1dec61ea17b6ba7f74e122e37a7df99afa2e07c6
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25 #include <stdio.h>
26
27 #include <common/defaults.h>
28 #include <common/common.h>
29 #include <common/sessiond-comm/sessiond-comm.h>
30 #include <common/relayd/relayd.h>
31 #include <common/utils.h>
32 #include <common/compat/string.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/dynamic-buffer.h>
35 #include <common/buffer-view.h>
36 #include <common/trace-chunk.h>
37 #include <lttng/location-internal.h>
38 #include <lttng/trigger/trigger-internal.h>
39 #include <lttng/condition/condition.h>
40 #include <lttng/action/action.h>
41 #include <lttng/channel.h>
42 #include <lttng/channel-internal.h>
43 #include <lttng/rotate-internal.h>
44 #include <lttng/location-internal.h>
45 #include <lttng/session-internal.h>
46 #include <lttng/userspace-probe-internal.h>
47 #include <lttng/session-descriptor-internal.h>
48 #include <common/string-utils/string-utils.h>
49
50 #include "channel.h"
51 #include "consumer.h"
52 #include "event.h"
53 #include "health-sessiond.h"
54 #include "kernel.h"
55 #include "kernel-consumer.h"
56 #include "lttng-sessiond.h"
57 #include "utils.h"
58 #include "lttng-syscall.h"
59 #include "agent.h"
60 #include "buffer-registry.h"
61 #include "notification-thread.h"
62 #include "notification-thread-commands.h"
63 #include "rotate.h"
64 #include "rotation-thread.h"
65 #include "timer.h"
66 #include "agent-thread.h"
67
68 #include "cmd.h"
69
70 /* Sleep for 100ms between each check for the shm path's deletion. */
71 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
72
73 struct cmd_destroy_session_reply_context {
74 int reply_sock_fd;
75 bool implicit_rotation_on_destroy;
76 /*
77 * Indicates whether or not an error occurred while launching the
78 * destruction of a session.
79 */
80 enum lttng_error_code destruction_status;
81 };
82
83 static enum lttng_error_code wait_on_path(void *path);
84
85 /*
86 * Command completion handler that is used by the destroy command
87 * when a session that has a non-default shm_path is being destroyed.
88 *
89 * See comment in cmd_destroy_session() for the rationale.
90 */
91 static struct destroy_completion_handler {
92 struct cmd_completion_handler handler;
93 char shm_path[member_sizeof(struct ltt_session, shm_path)];
94 } destroy_completion_handler = {
95 .handler = {
96 .run = wait_on_path,
97 .data = destroy_completion_handler.shm_path
98 },
99 .shm_path = { 0 },
100 };
101
102 static struct cmd_completion_handler *current_completion_handler;
103
104 /*
105 * Used to keep a unique index for each relayd socket created where this value
106 * is associated with streams on the consumer so it can match the right relayd
107 * to send to. It must be accessed with the relayd_net_seq_idx_lock
108 * held.
109 */
110 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
111 static uint64_t relayd_net_seq_idx;
112
113 static int validate_ust_event_name(const char *);
114 static int cmd_enable_event_internal(struct ltt_session *session,
115 const struct lttng_domain *domain,
116 char *channel_name, struct lttng_event *event,
117 char *filter_expression,
118 struct lttng_filter_bytecode *filter,
119 struct lttng_event_exclusion *exclusion,
120 int wpipe);
121
122 /*
123 * Create a session path used by list_lttng_sessions for the case that the
124 * session consumer is on the network.
125 */
126 static int build_network_session_path(char *dst, size_t size,
127 struct ltt_session *session)
128 {
129 int ret, kdata_port, udata_port;
130 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
131 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
132
133 assert(session);
134 assert(dst);
135
136 memset(tmp_urls, 0, sizeof(tmp_urls));
137 memset(tmp_uurl, 0, sizeof(tmp_uurl));
138
139 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
140
141 if (session->kernel_session && session->kernel_session->consumer) {
142 kuri = &session->kernel_session->consumer->dst.net.control;
143 kdata_port = session->kernel_session->consumer->dst.net.data.port;
144 }
145
146 if (session->ust_session && session->ust_session->consumer) {
147 uuri = &session->ust_session->consumer->dst.net.control;
148 udata_port = session->ust_session->consumer->dst.net.data.port;
149 }
150
151 if (uuri == NULL && kuri == NULL) {
152 uri = &session->consumer->dst.net.control;
153 kdata_port = session->consumer->dst.net.data.port;
154 } else if (kuri && uuri) {
155 ret = uri_compare(kuri, uuri);
156 if (ret) {
157 /* Not Equal */
158 uri = kuri;
159 /* Build uuri URL string */
160 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
161 if (ret < 0) {
162 goto error;
163 }
164 } else {
165 uri = kuri;
166 }
167 } else if (kuri && uuri == NULL) {
168 uri = kuri;
169 } else if (uuri && kuri == NULL) {
170 uri = uuri;
171 }
172
173 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
174 if (ret < 0) {
175 goto error;
176 }
177
178 /*
179 * Do we have a UST url set. If yes, this means we have both kernel and UST
180 * to print.
181 */
182 if (*tmp_uurl != '\0') {
183 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
184 tmp_urls, kdata_port, tmp_uurl, udata_port);
185 } else {
186 int dport;
187 if (kuri || (!kuri && !uuri)) {
188 dport = kdata_port;
189 } else {
190 /* No kernel URI, use the UST port. */
191 dport = udata_port;
192 }
193 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
194 }
195
196 error:
197 return ret;
198 }
199
200 /*
201 * Get run-time attributes if the session has been started (discarded events,
202 * lost packets).
203 */
204 static int get_kernel_runtime_stats(struct ltt_session *session,
205 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
206 uint64_t *lost_packets)
207 {
208 int ret;
209
210 if (!session->has_been_started) {
211 ret = 0;
212 *discarded_events = 0;
213 *lost_packets = 0;
214 goto end;
215 }
216
217 ret = consumer_get_discarded_events(session->id, kchan->key,
218 session->kernel_session->consumer,
219 discarded_events);
220 if (ret < 0) {
221 goto end;
222 }
223
224 ret = consumer_get_lost_packets(session->id, kchan->key,
225 session->kernel_session->consumer,
226 lost_packets);
227 if (ret < 0) {
228 goto end;
229 }
230
231 end:
232 return ret;
233 }
234
235 /*
236 * Get run-time attributes if the session has been started (discarded events,
237 * lost packets).
238 */
239 static int get_ust_runtime_stats(struct ltt_session *session,
240 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
241 uint64_t *lost_packets)
242 {
243 int ret;
244 struct ltt_ust_session *usess;
245
246 if (!discarded_events || !lost_packets) {
247 ret = -1;
248 goto end;
249 }
250
251 usess = session->ust_session;
252 assert(discarded_events);
253 assert(lost_packets);
254
255 if (!usess || !session->has_been_started) {
256 *discarded_events = 0;
257 *lost_packets = 0;
258 ret = 0;
259 goto end;
260 }
261
262 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
263 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
264 &usess->buffer_reg_uid_list,
265 usess->consumer, uchan->id,
266 uchan->attr.overwrite,
267 discarded_events,
268 lost_packets);
269 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
270 ret = ust_app_pid_get_channel_runtime_stats(usess,
271 uchan, usess->consumer,
272 uchan->attr.overwrite,
273 discarded_events,
274 lost_packets);
275 if (ret < 0) {
276 goto end;
277 }
278 *discarded_events += uchan->per_pid_closed_app_discarded;
279 *lost_packets += uchan->per_pid_closed_app_lost;
280 } else {
281 ERR("Unsupported buffer type");
282 assert(0);
283 ret = -1;
284 goto end;
285 }
286
287 end:
288 return ret;
289 }
290
291 /*
292 * Fill lttng_channel array of all channels.
293 */
294 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
295 struct ltt_session *session, struct lttng_channel *channels,
296 struct lttng_channel_extended *chan_exts)
297 {
298 int i = 0, ret = 0;
299 struct ltt_kernel_channel *kchan;
300
301 DBG("Listing channels for session %s", session->name);
302
303 switch (domain) {
304 case LTTNG_DOMAIN_KERNEL:
305 /* Kernel channels */
306 if (session->kernel_session != NULL) {
307 cds_list_for_each_entry(kchan,
308 &session->kernel_session->channel_list.head, list) {
309 uint64_t discarded_events, lost_packets;
310 struct lttng_channel_extended *extended;
311
312 extended = (struct lttng_channel_extended *)
313 kchan->channel->attr.extended.ptr;
314
315 ret = get_kernel_runtime_stats(session, kchan,
316 &discarded_events, &lost_packets);
317 if (ret < 0) {
318 goto end;
319 }
320 /* Copy lttng_channel struct to array */
321 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
322 channels[i].enabled = kchan->enabled;
323 chan_exts[i].discarded_events =
324 discarded_events;
325 chan_exts[i].lost_packets = lost_packets;
326 chan_exts[i].monitor_timer_interval =
327 extended->monitor_timer_interval;
328 chan_exts[i].blocking_timeout = 0;
329 i++;
330 }
331 }
332 break;
333 case LTTNG_DOMAIN_UST:
334 {
335 struct lttng_ht_iter iter;
336 struct ltt_ust_channel *uchan;
337
338 rcu_read_lock();
339 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
340 &iter.iter, uchan, node.node) {
341 uint64_t discarded_events = 0, lost_packets = 0;
342
343 if (lttng_strncpy(channels[i].name, uchan->name,
344 LTTNG_SYMBOL_NAME_LEN)) {
345 break;
346 }
347 channels[i].attr.overwrite = uchan->attr.overwrite;
348 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
349 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
350 channels[i].attr.switch_timer_interval =
351 uchan->attr.switch_timer_interval;
352 channels[i].attr.read_timer_interval =
353 uchan->attr.read_timer_interval;
354 channels[i].enabled = uchan->enabled;
355 channels[i].attr.tracefile_size = uchan->tracefile_size;
356 channels[i].attr.tracefile_count = uchan->tracefile_count;
357
358 /*
359 * Map enum lttng_ust_output to enum lttng_event_output.
360 */
361 switch (uchan->attr.output) {
362 case LTTNG_UST_MMAP:
363 channels[i].attr.output = LTTNG_EVENT_MMAP;
364 break;
365 default:
366 /*
367 * LTTNG_UST_MMAP is the only supported UST
368 * output mode.
369 */
370 assert(0);
371 break;
372 }
373
374 chan_exts[i].monitor_timer_interval =
375 uchan->monitor_timer_interval;
376 chan_exts[i].blocking_timeout =
377 uchan->attr.u.s.blocking_timeout;
378
379 ret = get_ust_runtime_stats(session, uchan,
380 &discarded_events, &lost_packets);
381 if (ret < 0) {
382 break;
383 }
384 chan_exts[i].discarded_events = discarded_events;
385 chan_exts[i].lost_packets = lost_packets;
386 i++;
387 }
388 rcu_read_unlock();
389 break;
390 }
391 default:
392 break;
393 }
394
395 end:
396 if (ret < 0) {
397 return -LTTNG_ERR_FATAL;
398 } else {
399 return LTTNG_OK;
400 }
401 }
402
403 static int increment_extended_len(const char *filter_expression,
404 struct lttng_event_exclusion *exclusion,
405 const struct lttng_userspace_probe_location *probe_location,
406 size_t *extended_len)
407 {
408 int ret = 0;
409
410 *extended_len += sizeof(struct lttcomm_event_extended_header);
411
412 if (filter_expression) {
413 *extended_len += strlen(filter_expression) + 1;
414 }
415
416 if (exclusion) {
417 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
418 }
419
420 if (probe_location) {
421 ret = lttng_userspace_probe_location_serialize(probe_location,
422 NULL, NULL);
423 if (ret < 0) {
424 goto end;
425 }
426 *extended_len += ret;
427 }
428 ret = 0;
429 end:
430 return ret;
431 }
432
433 static int append_extended_info(const char *filter_expression,
434 struct lttng_event_exclusion *exclusion,
435 struct lttng_userspace_probe_location *probe_location,
436 void **extended_at)
437 {
438 int ret = 0;
439 size_t filter_len = 0;
440 size_t nb_exclusions = 0;
441 size_t userspace_probe_location_len = 0;
442 struct lttng_dynamic_buffer location_buffer;
443 struct lttcomm_event_extended_header extended_header;
444
445 if (filter_expression) {
446 filter_len = strlen(filter_expression) + 1;
447 }
448
449 if (exclusion) {
450 nb_exclusions = exclusion->count;
451 }
452
453 if (probe_location) {
454 lttng_dynamic_buffer_init(&location_buffer);
455 ret = lttng_userspace_probe_location_serialize(probe_location,
456 &location_buffer, NULL);
457 if (ret < 0) {
458 ret = -1;
459 goto end;
460 }
461 userspace_probe_location_len = location_buffer.size;
462 }
463
464 /* Set header fields */
465 extended_header.filter_len = filter_len;
466 extended_header.nb_exclusions = nb_exclusions;
467 extended_header.userspace_probe_location_len = userspace_probe_location_len;
468
469 /* Copy header */
470 memcpy(*extended_at, &extended_header, sizeof(extended_header));
471 *extended_at += sizeof(extended_header);
472
473 /* Copy filter string */
474 if (filter_expression) {
475 memcpy(*extended_at, filter_expression, filter_len);
476 *extended_at += filter_len;
477 }
478
479 /* Copy exclusion names */
480 if (exclusion) {
481 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
482
483 memcpy(*extended_at, &exclusion->names, len);
484 *extended_at += len;
485 }
486
487 if (probe_location) {
488 memcpy(*extended_at, location_buffer.data, location_buffer.size);
489 *extended_at += location_buffer.size;
490 lttng_dynamic_buffer_reset(&location_buffer);
491 }
492 ret = 0;
493 end:
494 return ret;
495 }
496
497 /*
498 * Create a list of agent domain events.
499 *
500 * Return number of events in list on success or else a negative value.
