5e522d6fe0886108b87df756e930a6519a5a8a09
[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 * SPDX-License-Identifier: GPL-2.0-only
6 *
7 */
8
9 #define _LGPL_SOURCE
10 #include <assert.h>
11 #include <inttypes.h>
12 #include <urcu/list.h>
13 #include <urcu/uatomic.h>
14 #include <sys/stat.h>
15 #include <stdio.h>
16
17 #include <common/defaults.h>
18 #include <common/common.h>
19 #include <common/sessiond-comm/sessiond-comm.h>
20 #include <common/relayd/relayd.h>
21 #include <common/utils.h>
22 #include <common/compat/string.h>
23 #include <common/kernel-ctl/kernel-ctl.h>
24 #include <common/dynamic-buffer.h>
25 #include <common/buffer-view.h>
26 #include <common/trace-chunk.h>
27 #include <lttng/location-internal.h>
28 #include <lttng/trigger/trigger-internal.h>
29 #include <lttng/condition/condition.h>
30 #include <lttng/action/action.h>
31 #include <lttng/channel.h>
32 #include <lttng/channel-internal.h>
33 #include <lttng/rotate-internal.h>
34 #include <lttng/location-internal.h>
35 #include <lttng/session-internal.h>
36 #include <lttng/userspace-probe-internal.h>
37 #include <lttng/session-descriptor-internal.h>
38 #include <common/string-utils/string-utils.h>
39
40 #include "channel.h"
41 #include "consumer.h"
42 #include "event.h"
43 #include "health-sessiond.h"
44 #include "kernel.h"
45 #include "kernel-consumer.h"
46 #include "lttng-sessiond.h"
47 #include "utils.h"
48 #include "lttng-syscall.h"
49 #include "agent.h"
50 #include "buffer-registry.h"
51 #include "notification-thread.h"
52 #include "notification-thread-commands.h"
53 #include "rotate.h"
54 #include "rotation-thread.h"
55 #include "timer.h"
56 #include "agent-thread.h"
57
58 #include "cmd.h"
59
60 /* Sleep for 100ms between each check for the shm path's deletion. */
61 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
62
63 struct cmd_destroy_session_reply_context {
64 int reply_sock_fd;
65 bool implicit_rotation_on_destroy;
66 /*
67 * Indicates whether or not an error occurred while launching the
68 * destruction of a session.
69 */
70 enum lttng_error_code destruction_status;
71 };
72
73 static enum lttng_error_code wait_on_path(void *path);
74
75 /*
76 * Command completion handler that is used by the destroy command
77 * when a session that has a non-default shm_path is being destroyed.
78 *
79 * See comment in cmd_destroy_session() for the rationale.
80 */
81 static struct destroy_completion_handler {
82 struct cmd_completion_handler handler;
83 char shm_path[member_sizeof(struct ltt_session, shm_path)];
84 } destroy_completion_handler = {
85 .handler = {
86 .run = wait_on_path,
87 .data = destroy_completion_handler.shm_path
88 },
89 .shm_path = { 0 },
90 };
91
92 static struct cmd_completion_handler *current_completion_handler;
93
94 /*
95 * Used to keep a unique index for each relayd socket created where this value
96 * is associated with streams on the consumer so it can match the right relayd
97 * to send to. It must be accessed with the relayd_net_seq_idx_lock
98 * held.
99 */
100 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
101 static uint64_t relayd_net_seq_idx;
102
103 static int validate_ust_event_name(const char *);
104 static int cmd_enable_event_internal(struct ltt_session *session,
105 const struct lttng_domain *domain,
106 char *channel_name, struct lttng_event *event,
107 char *filter_expression,
108 struct lttng_filter_bytecode *filter,
109 struct lttng_event_exclusion *exclusion,
110 int wpipe);
111
112 /*
113 * Create a session path used by list_lttng_sessions for the case that the
114 * session consumer is on the network.
115 */
116 static int build_network_session_path(char *dst, size_t size,
117 struct ltt_session *session)
118 {
119 int ret, kdata_port, udata_port;
120 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
121 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
122
123 assert(session);
124 assert(dst);
125
126 memset(tmp_urls, 0, sizeof(tmp_urls));
127 memset(tmp_uurl, 0, sizeof(tmp_uurl));
128
129 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
130
131 if (session->kernel_session && session->kernel_session->consumer) {
132 kuri = &session->kernel_session->consumer->dst.net.control;
133 kdata_port = session->kernel_session->consumer->dst.net.data.port;
134 }
135
136 if (session->ust_session && session->ust_session->consumer) {
137 uuri = &session->ust_session->consumer->dst.net.control;
138 udata_port = session->ust_session->consumer->dst.net.data.port;
139 }
140
141 if (uuri == NULL && kuri == NULL) {
142 uri = &session->consumer->dst.net.control;
143 kdata_port = session->consumer->dst.net.data.port;
144 } else if (kuri && uuri) {
145 ret = uri_compare(kuri, uuri);
146 if (ret) {
147 /* Not Equal */
148 uri = kuri;
149 /* Build uuri URL string */
150 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
151 if (ret < 0) {
152 goto error;
153 }
154 } else {
155 uri = kuri;
156 }
157 } else if (kuri && uuri == NULL) {
158 uri = kuri;
159 } else if (uuri && kuri == NULL) {
160 uri = uuri;
161 }
162
163 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
164 if (ret < 0) {
165 goto error;
166 }
167
168 /*
169 * Do we have a UST url set. If yes, this means we have both kernel and UST
170 * to print.
171 */
172 if (*tmp_uurl != '\0') {
173 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
174 tmp_urls, kdata_port, tmp_uurl, udata_port);
175 } else {
176 int dport;
177 if (kuri || (!kuri && !uuri)) {
178 dport = kdata_port;
179 } else {
180 /* No kernel URI, use the UST port. */
181 dport = udata_port;
182 }
183 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
184 }
185
186 error:
187 return ret;
188 }
189
190 /*
191 * Get run-time attributes if the session has been started (discarded events,
192 * lost packets).
193 */
194 static int get_kernel_runtime_stats(struct ltt_session *session,
195 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
196 uint64_t *lost_packets)
197 {
198 int ret;
199
200 if (!session->has_been_started) {
201 ret = 0;
202 *discarded_events = 0;
203 *lost_packets = 0;
204 goto end;
205 }
206
207 ret = consumer_get_discarded_events(session->id, kchan->key,
208 session->kernel_session->consumer,
209 discarded_events);
210 if (ret < 0) {
211 goto end;
212 }
213
214 ret = consumer_get_lost_packets(session->id, kchan->key,
215 session->kernel_session->consumer,
216 lost_packets);
217 if (ret < 0) {
218 goto end;
219 }
220
221 end:
222 return ret;
223 }
224
225 /*
226 * Get run-time attributes if the session has been started (discarded events,
227 * lost packets).
228 */
229 static int get_ust_runtime_stats(struct ltt_session *session,
230 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
231 uint64_t *lost_packets)
232 {
233 int ret;
234 struct ltt_ust_session *usess;
235
236 if (!discarded_events || !lost_packets) {
237 ret = -1;
238 goto end;
239 }
240
241 usess = session->ust_session;
242 assert(discarded_events);
243 assert(lost_packets);
244
245 if (!usess || !session->has_been_started) {
246 *discarded_events = 0;
247 *lost_packets = 0;
248 ret = 0;
249 goto end;
250 }
251
252 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
253 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
254 &usess->buffer_reg_uid_list,
255 usess->consumer, uchan->id,
256 uchan->attr.overwrite,
257 discarded_events,
258 lost_packets);
259 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
260 ret = ust_app_pid_get_channel_runtime_stats(usess,
261 uchan, usess->consumer,
262 uchan->attr.overwrite,
263 discarded_events,
264 lost_packets);
265 if (ret < 0) {
266 goto end;
267 }
268 *discarded_events += uchan->per_pid_closed_app_discarded;
269 *lost_packets += uchan->per_pid_closed_app_lost;
270 } else {
271 ERR("Unsupported buffer type");
272 assert(0);
273 ret = -1;
274 goto end;
275 }
276
277 end:
278 return ret;
279 }
280
281 /*
282 * Fill lttng_channel array of all channels.
283 */
284 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
285 struct ltt_session *session, struct lttng_channel *channels,
286 struct lttng_channel_extended *chan_exts)
287 {
288 int i = 0, ret = 0;
289 struct ltt_kernel_channel *kchan;
290
291 DBG("Listing channels for session %s", session->name);
292
293 switch (domain) {
294 case LTTNG_DOMAIN_KERNEL:
295 /* Kernel channels */
296 if (session->kernel_session != NULL) {
297 cds_list_for_each_entry(kchan,
298 &session->kernel_session->channel_list.head, list) {
299 uint64_t discarded_events, lost_packets;
300 struct lttng_channel_extended *extended;
301
302 extended = (struct lttng_channel_extended *)
303 kchan->channel->attr.extended.ptr;
304
305 ret = get_kernel_runtime_stats(session, kchan,
306 &discarded_events, &lost_packets);
307 if (ret < 0) {
308 goto end;
309 }
310 /* Copy lttng_channel struct to array */
311 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
312 channels[i].enabled = kchan->enabled;
313 chan_exts[i].discarded_events =
314 discarded_events;
315 chan_exts[i].lost_packets = lost_packets;
316 chan_exts[i].monitor_timer_interval =
317 extended->monitor_timer_interval;
318 chan_exts[i].blocking_timeout = 0;
319 i++;
320 }
321 }
322 break;
323 case LTTNG_DOMAIN_UST:
324 {
325 struct lttng_ht_iter iter;
326 struct ltt_ust_channel *uchan;
327
328 rcu_read_lock();
329 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
330 &iter.iter, uchan, node.node) {
331 uint64_t discarded_events = 0, lost_packets = 0;
332
333 if (lttng_strncpy(channels[i].name, uchan->name,
334 LTTNG_SYMBOL_NAME_LEN)) {
335 break;
336 }
337 channels[i].attr.overwrite = uchan->attr.overwrite;
338 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
339 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
340 channels[i].attr.switch_timer_interval =
341 uchan->attr.switch_timer_interval;
342 channels[i].attr.read_timer_interval =
343 uchan->attr.read_timer_interval;
344 channels[i].enabled = uchan->enabled;
345 channels[i].attr.tracefile_size = uchan->tracefile_size;
346 channels[i].attr.tracefile_count = uchan->tracefile_count;
347
348 /*
349 * Map enum lttng_ust_output to enum lttng_event_output.
350 */
351 switch (uchan->attr.output) {
352 case LTTNG_UST_MMAP:
353 channels[i].attr.output = LTTNG_EVENT_MMAP;
354 break;
355 default:
356 /*
357 * LTTNG_UST_MMAP is the only supported UST
358 * output mode.
359 */
360 assert(0);
361 break;
362 }
363
364 chan_exts[i].monitor_timer_interval =
365 uchan->monitor_timer_interval;
366 chan_exts[i].blocking_timeout =
367 uchan->attr.u.s.blocking_timeout;
368
369 ret = get_ust_runtime_stats(session, uchan,
370 &discarded_events, &lost_packets);
371 if (ret < 0) {
372 break;
373 }
374 chan_exts[i].discarded_events = discarded_events;
375 chan_exts[i].lost_packets = lost_packets;
376 i++;
377 }
378 rcu_read_unlock();
379 break;
380 }
381 default:
382 break;
383 }
384
385 end:
386 if (ret < 0) {
387 return -LTTNG_ERR_FATAL;
388 } else {
389 return LTTNG_OK;
390 }
391 }
392
393 static int increment_extended_len(const char *filter_expression,
394 struct lttng_event_exclusion *exclusion,
395 const struct lttng_userspace_probe_location *probe_location,
396 size_t *extended_len)
397 {
398 int ret = 0;
399
400 *extended_len += sizeof(struct lttcomm_event_extended_header);
401
402 if (filter_expression) {
403 *extended_len += strlen(filter_expression) + 1;
404 }
405
406 if (exclusion) {
407 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
408 }
409
410 if (probe_location) {
411 ret = lttng_userspace_probe_location_serialize(probe_location,
412 NULL, NULL);
413 if (ret < 0) {
414 goto end;
415 }
416 *extended_len += ret;
417 }
418 ret = 0;
419 end:
420 return ret;
421 }
422
423 static int append_extended_info(const char *filter_expression,
424 struct lttng_event_exclusion *exclusion,
425 struct lttng_userspace_probe_location *probe_location,
426 void **extended_at)
427 {
428 int ret = 0;
429 size_t filter_len = 0;
430 size_t nb_exclusions = 0;
431 size_t userspace_probe_location_len = 0;
432 struct lttng_dynamic_buffer location_buffer;
433 struct lttcomm_event_extended_header extended_header;
434
435 if (filter_expression) {
436 filter_len = strlen(filter_expression) + 1;
437 }
438
439 if (exclusion) {
440 nb_exclusions = exclusion->count;
441 }
442
443 if (probe_location) {
444 lttng_dynamic_buffer_init(&location_buffer);
445 ret = lttng_userspace_probe_location_serialize(probe_location,
446 &location_buffer, NULL);
447 if (ret < 0) {
448 ret = -1;
449 goto end;
450 }
451 userspace_probe_location_len = location_buffer.size;
452 }
453
454 /* Set header fields */
455 extended_header.filter_len = filter_len;
456 extended_header.nb_exclusions = nb_exclusions;
457 extended_header.userspace_probe_location_len = userspace_probe_location_len;
458
459 /* Copy header */
460 memcpy(*extended_at, &extended_header, sizeof(extended_header));
461 *extended_at += sizeof(extended_header);
462
463 /* Copy filter string */
464 if (filter_expression) {
465 memcpy(*extended_at, filter_expression, filter_len);
466 *extended_at += filter_len;
467 }
468
469 /* Copy exclusion names */
470 if (exclusion) {
471 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
472
473 memcpy(*extended_at, &exclusion->names, len);
474 *extended_at += len;
475 }
476
477 if (probe_location) {
478 memcpy(*extended_at, location_buffer.data, location_buffer.size);
479 *extended_at += location_buffer.size;
480 lttng_dynamic_buffer_reset(&location_buffer);
481 }
482 ret = 0;
483 end:
484 return ret;
485 }
486
487 /*
488 * Create a list of agent domain events.
