclusion);
2461 channel_attr_destroy(attr);
2462 rcu_read_unlock();
2463 return ret;
2464 }
2465
2466 /*
2467 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2468 * We own filter, exclusion, and filter_expression.
2469 */
2470 int cmd_enable_event(struct ltt_session *session,
2471 const struct lttng_domain *domain,
2472 char *channel_name, struct lttng_event *event,
2473 char *filter_expression,
2474 struct lttng_filter_bytecode *filter,
2475 struct lttng_event_exclusion *exclusion,
2476 int wpipe)
2477 {
2478 return _cmd_enable_event(session, domain, channel_name, event,
2479 filter_expression, filter, exclusion, wpipe, false);
2480 }
2481
2482 /*
2483 * Enable an event which is internal to LTTng. An internal should
2484 * never be made visible to clients and are immune to checks such as
2485 * reserved names.
2486 */
2487 static int cmd_enable_event_internal(struct ltt_session *session,
2488 const struct lttng_domain *domain,
2489 char *channel_name, struct lttng_event *event,
2490 char *filter_expression,
2491 struct lttng_filter_bytecode *filter,
2492 struct lttng_event_exclusion *exclusion,
2493 int wpipe)
2494 {
2495 return _cmd_enable_event(session, domain, channel_name, event,
2496 filter_expression, filter, exclusion, wpipe, true);
2497 }
2498
2499 /*
2500 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2501 */
2502 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2503 struct lttng_event **events)
2504 {
2505 int ret;
2506 ssize_t nb_events = 0;
2507
2508 switch (domain) {
2509 case LTTNG_DOMAIN_KERNEL:
2510 nb_events = kernel_list_events(events);
2511 if (nb_events < 0) {
2512 ret = LTTNG_ERR_KERN_LIST_FAIL;
2513 goto error;
2514 }
2515 break;
2516 case LTTNG_DOMAIN_UST:
2517 nb_events = ust_app_list_events(events);
2518 if (nb_events < 0) {
2519 ret = LTTNG_ERR_UST_LIST_FAIL;
2520 goto error;
2521 }
2522 break;
2523 case LTTNG_DOMAIN_LOG4J:
2524 case LTTNG_DOMAIN_JUL:
2525 case LTTNG_DOMAIN_PYTHON:
2526 nb_events = agent_list_events(events, domain);
2527 if (nb_events < 0) {
2528 ret = LTTNG_ERR_UST_LIST_FAIL;
2529 goto error;
2530 }
2531 break;
2532 default:
2533 ret = LTTNG_ERR_UND;
2534 goto error;
2535 }
2536
2537 return nb_events;
2538
2539 error:
2540 /* Return negative value to differentiate return code */
2541 return -ret;
2542 }
2543
2544 /*
2545 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2546 */
2547 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2548 struct lttng_event_field **fields)
2549 {
2550 int ret;
2551 ssize_t nb_fields = 0;
2552
2553 switch (domain) {
2554 case LTTNG_DOMAIN_UST:
2555 nb_fields = ust_app_list_event_fields(fields);
2556 if (nb_fields < 0) {
2557 ret = LTTNG_ERR_UST_LIST_FAIL;
2558 goto error;
2559 }
2560 break;
2561 case LTTNG_DOMAIN_KERNEL:
2562 default: /* fall-through */
2563 ret = LTTNG_ERR_UND;
2564 goto error;
2565 }
2566
2567 return nb_fields;
2568
2569 error:
2570 /* Return negative value to differentiate return code */
2571 return -ret;
2572 }
2573
2574 ssize_t cmd_list_syscalls(struct lttng_event **events)
2575 {
2576 return syscall_table_list(events);
2577 }
2578
2579 /*
2580 * Command LTTNG_LIST_TRACKER_IDS processed by the client thread.
2581 *
2582 * Called with session lock held.
2583 */
2584 ssize_t cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
2585 struct ltt_session *session,
2586 enum lttng_domain_type domain,
2587 struct lttng_tracker_id ***ids)
2588 {
2589 int ret;
2590 ssize_t nr_pids = 0;
2591
2592 switch (domain) {
2593 case LTTNG_DOMAIN_KERNEL:
2594 {
2595 struct ltt_kernel_session *ksess;
2596
2597 ksess = session->kernel_session;
2598 nr_pids = kernel_list_tracker_ids(tracker_type, ksess, ids);
2599 if (nr_pids < 0) {
2600 ret = LTTNG_ERR_KERN_LIST_FAIL;
2601 goto error;
2602 }
2603 break;
2604 }
2605 case LTTNG_DOMAIN_UST:
2606 {
2607 struct ltt_ust_session *usess;
2608
2609 usess = session->ust_session;
2610 nr_pids = trace_ust_list_tracker_ids(tracker_type, usess, ids);
2611 if (nr_pids < 0) {
2612 ret = LTTNG_ERR_UST_LIST_FAIL;
2613 goto error;
2614 }
2615 break;
2616 }
2617 case LTTNG_DOMAIN_LOG4J:
2618 case LTTNG_DOMAIN_JUL:
2619 case LTTNG_DOMAIN_PYTHON:
2620 default:
2621 ret = LTTNG_ERR_UND;
2622 goto error;
2623 }
2624
2625 return nr_pids;
2626
2627 error:
2628 /* Return negative value to differentiate return code */
2629 return -ret;
2630 }
2631
2632 /*
2633 * Command LTTNG_START_TRACE processed by the client thread.