501 */
502 static int list_lttng_agent_events(struct agent *agt,
503 struct lttng_event **events, size_t *total_size)
504 {
505 int i = 0, ret = 0;
506 unsigned int nb_event = 0;
507 struct agent_event *event;
508 struct lttng_event *tmp_events = NULL;
509 struct lttng_ht_iter iter;
510 size_t extended_len = 0;
511 void *extended_at;
512
513 assert(agt);
514 assert(events);
515
516 DBG3("Listing agent events");
517
518 rcu_read_lock();
519 nb_event = lttng_ht_get_count(agt->events);
520 rcu_read_unlock();
521 if (nb_event == 0) {
522 ret = nb_event;
523 *total_size = 0;
524 goto error;
525 }
526
527 /* Compute required extended infos size */
528 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
529
530 /*
531 * This is only valid because the commands which add events are
532 * processed in the same thread as the listing.
533 */
534 rcu_read_lock();
535 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
536 ret = increment_extended_len(event->filter_expression, NULL, NULL,
537 &extended_len);
538 if (ret) {
539 DBG("Error computing the length of extended info message");
540 ret = -LTTNG_ERR_FATAL;
541 goto error;
542 }
543 }
544 rcu_read_unlock();
545
546 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
547 tmp_events = zmalloc(*total_size);
548 if (!tmp_events) {
549 PERROR("zmalloc agent events session");
550 ret = -LTTNG_ERR_FATAL;
551 goto error;
552 }
553
554 extended_at = ((uint8_t *) tmp_events) +
555 nb_event * sizeof(struct lttng_event);
556
557 rcu_read_lock();
558 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
559 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
560 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
561 tmp_events[i].enabled = event->enabled;
562 tmp_events[i].loglevel = event->loglevel_value;
563 tmp_events[i].loglevel_type = event->loglevel_type;
564 i++;
565
566 /* Append extended info */
567 ret = append_extended_info(event->filter_expression, NULL, NULL,
568 &extended_at);
569 if (ret) {
570 DBG("Error appending extended info message");
571 ret = -LTTNG_ERR_FATAL;
572 goto error;
573 }
574 }
575
576 *events = tmp_events;
577 ret = nb_event;
578 assert(nb_event == i);
579
580 end:
581 rcu_read_unlock();
582 return ret;
583 error:
584 free(tmp_events);
585 goto end;
586 }
587
588 /*
589 * Create a list of ust global domain events.
590 */
591 static int list_lttng_ust_global_events(char *channel_name,
592 struct ltt_ust_domain_global *ust_global,
593 struct lttng_event **events, size_t *total_size)
594 {
595 int i = 0, ret = 0;
596 unsigned int nb_event = 0;
597 struct lttng_ht_iter iter;
598 struct lttng_ht_node_str *node;
599 struct ltt_ust_channel *uchan;
600 struct ltt_ust_event *uevent;
601 struct lttng_event *tmp;
602 size_t extended_len = 0;
603 void *extended_at;
604
605 DBG("Listing UST global events for channel %s", channel_name);
606
607 rcu_read_lock();
608
609 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
610 node = lttng_ht_iter_get_node_str(&iter);
611 if (node == NULL) {
612 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
613 goto end;
614 }
615
616 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
617
618 nb_event = lttng_ht_get_count(uchan->events);
619 if (nb_event == 0) {
620 ret = nb_event;
621 *total_size = 0;
622 goto end;
623 }
624
625 DBG3("Listing UST global %d events", nb_event);
626
627 /* Compute required extended infos size */
628 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
629 if (uevent->internal) {
630 nb_event--;
631 continue;
632 }
633
634 ret = increment_extended_len(uevent->filter_expression,
635 uevent->exclusion, NULL, &extended_len);
636 if (ret) {
637 DBG("Error computing the length of extended info message");
638 ret = -LTTNG_ERR_FATAL;
639 goto end;
640 }
641 }
642 if (nb_event == 0) {
643 /* All events are internal, skip. */
644 ret = 0;
645 *total_size = 0;
646 goto end;
647 }
648
649 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
650 tmp = zmalloc(*total_size);
651 if (tmp == NULL) {
652 ret = -LTTNG_ERR_FATAL;
653 goto end;
654 }
655
656 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
657
658 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
659 if (uevent->internal) {
660 /* This event should remain hidden from clients */
661 continue;
662 }
663 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
664 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
665 tmp[i].enabled = uevent->enabled;
666
667 switch (uevent->attr.instrumentation) {
668 case LTTNG_UST_TRACEPOINT:
669 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
670 break;
671 case LTTNG_UST_PROBE:
672 tmp[i].type = LTTNG_EVENT_PROBE;
673 break;
674 case LTTNG_UST_FUNCTION:
675 tmp[i].type = LTTNG_EVENT_FUNCTION;
676 break;
677 }
678
679 tmp[i].loglevel = uevent->attr.loglevel;
680 switch (uevent->attr.loglevel_type) {
681 case LTTNG_UST_LOGLEVEL_ALL:
682 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
683 break;
684 case LTTNG_UST_LOGLEVEL_RANGE:
685 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
686 break;
687 case LTTNG_UST_LOGLEVEL_SINGLE:
688 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
689 break;
690 }
691 if (uevent->filter) {
692 tmp[i].filter = 1;
693 }
694 if (uevent->exclusion) {
695 tmp[i].exclusion = 1;
696 }
697 i++;
698
699 /* Append extended info */
700 ret = append_extended_info(uevent->filter_expression,
701 uevent->exclusion, NULL, &extended_at);
702 if (ret) {
703 DBG("Error appending extended info message");
704 ret = -LTTNG_ERR_FATAL;
705 goto end;
706 }
707 }
708
709 ret = nb_event;
710 *events = tmp;
711 end:
712 rcu_read_unlock();
713 return ret;
714 }
715
716 /*
717 * Fill lttng_event array of all kernel events in the channel.
718 */
719 static int list_lttng_kernel_events(char *channel_name,
720 struct ltt_kernel_session *kernel_session,
721 struct lttng_event **events, size_t *total_size)
722 {
723 int i = 0, ret;
724 unsigned int nb_event;
725 struct ltt_kernel_event *event;
726 struct ltt_kernel_channel *kchan;
727 size_t extended_len = 0;
728 void *extended_at;
729
730 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
731 if (kchan == NULL) {
732 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
733 goto error;
734 }
735
736 nb_event = kchan->event_count;
737
738 DBG("Listing events for channel %s", kchan->channel->name);
739
740 if (nb_event == 0) {
741 *total_size = 0;
742 *events = NULL;
743 goto end;
744 }
745
746 /* Compute required extended infos size */
747 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
748 ret = increment_extended_len(event->filter_expression, NULL,
749 event->userspace_probe_location,
750 &extended_len);
751 if (ret) {
752 DBG("Error computing the length of extended info message");
753 ret = -LTTNG_ERR_FATAL;
754 goto error;
755 }
756 }
757
758 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
759 *events = zmalloc(*total_size);
760 if (*events == NULL) {
761 ret = -LTTNG_ERR_FATAL;
762 goto error;
763 }
764
765 extended_at = ((void *) *events) +
766 nb_event * sizeof(struct lttng_event);
767
768 /* Kernel channels */
769 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
770 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
771 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
772 (*events)[i].enabled = event->enabled;
773 (*events)[i].filter =
774 (unsigned char) !!event->filter_expression;
775
776 switch (event->event->instrumentation) {
777 case LTTNG_KERNEL_TRACEPOINT:
778 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
779 break;
780 case LTTNG_KERNEL_KRETPROBE:
781 (*events)[i].type = LTTNG_EVENT_FUNCTION;
782 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
783 sizeof(struct lttng_kernel_kprobe));
784 break;
785 case LTTNG_KERNEL_KPROBE:
786 (*events)[i].type = LTTNG_EVENT_PROBE;
787 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
788 sizeof(struct lttng_kernel_kprobe));
789 break;
790 case LTTNG_KERNEL_UPROBE:
791 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
792 break;
793 case LTTNG_KERNEL_FUNCTION:
794 (*events)[i].type = LTTNG_EVENT_FUNCTION;
795 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
796 sizeof(struct lttng_kernel_function));
797 break;
798 case LTTNG_KERNEL_NOOP:
799 (*events)[i].type = LTTNG_EVENT_NOOP;
800 break;
801 case LTTNG_KERNEL_SYSCALL:
802 (*events)[i].type = LTTNG_EVENT_SYSCALL;
803 break;
804 case LTTNG_KERNEL_ALL:
805 /* fall-through. */
806 default:
807 assert(0);
808 break;
809 }
810 i++;
811
812 /* Append extended info */
813 ret = append_extended_info(event->filter_expression, NULL,
814 event->userspace_probe_location, &extended_at);
815 if (ret) {
816 DBG("Error appending extended info message");
817 ret = -LTTNG_ERR_FATAL;
818 goto error;
819 }
820 }
821
822 end:
823 return nb_event;
824
825 error:
826 /* Negate the error code to differentiate the size from an error */
827 return -ret;
828 }
829
830 /*
831 * Add URI so the consumer output object. Set the correct path depending on the
832 * domain adding the default trace directory.
833 */
834 static enum lttng_error_code add_uri_to_consumer(
835 const struct ltt_session *session,
836 struct consumer_output *consumer,
837 struct lttng_uri *uri, enum lttng_domain_type domain)
838 {
839 int ret;
840 enum lttng_error_code ret_code = LTTNG_OK;
841
842 assert(uri);
843
844 if (consumer == NULL) {
845 DBG("No consumer detected. Don't add URI. Stopping.");
846 ret_code = LTTNG_ERR_NO_CONSUMER;
847 goto error;
848 }
849
850 switch (domain) {
851 case LTTNG_DOMAIN_KERNEL:
852 ret = lttng_strncpy(consumer->domain_subdir,
853 DEFAULT_KERNEL_TRACE_DIR,
854 sizeof(consumer->domain_subdir));
855 break;
856 case LTTNG_DOMAIN_UST:
857 ret = lttng_strncpy(consumer->domain_subdir,
858 DEFAULT_UST_TRACE_DIR,
859 sizeof(consumer->domain_subdir));
860 break;
861 default:
862 /*
863 * This case is possible is we try to add the URI to the global
864 * tracing session consumer object which in this case there is
865 * no subdir.
866 */
867 memset(consumer->domain_subdir, 0,
868 sizeof(consumer->domain_subdir));
869 ret = 0;
870 }
871 if (ret) {
872 ERR("Failed to initialize consumer output domain subdirectory");
873 ret_code = LTTNG_ERR_FATAL;
874 goto error;
875 }
876
877 switch (uri->dtype) {
878 case LTTNG_DST_IPV4:
879 case LTTNG_DST_IPV6:
880 DBG2("Setting network URI to consumer");
881
882 if (consumer->type == CONSUMER_DST_NET) {
883 if ((uri->stype == LTTNG_STREAM_CONTROL &&
884 consumer->dst.net.control_isset) ||
885 (uri->stype == LTTNG_STREAM_DATA &&
886 consumer->dst.net.data_isset)) {
887 ret_code = LTTNG_ERR_URL_EXIST;
888 goto error;
889 }
890 } else {
891 memset(&consumer->dst, 0, sizeof(consumer->dst));
892 }
893
894 /* Set URI into consumer output object */
895 ret = consumer_set_network_uri(session, consumer, uri);
896 if (ret < 0) {
897 ret_code = -ret;
898 goto error;
899 } else if (ret == 1) {
900 /*
901 * URI was the same in the consumer so we do not append the subdir
902 * again so to not duplicate output dir.
903 */
904 ret_code = LTTNG_OK;
905 goto error;
906 }
907 break;
908 case LTTNG_DST_PATH:
909 if (*uri->dst.path != '/' || strstr(uri->dst.path, "../")) {
910 ret_code = LTTNG_ERR_INVALID;
911 goto error;
912 }
913 DBG2("Setting trace directory path from URI to %s",
914 uri->dst.path);
915 memset(&consumer->dst, 0, sizeof(consumer->dst));
916
917 ret = lttng_strncpy(consumer->dst.session_root_path,
918 uri->dst.path,
919 sizeof(consumer->dst.session_root_path));
920 if (ret) {
921 ret_code = LTTNG_ERR_FATAL;
922 goto error;
923 }
924 consumer->type = CONSUMER_DST_LOCAL;
925 break;
926 }
927
928 ret_code = LTTNG_OK;
929 error:
930 return ret_code;
931 }
932
933 /*
934 * Init tracing by creating trace directory and sending fds kernel consumer.
935 */
936 static int init_kernel_tracing(struct ltt_kernel_session *session)
937 {
938 int ret = 0;
939 struct lttng_ht_iter iter;
940 struct consumer_socket *socket;
941
942 assert(session);
943
944 rcu_read_lock();
945
946 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
947 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
948 socket, node.node) {
949 pthread_mutex_lock(socket->lock);
950 ret = kernel_consumer_send_session(socket, session);
951 pthread_mutex_unlock(socket->lock);
952 if (ret < 0) {
953 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
954 goto error;
955 }
956 }
957 }
958
959 error:
960 rcu_read_unlock();
961 return ret;
962 }
963
964 /*
965 * Create a socket to the relayd using the URI.
966 *
967 * On success, the relayd_sock pointer is set to the created socket.
968 * Else, it remains untouched and an LTTng error code is returned.
969 */
970 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
971 struct lttcomm_relayd_sock **relayd_sock,
972 struct consumer_output *consumer)
973 {
974 int ret;
975 enum lttng_error_code status = LTTNG_OK;
976 struct lttcomm_relayd_sock *rsock;
977
978 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
979 RELAYD_VERSION_COMM_MINOR);
980 if (!rsock) {
981 status = LTTNG_ERR_FATAL;
982 goto error;
983 }
984
985 /*
986 * Connect to relayd so we can proceed with a session creation. This call
987 * can possibly block for an arbitrary amount of time to set the health
988 * state to be in poll execution.