489 *
490 * Return number of events in list on success or else a negative value.
491 */
492 static int list_lttng_agent_events(struct agent *agt,
493 struct lttng_event **events, size_t *total_size)
494 {
495 int i = 0, ret = 0;
496 unsigned int nb_event = 0;
497 struct agent_event *event;
498 struct lttng_event *tmp_events = NULL;
499 struct lttng_ht_iter iter;
500 size_t extended_len = 0;
501 void *extended_at;
502
503 assert(agt);
504 assert(events);
505
506 DBG3("Listing agent events");
507
508 rcu_read_lock();
509 nb_event = lttng_ht_get_count(agt->events);
510 rcu_read_unlock();
511 if (nb_event == 0) {
512 ret = nb_event;
513 *total_size = 0;
514 goto error;
515 }
516
517 /* Compute required extended infos size */
518 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
519
520 /*
521 * This is only valid because the commands which add events are
522 * processed in the same thread as the listing.
523 */
524 rcu_read_lock();
525 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
526 ret = increment_extended_len(event->filter_expression, NULL, NULL,
527 &extended_len);
528 if (ret) {
529 DBG("Error computing the length of extended info message");
530 ret = -LTTNG_ERR_FATAL;
531 goto error;
532 }
533 }
534 rcu_read_unlock();
535
536 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
537 tmp_events = zmalloc(*total_size);
538 if (!tmp_events) {
539 PERROR("zmalloc agent events session");
540 ret = -LTTNG_ERR_FATAL;
541 goto error;
542 }
543
544 extended_at = ((uint8_t *) tmp_events) +
545 nb_event * sizeof(struct lttng_event);
546
547 rcu_read_lock();
548 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
549 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
550 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
551 tmp_events[i].enabled = event->enabled;
552 tmp_events[i].loglevel = event->loglevel_value;
553 tmp_events[i].loglevel_type = event->loglevel_type;
554 i++;
555
556 /* Append extended info */
557 ret = append_extended_info(event->filter_expression, NULL, NULL,
558 &extended_at);
559 if (ret) {
560 DBG("Error appending extended info message");
561 ret = -LTTNG_ERR_FATAL;
562 goto error;
563 }
564 }
565
566 *events = tmp_events;
567 ret = nb_event;
568 assert(nb_event == i);
569
570 end:
571 rcu_read_unlock();
572 return ret;
573 error:
574 free(tmp_events);
575 goto end;
576 }
577
578 /*
579 * Create a list of ust global domain events.
580 */
581 static int list_lttng_ust_global_events(char *channel_name,
582 struct ltt_ust_domain_global *ust_global,
583 struct lttng_event **events, size_t *total_size)
584 {
585 int i = 0, ret = 0;
586 unsigned int nb_event = 0;
587 struct lttng_ht_iter iter;
588 struct lttng_ht_node_str *node;
589 struct ltt_ust_channel *uchan;
590 struct ltt_ust_event *uevent;
591 struct lttng_event *tmp;
592 size_t extended_len = 0;
593 void *extended_at;
594
595 DBG("Listing UST global events for channel %s", channel_name);
596
597 rcu_read_lock();
598
599 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
600 node = lttng_ht_iter_get_node_str(&iter);
601 if (node == NULL) {
602 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
603 goto end;
604 }
605
606 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
607
608 nb_event = lttng_ht_get_count(uchan->events);
609 if (nb_event == 0) {
610 ret = nb_event;
611 *total_size = 0;
612 goto end;
613 }
614
615 DBG3("Listing UST global %d events", nb_event);
616
617 /* Compute required extended infos size */
618 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
619 if (uevent->internal) {
620 nb_event--;
621 continue;
622 }
623
624 ret = increment_extended_len(uevent->filter_expression,
625 uevent->exclusion, NULL, &extended_len);
626 if (ret) {
627 DBG("Error computing the length of extended info message");
628 ret = -LTTNG_ERR_FATAL;
629 goto end;
630 }
631 }
632 if (nb_event == 0) {
633 /* All events are internal, skip. */
634 ret = 0;
635 *total_size = 0;
636 goto end;
637 }
638
639 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
640 tmp = zmalloc(*total_size);
641 if (tmp == NULL) {
642 ret = -LTTNG_ERR_FATAL;
643 goto end;
644 }
645
646 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
647
648 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
649 if (uevent->internal) {
650 /* This event should remain hidden from clients */
651 continue;
652 }
653 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
654 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
655 tmp[i].enabled = uevent->enabled;
656
657 switch (uevent->attr.instrumentation) {
658 case LTTNG_UST_TRACEPOINT:
659 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
660 break;
661 case LTTNG_UST_PROBE:
662 tmp[i].type = LTTNG_EVENT_PROBE;
663 break;
664 case LTTNG_UST_FUNCTION:
665 tmp[i].type = LTTNG_EVENT_FUNCTION;
666 break;
667 }
668
669 tmp[i].loglevel = uevent->attr.loglevel;
670 switch (uevent->attr.loglevel_type) {
671 case LTTNG_UST_LOGLEVEL_ALL:
672 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
673 break;
674 case LTTNG_UST_LOGLEVEL_RANGE:
675 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
676 break;
677 case LTTNG_UST_LOGLEVEL_SINGLE:
678 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
679 break;
680 }
681 if (uevent->filter) {
682 tmp[i].filter = 1;
683 }
684 if (uevent->exclusion) {
685 tmp[i].exclusion = 1;
686 }
687 i++;
688
689 /* Append extended info */
690 ret = append_extended_info(uevent->filter_expression,
691 uevent->exclusion, NULL, &extended_at);
692 if (ret) {
693 DBG("Error appending extended info message");
694 ret = -LTTNG_ERR_FATAL;
695 goto end;
696 }
697 }
698
699 ret = nb_event;
700 *events = tmp;
701 end:
702 rcu_read_unlock();
703 return ret;
704 }
705
706 /*
707 * Fill lttng_event array of all kernel events in the channel.
708 */
709 static int list_lttng_kernel_events(char *channel_name,
710 struct ltt_kernel_session *kernel_session,
711 struct lttng_event **events, size_t *total_size)
712 {
713 int i = 0, ret;
714 unsigned int nb_event;
715 struct ltt_kernel_event *event;
716 struct ltt_kernel_channel *kchan;
717 size_t extended_len = 0;
718 void *extended_at;
719
720 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
721 if (kchan == NULL) {
722 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
723 goto error;
724 }
725
726 nb_event = kchan->event_count;
727
728 DBG("Listing events for channel %s", kchan->channel->name);
729
730 if (nb_event == 0) {
731 *total_size = 0;
732 *events = NULL;
733 goto end;
734 }
735
736 /* Compute required extended infos size */
737 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
738 ret = increment_extended_len(event->filter_expression, NULL,
739 event->userspace_probe_location,
740 &extended_len);
741 if (ret) {
742 DBG("Error computing the length of extended info message");
743 ret = -LTTNG_ERR_FATAL;
744 goto error;
745 }
746 }
747
748 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
749 *events = zmalloc(*total_size);
750 if (*events == NULL) {
751 ret = -LTTNG_ERR_FATAL;
752 goto error;
753 }
754
755 extended_at = ((void *) *events) +
756 nb_event * sizeof(struct lttng_event);
757
758 /* Kernel channels */
759 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
760 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
761 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
762 (*events)[i].enabled = event->enabled;
763 (*events)[i].filter =
764 (unsigned char) !!event->filter_expression;
765
766 switch (event->event->instrumentation) {
767 case LTTNG_KERNEL_TRACEPOINT:
768 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
769 break;
770 case LTTNG_KERNEL_KRETPROBE:
771 (*events)[i].type = LTTNG_EVENT_FUNCTION;
772 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
773 sizeof(struct lttng_kernel_kprobe));
774 break;
775 case LTTNG_KERNEL_KPROBE:
776 (*events)[i].type = LTTNG_EVENT_PROBE;
777 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
778 sizeof(struct lttng_kernel_kprobe));
779 break;
780 case LTTNG_KERNEL_UPROBE:
781 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
782 break;
783 case LTTNG_KERNEL_FUNCTION:
784 (*events)[i].type = LTTNG_EVENT_FUNCTION;
785 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
786 sizeof(struct lttng_kernel_function));
787 break;
788 case LTTNG_KERNEL_NOOP:
789 (*events)[i].type = LTTNG_EVENT_NOOP;
790 break;
791 case LTTNG_KERNEL_SYSCALL:
792 (*events)[i].type = LTTNG_EVENT_SYSCALL;
793 break;
794 case LTTNG_KERNEL_ALL:
795 /* fall-through. */
796 default:
797 assert(0);
798 break;
799 }
800 i++;
801
802 /* Append extended info */
803 ret = append_extended_info(event->filter_expression, NULL,
804 event->userspace_probe_location, &extended_at);
805 if (ret) {
806 DBG("Error appending extended info message");
807 ret = -LTTNG_ERR_FATAL;
808 goto error;
809 }
810 }
811
812 end:
813 return nb_event;
814
815 error:
816 /* Negate the error code to differentiate the size from an error */
817 return -ret;
818 }
819
820 /*
821 * Add URI so the consumer output object. Set the correct path depending on the
822 * domain adding the default trace directory.
823 */
824 static enum lttng_error_code add_uri_to_consumer(
825 const struct ltt_session *session,
826 struct consumer_output *consumer,
827 struct lttng_uri *uri, enum lttng_domain_type domain)
828 {
829 int ret;
830 enum lttng_error_code ret_code = LTTNG_OK;
831
832 assert(uri);
833
834 if (consumer == NULL) {
835 DBG("No consumer detected. Don't add URI. Stopping.");
836 ret_code = LTTNG_ERR_NO_CONSUMER;
837 goto error;
838 }
839
840 switch (domain) {
841 case LTTNG_DOMAIN_KERNEL:
842 ret = lttng_strncpy(consumer->domain_subdir,
843 DEFAULT_KERNEL_TRACE_DIR,
844 sizeof(consumer->domain_subdir));
845 break;
846 case LTTNG_DOMAIN_UST:
847 ret = lttng_strncpy(consumer->domain_subdir,
848 DEFAULT_UST_TRACE_DIR,
849 sizeof(consumer->domain_subdir));
850 break;
851 default:
852 /*
853 * This case is possible is we try to add the URI to the global
854 * tracing session consumer object which in this case there is
855 * no subdir.
856 */
857 memset(consumer->domain_subdir, 0,
858 sizeof(consumer->domain_subdir));
859 ret = 0;
860 }
861 if (ret) {
862 ERR("Failed to initialize consumer output domain subdirectory");
863 ret_code = LTTNG_ERR_FATAL;
864 goto error;
865 }
866
867 switch (uri->dtype) {
868 case LTTNG_DST_IPV4:
869 case LTTNG_DST_IPV6:
870 DBG2("Setting network URI to consumer");
871
872 if (consumer->type == CONSUMER_DST_NET) {
873 if ((uri->stype == LTTNG_STREAM_CONTROL &&
874 consumer->dst.net.control_isset) ||
875 (uri->stype == LTTNG_STREAM_DATA &&
876 consumer->dst.net.data_isset)) {
877 ret_code = LTTNG_ERR_URL_EXIST;
878 goto error;
879 }
880 } else {
881 memset(&consumer->dst, 0, sizeof(consumer->dst));
882 }
883
884 /* Set URI into consumer output object */
885 ret = consumer_set_network_uri(session, consumer, uri);
886 if (ret < 0) {
887 ret_code = -ret;
888 goto error;
889 } else if (ret == 1) {
890 /*
891 * URI was the same in the consumer so we do not append the subdir
892 * again so to not duplicate output dir.
893 */
894 ret_code = LTTNG_OK;
895 goto error;
896 }
897 break;
898 case LTTNG_DST_PATH:
899 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
900 ret_code = LTTNG_ERR_INVALID;
901 goto error;
902 }
903 DBG2("Setting trace directory path from URI to %s",
904 uri->dst.path);
905 memset(&consumer->dst, 0, sizeof(consumer->dst));
906
907 ret = lttng_strncpy(consumer->dst.session_root_path,
908 uri->dst.path,
909 sizeof(consumer->dst.session_root_path));
910 if (ret) {
911 ret_code = LTTNG_ERR_FATAL;
912 goto error;
913 }
914 consumer->type = CONSUMER_DST_LOCAL;
915 break;
916 }
917
918 ret_code = LTTNG_OK;
919 error:
920 return ret_code;
921 }
922
923 /*
924 * Init tracing by creating trace directory and sending fds kernel consumer.
925 */
926 static int init_kernel_tracing(struct ltt_kernel_session *session)
927 {
928 int ret = 0;
929 struct lttng_ht_iter iter;
930 struct consumer_socket *socket;
931
932 assert(session);
933
934 rcu_read_lock();
935
936 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
937 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
938 socket, node.node) {
939 pthread_mutex_lock(socket->lock);
940 ret = kernel_consumer_send_session(socket, session);
941 pthread_mutex_unlock(socket->lock);
942 if (ret < 0) {
943 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
944 goto error;
945 }
946 }
947 }
948
949 error:
950 rcu_read_unlock();
951 return ret;
952 }
953
954 /*
955 * Create a socket to the relayd using the URI.
956 *
957 * On success, the relayd_sock pointer is set to the created socket.