2634 *
2635 * Called with session mutex held.
2636 */
2637 int cmd_start_trace(struct ltt_session *session)
2638 {
2639 enum lttng_error_code ret;
2640 unsigned long nb_chan = 0;
2641 struct ltt_kernel_session *ksession;
2642 struct ltt_ust_session *usess;
2643 const bool session_rotated_after_last_stop =
2644 session->rotated_after_last_stop;
2645 const bool session_cleared_after_last_stop =
2646 session->cleared_after_last_stop;
2647
2648 assert(session);
2649
2650 /* Ease our life a bit ;) */
2651 ksession = session->kernel_session;
2652 usess = session->ust_session;
2653
2654 /* Is the session already started? */
2655 if (session->active) {
2656 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2657 goto error;
2658 }
2659
2660 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2661 !session->current_trace_chunk) {
2662 /*
2663 * A rotation was launched while the session was stopped and
2664 * it has not been completed yet. It is not possible to start
2665 * the session since starting the session here would require a
2666 * rotation from "NULL" to a new trace chunk. That rotation
2667 * would overlap with the ongoing rotation, which is not
2668 * supported.
2669 */
2670 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2671 session->name);
2672 ret = LTTNG_ERR_ROTATION_PENDING;
2673 goto error;
2674 }
2675
2676 /*
2677 * Starting a session without channel is useless since after that it's not
2678 * possible to enable channel thus inform the client.
2679 */
2680 if (usess && usess->domain_global.channels) {
2681 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2682 }
2683 if (ksession) {
2684 nb_chan += ksession->channel_count;
2685 }
2686 if (!nb_chan) {
2687 ret = LTTNG_ERR_NO_CHANNEL;
2688 goto error;
2689 }
2690
2691 session->active = 1;
2692 session->rotated_after_last_stop = false;
2693 session->cleared_after_last_stop = false;
2694 if (session->output_traces && !session->current_trace_chunk) {
2695 if (!session->has_been_started) {
2696 struct lttng_trace_chunk *trace_chunk;
2697
2698 DBG("Creating initial trace chunk of session \"%s\"",
2699 session->name);
2700 trace_chunk = session_create_new_trace_chunk(
2701 session, NULL, NULL, NULL);
2702 if (!trace_chunk) {
2703 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2704 goto error;
2705 }
2706 assert(!session->current_trace_chunk);
2707 ret = session_set_trace_chunk(session, trace_chunk,
2708 NULL);
2709 lttng_trace_chunk_put(trace_chunk);
2710 if (ret) {
2711 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2712 goto error;
2713 }
2714 } else {
2715 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2716 session->name);
2717 /*
2718 * Rotate existing streams into the new chunk.
2719 * This is a "quiet" rotation has no client has
2720 * explicitly requested this operation.
2721 *
2722 * There is also no need to wait for the rotation
2723 * to complete as it will happen immediately. No data
2724 * was produced as the session was stopped, so the
2725 * rotation should happen on reception of the command.
2726 */
2727 ret = cmd_rotate_session(session, NULL, true,
2728 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2729 if (ret != LTTNG_OK) {
2730 goto error;
2731 }
2732 }
2733 }
2734
2735 /* Kernel tracing */
2736 if (ksession != NULL) {
2737 DBG("Start kernel tracing session %s", session->name);
2738 ret = start_kernel_session(ksession);
2739 if (ret != LTTNG_OK) {
2740 goto error;
2741 }
2742 }
2743
2744 /* Flag session that trace should start automatically */
2745 if (usess) {
2746 int int_ret = ust_app_start_trace_all(usess);
2747
2748 if (int_ret < 0) {
2749 ret = LTTNG_ERR_UST_START_FAIL;
2750 goto error;
2751 }
2752 }
2753
2754 /*
2755 * Clear the flag that indicates that a rotation was done while the
2756 * session was stopped.
2757 */
2758 session->rotated_after_last_stop = false;
2759
2760 if (session->rotate_timer_period) {
2761 int int_ret = timer_session_rotation_schedule_timer_start(
2762 session, session->rotate_timer_period);
2763
2764 if (int_ret < 0) {
2765 ERR("Failed to enable rotate timer");
2766 ret = LTTNG_ERR_UNK;
2767 goto error;
2768 }
2769 }
2770
2771 ret = LTTNG_OK;
2772
2773 error:
2774 if (ret == LTTNG_OK) {
2775 /* Flag this after a successful start. */
2776 session->has_been_started |= 1;
2777 } else {
2778 session->active = 0;
2779 /* Restore initial state on error. */
2780 session->rotated_after_last_stop =
2781 session_rotated_after_last_stop;
2782 session->cleared_after_last_stop =
2783 session_cleared_after_last_stop;
2784 }
2785 return ret;
2786 }
2787
2788 /*
2789 * Command LTTNG_STOP_TRACE processed by the client thread.
