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Fix: no-output sessions do not enforce snapshot constraints
[lttng-tools.git] / src / bin / lttng-sessiond / cmd.c
1 /*
2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <inttypes.h>
22 #include <urcu/list.h>
23 #include <urcu/uatomic.h>
24 #include <sys/stat.h>
25
26 #include <common/defaults.h>
27 #include <common/common.h>
28 #include <common/sessiond-comm/sessiond-comm.h>
29 #include <common/relayd/relayd.h>
30 #include <common/utils.h>
31 #include <common/compat/string.h>
32 #include <common/kernel-ctl/kernel-ctl.h>
33 #include <common/dynamic-buffer.h>
34 #include <common/buffer-view.h>
35 #include <lttng/trigger/trigger-internal.h>
36 #include <lttng/condition/condition.h>
37 #include <lttng/action/action.h>
38 #include <lttng/channel.h>
39 #include <lttng/channel-internal.h>
40 #include <lttng/rotate-internal.h>
41 #include <lttng/location-internal.h>
42 #include <lttng/userspace-probe-internal.h>
43 #include <common/string-utils/string-utils.h>
44
45 #include "channel.h"
46 #include "consumer.h"
47 #include "event.h"
48 #include "health-sessiond.h"
49 #include "kernel.h"
50 #include "kernel-consumer.h"
51 #include "lttng-sessiond.h"
52 #include "utils.h"
53 #include "lttng-syscall.h"
54 #include "agent.h"
55 #include "buffer-registry.h"
56 #include "notification-thread.h"
57 #include "notification-thread-commands.h"
58 #include "rotate.h"
59 #include "rotation-thread.h"
60 #include "timer.h"
61 #include "agent-thread.h"
62
63 #include "cmd.h"
64
65 /* Sleep for 100ms between each check for the shm path's deletion. */
66 #define SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US 100000
67
68 static enum lttng_error_code wait_on_path(void *path);
69
70 /*
71 * Command completion handler that is used by the destroy command
72 * when a session that has a non-default shm_path is being destroyed.
73 *
74 * See comment in cmd_destroy_session() for the rationale.
75 */
76 static struct destroy_completion_handler {
77 struct cmd_completion_handler handler;
78 char shm_path[member_sizeof(struct ltt_session, shm_path)];
79 } destroy_completion_handler = {
80 .handler = {
81 .run = wait_on_path,
82 .data = destroy_completion_handler.shm_path
83 },
84 .shm_path = { 0 },
85 };
86
87 static struct cmd_completion_handler *current_completion_handler;
88
89 /*
90 * Used to keep a unique index for each relayd socket created where this value
91 * is associated with streams on the consumer so it can match the right relayd
92 * to send to. It must be accessed with the relayd_net_seq_idx_lock
93 * held.
94 */
95 static pthread_mutex_t relayd_net_seq_idx_lock = PTHREAD_MUTEX_INITIALIZER;
96 static uint64_t relayd_net_seq_idx;
97
98 static int validate_ust_event_name(const char *);
99 static int cmd_enable_event_internal(struct ltt_session *session,
100 struct lttng_domain *domain,
101 char *channel_name, struct lttng_event *event,
102 char *filter_expression,
103 struct lttng_filter_bytecode *filter,
104 struct lttng_event_exclusion *exclusion,
105 int wpipe);
106
107 /*
108 * Create a session path used by list_lttng_sessions for the case that the
109 * session consumer is on the network.
110 */
111 static int build_network_session_path(char *dst, size_t size,
112 struct ltt_session *session)
113 {
114 int ret, kdata_port, udata_port;
115 struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
116 char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
117
118 assert(session);
119 assert(dst);
120
121 memset(tmp_urls, 0, sizeof(tmp_urls));
122 memset(tmp_uurl, 0, sizeof(tmp_uurl));
123
124 kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
125
126 if (session->kernel_session && session->kernel_session->consumer) {
127 kuri = &session->kernel_session->consumer->dst.net.control;
128 kdata_port = session->kernel_session->consumer->dst.net.data.port;
129 }
130
131 if (session->ust_session && session->ust_session->consumer) {
132 uuri = &session->ust_session->consumer->dst.net.control;
133 udata_port = session->ust_session->consumer->dst.net.data.port;
134 }
135
136 if (uuri == NULL && kuri == NULL) {
137 uri = &session->consumer->dst.net.control;
138 kdata_port = session->consumer->dst.net.data.port;
139 } else if (kuri && uuri) {
140 ret = uri_compare(kuri, uuri);
141 if (ret) {
142 /* Not Equal */
143 uri = kuri;
144 /* Build uuri URL string */
145 ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
146 if (ret < 0) {
147 goto error;
148 }
149 } else {
150 uri = kuri;
151 }
152 } else if (kuri && uuri == NULL) {
153 uri = kuri;
154 } else if (uuri && kuri == NULL) {
155 uri = uuri;
156 }
157
158 ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
159 if (ret < 0) {
160 goto error;
161 }
162
163 /*
164 * Do we have a UST url set. If yes, this means we have both kernel and UST
165 * to print.
166 */
167 if (*tmp_uurl != '\0') {
168 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
169 tmp_urls, kdata_port, tmp_uurl, udata_port);
170 } else {
171 int dport;
172 if (kuri || (!kuri && !uuri)) {
173 dport = kdata_port;
174 } else {
175 /* No kernel URI, use the UST port. */
176 dport = udata_port;
177 }
178 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
179 }
180
181 error:
182 return ret;
183 }
184
185 /*
186 * Get run-time attributes if the session has been started (discarded events,
187 * lost packets).
188 */
189 static int get_kernel_runtime_stats(struct ltt_session *session,
190 struct ltt_kernel_channel *kchan, uint64_t *discarded_events,
191 uint64_t *lost_packets)
192 {
193 int ret;
194
195 if (!session->has_been_started) {
196 ret = 0;
197 *discarded_events = 0;
198 *lost_packets = 0;
199 goto end;
200 }
201
202 ret = consumer_get_discarded_events(session->id, kchan->key,
203 session->kernel_session->consumer,
204 discarded_events);
205 if (ret < 0) {
206 goto end;
207 }
208
209 ret = consumer_get_lost_packets(session->id, kchan->key,
210 session->kernel_session->consumer,
211 lost_packets);
212 if (ret < 0) {
213 goto end;
214 }
215
216 end:
217 return ret;
218 }
219
220 /*
221 * Get run-time attributes if the session has been started (discarded events,
222 * lost packets).
223 */
224 static int get_ust_runtime_stats(struct ltt_session *session,
225 struct ltt_ust_channel *uchan, uint64_t *discarded_events,
226 uint64_t *lost_packets)
227 {
228 int ret;
229 struct ltt_ust_session *usess;
230
231 if (!discarded_events || !lost_packets) {
232 ret = -1;
233 goto end;
234 }
235
236 usess = session->ust_session;
237 assert(discarded_events);
238 assert(lost_packets);
239
240 if (!usess || !session->has_been_started) {
241 *discarded_events = 0;
242 *lost_packets = 0;
243 ret = 0;
244 goto end;
245 }
246
247 if (usess->buffer_type == LTTNG_BUFFER_PER_UID) {
248 ret = ust_app_uid_get_channel_runtime_stats(usess->id,
249 &usess->buffer_reg_uid_list,
250 usess->consumer, uchan->id,
251 uchan->attr.overwrite,
252 discarded_events,
253 lost_packets);
254 } else if (usess->buffer_type == LTTNG_BUFFER_PER_PID) {
255 ret = ust_app_pid_get_channel_runtime_stats(usess,
256 uchan, usess->consumer,
257 uchan->attr.overwrite,
258 discarded_events,
259 lost_packets);
260 if (ret < 0) {
261 goto end;
262 }
263 *discarded_events += uchan->per_pid_closed_app_discarded;
264 *lost_packets += uchan->per_pid_closed_app_lost;
265 } else {
266 ERR("Unsupported buffer type");
267 assert(0);
268 ret = -1;
269 goto end;
270 }
271
272 end:
273 return ret;
274 }
275
276 /*
277 * Fill lttng_channel array of all channels.
278 */
279 static ssize_t list_lttng_channels(enum lttng_domain_type domain,
280 struct ltt_session *session, struct lttng_channel *channels,
281 struct lttng_channel_extended *chan_exts)
282 {
283 int i = 0, ret = 0;
284 struct ltt_kernel_channel *kchan;
285
286 DBG("Listing channels for session %s", session->name);
287
288 switch (domain) {
289 case LTTNG_DOMAIN_KERNEL:
290 /* Kernel channels */
291 if (session->kernel_session != NULL) {
292 cds_list_for_each_entry(kchan,
293 &session->kernel_session->channel_list.head, list) {
294 uint64_t discarded_events, lost_packets;
295 struct lttng_channel_extended *extended;
296
297 extended = (struct lttng_channel_extended *)
298 kchan->channel->attr.extended.ptr;
299
300 ret = get_kernel_runtime_stats(session, kchan,
301 &discarded_events, &lost_packets);
302 if (ret < 0) {
303 goto end;
304 }
305 /* Copy lttng_channel struct to array */
306 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
307 channels[i].enabled = kchan->enabled;
308 chan_exts[i].discarded_events =
309 discarded_events;
310 chan_exts[i].lost_packets = lost_packets;
311 chan_exts[i].monitor_timer_interval =
312 extended->monitor_timer_interval;
313 chan_exts[i].blocking_timeout = 0;
314 i++;
315 }
316 }
317 break;
318 case LTTNG_DOMAIN_UST:
319 {
320 struct lttng_ht_iter iter;
321 struct ltt_ust_channel *uchan;
322
323 rcu_read_lock();
324 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
325 &iter.iter, uchan, node.node) {
326 uint64_t discarded_events = 0, lost_packets = 0;
327
328 if (lttng_strncpy(channels[i].name, uchan->name,
329 LTTNG_SYMBOL_NAME_LEN)) {
330 break;
331 }
332 channels[i].attr.overwrite = uchan->attr.overwrite;
333 channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
334 channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
335 channels[i].attr.switch_timer_interval =
336 uchan->attr.switch_timer_interval;
337 channels[i].attr.read_timer_interval =
338 uchan->attr.read_timer_interval;
339 channels[i].enabled = uchan->enabled;
340 channels[i].attr.tracefile_size = uchan->tracefile_size;
341 channels[i].attr.tracefile_count = uchan->tracefile_count;
342
343 /*
344 * Map enum lttng_ust_output to enum lttng_event_output.
345 */
346 switch (uchan->attr.output) {
347 case LTTNG_UST_MMAP:
348 channels[i].attr.output = LTTNG_EVENT_MMAP;
349 break;
350 default:
351 /*
352 * LTTNG_UST_MMAP is the only supported UST
353 * output mode.
354 */
355 assert(0);
356 break;
357 }
358
359 chan_exts[i].monitor_timer_interval =
360 uchan->monitor_timer_interval;
361 chan_exts[i].blocking_timeout =
362 uchan->attr.u.s.blocking_timeout;
363
364 ret = get_ust_runtime_stats(session, uchan,
365 &discarded_events, &lost_packets);
366 if (ret < 0) {
367 break;
368 }
369 chan_exts[i].discarded_events = discarded_events;
370 chan_exts[i].lost_packets = lost_packets;
371 i++;
372 }
373 rcu_read_unlock();
374 break;
375 }
376 default:
377 break;
378 }
379
380 end:
381 if (ret < 0) {
382 return -LTTNG_ERR_FATAL;
383 } else {
384 return LTTNG_OK;
385 }
386 }
387
388 static int increment_extended_len(const char *filter_expression,
389 struct lttng_event_exclusion *exclusion,
390 const struct lttng_userspace_probe_location *probe_location,
391 size_t *extended_len)
392 {
393 int ret = 0;
394
395 *extended_len += sizeof(struct lttcomm_event_extended_header);
396
397 if (filter_expression) {
398 *extended_len += strlen(filter_expression) + 1;
399 }
400
401 if (exclusion) {
402 *extended_len += exclusion->count * LTTNG_SYMBOL_NAME_LEN;
403 }
404
405 if (probe_location) {
406 ret = lttng_userspace_probe_location_serialize(probe_location,
407 NULL, NULL);
408 if (ret < 0) {
409 goto end;
410 }
411 *extended_len += ret;
412 }
413 ret = 0;
414 end:
415 return ret;
416 }
417
418 static int append_extended_info(const char *filter_expression,
419 struct lttng_event_exclusion *exclusion,
420 struct lttng_userspace_probe_location *probe_location,
421 void **extended_at)
422 {
423 int ret = 0;
424 size_t filter_len = 0;
425 size_t nb_exclusions = 0;
426 size_t userspace_probe_location_len = 0;
427 struct lttng_dynamic_buffer location_buffer;
428 struct lttcomm_event_extended_header extended_header;
429
430 if (filter_expression) {
431 filter_len = strlen(filter_expression) + 1;
432 }
433
434 if (exclusion) {
435 nb_exclusions = exclusion->count;
436 }
437
438 if (probe_location) {
439 lttng_dynamic_buffer_init(&location_buffer);
440 ret = lttng_userspace_probe_location_serialize(probe_location,
441 &location_buffer, NULL);
442 if (ret < 0) {
443 ret = -1;
444 goto end;
445 }
446 userspace_probe_location_len = location_buffer.size;
447 }
448
449 /* Set header fields */
450 extended_header.filter_len = filter_len;
451 extended_header.nb_exclusions = nb_exclusions;
452 extended_header.userspace_probe_location_len = userspace_probe_location_len;
453
454 /* Copy header */
455 memcpy(*extended_at, &extended_header, sizeof(extended_header));
456 *extended_at += sizeof(extended_header);
457
458 /* Copy filter string */
459 if (filter_expression) {
460 memcpy(*extended_at, filter_expression, filter_len);
461 *extended_at += filter_len;
462 }
463
464 /* Copy exclusion names */
465 if (exclusion) {
466 size_t len = nb_exclusions * LTTNG_SYMBOL_NAME_LEN;
467
468 memcpy(*extended_at, &exclusion->names, len);
469 *extended_at += len;
470 }
471
472 if (probe_location) {
473 memcpy(*extended_at, location_buffer.data, location_buffer.size);
474 *extended_at += location_buffer.size;
475 lttng_dynamic_buffer_reset(&location_buffer);
476 }
477 ret = 0;
478 end:
479 return ret;
480 }
481
482 /*
483 * Create a list of agent domain events.
484 *
485 * Return number of events in list on success or else a negative value.
486 */
487 static int list_lttng_agent_events(struct agent *agt,
488 struct lttng_event **events, size_t *total_size)
489 {
490 int i = 0, ret = 0;
491 unsigned int nb_event = 0;
492 struct agent_event *event;
493 struct lttng_event *tmp_events = NULL;
494 struct lttng_ht_iter iter;
495 size_t extended_len = 0;
496 void *extended_at;
497
498 assert(agt);
499 assert(events);
500
501 DBG3("Listing agent events");
502
503 rcu_read_lock();
504 nb_event = lttng_ht_get_count(agt->events);
505 rcu_read_unlock();
506 if (nb_event == 0) {
507 ret = nb_event;
508 *total_size = 0;
509 goto error;
510 }
511
512 /* Compute required extended infos size */
513 extended_len = nb_event * sizeof(struct lttcomm_event_extended_header);
514
515 /*
516 * This is only valid because the commands which add events are
517 * processed in the same thread as the listing.
518 */
519 rcu_read_lock();
520 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
521 ret = increment_extended_len(event->filter_expression, NULL, NULL,
522 &extended_len);
523 if (ret) {
524 DBG("Error computing the length of extended info message");
525 ret = -LTTNG_ERR_FATAL;
526 goto error;
527 }
528 }
529 rcu_read_unlock();
530
531 *total_size = nb_event * sizeof(*tmp_events) + extended_len;
532 tmp_events = zmalloc(*total_size);
533 if (!tmp_events) {
534 PERROR("zmalloc agent events session");
535 ret = -LTTNG_ERR_FATAL;
536 goto error;
537 }
538
539 extended_at = ((uint8_t *) tmp_events) +
540 nb_event * sizeof(struct lttng_event);
541
542 rcu_read_lock();
543 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
544 strncpy(tmp_events[i].name, event->name, sizeof(tmp_events[i].name));
545 tmp_events[i].name[sizeof(tmp_events[i].name) - 1] = '\0';
546 tmp_events[i].enabled = event->enabled;
547 tmp_events[i].loglevel = event->loglevel_value;
548 tmp_events[i].loglevel_type = event->loglevel_type;
549 i++;
550
551 /* Append extended info */
552 ret = append_extended_info(event->filter_expression, NULL, NULL,
553 &extended_at);
554 if (ret) {
555 DBG("Error appending extended info message");
556 ret = -LTTNG_ERR_FATAL;
557 goto error;
558 }
559 }
560
561 *events = tmp_events;
562 ret = nb_event;
563 assert(nb_event == i);
564
565 end:
566 rcu_read_unlock();
567 return ret;
568 error:
569 free(tmp_events);
570 goto end;
571 }
572
573 /*
574 * Create a list of ust global domain events.
575 */
576 static int list_lttng_ust_global_events(char *channel_name,
577 struct ltt_ust_domain_global *ust_global,
578 struct lttng_event **events, size_t *total_size)
579 {
580 int i = 0, ret = 0;
581 unsigned int nb_event = 0;
582 struct lttng_ht_iter iter;
583 struct lttng_ht_node_str *node;
584 struct ltt_ust_channel *uchan;
585 struct ltt_ust_event *uevent;
586 struct lttng_event *tmp;
587 size_t extended_len = 0;
588 void *extended_at;
589
590 DBG("Listing UST global events for channel %s", channel_name);
591
592 rcu_read_lock();
593
594 lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
595 node = lttng_ht_iter_get_node_str(&iter);
596 if (node == NULL) {
597 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
598 goto end;
599 }
600
601 uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
602
603 nb_event = lttng_ht_get_count(uchan->events);
604 if (nb_event == 0) {
605 ret = nb_event;
606 *total_size = 0;
607 goto end;
608 }
609
610 DBG3("Listing UST global %d events", nb_event);
611
612 /* Compute required extended infos size */
613 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
614 if (uevent->internal) {
615 nb_event--;
616 continue;
617 }
618
619 ret = increment_extended_len(uevent->filter_expression,
620 uevent->exclusion, NULL, &extended_len);
621 if (ret) {
622 DBG("Error computing the length of extended info message");
623 ret = -LTTNG_ERR_FATAL;
624 goto end;
625 }
626 }
627 if (nb_event == 0) {
628 /* All events are internal, skip. */
629 ret = 0;
630 *total_size = 0;
631 goto end;
632 }
633
634 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
635 tmp = zmalloc(*total_size);
636 if (tmp == NULL) {
637 ret = -LTTNG_ERR_FATAL;
638 goto end;
639 }
640
641 extended_at = ((uint8_t *) tmp) + nb_event * sizeof(struct lttng_event);
642
643 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
644 if (uevent->internal) {
645 /* This event should remain hidden from clients */
646 continue;
647 }
648 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
649 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
650 tmp[i].enabled = uevent->enabled;
651
652 switch (uevent->attr.instrumentation) {
653 case LTTNG_UST_TRACEPOINT:
654 tmp[i].type = LTTNG_EVENT_TRACEPOINT;
655 break;
656 case LTTNG_UST_PROBE:
657 tmp[i].type = LTTNG_EVENT_PROBE;
658 break;
659 case LTTNG_UST_FUNCTION:
660 tmp[i].type = LTTNG_EVENT_FUNCTION;
661 break;
662 }
663
664 tmp[i].loglevel = uevent->attr.loglevel;
665 switch (uevent->attr.loglevel_type) {
666 case LTTNG_UST_LOGLEVEL_ALL:
667 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
668 break;
669 case LTTNG_UST_LOGLEVEL_RANGE:
670 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
671 break;
672 case LTTNG_UST_LOGLEVEL_SINGLE:
673 tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
674 break;
675 }
676 if (uevent->filter) {
677 tmp[i].filter = 1;
678 }
679 if (uevent->exclusion) {
680 tmp[i].exclusion = 1;
681 }
682 i++;
683
684 /* Append extended info */
685 ret = append_extended_info(uevent->filter_expression,
686 uevent->exclusion, NULL, &extended_at);
687 if (ret) {
688 DBG("Error appending extended info message");
689 ret = -LTTNG_ERR_FATAL;
690 goto end;
691 }
692 }
693
694 ret = nb_event;
695 *events = tmp;
696 end:
697 rcu_read_unlock();
698 return ret;
699 }
700
701 /*
702 * Fill lttng_event array of all kernel events in the channel.