958 * Else, it remains untouched and an LTTng error code is returned.
959 */
960 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
961 struct lttcomm_relayd_sock **relayd_sock,
962 struct consumer_output *consumer)
963 {
964 int ret;
965 enum lttng_error_code status = LTTNG_OK;
966 struct lttcomm_relayd_sock *rsock;
967
968 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
969 RELAYD_VERSION_COMM_MINOR);
970 if (!rsock) {
971 status = LTTNG_ERR_FATAL;
972 goto error;
973 }
974
975 /*
976 * Connect to relayd so we can proceed with a session creation. This call
977 * can possibly block for an arbitrary amount of time to set the health
978 * state to be in poll execution.
979 */
980 health_poll_entry();
981 ret = relayd_connect(rsock);
982 health_poll_exit();
983 if (ret < 0) {
984 ERR("Unable to reach lttng-relayd");
985 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
986 goto free_sock;
987 }
988
989 /* Create socket for control stream. */
990 if (uri->stype == LTTNG_STREAM_CONTROL) {
991 uint64_t result_flags;
992
993 DBG3("Creating relayd stream socket from URI");
994
995 /* Check relayd version */
996 ret = relayd_version_check(rsock);
997 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
998 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
999 goto close_sock;
1000 } else if (ret < 0) {
1001 ERR("Unable to reach lttng-relayd");
1002 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1003 goto close_sock;
1004 }
1005 consumer->relay_major_version = rsock->major;
1006 consumer->relay_minor_version = rsock->minor;
1007 ret = relayd_get_configuration(rsock, 0,
1008 &result_flags);
1009 if (ret < 0) {
1010 ERR("Unable to get relayd configuration");
1011 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1012 goto close_sock;
1013 }
1014 if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
1015 consumer->relay_allows_clear = true;
1016 }
1017 } else if (uri->stype == LTTNG_STREAM_DATA) {
1018 DBG3("Creating relayd data socket from URI");
1019 } else {
1020 /* Command is not valid */
1021 ERR("Relayd invalid stream type: %d", uri->stype);
1022 status = LTTNG_ERR_INVALID;
1023 goto close_sock;
1024 }
1025
1026 *relayd_sock = rsock;
1027
1028 return status;
1029
1030 close_sock:
1031 /* The returned value is not useful since we are on an error path. */
1032 (void) relayd_close(rsock);
1033 free_sock:
1034 free(rsock);
1035 error:
1036 return status;
1037 }
1038
1039 /*
1040 * Connect to the relayd using URI and send the socket to the right consumer.
1041 *
1042 * The consumer socket lock must be held by the caller.
1043 *
1044 * Returns LTTNG_OK on success or an LTTng error code on failure.
1045 */
1046 static enum lttng_error_code send_consumer_relayd_socket(
1047 unsigned int session_id,
1048 struct lttng_uri *relayd_uri,
1049 struct consumer_output *consumer,
1050 struct consumer_socket *consumer_sock,
1051 const char *session_name, const char *hostname,
1052 const char *base_path, int session_live_timer,
1053 const uint64_t *current_chunk_id,
1054 time_t session_creation_time,
1055 bool session_name_contains_creation_time)
1056 {
1057 int ret;
1058 struct lttcomm_relayd_sock *rsock = NULL;
1059 enum lttng_error_code status;
1060
1061 /* Connect to relayd and make version check if uri is the control. */
1062 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1063 if (status != LTTNG_OK) {
1064 goto relayd_comm_error;
1065 }
1066 assert(rsock);
1067
1068 /* Set the network sequence index if not set. */
1069 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1070 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1071 /*
1072 * Increment net_seq_idx because we are about to transfer the
1073 * new relayd socket to the consumer.
1074 * Assign unique key so the consumer can match streams.
1075 */
1076 consumer->net_seq_index = ++relayd_net_seq_idx;
1077 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1078 }
1079
1080 /* Send relayd socket to consumer. */
1081 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1082 relayd_uri->stype, session_id,
1083 session_name, hostname, base_path,
1084 session_live_timer, current_chunk_id,
1085 session_creation_time, session_name_contains_creation_time);
1086 if (ret < 0) {
1087 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1088 goto close_sock;
1089 }
1090
1091 /* Flag that the corresponding socket was sent. */
1092 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1093 consumer_sock->control_sock_sent = 1;
1094 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1095 consumer_sock->data_sock_sent = 1;
1096 }
1097
1098 /*
1099 * Close socket which was dup on the consumer side. The session daemon does
1100 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1101 */
1102
1103 close_sock:
1104 if (status != LTTNG_OK) {
1105 /*
1106 * The consumer output for this session should not be used anymore
1107 * since the relayd connection failed thus making any tracing or/and
1108 * streaming not usable.
1109 */
1110 consumer->enabled = 0;
1111 }
1112 (void) relayd_close(rsock);
1113 free(rsock);
1114
1115 relayd_comm_error:
1116 return status;
1117 }
1118
1119 /*
1120 * Send both relayd sockets to a specific consumer and domain. This is a
1121 * helper function to facilitate sending the information to the consumer for a
1122 * session.
1123 *
1124 * The consumer socket lock must be held by the caller.
1125 *
1126 * Returns LTTNG_OK, or an LTTng error code on failure.
1127 */
1128 static enum lttng_error_code send_consumer_relayd_sockets(
1129 enum lttng_domain_type domain,
1130 unsigned int session_id, struct consumer_output *consumer,
1131 struct consumer_socket *sock, const char *session_name,
1132 const char *hostname, const char *base_path, int session_live_timer,
1133 const uint64_t *current_chunk_id, time_t session_creation_time,
1134 bool session_name_contains_creation_time)
1135 {
1136 enum lttng_error_code status = LTTNG_OK;
1137
1138 assert(consumer);
1139 assert(sock);
1140
1141 /* Sending control relayd socket. */
1142 if (!sock->control_sock_sent) {
1143 status = send_consumer_relayd_socket(session_id,
1144 &consumer->dst.net.control, consumer, sock,
1145 session_name, hostname, base_path, session_live_timer,
1146 current_chunk_id, session_creation_time,
1147 session_name_contains_creation_time);
1148 if (status != LTTNG_OK) {
1149 goto error;
1150 }
1151 }
1152
1153 /* Sending data relayd socket. */
1154 if (!sock->data_sock_sent) {
1155 status = send_consumer_relayd_socket(session_id,
1156 &consumer->dst.net.data, consumer, sock,
1157 session_name, hostname, base_path, session_live_timer,
1158 current_chunk_id, session_creation_time,
1159 session_name_contains_creation_time);
1160 if (status != LTTNG_OK) {
1161 goto error;
1162 }
1163 }
1164
1165 error:
1166 return status;
1167 }
1168
1169 /*
1170 * Setup relayd connections for a tracing session. First creates the socket to
1171 * the relayd and send them to the right domain consumer. Consumer type MUST be
1172 * network.
1173 */
1174 int cmd_setup_relayd(struct ltt_session *session)
1175 {
1176 int ret = LTTNG_OK;
1177 struct ltt_ust_session *usess;
1178 struct ltt_kernel_session *ksess;
1179 struct consumer_socket *socket;
1180 struct lttng_ht_iter iter;
1181 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1182
1183 assert(session);
1184
1185 usess = session->ust_session;
1186 ksess = session->kernel_session;
1187
1188 DBG("Setting relayd for session %s", session->name);
1189
1190 rcu_read_lock();
1191 if (session->current_trace_chunk) {
1192 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1193 session->current_trace_chunk, &current_chunk_id.value);
1194
1195 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1196 current_chunk_id.is_set = true;
1197 } else {
1198 ERR("Failed to get current trace chunk id");
1199 ret = LTTNG_ERR_UNK;
1200 goto error;
1201 }
1202 }
1203
1204 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1205 && usess->consumer->enabled) {
1206 /* For each consumer socket, send relayd sockets */
1207 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1208 socket, node.node) {
1209 pthread_mutex_lock(socket->lock);
1210 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1211 usess->consumer, socket,
1212 session->name, session->hostname,
1213 session->base_path,
1214 session->live_timer,
1215 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1216 session->creation_time,
1217 session->name_contains_creation_time);
1218 pthread_mutex_unlock(socket->lock);
1219 if (ret != LTTNG_OK) {
1220 goto error;
1221 }
1222 /* Session is now ready for network streaming. */
1223 session->net_handle = 1;
1224 }
1225 session->consumer->relay_major_version =
1226 usess->consumer->relay_major_version;
1227 session->consumer->relay_minor_version =
1228 usess->consumer->relay_minor_version;
1229 session->consumer->relay_allows_clear =
1230 usess->consumer->relay_allows_clear;
1231 }
1232
1233 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1234 && ksess->consumer->enabled) {
1235 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1236 socket, node.node) {
1237 pthread_mutex_lock(socket->lock);
1238 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1239 ksess->consumer, socket,
1240 session->name, session->hostname,
1241 session->base_path,
1242 session->live_timer,
1243 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1244 session->creation_time,
1245 session->name_contains_creation_time);
1246 pthread_mutex_unlock(socket->lock);
1247 if (ret != LTTNG_OK) {
1248 goto error;
1249 }
1250 /* Session is now ready for network streaming. */
1251 session->net_handle = 1;
1252 }
1253 session->consumer->relay_major_version =
1254 ksess->consumer->relay_major_version;
1255 session->consumer->relay_minor_version =
1256 ksess->consumer->relay_minor_version;
1257 session->consumer->relay_allows_clear =
1258 ksess->consumer->relay_allows_clear;
1259 }
1260
1261 error:
1262 rcu_read_unlock();
1263 return ret;
1264 }
1265
1266 /*
1267 * Start a kernel session by opening all necessary streams.
1268 */
1269 int start_kernel_session(struct ltt_kernel_session *ksess)
1270 {
1271 int ret;
1272 struct ltt_kernel_channel *kchan;
1273
1274 /* Open kernel metadata */
1275 if (ksess->metadata == NULL && ksess->output_traces) {
1276 ret = kernel_open_metadata(ksess);
1277 if (ret < 0) {
1278 ret = LTTNG_ERR_KERN_META_FAIL;
1279 goto error;
1280 }
1281 }
1282
1283 /* Open kernel metadata stream */
1284 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1285 ret = kernel_open_metadata_stream(ksess);
1286 if (ret < 0) {
1287 ERR("Kernel create metadata stream failed");
1288 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1289 goto error;
1290 }
1291 }
1292
1293 /* For each channel */
1294 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1295 if (kchan->stream_count == 0) {
1296 ret = kernel_open_channel_stream(kchan);
1297 if (ret < 0) {
1298 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1299 goto error;
1300 }
1301 /* Update the stream global counter */
1302 ksess->stream_count_global += ret;
1303 }
1304 }
1305
1306 /* Setup kernel consumer socket and send fds to it */
1307 ret = init_kernel_tracing(ksess);
1308 if (ret != 0) {
1309 ret = LTTNG_ERR_KERN_START_FAIL;
1310 goto error;
1311 }
1312
1313 /* This start the kernel tracing */
1314 ret = kernel_start_session(ksess);
1315 if (ret < 0) {
1316 ret = LTTNG_ERR_KERN_START_FAIL;
1317 goto error;
1318 }
1319
1320 /* Quiescent wait after starting trace */
1321 kernel_wait_quiescent();
1322
1323 ksess->active = 1;
1324
1325 ret = LTTNG_OK;
1326
1327 error:
1328 return ret;
1329 }
1330
1331 int stop_kernel_session(struct ltt_kernel_session *ksess)
1332 {
1333 struct ltt_kernel_channel *kchan;
1334 bool error_occurred = false;
1335 int ret;
1336
1337 if (!ksess || !ksess->active) {
1338 return LTTNG_OK;
1339 }
1340 DBG("Stopping kernel tracing");
1341
1342 ret = kernel_stop_session(ksess);
1343 if (ret < 0) {
1344 ret = LTTNG_ERR_KERN_STOP_FAIL;
1345 goto error;
1346 }
1347
1348 kernel_wait_quiescent();
1349
1350 /* Flush metadata after stopping (if exists) */
1351 if (ksess->metadata_stream_fd >= 0) {
1352 ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
1353 if (ret < 0) {
1354 ERR("Kernel metadata flush failed");
1355 error_occurred = true;
1356 }
1357 }
1358
1359 /* Flush all buffers after stopping */
1360 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1361 ret = kernel_flush_buffer(kchan);
1362 if (ret < 0) {
1363 ERR("Kernel flush buffer error");
1364 error_occurred = true;
1365 }
1366 }
1367
1368 ksess->active = 0;
1369 if (error_occurred) {
1370 ret = LTTNG_ERR_UNK;
1371 } else {
1372 ret = LTTNG_OK;
1373 }
1374 error:
1375 return ret;
1376 }
1377
1378 /*
1379 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1380 */
1381 int cmd_disable_channel(struct ltt_session *session,
1382 enum lttng_domain_type domain, char *channel_name)
1383 {
1384 int ret;
1385 struct ltt_ust_session *usess;
1386
1387 usess = session->ust_session;
1388
1389 rcu_read_lock();
1390
1391 switch (domain) {
1392 case LTTNG_DOMAIN_KERNEL:
1393 {
1394 ret = channel_kernel_disable(session->kernel_session,
1395 channel_name);
1396 if (ret != LTTNG_OK) {
1397 goto error;
1398 }
1399
1400 kernel_wait_quiescent();
1401 break;
1402 }
1403 case LTTNG_DOMAIN_UST:
1404 {
1405 struct ltt_ust_channel *uchan;
1406 struct lttng_ht *chan_ht;
1407
1408 chan_ht = usess->domain_global.channels;
1409
1410 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1411 if (uchan == NULL) {
1412 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1413 goto error;
1414 }
1415
1416 ret = channel_ust_disable(usess, uchan);
1417 if (ret != LTTNG_OK) {
1418 goto error;
1419 }
1420 break;
1421 }
1422 default:
1423 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1424 goto error;
1425 }
1426
1427 ret = LTTNG_OK;
1428
1429 error:
1430 rcu_read_unlock();
1431 return ret;
1432 }
1433
1434 /*
1435 * Command LTTNG_TRACK_ID processed by the client thread.