2790 */
2791 int cmd_stop_trace(struct ltt_session *session)
2792 {
2793 int ret;
2794 struct ltt_kernel_session *ksession;
2795 struct ltt_ust_session *usess;
2796
2797 assert(session);
2798
2799 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2800 /* Short cut */
2801 ksession = session->kernel_session;
2802 usess = session->ust_session;
2803
2804 /* Session is not active. Skip everythong and inform the client. */
2805 if (!session->active) {
2806 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2807 goto error;
2808 }
2809
2810 ret = stop_kernel_session(ksession);
2811 if (ret != LTTNG_OK) {
2812 goto error;
2813 }
2814
2815 if (usess && usess->active) {
2816 ret = ust_app_stop_trace_all(usess);
2817 if (ret < 0) {
2818 ret = LTTNG_ERR_UST_STOP_FAIL;
2819 goto error;
2820 }
2821 }
2822
2823 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2824 session->id);
2825 /* Flag inactive after a successful stop. */
2826 session->active = 0;
2827 ret = LTTNG_OK;
2828
2829 error:
2830 return ret;
2831 }
2832
2833 /*
2834 * Set the base_path of the session only if subdir of a control uris is set.
2835 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2836 */
2837 static int set_session_base_path_from_uris(struct ltt_session *session,
2838 size_t nb_uri,
2839 struct lttng_uri *uris)
2840 {
2841 int ret;
2842 size_t i;
2843
2844 for (i = 0; i < nb_uri; i++) {
2845 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2846 uris[i].subdir[0] == '\0') {
2847 /* Not interested in these URIs */
2848 continue;
2849 }
2850
2851 if (session->base_path != NULL) {
2852 free(session->base_path);
2853 session->base_path = NULL;
2854 }
2855
2856 /* Set session base_path */
2857 session->base_path = strdup(uris[i].subdir);
2858 if (!session->base_path) {
2859 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2860 uris[i].subdir, session->name);
2861 ret = LTTNG_ERR_NOMEM;
2862 goto error;
2863 }
2864 DBG2("Setting base path \"%s\" for session \"%s\"",
2865 session->base_path, session->name);
2866 }
2867 ret = LTTNG_OK;
2868 error:
2869 return ret;
2870 }
2871
2872 /*
2873 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2874 */
2875 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2876 struct lttng_uri *uris)
2877 {
2878 int ret, i;
2879 struct ltt_kernel_session *ksess = session->kernel_session;
2880 struct ltt_ust_session *usess = session->ust_session;
2881
2882 assert(session);
2883 assert(uris);
2884 assert(nb_uri > 0);
2885
2886 /* Can't set consumer URI if the session is active. */
2887 if (session->active) {
2888 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2889 goto error;
2890 }
2891
2892 /*
2893 * Set the session base path if any. This is done inside
2894 * cmd_set_consumer_uri to preserve backward compatibility of the
2895 * previous session creation api vs the session descriptor api.
2896 */
2897 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2898 if (ret != LTTNG_OK) {
2899 goto error;
2900 }
2901
2902 /* Set the "global" consumer URIs */
2903 for (i = 0; i < nb_uri; i++) {
2904 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2905 LTTNG_DOMAIN_NONE);
2906 if (ret != LTTNG_OK) {
2907 goto error;
2908 }
2909 }
2910
2911 /* Set UST session URIs */
2912 if (session->ust_session) {
2913 for (i = 0; i < nb_uri; i++) {
2914 ret = add_uri_to_consumer(session,
2915 session->ust_session->consumer,
2916 &uris[i], LTTNG_DOMAIN_UST);
2917 if (ret != LTTNG_OK) {
2918 goto error;
2919 }
2920 }
2921 }
2922
2923 /* Set kernel session URIs */
2924 if (session->kernel_session) {
2925 for (i = 0; i < nb_uri; i++) {
2926 ret = add_uri_to_consumer(session,
2927 session->kernel_session->consumer,
2928 &uris[i], LTTNG_DOMAIN_KERNEL);
2929 if (ret != LTTNG_OK) {
2930 goto error;
2931 }
2932 }
2933 }
2934
2935 /*
2936 * Make sure to set the session in output mode after we set URI since a
2937 * session can be created without URL (thus flagged in no output mode).