703 */
704 static int list_lttng_kernel_events(char *channel_name,
705 struct ltt_kernel_session *kernel_session,
706 struct lttng_event **events, size_t *total_size)
707 {
708 int i = 0, ret;
709 unsigned int nb_event;
710 struct ltt_kernel_event *event;
711 struct ltt_kernel_channel *kchan;
712 size_t extended_len = 0;
713 void *extended_at;
714
715 kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
716 if (kchan == NULL) {
717 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
718 goto error;
719 }
720
721 nb_event = kchan->event_count;
722
723 DBG("Listing events for channel %s", kchan->channel->name);
724
725 if (nb_event == 0) {
726 *total_size = 0;
727 *events = NULL;
728 goto end;
729 }
730
731 /* Compute required extended infos size */
732 cds_list_for_each_entry(event, &kchan->events_list.head, list) {
733 ret = increment_extended_len(event->filter_expression, NULL,
734 event->userspace_probe_location,
735 &extended_len);
736 if (ret) {
737 DBG("Error computing the length of extended info message");
738 ret = -LTTNG_ERR_FATAL;
739 goto error;
740 }
741 }
742
743 *total_size = nb_event * sizeof(struct lttng_event) + extended_len;
744 *events = zmalloc(*total_size);
745 if (*events == NULL) {
746 ret = -LTTNG_ERR_FATAL;
747 goto error;
748 }
749
750 extended_at = ((void *) *events) +
751 nb_event * sizeof(struct lttng_event);
752
753 /* Kernel channels */
754 cds_list_for_each_entry(event, &kchan->events_list.head , list) {
755 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
756 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
757 (*events)[i].enabled = event->enabled;
758 (*events)[i].filter =
759 (unsigned char) !!event->filter_expression;
760
761 switch (event->event->instrumentation) {
762 case LTTNG_KERNEL_TRACEPOINT:
763 (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
764 break;
765 case LTTNG_KERNEL_KRETPROBE:
766 (*events)[i].type = LTTNG_EVENT_FUNCTION;
767 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
768 sizeof(struct lttng_kernel_kprobe));
769 break;
770 case LTTNG_KERNEL_KPROBE:
771 (*events)[i].type = LTTNG_EVENT_PROBE;
772 memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
773 sizeof(struct lttng_kernel_kprobe));
774 break;
775 case LTTNG_KERNEL_UPROBE:
776 (*events)[i].type = LTTNG_EVENT_USERSPACE_PROBE;
777 break;
778 case LTTNG_KERNEL_FUNCTION:
779 (*events)[i].type = LTTNG_EVENT_FUNCTION;
780 memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
781 sizeof(struct lttng_kernel_function));
782 break;
783 case LTTNG_KERNEL_NOOP:
784 (*events)[i].type = LTTNG_EVENT_NOOP;
785 break;
786 case LTTNG_KERNEL_SYSCALL:
787 (*events)[i].type = LTTNG_EVENT_SYSCALL;
788 break;
789 case LTTNG_KERNEL_ALL:
790 /* fall-through. */
791 default:
792 assert(0);
793 break;
794 }
795 i++;
796
797 /* Append extended info */
798 ret = append_extended_info(event->filter_expression, NULL,
799 event->userspace_probe_location, &extended_at);
800 if (ret) {
801 DBG("Error appending extended info message");
802 ret = -LTTNG_ERR_FATAL;
803 goto error;
804 }
805 }
806
807 end:
808 return nb_event;
809
810 error:
811 /* Negate the error code to differentiate the size from an error */
812 return -ret;
813 }
814
815 /*
816 * Add URI so the consumer output object. Set the correct path depending on the
817 * domain adding the default trace directory.
818 */
819 static int add_uri_to_consumer(struct consumer_output *consumer,
820 struct lttng_uri *uri, enum lttng_domain_type domain,
821 const char *session_name)
822 {
823 int ret = LTTNG_OK;
824 const char *default_trace_dir;
825
826 assert(uri);
827
828 if (consumer == NULL) {
829 DBG("No consumer detected. Don't add URI. Stopping.");
830 ret = LTTNG_ERR_NO_CONSUMER;
831 goto error;
832 }
833
834 switch (domain) {
835 case LTTNG_DOMAIN_KERNEL:
836 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
837 break;
838 case LTTNG_DOMAIN_UST:
839 default_trace_dir = DEFAULT_UST_TRACE_DIR;
840 break;
841 default:
842 /*
843 * This case is possible is we try to add the URI to the global tracing
844 * session consumer object which in this case there is no subdir.
845 */
846 default_trace_dir = "";
847 }
848
849 switch (uri->dtype) {
850 case LTTNG_DST_IPV4:
851 case LTTNG_DST_IPV6:
852 DBG2("Setting network URI to consumer");
853
854 if (consumer->type == CONSUMER_DST_NET) {
855 if ((uri->stype == LTTNG_STREAM_CONTROL &&
856 consumer->dst.net.control_isset) ||
857 (uri->stype == LTTNG_STREAM_DATA &&
858 consumer->dst.net.data_isset)) {
859 ret = LTTNG_ERR_URL_EXIST;
860 goto error;
861 }
862 } else {
863 memset(&consumer->dst.net, 0, sizeof(consumer->dst.net));
864 }
865
866 consumer->type = CONSUMER_DST_NET;
867
868 /* Set URI into consumer output object */
869 ret = consumer_set_network_uri(consumer, uri);
870 if (ret < 0) {
871 ret = -ret;
872 goto error;
873 } else if (ret == 1) {
874 /*
875 * URI was the same in the consumer so we do not append the subdir
876 * again so to not duplicate output dir.
877 */
878 ret = LTTNG_OK;
879 goto error;
880 }
881
882 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
883 ret = consumer_set_subdir(consumer, session_name);
884 if (ret < 0) {
885 ret = LTTNG_ERR_FATAL;
886 goto error;
887 }
888 }
889
890 if (uri->stype == LTTNG_STREAM_CONTROL) {
891 /* On a new subdir, reappend the default trace dir. */
892 strncat(consumer->subdir, default_trace_dir,
893 sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
894 DBG3("Append domain trace name to subdir %s", consumer->subdir);
895 }
896
897 break;
898 case LTTNG_DST_PATH:
899 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
900 memset(consumer->dst.session_root_path, 0,
901 sizeof(consumer->dst.session_root_path));
902 /* Explicit length checks for strcpy and strcat. */
903 if (strlen(uri->dst.path) + strlen(default_trace_dir)
904 >= sizeof(consumer->dst.session_root_path)) {
905 ret = LTTNG_ERR_FATAL;
906 goto error;
907 }
908 strcpy(consumer->dst.session_root_path, uri->dst.path);
909 /* Append default trace dir */
910 strcat(consumer->dst.session_root_path, default_trace_dir);
911 /* Flag consumer as local. */
912 consumer->type = CONSUMER_DST_LOCAL;
913 break;
914 }
915
916 ret = LTTNG_OK;
917
918 error:
919 return ret;
920 }
921
922 /*
923 * Init tracing by creating trace directory and sending fds kernel consumer.
924 */
925 static int init_kernel_tracing(struct ltt_kernel_session *session)
926 {
927 int ret = 0;
928 struct lttng_ht_iter iter;
929 struct consumer_socket *socket;
930
931 assert(session);
932
933 rcu_read_lock();
934
935 if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
936 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
937 socket, node.node) {
938 pthread_mutex_lock(socket->lock);
939 ret = kernel_consumer_send_session(socket, session);
940 pthread_mutex_unlock(socket->lock);
941 if (ret < 0) {
942 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
943 goto error;
944 }
945 }
946 }
947
948 error:
949 rcu_read_unlock();
950 return ret;
951 }
952
953 /*
954 * Create a socket to the relayd using the URI.
955 *
956 * On success, the relayd_sock pointer is set to the created socket.
957 * Else, it remains untouched and an LTTng error code is returned.
958 */
959 static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
960 struct lttcomm_relayd_sock **relayd_sock,
961 struct consumer_output *consumer)
962 {
963 int ret;
964 enum lttng_error_code status = LTTNG_OK;
965 struct lttcomm_relayd_sock *rsock;
966
967 rsock = lttcomm_alloc_relayd_sock(uri, RELAYD_VERSION_COMM_MAJOR,
968 RELAYD_VERSION_COMM_MINOR);
969 if (!rsock) {
970 status = LTTNG_ERR_FATAL;
971 goto error;
972 }
973
974 /*
975 * Connect to relayd so we can proceed with a session creation. This call
976 * can possibly block for an arbitrary amount of time to set the health
977 * state to be in poll execution.
978 */
979 health_poll_entry();
980 ret = relayd_connect(rsock);
981 health_poll_exit();
982 if (ret < 0) {
983 ERR("Unable to reach lttng-relayd");
984 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
985 goto free_sock;
986 }
987
988 /* Create socket for control stream. */
989 if (uri->stype == LTTNG_STREAM_CONTROL) {
990 DBG3("Creating relayd stream socket from URI");
991
992 /* Check relayd version */
993 ret = relayd_version_check(rsock);
994 if (ret == LTTNG_ERR_RELAYD_VERSION_FAIL) {
995 status = LTTNG_ERR_RELAYD_VERSION_FAIL;
996 goto close_sock;
997 } else if (ret < 0) {
998 ERR("Unable to reach lttng-relayd");
999 status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
1000 goto close_sock;
1001 }
1002 consumer->relay_major_version = rsock->major;
1003 consumer->relay_minor_version = rsock->minor;
1004 } else if (uri->stype == LTTNG_STREAM_DATA) {
1005 DBG3("Creating relayd data socket from URI");
1006 } else {
1007 /* Command is not valid */
1008 ERR("Relayd invalid stream type: %d", uri->stype);
1009 status = LTTNG_ERR_INVALID;
1010 goto close_sock;
1011 }
1012
1013 *relayd_sock = rsock;
1014
1015 return status;
1016
1017 close_sock:
1018 /* The returned value is not useful since we are on an error path. */
1019 (void) relayd_close(rsock);
1020 free_sock:
1021 free(rsock);
1022 error:
1023 return status;
1024 }
1025
1026 /*
1027 * Connect to the relayd using URI and send the socket to the right consumer.
1028 *
1029 * The consumer socket lock must be held by the caller.
1030 *
1031 * Returns LTTNG_OK on success or an LTTng error code on failure.
1032 */
1033 static enum lttng_error_code send_consumer_relayd_socket(
1034 unsigned int session_id,
1035 struct lttng_uri *relayd_uri,
1036 struct consumer_output *consumer,
1037 struct consumer_socket *consumer_sock,
1038 char *session_name, char *hostname, int session_live_timer)
1039 {
1040 int ret;
1041 struct lttcomm_relayd_sock *rsock = NULL;
1042 enum lttng_error_code status;
1043
1044 /* Connect to relayd and make version check if uri is the control. */
1045 status = create_connect_relayd(relayd_uri, &rsock, consumer);
1046 if (status != LTTNG_OK) {
1047 goto relayd_comm_error;
1048 }
1049 assert(rsock);
1050
1051 /* Set the network sequence index if not set. */
1052 if (consumer->net_seq_index == (uint64_t) -1ULL) {
1053 pthread_mutex_lock(&relayd_net_seq_idx_lock);
1054 /*
1055 * Increment net_seq_idx because we are about to transfer the
1056 * new relayd socket to the consumer.
1057 * Assign unique key so the consumer can match streams.
1058 */
1059 consumer->net_seq_index = ++relayd_net_seq_idx;
1060 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
1061 }
1062
1063 /* Send relayd socket to consumer. */
1064 ret = consumer_send_relayd_socket(consumer_sock, rsock, consumer,
1065 relayd_uri->stype, session_id,
1066 session_name, hostname, session_live_timer);
1067 if (ret < 0) {
1068 status = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
1069 goto close_sock;
1070 }
1071
1072 /* Flag that the corresponding socket was sent. */
1073 if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
1074 consumer_sock->control_sock_sent = 1;
1075 } else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
1076 consumer_sock->data_sock_sent = 1;
1077 }
1078
1079 /*
1080 * Close socket which was dup on the consumer side. The session daemon does
1081 * NOT keep track of the relayd socket(s) once transfer to the consumer.
1082 */
1083
1084 close_sock:
1085 if (status != LTTNG_OK) {
1086 /*
1087 * The consumer output for this session should not be used anymore
1088 * since the relayd connection failed thus making any tracing or/and
1089 * streaming not usable.
1090 */
1091 consumer->enabled = 0;
1092 }
1093 (void) relayd_close(rsock);
1094 free(rsock);
1095
1096 relayd_comm_error:
1097 return status;
1098 }
1099
1100 /*
1101 * Send both relayd sockets to a specific consumer and domain. This is a
1102 * helper function to facilitate sending the information to the consumer for a
1103 * session.
1104 *
1105 * The consumer socket lock must be held by the caller.
1106 *
1107 * Returns LTTNG_OK, or an LTTng error code on failure.
1108 */
1109 static enum lttng_error_code send_consumer_relayd_sockets(
1110 enum lttng_domain_type domain,
1111 unsigned int session_id, struct consumer_output *consumer,
1112 struct consumer_socket *sock, char *session_name,
1113 char *hostname, int session_live_timer)
1114 {
1115 enum lttng_error_code status = LTTNG_OK;
1116
1117 assert(consumer);
1118 assert(sock);
1119
1120 /* Sending control relayd socket. */
1121 if (!sock->control_sock_sent) {
1122 status = send_consumer_relayd_socket(session_id,
1123 &consumer->dst.net.control, consumer, sock,
1124 session_name, hostname, session_live_timer);
1125 if (status != LTTNG_OK) {
1126 goto error;
1127 }
1128 }
1129
1130 /* Sending data relayd socket. */
1131 if (!sock->data_sock_sent) {
1132 status = send_consumer_relayd_socket(session_id,
1133 &consumer->dst.net.data, consumer, sock,
1134 session_name, hostname, session_live_timer);
1135 if (status != LTTNG_OK) {
1136 goto error;
1137 }
1138 }
1139
1140 error:
1141 return status;
1142 }
1143
1144 /*
1145 * Setup relayd connections for a tracing session. First creates the socket to
1146 * the relayd and send them to the right domain consumer. Consumer type MUST be
1147 * network.
1148 */
1149 int cmd_setup_relayd(struct ltt_session *session)
1150 {
1151 int ret = LTTNG_OK;
1152 struct ltt_ust_session *usess;
1153 struct ltt_kernel_session *ksess;
1154 struct consumer_socket *socket;
1155 struct lttng_ht_iter iter;
1156
1157 assert(session);
1158
1159 usess = session->ust_session;
1160 ksess = session->kernel_session;
1161
1162 DBG("Setting relayd for session %s", session->name);
1163
1164 rcu_read_lock();
1165
1166 if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
1167 && usess->consumer->enabled) {
1168 /* For each consumer socket, send relayd sockets */
1169 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
1170 socket, node.node) {
1171 pthread_mutex_lock(socket->lock);
1172 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session->id,
1173 usess->consumer, socket,
1174 session->name, session->hostname,
1175 session->live_timer);
1176 pthread_mutex_unlock(socket->lock);
1177 if (ret != LTTNG_OK) {
1178 goto error;
1179 }
1180 /* Session is now ready for network streaming. */
1181 session->net_handle = 1;
1182 }
1183 session->consumer->relay_major_version =
1184 usess->consumer->relay_major_version;
1185 session->consumer->relay_minor_version =
1186 usess->consumer->relay_minor_version;
1187 }
1188
1189 if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
1190 && ksess->consumer->enabled) {
1191 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
1192 socket, node.node) {
1193 pthread_mutex_lock(socket->lock);
1194 ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session->id,
1195 ksess->consumer, socket,
1196 session->name, session->hostname,
1197 session->live_timer);
1198 pthread_mutex_unlock(socket->lock);
1199 if (ret != LTTNG_OK) {
1200 goto error;
1201 }
1202 /* Session is now ready for network streaming. */
1203 session->net_handle = 1;
1204 }
1205 session->consumer->relay_major_version =
1206 ksess->consumer->relay_major_version;
1207 session->consumer->relay_minor_version =
1208 ksess->consumer->relay_minor_version;
1209 }
1210
1211 error:
1212 rcu_read_unlock();
1213 return ret;
1214 }
1215
1216 /*
1217 * Start a kernel session by opening all necessary streams.
1218 */
1219 static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
1220 {
1221 int ret;
1222 struct ltt_kernel_channel *kchan;
1223
1224 /* Open kernel metadata */
1225 if (ksess->metadata == NULL && ksess->output_traces) {
1226 ret = kernel_open_metadata(ksess);
1227 if (ret < 0) {
1228 ret = LTTNG_ERR_KERN_META_FAIL;
1229 goto error;
1230 }
1231 }
1232
1233 /* Open kernel metadata stream */
1234 if (ksess->metadata && ksess->metadata_stream_fd < 0) {
1235 ret = kernel_open_metadata_stream(ksess);
1236 if (ret < 0) {
1237 ERR("Kernel create metadata stream failed");
1238 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1239 goto error;
1240 }
1241 }
1242
1243 /* For each channel */
1244 cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
1245 if (kchan->stream_count == 0) {
1246 ret = kernel_open_channel_stream(kchan);
1247 if (ret < 0) {
1248 ret = LTTNG_ERR_KERN_STREAM_FAIL;
1249 goto error;
1250 }
1251 /* Update the stream global counter */
1252 ksess->stream_count_global += ret;
1253 }
1254 }
1255
1256 /* Setup kernel consumer socket and send fds to it */
1257 ret = init_kernel_tracing(ksess);
1258 if (ret != 0) {
1259 ret = LTTNG_ERR_KERN_START_FAIL;
1260 goto error;
1261 }
1262
1263 /* This start the kernel tracing */
1264 ret = kernel_start_session(ksess);
1265 if (ret < 0) {
1266 ret = LTTNG_ERR_KERN_START_FAIL;
1267 goto error;
1268 }
1269
1270 /* Quiescent wait after starting trace */
1271 kernel_wait_quiescent(wpipe);
1272
1273 ksess->active = 1;
1274
1275 ret = LTTNG_OK;
1276
1277 error:
1278 return ret;
1279 }
1280
1281 /*
1282 * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
1283 */
1284 int cmd_disable_channel(struct ltt_session *session,
1285 enum lttng_domain_type domain, char *channel_name)
1286 {
1287 int ret;
1288 struct ltt_ust_session *usess;
1289
1290 usess = session->ust_session;
1291
1292 rcu_read_lock();
1293
1294 switch (domain) {
1295 case LTTNG_DOMAIN_KERNEL:
1296 {
1297 ret = channel_kernel_disable(session->kernel_session,
1298 channel_name);
1299 if (ret != LTTNG_OK) {
1300 goto error;
1301 }
1302
1303 kernel_wait_quiescent(kernel_tracer_fd);
1304 break;
1305 }
1306 case LTTNG_DOMAIN_UST:
1307 {
1308 struct ltt_ust_channel *uchan;
1309 struct lttng_ht *chan_ht;
1310
1311 chan_ht = usess->domain_global.channels;
1312
1313 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
1314 if (uchan == NULL) {
1315 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1316 goto error;
1317 }
1318
1319 ret = channel_ust_disable(usess, uchan);
1320 if (ret != LTTNG_OK) {
1321 goto error;
1322 }
1323 break;
1324 }
1325 default:
1326 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1327 goto error;
1328 }
1329
1330 ret = LTTNG_OK;
1331
1332 error:
1333 rcu_read_unlock();
1334 return ret;
1335 }
1336
1337 /*
1338 * Command LTTNG_TRACK_PID processed by the client thread.