1436 *
1437 * Called with session lock held.
1438 */
1439 int cmd_track_id(struct ltt_session *session,
1440 enum lttng_tracker_type tracker_type,
1441 enum lttng_domain_type domain,
1442 const struct lttng_tracker_id *id)
1443 {
1444 int ret;
1445
1446 rcu_read_lock();
1447
1448 switch (domain) {
1449 case LTTNG_DOMAIN_KERNEL:
1450 {
1451 struct ltt_kernel_session *ksess;
1452
1453 ksess = session->kernel_session;
1454
1455 ret = kernel_track_id(tracker_type, ksess, id);
1456 if (ret != LTTNG_OK) {
1457 goto error;
1458 }
1459
1460 kernel_wait_quiescent();
1461 break;
1462 }
1463 case LTTNG_DOMAIN_UST:
1464 {
1465 struct ltt_ust_session *usess;
1466
1467 usess = session->ust_session;
1468
1469 ret = trace_ust_track_id(tracker_type, usess, id);
1470 if (ret != LTTNG_OK) {
1471 goto error;
1472 }
1473 break;
1474 }
1475 default:
1476 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1477 goto error;
1478 }
1479
1480 ret = LTTNG_OK;
1481
1482 error:
1483 rcu_read_unlock();
1484 return ret;
1485 }
1486
1487 /*
1488 * Command LTTNG_UNTRACK_ID processed by the client thread.
1489 *
1490 * Called with session lock held.
1491 */
1492 int cmd_untrack_id(struct ltt_session *session,
1493 enum lttng_tracker_type tracker_type,
1494 enum lttng_domain_type domain,
1495 const struct lttng_tracker_id *id)
1496 {
1497 int ret;
1498
1499 rcu_read_lock();
1500
1501 switch (domain) {
1502 case LTTNG_DOMAIN_KERNEL:
1503 {
1504 struct ltt_kernel_session *ksess;
1505
1506 ksess = session->kernel_session;
1507
1508 ret = kernel_untrack_id(tracker_type, ksess, id);
1509 if (ret != LTTNG_OK) {
1510 goto error;
1511 }
1512
1513 kernel_wait_quiescent();
1514 break;
1515 }
1516 case LTTNG_DOMAIN_UST:
1517 {
1518 struct ltt_ust_session *usess;
1519
1520 usess = session->ust_session;
1521
1522 ret = trace_ust_untrack_id(tracker_type, usess, id);
1523 if (ret != LTTNG_OK) {
1524 goto error;
1525 }
1526 break;
1527 }
1528 default:
1529 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1530 goto error;
1531 }
1532
1533 ret = LTTNG_OK;
1534
1535 error:
1536 rcu_read_unlock();
1537 return ret;
1538 }
1539
1540 /*
1541 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1542 *
1543 * The wpipe arguments is used as a notifier for the kernel thread.
1544 */
1545 int cmd_enable_channel(struct ltt_session *session,
1546 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1547 {
1548 int ret;
1549 struct ltt_ust_session *usess = session->ust_session;
1550 struct lttng_ht *chan_ht;
1551 size_t len;
1552 struct lttng_channel attr;
1553
1554 assert(session);
1555 assert(_attr);
1556 assert(domain);
1557
1558 attr = *_attr;
1559 len = lttng_strnlen(attr.name, sizeof(attr.name));
1560
1561 /* Validate channel name */
1562 if (attr.name[0] == '.' ||
1563 memchr(attr.name, '/', len) != NULL) {
1564 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1565 goto end;
1566 }
1567
1568 DBG("Enabling channel %s for session %s", attr.name, session->name);
1569
1570 rcu_read_lock();
1571
1572 /*
1573 * Don't try to enable a channel if the session has been started at
1574 * some point in time before. The tracer does not allow it.
1575 */
1576 if (session->has_been_started) {
1577 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1578 goto error;
1579 }
1580
1581 /*
1582 * If the session is a live session, remove the switch timer, the
1583 * live timer does the same thing but sends also synchronisation
1584 * beacons for inactive streams.
1585 */
1586 if (session->live_timer > 0) {
1587 attr.attr.live_timer_interval = session->live_timer;
1588 attr.attr.switch_timer_interval = 0;
1589 }
1590
1591 /* Check for feature support */
1592 switch (domain->type) {
1593 case LTTNG_DOMAIN_KERNEL:
1594 {
1595 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1596 /* Sampling position of buffer is not supported */
1597 WARN("Kernel tracer does not support buffer monitoring. "
1598 "Setting the monitor interval timer to 0 "
1599 "(disabled) for channel '%s' of session '%s'",
1600 attr.name, session->name);
1601 lttng_channel_set_monitor_timer_interval(&attr, 0);
1602 }
1603 break;
1604 }
1605 case LTTNG_DOMAIN_UST:
1606 break;
1607 case LTTNG_DOMAIN_JUL:
1608 case LTTNG_DOMAIN_LOG4J:
1609 case LTTNG_DOMAIN_PYTHON:
1610 if (!agent_tracing_is_enabled()) {
1611 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1612 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1613 goto error;
1614 }
1615 break;
1616 default:
1617 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1618 goto error;
1619 }
1620
1621 switch (domain->type) {
1622 case LTTNG_DOMAIN_KERNEL:
1623 {
1624 struct ltt_kernel_channel *kchan;
1625
1626 kchan = trace_kernel_get_channel_by_name(attr.name,
1627 session->kernel_session);
1628 if (kchan == NULL) {
1629 if (session->snapshot.nb_output > 0 ||
1630 session->snapshot_mode) {
1631 /* Enforce mmap output for snapshot sessions. */
1632 attr.attr.output = LTTNG_EVENT_MMAP;
1633 }
1634 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1635 if (attr.name[0] != '\0') {
1636 session->kernel_session->has_non_default_channel = 1;
1637 }
1638 } else {
1639 ret = channel_kernel_enable(session->kernel_session, kchan);
1640 }
1641
1642 if (ret != LTTNG_OK) {
1643 goto error;
1644 }
1645
1646 kernel_wait_quiescent();
1647 break;
1648 }
1649 case LTTNG_DOMAIN_UST:
1650 case LTTNG_DOMAIN_JUL:
1651 case LTTNG_DOMAIN_LOG4J:
1652 case LTTNG_DOMAIN_PYTHON:
1653 {
1654 struct ltt_ust_channel *uchan;
1655
1656 /*
1657 * FIXME
1658 *
1659 * Current agent implementation limitations force us to allow
1660 * only one channel at once in "agent" subdomains. Each
1661 * subdomain has a default channel name which must be strictly
1662 * adhered to.
1663 */
1664 if (domain->type == LTTNG_DOMAIN_JUL) {
1665 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1666 LTTNG_SYMBOL_NAME_LEN)) {
1667 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1668 goto error;
1669 }
1670 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1671 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1672 LTTNG_SYMBOL_NAME_LEN)) {
1673 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1674 goto error;
1675 }
1676 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1677 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1678 LTTNG_SYMBOL_NAME_LEN)) {
1679 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1680 goto error;
1681 }
1682 }
1683
1684 chan_ht = usess->domain_global.channels;
1685
1686 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1687 if (uchan == NULL) {
1688 ret = channel_ust_create(usess, &attr, domain->buf_type);
1689 if (attr.name[0] != '\0') {
1690 usess->has_non_default_channel = 1;
1691 }
1692 } else {
1693 ret = channel_ust_enable(usess, uchan);
1694 }
1695 break;
1696 }
1697 default:
1698 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1699 goto error;
1700 }
1701
1702 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1703 session->has_non_mmap_channel = true;
1704 }
1705 error:
1706 rcu_read_unlock();
1707 end:
1708 return ret;
1709 }
1710
1711 /*
1712 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1713 */
1714 int cmd_disable_event(struct ltt_session *session,
1715 enum lttng_domain_type domain, const char *channel_name,
1716 const struct lttng_event *event)
1717 {
1718 int ret;
1719 const char *event_name;
1720
1721 DBG("Disable event command for event \'%s\'", event->name);
1722
1723 event_name = event->name;
1724
1725 /* Error out on unhandled search criteria */
1726 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1727 || event->pid || event->filter || event->exclusion) {
1728 ret = LTTNG_ERR_UNK;
1729 goto error;
1730 }
1731
1732 rcu_read_lock();
1733
1734 switch (domain) {
1735 case LTTNG_DOMAIN_KERNEL:
1736 {
1737 struct ltt_kernel_channel *kchan;
1738 struct ltt_kernel_session *ksess;
1739
1740 ksess = session->kernel_session;
1741
1742 /*
1743 * If a non-default channel has been created in the
1744 * session, explicitely require that -c chan_name needs
1745 * to be provided.
1746 */
1747 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1748 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1749 goto error_unlock;
1750 }
1751
1752 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1753 if (kchan == NULL) {
1754 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1755 goto error_unlock;
1756 }
1757
1758 switch (event->type) {
1759 case LTTNG_EVENT_ALL:
1760 case LTTNG_EVENT_TRACEPOINT:
1761 case LTTNG_EVENT_SYSCALL:
1762 case LTTNG_EVENT_PROBE:
1763 case LTTNG_EVENT_FUNCTION:
1764 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1765 if (event_name[0] == '\0') {
1766 ret = event_kernel_disable_event(kchan,
1767 NULL, event->type);
1768 } else {
1769 ret = event_kernel_disable_event(kchan,
1770 event_name, event->type);
1771 }
1772 if (ret != LTTNG_OK) {
1773 goto error_unlock;
1774 }
1775 break;
1776 default:
1777 ret = LTTNG_ERR_UNK;
1778 goto error_unlock;
1779 }
1780
1781 kernel_wait_quiescent();
1782 break;
1783 }
1784 case LTTNG_DOMAIN_UST:
1785 {
1786 struct ltt_ust_channel *uchan;
1787 struct ltt_ust_session *usess;
1788
1789 usess = session->ust_session;
1790
1791 if (validate_ust_event_name(event_name)) {
1792 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1793 goto error_unlock;
1794 }
1795
1796 /*
1797 * If a non-default channel has been created in the
1798 * session, explicitly require that -c chan_name needs
1799 * to be provided.
1800 */
1801 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1802 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1803 goto error_unlock;
1804 }
1805
1806 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1807 channel_name);
1808 if (uchan == NULL) {
1809 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1810 goto error_unlock;
1811 }
1812
1813 switch (event->type) {
1814 case LTTNG_EVENT_ALL:
1815 /*
1816 * An empty event name means that everything
1817 * should be disabled.
1818 */
1819 if (event->name[0] == '\0') {
1820 ret = event_ust_disable_all_tracepoints(usess, uchan);
1821 } else {
1822 ret = event_ust_disable_tracepoint(usess, uchan,
1823 event_name);
1824 }
1825 if (ret != LTTNG_OK) {
1826 goto error_unlock;
1827 }
1828 break;
1829 default:
1830 ret = LTTNG_ERR_UNK;
1831 goto error_unlock;
1832 }
1833
1834 DBG3("Disable UST event %s in channel %s completed", event_name,
1835 channel_name);
1836 break;
1837 }
1838 case LTTNG_DOMAIN_LOG4J:
1839 case LTTNG_DOMAIN_JUL:
1840 case LTTNG_DOMAIN_PYTHON:
1841 {
1842 struct agent *agt;
1843 struct ltt_ust_session *usess = session->ust_session;
1844
1845 assert(usess);
1846
1847 switch (event->type) {
1848 case LTTNG_EVENT_ALL:
1849 break;
1850 default:
1851 ret = LTTNG_ERR_UNK;
1852 goto error_unlock;
1853 }
1854
1855 agt = trace_ust_find_agent(usess, domain);
1856 if (!agt) {
1857 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1858 goto error_unlock;
1859 }
1860 /*
1861 * An empty event name means that everything
1862 * should be disabled.
1863 */
1864 if (event->name[0] == '\0') {
1865 ret = event_agent_disable_all(usess, agt);
1866 } else {
1867 ret = event_agent_disable(usess, agt, event_name);
1868 }
1869 if (ret != LTTNG_OK) {
1870 goto error_unlock;
1871 }
1872
1873 break;
1874 }
1875 default:
1876 ret = LTTNG_ERR_UND;
1877 goto error_unlock;
1878 }
1879
1880 ret = LTTNG_OK;
1881
1882 error_unlock:
1883 rcu_read_unlock();
1884 error:
1885 return ret;
1886 }
1887
1888 /*
1889 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1890 */
1891 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1892 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1893 {
1894 int ret, chan_kern_created = 0, chan_ust_created = 0;
1895 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1896
1897 /*
1898 * Don't try to add a context if the session has been started at
1899 * some point in time before. The tracer does not allow it and would
1900 * result in a corrupted trace.
1901 */
1902 if (session->has_been_started) {
1903 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1904 goto end;
1905 }
1906
1907 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1908 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1909 app_ctx_name = ctx->u.app_ctx.ctx_name;
1910 }
1911
1912 switch (domain) {
1913 case LTTNG_DOMAIN_KERNEL:
1914 assert(session->kernel_session);
1915
1916 if (session->kernel_session->channel_count == 0) {
1917 /* Create default channel */
1918 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1919 if (ret != LTTNG_OK) {
1920 goto error;
1921 }
1922 chan_kern_created = 1;
1923 }
1924 /* Add kernel context to kernel tracer */
1925 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1926 if (ret != LTTNG_OK) {
1927 goto error;
1928 }
1929 break;
1930 case LTTNG_DOMAIN_JUL:
1931 case LTTNG_DOMAIN_LOG4J:
1932 {
1933 /*
1934 * Validate channel name.