989 */
990 health_poll_entry();
991 ret = relayd_connect(rsock);
992 health_poll_exit();
993 if (ret < 0) {
994 ERR("Unable to reach lttng-relayd");
995 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
996 goto free_sock;
997 }
998
999 /* Create socket for control stream. */
1000 if (uri->stype == LTTNG_STREAM_CONTROL) {
1001 DBG3("Creating relayd stream socket from URI");
1002
1003 /* Check relayd version */
1004 ret = relayd_version_check(rsock);
1005 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
1006 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
1007 goto close_sock;
1008 } else if (ret < 0) {
1009 ERR("Unable to reach lttng-relayd");
1010 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1011 goto close_sock;
1012 }
1013 consumer->relay_major_version = rsock->major;
1014 consumer->relay_minor_version = rsock->minor;
1015 } else if (uri->stype == LTTNG_STREAM_DATA) {
1016 DBG3("Creating relayd data socket from URI");
1017 } else {
1018 /* Command is not valid */
1019 ERR("Relayd invalid stream type: %d", uri->stype);
1020 status = LTTNG_ERR_INVALID;
1021 goto close_sock;
1022 }
1023
1024 *relayd_sock = rsock;
1025
1026 return status;
1027
1028 close_sock:
1029 /* The returned value is not useful since we are on an error path. */
1030 (void) relayd_close(rsock);
1031 free_sock:
1032 free(rsock);
1033 error:
1034 return status;
1035 }
1036
1037 /*
1038 * Connect to the relayd using URI and send the socket to the right consumer.
1039 *
1040 * The consumer socket lock must be held by the caller.
1041 *
1042 * Returns LTTNG_OK on success or an LTTng error code on failure.
1043 */
1044 static enum lttng_error_code send_consumer_relayd_socket(
1045 unsigned int session_id,
1046 struct lttng_uri *relayd_uri,
1047 struct consumer_output *consumer,
1048 struct consumer_socket *consumer_sock,
1049 const char *session_name, const char *hostname,
1050 const char *base_path, int session_live_timer,
1051 const uint64_t *current_chunk_id,
1052 time_t session_creation_time,
1053 bool session_name_contains_creation_time)
1054 {
1055 int ret;
1056 struct lttcomm_relayd_sock *rsock = NULL;
1057 enum lttng_error_code status;
1058
1059 /* Connect to relayd and make version check if uri is the control. */
1060 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1061 if (status != LTTNG_OK) {
1062 goto relayd_comm_error;
1063 }
1064 assert(rsock);
1065
1066 /* Set the network sequence index if not set. */
1067 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1068 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1069 /*
1070 * Increment net_seq_idx because we are about to transfer the
1071 * new relayd socket to the consumer.
1072 * Assign unique key so the consumer can match streams.
1073 */
1074 consumer->net_seq_index = ++relayd_net_seq_idx;
1075 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1076 }
1077
1078 /* Send relayd socket to consumer. */
1079 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1080 relayd_uri->stype, session_id,
1081 session_name, hostname, base_path,
1082 session_live_timer, current_chunk_id,
1083 session_creation_time, session_name_contains_creation_time);
1084 if (ret < 0) {
1085 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1086 goto close_sock;
1087 }
1088
1089 /* Flag that the corresponding socket was sent. */
1090 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1091 consumer_sock->control_sock_sent = 1;
1092 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1093 consumer_sock->data_sock_sent = 1;
1094 }
1095
1096 /*
1097 * Close socket which was dup on the consumer side. The session daemon does
1098 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1099 */
1100
1101 close_sock:
1102 if (status != LTTNG_OK) {
1103 /*
1104 * The consumer output for this session should not be used anymore
1105 * since the relayd connection failed thus making any tracing or/and
1106 * streaming not usable.
1107 */
1108 consumer->enabled = 0;
1109 }
1110 (void) relayd_close(rsock);
1111 free(rsock);
1112
1113 relayd_comm_error:
1114 return status;
1115 }
1116
1117 /*
1118 * Send both relayd sockets to a specific consumer and domain. This is a
1119 * helper function to facilitate sending the information to the consumer for a
1120 * session.
1121 *
1122 * The consumer socket lock must be held by the caller.
1123 *
1124 * Returns LTTNG_OK, or an LTTng error code on failure.
1125 */
1126 static enum lttng_error_code send_consumer_relayd_sockets(
1127 enum lttng_domain_type domain,
1128 unsigned int session_id, struct consumer_output *consumer,
1129 struct consumer_socket *sock, const char *session_name,
1130 const char *hostname, const char *base_path, int session_live_timer,
1131 const uint64_t *current_chunk_id, time_t session_creation_time,
1132 bool session_name_contains_creation_time)
1133 {
1134 enum lttng_error_code status = LTTNG_OK;
1135
1136 assert(consumer);
1137 assert(sock);
1138
1139 /* Sending control relayd socket. */
1140 if (!sock->control_sock_sent) {
1141 status = send_consumer_relayd_socket(session_id,
1142 &consumer->dst.net.control, consumer, sock,
1143 session_name, hostname, base_path, session_live_timer,
1144 current_chunk_id, session_creation_time,
1145 session_name_contains_creation_time);
1146 if (status != LTTNG_OK) {
1147 goto error;
1148 }
1149 }
1150
1151 /* Sending data relayd socket. */
1152 if (!sock->data_sock_sent) {
1153 status = send_consumer_relayd_socket(session_id,
1154 &consumer->dst.net.data, consumer, sock,
1155 session_name, hostname, base_path, session_live_timer,
1156 current_chunk_id, session_creation_time,
1157 session_name_contains_creation_time);
1158 if (status != LTTNG_OK) {
1159 goto error;
1160 }
1161 }
1162
1163 error:
1164 return status;
1165 }
1166
1167 /*
1168 * Setup relayd connections for a tracing session. First creates the socket to
1169 * the relayd and send them to the right domain consumer. Consumer type MUST be
1170 * network.
1171 */
1172 int cmd_setup_relayd(struct ltt_session *session)
1173 {
1174 int ret = LTTNG_OK;
1175 struct ltt_ust_session *usess;
1176 struct ltt_kernel_session *ksess;
1177 struct consumer_socket *socket;
1178 struct lttng_ht_iter iter;
1179 LTTNG_OPTIONAL(uint64_t) current_chunk_id = {};
1180
1181 assert(session);
1182
1183 usess = session->ust_session;
1184 ksess = session->kernel_session;
1185
1186 DBG("Setting relayd for session %s", session->name);
1187
1188 if (session->current_trace_chunk) {
1189 enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
1190 session->current_trace_chunk, &current_chunk_id.value);
1191
1192 if (status == LTTNG_TRACE_CHUNK_STATUS_OK) {
1193 current_chunk_id.is_set = true;
1194 } else {
1195 ERR("Failed to get current trace chunk id");
1196 ret = LTTNG_ERR_UNK;
1197 goto error;
1198 }
1199 }
1200
1201 rcu_read_lock();
1202
1203 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1204 && usess->consumer->enabled) {
1205 /* For each consumer socket, send relayd sockets */
1206 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1207 socket, node.node) {
1208 pthread_mutex_lock(socket->lock);
1209 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1210 usess->consumer, socket,
1211 session->name, session->hostname,
1212 session->base_path,
1213 session->live_timer,
1214 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1215 session->creation_time,
1216 session->name_contains_creation_time);
1217 pthread_mutex_unlock(socket->lock);
1218 if (ret != LTTNG_OK) {
1219 goto error;
1220 }
1221 /* Session is now ready for network streaming. */
1222 session->net_handle = 1;
1223 }
1224 session->consumer->relay_major_version =
1225 usess->consumer->relay_major_version;
1226 session->consumer->relay_minor_version =
1227 usess->consumer->relay_minor_version;
1228 }
1229
1230 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1231 && ksess->consumer->enabled) {
1232 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1233 socket, node.node) {
1234 pthread_mutex_lock(socket->lock);
1235 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1236 ksess->consumer, socket,
1237 session->name, session->hostname,
1238 session->base_path,
1239 session->live_timer,
1240 current_chunk_id.is_set ? &current_chunk_id.value : NULL,
1241 session->creation_time,
1242 session->name_contains_creation_time);
1243 pthread_mutex_unlock(socket->lock);
1244 if (ret != LTTNG_OK) {
1245 goto error;
1246 }
1247 /* Session is now ready for network streaming. */
1248 session->net_handle = 1;
1249 }
1250 session->consumer->relay_major_version =
1251 ksess->consumer->relay_major_version;
1252 session->consumer->relay_minor_version =
1253 ksess->consumer->relay_minor_version;
1254 }
1255
1256 error:
1257 rcu_read_unlock();
1258 return ret;
1259 }
1260
1261 /*
1262 * Start a kernel session by opening all necessary streams.
1263 */
1264 static int start_kernel_session(struct ltt_kernel_session *ksess)
1265 {
1266 int ret;
1267 struct ltt_kernel_channel *kchan;
1268
1269 /* Open kernel metadata */
1270 if (ksess->metadata == NULL && ksess->output_traces) {
1271 ret = kernel_open_metadata(ksess);
1272 if (ret < 0) {
1273 ret = LTTNG_ERR_KERN_META_FAIL;
1274 goto error;
1275 }
1276 }
1277
1278 /* Open kernel metadata stream */
1279 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1280 ret = kernel_open_metadata_stream(ksess);
1281 if (ret < 0) {
1282 ERR("Kernel create metadata stream failed");
1283 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1284 goto error;
1285 }
1286 }
1287
1288 /* For each channel */
1289 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1290 if (kchan->stream_count == 0) {
1291 ret = kernel_open_channel_stream(kchan);
1292 if (ret < 0) {
1293 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1294 goto error;
1295 }
1296 /* Update the stream global counter */
1297 ksess->stream_count_global += ret;
1298 }
1299 }
1300
1301 /* Setup kernel consumer socket and send fds to it */
1302 ret = init_kernel_tracing(ksess);
1303 if (ret != 0) {
1304 ret = LTTNG_ERR_KERN_START_FAIL;
1305 goto error;
1306 }
1307
1308 /* This start the kernel tracing */
1309 ret = kernel_start_session(ksess);
1310 if (ret < 0) {
1311 ret = LTTNG_ERR_KERN_START_FAIL;
1312 goto error;
1313 }
1314
1315 /* Quiescent wait after starting trace */
1316 kernel_wait_quiescent();
1317
1318 ksess->active = 1;
1319
1320 ret = LTTNG_OK;
1321
1322 error:
1323 return ret;
1324 }
1325
1326 /*
1327 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1328 */
1329 int cmd_disable_channel(struct ltt_session *session,
1330 enum lttng_domain_type domain, char *channel_name)
1331 {
1332 int ret;
1333 struct ltt_ust_session *usess;
1334
1335 usess = session->ust_session;
1336
1337 rcu_read_lock();
1338
1339 switch (domain) {
1340 case LTTNG_DOMAIN_KERNEL:
1341 {
1342 ret = channel_kernel_disable(session->kernel_session,
1343 channel_name);
1344 if (ret != LTTNG_OK) {
1345 goto error;
1346 }
1347
1348 kernel_wait_quiescent();
1349 break;
1350 }
1351 case LTTNG_DOMAIN_UST:
1352 {
1353 struct ltt_ust_channel *uchan;
1354 struct lttng_ht *chan_ht;
1355
1356 chan_ht = usess->domain_global.channels;
1357
1358 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1359 if (uchan == NULL) {
1360 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1361 goto error;
1362 }
1363
1364 ret = channel_ust_disable(usess, uchan);
1365 if (ret != LTTNG_OK) {
1366 goto error;
1367 }
1368 break;
1369 }
1370 default:
1371 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1372 goto error;
1373 }
1374
1375 ret = LTTNG_OK;
1376
1377 error:
1378 rcu_read_unlock();
1379 return ret;
1380 }
1381
1382 /*
1383 * Command LTTNG_TRACK_PID processed by the client thread.
1384 *
1385 * Called with session lock held.
1386 */
1387 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1388 int pid)
1389 {
1390 int ret;
1391
1392 rcu_read_lock();
1393
1394 switch (domain) {
1395 case LTTNG_DOMAIN_KERNEL:
1396 {
1397 struct ltt_kernel_session *ksess;
1398
1399 ksess = session->kernel_session;
1400
1401 ret = kernel_track_pid(ksess, pid);
1402 if (ret != LTTNG_OK) {
1403 goto error;
1404 }
1405
1406 kernel_wait_quiescent();
1407 break;
1408 }
1409 case LTTNG_DOMAIN_UST:
1410 {
1411 struct ltt_ust_session *usess;
1412
1413 usess = session->ust_session;
1414
1415 ret = trace_ust_track_pid(usess, pid);
1416 if (ret != LTTNG_OK) {
1417 goto error;
1418 }
1419 break;
1420 }
1421 default:
1422 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1423 goto error;
1424 }
1425
1426 ret = LTTNG_OK;
1427
1428 error:
1429 rcu_read_unlock();
1430 return ret;
1431 }
1432
1433 /*
1434 * Command LTTNG_UNTRACK_PID processed by the client thread.
1435 *
1436 * Called with session lock held.
1437 */
1438 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1439 int pid)
1440 {
1441 int ret;
1442
1443 rcu_read_lock();
1444
1445 switch (domain) {
1446 case LTTNG_DOMAIN_KERNEL:
1447 {
1448 struct ltt_kernel_session *ksess;
1449
1450 ksess = session->kernel_session;
1451
1452 ret = kernel_untrack_pid(ksess, pid);
1453 if (ret != LTTNG_OK) {
1454 goto error;
1455 }
1456
1457 kernel_wait_quiescent();
1458 break;
1459 }
1460 case LTTNG_DOMAIN_UST:
1461 {
1462 struct ltt_ust_session *usess;
1463
1464 usess = session->ust_session;
1465
1466 ret = trace_ust_untrack_pid(usess, pid);
1467 if (ret != LTTNG_OK) {
1468 goto error;
1469 }
1470 break;
1471 }
1472 default:
1473 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1474 goto error;
1475 }
1476
1477 ret = LTTNG_OK;
1478
1479 error:
1480 rcu_read_unlock();
1481 return ret;
1482 }
1483
1484 /*
1485 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1486 *
1487 * The wpipe arguments is used as a notifier for the kernel thread.