1339 *
1340 * Called with session lock held.
1341 */
1342 int cmd_track_pid(struct ltt_session *session, enum lttng_domain_type domain,
1343 int pid)
1344 {
1345 int ret;
1346
1347 rcu_read_lock();
1348
1349 switch (domain) {
1350 case LTTNG_DOMAIN_KERNEL:
1351 {
1352 struct ltt_kernel_session *ksess;
1353
1354 ksess = session->kernel_session;
1355
1356 ret = kernel_track_pid(ksess, pid);
1357 if (ret != LTTNG_OK) {
1358 goto error;
1359 }
1360
1361 kernel_wait_quiescent(kernel_tracer_fd);
1362 break;
1363 }
1364 case LTTNG_DOMAIN_UST:
1365 {
1366 struct ltt_ust_session *usess;
1367
1368 usess = session->ust_session;
1369
1370 ret = trace_ust_track_pid(usess, pid);
1371 if (ret != LTTNG_OK) {
1372 goto error;
1373 }
1374 break;
1375 }
1376 default:
1377 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1378 goto error;
1379 }
1380
1381 ret = LTTNG_OK;
1382
1383 error:
1384 rcu_read_unlock();
1385 return ret;
1386 }
1387
1388 /*
1389 * Command LTTNG_UNTRACK_PID processed by the client thread.
1390 *
1391 * Called with session lock held.
1392 */
1393 int cmd_untrack_pid(struct ltt_session *session, enum lttng_domain_type domain,
1394 int pid)
1395 {
1396 int ret;
1397
1398 rcu_read_lock();
1399
1400 switch (domain) {
1401 case LTTNG_DOMAIN_KERNEL:
1402 {
1403 struct ltt_kernel_session *ksess;
1404
1405 ksess = session->kernel_session;
1406
1407 ret = kernel_untrack_pid(ksess, pid);
1408 if (ret != LTTNG_OK) {
1409 goto error;
1410 }
1411
1412 kernel_wait_quiescent(kernel_tracer_fd);
1413 break;
1414 }
1415 case LTTNG_DOMAIN_UST:
1416 {
1417 struct ltt_ust_session *usess;
1418
1419 usess = session->ust_session;
1420
1421 ret = trace_ust_untrack_pid(usess, pid);
1422 if (ret != LTTNG_OK) {
1423 goto error;
1424 }
1425 break;
1426 }
1427 default:
1428 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1429 goto error;
1430 }
1431
1432 ret = LTTNG_OK;
1433
1434 error:
1435 rcu_read_unlock();
1436 return ret;
1437 }
1438
1439 /*
1440 * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
1441 *
1442 * The wpipe arguments is used as a notifier for the kernel thread.
1443 */
1444 int cmd_enable_channel(struct ltt_session *session,
1445 struct lttng_domain *domain, struct lttng_channel *attr, int wpipe)
1446 {
1447 int ret;
1448 struct ltt_ust_session *usess = session->ust_session;
1449 struct lttng_ht *chan_ht;
1450 size_t len;
1451
1452 assert(session);
1453 assert(attr);
1454 assert(domain);
1455
1456 len = lttng_strnlen(attr->name, sizeof(attr->name));
1457
1458 /* Validate channel name */
1459 if (attr->name[0] == '.' ||
1460 memchr(attr->name, '/', len) != NULL) {
1461 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1462 goto end;
1463 }
1464
1465 DBG("Enabling channel %s for session %s", attr->name, session->name);
1466
1467 rcu_read_lock();
1468
1469 /*
1470 * Don't try to enable a channel if the session has been started at
1471 * some point in time before. The tracer does not allow it.
1472 */
1473 if (session->has_been_started) {
1474 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1475 goto error;
1476 }
1477
1478 /*
1479 * If the session is a live session, remove the switch timer, the
1480 * live timer does the same thing but sends also synchronisation
1481 * beacons for inactive streams.
1482 */
1483 if (session->live_timer > 0) {
1484 attr->attr.live_timer_interval = session->live_timer;
1485 attr->attr.switch_timer_interval = 0;
1486 }
1487
1488 /* Check for feature support */
1489 switch (domain->type) {
1490 case LTTNG_DOMAIN_KERNEL:
1491 {
1492 if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
1493 /* Sampling position of buffer is not supported */
1494 WARN("Kernel tracer does not support buffer monitoring. "
1495 "Setting the monitor interval timer to 0 "
1496 "(disabled) for channel '%s' of session '%s'",
1497 attr-> name, session->name);
1498 lttng_channel_set_monitor_timer_interval(attr, 0);
1499 }
1500 break;
1501 }
1502 case LTTNG_DOMAIN_UST:
1503 break;
1504 case LTTNG_DOMAIN_JUL:
1505 case LTTNG_DOMAIN_LOG4J:
1506 case LTTNG_DOMAIN_PYTHON:
1507 if (!agent_tracing_is_enabled()) {
1508 DBG("Attempted to enable a channel in an agent domain but the agent thread is not running");
1509 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1510 goto error;
1511 }
1512 break;
1513 default:
1514 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1515 goto error;
1516 }
1517
1518 switch (domain->type) {
1519 case LTTNG_DOMAIN_KERNEL:
1520 {
1521 struct ltt_kernel_channel *kchan;
1522
1523 kchan = trace_kernel_get_channel_by_name(attr->name,
1524 session->kernel_session);
1525 if (kchan == NULL) {
1526 if (session->snapshot.nb_output > 0 ||
1527 session->snapshot_mode) {
1528 /* Enforce mmap output for snapshot sessions. */
1529 attr->attr.output = LTTNG_EVENT_MMAP;
1530 }
1531 ret = channel_kernel_create(session->kernel_session, attr, wpipe);
1532 if (attr->name[0] != '\0') {
1533 session->kernel_session->has_non_default_channel = 1;
1534 }
1535 } else {
1536 ret = channel_kernel_enable(session->kernel_session, kchan);
1537 }
1538
1539 if (ret != LTTNG_OK) {
1540 goto error;
1541 }
1542
1543 kernel_wait_quiescent(kernel_tracer_fd);
1544 break;
1545 }
1546 case LTTNG_DOMAIN_UST:
1547 case LTTNG_DOMAIN_JUL:
1548 case LTTNG_DOMAIN_LOG4J:
1549 case LTTNG_DOMAIN_PYTHON:
1550 {
1551 struct ltt_ust_channel *uchan;
1552
1553 /*
1554 * FIXME
1555 *
1556 * Current agent implementation limitations force us to allow
1557 * only one channel at once in "agent" subdomains. Each
1558 * subdomain has a default channel name which must be strictly
1559 * adhered to.
1560 */
1561 if (domain->type == LTTNG_DOMAIN_JUL) {
1562 if (strncmp(attr->name, DEFAULT_JUL_CHANNEL_NAME,
1563 LTTNG_SYMBOL_NAME_LEN)) {
1564 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1565 goto error;
1566 }
1567 } else if (domain->type == LTTNG_DOMAIN_LOG4J) {
1568 if (strncmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME,
1569 LTTNG_SYMBOL_NAME_LEN)) {
1570 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1571 goto error;
1572 }
1573 } else if (domain->type == LTTNG_DOMAIN_PYTHON) {
1574 if (strncmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME,
1575 LTTNG_SYMBOL_NAME_LEN)) {
1576 ret = LTTNG_ERR_INVALID_CHANNEL_NAME;
1577 goto error;
1578 }
1579 }
1580
1581 chan_ht = usess->domain_global.channels;
1582
1583 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
1584 if (uchan == NULL) {
1585 ret = channel_ust_create(usess, attr, domain->buf_type);
1586 if (attr->name[0] != '\0') {
1587 usess->has_non_default_channel = 1;
1588 }
1589 } else {
1590 ret = channel_ust_enable(usess, uchan);
1591 }
1592 break;
1593 }
1594 default:
1595 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1596 goto error;
1597 }
1598
1599 if (ret == LTTNG_OK && attr->attr.output != LTTNG_EVENT_MMAP) {
1600 session->has_non_mmap_channel = true;
1601 }
1602 error:
1603 rcu_read_unlock();
1604 end:
1605 return ret;
1606 }
1607
1608 /*
1609 * Command LTTNG_DISABLE_EVENT processed by the client thread.
1610 */
1611 int cmd_disable_event(struct ltt_session *session,
1612 enum lttng_domain_type domain, char *channel_name,
1613 struct lttng_event *event)
1614 {
1615 int ret;
1616 char *event_name;
1617
1618 DBG("Disable event command for event \'%s\'", event->name);
1619
1620 event_name = event->name;
1621
1622 /* Error out on unhandled search criteria */
1623 if (event->loglevel_type || event->loglevel != -1 || event->enabled
1624 || event->pid || event->filter || event->exclusion) {
1625 ret = LTTNG_ERR_UNK;
1626 goto error;
1627 }
1628
1629 rcu_read_lock();
1630
1631 switch (domain) {
1632 case LTTNG_DOMAIN_KERNEL:
1633 {
1634 struct ltt_kernel_channel *kchan;
1635 struct ltt_kernel_session *ksess;
1636
1637 ksess = session->kernel_session;
1638
1639 /*
1640 * If a non-default channel has been created in the
1641 * session, explicitely require that -c chan_name needs
1642 * to be provided.
1643 */
1644 if (ksess->has_non_default_channel && channel_name[0] == '\0') {
1645 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1646 goto error_unlock;
1647 }
1648
1649 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
1650 if (kchan == NULL) {
1651 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
1652 goto error_unlock;
1653 }
1654
1655 switch (event->type) {
1656 case LTTNG_EVENT_ALL:
1657 case LTTNG_EVENT_TRACEPOINT:
1658 case LTTNG_EVENT_SYSCALL:
1659 case LTTNG_EVENT_PROBE:
1660 case LTTNG_EVENT_FUNCTION:
1661 case LTTNG_EVENT_FUNCTION_ENTRY:/* fall-through */
1662 if (event_name[0] == '\0') {
1663 ret = event_kernel_disable_event(kchan,
1664 NULL, event->type);
1665 } else {
1666 ret = event_kernel_disable_event(kchan,
1667 event_name, event->type);
1668 }
1669 if (ret != LTTNG_OK) {
1670 goto error_unlock;
1671 }
1672 break;
1673 default:
1674 ret = LTTNG_ERR_UNK;
1675 goto error_unlock;
1676 }
1677
1678 kernel_wait_quiescent(kernel_tracer_fd);
1679 break;
1680 }
1681 case LTTNG_DOMAIN_UST:
1682 {
1683 struct ltt_ust_channel *uchan;
1684 struct ltt_ust_session *usess;
1685
1686 usess = session->ust_session;
1687
1688 if (validate_ust_event_name(event_name)) {
1689 ret = LTTNG_ERR_INVALID_EVENT_NAME;
1690 goto error_unlock;
1691 }
1692
1693 /*
1694 * If a non-default channel has been created in the
1695 * session, explicitly require that -c chan_name needs
1696 * to be provided.
1697 */
1698 if (usess->has_non_default_channel && channel_name[0] == '\0') {
1699 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
1700 goto error_unlock;
1701 }
1702
1703 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1704 channel_name);
1705 if (uchan == NULL) {
1706 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1707 goto error_unlock;
1708 }
1709
1710 switch (event->type) {
1711 case LTTNG_EVENT_ALL:
1712 /*
1713 * An empty event name means that everything
1714 * should be disabled.
1715 */
1716 if (event->name[0] == '\0') {
1717 ret = event_ust_disable_all_tracepoints(usess, uchan);
1718 } else {
1719 ret = event_ust_disable_tracepoint(usess, uchan,
1720 event_name);
1721 }
1722 if (ret != LTTNG_OK) {
1723 goto error_unlock;
1724 }
1725 break;
1726 default:
1727 ret = LTTNG_ERR_UNK;
1728 goto error_unlock;
1729 }
1730
1731 DBG3("Disable UST event %s in channel %s completed", event_name,
1732 channel_name);
1733 break;
1734 }
1735 case LTTNG_DOMAIN_LOG4J:
1736 case LTTNG_DOMAIN_JUL:
1737 case LTTNG_DOMAIN_PYTHON:
1738 {
1739 struct agent *agt;
1740 struct ltt_ust_session *usess = session->ust_session;
1741
1742 assert(usess);
1743
1744 switch (event->type) {
1745 case LTTNG_EVENT_ALL:
1746 break;
1747 default:
1748 ret = LTTNG_ERR_UNK;
1749 goto error_unlock;
1750 }
1751
1752 agt = trace_ust_find_agent(usess, domain);
1753 if (!agt) {
1754 ret = -LTTNG_ERR_UST_EVENT_NOT_FOUND;
1755 goto error_unlock;
1756 }
1757 /*
1758 * An empty event name means that everything
1759 * should be disabled.
1760 */
1761 if (event->name[0] == '\0') {
1762 ret = event_agent_disable_all(usess, agt);
1763 } else {
1764 ret = event_agent_disable(usess, agt, event_name);
1765 }
1766 if (ret != LTTNG_OK) {
1767 goto error_unlock;
1768 }
1769
1770 break;
1771 }
1772 default:
1773 ret = LTTNG_ERR_UND;
1774 goto error_unlock;
1775 }
1776
1777 ret = LTTNG_OK;
1778
1779 error_unlock:
1780 rcu_read_unlock();
1781 error:
1782 return ret;
1783 }
1784
1785 /*
1786 * Command LTTNG_ADD_CONTEXT processed by the client thread.
1787 */
1788 int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
1789 char *channel_name, struct lttng_event_context *ctx, int kwpipe)
1790 {
1791 int ret, chan_kern_created = 0, chan_ust_created = 0;
1792 char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
1793
1794 /*
1795 * Don't try to add a context if the session has been started at
1796 * some point in time before. The tracer does not allow it and would
1797 * result in a corrupted trace.
1798 */
1799 if (session->has_been_started) {
1800 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
1801 goto end;
1802 }
1803
1804 if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1805 app_ctx_provider_name = ctx->u.app_ctx.provider_name;
1806 app_ctx_name = ctx->u.app_ctx.ctx_name;
1807 }
1808
1809 switch (domain) {
1810 case LTTNG_DOMAIN_KERNEL:
1811 assert(session->kernel_session);
1812
1813 if (session->kernel_session->channel_count == 0) {
1814 /* Create default channel */
1815 ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
1816 if (ret != LTTNG_OK) {
1817 goto error;
1818 }
1819 chan_kern_created = 1;
1820 }
1821 /* Add kernel context to kernel tracer */
1822 ret = context_kernel_add(session->kernel_session, ctx, channel_name);
1823 if (ret != LTTNG_OK) {
1824 goto error;
1825 }
1826 break;
1827 case LTTNG_DOMAIN_JUL:
1828 case LTTNG_DOMAIN_LOG4J:
1829 {
1830 /*
1831 * Validate channel name.
1832 * If no channel name is given and the domain is JUL or LOG4J,
1833 * set it to the appropriate domain-specific channel name. If
1834 * a name is provided but does not match the expexted channel
1835 * name, return an error.
1836 */
1837 if (domain == LTTNG_DOMAIN_JUL && *channel_name &&
1838 strcmp(channel_name,
1839 DEFAULT_JUL_CHANNEL_NAME)) {
1840 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1841 goto error;
1842 } else if (domain == LTTNG_DOMAIN_LOG4J && *channel_name &&
1843 strcmp(channel_name,
1844 DEFAULT_LOG4J_CHANNEL_NAME)) {
1845 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1846 goto error;
1847 }
1848 /* break is _not_ missing here. */
1849 }
1850 case LTTNG_DOMAIN_UST:
1851 {
1852 struct ltt_ust_session *usess = session->ust_session;
1853 unsigned int chan_count;
1854
1855 assert(usess);
1856
1857 chan_count = lttng_ht_get_count(usess->domain_global.channels);
1858 if (chan_count == 0) {
1859 struct lttng_channel *attr;
1860 /* Create default channel */
1861 attr = channel_new_default_attr(domain, usess->buffer_type);
1862 if (attr == NULL) {
1863 ret = LTTNG_ERR_FATAL;
1864 goto error;
1865 }
1866
1867 ret = channel_ust_create(usess, attr, usess->buffer_type);
1868 if (ret != LTTNG_OK) {
1869 free(attr);
1870 goto error;
1871 }
1872 channel_attr_destroy(attr);
1873 chan_ust_created = 1;
1874 }
1875
1876 ret = context_ust_add(usess, domain, ctx, channel_name);
1877 free(app_ctx_provider_name);
1878 free(app_ctx_name);
1879 app_ctx_name = NULL;
1880 app_ctx_provider_name = NULL;
1881 if (ret != LTTNG_OK) {
1882 goto error;
1883 }
1884 break;
1885 }
1886 default:
1887 ret = LTTNG_ERR_UND;
1888 goto error;
1889 }
1890
1891 ret = LTTNG_OK;
1892 goto end;
1893
1894 error:
1895 if (chan_kern_created) {
1896 struct ltt_kernel_channel *kchan =
1897 trace_kernel_get_channel_by_name(DEFAULT_CHANNEL_NAME,
1898 session->kernel_session);
1899 /* Created previously, this should NOT fail. */
1900 assert(kchan);
1901 kernel_destroy_channel(kchan);
1902 }
1903
1904 if (chan_ust_created) {
1905 struct ltt_ust_channel *uchan =
1906 trace_ust_find_channel_by_name(
1907 session->ust_session->domain_global.channels,
1908 DEFAULT_CHANNEL_NAME);
1909 /* Created previously, this should NOT fail. */
1910 assert(uchan);
1911 /* Remove from the channel list of the session. */
1912 trace_ust_delete_channel(session->ust_session->domain_global.channels,
1913 uchan);
1914 trace_ust_destroy_channel(uchan);
1915 }
1916 end:
1917 free(app_ctx_provider_name);
1918 free(app_ctx_name);
1919 return ret;
1920 }
1921
1922 static inline bool name_starts_with(const char *name, const char *prefix)
1923 {
1924 const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
1925
1926 return !strncmp(name, prefix, max_cmp_len);
1927 }
1928
1929 /* Perform userspace-specific event name validation */
1930 static int validate_ust_event_name(const char *name)
1931 {
1932 int ret = 0;
1933
1934 if (!name) {
1935 ret = -1;
1936 goto end;
1937 }
1938
1939 /*
1940 * Check name against all internal UST event component namespaces used
1941 * by the agents.
1942 */
1943 if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
1944 name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
1945 name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
1946 ret = -1;
1947 }
1948
1949 end:
1950 return ret;
1951 }
1952
1953 /*
1954 * Internal version of cmd_enable_event() with a supplemental
1955 * "internal_event" flag which is used to enable internal events which should
1956 * be hidden from clients. Such events are used in the agent implementation to
1957 * enable the events through which all "agent" events are funeled.