1935 * If no channel name is given and the domain is JUL or LOG4J,
1936 * set it to the appropriate domain-specific channel name. If
1937 * a name is provided but does not match the expexted channel
1938 * name, return an error.
1939 */
1940 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1941 strcmp(channel_name,
1942 DEFAULT_JUL_CHANNEL_NAME)) {
1943 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1944 goto error;
1945 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1946 strcmp(channel_name,
1947 DEFAULT_LOG4J_CHANNEL_NAME)) {
1948 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1949 goto error;
1950 }
1951 /* break is _not_ missing here. */
1952 }
1953 case LTTNG_DOMAIN_UST:
1954 {
1955 struct ltt_ust_session *usess = session->ust_session;
1956 unsigned int chan_count;
1957
1958 assert(usess);
1959
1960 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1961 if (chan_count == 0) {
1962 struct lttng_channel *attr;
1963 /* Create default channel */
1964 attr = channel_new_default_attr(domain, usess->buffer_type);
1965 if (attr == NULL) {
1966 ret = LTTNG_ERR_FATAL;
1967 goto error;
1968 }
1969
1970 ret = channel_ust_create(usess, attr, usess->buffer_type);
1971 if (ret != LTTNG_OK) {
1972 free(attr);
1973 goto error;
1974 }
1975 channel_attr_destroy(attr);
1976 chan_ust_created = 1;
1977 }
1978
1979 ret = context_ust_add(usess, domain, ctx, channel_name);
1980 free(app_ctx_provider_name);
1981 free(app_ctx_name);
1982 app_ctx_name = NULL;
1983 app_ctx_provider_name = NULL;
1984 if (ret != LTTNG_OK) {
1985 goto error;
1986 }
1987 break;
1988 }
1989 default:
1990 ret = LTTNG_ERR_UND;
1991 goto error;
1992 }
1993
1994 ret = LTTNG_OK;
1995 goto end;
1996
1997 error:
1998 if (chan_kern_created) {
1999 struct ltt_kernel_channel *kchan =
2000 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
2001 session->kernel_session);
2002 /* Created previously, this should NOT fail. */
2003 assert(kchan);
2004 kernel_destroy_channel(kchan);
2005 }
2006
2007 if (chan_ust_created) {
2008 struct ltt_ust_channel *uchan =
2009 trace_ust_find_channel_by_name(
2010 session->ust_session->domain_global.channels,
2011 DEFAULT_CHANNEL_NAME);
2012 /* Created previously, this should NOT fail. */
2013 assert(uchan);
2014 /* Remove from the channel list of the session. */
2015 trace_ust_delete_channel(session->ust_session->domain_global.channels,
2016 uchan);
2017 trace_ust_destroy_channel(uchan);
2018 }
2019 end:
2020 free(app_ctx_provider_name);
2021 free(app_ctx_name);
2022 return ret;
2023 }
2024
2025 static inline bool name_starts_with(const char *name, const char *prefix)
2026 {
2027 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
2028
2029 return !strncmp(name, prefix, max_cmp_len);
2030 }
2031
2032 /* Perform userspace-specific event name validation */
2033 static int validate_ust_event_name(const char *name)
2034 {
2035 int ret = 0;
2036
2037 if (!name) {
2038 ret = -1;
2039 goto end;
2040 }
2041
2042 /*
2043 * Check name against all internal UST event component namespaces used
2044 * by the agents.
2045 */
2046 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
2047 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
2048 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
2049 ret = -1;
2050 }
2051
2052 end:
2053 return ret;
2054 }
2055
2056 /*
2057 * Internal version of cmd_enable_event() with a supplemental
2058 * "internal_event" flag which is used to enable internal events which should
2059 * be hidden from clients. Such events are used in the agent implementation to
2060 * enable the events through which all "agent" events are funeled.
2061 */
2062 static int _cmd_enable_event(struct ltt_session *session,
2063 const struct lttng_domain *domain,
2064 char *channel_name, struct lttng_event *event,
2065 char *filter_expression,
2066 struct lttng_filter_bytecode *filter,
2067 struct lttng_event_exclusion *exclusion,
2068 int wpipe, bool internal_event)
2069 {
2070 int ret = 0, channel_created = 0;
2071 struct lttng_channel *attr = NULL;
2072
2073 assert(session);
2074 assert(event);
2075 assert(channel_name);
2076
2077 /* If we have a filter, we must have its filter expression */
2078 assert(!(!!filter_expression ^ !!filter));
2079
2080 /* Normalize event name as a globbing pattern */
2081 strutils_normalize_star_glob_pattern(event->name);
2082
2083 /* Normalize exclusion names as globbing patterns */
2084 if (exclusion) {
2085 size_t i;
2086
2087 for (i = 0; i < exclusion->count; i++) {
2088 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2089
2090 strutils_normalize_star_glob_pattern(name);
2091 }
2092 }
2093
2094 DBG("Enable event command for event \'%s\'", event->name);
2095
2096 rcu_read_lock();
2097
2098 switch (domain->type) {
2099 case LTTNG_DOMAIN_KERNEL:
2100 {
2101 struct ltt_kernel_channel *kchan;
2102
2103 /*
2104 * If a non-default channel has been created in the
2105 * session, explicitely require that -c chan_name needs
2106 * to be provided.
2107 */
2108 if (session->kernel_session->has_non_default_channel
2109 && channel_name[0] == '\0') {
2110 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2111 goto error;
2112 }
2113
2114 kchan = trace_kernel_get_channel_by_name(channel_name,
2115 session->kernel_session);
2116 if (kchan == NULL) {
2117 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2118 LTTNG_BUFFER_GLOBAL);
2119 if (attr == NULL) {
2120 ret = LTTNG_ERR_FATAL;
2121 goto error;
2122 }
2123 if (lttng_strncpy(attr->name, channel_name,
2124 sizeof(attr->name))) {
2125 ret = LTTNG_ERR_INVALID;
2126 goto error;
2127 }
2128
2129 ret = cmd_enable_channel(session, domain, attr, wpipe);
2130 if (ret != LTTNG_OK) {
2131 goto error;
2132 }
2133 channel_created = 1;
2134 }
2135
2136 /* Get the newly created kernel channel pointer */
2137 kchan = trace_kernel_get_channel_by_name(channel_name,
2138 session->kernel_session);
2139 if (kchan == NULL) {
2140 /* This sould not happen... */
2141 ret = LTTNG_ERR_FATAL;
2142 goto error;
2143 }
2144
2145 switch (event->type) {
2146 case LTTNG_EVENT_ALL:
2147 {
2148 char *filter_expression_a = NULL;
2149 struct lttng_filter_bytecode *filter_a = NULL;
2150
2151 /*
2152 * We need to duplicate filter_expression and filter,
2153 * because ownership is passed to first enable
2154 * event.
2155 */
2156 if (filter_expression) {
2157 filter_expression_a = strdup(filter_expression);
2158 if (!filter_expression_a) {
2159 ret = LTTNG_ERR_FATAL;
2160 goto error;
2161 }
2162 }
2163 if (filter) {
2164 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2165 if (!filter_a) {
2166 free(filter_expression_a);
2167 ret = LTTNG_ERR_FATAL;
2168 goto error;
2169 }
2170 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2171 }
2172 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2173 ret = event_kernel_enable_event(kchan, event,
2174 filter_expression, filter);
2175 /* We have passed ownership */
2176 filter_expression = NULL;
2177 filter = NULL;
2178 if (ret != LTTNG_OK) {
2179 if (channel_created) {
2180 /* Let's not leak a useless channel. */
2181 kernel_destroy_channel(kchan);
2182 }
2183 free(filter_expression_a);
2184 free(filter_a);
2185 goto error;
2186 }
2187 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2188 ret = event_kernel_enable_event(kchan, event,
2189 filter_expression_a, filter_a);
2190 /* We have passed ownership */
2191 filter_expression_a = NULL;
2192 filter_a = NULL;
2193 if (ret != LTTNG_OK) {
2194 goto error;
2195 }
2196 break;
2197 }
2198 case LTTNG_EVENT_PROBE:
2199 case LTTNG_EVENT_USERSPACE_PROBE:
2200 case LTTNG_EVENT_FUNCTION:
2201 case LTTNG_EVENT_FUNCTION_ENTRY:
2202 case LTTNG_EVENT_TRACEPOINT:
2203 ret = event_kernel_enable_event(kchan, event,
2204 filter_expression, filter);
2205 /* We have passed ownership */
2206 filter_expression = NULL;
2207 filter = NULL;
2208 if (ret != LTTNG_OK) {
2209 if (channel_created) {
2210 /* Let's not leak a useless channel. */
2211 kernel_destroy_channel(kchan);
2212 }
2213 goto error;
2214 }
2215 break;
2216 case LTTNG_EVENT_SYSCALL:
2217 ret = event_kernel_enable_event(kchan, event,
2218 filter_expression, filter);
2219 /* We have passed ownership */
2220 filter_expression = NULL;
2221 filter = NULL;
2222 if (ret != LTTNG_OK) {
2223 goto error;
2224 }
2225 break;
2226 default:
2227 ret = LTTNG_ERR_UNK;
2228 goto error;
2229 }
2230
2231 kernel_wait_quiescent();
2232 break;
2233 }
2234 case LTTNG_DOMAIN_UST:
2235 {
2236 struct ltt_ust_channel *uchan;
2237 struct ltt_ust_session *usess = session->ust_session;
2238
2239 assert(usess);
2240
2241 /*
2242 * If a non-default channel has been created in the
2243 * session, explicitely require that -c chan_name needs
2244 * to be provided.
2245 */
2246 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2247 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2248 goto error;
2249 }
2250
2251 /* Get channel from global UST domain */
2252 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2253 channel_name);
2254 if (uchan == NULL) {
2255 /* Create default channel */
2256 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2257 usess->buffer_type);
2258 if (attr == NULL) {
2259 ret = LTTNG_ERR_FATAL;
2260 goto error;
2261 }
2262 if (lttng_strncpy(attr->name, channel_name,
2263 sizeof(attr->name))) {
2264 ret = LTTNG_ERR_INVALID;
2265 goto error;
2266 }
2267
2268 ret = cmd_enable_channel(session, domain, attr, wpipe);
2269 if (ret != LTTNG_OK) {
2270 goto error;
2271 }
2272
2273 /* Get the newly created channel reference back */
2274 uchan = trace_ust_find_channel_by_name(
2275 usess->domain_global.channels, channel_name);
2276 assert(uchan);
2277 }
2278
2279 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2280 /*
2281 * Don't allow users to add UST events to channels which
2282 * are assigned to a userspace subdomain (JUL, Log4J,
2283 * Python, etc.).
2284 */
2285 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2286 goto error;
2287 }
2288
2289 if (!internal_event) {
2290 /*
2291 * Ensure the event name is not reserved for internal
2292 * use.
2293 */
2294 ret = validate_ust_event_name(event->name);
2295 if (ret) {
2296 WARN("Userspace event name %s failed validation.",
2297 event->name);
2298 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2299 goto error;
2300 }
2301 }
2302
2303 /* At this point, the session and channel exist on the tracer */
2304 ret = event_ust_enable_tracepoint(usess, uchan, event,
2305 filter_expression, filter, exclusion,
2306 internal_event);
2307 /* We have passed ownership */
2308 filter_expression = NULL;
2309 filter = NULL;
2310 exclusion = NULL;
2311 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2312 goto already_enabled;
2313 } else if (ret != LTTNG_OK) {
2314 goto error;
2315 }
2316 break;
2317 }
2318 case LTTNG_DOMAIN_LOG4J:
2319 case LTTNG_DOMAIN_JUL:
2320 case LTTNG_DOMAIN_PYTHON:
2321 {
2322 const char *default_event_name, *default_chan_name;
2323 struct agent *agt;
2324 struct lttng_event uevent;
2325 struct lttng_domain tmp_dom;
2326 struct ltt_ust_session *usess = session->ust_session;
2327
2328 assert(usess);
2329
2330 if (!agent_tracing_is_enabled()) {
2331 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2332 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2333 goto error;
2334 }
2335
2336 agt = trace_ust_find_agent(usess, domain->type);
2337 if (!agt) {
2338 agt = agent_create(domain->type);
2339 if (!agt) {
2340 ret = LTTNG_ERR_NOMEM;
2341 goto error;
2342 }
2343 agent_add(agt, usess->agents);
2344 }
2345
2346 /* Create the default tracepoint. */
2347 memset(&uevent, 0, sizeof(uevent));
2348 uevent.type = LTTNG_EVENT_TRACEPOINT;
2349 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2350 default_event_name = event_get_default_agent_ust_name(
2351 domain->type);
2352 if (!default_event_name) {
2353 ret = LTTNG_ERR_FATAL;
2354 goto error;
2355 }
2356 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2357 uevent.name[sizeof(uevent.name) - 1] = '\0';
2358
2359 /*
2360 * The domain type is changed because we are about to enable the
2361 * default channel and event for the JUL domain that are hardcoded.
2362 * This happens in the UST domain.