2938 */
2939 session->output_traces = 1;
2940 if (ksess) {
2941 ksess->output_traces = 1;
2942 }
2943
2944 if (usess) {
2945 usess->output_traces = 1;
2946 }
2947
2948 /* All good! */
2949 ret = LTTNG_OK;
2950
2951 error:
2952 return ret;
2953 }
2954
2955 static
2956 enum lttng_error_code set_session_output_from_descriptor(
2957 struct ltt_session *session,
2958 const struct lttng_session_descriptor *descriptor)
2959 {
2960 int ret;
2961 enum lttng_error_code ret_code = LTTNG_OK;
2962 enum lttng_session_descriptor_type session_type =
2963 lttng_session_descriptor_get_type(descriptor);
2964 enum lttng_session_descriptor_output_type output_type =
2965 lttng_session_descriptor_get_output_type(descriptor);
2966 struct lttng_uri uris[2] = {};
2967 size_t uri_count = 0;
2968
2969 switch (output_type) {
2970 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2971 goto end;
2972 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2973 lttng_session_descriptor_get_local_output_uri(descriptor,
2974 &uris[0]);
2975 uri_count = 1;
2976 break;
2977 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2978 lttng_session_descriptor_get_network_output_uris(descriptor,
2979 &uris[0], &uris[1]);
2980 uri_count = 2;
2981 break;
2982 default:
2983 ret_code = LTTNG_ERR_INVALID;
2984 goto end;
2985 }
2986
2987 switch (session_type) {
2988 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2989 {
2990 struct snapshot_output *new_output = NULL;
2991
2992 new_output = snapshot_output_alloc();
2993 if (!new_output) {
2994 ret_code = LTTNG_ERR_NOMEM;
2995 goto end;
2996 }
2997
2998 ret = snapshot_output_init_with_uri(session,
2999 DEFAULT_SNAPSHOT_MAX_SIZE,
3000 NULL, uris, uri_count, session->consumer,
3001 new_output, &session->snapshot);
3002 if (ret < 0) {
3003 ret_code = (ret == -ENOMEM) ?
3004 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
3005 snapshot_output_destroy(new_output);
3006 goto end;
3007 }
3008 snapshot_add_output(&session->snapshot, new_output);
3009 break;
3010 }
3011 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3012 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3013 {
3014 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
3015 break;
3016 }
3017 default:
3018 ret_code = LTTNG_ERR_INVALID;
3019 goto end;
3020 }
3021 end:
3022 return ret_code;
3023 }
3024
3025 static
3026 enum lttng_error_code cmd_create_session_from_descriptor(
3027 struct lttng_session_descriptor *descriptor,
3028 const lttng_sock_cred *creds,
3029 const char *home_path)
3030 {
3031 int ret;
3032 enum lttng_error_code ret_code;
3033 const char *session_name;
3034 struct ltt_session *new_session = NULL;
3035 enum lttng_session_descriptor_status descriptor_status;
3036
3037 session_lock_list();
3038 if (home_path) {
3039 if (*home_path != '/') {
3040 ERR("Home path provided by client is not absolute");
3041 ret_code = LTTNG_ERR_INVALID;
3042 goto end;
3043 }
3044 }
3045
3046 descriptor_status = lttng_session_descriptor_get_session_name(
3047 descriptor, &session_name);
3048 switch (descriptor_status) {
3049 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3050 break;
3051 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3052 session_name = NULL;
3053 break;
3054 default:
3055 ret_code = LTTNG_ERR_INVALID;
3056 goto end;
3057 }
3058
3059 ret_code = session_create(session_name, creds->uid, creds->gid,
3060 &new_session);
3061 if (ret_code != LTTNG_OK) {
3062 goto end;
3063 }
3064
3065 if (!session_name) {
3066 ret = lttng_session_descriptor_set_session_name(descriptor,
3067 new_session->name);
3068 if (ret) {
3069 ret_code = LTTNG_ERR_SESSION_FAIL;
3070 goto end;
3071 }
3072 }
3073
3074 if (!lttng_session_descriptor_is_output_destination_initialized(
3075 descriptor)) {
3076 /*
3077 * Only include the session's creation time in the output
3078 * destination if the name of the session itself was
3079 * not auto-generated.