1488 */
1489 int cmd_enable_channel(struct ltt_session *session,
1490 const struct lttng_domain *domain, const struct lttng_channel *_attr, int wpipe)
1491 {
1492 int ret;
1493 struct ltt_ust_session *usess = session->ust_session;
1494 struct lttng_ht *chan_ht;
1495 size_t len;
1496 struct lttng_channel attr;
1497
1498 assert(session);
1499 assert(_attr);
1500 assert(domain);
1501
1502 attr = *_attr;
1503 len = lttng_strnlen(attr.name, sizeof(attr.name));
1504
1505 /* Validate channel name */
1506 if (attr.name[0] == '.' ||
1507 memchr(attr.name, '/', len) != NULL) {
1508 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1509 goto end;
1510 }
1511
1512 DBG("Enabling channel %s for session %s", attr.name, session->name);
1513
1514 rcu_read_lock();
1515
1516 /*
1517 * Don't try to enable a channel if the session has been started at
1518 * some point in time before. The tracer does not allow it.
1519 */
1520 if (session->has_been_started) {
1521 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1522 goto error;
1523 }
1524
1525 /*
1526 * If the session is a live session, remove the switch timer, the
1527 * live timer does the same thing but sends also synchronisation
1528 * beacons for inactive streams.
1529 */
1530 if (session->live_timer > 0) {
1531 attr.attr.live_timer_interval = session->live_timer;
1532 attr.attr.switch_timer_interval = 0;
1533 }
1534
1535 /* Check for feature support */
1536 switch (domain->type) {
1537 case LTTNG_DOMAIN_KERNEL:
1538 {
1539 if (kernel_supports_ring_buffer_snapshot_sample_positions() != 1) {
1540 /* Sampling position of buffer is not supported */
1541 WARN("Kernel tracer does not support buffer monitoring. "
1542 "Setting the monitor interval timer to 0 "
1543 "(disabled) for channel '%s' of session '%s'",
1544 attr.name, session->name);
1545 lttng_channel_set_monitor_timer_interval(&attr, 0);
1546 }
1547 break;
1548 }
1549 case LTTNG_DOMAIN_UST:
1550 break;
1551 case LTTNG_DOMAIN_JUL:
1552 case LTTNG_DOMAIN_LOG4J:
1553 case LTTNG_DOMAIN_PYTHON:
1554 if (!agent_tracing_is_enabled()) {
1555 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1556 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1557 goto error;
1558 }
1559 break;
1560 default:
1561 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1562 goto error;
1563 }
1564
1565 switch (domain->type) {
1566 case LTTNG_DOMAIN_KERNEL:
1567 {
1568 struct ltt_kernel_channel *kchan;
1569
1570 kchan = trace_kernel_get_channel_by_name(attr.name,
1571 session->kernel_session);
1572 if (kchan == NULL) {
1573 if (session->snapshot.nb_output > 0 ||
1574 session->snapshot_mode) {
1575 /* Enforce mmap output for snapshot sessions. */
1576 attr.attr.output = LTTNG_EVENT_MMAP;
1577 }
1578 ret = channel_kernel_create(session->kernel_session, &attr, wpipe);
1579 if (attr.name[0] != '\0') {
1580 session->kernel_session->has_non_default_channel = 1;
1581 }
1582 } else {
1583 ret = channel_kernel_enable(session->kernel_session, kchan);
1584 }
1585
1586 if (ret != LTTNG_OK) {
1587 goto error;
1588 }
1589
1590 kernel_wait_quiescent();
1591 break;
1592 }
1593 case LTTNG_DOMAIN_UST:
1594 case LTTNG_DOMAIN_JUL:
1595 case LTTNG_DOMAIN_LOG4J:
1596 case LTTNG_DOMAIN_PYTHON:
1597 {
1598 struct ltt_ust_channel *uchan;
1599
1600 /*
1601 * FIXME
1602 *
1603 * Current agent implementation limitations force us to allow
1604 * only one channel at once in "agent" subdomains. Each
1605 * subdomain has a default channel name which must be strictly
1606 * adhered to.
1607 */
1608 if (domain->type == LTTNG_DOMAIN_JUL) {
1609 if (strncmp(attr.name, DEFAULT_JUL_CHANNEL_NAME,
1610 LTTNG_SYMBOL_NAME_LEN)) {
1611 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1612 goto error;
1613 }
1614 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1615 if (strncmp(attr.name, DEFAULT_LOG4J_CHANNEL_NAME,
1616 LTTNG_SYMBOL_NAME_LEN)) {
1617 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1618 goto error;
1619 }
1620 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1621 if (strncmp(attr.name, DEFAULT_PYTHON_CHANNEL_NAME,
1622 LTTNG_SYMBOL_NAME_LEN)) {
1623 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1624 goto error;
1625 }
1626 }
1627
1628 chan_ht = usess->domain_global.channels;
1629
1630 uchan = trace_ust_find_channel_by_name(chan_ht, attr.name);
1631 if (uchan == NULL) {
1632 ret = channel_ust_create(usess, &attr, domain->buf_type);
1633 if (attr.name[0] != '\0') {
1634 usess->has_non_default_channel = 1;
1635 }
1636 } else {
1637 ret = channel_ust_enable(usess, uchan);
1638 }
1639 break;
1640 }
1641 default:
1642 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1643 goto error;
1644 }
1645
1646 if (ret == LTTNG_OK && attr.attr.output != LTTNG_EVENT_MMAP) {
1647 session->has_non_mmap_channel = true;
1648 }
1649 error:
1650 rcu_read_unlock();
1651 end:
1652 return ret;
1653 }
1654
1655 /*
1656 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1657 */
1658 int cmd_disable_event(struct ltt_session *session,
1659 enum lttng_domain_type domain, const char *channel_name,
1660 const struct lttng_event *event)
1661 {
1662 int ret;
1663 const char *event_name;
1664
1665 DBG("Disable event command for event \'%s\'", event->name);
1666
1667 event_name = event->name;
1668
1669 /* Error out on unhandled search criteria */
1670 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1671 || event->pid || event->filter || event->exclusion) {
1672 ret = LTTNG_ERR_UNK;
1673 goto error;
1674 }
1675
1676 rcu_read_lock();
1677
1678 switch (domain) {
1679 case LTTNG_DOMAIN_KERNEL:
1680 {
1681 struct ltt_kernel_channel *kchan;
1682 struct ltt_kernel_session *ksess;
1683
1684 ksess = session->kernel_session;
1685
1686 /*
1687 * If a non-default channel has been created in the
1688 * session, explicitely require that -c chan_name needs
1689 * to be provided.
1690 */
1691 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1692 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1693 goto error_unlock;
1694 }
1695
1696 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1697 if (kchan == NULL) {
1698 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1699 goto error_unlock;
1700 }
1701
1702 switch (event->type) {
1703 case LTTNG_EVENT_ALL:
1704 case LTTNG_EVENT_TRACEPOINT:
1705 case LTTNG_EVENT_SYSCALL:
1706 case LTTNG_EVENT_PROBE:
1707 case LTTNG_EVENT_FUNCTION:
1708 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1709 if (event_name[0] == '\0') {
1710 ret = event_kernel_disable_event(kchan,
1711 NULL, event->type);
1712 } else {
1713 ret = event_kernel_disable_event(kchan,
1714 event_name, event->type);
1715 }
1716 if (ret != LTTNG_OK) {
1717 goto error_unlock;
1718 }
1719 break;
1720 default:
1721 ret = LTTNG_ERR_UNK;
1722 goto error_unlock;
1723 }
1724
1725 kernel_wait_quiescent();
1726 break;
1727 }
1728 case LTTNG_DOMAIN_UST:
1729 {
1730 struct ltt_ust_channel *uchan;
1731 struct ltt_ust_session *usess;
1732
1733 usess = session->ust_session;
1734
1735 if (validate_ust_event_name(event_name)) {
1736 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1737 goto error_unlock;
1738 }
1739
1740 /*
1741 * If a non-default channel has been created in the
1742 * session, explicitly require that -c chan_name needs
1743 * to be provided.
1744 */
1745 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1746 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1747 goto error_unlock;
1748 }
1749
1750 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1751 channel_name);
1752 if (uchan == NULL) {
1753 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1754 goto error_unlock;
1755 }
1756
1757 switch (event->type) {
1758 case LTTNG_EVENT_ALL:
1759 /*
1760 * An empty event name means that everything
1761 * should be disabled.
1762 */
1763 if (event->name[0] == '\0') {
1764 ret = event_ust_disable_all_tracepoints(usess, uchan);
1765 } else {
1766 ret = event_ust_disable_tracepoint(usess, uchan,
1767 event_name);
1768 }
1769 if (ret != LTTNG_OK) {
1770 goto error_unlock;
1771 }
1772 break;
1773 default:
1774 ret = LTTNG_ERR_UNK;
1775 goto error_unlock;
1776 }
1777
1778 DBG3("Disable UST event %s in channel %s completed", event_name,
1779 channel_name);
1780 break;
1781 }
1782 case LTTNG_DOMAIN_LOG4J:
1783 case LTTNG_DOMAIN_JUL:
1784 case LTTNG_DOMAIN_PYTHON:
1785 {
1786 struct agent *agt;
1787 struct ltt_ust_session *usess = session->ust_session;
1788
1789 assert(usess);
1790
1791 switch (event->type) {
1792 case LTTNG_EVENT_ALL:
1793 break;
1794 default:
1795 ret = LTTNG_ERR_UNK;
1796 goto error_unlock;
1797 }
1798
1799 agt = trace_ust_find_agent(usess, domain);
1800 if (!agt) {
1801 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1802 goto error_unlock;
1803 }
1804 /*
1805 * An empty event name means that everything
1806 * should be disabled.
1807 */
1808 if (event->name[0] == '\0') {
1809 ret = event_agent_disable_all(usess, agt);
1810 } else {
1811 ret = event_agent_disable(usess, agt, event_name);
1812 }
1813 if (ret != LTTNG_OK) {
1814 goto error_unlock;
1815 }
1816
1817 break;
1818 }
1819 default:
1820 ret = LTTNG_ERR_UND;
1821 goto error_unlock;
1822 }
1823
1824 ret = LTTNG_OK;
1825
1826 error_unlock:
1827 rcu_read_unlock();
1828 error:
1829 return ret;
1830 }
1831
1832 /*
1833 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1834 */
1835 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1836 char *channel_name, const struct lttng_event_context *ctx, int kwpipe)
1837 {
1838 int ret, chan_kern_created = 0, chan_ust_created = 0;
1839 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1840
1841 /*
1842 * Don't try to add a context if the session has been started at
1843 * some point in time before. The tracer does not allow it and would
1844 * result in a corrupted trace.
1845 */
1846 if (session->has_been_started) {
1847 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1848 goto end;
1849 }
1850
1851 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1852 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1853 app_ctx_name = ctx->u.app_ctx.ctx_name;
1854 }
1855
1856 switch (domain) {
1857 case LTTNG_DOMAIN_KERNEL:
1858 assert(session->kernel_session);
1859
1860 if (session->kernel_session->channel_count == 0) {
1861 /* Create default channel */
1862 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1863 if (ret != LTTNG_OK) {
1864 goto error;
1865 }
1866 chan_kern_created = 1;
1867 }
1868 /* Add kernel context to kernel tracer */
1869 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1870 if (ret != LTTNG_OK) {
1871 goto error;
1872 }
1873 break;
1874 case LTTNG_DOMAIN_JUL:
1875 case LTTNG_DOMAIN_LOG4J:
1876 {
1877 /*
1878 * Validate channel name.
1879 * If no channel name is given and the domain is JUL or LOG4J,
1880 * set it to the appropriate domain-specific channel name. If
1881 * a name is provided but does not match the expexted channel
1882 * name, return an error.
1883 */
1884 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1885 strcmp(channel_name,
1886 DEFAULT_JUL_CHANNEL_NAME)) {
1887 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1888 goto error;
1889 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1890 strcmp(channel_name,
1891 DEFAULT_LOG4J_CHANNEL_NAME)) {
1892 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1893 goto error;
1894 }
1895 /* break is _not_ missing here. */
1896 }
1897 case LTTNG_DOMAIN_UST:
1898 {
1899 struct ltt_ust_session *usess = session->ust_session;
1900 unsigned int chan_count;
1901
1902 assert(usess);
1903
1904 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1905 if (chan_count == 0) {
1906 struct lttng_channel *attr;
1907 /* Create default channel */
1908 attr = channel_new_default_attr(domain, usess->buffer_type);
1909 if (attr == NULL) {
1910 ret = LTTNG_ERR_FATAL;
1911 goto error;
1912 }
1913
1914 ret = channel_ust_create(usess, attr, usess->buffer_type);
1915 if (ret != LTTNG_OK) {
1916 free(attr);
1917 goto error;
1918 }
1919 channel_attr_destroy(attr);
1920 chan_ust_created = 1;
1921 }
1922
1923 ret = context_ust_add(usess, domain, ctx, channel_name);
1924 free(app_ctx_provider_name);
1925 free(app_ctx_name);
1926 app_ctx_name = NULL;
1927 app_ctx_provider_name = NULL;
1928 if (ret != LTTNG_OK) {
1929 goto error;
1930 }
1931 break;
1932 }
1933 default:
1934 ret = LTTNG_ERR_UND;
1935 goto error;
1936 }
1937
1938 ret = LTTNG_OK;
1939 goto end;
1940
1941 error:
1942 if (chan_kern_created) {
1943 struct ltt_kernel_channel *kchan =
1944 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1945 session->kernel_session);
1946 /* Created previously, this should NOT fail. */
1947 assert(kchan);
1948 kernel_destroy_channel(kchan);
1949 }
1950
1951 if (chan_ust_created) {
1952 struct ltt_ust_channel *uchan =
1953 trace_ust_find_channel_by_name(
1954 session->ust_session->domain_global.channels,
1955 DEFAULT_CHANNEL_NAME);
1956 /* Created previously, this should NOT fail. */
1957 assert(uchan);
1958 /* Remove from the channel list of the session. */
1959 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1960 uchan);
1961 trace_ust_destroy_channel(uchan);
1962 }
1963 end:
1964 free(app_ctx_provider_name);
1965 free(app_ctx_name);
1966 return ret;
1967 }
1968
1969 static inline bool name_starts_with(const char *name, const char *prefix)
1970 {
1971 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1972
1973 return !strncmp(name, prefix, max_cmp_len);
1974 }
1975
1976 /* Perform userspace-specific event name validation */
1977 static int validate_ust_event_name(const char *name)
1978 {
1979 int ret = 0;
1980
1981 if (!name) {
1982 ret = -1;
1983 goto end;
1984 }
1985
1986 /*
1987 * Check name against all internal UST event component namespaces used
1988 * by the agents.