2363 */
2364 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2365 tmp_dom.type = LTTNG_DOMAIN_UST;
2366
2367 switch (domain->type) {
2368 case LTTNG_DOMAIN_LOG4J:
2369 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2370 break;
2371 case LTTNG_DOMAIN_JUL:
2372 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2373 break;
2374 case LTTNG_DOMAIN_PYTHON:
2375 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2376 break;
2377 default:
2378 /* The switch/case we are in makes this impossible */
2379 assert(0);
2380 }
2381
2382 {
2383 char *filter_expression_copy = NULL;
2384 struct lttng_filter_bytecode *filter_copy = NULL;
2385
2386 if (filter) {
2387 const size_t filter_size = sizeof(
2388 struct lttng_filter_bytecode)
2389 + filter->len;
2390
2391 filter_copy = zmalloc(filter_size);
2392 if (!filter_copy) {
2393 ret = LTTNG_ERR_NOMEM;
2394 goto error;
2395 }
2396 memcpy(filter_copy, filter, filter_size);
2397
2398 filter_expression_copy =
2399 strdup(filter_expression);
2400 if (!filter_expression) {
2401 ret = LTTNG_ERR_NOMEM;
2402 }
2403
2404 if (!filter_expression_copy || !filter_copy) {
2405 free(filter_expression_copy);
2406 free(filter_copy);
2407 goto error;
2408 }
2409 }
2410
2411 ret = cmd_enable_event_internal(session, &tmp_dom,
2412 (char *) default_chan_name,
2413 &uevent, filter_expression_copy,
2414 filter_copy, NULL, wpipe);
2415 }
2416
2417 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2418 goto already_enabled;
2419 } else if (ret != LTTNG_OK) {
2420 goto error;
2421 }
2422
2423 /* The wild card * means that everything should be enabled. */
2424 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2425 ret = event_agent_enable_all(usess, agt, event, filter,
2426 filter_expression);
2427 } else {
2428 ret = event_agent_enable(usess, agt, event, filter,
2429 filter_expression);
2430 }
2431 filter = NULL;
2432 filter_expression = NULL;
2433 if (ret != LTTNG_OK) {
2434 goto error;
2435 }
2436
2437 break;
2438 }
2439 default:
2440 ret = LTTNG_ERR_UND;
2441 goto error;
2442 }
2443
2444 ret = LTTNG_OK;
2445
2446 already_enabled:
2447 error:
2448 free(filter_expression);
2449 free(filter);
2450 free(exclusion);
2451 channel_attr_destroy(attr);
2452 rcu_read_unlock();
2453 return ret;
2454 }
2455
2456 /*
2457 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2458 * We own filter, exclusion, and filter_expression.
2459 */
2460 int cmd_enable_event(struct ltt_session *session,
2461 const struct lttng_domain *domain,
2462 char *channel_name, struct lttng_event *event,
2463 char *filter_expression,
2464 struct lttng_filter_bytecode *filter,
2465 struct lttng_event_exclusion *exclusion,
2466 int wpipe)
2467 {
2468 return _cmd_enable_event(session, domain, channel_name, event,
2469 filter_expression, filter, exclusion, wpipe, false);
2470 }
2471
2472 /*
2473 * Enable an event which is internal to LTTng. An internal should
2474 * never be made visible to clients and are immune to checks such as
2475 * reserved names.
2476 */
2477 static int cmd_enable_event_internal(struct ltt_session *session,
2478 const struct lttng_domain *domain,
2479 char *channel_name, struct lttng_event *event,
2480 char *filter_expression,
2481 struct lttng_filter_bytecode *filter,
2482 struct lttng_event_exclusion *exclusion,
2483 int wpipe)
2484 {
2485 return _cmd_enable_event(session, domain, channel_name, event,
2486 filter_expression, filter, exclusion, wpipe, true);
2487 }
2488
2489 /*
2490 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2491 */
2492 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2493 struct lttng_event **events)
2494 {
2495 int ret;
2496 ssize_t nb_events = 0;
2497
2498 switch (domain) {
2499 case LTTNG_DOMAIN_KERNEL:
2500 nb_events = kernel_list_events(events);
2501 if (nb_events < 0) {
2502 ret = LTTNG_ERR_KERN_LIST_FAIL;
2503 goto error;
2504 }
2505 break;
2506 case LTTNG_DOMAIN_UST:
2507 nb_events = ust_app_list_events(events);
2508 if (nb_events < 0) {
2509 ret = LTTNG_ERR_UST_LIST_FAIL;
2510 goto error;
2511 }
2512 break;
2513 case LTTNG_DOMAIN_LOG4J:
2514 case LTTNG_DOMAIN_JUL:
2515 case LTTNG_DOMAIN_PYTHON:
2516 nb_events = agent_list_events(events, domain);
2517 if (nb_events < 0) {
2518 ret = LTTNG_ERR_UST_LIST_FAIL;
2519 goto error;
2520 }
2521 break;
2522 default:
2523 ret = LTTNG_ERR_UND;
2524 goto error;
2525 }
2526
2527 return nb_events;
2528
2529 error:
2530 /* Return negative value to differentiate return code */
2531 return -ret;
2532 }
2533
2534 /*
2535 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2536 */
2537 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2538 struct lttng_event_field **fields)
2539 {
2540 int ret;
2541 ssize_t nb_fields = 0;
2542
2543 switch (domain) {
2544 case LTTNG_DOMAIN_UST:
2545 nb_fields = ust_app_list_event_fields(fields);
2546 if (nb_fields < 0) {
2547 ret = LTTNG_ERR_UST_LIST_FAIL;
2548 goto error;
2549 }
2550 break;
2551 case LTTNG_DOMAIN_KERNEL:
2552 default: /* fall-through */
2553 ret = LTTNG_ERR_UND;
2554 goto error;
2555 }
2556
2557 return nb_fields;
2558
2559 error:
2560 /* Return negative value to differentiate return code */
2561 return -ret;
2562 }
2563
2564 ssize_t cmd_list_syscalls(struct lttng_event **events)
2565 {
2566 return syscall_table_list(events);
2567 }
2568
2569 /*
2570 * Command LTTNG_LIST_TRACKER_IDS processed by the client thread.
2571 *
2572 * Called with session lock held.
2573 */
2574 int cmd_list_tracker_ids(enum lttng_tracker_type tracker_type,
2575 struct ltt_session *session,
2576 enum lttng_domain_type domain,
2577 struct lttng_tracker_ids **ids)
2578 {
2579 int ret = LTTNG_OK;
2580
2581 switch (domain) {
2582 case LTTNG_DOMAIN_KERNEL:
2583 {
2584 struct ltt_kernel_session *ksess;
2585
2586 ksess = session->kernel_session;
2587 ret = kernel_list_tracker_ids(tracker_type, ksess, ids);
2588 if (ret != LTTNG_OK) {
2589 ret = -LTTNG_ERR_KERN_LIST_FAIL;
2590 goto error;
2591 }
2592 break;
2593 }
2594 case LTTNG_DOMAIN_UST:
2595 {
2596 struct ltt_ust_session *usess;
2597
2598 usess = session->ust_session;
2599 ret = trace_ust_list_tracker_ids(tracker_type, usess, ids);
2600 if (ret != LTTNG_OK) {
2601 ret = -LTTNG_ERR_UST_LIST_FAIL;
2602 goto error;
2603 }
2604 break;
2605 }
2606 case LTTNG_DOMAIN_LOG4J:
2607 case LTTNG_DOMAIN_JUL:
2608 case LTTNG_DOMAIN_PYTHON:
2609 default:
2610 ret = -LTTNG_ERR_UND;
2611 goto error;
2612 }
2613
2614 error:
2615 /* Return negative value to differentiate return code */
2616 return ret;
2617 }
2618
2619 /*
2620 * Command LTTNG_START_TRACE processed by the client thread.
2621 *
2622 * Called with session mutex held.
2623 */
2624 int cmd_start_trace(struct ltt_session *session)
2625 {
2626 enum lttng_error_code ret;
2627 unsigned long nb_chan = 0;
2628 struct ltt_kernel_session *ksession;
2629 struct ltt_ust_session *usess;
2630 const bool session_rotated_after_last_stop =
2631 session->rotated_after_last_stop;
2632 const bool session_cleared_after_last_stop =
2633 session->cleared_after_last_stop;
2634
2635 assert(session);
2636
2637 /* Ease our life a bit ;) */
2638 ksession = session->kernel_session;
2639 usess = session->ust_session;
2640
2641 /* Is the session already started? */
2642 if (session->active) {
2643 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2644 /* Perform nothing */
2645 goto end;
2646 }
2647
2648 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
2649 !session->current_trace_chunk) {
2650 /*
2651 * A rotation was launched while the session was stopped and
2652 * it has not been completed yet. It is not possible to start
2653 * the session since starting the session here would require a
2654 * rotation from "NULL" to a new trace chunk. That rotation
2655 * would overlap with the ongoing rotation, which is not
2656 * supported.
2657 */
2658 WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
2659 session->name);
2660 ret = LTTNG_ERR_ROTATION_PENDING;
2661 goto error;
2662 }
2663
2664 /*
2665 * Starting a session without channel is useless since after that it's not
2666 * possible to enable channel thus inform the client.
2667 */
2668 if (usess && usess->domain_global.channels) {
2669 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2670 }
2671 if (ksession) {
2672 nb_chan += ksession->channel_count;
2673 }
2674 if (!nb_chan) {
2675 ret = LTTNG_ERR_NO_CHANNEL;
2676 goto error;
2677 }
2678
2679 session->active = 1;
2680 session->rotated_after_last_stop = false;
2681 session->cleared_after_last_stop = false;
2682 if (session->output_traces && !session->current_trace_chunk) {
2683 if (!session->has_been_started) {
2684 struct lttng_trace_chunk *trace_chunk;
2685
2686 DBG("Creating initial trace chunk of session \"%s\"",
2687 session->name);
2688 trace_chunk = session_create_new_trace_chunk(
2689 session, NULL, NULL, NULL);
2690 if (!trace_chunk) {
2691 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2692 goto error;
2693 }
2694 assert(!session->current_trace_chunk);
2695 ret = session_set_trace_chunk(session, trace_chunk,
2696 NULL);
2697 lttng_trace_chunk_put(trace_chunk);
2698 if (ret) {
2699 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2700 goto error;
2701 }
2702 } else {
2703 DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
2704 session->name);
2705 /*
2706 * Rotate existing streams into the new chunk.
2707 * This is a "quiet" rotation has no client has
2708 * explicitly requested this operation.
2709 *
2710 * There is also no need to wait for the rotation
2711 * to complete as it will happen immediately. No data
2712 * was produced as the session was stopped, so the
2713 * rotation should happen on reception of the command.
2714 */
2715 ret = cmd_rotate_session(session, NULL, true,
2716 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
2717 if (ret != LTTNG_OK) {
2718 goto error;
2719 }
2720 }
2721 }
2722
2723 /* Kernel tracing */
2724 if (ksession != NULL) {
2725 DBG("Start kernel tracing session %s", session->name);
2726 ret = start_kernel_session(ksession);
2727 if (ret != LTTNG_OK) {
2728 goto error;
2729 }
2730 }
2731
2732 /* Flag session that trace should start automatically */
2733 if (usess) {
2734 int int_ret = ust_app_start_trace_all(usess);
2735
2736 if (int_ret < 0) {
2737 ret = LTTNG_ERR_UST_START_FAIL;
2738 goto error;
2739 }
2740 }
2741
2742 /*
2743 * Clear the flag that indicates that a rotation was done while the
2744 * session was stopped.
2745 */
2746 session->rotated_after_last_stop = false;
2747
2748 if (session->rotate_timer_period) {
2749 int int_ret = timer_session_rotation_schedule_timer_start(
2750 session, session->rotate_timer_period);
2751
2752 if (int_ret < 0) {
2753 ERR("Failed to enable rotate timer");
2754 ret = LTTNG_ERR_UNK;
2755 goto error;
2756 }
2757 }
2758
2759 ret = LTTNG_OK;
2760
2761 error:
2762 if (ret == LTTNG_OK) {
2763 /* Flag this after a successful start. */
2764 session->has_been_started |= 1;
2765 } else {
2766 session->active = 0;
2767 /* Restore initial state on error. */
2768 session->rotated_after_last_stop =
2769 session_rotated_after_last_stop;
2770 session->cleared_after_last_stop =
2771 session_cleared_after_last_stop;
2772 }
2773 end:
2774 return ret;
2775 }
2776
2777 /*
2778 * Command LTTNG_STOP_TRACE processed by the client thread.
2779 */
2780 int cmd_stop_trace(struct ltt_session *session)
2781 {
2782 int ret;
2783 struct ltt_kernel_session *ksession;
2784 struct ltt_ust_session *usess;
2785
2786 assert(session);
2787
2788 DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
2789 /* Short cut */
2790 ksession = session->kernel_session;
2791 usess = session->ust_session;
2792
2793 /* Session is not active. Skip everythong and inform the client. */
2794 if (!session->active) {
2795 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2796 goto error;
2797 }
2798
2799 ret = stop_kernel_session(ksession);
2800 if (ret != LTTNG_OK) {
2801 goto error;
2802 }
2803
2804 if (usess && usess->active) {
2805 ret = ust_app_stop_trace_all(usess);
2806 if (ret < 0) {
2807 ret = LTTNG_ERR_UST_STOP_FAIL;
2808 goto error;
2809 }
2810 }
2811
2812 DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
2813 session->id);
2814 /* Flag inactive after a successful stop. */
2815 session->active = 0;
2816 ret = LTTNG_OK;
2817
2818 error:
2819 return ret;
2820 }
2821
2822 /*
2823 * Set the base_path of the session only if subdir of a control uris is set.