1958 */
1959 static int _cmd_enable_event(struct ltt_session *session,
1960 struct lttng_domain *domain,
1961 char *channel_name, struct lttng_event *event,
1962 char *filter_expression,
1963 struct lttng_filter_bytecode *filter,
1964 struct lttng_event_exclusion *exclusion,
1965 int wpipe, bool internal_event)
1966 {
1967 int ret = 0, channel_created = 0;
1968 struct lttng_channel *attr = NULL;
1969
1970 assert(session);
1971 assert(event);
1972 assert(channel_name);
1973
1974 /* If we have a filter, we must have its filter expression */
1975 assert(!(!!filter_expression ^ !!filter));
1976
1977 /* Normalize event name as a globbing pattern */
1978 strutils_normalize_star_glob_pattern(event->name);
1979
1980 /* Normalize exclusion names as globbing patterns */
1981 if (exclusion) {
1982 size_t i;
1983
1984 for (i = 0; i < exclusion->count; i++) {
1985 char *name = LTTNG_EVENT_EXCLUSION_NAME_AT(exclusion, i);
1986
1987 strutils_normalize_star_glob_pattern(name);
1988 }
1989 }
1990
1991 DBG("Enable event command for event \'%s\'", event->name);
1992
1993 rcu_read_lock();
1994
1995 switch (domain->type) {
1996 case LTTNG_DOMAIN_KERNEL:
1997 {
1998 struct ltt_kernel_channel *kchan;
1999
2000 /*
2001 * If a non-default channel has been created in the
2002 * session, explicitely require that -c chan_name needs
2003 * to be provided.
2004 */
2005 if (session->kernel_session->has_non_default_channel
2006 && channel_name[0] == '\0') {
2007 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2008 goto error;
2009 }
2010
2011 kchan = trace_kernel_get_channel_by_name(channel_name,
2012 session->kernel_session);
2013 if (kchan == NULL) {
2014 attr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
2015 LTTNG_BUFFER_GLOBAL);
2016 if (attr == NULL) {
2017 ret = LTTNG_ERR_FATAL;
2018 goto error;
2019 }
2020 if (lttng_strncpy(attr->name, channel_name,
2021 sizeof(attr->name))) {
2022 ret = LTTNG_ERR_INVALID;
2023 goto error;
2024 }
2025
2026 ret = cmd_enable_channel(session, domain, attr, wpipe);
2027 if (ret != LTTNG_OK) {
2028 goto error;
2029 }
2030 channel_created = 1;
2031 }
2032
2033 /* Get the newly created kernel channel pointer */
2034 kchan = trace_kernel_get_channel_by_name(channel_name,
2035 session->kernel_session);
2036 if (kchan == NULL) {
2037 /* This sould not happen... */
2038 ret = LTTNG_ERR_FATAL;
2039 goto error;
2040 }
2041
2042 switch (event->type) {
2043 case LTTNG_EVENT_ALL:
2044 {
2045 char *filter_expression_a = NULL;
2046 struct lttng_filter_bytecode *filter_a = NULL;
2047
2048 /*
2049 * We need to duplicate filter_expression and filter,
2050 * because ownership is passed to first enable
2051 * event.
2052 */
2053 if (filter_expression) {
2054 filter_expression_a = strdup(filter_expression);
2055 if (!filter_expression_a) {
2056 ret = LTTNG_ERR_FATAL;
2057 goto error;
2058 }
2059 }
2060 if (filter) {
2061 filter_a = zmalloc(sizeof(*filter_a) + filter->len);
2062 if (!filter_a) {
2063 free(filter_expression_a);
2064 ret = LTTNG_ERR_FATAL;
2065 goto error;
2066 }
2067 memcpy(filter_a, filter, sizeof(*filter_a) + filter->len);
2068 }
2069 event->type = LTTNG_EVENT_TRACEPOINT; /* Hack */
2070 ret = event_kernel_enable_event(kchan, event,
2071 filter_expression, filter);
2072 /* We have passed ownership */
2073 filter_expression = NULL;
2074 filter = NULL;
2075 if (ret != LTTNG_OK) {
2076 if (channel_created) {
2077 /* Let's not leak a useless channel. */
2078 kernel_destroy_channel(kchan);
2079 }
2080 free(filter_expression_a);
2081 free(filter_a);
2082 goto error;
2083 }
2084 event->type = LTTNG_EVENT_SYSCALL; /* Hack */
2085 ret = event_kernel_enable_event(kchan, event,
2086 filter_expression_a, filter_a);
2087 /* We have passed ownership */
2088 filter_expression_a = NULL;
2089 filter_a = NULL;
2090 if (ret != LTTNG_OK) {
2091 goto error;
2092 }
2093 break;
2094 }
2095 case LTTNG_EVENT_PROBE:
2096 case LTTNG_EVENT_USERSPACE_PROBE:
2097 case LTTNG_EVENT_FUNCTION:
2098 case LTTNG_EVENT_FUNCTION_ENTRY:
2099 case LTTNG_EVENT_TRACEPOINT:
2100 ret = event_kernel_enable_event(kchan, event,
2101 filter_expression, filter);
2102 /* We have passed ownership */
2103 filter_expression = NULL;
2104 filter = NULL;
2105 if (ret != LTTNG_OK) {
2106 if (channel_created) {
2107 /* Let's not leak a useless channel. */
2108 kernel_destroy_channel(kchan);
2109 }
2110 goto error;
2111 }
2112 break;
2113 case LTTNG_EVENT_SYSCALL:
2114 ret = event_kernel_enable_event(kchan, event,
2115 filter_expression, filter);
2116 /* We have passed ownership */
2117 filter_expression = NULL;
2118 filter = NULL;
2119 if (ret != LTTNG_OK) {
2120 goto error;
2121 }
2122 break;
2123 default:
2124 ret = LTTNG_ERR_UNK;
2125 goto error;
2126 }
2127
2128 kernel_wait_quiescent(kernel_tracer_fd);
2129 break;
2130 }
2131 case LTTNG_DOMAIN_UST:
2132 {
2133 struct ltt_ust_channel *uchan;
2134 struct ltt_ust_session *usess = session->ust_session;
2135
2136 assert(usess);
2137
2138 /*
2139 * If a non-default channel has been created in the
2140 * session, explicitely require that -c chan_name needs
2141 * to be provided.
2142 */
2143 if (usess->has_non_default_channel && channel_name[0] == '\0') {
2144 ret = LTTNG_ERR_NEED_CHANNEL_NAME;
2145 goto error;
2146 }
2147
2148 /* Get channel from global UST domain */
2149 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
2150 channel_name);
2151 if (uchan == NULL) {
2152 /* Create default channel */
2153 attr = channel_new_default_attr(LTTNG_DOMAIN_UST,
2154 usess->buffer_type);
2155 if (attr == NULL) {
2156 ret = LTTNG_ERR_FATAL;
2157 goto error;
2158 }
2159 if (lttng_strncpy(attr->name, channel_name,
2160 sizeof(attr->name))) {
2161 ret = LTTNG_ERR_INVALID;
2162 goto error;
2163 }
2164
2165 ret = cmd_enable_channel(session, domain, attr, wpipe);
2166 if (ret != LTTNG_OK) {
2167 goto error;
2168 }
2169
2170 /* Get the newly created channel reference back */
2171 uchan = trace_ust_find_channel_by_name(
2172 usess->domain_global.channels, channel_name);
2173 assert(uchan);
2174 }
2175
2176 if (uchan->domain != LTTNG_DOMAIN_UST && !internal_event) {
2177 /*
2178 * Don't allow users to add UST events to channels which
2179 * are assigned to a userspace subdomain (JUL, Log4J,
2180 * Python, etc.).
2181 */
2182 ret = LTTNG_ERR_INVALID_CHANNEL_DOMAIN;
2183 goto error;
2184 }
2185
2186 if (!internal_event) {
2187 /*
2188 * Ensure the event name is not reserved for internal
2189 * use.
2190 */
2191 ret = validate_ust_event_name(event->name);
2192 if (ret) {
2193 WARN("Userspace event name %s failed validation.",
2194 event->name);
2195 ret = LTTNG_ERR_INVALID_EVENT_NAME;
2196 goto error;
2197 }
2198 }
2199
2200 /* At this point, the session and channel exist on the tracer */
2201 ret = event_ust_enable_tracepoint(usess, uchan, event,
2202 filter_expression, filter, exclusion,
2203 internal_event);
2204 /* We have passed ownership */
2205 filter_expression = NULL;
2206 filter = NULL;
2207 exclusion = NULL;
2208 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2209 goto already_enabled;
2210 } else if (ret != LTTNG_OK) {
2211 goto error;
2212 }
2213 break;
2214 }
2215 case LTTNG_DOMAIN_LOG4J:
2216 case LTTNG_DOMAIN_JUL:
2217 case LTTNG_DOMAIN_PYTHON:
2218 {
2219 const char *default_event_name, *default_chan_name;
2220 struct agent *agt;
2221 struct lttng_event uevent;
2222 struct lttng_domain tmp_dom;
2223 struct ltt_ust_session *usess = session->ust_session;
2224
2225 assert(usess);
2226
2227 if (!agent_tracing_is_enabled()) {
2228 DBG("Attempted to enable an event in an agent domain but the agent thread is not running");
2229 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
2230 goto error;
2231 }
2232
2233 agt = trace_ust_find_agent(usess, domain->type);
2234 if (!agt) {
2235 agt = agent_create(domain->type);
2236 if (!agt) {
2237 ret = LTTNG_ERR_NOMEM;
2238 goto error;
2239 }
2240 agent_add(agt, usess->agents);
2241 }
2242
2243 /* Create the default tracepoint. */
2244 memset(&uevent, 0, sizeof(uevent));
2245 uevent.type = LTTNG_EVENT_TRACEPOINT;
2246 uevent.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
2247 default_event_name = event_get_default_agent_ust_name(
2248 domain->type);
2249 if (!default_event_name) {
2250 ret = LTTNG_ERR_FATAL;
2251 goto error;
2252 }
2253 strncpy(uevent.name, default_event_name, sizeof(uevent.name));
2254 uevent.name[sizeof(uevent.name) - 1] = '\0';
2255
2256 /*
2257 * The domain type is changed because we are about to enable the
2258 * default channel and event for the JUL domain that are hardcoded.
2259 * This happens in the UST domain.
2260 */
2261 memcpy(&tmp_dom, domain, sizeof(tmp_dom));
2262 tmp_dom.type = LTTNG_DOMAIN_UST;
2263
2264 switch (domain->type) {
2265 case LTTNG_DOMAIN_LOG4J:
2266 default_chan_name = DEFAULT_LOG4J_CHANNEL_NAME;
2267 break;
2268 case LTTNG_DOMAIN_JUL:
2269 default_chan_name = DEFAULT_JUL_CHANNEL_NAME;
2270 break;
2271 case LTTNG_DOMAIN_PYTHON:
2272 default_chan_name = DEFAULT_PYTHON_CHANNEL_NAME;
2273 break;
2274 default:
2275 /* The switch/case we are in makes this impossible */
2276 assert(0);
2277 }
2278
2279 {
2280 char *filter_expression_copy = NULL;
2281 struct lttng_filter_bytecode *filter_copy = NULL;
2282
2283 if (filter) {
2284 const size_t filter_size = sizeof(
2285 struct lttng_filter_bytecode)
2286 + filter->len;
2287
2288 filter_copy = zmalloc(filter_size);
2289 if (!filter_copy) {
2290 ret = LTTNG_ERR_NOMEM;
2291 goto error;
2292 }
2293 memcpy(filter_copy, filter, filter_size);
2294
2295 filter_expression_copy =
2296 strdup(filter_expression);
2297 if (!filter_expression) {
2298 ret = LTTNG_ERR_NOMEM;
2299 }
2300
2301 if (!filter_expression_copy || !filter_copy) {
2302 free(filter_expression_copy);
2303 free(filter_copy);
2304 goto error;
2305 }
2306 }
2307
2308 ret = cmd_enable_event_internal(session, &tmp_dom,
2309 (char *) default_chan_name,
2310 &uevent, filter_expression_copy,
2311 filter_copy, NULL, wpipe);
2312 }
2313
2314 if (ret == LTTNG_ERR_UST_EVENT_ENABLED) {
2315 goto already_enabled;
2316 } else if (ret != LTTNG_OK) {
2317 goto error;
2318 }
2319
2320 /* The wild card * means that everything should be enabled. */
2321 if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
2322 ret = event_agent_enable_all(usess, agt, event, filter,
2323 filter_expression);
2324 } else {
2325 ret = event_agent_enable(usess, agt, event, filter,
2326 filter_expression);
2327 }
2328 filter = NULL;
2329 filter_expression = NULL;
2330 if (ret != LTTNG_OK) {
2331 goto error;
2332 }
2333
2334 break;
2335 }
2336 default:
2337 ret = LTTNG_ERR_UND;
2338 goto error;
2339 }
2340
2341 ret = LTTNG_OK;
2342
2343 already_enabled:
2344 error:
2345 free(filter_expression);
2346 free(filter);
2347 free(exclusion);
2348 channel_attr_destroy(attr);
2349 rcu_read_unlock();
2350 return ret;
2351 }
2352
2353 /*
2354 * Command LTTNG_ENABLE_EVENT processed by the client thread.
2355 * We own filter, exclusion, and filter_expression.
2356 */
2357 int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
2358 char *channel_name, struct lttng_event *event,
2359 char *filter_expression,
2360 struct lttng_filter_bytecode *filter,
2361 struct lttng_event_exclusion *exclusion,
2362 int wpipe)
2363 {
2364 return _cmd_enable_event(session, domain, channel_name, event,
2365 filter_expression, filter, exclusion, wpipe, false);
2366 }
2367
2368 /*
2369 * Enable an event which is internal to LTTng. An internal should
2370 * never be made visible to clients and are immune to checks such as
2371 * reserved names.
2372 */
2373 static int cmd_enable_event_internal(struct ltt_session *session,
2374 struct lttng_domain *domain,
2375 char *channel_name, struct lttng_event *event,
2376 char *filter_expression,
2377 struct lttng_filter_bytecode *filter,
2378 struct lttng_event_exclusion *exclusion,
2379 int wpipe)
2380 {
2381 return _cmd_enable_event(session, domain, channel_name, event,
2382 filter_expression, filter, exclusion, wpipe, true);
2383 }
2384
2385 /*
2386 * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
2387 */
2388 ssize_t cmd_list_tracepoints(enum lttng_domain_type domain,
2389 struct lttng_event **events)
2390 {
2391 int ret;
2392 ssize_t nb_events = 0;
2393
2394 switch (domain) {
2395 case LTTNG_DOMAIN_KERNEL:
2396 nb_events = kernel_list_events(kernel_tracer_fd, events);
2397 if (nb_events < 0) {
2398 ret = LTTNG_ERR_KERN_LIST_FAIL;
2399 goto error;
2400 }
2401 break;
2402 case LTTNG_DOMAIN_UST:
2403 nb_events = ust_app_list_events(events);
2404 if (nb_events < 0) {
2405 ret = LTTNG_ERR_UST_LIST_FAIL;
2406 goto error;
2407 }
2408 break;
2409 case LTTNG_DOMAIN_LOG4J:
2410 case LTTNG_DOMAIN_JUL:
2411 case LTTNG_DOMAIN_PYTHON:
2412 nb_events = agent_list_events(events, domain);
2413 if (nb_events < 0) {
2414 ret = LTTNG_ERR_UST_LIST_FAIL;
2415 goto error;
2416 }
2417 break;
2418 default:
2419 ret = LTTNG_ERR_UND;
2420 goto error;
2421 }
2422
2423 return nb_events;
2424
2425 error:
2426 /* Return negative value to differentiate return code */
2427 return -ret;
2428 }
2429
2430 /*
2431 * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
2432 */
2433 ssize_t cmd_list_tracepoint_fields(enum lttng_domain_type domain,
2434 struct lttng_event_field **fields)
2435 {
2436 int ret;
2437 ssize_t nb_fields = 0;
2438
2439 switch (domain) {
2440 case LTTNG_DOMAIN_UST:
2441 nb_fields = ust_app_list_event_fields(fields);
2442 if (nb_fields < 0) {
2443 ret = LTTNG_ERR_UST_LIST_FAIL;
2444 goto error;
2445 }
2446 break;
2447 case LTTNG_DOMAIN_KERNEL:
2448 default: /* fall-through */
2449 ret = LTTNG_ERR_UND;
2450 goto error;
2451 }
2452
2453 return nb_fields;
2454
2455 error:
2456 /* Return negative value to differentiate return code */
2457 return -ret;
2458 }
2459
2460 ssize_t cmd_list_syscalls(struct lttng_event **events)
2461 {
2462 return syscall_table_list(events);
2463 }
2464
2465 /*
2466 * Command LTTNG_LIST_TRACKER_PIDS processed by the client thread.
2467 *
2468 * Called with session lock held.
2469 */
2470 ssize_t cmd_list_tracker_pids(struct ltt_session *session,
2471 enum lttng_domain_type domain, int32_t **pids)
2472 {
2473 int ret;
2474 ssize_t nr_pids = 0;
2475
2476 switch (domain) {
2477 case LTTNG_DOMAIN_KERNEL:
2478 {
2479 struct ltt_kernel_session *ksess;
2480
2481 ksess = session->kernel_session;
2482 nr_pids = kernel_list_tracker_pids(ksess, pids);
2483 if (nr_pids < 0) {
2484 ret = LTTNG_ERR_KERN_LIST_FAIL;
2485 goto error;
2486 }
2487 break;
2488 }
2489 case LTTNG_DOMAIN_UST:
2490 {
2491 struct ltt_ust_session *usess;
2492
2493 usess = session->ust_session;
2494 nr_pids = trace_ust_list_tracker_pids(usess, pids);
2495 if (nr_pids < 0) {
2496 ret = LTTNG_ERR_UST_LIST_FAIL;
2497 goto error;
2498 }
2499 break;
2500 }
2501 case LTTNG_DOMAIN_LOG4J:
2502 case LTTNG_DOMAIN_JUL:
2503 case LTTNG_DOMAIN_PYTHON:
2504 default:
2505 ret = LTTNG_ERR_UND;
2506 goto error;
2507 }
2508
2509 return nr_pids;
2510
2511 error:
2512 /* Return negative value to differentiate return code */
2513 return -ret;
2514 }
2515
2516 static
2517 int domain_mkdir(const struct consumer_output *output,
2518 const struct ltt_session *session,
2519 uid_t uid, gid_t gid)
2520 {
2521 struct consumer_socket *socket;
2522 struct lttng_ht_iter iter;
2523 int ret;
2524 char *path = NULL;
2525
2526 if (!output || !output->socks) {
2527 ERR("No consumer output found");
2528 ret = -1;
2529 goto end;
2530 }
2531
2532 path = zmalloc(LTTNG_PATH_MAX * sizeof(char));
2533 if (!path) {
2534 ERR("Cannot allocate mkdir path");
2535 ret = -1;
2536 goto end;
2537 }
2538
2539 ret = snprintf(path, LTTNG_PATH_MAX, "%s%s%s",
2540 session_get_base_path(session),
2541 output->chunk_path, output->subdir);
2542 if (ret < 0 || ret >= LTTNG_PATH_MAX) {
2543 ERR("Format path");
2544 ret = -1;
2545 goto end;
2546 }
2547
2548 DBG("Domain mkdir %s for session %" PRIu64, path, session->id);
2549 rcu_read_lock();
2550 /*
2551 * We have to iterate to find a socket, but we only need to send the
2552 * rename command to one consumer, so we break after the first one.
2553 */
2554 cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
2555 pthread_mutex_lock(socket->lock);
2556 ret = consumer_mkdir(socket, session->id, output, path, uid, gid);
2557 pthread_mutex_unlock(socket->lock);
2558 if (ret) {
2559 ERR("Consumer mkdir");
2560 ret = -1;
2561 goto end_unlock;
2562 }
2563 break;
2564 }
2565
2566 ret = 0;
2567
2568 end_unlock:
2569 rcu_read_unlock();
2570 end:
2571 free(path);
2572 return ret;
2573 }
2574
2575 static
2576 int session_mkdir(const struct ltt_session *session)
2577 {
2578 int ret;
2579 struct consumer_output *output;
2580 uid_t uid;
2581 gid_t gid;
2582
2583 /*
2584 * Unsupported feature in lttng-relayd before 2.11, not an error since it
2585 * is only needed for session rotation and the user will get an error
2586 * on rotate.