3080 */
3081 ret_code = lttng_session_descriptor_set_default_output(
3082 descriptor,
3083 session_name ? &new_session->creation_time : NULL,
3084 home_path);
3085 if (ret_code != LTTNG_OK) {
3086 goto end;
3087 }
3088 } else {
3089 new_session->has_user_specified_directory =
3090 lttng_session_descriptor_has_output_directory(
3091 descriptor);
3092 }
3093
3094 switch (lttng_session_descriptor_get_type(descriptor)) {
3095 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3096 new_session->snapshot_mode = 1;
3097 break;
3098 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3099 new_session->live_timer =
3100 lttng_session_descriptor_live_get_timer_interval(
3101 descriptor);
3102 break;
3103 default:
3104 break;
3105 }
3106
3107 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3108 if (ret_code != LTTNG_OK) {
3109 goto end;
3110 }
3111 new_session->consumer->enabled = 1;
3112 ret_code = LTTNG_OK;
3113 end:
3114 /* Release reference provided by the session_create function. */
3115 session_put(new_session);
3116 if (ret_code != LTTNG_OK && new_session) {
3117 /* Release the global reference on error. */
3118 session_destroy(new_session);
3119 }
3120 session_unlock_list();
3121 return ret_code;
3122 }
3123
3124 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3125 struct lttng_session_descriptor **return_descriptor)
3126 {
3127 int ret;
3128 size_t payload_size;
3129 struct lttng_dynamic_buffer payload;
3130 struct lttng_buffer_view home_dir_view;
3131 struct lttng_buffer_view session_descriptor_view;
3132 struct lttng_session_descriptor *session_descriptor = NULL;
3133 enum lttng_error_code ret_code;
3134
3135 lttng_dynamic_buffer_init(&payload);
3136 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
3137 LTTNG_PATH_MAX) {
3138 ret_code = LTTNG_ERR_INVALID;
3139 goto error;
3140 }
3141 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3142 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3143 ret_code = LTTNG_ERR_INVALID;
3144 goto error;
3145 }
3146
3147 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3148 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3149 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3150 if (ret) {
3151 ret_code = LTTNG_ERR_NOMEM;
3152 goto error;
3153 }
3154
3155 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3156 if (ret <= 0) {
3157 ERR("Reception of session descriptor failed, aborting.");
3158 ret_code = LTTNG_ERR_SESSION_FAIL;
3159 goto error;
3160 }
3161
3162 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3163 &payload,
3164 0,
3165 cmd_ctx->lsm->u.create_session.home_dir_size);
3166 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3167 &payload,
3168 cmd_ctx->lsm->u.create_session.home_dir_size,
3169 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3170
3171 ret = lttng_session_descriptor_create_from_buffer(
3172 &session_descriptor_view, &session_descriptor);
3173 if (ret < 0) {
3174 ERR("Failed to create session descriptor from payload of \"create session\" command");
3175 ret_code = LTTNG_ERR_INVALID;
3176 goto error;
3177 }
3178
3179 /*
3180 * Sets the descriptor's auto-generated properties (name, output) if
3181 * needed.
3182 */
3183 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3184 &cmd_ctx->creds,
3185 home_dir_view.size ? home_dir_view.data : NULL);
3186 if (ret_code != LTTNG_OK) {
3187 goto error;
3188 }
3189
3190 ret_code = LTTNG_OK;
3191 *return_descriptor = session_descriptor;
3192 session_descriptor = NULL;
3193 error:
3194 lttng_dynamic_buffer_reset(&payload);
3195 lttng_session_descriptor_destroy(session_descriptor);
3196 return ret_code;
3197 }
3198
3199 static
3200 void cmd_destroy_session_reply(const struct ltt_session *session,
3201 void *_reply_context)
3202 {
3203 int ret;
3204 ssize_t comm_ret;
3205 const struct cmd_destroy_session_reply_context *reply_context =
3206 _reply_context;
3207 struct lttng_dynamic_buffer payload;
3208 struct lttcomm_session_destroy_command_header cmd_header;
3209 struct lttng_trace_archive_location *location = NULL;
3210 struct lttcomm_lttng_msg llm = {
3211 .cmd_type = LTTNG_DESTROY_SESSION,
3212 .ret_code = reply_context->destruction_status,
3213 .pid = UINT32_MAX,
3214 .cmd_header_size =
3215 sizeof(struct lttcomm_session_destroy_command_header),
3216 .data_size = 0,
3217 };
3218 size_t payload_size_before_location;
3219
3220 lttng_dynamic_buffer_init(&payload);
3221
3222 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3223 if (ret) {
3224 ERR("Failed to append session destruction message");
3225 goto error;
3226 }
3227
3228 cmd_header.rotation_state =
3229 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3230 session->rotation_state :
3231 LTTNG_ROTATION_STATE_NO_ROTATION);
3232 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3233 sizeof(cmd_header));
3234 if (ret) {
3235 ERR("Failed to append session destruction command header");
3236 goto error;
3237 }
3238
3239 if (!reply_context->implicit_rotation_on_destroy) {
3240 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3241 session->name);
3242 goto send_reply;
3243 }
3244 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3245 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3246 session->name);
3247 goto send_reply;
3248 }
3249
3250 location = session_get_trace_archive_location(session);
3251 if (!location) {
3252 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3253 session->name);
3254 goto error;
3255 }
3256
3257 payload_size_before_location = payload.size;
3258 comm_ret = lttng_trace_archive_location_serialize(location,
3259 &payload);
3260 if (comm_ret < 0) {
3261 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3262 session->name);
3263 goto error;
3264 }
3265 /* Update the message to indicate the location's length. */
3266 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3267 payload.size - payload_size_before_location;
3268 send_reply:
3269 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3270 payload.data, payload.size);
3271 if (comm_ret != (ssize_t) payload.size) {
3272 ERR("Failed to send result of the destruction of session \"%s\" to client",
3273 session->name);
3274 }
3275 error:
3276 ret = close(reply_context->reply_sock_fd);
3277 if (ret) {
3278 PERROR("Failed to close client socket in deferred session destroy reply");
3279 }
3280 lttng_dynamic_buffer_reset(&payload);
3281 free(_reply_context);
3282 }
3283
3284 /*
3285 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3286 *
3287 * Called with session lock held.