1989 */
1990 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1991 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1992 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1993 ret = -1;
1994 }
1995
1996 end:
1997 return ret;
1998 }
1999
2000 /*
2001 * Internal version of cmd_enable_event() with a supplemental
2002 * "internal_event" flag which is used to enable internal events which should
2003 * be hidden from clients. Such events are used in the agent implementation to
2004 * enable the events through which all "agent" events are funeled.
2005 */
2006 static int _cmd_enable_event(struct ltt_session *session,
2007 const struct lttng_domain *domain,
2008 char *channel_name, struct lttng_event *event,
2009 char *filter_expression,
2010 struct lttng_filter_bytecode *filter,
2011 struct lttng_event_exclusion *exclusion,
2012 int wpipe, bool internal_event)
2013 {
2014 int ret = 0, channel_created = 0;
2015 struct lttng_channel *attr = NULL;
2016
2017 assert(session);
2018 assert(event);
2019 assert(channel_name);
2020
2021 /* If we have a filter, we must have its filter expression */
2022 assert(!(!!filter_expression ^ !!filter));
2023
2024 /* Normalize event name as a globbing pattern */
2025 strutils_normalize_star_glob_pattern(event->name);
2026
2027 /* Normalize exclusion names as globbing patterns */
2028 if (exclusion) {
2029 size_t i;
2030
2031 for (i = 0; i < exclusion->count; i++) {
2032 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
2033
2034 strutils_normalize_star_glob_pattern(name);
2035 }
2036 }
2037
2038 DBG("Enable event command for event \'%s\'", event->name);
2039
2040 rcu_read_lock();
2041
2042 switch (domain->type) {
2043 case LTTNG_DOMAIN_KERNEL:
2044 {
2045 struct ltt_kernel_channel *kchan;
2046
2047 /*
2048 * If a non-default channel has been created in the
2049 * session, explicitely require that -c chan_name needs
2050 * to be provided.
2051 */
2052 if (session->kernel_session->has_non_default_channel
2053 && channel_name[0] == '\0') {
2054 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2055 goto error;
2056 }
2057
2058 kchan = trace_kernel_get_channel_by_name(channel_name,
2059 session->kernel_session);
2060 if (kchan == NULL) {
2061 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2062 LTTNG_BUFFER_GLOBAL);
2063 if (attr == NULL) {
2064 ret = LTTNG_ERR_FATAL;
2065 goto error;
2066 }
2067 if (lttng_strncpy(attr->name, channel_name,
2068 sizeof(attr->name))) {
2069 ret = LTTNG_ERR_INVALID;
2070 goto error;
2071 }
2072
2073 ret = cmd_enable_channel(session, domain, attr, wpipe);
2074 if (ret != LTTNG_OK) {
2075 goto error;
2076 }
2077 channel_created = 1;
2078 }
2079
2080 /* Get the newly created kernel channel pointer */
2081 kchan = trace_kernel_get_channel_by_name(channel_name,
2082 session->kernel_session);
2083 if (kchan == NULL) {
2084 /* This sould not happen... */
2085 ret = LTTNG_ERR_FATAL;
2086 goto error;
2087 }
2088
2089 switch (event->type) {
2090 case LTTNG_EVENT_ALL:
2091 {
2092 char *filter_expression_a = NULL;
2093 struct lttng_filter_bytecode *filter_a = NULL;
2094
2095 /*
2096 * We need to duplicate filter_expression and filter,
2097 * because ownership is passed to first enable
2098 * event.
2099 */
2100 if (filter_expression) {
2101 filter_expression_a = strdup(filter_expression);
2102 if (!filter_expression_a) {
2103 ret = LTTNG_ERR_FATAL;
2104 goto error;
2105 }
2106 }
2107 if (filter) {
2108 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2109 if (!filter_a) {
2110 free(filter_expression_a);
2111 ret = LTTNG_ERR_FATAL;
2112 goto error;
2113 }
2114 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2115 }
2116 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2117 ret = event_kernel_enable_event(kchan, event,
2118 filter_expression, filter);
2119 /* We have passed ownership */
2120 filter_expression = NULL;
2121 filter = NULL;
2122 if (ret != LTTNG_OK) {
2123 if (channel_created) {
2124 /* Let's not leak a useless channel. */
2125 kernel_destroy_channel(kchan);
2126 }
2127 free(filter_expression_a);
2128 free(filter_a);
2129 goto error;
2130 }
2131 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2132 ret = event_kernel_enable_event(kchan, event,
2133 filter_expression_a, filter_a);
2134 /* We have passed ownership */
2135 filter_expression_a = NULL;
2136 filter_a = NULL;
2137 if (ret != LTTNG_OK) {
2138 goto error;
2139 }
2140 break;
2141 }
2142 case LTTNG_EVENT_PROBE:
2143 case LTTNG_EVENT_USERSPACE_PROBE:
2144 case LTTNG_EVENT_FUNCTION:
2145 case LTTNG_EVENT_FUNCTION_ENTRY:
2146 case LTTNG_EVENT_TRACEPOINT:
2147 ret = event_kernel_enable_event(kchan, event,
2148 filter_expression, filter);
2149 /* We have passed ownership */
2150 filter_expression = NULL;
2151 filter = NULL;
2152 if (ret != LTTNG_OK) {
2153 if (channel_created) {
2154 /* Let's not leak a useless channel. */
2155 kernel_destroy_channel(kchan);
2156 }
2157 goto error;
2158 }
2159 break;
2160 case LTTNG_EVENT_SYSCALL:
2161 ret = event_kernel_enable_event(kchan, event,
2162 filter_expression, filter);
2163 /* We have passed ownership */
2164 filter_expression = NULL;
2165 filter = NULL;
2166 if (ret != LTTNG_OK) {
2167 goto error;
2168 }
2169 break;
2170 default:
2171 ret = LTTNG_ERR_UNK;
2172 goto error;
2173 }
2174
2175 kernel_wait_quiescent();
2176 break;
2177 }
2178 case LTTNG_DOMAIN_UST:
2179 {
2180 struct ltt_ust_channel *uchan;
2181 struct ltt_ust_session *usess = session->ust_session;
2182
2183 assert(usess);
2184
2185 /*
2186 * If a non-default channel has been created in the
2187 * session, explicitely require that -c chan_name needs
2188 * to be provided.
2189 */
2190 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2191 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2192 goto error;
2193 }
2194
2195 /* Get channel from global UST domain */
2196 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2197 channel_name);
2198 if (uchan == NULL) {
2199 /* Create default channel */
2200 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2201 usess->buffer_type);
2202 if (attr == NULL) {
2203 ret = LTTNG_ERR_FATAL;
2204 goto error;
2205 }
2206 if (lttng_strncpy(attr->name, channel_name,
2207 sizeof(attr->name))) {
2208 ret = LTTNG_ERR_INVALID;
2209 goto error;
2210 }
2211
2212 ret = cmd_enable_channel(session, domain, attr, wpipe);
2213 if (ret != LTTNG_OK) {
2214 goto error;
2215 }
2216
2217 /* Get the newly created channel reference back */
2218 uchan = trace_ust_find_channel_by_name(
2219 usess->domain_global.channels, channel_name);
2220 assert(uchan);
2221 }
2222
2223 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2224 /*
2225 * Don't allow users to add UST events to channels which
2226 * are assigned to a userspace subdomain (JUL, Log4J,
2227 * Python, etc.).
2228 */
2229 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2230 goto error;
2231 }
2232
2233 if (!internal_event) {
2234 /*
2235 * Ensure the event name is not reserved for internal
2236 * use.
2237 */
2238 ret = validate_ust_event_name(event->name);
2239 if (ret) {
2240 WARN("Userspace event name %s failed validation.",
2241 event->name);
2242 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2243 goto error;
2244 }
2245 }
2246
2247 /* At this point, the session and channel exist on the tracer */
2248 ret = event_ust_enable_tracepoint(usess, uchan, event,
2249 filter_expression, filter, exclusion,
2250 internal_event);
2251 /* We have passed ownership */
2252 filter_expression = NULL;
2253 filter = NULL;
2254 exclusion = NULL;
2255 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2256 goto already_enabled;
2257 } else if (ret != LTTNG_OK) {
2258 goto error;
2259 }
2260 break;
2261 }
2262 case LTTNG_DOMAIN_LOG4J:
2263 case LTTNG_DOMAIN_JUL:
2264 case LTTNG_DOMAIN_PYTHON:
2265 {
2266 const char *default_event_name, *default_chan_name;
2267 struct agent *agt;
2268 struct lttng_event uevent;
2269 struct lttng_domain tmp_dom;
2270 struct ltt_ust_session *usess = session->ust_session;
2271
2272 assert(usess);
2273
2274 if (!agent_tracing_is_enabled()) {
2275 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2276 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2277 goto error;
2278 }
2279
2280 agt = trace_ust_find_agent(usess, domain->type);
2281 if (!agt) {
2282 agt = agent_create(domain->type);
2283 if (!agt) {
2284 ret = LTTNG_ERR_NOMEM;
2285 goto error;
2286 }
2287 agent_add(agt, usess->agents);
2288 }
2289
2290 /* Create the default tracepoint. */
2291 memset(&uevent, 0, sizeof(uevent));
2292 uevent.type = LTTNG_EVENT_TRACEPOINT;
2293 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2294 default_event_name = event_get_default_agent_ust_name(
2295 domain->type);
2296 if (!default_event_name) {
2297 ret = LTTNG_ERR_FATAL;
2298 goto error;
2299 }
2300 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2301 uevent.name[sizeof(uevent.name) - 1] = '\0';
2302
2303 /*
2304 * The domain type is changed because we are about to enable the
2305 * default channel and event for the JUL domain that are hardcoded.
2306 * This happens in the UST domain.
2307 */
2308 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2309 tmp_dom.type = LTTNG_DOMAIN_UST;
2310
2311 switch (domain->type) {
2312 case LTTNG_DOMAIN_LOG4J:
2313 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2314 break;
2315 case LTTNG_DOMAIN_JUL:
2316 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2317 break;
2318 case LTTNG_DOMAIN_PYTHON:
2319 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2320 break;
2321 default:
2322 /* The switch/case we are in makes this impossible */
2323 assert(0);
2324 }
2325
2326 {
2327 char *filter_expression_copy = NULL;
2328 struct lttng_filter_bytecode *filter_copy = NULL;
2329
2330 if (filter) {
2331 const size_t filter_size = sizeof(
2332 struct lttng_filter_bytecode)
2333 + filter->len;
2334
2335 filter_copy = zmalloc(filter_size);
2336 if (!filter_copy) {
2337 ret = LTTNG_ERR_NOMEM;
2338 goto error;
2339 }
2340 memcpy(filter_copy, filter, filter_size);
2341
2342 filter_expression_copy =
2343 strdup(filter_expression);
2344 if (!filter_expression) {
2345 ret = LTTNG_ERR_NOMEM;
2346 }
2347
2348 if (!filter_expression_copy || !filter_copy) {
2349 free(filter_expression_copy);
2350 free(filter_copy);
2351 goto error;
2352 }
2353 }
2354
2355 ret = cmd_enable_event_internal(session, &tmp_dom,
2356 (char *) default_chan_name,
2357 &uevent, filter_expression_copy,
2358 filter_copy, NULL, wpipe);
2359 }
2360
2361 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2362 goto already_enabled;
2363 } else if (ret != LTTNG_OK) {
2364 goto error;
2365 }
2366
2367 /* The wild card * means that everything should be enabled. */
2368 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2369 ret = event_agent_enable_all(usess, agt, event, filter,
2370 filter_expression);
2371 } else {
2372 ret = event_agent_enable(usess, agt, event, filter,
2373 filter_expression);
2374 }
2375 filter = NULL;
2376 filter_expression = NULL;
2377 if (ret != LTTNG_OK) {
2378 goto error;
2379 }
2380
2381 break;
2382 }
2383 default:
2384 ret = LTTNG_ERR_UND;
2385 goto error;
2386 }
2387
2388 ret = LTTNG_OK;
2389
2390 already_enabled:
2391 error:
2392 free(filter_expression);
2393 free(filter);
2394 free(exclusion);
2395 channel_attr_destroy(attr);
2396 rcu_read_unlock();
2397 return ret;
2398 }
2399
2400 /*
2401 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2402 * We own filter, exclusion, and filter_expression.
2403 */
2404 int cmd_enable_event(struct ltt_session *session,
2405 const struct lttng_domain *domain,
2406 char *channel_name, struct lttng_event *event,
2407 char *filter_expression,
2408 struct lttng_filter_bytecode *filter,
2409 struct lttng_event_exclusion *exclusion,
2410 int wpipe)
2411 {
2412 return _cmd_enable_event(session, domain, channel_name, event,
2413 filter_expression, filter, exclusion, wpipe, false);
2414 }
2415
2416 /*
2417 * Enable an event which is internal to LTTng. An internal should
2418 * never be made visible to clients and are immune to checks such as
2419 * reserved names.