2587 */
2588 if (session->consumer->type == CONSUMER_DST_NET &&
2589 session->consumer->relay_major_version == 2 &&
2590 session->consumer->relay_minor_version < 11) {
2591 ret = 0;
2592 goto end;
2593 }
2594
2595 if (session->kernel_session) {
2596 output = session->kernel_session->consumer;
2597 uid = session->kernel_session->uid;
2598 gid = session->kernel_session->gid;
2599 ret = domain_mkdir(output, session, uid, gid);
2600 if (ret) {
2601 ERR("Mkdir kernel");
2602 goto end;
2603 }
2604 }
2605
2606 if (session->ust_session) {
2607 output = session->ust_session->consumer;
2608 uid = session->ust_session->uid;
2609 gid = session->ust_session->gid;
2610 ret = domain_mkdir(output, session, uid, gid);
2611 if (ret) {
2612 ERR("Mkdir UST");
2613 goto end;
2614 }
2615 }
2616
2617 ret = 0;
2618
2619 end:
2620 return ret;
2621 }
2622
2623 /*
2624 * Command LTTNG_START_TRACE processed by the client thread.
2625 *
2626 * Called with session mutex held.
2627 */
2628 int cmd_start_trace(struct ltt_session *session)
2629 {
2630 int ret;
2631 unsigned long nb_chan = 0;
2632 struct ltt_kernel_session *ksession;
2633 struct ltt_ust_session *usess;
2634
2635 assert(session);
2636
2637 /* Ease our life a bit ;) */
2638 ksession = session->kernel_session;
2639 usess = session->ust_session;
2640
2641 /* Is the session already started? */
2642 if (session->active) {
2643 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2644 goto error;
2645 }
2646
2647 /*
2648 * Starting a session without channel is useless since after that it's not
2649 * possible to enable channel thus inform the client.
2650 */
2651 if (usess && usess->domain_global.channels) {
2652 nb_chan += lttng_ht_get_count(usess->domain_global.channels);
2653 }
2654 if (ksession) {
2655 nb_chan += ksession->channel_count;
2656 }
2657 if (!nb_chan) {
2658 ret = LTTNG_ERR_NO_CHANNEL;
2659 goto error;
2660 }
2661
2662 /*
2663 * Record the timestamp of the first time the session is started for
2664 * an eventual session rotation call.
2665 */
2666 if (!session->has_been_started) {
2667 session->current_chunk_start_ts = time(NULL);
2668 if (session->current_chunk_start_ts == (time_t) -1) {
2669 PERROR("Failed to retrieve the \"%s\" session's start time",
2670 session->name);
2671 ret = LTTNG_ERR_FATAL;
2672 goto error;
2673 }
2674 if (!session->snapshot_mode && session->output_traces) {
2675 ret = session_mkdir(session);
2676 if (ret) {
2677 ERR("Failed to create the session directories");
2678 ret = LTTNG_ERR_CREATE_DIR_FAIL;
2679 goto error;
2680 }
2681 }
2682 }
2683
2684 /* Kernel tracing */
2685 if (ksession != NULL) {
2686 DBG("Start kernel tracing session %s", session->name);
2687 ret = start_kernel_session(ksession, kernel_tracer_fd);
2688 if (ret != LTTNG_OK) {
2689 goto error;
2690 }
2691 }
2692
2693 /* Flag session that trace should start automatically */
2694 if (usess) {
2695 ret = ust_app_start_trace_all(usess);
2696 if (ret < 0) {
2697 ret = LTTNG_ERR_UST_START_FAIL;
2698 goto error;
2699 }
2700 }
2701
2702 /* Flag this after a successful start. */
2703 session->has_been_started = 1;
2704 session->active = 1;
2705
2706 /*
2707 * Clear the flag that indicates that a rotation was done while the
2708 * session was stopped.
2709 */
2710 session->rotated_after_last_stop = false;
2711
2712 if (session->rotate_timer_period) {
2713 ret = timer_session_rotation_schedule_timer_start(session,
2714 session->rotate_timer_period);
2715 if (ret < 0) {
2716 ERR("Failed to enable rotate timer");
2717 ret = LTTNG_ERR_UNK;
2718 goto error;
2719 }
2720 }
2721
2722 ret = LTTNG_OK;
2723
2724 error:
2725 return ret;
2726 }
2727
2728 /*
2729 * Command LTTNG_STOP_TRACE processed by the client thread.
2730 */
2731 int cmd_stop_trace(struct ltt_session *session)
2732 {
2733 int ret;
2734 struct ltt_kernel_channel *kchan;
2735 struct ltt_kernel_session *ksession;
2736 struct ltt_ust_session *usess;
2737 bool error_occurred = false;
2738
2739 assert(session);
2740
2741 DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
2742 /* Short cut */
2743 ksession = session->kernel_session;
2744 usess = session->ust_session;
2745
2746 /* Session is not active. Skip everythong and inform the client. */
2747 if (!session->active) {
2748 ret = LTTNG_ERR_TRACE_ALREADY_STOPPED;
2749 goto error;
2750 }
2751
2752 /* Kernel tracer */
2753 if (ksession && ksession->active) {
2754 DBG("Stop kernel tracing");
2755
2756 ret = kernel_stop_session(ksession);
2757 if (ret < 0) {
2758 ret = LTTNG_ERR_KERN_STOP_FAIL;
2759 goto error;
2760 }
2761
2762 kernel_wait_quiescent(kernel_tracer_fd);
2763
2764 /* Flush metadata after stopping (if exists) */
2765 if (ksession->metadata_stream_fd >= 0) {
2766 ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
2767 if (ret < 0) {
2768 ERR("Kernel metadata flush failed");
2769 }
2770 }
2771
2772 /* Flush all buffers after stopping */
2773 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
2774 ret = kernel_flush_buffer(kchan);
2775 if (ret < 0) {
2776 ERR("Kernel flush buffer error");
2777 }
2778 }
2779
2780 ksession->active = 0;
2781 DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
2782 session->id);
2783 }
2784
2785 if (usess && usess->active) {
2786 ret = ust_app_stop_trace_all(usess);
2787 if (ret < 0) {
2788 ret = LTTNG_ERR_UST_STOP_FAIL;
2789 goto error;
2790 }
2791 }
2792
2793 /* Flag inactive after a successful stop. */
2794 session->active = 0;
2795 ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
2796
2797 error:
2798 return ret;
2799 }
2800
2801 /*
2802 * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
2803 */
2804 int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
2805 struct lttng_uri *uris)
2806 {
2807 int ret, i;
2808 struct ltt_kernel_session *ksess = session->kernel_session;
2809 struct ltt_ust_session *usess = session->ust_session;
2810
2811 assert(session);
2812 assert(uris);
2813 assert(nb_uri > 0);
2814
2815 /* Can't set consumer URI if the session is active. */
2816 if (session->active) {
2817 ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
2818 goto error;
2819 }
2820
2821 /* Set the "global" consumer URIs */
2822 for (i = 0; i < nb_uri; i++) {
2823 ret = add_uri_to_consumer(session->consumer,
2824 &uris[i], 0, session->name);
2825 if (ret != LTTNG_OK) {
2826 goto error;
2827 }
2828 }
2829
2830 /* Set UST session URIs */
2831 if (session->ust_session) {
2832 for (i = 0; i < nb_uri; i++) {
2833 ret = add_uri_to_consumer(
2834 session->ust_session->consumer,
2835 &uris[i], LTTNG_DOMAIN_UST,
2836 session->name);
2837 if (ret != LTTNG_OK) {
2838 goto error;
2839 }
2840 }
2841 }
2842
2843 /* Set kernel session URIs */
2844 if (session->kernel_session) {
2845 for (i = 0; i < nb_uri; i++) {
2846 ret = add_uri_to_consumer(
2847 session->kernel_session->consumer,
2848 &uris[i], LTTNG_DOMAIN_KERNEL,
2849 session->name);
2850 if (ret != LTTNG_OK) {
2851 goto error;
2852 }
2853 }
2854 }
2855
2856 /*
2857 * Make sure to set the session in output mode after we set URI since a
2858 * session can be created without URL (thus flagged in no output mode).
2859 */
2860 session->output_traces = 1;
2861 if (ksess) {
2862 ksess->output_traces = 1;
2863 }
2864
2865 if (usess) {
2866 usess->output_traces = 1;
2867 }
2868
2869 /* All good! */
2870 ret = LTTNG_OK;
2871
2872 error:
2873 return ret;
2874 }
2875
2876 /*
2877 * Command LTTNG_CREATE_SESSION processed by the client thread.
2878 */
2879 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
2880 size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
2881 {
2882 int ret;
2883 struct ltt_session *session = NULL;
2884
2885 assert(name);
2886 assert(creds);
2887
2888 /* Check if the session already exists. */
2889 session_lock_list();
2890 session = session_find_by_name(name);
2891 session_unlock_list();
2892 if (session != NULL) {
2893 ret = LTTNG_ERR_EXIST_SESS;
2894 goto end;
2895 }
2896
2897 /* Create tracing session in the registry */
2898 ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
2899 LTTNG_SOCK_GET_GID_CRED(creds));
2900 if (ret != LTTNG_OK) {
2901 goto end;
2902 }
2903
2904 /* Get the newly created session pointer back. */
2905 session_lock_list();
2906 session = session_find_by_name(name);
2907 session_unlock_list();
2908 assert(session);
2909
2910 session->live_timer = live_timer;
2911 /* Create default consumer output for the session not yet created. */
2912 session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
2913 if (session->consumer == NULL) {
2914 ret = LTTNG_ERR_FATAL;
2915 goto end;
2916 }
2917
2918 if (uris) {
2919 ret = cmd_set_consumer_uri(session, nb_uri, uris);
2920 if (ret != LTTNG_OK) {
2921 goto end;
2922 }
2923 session->output_traces = 1;
2924 } else {
2925 session->output_traces = 0;
2926 DBG2("Session %s created with no output", session->name);
2927 }
2928
2929 session->consumer->enabled = 1;
2930
2931 ret = LTTNG_OK;
2932 end:
2933 if (session) {
2934 session_lock_list();
2935 session_put(session);
2936 session_unlock_list();
2937 }
2938 return ret;
2939 }
2940
2941 /*
2942 * Command LTTNG_CREATE_SESSION_SNAPSHOT processed by the client thread.
2943 */
2944 int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
2945 size_t nb_uri, lttng_sock_cred *creds)
2946 {
2947 int ret;
2948 struct ltt_session *session = NULL;
2949 struct snapshot_output *new_output = NULL;
2950
2951 assert(name);
2952 assert(creds);
2953
2954 /*
2955 * Create session in no output mode with URIs set to NULL. The uris we've
2956 * received are for a default snapshot output if one.
2957 */
2958 ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
2959 if (ret != LTTNG_OK) {
2960 goto end;
2961 }
2962
2963 /* Get the newly created session pointer back. This should NEVER fail. */
2964 session_lock_list();
2965 session = session_find_by_name(name);
2966 session_unlock_list();
2967 assert(session);
2968
2969 /* Flag session for snapshot mode. */
2970 session->snapshot_mode = 1;
2971
2972 /* Skip snapshot output creation if no URI is given. */
2973 if (nb_uri == 0) {
2974 /* Not an error. */
2975 goto end;
2976 }
2977
2978 new_output = snapshot_output_alloc();
2979 if (!new_output) {
2980 ret = LTTNG_ERR_NOMEM;
2981 goto error_snapshot_alloc;
2982 }
2983
2984 ret = snapshot_output_init_with_uri(DEFAULT_SNAPSHOT_MAX_SIZE, NULL,
2985 uris, nb_uri, session->consumer, new_output, &session->snapshot);
2986 if (ret < 0) {
2987 if (ret == -ENOMEM) {
2988 ret = LTTNG_ERR_NOMEM;
2989 } else {
2990 ret = LTTNG_ERR_INVALID;
2991 }
2992 goto error_snapshot;
2993 }
2994
2995 rcu_read_lock();
2996 snapshot_add_output(&session->snapshot, new_output);
2997 rcu_read_unlock();
2998
2999 ret = LTTNG_OK;
3000 goto end;
3001
3002 error_snapshot:
3003 snapshot_output_destroy(new_output);
3004 error_snapshot_alloc:
3005 end:
3006 if (session) {
3007 session_lock_list();
3008 session_put(session);
3009 session_unlock_list();
3010 }
3011 return ret;
3012 }
3013
3014 /*
3015 * Command LTTNG_DESTROY_SESSION processed by the client thread.
3016 *
3017 * Called with session lock held.
3018 */
3019 int cmd_destroy_session(struct ltt_session *session,
3020 struct notification_thread_handle *notification_thread_handle)
3021 {
3022 int ret;
3023
3024 /* Safety net */
3025 assert(session);
3026
3027 DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
3028
3029 if (session->rotation_schedule_timer_enabled) {
3030 if (timer_session_rotation_schedule_timer_stop(
3031 session)) {
3032 ERR("Failed to stop the \"rotation schedule\" timer of session %s",
3033 session->name);
3034 }
3035 }
3036
3037 if (session->rotate_size) {
3038 unsubscribe_session_consumed_size_rotation(session, notification_thread_handle);
3039 session->rotate_size = 0;
3040 }
3041
3042 if (session->current_archive_id != 0) {
3043 if (!session->rotated_after_last_stop) {
3044 ret = cmd_rotate_session(session, NULL);
3045 if (ret != LTTNG_OK) {
3046 ERR("Failed to perform an implicit rotation as part of the rotation: %s", lttng_strerror(-ret));
3047 }
3048 } else {
3049 /*
3050 * Rename the active chunk to ensure it has a name
3051 * of the form ts_begin-ts_end-id.
3052 *
3053 * Note that no trace data has been produced since
3054 * the last rotation; the directory should be
3055 * removed.
3056 */
3057 ret = rename_active_chunk(session);
3058 if (ret) {
3059 ERR("Failed to rename active chunk during the destruction of session \"%s\"",
3060 session->name);
3061 }
3062 }
3063 }
3064
3065 if (session->shm_path[0]) {
3066 /*
3067 * When a session is created with an explicit shm_path,
3068 * the consumer daemon will create its shared memory files
3069 * at that location and will *not* unlink them. This is normal
3070 * as the intention of that feature is to make it possible
3071 * to retrieve the content of those files should a crash occur.
3072 *
3073 * To ensure the content of those files can be used, the
3074 * sessiond daemon will replicate the content of the metadata
3075 * cache in a metadata file.
3076 *
3077 * On clean-up, it is expected that the consumer daemon will
3078 * unlink the shared memory files and that the session daemon
3079 * will unlink the metadata file. Then, the session's directory
3080 * in the shm path can be removed.
3081 *
3082 * Unfortunately, a flaw in the design of the sessiond's and
3083 * consumerd's tear down of channels makes it impossible to
3084 * determine when the sessiond _and_ the consumerd have both
3085 * destroyed their representation of a channel. For one, the
3086 * unlinking, close, and rmdir happen in deferred 'call_rcu'
3087 * callbacks in both daemons.
3088 *
3089 * However, it is also impossible for the sessiond to know when
3090 * the consumer daemon is done destroying its channel(s) since
3091 * it occurs as a reaction to the closing of the channel's file
3092 * descriptor. There is no resulting communication initiated
3093 * from the consumerd to the sessiond to confirm that the
3094 * operation is completed (and was successful).
3095 *
3096 * Until this is all fixed, the session daemon checks for the
3097 * removal of the session's shm path which makes it possible
3098 * to safely advertise a session as having been destroyed.
3099 *
3100 * Prior to this fix, it was not possible to reliably save
3101 * a session making use of the --shm-path option, destroy it,
3102 * and load it again. This is because the creation of the
3103 * session would fail upon seeing the session's shm path
3104 * already in existence.
3105 *
3106 * Note that none of the error paths in the check for the
3107 * directory's existence return an error. This is normal
3108 * as there isn't much that can be done. The session will
3109 * be destroyed properly, except that we can't offer the
3110 * guarantee that the same session can be re-created.
3111 */
3112 current_completion_handler = &destroy_completion_handler.handler;
3113 ret = lttng_strncpy(destroy_completion_handler.shm_path,
3114 session->shm_path,
3115 sizeof(destroy_completion_handler.shm_path));
3116 assert(!ret);
3117 }
3118
3119 /*
3120 * The session is destroyed. However, note that the command context
3121 * still holds a reference to the session, thus delaying its destruction
3122 * _at least_ up to the point when that reference is released.
3123 */
3124 session_destroy(session);
3125 ret = LTTNG_OK;
3126
3127 return ret;
3128 }
3129
3130 /*
3131 * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
3132 */
3133 int cmd_register_consumer(struct ltt_session *session,
3134 enum lttng_domain_type domain, const char *sock_path,
3135 struct consumer_data *cdata)
3136 {
3137 int ret, sock;
3138 struct consumer_socket *socket = NULL;
3139
3140 assert(session);
3141 assert(cdata);
3142 assert(sock_path);
3143
3144 switch (domain) {
3145 case LTTNG_DOMAIN_KERNEL:
3146 {
3147 struct ltt_kernel_session *ksess = session->kernel_session;
3148
3149 assert(ksess);
3150
3151 /* Can't register a consumer if there is already one */
3152 if (ksess->consumer_fds_sent != 0) {
3153 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
3154 goto error;
3155 }
3156
3157 sock = lttcomm_connect_unix_sock(sock_path);
3158 if (sock < 0) {
3159 ret = LTTNG_ERR_CONNECT_FAIL;
3160 goto error;
3161 }
3162 cdata->cmd_sock = sock;
3163
3164 socket = consumer_allocate_socket(&cdata->cmd_sock);
3165 if (socket == NULL) {
3166 ret = close(sock);
3167 if (ret < 0) {
3168 PERROR("close register consumer");
3169 }
3170 cdata->cmd_sock = -1;
3171 ret = LTTNG_ERR_FATAL;
3172 goto error;
3173 }
3174
3175 socket->lock = zmalloc(sizeof(pthread_mutex_t));
3176 if (socket->lock == NULL) {
3177 PERROR("zmalloc pthread mutex");
3178 ret = LTTNG_ERR_FATAL;
3179 goto error;
3180 }
3181 pthread_mutex_init(socket->lock, NULL);
3182 socket->registered = 1;
3183
3184 rcu_read_lock();
3185 consumer_add_socket(socket, ksess->consumer);
3186 rcu_read_unlock();
3187
3188 pthread_mutex_lock(&cdata->pid_mutex);
3189 cdata->pid = -1;
3190 pthread_mutex_unlock(&cdata->pid_mutex);
3191
3192 break;
3193 }
3194 default:
3195 /* TODO: Userspace tracing */
3196 ret = LTTNG_ERR_UND;
3197 goto error;
3198 }
3199
3200 return LTTNG_OK;
3201
3202 error:
3203 if (socket) {
3204 consumer_destroy_socket(socket);
3205 }
3206 return ret;
3207 }
3208
3209 /*
3210 * Command LTTNG_LIST_DOMAINS processed by the client thread.