3288 */
3289 int cmd_destroy_session(struct ltt_session *session,
3290 struct notification_thread_handle *notification_thread_handle,
3291 int *sock_fd)
3292 {
3293 int ret;
3294 enum lttng_error_code destruction_last_error = LTTNG_OK;
3295 struct cmd_destroy_session_reply_context *reply_context = NULL;
3296
3297 if (sock_fd) {
3298 reply_context = zmalloc(sizeof(*reply_context));
3299 if (!reply_context) {
3300 ret = LTTNG_ERR_NOMEM;
3301 goto end;
3302 }
3303 reply_context->reply_sock_fd = *sock_fd;
3304 }
3305
3306 /* Safety net */
3307 assert(session);
3308
3309 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3310 session->id);
3311 if (session->active) {
3312 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3313 session->name);
3314 ret = cmd_stop_trace(session);
3315 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3316 /* Carry on with the destruction of the session. */
3317 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3318 session->name, lttng_strerror(-ret));
3319 destruction_last_error = ret;
3320 }
3321 }
3322
3323 if (session->rotation_schedule_timer_enabled) {
3324 if (timer_session_rotation_schedule_timer_stop(
3325 session)) {
3326 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3327 session->name);
3328 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3329 }
3330 }
3331
3332 if (session->rotate_size) {
3333 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3334 session->rotate_size = 0;
3335 }
3336
3337 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3338 /*
3339 * Perform a last rotation on destruction if rotations have
3340 * occurred during the session's lifetime.
3341 */
3342 ret = cmd_rotate_session(session, NULL, false,
3343 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3344 if (ret != LTTNG_OK) {
3345 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3346 session->name, lttng_strerror(-ret));
3347 destruction_last_error = -ret;
3348 }
3349 if (reply_context) {
3350 reply_context->implicit_rotation_on_destroy = true;
3351 }
3352 } else if (session->has_been_started && session->current_trace_chunk) {
3353 /*
3354 * The user has not triggered a session rotation. However, to
3355 * ensure all data has been consumed, the session is rotated
3356 * to a 'null' trace chunk before it is destroyed.
3357 *
3358 * This is a "quiet" rotation meaning that no notification is
3359 * emitted and no renaming of the current trace chunk takes
3360 * place.
3361 */
3362 ret = cmd_rotate_session(session, NULL, true,
3363 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3364 if (ret != LTTNG_OK) {
3365 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3366 session->name, lttng_strerror(-ret));
3367 destruction_last_error = -ret;
3368 }
3369 }
3370
3371 if (session->shm_path[0]) {
3372 /*
3373 * When a session is created with an explicit shm_path,
3374 * the consumer daemon will create its shared memory files
3375 * at that location and will *not* unlink them. This is normal
3376 * as the intention of that feature is to make it possible
3377 * to retrieve the content of those files should a crash occur.
3378 *
3379 * To ensure the content of those files can be used, the
3380 * sessiond daemon will replicate the content of the metadata
3381 * cache in a metadata file.
3382 *
3383 * On clean-up, it is expected that the consumer daemon will
3384 * unlink the shared memory files and that the session daemon
3385 * will unlink the metadata file. Then, the session's directory
3386 * in the shm path can be removed.
3387 *
3388 * Unfortunately, a flaw in the design of the sessiond's and
3389 * consumerd's tear down of channels makes it impossible to
3390 * determine when the sessiond _and_ the consumerd have both
3391 * destroyed their representation of a channel. For one, the
3392 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3393 * callbacks in both daemons.
3394 *
3395 * However, it is also impossible for the sessiond to know when
3396 * the consumer daemon is done destroying its channel(s) since
3397 * it occurs as a reaction to the closing of the channel's file
3398 * descriptor. There is no resulting communication initiated
3399 * from the consumerd to the sessiond to confirm that the
3400 * operation is completed (and was successful).
3401 *
3402 * Until this is all fixed, the session daemon checks for the
3403 * removal of the session's shm path which makes it possible
3404 * to safely advertise a session as having been destroyed.
3405 *
3406 * Prior to this fix, it was not possible to reliably save
3407 * a session making use of the --shm-path option, destroy it,
3408 * and load it again. This is because the creation of the
3409 * session would fail upon seeing the session's shm path
3410 * already in existence.
3411 *
3412 * Note that none of the error paths in the check for the
3413 * directory's existence return an error. This is normal
3414 * as there isn't much that can be done. The session will
3415 * be destroyed properly, except that we can't offer the
3416 * guarantee that the same session can be re-created.
3417 */
3418 current_completion_handler = &destroy_completion_handler.handler;
3419 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3420 session->shm_path,
3421 sizeof(destroy_completion_handler.shm_path));
3422 assert(!ret);
3423 }
3424
3425 /*
3426 * The session is destroyed. However, note that the command context
3427 * still holds a reference to the session, thus delaying its destruction
3428 * _at least_ up to the point when that reference is released.