2824 * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
2825 */
2826 static int set_session_base_path_from_uris(struct ltt_session *session,
2827 size_t nb_uri,
2828 struct lttng_uri *uris)
2829 {
2830 int ret;
2831 size_t i;
2832
2833 for (i = 0; i < nb_uri; i++) {
2834 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2835 uris[i].subdir[0] == '\0') {
2836 /* Not interested in these URIs */
2837 continue;
2838 }
2839
2840 if (session->base_path != NULL) {
2841 free(session->base_path);
2842 session->base_path = NULL;
2843 }
2844
2845 /* Set session base_path */
2846 session->base_path = strdup(uris[i].subdir);
2847 if (!session->base_path) {
2848 PERROR("Failed to copy base path \"%s\" to session \"%s\"",
2849 uris[i].subdir, session->name);
2850 ret = LTTNG_ERR_NOMEM;
2851 goto error;
2852 }
2853 DBG2("Setting base path \"%s\" for session \"%s\"",
2854 session->base_path, session->name);
2855 }
2856 ret = LTTNG_OK;
2857 error:
2858 return ret;
2859 }
2860
2861 /*
2862 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2863 */
2864 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2865 struct lttng_uri *uris)
2866 {
2867 int ret, i;
2868 struct ltt_kernel_session *ksess = session->kernel_session;
2869 struct ltt_ust_session *usess = session->ust_session;
2870
2871 assert(session);
2872 assert(uris);
2873 assert(nb_uri > 0);
2874
2875 /* Can't set consumer URI if the session is active. */
2876 if (session->active) {
2877 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2878 goto error;
2879 }
2880
2881 /*
2882 * Set the session base path if any. This is done inside
2883 * cmd_set_consumer_uri to preserve backward compatibility of the
2884 * previous session creation api vs the session descriptor api.
2885 */
2886 ret = set_session_base_path_from_uris(session, nb_uri, uris);
2887 if (ret != LTTNG_OK) {
2888 goto error;
2889 }
2890
2891 /* Set the "global" consumer URIs */
2892 for (i = 0; i < nb_uri; i++) {
2893 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2894 LTTNG_DOMAIN_NONE);
2895 if (ret != LTTNG_OK) {
2896 goto error;
2897 }
2898 }
2899
2900 /* Set UST session URIs */
2901 if (session->ust_session) {
2902 for (i = 0; i < nb_uri; i++) {
2903 ret = add_uri_to_consumer(session,
2904 session->ust_session->consumer,
2905 &uris[i], LTTNG_DOMAIN_UST);
2906 if (ret != LTTNG_OK) {
2907 goto error;
2908 }
2909 }
2910 }
2911
2912 /* Set kernel session URIs */
2913 if (session->kernel_session) {
2914 for (i = 0; i < nb_uri; i++) {
2915 ret = add_uri_to_consumer(session,
2916 session->kernel_session->consumer,
2917 &uris[i], LTTNG_DOMAIN_KERNEL);
2918 if (ret != LTTNG_OK) {
2919 goto error;
2920 }
2921 }
2922 }
2923
2924 /*
2925 * Make sure to set the session in output mode after we set URI since a
2926 * session can be created without URL (thus flagged in no output mode).
2927 */
2928 session->output_traces = 1;
2929 if (ksess) {
2930 ksess->output_traces = 1;
2931 }
2932
2933 if (usess) {
2934 usess->output_traces = 1;
2935 }
2936
2937 /* All good! */
2938 ret = LTTNG_OK;
2939
2940 error:
2941 return ret;
2942 }
2943
2944 static
2945 enum lttng_error_code set_session_output_from_descriptor(
2946 struct ltt_session *session,
2947 const struct lttng_session_descriptor *descriptor)
2948 {
2949 int ret;
2950 enum lttng_error_code ret_code = LTTNG_OK;
2951 enum lttng_session_descriptor_type session_type =
2952 lttng_session_descriptor_get_type(descriptor);
2953 enum lttng_session_descriptor_output_type output_type =
2954 lttng_session_descriptor_get_output_type(descriptor);
2955 struct lttng_uri uris[2] = {};
2956 size_t uri_count = 0;
2957
2958 switch (output_type) {
2959 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2960 goto end;
2961 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2962 lttng_session_descriptor_get_local_output_uri(descriptor,
2963 &uris[0]);
2964 uri_count = 1;
2965 break;
2966 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2967 lttng_session_descriptor_get_network_output_uris(descriptor,
2968 &uris[0], &uris[1]);
2969 uri_count = 2;
2970 break;
2971 default:
2972 ret_code = LTTNG_ERR_INVALID;
2973 goto end;
2974 }
2975
2976 switch (session_type) {
2977 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2978 {
2979 struct snapshot_output *new_output = NULL;
2980
2981 new_output = snapshot_output_alloc();
2982 if (!new_output) {
2983 ret_code = LTTNG_ERR_NOMEM;
2984 goto end;
2985 }
2986
2987 ret = snapshot_output_init_with_uri(session,
2988 DEFAULT_SNAPSHOT_MAX_SIZE,
2989 NULL, uris, uri_count, session->consumer,
2990 new_output, &session->snapshot);
2991 if (ret < 0) {
2992 ret_code = (ret == -ENOMEM) ?
2993 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2994 snapshot_output_destroy(new_output);
2995 goto end;
2996 }
2997 snapshot_add_output(&session->snapshot, new_output);
2998 break;
2999 }
3000 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
3001 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3002 {
3003 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
3004 break;
3005 }
3006 default:
3007 ret_code = LTTNG_ERR_INVALID;
3008 goto end;
3009 }
3010 end:
3011 return ret_code;
3012 }
3013
3014 static
3015 enum lttng_error_code cmd_create_session_from_descriptor(
3016 struct lttng_session_descriptor *descriptor,
3017 const lttng_sock_cred *creds,
3018 const char *home_path)
3019 {
3020 int ret;
3021 enum lttng_error_code ret_code;
3022 const char *session_name;
3023 struct ltt_session *new_session = NULL;
3024 enum lttng_session_descriptor_status descriptor_status;
3025
3026 session_lock_list();
3027 if (home_path) {
3028 if (*home_path != '/') {
3029 ERR("Home path provided by client is not absolute");
3030 ret_code = LTTNG_ERR_INVALID;
3031 goto end;
3032 }
3033 }
3034
3035 descriptor_status = lttng_session_descriptor_get_session_name(
3036 descriptor, &session_name);
3037 switch (descriptor_status) {
3038 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
3039 break;
3040 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
3041 session_name = NULL;
3042 break;
3043 default:
3044 ret_code = LTTNG_ERR_INVALID;
3045 goto end;
3046 }
3047
3048 ret_code = session_create(session_name, creds->uid, creds->gid,
3049 &new_session);
3050 if (ret_code != LTTNG_OK) {
3051 goto end;
3052 }
3053
3054 if (!session_name) {
3055 ret = lttng_session_descriptor_set_session_name(descriptor,
3056 new_session->name);
3057 if (ret) {
3058 ret_code = LTTNG_ERR_SESSION_FAIL;
3059 goto end;
3060 }
3061 }
3062
3063 if (!lttng_session_descriptor_is_output_destination_initialized(
3064 descriptor)) {
3065 /*
3066 * Only include the session's creation time in the output
3067 * destination if the name of the session itself was
3068 * not auto-generated.
3069 */
3070 ret_code = lttng_session_descriptor_set_default_output(
3071 descriptor,
3072 session_name ? &new_session->creation_time : NULL,
3073 home_path);
3074 if (ret_code != LTTNG_OK) {
3075 goto end;
3076 }
3077 } else {
3078 new_session->has_user_specified_directory =
3079 lttng_session_descriptor_has_output_directory(
3080 descriptor);
3081 }
3082
3083 switch (lttng_session_descriptor_get_type(descriptor)) {
3084 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
3085 new_session->snapshot_mode = 1;
3086 break;
3087 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
3088 new_session->live_timer =
3089 lttng_session_descriptor_live_get_timer_interval(
3090 descriptor);
3091 break;
3092 default:
3093 break;
3094 }
3095
3096 ret_code = set_session_output_from_descriptor(new_session, descriptor);
3097 if (ret_code != LTTNG_OK) {
3098 goto end;
3099 }
3100 new_session->consumer->enabled = 1;
3101 ret_code = LTTNG_OK;
3102 end:
3103 /* Release reference provided by the session_create function. */
3104 session_put(new_session);
3105 if (ret_code != LTTNG_OK && new_session) {
3106 /* Release the global reference on error. */
3107 session_destroy(new_session);
3108 }
3109 session_unlock_list();
3110 return ret_code;
3111 }
3112
3113 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3114 struct lttng_session_descriptor **return_descriptor)
3115 {
3116 int ret;
3117 size_t payload_size;
3118 struct lttng_dynamic_buffer payload;
3119 struct lttng_buffer_view home_dir_view;
3120 struct lttng_buffer_view session_descriptor_view;
3121 struct lttng_session_descriptor *session_descriptor = NULL;
3122 enum lttng_error_code ret_code;
3123
3124 lttng_dynamic_buffer_init(&payload);
3125 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
3126 LTTNG_PATH_MAX) {
3127 ret_code = LTTNG_ERR_INVALID;
3128 goto error;
3129 }
3130 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3131 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3132 ret_code = LTTNG_ERR_INVALID;
3133 goto error;
3134 }
3135
3136 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3137 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3138 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3139 if (ret) {
3140 ret_code = LTTNG_ERR_NOMEM;
3141 goto error;
3142 }
3143
3144 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3145 if (ret <= 0) {
3146 ERR("Reception of session descriptor failed, aborting.");
3147 ret_code = LTTNG_ERR_SESSION_FAIL;
3148 goto error;
3149 }
3150
3151 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3152 &payload,
3153 0,
3154 cmd_ctx->lsm->u.create_session.home_dir_size);
3155 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3156 &payload,
3157 cmd_ctx->lsm->u.create_session.home_dir_size,
3158 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3159
3160 ret = lttng_session_descriptor_create_from_buffer(
3161 &session_descriptor_view, &session_descriptor);
3162 if (ret < 0) {
3163 ERR("Failed to create session descriptor from payload of \"create session\" command");
3164 ret_code = LTTNG_ERR_INVALID;
3165 goto error;
3166 }
3167
3168 /*
3169 * Sets the descriptor's auto-generated properties (name, output) if
3170 * needed.
3171 */
3172 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3173 &cmd_ctx->creds,
3174 home_dir_view.size ? home_dir_view.data : NULL);
3175 if (ret_code != LTTNG_OK) {
3176 goto error;
3177 }
3178
3179 ret_code = LTTNG_OK;
3180 *return_descriptor = session_descriptor;
3181 session_descriptor = NULL;
3182 error:
3183 lttng_dynamic_buffer_reset(&payload);
3184 lttng_session_descriptor_destroy(session_descriptor);
3185 return ret_code;
3186 }
3187
3188 static
3189 void cmd_destroy_session_reply(const struct ltt_session *session,
3190 void *_reply_context)
3191 {
3192 int ret;
3193 ssize_t comm_ret;
3194 const struct cmd_destroy_session_reply_context *reply_context =
3195 _reply_context;
3196 struct lttng_dynamic_buffer payload;
3197 struct lttcomm_session_destroy_command_header cmd_header;
3198 struct lttng_trace_archive_location *location = NULL;
3199 struct lttcomm_lttng_msg llm = {
3200 .cmd_type = LTTNG_DESTROY_SESSION,
3201 .ret_code = reply_context->destruction_status,
3202 .pid = UINT32_MAX,
3203 .cmd_header_size =
3204 sizeof(struct lttcomm_session_destroy_command_header),
3205 .data_size = 0,
3206 };
3207 size_t payload_size_before_location;
3208
3209 lttng_dynamic_buffer_init(&payload);
3210
3211 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3212 if (ret) {
3213 ERR("Failed to append session destruction message");
3214 goto error;
3215 }
3216
3217 cmd_header.rotation_state =
3218 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3219 session->rotation_state :
3220 LTTNG_ROTATION_STATE_NO_ROTATION);
3221 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3222 sizeof(cmd_header));
3223 if (ret) {
3224 ERR("Failed to append session destruction command header");
3225 goto error;
3226 }
3227
3228 if (!reply_context->implicit_rotation_on_destroy) {
3229 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3230 session->name);
3231 goto send_reply;
3232 }
3233 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3234 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3235 session->name);
3236 goto send_reply;
3237 }
3238
3239 location = session_get_trace_archive_location(session);
3240 if (!location) {
3241 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3242 session->name);
3243 goto error;
3244 }
3245
3246 payload_size_before_location = payload.size;
3247 comm_ret = lttng_trace_archive_location_serialize(location,
3248 &payload);
3249 if (comm_ret < 0) {
3250 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3251 session->name);
3252 goto error;
3253 }
3254 /* Update the message to indicate the location's length. */
3255 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3256 payload.size - payload_size_before_location;
3257 send_reply:
3258 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3259 payload.data, payload.size);
3260 if (comm_ret != (ssize_t) payload.size) {
3261 ERR("Failed to send result of the destruction of session \"%s\" to client",
3262 session->name);
3263 }
3264 error:
3265 ret = close(reply_context->reply_sock_fd);
3266 if (ret) {
3267 PERROR("Failed to close client socket in deferred session destroy reply");
3268 }
3269 lttng_dynamic_buffer_reset(&payload);
3270 free(_reply_context);
3271 }
3272
3273 /*
3274 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3275 *
3276 * Called with session lock held.
3277 */
3278 int cmd_destroy_session(struct ltt_session *session,
3279 struct notification_thread_handle *notification_thread_handle,
3280 int *sock_fd)
3281 {
3282 int ret;
3283 enum lttng_error_code destruction_last_error = LTTNG_OK;
3284 struct cmd_destroy_session_reply_context *reply_context = NULL;
3285
3286 if (sock_fd) {
3287 reply_context = zmalloc(sizeof(*reply_context));
3288 if (!reply_context) {
3289 ret = LTTNG_ERR_NOMEM;
3290 goto end;
3291 }
3292 reply_context->reply_sock_fd = *sock_fd;
3293 }
3294
3295 /* Safety net */
3296 assert(session);
3297
3298 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3299 session->id);
3300 if (session->active) {
3301 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3302 session->name);
3303 ret = cmd_stop_trace(session);
3304 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3305 /* Carry on with the destruction of the session. */
3306 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3307 session->name, lttng_strerror(-ret));
3308 destruction_last_error = ret;
3309 }
3310 }
3311
3312 if (session->rotation_schedule_timer_enabled) {
3313 if (timer_session_rotation_schedule_timer_stop(
3314 session)) {
3315 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3316 session->name);
3317 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3318 }
3319 }
3320
3321 if (session->rotate_size) {
3322 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3323 session->rotate_size = 0;
3324 }
3325
3326 if (session->rotated && session->current_trace_chunk && session->output_traces) {
3327 /*
3328 * Perform a last rotation on destruction if rotations have
3329 * occurred during the session's lifetime.