3211 */
3212 ssize_t cmd_list_domains(struct ltt_session *session,
3213 struct lttng_domain **domains)
3214 {
3215 int ret, index = 0;
3216 ssize_t nb_dom = 0;
3217 struct agent *agt;
3218 struct lttng_ht_iter iter;
3219
3220 if (session->kernel_session != NULL) {
3221 DBG3("Listing domains found kernel domain");
3222 nb_dom++;
3223 }
3224
3225 if (session->ust_session != NULL) {
3226 DBG3("Listing domains found UST global domain");
3227 nb_dom++;
3228
3229 rcu_read_lock();
3230 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3231 agt, node.node) {
3232 if (agt->being_used) {
3233 nb_dom++;
3234 }
3235 }
3236 rcu_read_unlock();
3237 }
3238
3239 if (!nb_dom) {
3240 goto end;
3241 }
3242
3243 *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
3244 if (*domains == NULL) {
3245 ret = LTTNG_ERR_FATAL;
3246 goto error;
3247 }
3248
3249 if (session->kernel_session != NULL) {
3250 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
3251
3252 /* Kernel session buffer type is always GLOBAL */
3253 (*domains)[index].buf_type = LTTNG_BUFFER_GLOBAL;
3254
3255 index++;
3256 }
3257
3258 if (session->ust_session != NULL) {
3259 (*domains)[index].type = LTTNG_DOMAIN_UST;
3260 (*domains)[index].buf_type = session->ust_session->buffer_type;
3261 index++;
3262
3263 rcu_read_lock();
3264 cds_lfht_for_each_entry(session->ust_session->agents->ht, &iter.iter,
3265 agt, node.node) {
3266 if (agt->being_used) {
3267 (*domains)[index].type = agt->domain;
3268 (*domains)[index].buf_type = session->ust_session->buffer_type;
3269 index++;
3270 }
3271 }
3272 rcu_read_unlock();
3273 }
3274 end:
3275 return nb_dom;
3276
3277 error:
3278 /* Return negative value to differentiate return code */
3279 return -ret;
3280 }
3281
3282
3283 /*
3284 * Command LTTNG_LIST_CHANNELS processed by the client thread.
3285 */
3286 ssize_t cmd_list_channels(enum lttng_domain_type domain,
3287 struct ltt_session *session, struct lttng_channel **channels)
3288 {
3289 ssize_t nb_chan = 0, payload_size = 0, ret;
3290
3291 switch (domain) {
3292 case LTTNG_DOMAIN_KERNEL:
3293 if (session->kernel_session != NULL) {
3294 nb_chan = session->kernel_session->channel_count;
3295 }
3296 DBG3("Number of kernel channels %zd", nb_chan);
3297 if (nb_chan <= 0) {
3298 ret = -LTTNG_ERR_KERN_CHAN_NOT_FOUND;
3299 goto end;
3300 }
3301 break;
3302 case LTTNG_DOMAIN_UST:
3303 if (session->ust_session != NULL) {
3304 rcu_read_lock();
3305 nb_chan = lttng_ht_get_count(
3306 session->ust_session->domain_global.channels);
3307 rcu_read_unlock();
3308 }
3309 DBG3("Number of UST global channels %zd", nb_chan);
3310 if (nb_chan < 0) {
3311 ret = -LTTNG_ERR_UST_CHAN_NOT_FOUND;
3312 goto end;
3313 }
3314 break;
3315 default:
3316 ret = -LTTNG_ERR_UND;
3317 goto end;
3318 }
3319
3320 if (nb_chan > 0) {
3321 const size_t channel_size = sizeof(struct lttng_channel) +
3322 sizeof(struct lttng_channel_extended);
3323 struct lttng_channel_extended *channel_exts;
3324
3325 payload_size = nb_chan * channel_size;
3326 *channels = zmalloc(payload_size);
3327 if (*channels == NULL) {
3328 ret = -LTTNG_ERR_FATAL;
3329 goto end;
3330 }
3331
3332 channel_exts = ((void *) *channels) +
3333 (nb_chan * sizeof(struct lttng_channel));
3334 ret = list_lttng_channels(domain, session, *channels, channel_exts);
3335 if (ret != LTTNG_OK) {
3336 free(*channels);
3337 *channels = NULL;
3338 goto end;
3339 }
3340 } else {
3341 *channels = NULL;
3342 }
3343
3344 ret = payload_size;
3345 end:
3346 return ret;
3347 }
3348
3349 /*
3350 * Command LTTNG_LIST_EVENTS processed by the client thread.
3351 */
3352 ssize_t cmd_list_events(enum lttng_domain_type domain,
3353 struct ltt_session *session, char *channel_name,
3354 struct lttng_event **events, size_t *total_size)
3355 {
3356 int ret = 0;
3357 ssize_t nb_event = 0;
3358
3359 switch (domain) {
3360 case LTTNG_DOMAIN_KERNEL:
3361 if (session->kernel_session != NULL) {
3362 nb_event = list_lttng_kernel_events(channel_name,
3363 session->kernel_session, events,
3364 total_size);
3365 }
3366 break;
3367 case LTTNG_DOMAIN_UST:
3368 {
3369 if (session->ust_session != NULL) {
3370 nb_event = list_lttng_ust_global_events(channel_name,
3371 &session->ust_session->domain_global, events,
3372 total_size);
3373 }
3374 break;
3375 }
3376 case LTTNG_DOMAIN_LOG4J:
3377 case LTTNG_DOMAIN_JUL:
3378 case LTTNG_DOMAIN_PYTHON:
3379 if (session->ust_session) {
3380 struct lttng_ht_iter iter;
3381 struct agent *agt;
3382
3383 rcu_read_lock();
3384 cds_lfht_for_each_entry(session->ust_session->agents->ht,
3385 &iter.iter, agt, node.node) {
3386 if (agt->domain == domain) {
3387 nb_event = list_lttng_agent_events(
3388 agt, events,
3389 total_size);
3390 break;
3391 }
3392 }
3393 rcu_read_unlock();
3394 }
3395 break;
3396 default:
3397 ret = LTTNG_ERR_UND;
3398 goto error;
3399 }
3400
3401 return nb_event;
3402
3403 error:
3404 /* Return negative value to differentiate return code */
3405 return -ret;
3406 }
3407
3408 /*
3409 * Using the session list, filled a lttng_session array to send back to the
3410 * client for session listing.
3411 *
3412 * The session list lock MUST be acquired before calling this function. Use
3413 * session_lock_list() and session_unlock_list().
3414 */
3415 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
3416 gid_t gid)
3417 {
3418 int ret;
3419 unsigned int i = 0;
3420 struct ltt_session *session;
3421 struct ltt_session_list *list = session_get_list();
3422
3423 DBG("Getting all available session for UID %d GID %d",
3424 uid, gid);
3425 /*
3426 * Iterate over session list and append data after the control struct in
3427 * the buffer.
3428 */
3429 cds_list_for_each_entry(session, &list->head, list) {
3430 if (!session_get(session)) {
3431 continue;
3432 }
3433 /*
3434 * Only list the sessions the user can control.
3435 */
3436 if (!session_access_ok(session, uid, gid) ||
3437 session->destroyed) {
3438 session_put(session);
3439 continue;
3440 }
3441
3442 struct ltt_kernel_session *ksess = session->kernel_session;
3443 struct ltt_ust_session *usess = session->ust_session;
3444
3445 if (session->consumer->type == CONSUMER_DST_NET ||
3446 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
3447 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
3448 ret = build_network_session_path(sessions[i].path,
3449 sizeof(sessions[i].path), session);
3450 } else {
3451 ret = snprintf(sessions[i].path, sizeof(sessions[i].path), "%s",
3452 session->consumer->dst.session_root_path);
3453 }
3454 if (ret < 0) {
3455 PERROR("snprintf session path");
3456 session_put(session);
3457 continue;
3458 }
3459
3460 strncpy(sessions[i].name, session->name, NAME_MAX);
3461 sessions[i].name[NAME_MAX - 1] = '\0';
3462 sessions[i].enabled = session->active;
3463 sessions[i].snapshot_mode = session->snapshot_mode;
3464 sessions[i].live_timer_interval = session->live_timer;
3465 i++;
3466 session_put(session);
3467 }
3468 }
3469
3470 /*
3471 * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
3472 * ready for trace analysis (or any kind of reader) or else 1 for pending data.
3473 */
3474 int cmd_data_pending(struct ltt_session *session)
3475 {
3476 int ret;
3477 struct ltt_kernel_session *ksess = session->kernel_session;
3478 struct ltt_ust_session *usess = session->ust_session;
3479
3480 assert(session);
3481
3482 DBG("Data pending for session %s", session->name);
3483
3484 /* Session MUST be stopped to ask for data availability. */
3485 if (session->active) {
3486 ret = LTTNG_ERR_SESSION_STARTED;
3487 goto error;
3488 } else {
3489 /*
3490 * If stopped, just make sure we've started before else the above call
3491 * will always send that there is data pending.
3492 *
3493 * The consumer assumes that when the data pending command is received,
3494 * the trace has been started before or else no output data is written
3495 * by the streams which is a condition for data pending. So, this is
3496 * *VERY* important that we don't ask the consumer before a start
3497 * trace.
3498 */
3499 if (!session->has_been_started) {
3500 ret = 0;
3501 goto error;
3502 }
3503 }
3504
3505 /* A rotation is still pending, we have to wait. */
3506 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
3507 DBG("Rotate still pending for session %s", session->name);
3508 ret = 1;
3509 goto error;
3510 }
3511
3512 if (ksess && ksess->consumer) {
3513 ret = consumer_is_data_pending(ksess->id, ksess->consumer);
3514 if (ret == 1) {
3515 /* Data is still being extracted for the kernel. */
3516 goto error;
3517 }
3518 }
3519
3520 if (usess && usess->consumer) {
3521 ret = consumer_is_data_pending(usess->id, usess->consumer);
3522 if (ret == 1) {
3523 /* Data is still being extracted for the kernel. */
3524 goto error;
3525 }
3526 }
3527
3528 /* Data is ready to be read by a viewer */
3529 ret = 0;
3530
3531 error:
3532 return ret;
3533 }
3534
3535 /*
3536 * Command LTTNG_SNAPSHOT_ADD_OUTPUT from the lttng ctl library.
3537 *
3538 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3539 */
3540 int cmd_snapshot_add_output(struct ltt_session *session,
3541 struct lttng_snapshot_output *output, uint32_t *id)
3542 {
3543 int ret;
3544 struct snapshot_output *new_output;
3545
3546 assert(session);
3547 assert(output);
3548
3549 DBG("Cmd snapshot add output for session %s", session->name);
3550
3551 /*
3552 * Can't create an output if the session is not set in no-output mode.
3553 */
3554 if (session->output_traces) {
3555 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3556 goto error;
3557 }
3558
3559 if (session->has_non_mmap_channel) {
3560 ret = LTTNG_ERR_SNAPSHOT_UNSUPPORTED;
3561 goto error;
3562 }
3563
3564 /* Only one output is allowed until we have the "tee" feature. */
3565 if (session->snapshot.nb_output == 1) {
3566 ret = LTTNG_ERR_SNAPSHOT_OUTPUT_EXIST;
3567 goto error;
3568 }
3569
3570 new_output = snapshot_output_alloc();
3571 if (!new_output) {
3572 ret = LTTNG_ERR_NOMEM;
3573 goto error;
3574 }
3575
3576 ret = snapshot_output_init(output->max_size, output->name,
3577 output->ctrl_url, output->data_url, session->consumer, new_output,
3578 &session->snapshot);
3579 if (ret < 0) {
3580 if (ret == -ENOMEM) {
3581 ret = LTTNG_ERR_NOMEM;
3582 } else {
3583 ret = LTTNG_ERR_INVALID;
3584 }
3585 goto free_error;
3586 }
3587
3588 rcu_read_lock();
3589 snapshot_add_output(&session->snapshot, new_output);
3590 if (id) {
3591 *id = new_output->id;
3592 }
3593 rcu_read_unlock();
3594
3595 return LTTNG_OK;
3596
3597 free_error:
3598 snapshot_output_destroy(new_output);
3599 error:
3600 return ret;
3601 }
3602
3603 /*
3604 * Command LTTNG_SNAPSHOT_DEL_OUTPUT from lib lttng ctl.
3605 *
3606 * Return LTTNG_OK on success or else a LTTNG_ERR code.
3607 */
3608 int cmd_snapshot_del_output(struct ltt_session *session,
3609 struct lttng_snapshot_output *output)
3610 {
3611 int ret;
3612 struct snapshot_output *sout = NULL;
3613
3614 assert(session);
3615 assert(output);
3616
3617 rcu_read_lock();
3618
3619 /*
3620 * Permission denied to create an output if the session is not
3621 * set in no output mode.
3622 */
3623 if (session->output_traces) {
3624 ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3625 goto error;
3626 }
3627
3628 if (output->id) {
3629 DBG("Cmd snapshot del output id %" PRIu32 " for session %s", output->id,
3630 session->name);
3631 sout = snapshot_find_output_by_id(output->id, &session->snapshot);
3632 } else if (*output->name != '\0') {
3633 DBG("Cmd snapshot del output name %s for session %s", output->name,
3634 session->name);
3635 sout = snapshot_find_output_by_name(output->name, &session->snapshot);
3636 }
3637 if (!sout) {
3638 ret = LTTNG_ERR_INVALID;
3639 goto error;
3640 }
3641
3642 snapshot_delete_output(&session->snapshot, sout);
3643 snapshot_output_destroy(sout);
3644 ret = LTTNG_OK;
3645
3646 error:
3647 rcu_read_unlock();
3648 return ret;
3649 }
3650
3651 /*
3652 * Command LTTNG_SNAPSHOT_LIST_OUTPUT from lib lttng ctl.
3653 *
3654 * If no output is available, outputs is untouched and 0 is returned.
3655 *
3656 * Return the size of the newly allocated outputs or a negative LTTNG_ERR code.
3657 */
3658 ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
3659 struct lttng_snapshot_output **outputs)
3660 {
3661 int ret, idx = 0;
3662 struct lttng_snapshot_output *list = NULL;
3663 struct lttng_ht_iter iter;
3664 struct snapshot_output *output;
3665
3666 assert(session);
3667 assert(outputs);
3668
3669 DBG("Cmd snapshot list outputs for session %s", session->name);
3670
3671 /*
3672 * Permission denied to create an output if the session is not
3673 * set in no output mode.
3674 */
3675 if (session->output_traces) {
3676 ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
3677 goto end;
3678 }
3679
3680 if (session->snapshot.nb_output == 0) {
3681 ret = 0;
3682 goto end;
3683 }
3684
3685 list = zmalloc(session->snapshot.nb_output * sizeof(*list));
3686 if (!list) {
3687 ret = -LTTNG_ERR_NOMEM;
3688 goto end;
3689 }
3690
3691 /* Copy list from session to the new list object. */
3692 rcu_read_lock();
3693 cds_lfht_for_each_entry(session->snapshot.output_ht->ht, &iter.iter,
3694 output, node.node) {
3695 assert(output->consumer);
3696 list[idx].id = output->id;
3697 list[idx].max_size = output->max_size;
3698 if (lttng_strncpy(list[idx].name, output->name,
3699 sizeof(list[idx].name))) {
3700 ret = -LTTNG_ERR_INVALID;
3701 goto error;
3702 }
3703 if (output->consumer->type == CONSUMER_DST_LOCAL) {
3704 if (lttng_strncpy(list[idx].ctrl_url,
3705 output->consumer->dst.session_root_path,
3706 sizeof(list[idx].ctrl_url))) {
3707 ret = -LTTNG_ERR_INVALID;
3708 goto error;
3709 }
3710 } else {
3711 /* Control URI. */
3712 ret = uri_to_str_url(&output->consumer->dst.net.control,
3713 list[idx].ctrl_url, sizeof(list[idx].ctrl_url));
3714 if (ret < 0) {
3715 ret = -LTTNG_ERR_NOMEM;
3716 goto error;
3717 }
3718
3719 /* Data URI. */
3720 ret = uri_to_str_url(&output->consumer->dst.net.data,
3721 list[idx].data_url, sizeof(list[idx].data_url));
3722 if (ret < 0) {
3723 ret = -LTTNG_ERR_NOMEM;
3724 goto error;
3725 }
3726 }
3727 idx++;
3728 }
3729
3730 *outputs = list;
3731 list = NULL;
3732 ret = session->snapshot.nb_output;
3733 error:
3734 rcu_read_unlock();
3735 free(list);
3736 end:
3737 return ret;
3738 }
3739
3740 /*
3741 * Check if we can regenerate the metadata for this session.
3742 * Only kernel, UST per-uid and non-live sessions are supported.
3743 *
3744 * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
3745 */
3746 static
3747 int check_regenerate_metadata_support(struct ltt_session *session)
3748 {
3749 int ret;
3750
3751 assert(session);
3752
3753 if (session->live_timer != 0) {
3754 ret = LTTNG_ERR_LIVE_SESSION;
3755 goto end;
3756 }
3757 if (!session->active) {
3758 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3759 goto end;
3760 }
3761 if (session->ust_session) {
3762 switch (session->ust_session->buffer_type) {
3763 case LTTNG_BUFFER_PER_UID:
3764 break;
3765 case LTTNG_BUFFER_PER_PID:
3766 ret = LTTNG_ERR_PER_PID_SESSION;
3767 goto end;
3768 default:
3769 assert(0);
3770 ret = LTTNG_ERR_UNK;
3771 goto end;
3772 }
3773 }
3774 if (session->consumer->type == CONSUMER_DST_NET &&
3775 session->consumer->relay_minor_version < 8) {
3776 ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
3777 goto end;
3778 }
3779 ret = 0;
3780
3781 end:
3782 return ret;
3783 }
3784
3785 static
3786 int clear_metadata_file(int fd)
3787 {
3788 int ret;
3789 off_t lseek_ret;
3790
3791 lseek_ret = lseek(fd, 0, SEEK_SET);
3792 if (lseek_ret < 0) {
3793 PERROR("lseek");
3794 ret = -1;
3795 goto end;
3796 }
3797
3798 ret = ftruncate(fd, 0);
3799 if (ret < 0) {
3800 PERROR("ftruncate");
3801 goto end;
3802 }
3803
3804 end:
3805 return ret;
3806 }
3807
3808 static
3809 int ust_regenerate_metadata(struct ltt_ust_session *usess)
3810 {
3811 int ret = 0;
3812 struct buffer_reg_uid *uid_reg = NULL;
3813 struct buffer_reg_session *session_reg = NULL;
3814
3815 rcu_read_lock();
3816 cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
3817 struct ust_registry_session *registry;
3818 struct ust_registry_channel *chan;
3819 struct lttng_ht_iter iter_chan;
3820
3821 session_reg = uid_reg->registry;
3822 registry = session_reg->reg.ust;
3823
3824 pthread_mutex_lock(&registry->lock);
3825 registry->metadata_len_sent = 0;
3826 memset(registry->metadata, 0, registry->metadata_alloc_len);
3827 registry->metadata_len = 0;
3828 registry->metadata_version++;
3829 if (registry->metadata_fd > 0) {
3830 /* Clear the metadata file's content. */
3831 ret = clear_metadata_file(registry->metadata_fd);
3832 if (ret) {
3833 pthread_mutex_unlock(&registry->lock);
3834 goto end;
3835 }
3836 }
3837
3838 ret = ust_metadata_session_statedump(registry, NULL,
3839 registry->major, registry->minor);
3840 if (ret) {
3841 pthread_mutex_unlock(&registry->lock);
3842 ERR("Failed to generate session metadata (err = %d)",
3843 ret);
3844 goto end;
3845 }
3846 cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
3847 chan, node.node) {
3848 struct ust_registry_event *event;
3849 struct lttng_ht_iter iter_event;
3850
3851 ret = ust_metadata_channel_statedump(registry, chan);
3852 if (ret) {
3853 pthread_mutex_unlock(&registry->lock);
3854 ERR("Failed to generate channel metadata "
3855 "(err = %d)", ret);
3856 goto end;
3857 }
3858 cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
3859 event, node.node) {
3860 ret = ust_metadata_event_statedump(registry,
3861 chan, event);
3862 if (ret) {
3863 pthread_mutex_unlock(&registry->lock);
3864 ERR("Failed to generate event metadata "
3865 "(err = %d)", ret);
3866 goto end;
3867 }
3868 }
3869 }
3870 pthread_mutex_unlock(&registry->lock);
3871 }
3872
3873 end:
3874 rcu_read_unlock();
3875 return ret;
3876 }
3877
3878 /*
3879 * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
3880 *
3881 * Ask the consumer to truncate the existing metadata file(s) and
3882 * then regenerate the metadata. Live and per-pid sessions are not
3883 * supported and return an error.