3429 */
3430 session_destroy(session);
3431 if (reply_context) {
3432 reply_context->destruction_status = destruction_last_error;
3433 ret = session_add_destroy_notifier(session,
3434 cmd_destroy_session_reply,
3435 (void *) reply_context);
3436 if (ret) {
3437 ret = LTTNG_ERR_FATAL;
3438 goto end;
3439 } else {
3440 *sock_fd = -1;
3441 }
3442 }
3443 ret = LTTNG_OK;
3444 end:
3445 return ret;
3446 }
3447
3448 /*
3449 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3450 */
3451 int cmd_register_consumer(struct ltt_session *session,
3452 enum lttng_domain_type domain, const char *sock_path,
3453 struct consumer_data *cdata)
3454 {
3455 int ret, sock;
3456 struct consumer_socket *socket = NULL;
3457
3458 assert(session);
3459 assert(cdata);
3460 assert(sock_path);
3461
3462 switch (domain) {
3463 case LTTNG_DOMAIN_KERNEL:
3464 {
3465 struct ltt_kernel_session *ksess = session->kernel_session;
3466
3467 assert(ksess);
3468
3469 /* Can't register a consumer if there is already one */
3470 if (ksess->consumer_fds_sent != 0) {
3471 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3472 goto error;
3473 }
3474
3475 sock = lttcomm_connect_unix_sock(sock_path);
3476 if (sock < 0) {
3477 ret = LTTNG_ERR_CONNECT_FAIL;
3478 goto error;
3479 }
3480 cdata->cmd_sock = sock;
3481
3482 socket = consumer_allocate_socket(&cdata->cmd_sock);
3483 if (socket == NULL) {
3484 ret = close(sock);
3485 if (ret < 0) {
3486 PERROR("close register consumer");
3487 }
3488 cdata->cmd_sock = -1;
3489 ret = LTTNG_ERR_FATAL;
3490 goto error;
3491 }
3492
3493 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3494 if (socket->lock == NULL) {
3495 PERROR("zmalloc pthread mutex");
3496 ret = LTTNG_ERR_FATAL;
3497 goto error;
3498 }
3499 pthread_mutex_init(socket->lock, NULL);
3500 socket->registered = 1;
3501
3502 rcu_read_lock();
3503 consumer_add_socket(socket, ksess->consumer);
3504 rcu_read_unlock();
3505
3506 pthread_mutex_lock(&cdata->pid_mutex);
3507 cdata->pid = -1;
3508 pthread_mutex_unlock(&cdata->pid_mutex);
3509
3510 break;
3511 }
3512 default:
3513 /* TODO: Userspace tracing */
3514 ret = LTTNG_ERR_UND;
3515 goto error;
3516 }
3517
3518 return LTTNG_OK;
3519
3520 error:
3521 if (socket) {
3522 consumer_destroy_socket(socket);
3523 }
3524 return ret;
3525 }
3526
3527 /*
3528 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3529 */
3530 ssize_t cmd_list_domains(struct ltt_session *session,
3531 struct lttng_domain **domains)
3532 {
3533 int ret, index = 0;
3534 ssize_t nb_dom = 0;
3535 struct agent *agt;
3536 struct lttng_ht_iter iter;
3537
3538 if (session->kernel_session != NULL) {
3539 DBG3("Listing domains found kernel domain");
3540 nb_dom++;
3541 }
3542
3543 if (session->ust_session != NULL) {
3544 DBG3("Listing domains found UST global domain");
3545 nb_dom++;
3546
3547 rcu_read_lock();
3548 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3549 agt, node.node) {
3550 if (agt->being_used) {
3551 nb_dom++;
3552 }
3553 }
3554 rcu_read_unlock();
3555 }
3556
3557 if (!nb_dom) {
3558 goto end;
3559 }
3560
3561 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3562 if (*domains == NULL) {
3563 ret = LTTNG_ERR_FATAL;
3564 goto error;
3565 }
3566
3567 if (session->kernel_session != NULL) {
3568 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3569
3570 /* Kernel session buffer type is always GLOBAL */
3571 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3572
3573 index++;
3574 }
3575
3576 if (session->ust_session != NULL) {
3577 (*domains)[index].type = LTTNG_DOMAIN_UST;
3578 (*domains)[index].buf_type = session->ust_session->buffer_type;
3579 index++;
3580
3581 rcu_read_lock();
3582 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3583 agt, node.node) {
3584 if (agt->being_used) {
3585 (*domains)[index].type = agt->domain;
3586 (*domains)[index].buf_type = session->ust_session->buffer_type;
3587 index++;
3588 }
3589 }
3590 rcu_read_unlock();
3591 }
3592 end:
3593 return nb_dom;
3594
3595 error:
3596 /* Return negative value to differentiate return code */
3597 return -ret;
3598 }
3599
3600
3601 /*
3602 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3603 */
3604 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3605 struct ltt_session *session, struct lttng_channel **channels)