2420 */
2421 static int cmd_enable_event_internal(struct ltt_session *session,
2422 const struct lttng_domain *domain,
2423 char *channel_name, struct lttng_event *event,
2424 char *filter_expression,
2425 struct lttng_filter_bytecode *filter,
2426 struct lttng_event_exclusion *exclusion,
2427 int wpipe)
2428 {
2429 return _cmd_enable_event(session, domain, channel_name, event,
2430 filter_expression, filter, exclusion, wpipe, true);
2431 }
2432
2433 /*
2434 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2435 */
2436 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2437 struct lttng_event **events)
2438 {
2439 int ret;
2440 ssize_t nb_events = 0;
2441
2442 switch (domain) {
2443 case LTTNG_DOMAIN_KERNEL:
2444 nb_events = kernel_list_events(events);
2445 if (nb_events < 0) {
2446 ret = LTTNG_ERR_KERN_LIST_FAIL;
2447 goto error;
2448 }
2449 break;
2450 case LTTNG_DOMAIN_UST:
2451 nb_events = ust_app_list_events(events);
2452 if (nb_events < 0) {
2453 ret = LTTNG_ERR_UST_LIST_FAIL;
2454 goto error;
2455 }
2456 break;
2457 case LTTNG_DOMAIN_LOG4J:
2458 case LTTNG_DOMAIN_JUL:
2459 case LTTNG_DOMAIN_PYTHON:
2460 nb_events = agent_list_events(events, domain);
2461 if (nb_events < 0) {
2462 ret = LTTNG_ERR_UST_LIST_FAIL;
2463 goto error;
2464 }
2465 break;
2466 default:
2467 ret = LTTNG_ERR_UND;
2468 goto error;
2469 }
2470
2471 return nb_events;
2472
2473 error:
2474 /* Return negative value to differentiate return code */
2475 return -ret;
2476 }
2477
2478 /*
2479 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2480 */
2481 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2482 struct lttng_event_field **fields)
2483 {
2484 int ret;
2485 ssize_t nb_fields = 0;
2486
2487 switch (domain) {
2488 case LTTNG_DOMAIN_UST:
2489 nb_fields = ust_app_list_event_fields(fields);
2490 if (nb_fields < 0) {
2491 ret = LTTNG_ERR_UST_LIST_FAIL;
2492 goto error;
2493 }
2494 break;
2495 case LTTNG_DOMAIN_KERNEL:
2496 default: /* fall-through */
2497 ret = LTTNG_ERR_UND;
2498 goto error;
2499 }
2500
2501 return nb_fields;
2502
2503 error:
2504 /* Return negative value to differentiate return code */
2505 return -ret;
2506 }
2507
2508 ssize_t cmd_list_syscalls(struct lttng_event **events)
2509 {
2510 return syscall_table_list(events);
2511 }
2512
2513 /*
2514 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2515 *
2516 * Called with session lock held.
2517 */
2518 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2519 enum lttng_domain_type domain, int32_t **pids)
2520 {
2521 int ret;
2522 ssize_t nr_pids = 0;
2523
2524 switch (domain) {
2525 case LTTNG_DOMAIN_KERNEL:
2526 {
2527 struct ltt_kernel_session *ksess;
2528
2529 ksess = session->kernel_session;
2530 nr_pids = kernel_list_tracker_pids(ksess, pids);
2531 if (nr_pids < 0) {
2532 ret = LTTNG_ERR_KERN_LIST_FAIL;
2533 goto error;
2534 }
2535 break;
2536 }
2537 case LTTNG_DOMAIN_UST:
2538 {
2539 struct ltt_ust_session *usess;
2540
2541 usess = session->ust_session;
2542 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2543 if (nr_pids < 0) {
2544 ret = LTTNG_ERR_UST_LIST_FAIL;
2545 goto error;
2546 }
2547 break;
2548 }
2549 case LTTNG_DOMAIN_LOG4J:
2550 case LTTNG_DOMAIN_JUL:
2551 case LTTNG_DOMAIN_PYTHON:
2552 default:
2553 ret = LTTNG_ERR_UND;
2554 goto error;
2555 }
2556
2557 return nr_pids;
2558
2559 error:
2560 /* Return negative value to differentiate return code */
2561 return -ret;
2562 }
2563
2564 /*
2565 * Command LTTNG_START_TRACE processed by the client thread.
2566 *
2567 * Called with session mutex held.
2568 */
2569 int cmd_start_trace(struct ltt_session *session)
2570 {
2571 enum lttng_error_code ret;
2572 unsigned long nb_chan = 0;
2573 struct ltt_kernel_session *ksession;
2574 struct ltt_ust_session *usess;
2575
2576 assert(session);
2577
2578 /* Ease our life a bit ;) */
2579 ksession = session->kernel_session;
2580 usess = session->ust_session;
2581
2582 /* Is the session already started? */
2583 if (session->active) {
2584 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2585 goto error;
2586 }
2587
2588 /*
2589 * Starting a session without channel is useless since after that it's not
2590 * possible to enable channel thus inform the client.
2591 */
2592 if (usess && usess->domain_global.channels) {
2593 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2594 }
2595 if (ksession) {
2596 nb_chan += ksession->channel_count;
2597 }
2598 if (!nb_chan) {
2599 ret = LTTNG_ERR_NO_CHANNEL;
2600 goto error;
2601 }
2602
2603 if (session->output_traces && !session->current_trace_chunk) {
2604 struct lttng_trace_chunk *trace_chunk;
2605
2606 trace_chunk = session_create_new_trace_chunk(
2607 session, NULL, NULL, NULL);
2608 if (!trace_chunk) {
2609 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2610 goto error;
2611 }
2612 assert(!session->current_trace_chunk);
2613 ret = session_set_trace_chunk(session, trace_chunk, NULL);
2614 lttng_trace_chunk_put(trace_chunk);
2615 if (ret) {
2616 ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
2617 goto error;
2618 }
2619 }
2620
2621 /* Kernel tracing */
2622 if (ksession != NULL) {
2623 DBG("Start kernel tracing session %s", session->name);
2624 ret = start_kernel_session(ksession);
2625 if (ret != LTTNG_OK) {
2626 goto error;
2627 }
2628 }
2629
2630 /* Flag session that trace should start automatically */
2631 if (usess) {
2632 int int_ret = ust_app_start_trace_all(usess);
2633
2634 if (int_ret < 0) {
2635 ret = LTTNG_ERR_UST_START_FAIL;
2636 goto error;
2637 }
2638 }
2639
2640 /* Flag this after a successful start. */
2641 session->has_been_started = 1;
2642 session->active = 1;
2643
2644 /*
2645 * Clear the flag that indicates that a rotation was done while the
2646 * session was stopped.
2647 */
2648 session->rotated_after_last_stop = false;
2649
2650 if (session->rotate_timer_period) {
2651 int int_ret = timer_session_rotation_schedule_timer_start(
2652 session, session->rotate_timer_period);
2653
2654 if (int_ret < 0) {
2655 ERR("Failed to enable rotate timer");
2656 ret = LTTNG_ERR_UNK;
2657 goto error;
2658 }
2659 }
2660
2661 ret = LTTNG_OK;
2662
2663 error:
2664 return ret;
2665 }
2666
2667 /*
2668 * Command LTTNG_STOP_TRACE processed by the client thread.
2669 */
2670 int cmd_stop_trace(struct ltt_session *session)
2671 {
2672 int ret;
2673 struct ltt_kernel_channel *kchan;
2674 struct ltt_kernel_session *ksession;
2675 struct ltt_ust_session *usess;
2676 bool error_occurred = false;
2677
2678 assert(session);
2679
2680 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2681 /* Short cut */
2682 ksession = session->kernel_session;
2683 usess = session->ust_session;
2684
2685 /* Session is not active. Skip everythong and inform the client. */
2686 if (!session->active) {
2687 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2688 goto error;
2689 }
2690
2691 /* Kernel tracer */
2692 if (ksession && ksession->active) {
2693 DBG("Stop kernel tracing");
2694
2695 ret = kernel_stop_session(ksession);
2696 if (ret < 0) {
2697 ret = LTTNG_ERR_KERN_STOP_FAIL;
2698 goto error;
2699 }
2700
2701 kernel_wait_quiescent();
2702
2703 /* Flush metadata after stopping (if exists) */
2704 if (ksession->metadata_stream_fd >= 0) {
2705 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2706 if (ret < 0) {
2707 ERR("Kernel metadata flush failed");
2708 error_occurred = true;
2709 }
2710 }
2711
2712 /* Flush all buffers after stopping */
2713 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2714 ret = kernel_flush_buffer(kchan);
2715 if (ret < 0) {
2716 ERR("Kernel flush buffer error");
2717 error_occurred = true;
2718 }
2719 }
2720
2721 ksession->active = 0;
2722 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2723 session->id);
2724 }
2725
2726 if (usess && usess->active) {
2727 ret = ust_app_stop_trace_all(usess);
2728 if (ret < 0) {
2729 ret = LTTNG_ERR_UST_STOP_FAIL;
2730 goto error;
2731 }
2732 }
2733
2734 /* Flag inactive after a successful stop. */
2735 session->active = 0;
2736 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2737
2738 error:
2739 return ret;
2740 }
2741
2742 /*
2743 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2744 */
2745 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2746 struct lttng_uri *uris)
2747 {
2748 int ret, i;
2749 struct ltt_kernel_session *ksess = session->kernel_session;
2750 struct ltt_ust_session *usess = session->ust_session;
2751
2752 assert(session);
2753 assert(uris);
2754 assert(nb_uri > 0);
2755
2756 /* Can't set consumer URI if the session is active. */
2757 if (session->active) {
2758 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2759 goto error;
2760 }
2761
2762 for (i = 0; i < nb_uri; i++) {
2763 if (uris[i].stype != LTTNG_STREAM_CONTROL ||
2764 uris[i].subdir[0] == '\0') {
2765 /* Not interested in these URIs */
2766 continue;
2767 }
2768
2769 if (session->base_path != NULL) {
2770 free(session->base_path);
2771 session->base_path = NULL;
2772 }
2773
2774 /* Set session base_path */
2775 session->base_path = strdup(uris[i].subdir);
2776 if (!session->base_path) {
2777 PERROR("Copying base path: %s", uris[i].subdir);
2778 goto error;
2779 }
2780 DBG2("Setting base path for session %" PRIu64 ": %s",
2781 session->id, session->base_path);
2782 }
2783
2784 /* Set the "global" consumer URIs */
2785 for (i = 0; i < nb_uri; i++) {
2786 ret = add_uri_to_consumer(session, session->consumer, &uris[i],
2787 LTTNG_DOMAIN_NONE);
2788 if (ret != LTTNG_OK) {
2789 goto error;
2790 }
2791 }
2792
2793 /* Set UST session URIs */
2794 if (session->ust_session) {
2795 for (i = 0; i < nb_uri; i++) {
2796 ret = add_uri_to_consumer(session,
2797 session->ust_session->consumer,
2798 &uris[i], LTTNG_DOMAIN_UST);
2799 if (ret != LTTNG_OK) {
2800 goto error;
2801 }
2802 }
2803 }
2804
2805 /* Set kernel session URIs */
2806 if (session->kernel_session) {
2807 for (i = 0; i < nb_uri; i++) {
2808 ret = add_uri_to_consumer(session,
2809 session->kernel_session->consumer,
2810 &uris[i], LTTNG_DOMAIN_KERNEL);
2811 if (ret != LTTNG_OK) {
2812 goto error;
2813 }
2814 }
2815 }
2816
2817 /*
2818 * Make sure to set the session in output mode after we set URI since a
2819 * session can be created without URL (thus flagged in no output mode).
2820 */
2821 session->output_traces = 1;
2822 if (ksess) {
2823 ksess->output_traces = 1;
2824 }
2825
2826 if (usess) {
2827 usess->output_traces = 1;
2828 }
2829
2830 /* All good! */
2831 ret = LTTNG_OK;
2832
2833 error:
2834 return ret;
2835 }
2836
2837 static
2838 enum lttng_error_code set_session_output_from_descriptor(
2839 struct ltt_session *session,
2840 const struct lttng_session_descriptor *descriptor)
2841 {
2842 int ret;
2843 enum lttng_error_code ret_code = LTTNG_OK;
2844 enum lttng_session_descriptor_type session_type =
2845 lttng_session_descriptor_get_type(descriptor);
2846 enum lttng_session_descriptor_output_type output_type =
2847 lttng_session_descriptor_get_output_type(descriptor);
2848 struct lttng_uri uris[2] = {};
2849 size_t uri_count = 0;
2850
2851 switch (output_type) {
2852 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NONE:
2853 goto end;
2854 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_LOCAL:
2855 lttng_session_descriptor_get_local_output_uri(descriptor,
2856 &uris[0]);
2857 uri_count = 1;
2858 break;
2859 case LTTNG_SESSION_DESCRIPTOR_OUTPUT_TYPE_NETWORK:
2860 lttng_session_descriptor_get_network_output_uris(descriptor,
2861 &uris[0], &uris[1]);
2862 uri_count = 2;
2863 break;
2864 default:
2865 ret_code = LTTNG_ERR_INVALID;
2866 goto end;
2867 }
2868
2869 switch (session_type) {
2870 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2871 {
2872 struct snapshot_output *new_output = NULL;
2873
2874 new_output = snapshot_output_alloc();
2875 if (!new_output) {
2876 ret_code = LTTNG_ERR_NOMEM;
2877 goto end;
2878 }
2879
2880 ret = snapshot_output_init_with_uri(session,
2881 DEFAULT_SNAPSHOT_MAX_SIZE,
2882 NULL, uris, uri_count, session->consumer,
2883 new_output, &session->snapshot);
2884 if (ret < 0) {
2885 ret_code = (ret == -ENOMEM) ?