3884 *
3885 * Return 0 on success or else a LTTNG_ERR code.
3886 */
3887 int cmd_regenerate_metadata(struct ltt_session *session)
3888 {
3889 int ret;
3890
3891 assert(session);
3892
3893 ret = check_regenerate_metadata_support(session);
3894 if (ret) {
3895 goto end;
3896 }
3897
3898 if (session->kernel_session) {
3899 ret = kernctl_session_regenerate_metadata(
3900 session->kernel_session->fd);
3901 if (ret < 0) {
3902 ERR("Failed to regenerate the kernel metadata");
3903 goto end;
3904 }
3905 }
3906
3907 if (session->ust_session) {
3908 ret = ust_regenerate_metadata(session->ust_session);
3909 if (ret < 0) {
3910 ERR("Failed to regenerate the UST metadata");
3911 goto end;
3912 }
3913 }
3914 DBG("Cmd metadata regenerate for session %s", session->name);
3915 ret = LTTNG_OK;
3916
3917 end:
3918 return ret;
3919 }
3920
3921 /*
3922 * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
3923 *
3924 * Ask the tracer to regenerate a new statedump.
3925 *
3926 * Return 0 on success or else a LTTNG_ERR code.
3927 */
3928 int cmd_regenerate_statedump(struct ltt_session *session)
3929 {
3930 int ret;
3931
3932 assert(session);
3933
3934 if (!session->active) {
3935 ret = LTTNG_ERR_SESSION_NOT_STARTED;
3936 goto end;
3937 }
3938
3939 if (session->kernel_session) {
3940 ret = kernctl_session_regenerate_statedump(
3941 session->kernel_session->fd);
3942 /*
3943 * Currently, the statedump in kernel can only fail if out
3944 * of memory.
3945 */
3946 if (ret < 0) {
3947 if (ret == -ENOMEM) {
3948 ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
3949 } else {
3950 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
3951 }
3952 ERR("Failed to regenerate the kernel statedump");
3953 goto end;
3954 }
3955 }
3956
3957 if (session->ust_session) {
3958 ret = ust_app_regenerate_statedump_all(session->ust_session);
3959 /*
3960 * Currently, the statedump in UST always returns 0.
3961 */
3962 if (ret < 0) {
3963 ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
3964 ERR("Failed to regenerate the UST statedump");
3965 goto end;
3966 }
3967 }
3968 DBG("Cmd regenerate statedump for session %s", session->name);
3969 ret = LTTNG_OK;
3970
3971 end:
3972 return ret;
3973 }
3974
3975 int cmd_register_trigger(struct command_ctx *cmd_ctx, int sock,
3976 struct notification_thread_handle *notification_thread)
3977 {
3978 int ret;
3979 size_t trigger_len;
3980 ssize_t sock_recv_len;
3981 struct lttng_trigger *trigger = NULL;
3982 struct lttng_buffer_view view;
3983 struct lttng_dynamic_buffer trigger_buffer;
3984
3985 lttng_dynamic_buffer_init(&trigger_buffer);
3986 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
3987 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
3988 if (ret) {
3989 ret = LTTNG_ERR_NOMEM;
3990 goto end;
3991 }
3992
3993 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
3994 trigger_len);
3995 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
3996 ERR("Failed to receive \"register trigger\" command payload");
3997 /* TODO: should this be a new error enum ? */
3998 ret = LTTNG_ERR_INVALID_TRIGGER;
3999 goto end;
4000 }
4001
4002 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4003 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4004 trigger_len) {
4005 ERR("Invalid trigger payload received in \"register trigger\" command");
4006 ret = LTTNG_ERR_INVALID_TRIGGER;
4007 goto end;
4008 }
4009
4010 ret = notification_thread_command_register_trigger(notification_thread,
4011 trigger);
4012 /* Ownership of trigger was transferred. */
4013 trigger = NULL;
4014 end:
4015 lttng_trigger_destroy(trigger);
4016 lttng_dynamic_buffer_reset(&trigger_buffer);
4017 return ret;
4018 }
4019
4020 int cmd_unregister_trigger(struct command_ctx *cmd_ctx, int sock,
4021 struct notification_thread_handle *notification_thread)
4022 {
4023 int ret;
4024 size_t trigger_len;
4025 ssize_t sock_recv_len;
4026 struct lttng_trigger *trigger = NULL;
4027 struct lttng_buffer_view view;
4028 struct lttng_dynamic_buffer trigger_buffer;
4029
4030 lttng_dynamic_buffer_init(&trigger_buffer);
4031 trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
4032 ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
4033 if (ret) {
4034 ret = LTTNG_ERR_NOMEM;
4035 goto end;
4036 }
4037
4038 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
4039 trigger_len);
4040 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
4041 ERR("Failed to receive \"unregister trigger\" command payload");
4042 /* TODO: should this be a new error enum ? */
4043 ret = LTTNG_ERR_INVALID_TRIGGER;
4044 goto end;
4045 }
4046
4047 view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
4048 if (lttng_trigger_create_from_buffer(&view, &trigger) !=
4049 trigger_len) {
4050 ERR("Invalid trigger payload received in \"unregister trigger\" command");
4051 ret = LTTNG_ERR_INVALID_TRIGGER;
4052 goto end;
4053 }
4054
4055 ret = notification_thread_command_unregister_trigger(notification_thread,
4056 trigger);
4057 end:
4058 lttng_trigger_destroy(trigger);
4059 lttng_dynamic_buffer_reset(&trigger_buffer);
4060 return ret;
4061 }
4062
4063 /*
4064 * Send relayd sockets from snapshot output to consumer. Ignore request if the
4065 * snapshot output is *not* set with a remote destination.
4066 *
4067 * Return LTTNG_OK on success or a LTTNG_ERR code.
4068 */
4069 static enum lttng_error_code set_relayd_for_snapshot(
4070 struct consumer_output *consumer,
4071 struct snapshot_output *snap_output,
4072 struct ltt_session *session)
4073 {
4074 enum lttng_error_code status = LTTNG_OK;
4075 struct lttng_ht_iter iter;
4076 struct consumer_socket *socket;
4077
4078 assert(consumer);
4079 assert(snap_output);
4080 assert(session);
4081
4082 DBG2("Set relayd object from snapshot output");
4083
4084 /* Ignore if snapshot consumer output is not network. */
4085 if (snap_output->consumer->type != CONSUMER_DST_NET) {
4086 goto error;
4087 }
4088
4089 /*
4090 * For each consumer socket, create and send the relayd object of the
4091 * snapshot output.
4092 */
4093 rcu_read_lock();
4094 cds_lfht_for_each_entry(snap_output->consumer->socks->ht, &iter.iter,
4095 socket, node.node) {
4096 pthread_mutex_lock(socket->lock);
4097 status = send_consumer_relayd_sockets(0, session->id,
4098 snap_output->consumer, socket,
4099 session->name, session->hostname,
4100 session->live_timer);
4101 pthread_mutex_unlock(socket->lock);
4102 if (status != LTTNG_OK) {
4103 rcu_read_unlock();
4104 goto error;
4105 }
4106 }
4107 rcu_read_unlock();
4108
4109 error:
4110 return status;
4111 }
4112
4113 /*
4114 * Record a kernel snapshot.
4115 *
4116 * Return LTTNG_OK on success or a LTTNG_ERR code.
4117 */
4118 static enum lttng_error_code record_kernel_snapshot(struct ltt_kernel_session *ksess,
4119 struct snapshot_output *output, struct ltt_session *session,
4120 int wait, uint64_t nb_packets_per_stream)
4121 {
4122 int ret;
4123 enum lttng_error_code status;
4124
4125 assert(ksess);
4126 assert(output);
4127 assert(session);
4128
4129 /*
4130 * Copy kernel session sockets so we can communicate with the right
4131 * consumer for the snapshot record command.
4132 */
4133 ret = consumer_copy_sockets(output->consumer, ksess->consumer);
4134 if (ret < 0) {
4135 status = LTTNG_ERR_NOMEM;
4136 goto error;
4137 }
4138
4139 status = set_relayd_for_snapshot(ksess->consumer, output, session);
4140 if (status != LTTNG_OK) {
4141 goto error_snapshot;
4142 }
4143
4144 status = kernel_snapshot_record(ksess, output, wait, nb_packets_per_stream);
4145 if (status != LTTNG_OK) {
4146 goto error_snapshot;
4147 }
4148
4149 goto end;
4150
4151 error_snapshot:
4152 /* Clean up copied sockets so this output can use some other later on. */
4153 consumer_destroy_output_sockets(output->consumer);
4154 error:
4155 end:
4156 return status;
4157 }
4158
4159 /*
4160 * Record a UST snapshot.
4161 *
4162 * Returns LTTNG_OK on success or a LTTNG_ERR error code.
4163 */
4164 static enum lttng_error_code record_ust_snapshot(struct ltt_ust_session *usess,
4165 struct snapshot_output *output, struct ltt_session *session,
4166 int wait, uint64_t nb_packets_per_stream)
4167 {
4168 int ret;
4169 enum lttng_error_code status;
4170
4171 assert(usess);
4172 assert(output);
4173 assert(session);
4174
4175 /*
4176 * Copy UST session sockets so we can communicate with the right
4177 * consumer for the snapshot record command.
4178 */
4179 ret = consumer_copy_sockets(output->consumer, usess->consumer);
4180 if (ret < 0) {
4181 status = LTTNG_ERR_NOMEM;
4182 goto error;
4183 }
4184
4185 status = set_relayd_for_snapshot(usess->consumer, output, session);
4186 if (status != LTTNG_OK) {
4187 goto error_snapshot;
4188 }
4189
4190 status = ust_app_snapshot_record(usess, output, wait, nb_packets_per_stream);
4191 if (status != LTTNG_OK) {
4192 goto error_snapshot;
4193 }
4194
4195 goto end;
4196
4197 error_snapshot:
4198 /* Clean up copied sockets so this output can use some other later on. */
4199 consumer_destroy_output_sockets(output->consumer);
4200 error:
4201 end:
4202 return status;
4203 }
4204
4205 static
4206 uint64_t get_session_size_one_more_packet_per_stream(struct ltt_session *session,
4207 uint64_t cur_nr_packets)
4208 {
4209 uint64_t tot_size = 0;
4210
4211 if (session->kernel_session) {
4212 struct ltt_kernel_channel *chan;
4213 struct ltt_kernel_session *ksess = session->kernel_session;
4214
4215 cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
4216 if (cur_nr_packets >= chan->channel->attr.num_subbuf) {
4217 /*
4218 * Don't take channel into account if we
4219 * already grab all its packets.
4220 */
4221 continue;
4222 }
4223 tot_size += chan->channel->attr.subbuf_size
4224 * chan->stream_count;
4225 }
4226 }
4227
4228 if (session->ust_session) {
4229 struct ltt_ust_session *usess = session->ust_session;
4230
4231 tot_size += ust_app_get_size_one_more_packet_per_stream(usess,
4232 cur_nr_packets);
4233 }
4234
4235 return tot_size;
4236 }
4237
4238 /*
4239 * Calculate the number of packets we can grab from each stream that
4240 * fits within the overall snapshot max size.
4241 *
4242 * Returns -1 on error, 0 means infinite number of packets, else > 0 is
4243 * the number of packets per stream.
4244 *
4245 * TODO: this approach is not perfect: we consider the worse case
4246 * (packet filling the sub-buffers) as an upper bound, but we could do
4247 * better if we do this calculation while we actually grab the packet
4248 * content: we would know how much padding we don't actually store into
4249 * the file.
4250 *
4251 * This algorithm is currently bounded by the number of packets per
4252 * stream.
4253 *
4254 * Since we call this algorithm before actually grabbing the data, it's
4255 * an approximation: for instance, applications could appear/disappear
4256 * in between this call and actually grabbing data.
4257 */
4258 static
4259 int64_t get_session_nb_packets_per_stream(struct ltt_session *session, uint64_t max_size)
4260 {
4261 int64_t size_left;
4262 uint64_t cur_nb_packets = 0;
4263
4264 if (!max_size) {
4265 return 0; /* Infinite */
4266 }
4267
4268 size_left = max_size;
4269 for (;;) {
4270 uint64_t one_more_packet_tot_size;
4271
4272 one_more_packet_tot_size = get_session_size_one_more_packet_per_stream(session,
4273 cur_nb_packets);
4274 if (!one_more_packet_tot_size) {
4275 /* We are already grabbing all packets. */
4276 break;
4277 }
4278 size_left -= one_more_packet_tot_size;
4279 if (size_left < 0) {
4280 break;
4281 }
4282 cur_nb_packets++;
4283 }
4284 if (!cur_nb_packets) {
4285 /* Not enough room to grab one packet of each stream, error. */
4286 return -1;
4287 }
4288 return cur_nb_packets;
4289 }
4290
4291 /*
4292 * Command LTTNG_SNAPSHOT_RECORD from lib lttng ctl.
4293 *
4294 * The wait parameter is ignored so this call always wait for the snapshot to
4295 * complete before returning.
4296 *
4297 * Return LTTNG_OK on success or else a LTTNG_ERR code.
4298 */
4299 int cmd_snapshot_record(struct ltt_session *session,
4300 struct lttng_snapshot_output *output, int wait)
4301 {
4302 enum lttng_error_code cmd_ret = LTTNG_OK;
4303 int ret;
4304 unsigned int use_tmp_output = 0;
4305 struct snapshot_output tmp_output;
4306 unsigned int snapshot_success = 0;
4307 char datetime[16];
4308
4309 assert(session);
4310 assert(output);
4311
4312 DBG("Cmd snapshot record for session %s", session->name);
4313
4314 /* Get the datetime for the snapshot output directory. */
4315 ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
4316 sizeof(datetime));
4317 if (!ret) {
4318 cmd_ret = LTTNG_ERR_INVALID;
4319 goto error;
4320 }
4321
4322 /*
4323 * Permission denied to create an output if the session is not
4324 * set in no output mode.
4325 */
4326 if (session->output_traces) {
4327 cmd_ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
4328 goto error;
4329 }
4330
4331 /* The session needs to be started at least once. */
4332 if (!session->has_been_started) {
4333 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4334 goto error;
4335 }
4336
4337 /* Use temporary output for the session. */
4338 if (*output->ctrl_url != '\0') {
4339 ret = snapshot_output_init(output->max_size, output->name,
4340 output->ctrl_url, output->data_url, session->consumer,
4341 &tmp_output, NULL);
4342 if (ret < 0) {
4343 if (ret == -ENOMEM) {
4344 cmd_ret = LTTNG_ERR_NOMEM;
4345 } else {
4346 cmd_ret = LTTNG_ERR_INVALID;
4347 }
4348 goto error;
4349 }
4350 /* Use the global session count for the temporary snapshot. */
4351 tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
4352
4353 /* Use the global datetime */
4354 memcpy(tmp_output.datetime, datetime, sizeof(datetime));
4355 use_tmp_output = 1;
4356 }
4357
4358 if (use_tmp_output) {
4359 int64_t nb_packets_per_stream;
4360
4361 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4362 tmp_output.max_size);
4363 if (nb_packets_per_stream < 0) {
4364 cmd_ret = LTTNG_ERR_MAX_SIZE_INVALID;
4365 goto error;
4366 }
4367
4368 if (session->kernel_session) {
4369 cmd_ret = record_kernel_snapshot(session->kernel_session,
4370 &tmp_output, session,
4371 wait, nb_packets_per_stream);
4372 if (cmd_ret != LTTNG_OK) {
4373 goto error;
4374 }
4375 }
4376
4377 if (session->ust_session) {
4378 cmd_ret = record_ust_snapshot(session->ust_session,
4379 &tmp_output, session,
4380 wait, nb_packets_per_stream);
4381 if (cmd_ret != LTTNG_OK) {
4382 goto error;
4383 }
4384 }
4385
4386 snapshot_success = 1;
4387 } else {
4388 struct snapshot_output *sout;
4389 struct lttng_ht_iter iter;
4390
4391 rcu_read_lock();
4392 cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
4393 &iter.iter, sout, node.node) {
4394 int64_t nb_packets_per_stream;
4395
4396 /*
4397 * Make a local copy of the output and assign the possible
4398 * temporary value given by the caller.
4399 */
4400 memset(&tmp_output, 0, sizeof(tmp_output));
4401 memcpy(&tmp_output, sout, sizeof(tmp_output));
4402
4403 if (output->max_size != (uint64_t) -1ULL) {
4404 tmp_output.max_size = output->max_size;
4405 }
4406
4407 nb_packets_per_stream = get_session_nb_packets_per_stream(session,
4408 tmp_output.max_size);
4409 if (nb_packets_per_stream < 0) {
4410 cmd_ret = LTTNG_ERR_MAX_SIZE_INVALID;
4411 rcu_read_unlock();
4412 goto error;
4413 }
4414
4415 /* Use temporary name. */
4416 if (*output->name != '\0') {
4417 if (lttng_strncpy(tmp_output.name, output->name,
4418 sizeof(tmp_output.name))) {
4419 cmd_ret = LTTNG_ERR_INVALID;
4420 rcu_read_unlock();
4421 goto error;
4422 }
4423 }
4424
4425 tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
4426 memcpy(tmp_output.datetime, datetime, sizeof(datetime));
4427
4428 if (session->kernel_session) {
4429 cmd_ret = record_kernel_snapshot(session->kernel_session,
4430 &tmp_output, session,
4431 wait, nb_packets_per_stream);
4432 if (cmd_ret != LTTNG_OK) {
4433 rcu_read_unlock();
4434 goto error;
4435 }
4436 }
4437
4438 if (session->ust_session) {
4439 cmd_ret = record_ust_snapshot(session->ust_session,
4440 &tmp_output, session,
4441 wait, nb_packets_per_stream);
4442 if (cmd_ret != LTTNG_OK) {
4443 rcu_read_unlock();
4444 goto error;
4445 }
4446 }
4447 snapshot_success = 1;
4448 }
4449 rcu_read_unlock();
4450 }
4451
4452 if (snapshot_success) {
4453 session->snapshot.nb_snapshot++;
4454 } else {
4455 cmd_ret = LTTNG_ERR_SNAPSHOT_FAIL;
4456 }
4457
4458 error:
4459 return cmd_ret;
4460 }
4461
4462 /*
4463 * Command LTTNG_SET_SESSION_SHM_PATH processed by the client thread.
4464 */
4465 int cmd_set_session_shm_path(struct ltt_session *session,
4466 const char *shm_path)
4467 {
4468 /* Safety net */
4469 assert(session);
4470
4471 /*
4472 * Can only set shm path before session is started.
4473 */
4474 if (session->has_been_started) {
4475 return LTTNG_ERR_SESSION_STARTED;
4476 }
4477
4478 strncpy(session->shm_path, shm_path,
4479 sizeof(session->shm_path));
4480 session->shm_path[sizeof(session->shm_path) - 1] = '\0';
4481
4482 return 0;
4483 }
4484
4485 /*
4486 * Command LTTNG_ROTATE_SESSION from the lttng-ctl library.
4487 *
4488 * Ask the consumer to rotate the session output directory.
4489 * The session lock must be held.
4490 *
4491 * Returns LTTNG_OK on success or else a negative LTTng error code.