3606 {
3607 ssize_t nb_chan = 0, payload_size = 0, ret;
3608
3609 switch (domain) {
3610 case LTTNG_DOMAIN_KERNEL:
3611 if (session->kernel_session != NULL) {
3612 nb_chan = session->kernel_session->channel_count;
3613 }
3614 DBG3("Number of kernel channels %zd", nb_chan);
3615 if (nb_chan <= 0) {
3616 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3617 goto end;
3618 }
3619 break;
3620 case LTTNG_DOMAIN_UST:
3621 if (session->ust_session != NULL) {
3622 rcu_read_lock();
3623 nb_chan = lttng_ht_get_count(
3624 session->ust_session->domain_global.channels);
3625 rcu_read_unlock();
3626 }
3627 DBG3("Number of UST global channels %zd", nb_chan);
3628 if (nb_chan < 0) {
3629 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3630 goto end;
3631 }
3632 break;
3633 default:
3634 ret = -LTTNG_ERR_UND;
3635 goto end;
3636 }
3637
3638 if (nb_chan > 0) {
3639 const size_t channel_size = sizeof(struct lttng_channel) +
3640 sizeof(struct lttng_channel_extended);
3641 struct lttng_channel_extended *channel_exts;
3642
3643 payload_size = nb_chan * channel_size;
3644 *channels = zmalloc(payload_size);
3645 if (*channels == NULL) {
3646 ret = -LTTNG_ERR_FATAL;
3647 goto end;
3648 }
3649
3650 channel_exts = ((void *) *channels) +
3651 (nb_chan * sizeof(struct lttng_channel));
3652 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3653 if (ret != LTTNG_OK) {
3654 free(*channels);
3655 *channels = NULL;
3656 goto end;
3657 }
3658 } else {
3659 *channels = NULL;
3660 }
3661
3662 ret = payload_size;
3663 end:
3664 return ret;
3665 }
3666
3667 /*
3668 * Command LTTNG_LIST_EVENTS processed by the client thread.
3669 */
3670 ssize_t cmd_list_events(enum lttng_domain_type domain,
3671 struct ltt_session *session, char *channel_name,
3672 struct lttng_event **events, size_t *total_size)
3673 {
3674 int ret = 0;
3675 ssize_t nb_event = 0;
3676
3677 switch (domain) {
3678 case LTTNG_DOMAIN_KERNEL:
3679 if (session->kernel_session != NULL) {
3680 nb_event = list_lttng_kernel_events(channel_name,
3681 session->kernel_session, events,
3682 total_size);
3683 }
3684 break;
3685 case LTTNG_DOMAIN_UST:
3686 {
3687 if (session->ust_session != NULL) {
3688 nb_event = list_lttng_ust_global_events(channel_name,
3689 &session->ust_session->domain_global, events,
3690 total_size);
3691 }
3692 break;
3693 }
3694 case LTTNG_DOMAIN_LOG4J:
3695 case LTTNG_DOMAIN_JUL:
3696 case LTTNG_DOMAIN_PYTHON:
3697 if (session->ust_session) {
3698 struct lttng_ht_iter iter;
3699 struct agent *agt;
3700
3701 rcu_read_lock();
3702 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3703 &iter.iter, agt, node.node) {
3704 if (agt->domain == domain) {
3705 nb_event = list_lttng_agent_events(
3706 agt, events,
3707 total_size);
3708 break;
3709 }
3710 }
3711 rcu_read_unlock();
3712 }
3713 break;
3714 default:
3715 ret = LTTNG_ERR_UND;
3716 goto error;
3717 }
3718
3719 return nb_event;
3720
3721 error:
3722 /* Return negative value to differentiate return code */
3723 return -ret;
3724 }
3725
3726 /*
3727 * Using the session list, filled a lttng_session array to send back to the
3728 * client for session listing.
3729 *
3730 * The session list lock MUST be acquired before calling this function. Use
3731 * session_lock_list() and session_unlock_list().
3732 */
3733 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3734 size_t session_count, uid_t uid, gid_t gid)
3735 {
3736 int ret;
3737 unsigned int i = 0;
3738 struct ltt_session *session;
3739 struct ltt_session_list *list = session_get_list();
3740 struct lttng_session_extended *extended =
3741 (typeof(extended)) (&sessions[session_count]);
3742
3743 DBG("Getting all available session for UID %d GID %d",
3744 uid, gid);
3745 /*
3746 * Iterate over session list and append data after the control struct in
3747 * the buffer.
3748 */
3749 cds_list_for_each_entry(session, &list->head, list) {
3750 if (!session_get(session)) {
3751 continue;
3752 }
3753 /*
3754 * Only list the sessions the user can control.
3755 */
3756 if (!session_access_ok(session, uid, gid) ||
3757 session->destroyed) {
3758 session_put(session);
3759 continue;
3760 }
3761
3762 struct ltt_kernel_session *ksess = session->kernel_session;
3763 struct ltt_