3330 */
3331 ret = cmd_rotate_session(session, NULL, false,
3332 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
3333 if (ret != LTTNG_OK) {
3334 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3335 session->name, lttng_strerror(-ret));
3336 destruction_last_error = -ret;
3337 }
3338 if (reply_context) {
3339 reply_context->implicit_rotation_on_destroy = true;
3340 }
3341 } else if (session->has_been_started && session->current_trace_chunk) {
3342 /*
3343 * The user has not triggered a session rotation. However, to
3344 * ensure all data has been consumed, the session is rotated
3345 * to a 'null' trace chunk before it is destroyed.
3346 *
3347 * This is a "quiet" rotation meaning that no notification is
3348 * emitted and no renaming of the current trace chunk takes
3349 * place.
3350 */
3351 ret = cmd_rotate_session(session, NULL, true,
3352 LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
3353 if (ret != LTTNG_OK) {
3354 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3355 session->name, lttng_strerror(-ret));
3356 destruction_last_error = -ret;
3357 }
3358 }
3359
3360 if (session->shm_path[0]) {
3361 /*
3362 * When a session is created with an explicit shm_path,
3363 * the consumer daemon will create its shared memory files
3364 * at that location and will *not* unlink them. This is normal
3365 * as the intention of that feature is to make it possible
3366 * to retrieve the content of those files should a crash occur.
3367 *
3368 * To ensure the content of those files can be used, the
3369 * sessiond daemon will replicate the content of the metadata
3370 * cache in a metadata file.
3371 *
3372 * On clean-up, it is expected that the consumer daemon will
3373 * unlink the shared memory files and that the session daemon
3374 * will unlink the metadata file. Then, the session's directory
3375 * in the shm path can be removed.
3376 *
3377 * Unfortunately, a flaw in the design of the sessiond's and
3378 * consumerd's tear down of channels makes it impossible to
3379 * determine when the sessiond _and_ the consumerd have both
3380 * destroyed their representation of a channel. For one, the
3381 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3382 * callbacks in both daemons.
3383 *
3384 * However, it is also impossible for the sessiond to know when
3385 * the consumer daemon is done destroying its channel(s) since
3386 * it occurs as a reaction to the closing of the channel's file
3387 * descriptor. There is no resulting communication initiated
3388 * from the consumerd to the sessiond to confirm that the
3389 * operation is completed (and was successful).
3390 *
3391 * Until this is all fixed, the session daemon checks for the
3392 * removal of the session's shm path which makes it possible
3393 * to safely advertise a session as having been destroyed.
3394 *
3395 * Prior to this fix, it was not possible to reliably save
3396 * a session making use of the --shm-path option, destroy it,
3397 * and load it again. This is because the creation of the
3398 * session would fail upon seeing the session's shm path
3399 * already in existence.
3400 *
3401 * Note that none of the error paths in the check for the
3402 * directory's existence return an error. This is normal
3403 * as there isn't much that can be done. The session will
3404 * be destroyed properly, except that we can't offer the
3405 * guarantee that the same session can be re-created.
3406 */
3407 current_completion_handler = &destroy_completion_handler.handler;
3408 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3409 session->shm_path,
3410 sizeof(destroy_completion_handler.shm_path));
3411 assert(!ret);
3412 }
3413
3414 /*
3415 * The session is destroyed. However, note that the command context
3416 * still holds a reference to the session, thus delaying its destruction
3417 * _at least_ up to the point when that reference is released.
3418 */
3419 session_destroy(session);
3420 if (reply_context) {
3421 reply_context->destruction_status = destruction_last_error;
3422 ret = session_add_destroy_notifier(session,
3423 cmd_destroy_session_reply,
3424 (void *) reply_context);
3425 if (ret) {
3426 ret = LTTNG_ERR_FATAL;
3427 goto end;
3428 } else {
3429 *sock_fd = -1;
3430 }
3431 }
3432 ret = LTTNG_OK;
3433 end:
3434 return ret;
3435 }
3436
3437 /*
3438 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3439 */
3440 int cmd_register_consumer(struct ltt_session *session,
3441 enum lttng_domain_type domain, const char *sock_path,
3442 struct consumer_data *cdata)
3443 {
3444 int ret, sock;
3445 struct consumer_socket *socket = NULL;
3446
3447 assert(session);
3448 assert(cdata);
3449 assert(sock_path);
3450
3451 switch (domain) {
3452 case LTTNG_DOMAIN_KERNEL:
3453 {
3454 struct ltt_kernel_session *ksess = session->kernel_session;
3455
3456 assert(ksess);
3457
3458 /* Can't register a consumer if there is already one */
3459 if (ksess->consumer_fds_sent != 0) {
3460 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3461 goto error;
3462 }
3463
3464 sock = lttcomm_connect_unix_sock(sock_path);
3465 if (sock < 0) {
3466 ret = LTTNG_ERR_CONNECT_FAIL;
3467 goto error;
3468 }
3469 cdata->cmd_sock = sock;
3470
3471 socket = consumer_allocate_socket(&cdata->cmd_sock);
3472 if (socket == NULL) {
3473 ret = close(sock);
3474 if (ret < 0) {
3475 PERROR("close register consumer");
3476 }
3477 cdata->cmd_sock = -1;
3478 ret = LTTNG_ERR_FATAL;
3479 goto error;
3480 }
3481
3482 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3483 if (socket->lock == NULL) {
3484 PERROR("zmalloc pthread mutex");
3485 ret = LTTNG_ERR_FATAL;
3486 goto error;
3487 }
3488 pthread_mutex_init(socket->lock, NULL);
3489 socket->registered = 1;
3490
3491 rcu_read_lock();
3492 consumer_add_socket(socket, ksess->consumer);
3493 rcu_read_unlock();
3494
3495 pthread_mutex_lock(&cdata->pid_mutex);
3496 cdata->pid = -1;
3497 pthread_mutex_unlock(&cdata->pid_mutex);
3498
3499 break;
3500 }
3501 default:
3502 /* TODO: Userspace tracing */
3503 ret = LTTNG_ERR_UND;
3504 goto error;
3505 }
3506
3507 return LTTNG_OK;
3508
3509 error:
3510 if (socket) {
3511 consumer_destroy_socket(socket);
3512 }
3513 return ret;
3514 }
3515
3516 /*
3517 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3518 */
3519 ssize_t cmd_list_domains(struct ltt_session *session,
3520 struct lttng_domain **domains)
3521 {
3522 int ret, index = 0;
3523 ssize_t nb_dom = 0;
3524 struct agent *agt;
3525 struct lttng_ht_iter iter;
3526
3527 if (session->kernel_session != NULL) {
3528 DBG3("Listing domains found kernel domain");
3529 nb_dom++;
3530 }
3531
3532 if (session->ust_session != NULL) {
3533 DBG3("Listing domains found UST global domain");
3534 nb_dom++;
3535
3536 rcu_read_lock();
3537 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3538 agt, node.node) {
3539 if (agt->being_used) {
3540 nb_dom++;
3541 }
3542 }
3543 rcu_read_unlock();
3544 }
3545
3546 if (!nb_dom) {
3547 goto end;
3548 }
3549
3550 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3551 if (*domains == NULL) {
3552 ret = LTTNG_ERR_FATAL;
3553 goto error;
3554 }
3555
3556 if (session->kernel_session != NULL) {
3557 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3558
3559 /* Kernel session buffer type is always GLOBAL */
3560 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3561
3562 index++;
3563 }
3564
3565 if (session->ust_session != NULL) {
3566 (*domains)[index].type = LTTNG_DOMAIN_UST;
3567 (*domains)[index].buf_type = session->ust_session->buffer_type;
3568 index++;
3569
3570 rcu_read_lock();
3571 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3572 agt, node.node) {
3573 if (agt->being_used) {
3574 (*domains)[index].type = agt->domain;
3575 (*domains)[index].buf_type = session->ust_session->buffer_type;
3576 index++;
3577 }
3578 }
3579 rcu_read_unlock();
3580 }
3581 end:
3582 return nb_dom;
3583
3584 error:
3585 /* Return negative value to differentiate return code */
3586 return -ret;
3587 }
3588
3589
3590 /*
3591 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3592 */
3593 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3594 struct ltt_session *session, struct lttng_channel **channels)
3595 {
3596 ssize_t nb_chan = 0, payload_size = 0, ret;
3597
3598 switch (domain) {
3599 case LTTNG_DOMAIN_KERNEL:
3600 if (session->kernel_session != NULL) {
3601 nb_chan = session->kernel_session->channel_count;
3602 }
3603 DBG3("Number of kernel channels %zd", nb_chan);
3604 if (nb_chan <= 0) {
3605 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3606 goto end;
3607 }
3608 break;
3609 case LTTNG_DOMAIN_UST:
3610 if (session->ust_session != NULL) {
3611 rcu_read_lock();
3612 nb_chan = lttng_ht_get_count(
3613 session->ust_session->domain_global.channels);
3614 rcu_read_unlock();
3615 }
3616 DBG3("Number of UST global channels %zd", nb_chan);
3617 if (nb_chan < 0) {
3618 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3619 goto end;
3620 }
3621 break;
3622 default:
3623 ret = -LTTNG_ERR_UND;
3624 goto end;
3625 }
3626
3627 if (nb_chan > 0) {
3628 const size_t channel_size = sizeof(struct lttng_channel) +
3629 sizeof(struct lttng_channel_extended);
3630 struct lttng_channel_extended *channel_exts;
3631
3632 payload_size = nb_chan * channel_size;
3633 *channels = zmalloc(payload_size);
3634 if (*channels == NULL) {
3635 ret = -LTTNG_ERR_FATAL;
3636 goto end;
3637 }
3638
3639 channel_exts = ((void *) *channels) +
3640 (nb_chan * sizeof(struct lttng_channel));
3641 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3642 if (ret != LTTNG_OK) {
3643 free(*channels);
3644 *channels = NULL;
3645 goto end;
3646 }
3647 } else {
3648 *channels = NULL;
3649 }
3650
3651 ret = payload_size;
3652 end:
3653 return ret;
3654 }
3655
3656 /*
3657 * Command LTTNG_LIST_EVENTS processed by the client thread.
3658 */
3659 ssize_t cmd_list_events(enum lttng_domain_type domain,
3660 struct ltt_session *session, char *channel_name,
3661 struct lttng_event **events, size_t *total_size)
3662 {
3663 int ret = 0;
3664 ssize_t nb_event = 0;
3665
3666 switch (domain) {
3667 case LTTNG_DOMAIN_KERNEL:
3668 if (session->kernel_session != NULL) {
3669 nb_event = list_lttng_kernel_events(channel_name,
3670 session->kernel_session, events,
3671 total_size);
3672 }
3673 break;
3674 case LTTNG_DOMAIN_UST:
3675 {
3676 if (session->ust_session != NULL) {
3677 nb_event = list_lttng_ust_global_events(channel_name,
3678 &session->ust_session->domain_global, events,
3679 total_size);
3680 }
3681 break;
3682 }
3683 case LTTNG_DOMAIN_LOG4J:
3684 case LTTNG_DOMAIN_JUL:
3685 case LTTNG_DOMAIN_PYTHON:
3686 if (session->ust_session) {
3687 struct lttng_ht_iter iter;
3688 struct agent *agt;
3689
3690 rcu_read_lock();
3691 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3692 &iter.iter, agt, node.node) {
3693 if (agt->domain == domain) {
3694 nb_event = list_lttng_agent_events(
3695 agt, events,
3696 total_size);
3697 break;
3698 }
3699 }
3700 rcu_read_unlock();
3701 }
3702 break;
3703 default:
3704 ret = LTTNG_ERR_UND;
3705 goto error;
3706 }
3707
3708 return nb_event;
3709
3710 error:
3711 /* Return negative value to differentiate return code */
3712 return -ret;
3713 }
3714
3715 /*
3716 * Using the session list, filled a lttng_session array to send back to the
3717 * client for session listing.
3718 *
3719 * The session list lock MUST be acquired before calling this function. Use
3720 * session_lock_list() and session_unlock_list().
3721 */
3722 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3723 size_t session_count, uid_t uid, gid_t gid)
3724 {
3725 int ret;
3726 unsigned int i = 0;
3727 struct ltt_session *session;
3728 struct ltt_session_list *list = session_get_list();
3729 struct lttng_session_extended *extended =
3730 (typeof(extended)) (&sessions[session_count]);
3731
3732 DBG("Getting all available session for UID %d GID %d",
3733 uid, gid);
3734 /*
3735 * Iterate over session list and append data after the control struct in
3736 * the buffer.
3737 */
3738 cds_list_for_each_entry(session, &list->head, list) {
3739 if (!session_get(session)) {
3740 continue;
3741 }
3742 /*
3743 * Only list the sessions the user can control.
3744 */
3745 if (!session_access_ok(session, uid, gid) ||
3746 session->destroyed) {
3747 session_put(session);
3748 continue;
3749 }
3750
3751 struct ltt_kernel_session *ksess = session->kernel_session;
3752 struct ltt_ust_session *usess = session->ust_session;
3753
3754 if (session->consumer->type == CONSUMER_DST_NET ||
3755 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3756 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3757 ret = build_network_session_path(sessions[i].path,
3758 sizeof(sessions[i].path), session);
3759 } else {
3760