2886 LTTNG_ERR_NOMEM : LTTNG_ERR_INVALID;
2887 snapshot_output_destroy(new_output);
2888 goto end;
2889 }
2890 snapshot_add_output(&session->snapshot, new_output);
2891 break;
2892 }
2893 case LTTNG_SESSION_DESCRIPTOR_TYPE_REGULAR:
2894 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2895 {
2896 ret_code = cmd_set_consumer_uri(session, uri_count, uris);
2897 break;
2898 }
2899 default:
2900 ret_code = LTTNG_ERR_INVALID;
2901 goto end;
2902 }
2903 end:
2904 return ret_code;
2905 }
2906
2907 static
2908 enum lttng_error_code cmd_create_session_from_descriptor(
2909 struct lttng_session_descriptor *descriptor,
2910 const lttng_sock_cred *creds,
2911 const char *home_path)
2912 {
2913 int ret;
2914 enum lttng_error_code ret_code;
2915 const char *session_name;
2916 struct ltt_session *new_session = NULL;
2917 enum lttng_session_descriptor_status descriptor_status;
2918
2919 session_lock_list();
2920 if (home_path) {
2921 if (*home_path != '/') {
2922 ERR("Home path provided by client is not absolute");
2923 ret_code = LTTNG_ERR_INVALID;
2924 goto end;
2925 }
2926 }
2927
2928 descriptor_status = lttng_session_descriptor_get_session_name(
2929 descriptor, &session_name);
2930 switch (descriptor_status) {
2931 case LTTNG_SESSION_DESCRIPTOR_STATUS_OK:
2932 break;
2933 case LTTNG_SESSION_DESCRIPTOR_STATUS_UNSET:
2934 session_name = NULL;
2935 break;
2936 default:
2937 ret_code = LTTNG_ERR_INVALID;
2938 goto end;
2939 }
2940
2941 ret_code = session_create(session_name, creds->uid, creds->gid,
2942 &new_session);
2943 if (ret_code != LTTNG_OK) {
2944 goto end;
2945 }
2946
2947 if (!session_name) {
2948 ret = lttng_session_descriptor_set_session_name(descriptor,
2949 new_session->name);
2950 if (ret) {
2951 ret_code = LTTNG_ERR_SESSION_FAIL;
2952 goto end;
2953 }
2954 }
2955
2956 if (!lttng_session_descriptor_is_output_destination_initialized(
2957 descriptor)) {
2958 /*
2959 * Only include the session's creation time in the output
2960 * destination if the name of the session itself was
2961 * not auto-generated.
2962 */
2963 ret_code = lttng_session_descriptor_set_default_output(
2964 descriptor,
2965 session_name ? &new_session->creation_time : NULL,
2966 home_path);
2967 if (ret_code != LTTNG_OK) {
2968 goto end;
2969 }
2970 } else {
2971 new_session->has_user_specified_directory =
2972 lttng_session_descriptor_has_output_directory(
2973 descriptor);
2974 }
2975
2976 switch (lttng_session_descriptor_get_type(descriptor)) {
2977 case LTTNG_SESSION_DESCRIPTOR_TYPE_SNAPSHOT:
2978 new_session->snapshot_mode = 1;
2979 break;
2980 case LTTNG_SESSION_DESCRIPTOR_TYPE_LIVE:
2981 new_session->live_timer =
2982 lttng_session_descriptor_live_get_timer_interval(
2983 descriptor);
2984 break;
2985 default:
2986 break;
2987 }
2988
2989 ret_code = set_session_output_from_descriptor(new_session, descriptor);
2990 if (ret_code != LTTNG_OK) {
2991 goto end;
2992 }
2993 new_session->consumer->enabled = 1;
2994 ret_code = LTTNG_OK;
2995 end:
2996 /* Release reference provided by the session_create function. */
2997 session_put(new_session);
2998 if (ret_code != LTTNG_OK && new_session) {
2999 /* Release the global reference on error. */
3000 session_destroy(new_session);
3001 }
3002 session_unlock_list();
3003 return ret_code;
3004 }
3005
3006 enum lttng_error_code cmd_create_session(struct command_ctx *cmd_ctx, int sock,
3007 struct lttng_session_descriptor **return_descriptor)
3008 {
3009 int ret;
3010 size_t payload_size;
3011 struct lttng_dynamic_buffer payload;
3012 struct lttng_buffer_view home_dir_view;
3013 struct lttng_buffer_view session_descriptor_view;
3014 struct lttng_session_descriptor *session_descriptor = NULL;
3015 enum lttng_error_code ret_code;
3016
3017 lttng_dynamic_buffer_init(&payload);
3018 if (cmd_ctx->lsm->u.create_session.home_dir_size >=
3019 LTTNG_PATH_MAX) {
3020 ret_code = LTTNG_ERR_INVALID;
3021 goto error;
3022 }
3023 if (cmd_ctx->lsm->u.create_session.session_descriptor_size >
3024 LTTNG_SESSION_DESCRIPTOR_MAX_LEN) {
3025 ret_code = LTTNG_ERR_INVALID;
3026 goto error;
3027 }
3028
3029 payload_size = cmd_ctx->lsm->u.create_session.home_dir_size +
3030 cmd_ctx->lsm->u.create_session.session_descriptor_size;
3031 ret = lttng_dynamic_buffer_set_size(&payload, payload_size);
3032 if (ret) {
3033 ret_code = LTTNG_ERR_NOMEM;
3034 goto error;
3035 }
3036
3037 ret = lttcomm_recv_unix_sock(sock, payload.data, payload.size);
3038 if (ret <= 0) {
3039 ERR("Reception of session descriptor failed, aborting.");
3040 ret_code = LTTNG_ERR_SESSION_FAIL;
3041 goto error;
3042 }
3043
3044 home_dir_view = lttng_buffer_view_from_dynamic_buffer(
3045 &payload,
3046 0,
3047 cmd_ctx->lsm->u.create_session.home_dir_size);
3048 session_descriptor_view = lttng_buffer_view_from_dynamic_buffer(
3049 &payload,
3050 cmd_ctx->lsm->u.create_session.home_dir_size,
3051 cmd_ctx->lsm->u.create_session.session_descriptor_size);
3052
3053 ret = lttng_session_descriptor_create_from_buffer(
3054 &session_descriptor_view, &session_descriptor);
3055 if (ret < 0) {
3056 ERR("Failed to create session descriptor from payload of \"create session\" command");
3057 ret_code = LTTNG_ERR_INVALID;
3058 goto error;
3059 }
3060
3061 /*
3062 * Sets the descriptor's auto-generated properties (name, output) if
3063 * needed.
3064 */
3065 ret_code = cmd_create_session_from_descriptor(session_descriptor,
3066 &cmd_ctx->creds,
3067 home_dir_view.size ? home_dir_view.data : NULL);
3068 if (ret_code != LTTNG_OK) {
3069 goto error;
3070 }
3071
3072 ret_code = LTTNG_OK;
3073 *return_descriptor = session_descriptor;
3074 session_descriptor = NULL;
3075 error:
3076 lttng_dynamic_buffer_reset(&payload);
3077 lttng_session_descriptor_destroy(session_descriptor);
3078 return ret_code;
3079 }
3080
3081 static
3082 void cmd_destroy_session_reply(const struct ltt_session *session,
3083 void *_reply_context)
3084 {
3085 int ret;
3086 ssize_t comm_ret;
3087 const struct cmd_destroy_session_reply_context *reply_context =
3088 _reply_context;
3089 struct lttng_dynamic_buffer payload;
3090 struct lttcomm_session_destroy_command_header cmd_header;
3091 struct lttng_trace_archive_location *location = NULL;
3092 struct lttcomm_lttng_msg llm = {
3093 .cmd_type = LTTNG_DESTROY_SESSION,
3094 .ret_code = reply_context->destruction_status,
3095 .pid = UINT32_MAX,
3096 .cmd_header_size =
3097 sizeof(struct lttcomm_session_destroy_command_header),
3098 .data_size = 0,
3099 };
3100 size_t payload_size_before_location;
3101
3102 lttng_dynamic_buffer_init(&payload);
3103
3104 ret = lttng_dynamic_buffer_append(&payload, &llm, sizeof(llm));
3105 if (ret) {
3106 ERR("Failed to append session destruction message");
3107 goto error;
3108 }
3109
3110 cmd_header.rotation_state =
3111 (int32_t) (reply_context->implicit_rotation_on_destroy ?
3112 session->rotation_state :
3113 LTTNG_ROTATION_STATE_NO_ROTATION);
3114 ret = lttng_dynamic_buffer_append(&payload, &cmd_header,
3115 sizeof(cmd_header));
3116 if (ret) {
3117 ERR("Failed to append session destruction command header");
3118 goto error;
3119 }
3120
3121 if (!reply_context->implicit_rotation_on_destroy) {
3122 DBG("No implicit rotation performed during the destruction of session \"%s\", sending reply",
3123 session->name);
3124 goto send_reply;
3125 }
3126 if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
3127 DBG("Rotation state of session \"%s\" is not \"completed\", sending session destruction reply",
3128 session->name);
3129 goto send_reply;
3130 }
3131
3132 location = session_get_trace_archive_location(session);
3133 if (!location) {
3134 ERR("Failed to get the location of the trace archive produced during the destruction of session \"%s\"",
3135 session->name);
3136 goto error;
3137 }
3138
3139 payload_size_before_location = payload.size;
3140 comm_ret = lttng_trace_archive_location_serialize(location,
3141 &payload);
3142 if (comm_ret < 0) {
3143 ERR("Failed to serialize the location of the trace archive produced during the destruction of session \"%s\"",
3144 session->name);
3145 goto error;
3146 }
3147 /* Update the message to indicate the location's length. */
3148 ((struct lttcomm_lttng_msg *) payload.data)->data_size =
3149 payload.size - payload_size_before_location;
3150 send_reply:
3151 comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd,
3152 payload.data, payload.size);
3153 if (comm_ret != (ssize_t) payload.size) {
3154 ERR("Failed to send result of the destruction of session \"%s\" to client",
3155 session->name);
3156 }
3157 error:
3158 ret = close(reply_context->reply_sock_fd);
3159 if (ret) {
3160 PERROR("Failed to close client socket in deferred session destroy reply");
3161 }
3162 lttng_dynamic_buffer_reset(&payload);
3163 free(_reply_context);
3164 }
3165
3166 /*
3167 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3168 *
3169 * Called with session lock held.
3170 */
3171 int cmd_destroy_session(struct ltt_session *session,
3172 struct notification_thread_handle *notification_thread_handle,
3173 int *sock_fd)
3174 {
3175 int ret;
3176 enum lttng_error_code destruction_last_error = LTTNG_OK;
3177 struct cmd_destroy_session_reply_context *reply_context = NULL;
3178
3179 if (sock_fd) {
3180 reply_context = zmalloc(sizeof(*reply_context));
3181 if (!reply_context) {
3182 ret = LTTNG_ERR_NOMEM;
3183 goto end;
3184 }
3185 reply_context->reply_sock_fd = *sock_fd;
3186 }
3187
3188 /* Safety net */
3189 assert(session);
3190
3191 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name,
3192 session->id);
3193 if (session->active) {
3194 DBG("Session \"%s\" is active, attempting to stop it before destroying it",
3195 session->name);
3196 ret = cmd_stop_trace(session);
3197 if (ret != LTTNG_OK && ret != LTTNG_ERR_TRACE_ALREADY_STOPPED) {
3198 /* Carry on with the destruction of the session. */
3199 ERR("Failed to stop session \"%s\" as part of its destruction: %s",
3200 session->name, lttng_strerror(-ret));
3201 destruction_last_error = ret;
3202 }
3203 }
3204
3205 if (session->rotation_schedule_timer_enabled) {
3206 if (timer_session_rotation_schedule_timer_stop(
3207 session)) {
3208 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3209 session->name);
3210 destruction_last_error = LTTNG_ERR_TIMER_STOP_ERROR;
3211 }
3212 }
3213
3214 if (session->rotate_size) {
3215 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3216 session->rotate_size = 0;
3217 }
3218
3219 if (session->most_recent_chunk_id.is_set &&
3220 session->most_recent_chunk_id.value != 0 &&
3221 session->current_trace_chunk && session->output_traces) {
3222 /*
3223 * Perform a last rotation on destruction if rotations have
3224 * occurred during the session's lifetime.
3225 */
3226 ret = cmd_rotate_session(session, NULL, false);
3227 if (ret != LTTNG_OK) {
3228 ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
3229 session->name, lttng_strerror(-ret));
3230 destruction_last_error = -ret;
3231 }
3232 if (reply_context) {
3233 reply_context->implicit_rotation_on_destroy = true;
3234 }
3235 } else if (session->has_been_started && session->current_trace_chunk) {
3236 /*
3237 * The user has not triggered a session rotation. However, to
3238 * ensure all data has been consumed, the session is rotated
3239 * to a 'null' trace chunk before it is destroyed.
3240 *
3241 * This is a "quiet" rotation meaning that no notification is
3242 * emitted and no renaming of the current trace chunk takes
3243 * place.
3244 */
3245 ret = cmd_rotate_session(session, NULL, true);
3246 if (ret != LTTNG_OK) {
3247 ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
3248 session->name, lttng_strerror(-ret));
3249 destruction_last_error = -ret;
3250 }
3251 }
3252
3253 if (session->shm_path[0]) {
3254 /*
3255 * When a session is created with an explicit shm_path,
3256 * the consumer daemon will create its shared memory files
3257 * at that location and will *not* unlink them. This is normal
3258 * as the intention of that feature is to make it possible
3259 * to retrieve the content of those files should a crash occur.
3260 *
3261 * To ensure the content of those files can be used, the
3262 * sessiond daemon will replicate the content of the metadata
3263 * cache in a metadata file.
3264 *
3265 * On clean-up, it is expected that the consumer daemon will
3266 * unlink the shared memory files and that the session daemon
3267 * will unlink the metadata file. Then, the session's directory
3268 * in the shm path can be removed.
3269 *
3270 * Unfortunately, a flaw in the design of the sessiond's and
3271 * consumerd's tear down of channels makes it impossible to
3272 * determine when the sessiond _and_ the consumerd have both
3273 * destroyed their representation of a channel. For one, the
3274 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3275 * callbacks in both daemons.
3276 *
3277 * However, it is also impossible for the sessiond to know when
3278 * the consumer daemon is done destroying its channel(s) since
3279 * it occurs as a reaction to the closing of the channel's file
3280 * descriptor. There is no resulting communication initiated
3281 * from the consumerd to the sessiond to confirm that the
3282 * operation is completed (and was successful).
3283 *
3284 * Until this is all fixed, the session daemon checks for the
3285 * removal of the session's shm path which makes it possible
3286 * to safely advertise a session as having been destroyed.
3287 *
3288 * Prior to this fix, it was not possible to reliably save
3289 * a session making use of the --shm-path option, destroy it,
3290 * and load it again. This is because the creation of the
3291 * session would fail upon seeing the session's shm path
3292 * already in existence.
3293 *
3294 * Note that none of the error paths in the check for the
3295 * directory's existence return an error. This is normal
3296 * as there isn't much that can be done. The session will
3297 * be destroyed properly, except that we can't offer the
3298 * guarantee that the same session can be re-created.
3299 */
3300 current_completion_handler = &destroy_completion_handler.handler;
3301 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3302 session->shm_path,
3303 sizeof(destroy_completion_handler.shm_path));
3304 assert(!ret);
3305 }
3306
3307 /*
3308 * The session is destroyed. However, note that the command context
3309 * still holds a reference to the session, thus delaying its destruction
3310 * _at least_ up to the point when that reference is released.
3311 */
3312 session_destroy(session);
3313 if (reply_context) {
3314 reply_context->destruction_status = destruction_last_error;
3315 ret = session_add_destroy_notifier(session,
3316 cmd_destroy_session_reply,
3317 (void *) reply_context);
3318 if (ret) {
3319 ret = LTTNG_ERR_FATAL;
3320 goto end;
3321 } else {
3322 *sock_fd = -1;
3323 }
3324 }
3325 ret = LTTNG_OK;
3326 end:
3327 return ret;
3328 }
3329
3330 /*
3331 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3332 */
3333 int cmd_register_consumer(struct ltt_session *session,
3334 enum lttng_domain_type domain, const char *sock_path,
3335 struct consumer_data *cdata)
3336 {
3337 int ret, sock;
3338 struct consumer_socket *socket = NULL;
3339
3340 assert(session);
3341 assert(cdata);
3342 assert(sock_path);
3343
3344 switch (domain) {
3345 case LTTNG_DOMAIN_KERNEL:
3346 {
3347 struct ltt_kernel_session *ksess = session->kernel_session;
3348
3349 assert(ksess);
3350
3351 /* Can't register a consumer if there is already one */
3352 if (ksess->consumer_fds_sent != 0) {
3353 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3354 goto error;
3355 }
3356
3357 sock = lttcomm_connect_unix_sock(sock_path);
3358 if (sock < 0) {
3359 ret = LTTNG_ERR_CONNECT_FAIL;
3360 goto error;
3361 }
3362 cdata->cmd_sock = sock;
3363
3364 socket = consumer_allocate_socket(&cdata->cmd_sock);
3365 if (socket == NULL) {
3366 ret = close(sock);
3367 if (ret < 0) {
3368 PERROR("close register consumer");
3369 }
3370 cdata->cmd_sock = -1;
3371 ret = LTTNG_ERR_FATAL;
3372 goto error;
3373 }
3374
3375 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3376 if (socket->lock == NULL) {
3377 PERROR("zmalloc pthread mutex");
3378 ret = LTTNG_ERR_FATAL;
3379 goto error;
3380 }
3381 pthread_mutex_init(socket->lock, NULL);
3382 socket->registered = 1;
3383
3384 rcu_read_lock();
3385 consumer_add_socket(socket, ksess->consumer);
3386 rcu_read_unlock();
3387
3388 pthread_mutex_lock(&cdata->pid_mutex);
3389 cdata->pid = -1;
3390 pthread_mutex_unlock(&cdata->pid_mutex);
3391
3392 break;
3393 }
3394 default:
3395 /* TODO: Userspace tracing */
3396 ret = LTTNG_ERR_UND;
3397 goto error;
3398 }
3399
3400 return LTTNG_OK;
3401
3402 error:
3403 if (socket) {
3404 consumer_destroy_socket(socket);
3405 }
3406 return ret;
3407 }
3408
3409 /*
3410 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3411 */
3412 ssize_t cmd_list_domains(struct ltt_session *session,
3413 struct lttng_domain **domains)
3414 {
3415 int ret, index = 0;
3416 ssize_t nb_dom = 0;
3417 struct agent *agt;
3418 struct lttng_ht_iter iter;
3419
3420 if (session->kernel_session != NULL) {
3421 DBG3("Listing domains found kernel domain");
3422 nb_dom++;
3423 }
3424
3425 if (session->ust_session != NULL) {
3426 DBG3("Listing domains found UST global domain");
3427 nb_dom++;
3428
3429 rcu_read_lock();
3430 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3431 agt, node.node) {
3432 if (agt->being_used) {
3433 nb_dom++;
3434 }
3435 }
3436 rcu_read_unlock();
3437 }
3438
3439 if (!nb_dom) {
3440 goto end;
3441 }
3442
3443 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3444 if (*domains == NULL) {
3445 ret = LTTNG_ERR_FATAL;
3446 goto error;
3447 }
3448
3449 if (session->kernel_session != NULL) {
3450 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3451
3452 /* Kernel session buffer type is always GLOBAL */
3453 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3454
3455 index++;
3456 }
3457
3458 if (session->ust_session != NULL) {
3459 (*domains)[index].type = LTTNG_DOMAIN_UST;
3460 (*domains)[index].buf_type = session->ust_session->buffer_type;
3461 index++;
3462
3463 rcu_read_lock();
3464 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3465 agt, node.node) {
3466 if (agt->being_used) {
3467 (*domains)[index].type = agt->domain;
3468 (*domains)[index].buf_type = session->ust_session->buffer_type;
3469 index++;
3470 }
3471 }
3472 rcu_read_unlock();
3473 }
3474 end:
3475 return nb_dom;
3476
3477 error:
3478 /* Return negative value to differentiate return code */
3479 return -ret;
3480 }
3481
3482
3483 /*
3484 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3485 */
3486 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3487 struct ltt_session *session, struct lttng_channel **channels)
3488 {
3489 ssize_t nb_chan = 0, payload_size = 0, ret;
3490
3491 switch (domain) {
3492 case LTTNG_DOMAIN_KERNEL:
3493 if (session->kernel_session != NULL) {
3494 nb_chan = session->kernel_session->channel_count;
3495 }
3496 DBG3("Number of kernel channels %zd", nb_chan);
3497 if (nb_chan <= 0) {
3498 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3499 goto end;
3500 }
3501 break;
3502 case LTTNG_DOMAIN_UST:
3503 if (session->ust_session != NULL) {
3504 rcu_read_lock();
3505 nb_chan = lttng_ht_get_count(
3506 session->ust_session->domain_global.channels);
3507 rcu_read_unlock();
3508 }
3509 DBG3("Number of UST global channels %zd", nb_chan);
3510 if (nb_chan < 0) {
3511 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3512 goto end;
3513 }
3514 break;
3515 default:
3516 ret = -LTTNG_ERR_UND;
3517 goto end;
3518 }
3519
3520 if (nb_chan > 0) {
3521 const size_t channel_size = sizeof(struct lttng_channel) +
3522 sizeof(struct lttng_channel_extended);
3523 struct lttng_channel_extended *channel_exts;
3524
3525 payload_size = nb_chan * channel_size;
3526 *channels = zmalloc(payload_size);
3527 if (*channels == NULL) {
3528 ret = -LTTNG_ERR_FATAL;
3529 goto end;
3530 }
3531
3532 channel_exts = ((void *) *channels) +
3533 (nb_chan * sizeof(struct lttng_channel));
3534 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3535 if (ret != LTTNG_OK) {
3536 free(*channels);
3537 *channels = NULL;
3538 goto end;
3539 }
3540 } else {
3541 *channels = NULL;
3542 }
3543
3544 ret = payload_size;
3545 end:
3546 return ret;
3547 }
3548
3549 /*
3550 * Command LTTNG_LIST_EVENTS processed by the client thread.
3551 */
3552 ssize_t cmd_list_events(enum lttng_domain_type domain,
3553 struct ltt_session *session, char *channel_name,
3554 struct lttng_event **events, size_t *total_size)
3555 {
3556 int ret = 0;
3557 ssize_t nb_event = 0;
3558
3559 switch (domain) {
3560 case LTTNG_DOMAIN_KERNEL:
3561 if (session->kernel_session != NULL) {
3562 nb_event = list_lttng_kernel_events(channel_name,
3563 session->kernel_session, events,
3564 total_size);
3565 }
3566 break;
3567 case LTTNG_DOMAIN_UST:
3568 {
3569 if (session->ust_session != NULL) {
3570 nb_event = list_lttng_ust_global_events(channel_name,
3571 &session->ust_session->domain_global, events,
3572 total_size);
3573 }
3574 break;
3575 }
3576 case LTTNG_DOMAIN_LOG4J:
3577 case LTTNG_DOMAIN_JUL:
3578 case LTTNG_DOMAIN_PYTHON:
3579 if (session->ust_session) {
3580 struct lttng_ht_iter iter;
3581 struct agent *agt;
3582
3583 rcu_read_lock();
3584 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3585 &iter.iter, agt, node.node) {
3586 if (agt->domain == domain) {
3587 nb_event = list_lttng_agent_events(
3588 agt, events,
3589 total_size);
3590 break;
3591 }
3592 }
3593 rcu_read_unlock();
3594 }
3595 break;
3596 default:
3597 ret = LTTNG_ERR_UND;
3598 goto error;
3599 }
3600
3601 return nb_event;
3602
3603 error:
3604 /* Return negative value to differentiate return code */
3605 return -ret;
3606 }
3607
3608 /*
3609 * Using the session list, filled a lttng_session array to send back to the
3610 * client for session listing.
3611 *
3612 * The session list lock MUST be acquired before calling this function. Use
3613 * session_lock_list() and session_unlock_list().
3614 */
3615 void cmd_list_lttng_sessions(struct lttng_session *sessions,
3616 size_t session_count, uid_t uid, gid_t gid)
3617 {
3618 int ret;
3619 unsigned int i = 0;
3620 struct ltt_session *session;
3621 struct ltt_session_list *list = session_get_list();
3622 struct lttng_session_extended *extended =
3623 (typeof(extended)) (&sessions[session_count]);
3624
3625 DBG("Getting all available session for UID %d GID %d",
3626 uid, gid);
3627 /*
3628 * Iterate over session list and append data after the control struct in
3629 * the buffer.
3630 */
3631 cds_list_for_each_entry(session, &list->head, list) {
3632 if (!session_get(session)) {
3633 continue;
3634 }
3635 /*
3636 * Only list the sessions the user can control.
3637 */
3638 if (!session_access_ok(session, uid, gid) ||
3639 session->destroyed) {
3640 session_put(session);
3641 continue;
3642 }
3643
3644 struct ltt_kernel_session *ksess = session->kernel_session;
3645 struct ltt_ust_session *usess = session->ust_session;
3646
3647 if (session->consumer->type == CONSUMER_DST_NET ||
3648 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3649 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3650 ret = build_network_session_path(sessions[i].path,
3651 sizeof(sessions[i].path), session);
3652 } else {
3653 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3654 session->consumer->dst.session_root_path);
3655 }
3656 if (ret < 0) {
3657 PERROR("snprintf session path");
3658 session_put(session);
3659 continue;
3660 }
3661
3662 strncpy(sessions[i].name, session->name, NAME_MAX);
3663 sessions[i].name[NAME_MAX - 1] = '\0';
3664 sessions[i].enabled = session->active;
3665 sessions[i].snapshot_mode = session->snapshot_mode;
3666 sessions[i].live_timer_interval = session->live_timer;
3667 extended[i].creation_time.value = (uint64_t) session->creation_time;
3668 extended[i].creation_time.is_set = 1;
3669 i++;
3670 session_put(session);
3671 }
3672 }
3673
3674 /*
3675 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3676 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3677 */
3678 int cmd_data_pending(struct ltt_session *session)
3679 {
3680 int ret;
3681 struct ltt_kernel_session *ksess = session->kernel_session;
3682 struct ltt_ust_session *usess = session->ust_session;
3683
3684 assert(session);
3685
3686 DBG("Data pending for session %s", session->name);
3687
3688 /* Session MUST be stopped to ask for data availability. */
3689 if (session->active) {
3690 ret = LTTNG_ERR_SESSION_STARTED;
3691 goto error;
3692 } else {
3693 /*
3694 * If stopped, just make sure we've started before else the above call
3695 * will always send that there is data pending.
3696 *
3697 * The consumer assumes that when the data pending command is received,
3698 * the trace has been started before or else no output data is written
3699 * by the streams which is a condition for data pending. So, this is
3700 * *VERY* important that we don't ask the consumer before a start
3701 * trace.
3702 */
3703 if (!session->has_been_started) {
3704 ret = 0;
3705 goto error;
3706 }
3707 }
3708
3709 /* A rotation is still pending, we have to wait. */
3710 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3711 DBG("Rotate still pending for session %s", session->name);
3712 ret = 1;
3713 goto error;
3714 }
3715
3716 if (ksess && ksess->consumer) {
3717 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3718 if (ret == 1) {
3719 /* Data is still being extracted for the kernel. */
3720 goto error;
3721 }
3722 }
3723
3724 if (usess && usess->consumer) {
3725 ret = consumer_is_data_pending(usess->id, usess->consumer);
3726 if (ret == 1) {
3727 /* Data is still being extracted for the kernel. */
3728 goto error;
3729 }
3730 }
3731
3732 /* Data is ready to be read by a viewer */
3733 ret = 0;
3734
3735 error:
3736 return ret;
3737 }
3738
3739 /*
3740 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3741 *
3742 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3743 */
3744 int cmd_snapshot_add_output(struct ltt_session *session,
3745 const struct lttng_snapshot_output *output, uint32_t *id)
3746 {
3747 int ret;
3748 struct snapshot_output *new_output;
3749
3750 assert(session);
3751 assert(output);
3752
3753 DBG("Cmd snapshot add output for session %s", session->name);
3754
3755 /*
3756 * Can't create an output if the session is not set in no-output mode.
3757 */
3758 if (session->output_traces) {
3759 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3760 goto error;
3761 }
3762
3763 if (session->has_non_mmap_channel) {