4492 */
4493 int cmd_rotate_session(struct ltt_session *session,
4494 struct lttng_rotate_session_return *rotate_return)
4495 {
4496 int ret;
4497 enum lttng_error_code cmd_ret = LTTNG_OK;
4498 size_t strf_ret;
4499 struct tm *timeinfo;
4500 char datetime[21];
4501 time_t now;
4502 /*
4503 * Used to roll-back timestamps in case of failure to launch the
4504 * rotation.
4505 */
4506 time_t original_last_chunk_start_ts, original_current_chunk_start_ts;
4507
4508 assert(session);
4509
4510 if (!session->has_been_started) {
4511 cmd_ret = LTTNG_ERR_START_SESSION_ONCE;
4512 goto end;
4513 }
4514
4515 if (session->live_timer || !session->output_traces) {
4516 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
4517 goto end;
4518 }
4519
4520 /*
4521 * Unsupported feature in lttng-relayd before 2.11.
4522 */
4523 if (session->consumer->type == CONSUMER_DST_NET &&
4524 (session->consumer->relay_major_version == 2 &&
4525 session->consumer->relay_minor_version < 11)) {
4526 cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_RELAY;
4527 goto end;
4528 }
4529
4530 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
4531 DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
4532 session->name);
4533 cmd_ret = LTTNG_ERR_ROTATION_PENDING;
4534 goto end;
4535 }
4536
4537 /*
4538 * After a stop, we only allow one rotation to occur, the other ones are
4539 * useless until a new start.
4540 */
4541 if (session->rotated_after_last_stop) {
4542 DBG("Session \"%s\" was already rotated after stop, refusing rotation",
4543 session->name);
4544 cmd_ret = LTTNG_ERR_ROTATION_MULTIPLE_AFTER_STOP;
4545 goto end;
4546 }
4547
4548 /* Special case for the first rotation. */
4549 if (session->current_archive_id == 0) {
4550 const char *base_path = NULL;
4551
4552 assert(session->kernel_session || session->ust_session);
4553 /* Either one of the two sessions is enough to get the root path. */
4554 base_path = session_get_base_path(session);
4555 assert(base_path);
4556
4557 ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
4558 base_path,
4559 sizeof(session->rotation_chunk.current_rotate_path));
4560 if (ret) {
4561 ERR("Failed to copy session base path to current rotation chunk path");
4562 cmd_ret = LTTNG_ERR_UNK;
4563 goto end;
4564 }
4565 } else {
4566 /*
4567 * The currently active tracing path is now the folder we
4568 * want to rotate.
4569 */
4570 ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
4571 session->rotation_chunk.active_tracing_path,
4572 sizeof(session->rotation_chunk.current_rotate_path));
4573 if (ret) {
4574 ERR("Failed to copy the active tracing path to the current rotate path");
4575 cmd_ret = LTTNG_ERR_UNK;
4576 goto end;
4577 }
4578 }
4579 DBG("Current rotate path %s", session->rotation_chunk.current_rotate_path);
4580
4581 /*
4582 * Channels created after this point will belong to the next
4583 * archive id.
4584 */
4585 session->current_archive_id++;
4586
4587 now = time(NULL);
4588 if (now == (time_t) -1) {
4589 cmd_ret = LTTNG_ERR_UNK;
4590 goto end;
4591 }
4592
4593 /* Sample chunk bounds for roll-back in case of error. */
4594 original_last_chunk_start_ts = session->last_chunk_start_ts;
4595 original_current_chunk_start_ts = session->current_chunk_start_ts;
4596
4597 session->last_chunk_start_ts = session->current_chunk_start_ts;
4598 session->current_chunk_start_ts = now;
4599
4600 timeinfo = localtime(&now);
4601 if (!timeinfo) {
4602 PERROR("Failed to sample local time in rotate session command");
4603 cmd_ret = LTTNG_ERR_UNK;
4604 goto end;
4605 }
4606 strf_ret = strftime(datetime, sizeof(datetime), "%Y%m%dT%H%M%S%z",
4607 timeinfo);
4608 if (!strf_ret) {
4609 ERR("Failed to format local time timestamp in rotate session command");
4610 cmd_ret = LTTNG_ERR_UNK;
4611 goto end;
4612 }
4613
4614 /*
4615 * A rotation has a local step even if the destination is a relay
4616 * daemon; the buffers must be consumed by the consumer daemon.
4617 */
4618 session->rotation_pending_local = true;
4619 session->rotation_pending_relay =
4620 session_get_consumer_destination_type(session) == CONSUMER_DST_NET;
4621 session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
4622
4623 if (session->kernel_session) {
4624 /*
4625 * The active path for the next rotation/destroy.
4626 * Ex: ~/lttng-traces/auto-20170922-111748/20170922-111754-42
4627 */
4628 ret = snprintf(session->rotation_chunk.active_tracing_path,
4629 sizeof(session->rotation_chunk.active_tracing_path),
4630 "%s/%s-%" PRIu64,
4631 session_get_base_path(session),
4632 datetime, session->current_archive_id + 1);
4633 if (ret < 0 || ret == sizeof(session->rotation_chunk.active_tracing_path)) {
4634 ERR("Failed to format active kernel tracing path in rotate session command");
4635 cmd_ret = LTTNG_ERR_UNK;
4636 goto error;
4637 }
4638 /*
4639 * The sub-directory for the consumer
4640 * Ex: /20170922-111754-42/kernel
4641 */
4642 ret = snprintf(session->kernel_session->consumer->chunk_path,
4643 sizeof(session->kernel_session->consumer->chunk_path),
4644 "/%s-%" PRIu64, datetime,
4645 session->current_archive_id + 1);
4646 if (ret < 0 || ret == sizeof(session->kernel_session->consumer->chunk_path)) {
4647 ERR("Failed to format the kernel consumer's sub-directory in rotate session command");
4648 cmd_ret = LTTNG_ERR_UNK;
4649 goto error;
4650 }
4651 /*
4652 * Create the new chunk folder, before the rotation begins so we don't
4653 * race with the consumer/tracer activity.
4654 */
4655 ret = domain_mkdir(session->kernel_session->consumer, session,
4656 session->kernel_session->uid,
4657 session->kernel_session->gid);
4658 if (ret) {
4659 ERR("Failed to create kernel session tracing path at %s",
4660 session->kernel_session->consumer->chunk_path);
4661 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
4662 goto error;
4663 }
4664 cmd_ret = kernel_rotate_session(session);
4665 if (cmd_ret != LTTNG_OK) {
4666 goto error;
4667 }
4668 }
4669 if (session->ust_session) {
4670 ret = snprintf(session->rotation_chunk.active_tracing_path,
4671 PATH_MAX, "%s/%s-%" PRIu64,
4672 session_get_base_path(session),
4673 datetime, session->current_archive_id + 1);
4674 if (ret < 0) {
4675 ERR("Failed to format active UST tracing path in rotate session command");
4676 cmd_ret = LTTNG_ERR_UNK;
4677 goto error;
4678 }
4679 ret = snprintf(session->ust_session->consumer->chunk_path,
4680 PATH_MAX, "/%s-%" PRIu64, datetime,
4681 session->current_archive_id + 1);
4682 if (ret < 0) {
4683 ERR("Failed to format the UST consumer's sub-directory in rotate session command");
4684 cmd_ret = LTTNG_ERR_UNK;
4685 goto error;
4686 }
4687 /*
4688 * Create the new chunk folder, before the rotation begins so we don't
4689 * race with the consumer/tracer activity.
4690 */
4691 ret = domain_mkdir(session->ust_session->consumer, session,
4692 session->ust_session->uid,
4693 session->ust_session->gid);
4694 if (ret) {
4695 cmd_ret = LTTNG_ERR_CREATE_DIR_FAIL;
4696 goto error;
4697 }
4698 cmd_ret = ust_app_rotate_session(session);
4699 if (cmd_ret != LTTNG_OK) {
4700 goto error;
4701 }
4702 }
4703
4704 ret = timer_session_rotation_pending_check_start(session,
4705 DEFAULT_ROTATE_PENDING_TIMER);
4706 if (ret) {
4707 cmd_ret = LTTNG_ERR_UNK;
4708 goto error;
4709 }
4710
4711 if (!session->active) {
4712 session->rotated_after_last_stop = true;
4713 }
4714
4715 if (rotate_return) {
4716 rotate_return->rotation_id = session->current_archive_id;
4717 }
4718
4719 ret = notification_thread_command_session_rotation_ongoing(
4720 notification_thread_handle,
4721 session->name, session->uid, session->gid,
4722 session->current_archive_id - 1);
4723 if (ret != LTTNG_OK) {
4724 ERR("Failed to notify notification thread that a session rotation is ongoing for session %s",
4725 session->name);
4726 cmd_ret = ret;
4727 }
4728
4729 DBG("Cmd rotate session %s, archive_id %" PRIu64 " sent",
4730 session->name, session->current_archive_id - 1);
4731 end:
4732 ret = (cmd_ret == LTTNG_OK) ? cmd_ret : -((int) cmd_ret);
4733 return ret;
4734 error:
4735 session->last_chunk_start_ts = original_last_chunk_start_ts;
4736 session->current_archive_id = original_current_chunk_start_ts;
4737 if (session_reset_rotation_state(session,
4738 LTTNG_ROTATION_STATE_NO_ROTATION)) {
4739 ERR("Failed to reset rotation state of session \"%s\"",
4740 session->name);
4741 }
4742 goto end;
4743 }
4744
4745 /*
4746 * Command LTTNG_ROTATION_GET_INFO from the lttng-ctl library.
4747 *
4748 * Check if the session has finished its rotation.
4749 *
4750 * Return 0 on success or else a LTTNG_ERR code.
4751 */
4752 int cmd_rotate_get_info(struct ltt_session *session,
4753 struct lttng_rotation_get_info_return *info_return,
4754 uint64_t rotation_id)
4755 {
4756 int ret;
4757
4758 assert(session);
4759
4760 DBG("Cmd rotate_get_info session %s, rotation id %" PRIu64, session->name,
4761 session->current_archive_id);
4762
4763 if (session->current_archive_id != rotation_id) {
4764 info_return->status = (int32_t) LTTNG_ROTATION_STATE_EXPIRED;
4765 ret = LTTNG_OK;
4766 goto end;
4767 }
4768
4769 switch (session->rotation_state) {
4770 case LTTNG_ROTATION_STATE_ONGOING:
4771 DBG("Reporting that rotation id %" PRIu64 " of session %s is still pending",
4772 rotation_id, session->name);
4773 break;
4774 case LTTNG_ROTATION_STATE_COMPLETED:
4775 {
4776 char *current_tracing_path_reply;
4777 size_t current_tracing_path_reply_len;
4778
4779 switch (session_get_consumer_destination_type(session)) {
4780 case CONSUMER_DST_LOCAL:
4781 current_tracing_path_reply =
4782 info_return->location.local.absolute_path;
4783 current_tracing_path_reply_len =
4784 sizeof(info_return->location.local.absolute_path);
4785 info_return->location_type =
4786 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_LOCAL;
4787 break;
4788 case CONSUMER_DST_NET:
4789 current_tracing_path_reply =
4790 info_return->location.relay.relative_path;
4791 current_tracing_path_reply_len =
4792 sizeof(info_return->location.relay.relative_path);
4793 /* Currently the only supported relay protocol. */
4794 info_return->location.relay.protocol =
4795 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP;
4796
4797 ret = lttng_strncpy(info_return->location.relay.host,
4798 session_get_net_consumer_hostname(session),
4799 sizeof(info_return->location.relay.host));
4800 if (ret) {
4801 ERR("Failed to host name to rotate_get_info reply");
4802 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
4803 ret = -LTTNG_ERR_UNK;
4804 goto end;
4805 }
4806
4807 session_get_net_consumer_ports(session,
4808 &info_return->location.relay.ports.control,
4809 &info_return->location.relay.ports.data);
4810 info_return->location_type =
4811 (int8_t) LTTNG_TRACE_ARCHIVE_LOCATION_TYPE_RELAY;
4812 break;
4813 default:
4814 abort();
4815 }
4816 ret = lttng_strncpy(current_tracing_path_reply,
4817 session->rotation_chunk.current_rotate_path,
4818 current_tracing_path_reply_len);
4819 if (ret) {
4820 ERR("Failed to copy current tracing path to rotate_get_info reply");
4821 info_return->status = LTTNG_ROTATION_STATUS_ERROR;
4822 ret = -LTTNG_ERR_UNK;
4823 goto end;
4824 }
4825
4826 break;
4827 }
4828 case LTTNG_ROTATION_STATE_ERROR:
4829 DBG("Reporting that an error occurred during rotation %" PRIu64 " of session %s",
4830 rotation_id, session->name);
4831 break;
4832 default:
4833 abort();
4834 }
4835
4836 info_return->status = (int32_t) session->rotation_state;
4837 ret = LTTNG_OK;
4838 end:
4839 return ret;
4840 }
4841
4842 /*
4843 * Command LTTNG_ROTATION_SET_SCHEDULE from the lttng-ctl library.
4844 *
4845 * Configure the automatic rotation parameters.
4846 * 'activate' to true means activate the rotation schedule type with 'new_value'.
4847 * 'activate' to false means deactivate the rotation schedule and validate that
4848 * 'new_value' has the same value as the currently active value.
4849 *
4850 * Return 0 on success or else a positive LTTNG_ERR code.
4851 */
4852 int cmd_rotation_set_schedule(struct ltt_session *session,
4853 bool activate, enum lttng_rotation_schedule_type schedule_type,
4854 uint64_t new_value,
4855 struct notification_thread_handle *notification_thread_handle)
4856 {
4857 int ret;
4858 uint64_t *parameter_value;
4859
4860 assert(session);
4861
4862 DBG("Cmd rotate set schedule session %s", session->name);
4863
4864 if (session->live_timer || !session->output_traces) {
4865 DBG("Failing ROTATION_SET_SCHEDULE command as the rotation feature is not available for this session");
4866 ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
4867 goto end;
4868 }
4869
4870 switch (schedule_type) {
4871 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
4872 parameter_value = &session->rotate_size;
4873 break;
4874 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
4875 parameter_value = &session->rotate_timer_period;
4876 if (new_value >= UINT_MAX) {
4877 DBG("Failing ROTATION_SET_SCHEDULE command as the value requested for a periodic rotation schedule is invalid: %" PRIu64 " > %u (UINT_MAX)",
4878 new_value, UINT_MAX);
4879 ret = LTTNG_ERR_INVALID;
4880 goto end;
4881 }
4882 break;
4883 default:
4884 WARN("Failing ROTATION_SET_SCHEDULE command on unknown schedule type");
4885 ret = LTTNG_ERR_INVALID;
4886 goto end;
4887 }
4888
4889 /* Improper use of the API. */
4890 if (new_value == -1ULL) {
4891 WARN("Failing ROTATION_SET_SCHEDULE command as the value requested is -1");
4892 ret = LTTNG_ERR_INVALID;
4893 goto end;
4894 }
4895
4896 /*
4897 * As indicated in struct ltt_session's comments, a value of == 0 means
4898 * this schedule rotation type is not in use.
4899 *
4900 * Reject the command if we were asked to activate a schedule that was
4901 * already active.
4902 */
4903 if (activate && *parameter_value != 0) {
4904 DBG("Failing ROTATION_SET_SCHEDULE (activate) command as the schedule is already active");
4905 ret = LTTNG_ERR_ROTATION_SCHEDULE_SET;
4906 goto end;
4907 }
4908
4909 /*
4910 * Reject the command if we were asked to deactivate a schedule that was
4911 * not active.
4912 */
4913 if (!activate && *parameter_value == 0) {
4914 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as the schedule is already inactive");
4915 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
4916 goto end;
4917 }
4918
4919 /*
4920 * Reject the command if we were asked to deactivate a schedule that
4921 * doesn't exist.
4922 */
4923 if (!activate && *parameter_value != new_value) {
4924 DBG("Failing ROTATION_SET_SCHEDULE (deactivate) command as an inexistant schedule was provided");
4925 ret = LTTNG_ERR_ROTATION_SCHEDULE_NOT_SET;
4926 goto end;
4927 }
4928
4929 *parameter_value = activate ? new_value : 0;
4930
4931 switch (schedule_type) {
4932 case LTTNG_ROTATION_SCHEDULE_TYPE_PERIODIC:
4933 if (activate && session->active) {
4934 /*
4935 * Only start the timer if the session is active,
4936 * otherwise it will be started when the session starts.
4937 */
4938 ret = timer_session_rotation_schedule_timer_start(
4939 session, new_value);
4940 if (ret) {
4941 ERR("Failed to enable session rotation timer in ROTATION_SET_SCHEDULE command");
4942 ret = LTTNG_ERR_UNK;
4943 goto end;
4944 }
4945 } else {
4946 ret = timer_session_rotation_schedule_timer_stop(
4947 session);
4948 if (ret) {
4949 ERR("Failed to disable session rotation timer in ROTATION_SET_SCHEDULE command");
4950 ret = LTTNG_ERR_UNK;
4951 goto end;
4952 }
4953 }
4954 break;
4955 case LTTNG_ROTATION_SCHEDULE_TYPE_SIZE_THRESHOLD:
4956 if (activate) {
4957 ret = subscribe_session_consumed_size_rotation(session,
4958 new_value, notification_thread_handle);
4959 if (ret) {
4960 ERR("Failed to enable consumed-size notification in ROTATION_SET_SCHEDULE command");
4961 ret = LTTNG_ERR_UNK;
4962 goto end;
4963 }
4964 } else {
4965 ret = unsubscribe_session_consumed_size_rotation(session,
4966 notification_thread_handle);
4967 if (ret) {
4968 ERR("Failed to disable consumed-size notification in ROTATION_SET_SCHEDULE command");
4969 ret = LTTNG_ERR_UNK;
4970 goto end;
4971 }
4972
4973 }
4974 break;
4975 default:
4976 /* Would have been caught before. */
4977 abort();
4978 }
4979
4980 ret = LTTNG_OK;
4981
4982 goto end;
4983
4984 end:
4985 return ret;
4986 }
4987
4988 /* Wait for a given path to be removed before continuing. */
4989 static enum lttng_error_code wait_on_path(void *path_data)
4990 {
4991 const char *shm_path = path_data;
4992
4993 DBG("Waiting for the shm path at %s to be removed before completing session destruction",
4994 shm_path);
4995 while (true) {
4996 int ret;
4997 struct stat st;
4998
4999 ret = stat(shm_path, &st);
5000 if (ret) {
5001 if (errno != ENOENT) {
5002 PERROR("stat() returned an error while checking for the existence of the shm path");
5003 } else {
5004 DBG("shm path no longer exists, completing the destruction of session");
5005 }
5006 break;
5007 } else {
5008 if (!S_ISDIR(st.st_mode)) {
5009 ERR("The type of shm path %s returned by stat() is not a directory; aborting the wait for shm path removal",
5010 shm_path);
5011 break;
5012 }
5013 }
5014 usleep(SESSION_DESTROY_SHM_PATH_CHECK_DELAY_US);
5015 }
5016 return LTTNG_OK;
5017 }
5018
5019 /*
5020 * Returns a pointer to a handler to run on completion of a command.
5021 * Returns NULL if no handler has to be run for the last command executed.
5022 */
5023 const struct cmd_completion_handler *cmd_pop_completion_handler(void)
5024 {
5025 struct cmd_completion_handler *handler = current_completion_handler;
5026
5027 current_completion_handler = NULL;
5028 return handler;
5029 }
5030
5031 /*
5032 * Init command subsystem.
5033 */
5034 void cmd_init(void)
5035 {
5036 /*
5037 * Set network sequence index to 1 for streams to match a relayd
5038 * socket on the consumer side.
5039 */
5040 pthread_mutex_lock(&relayd_net_seq_idx_lock);
5041 relayd_net_seq_idx = 1;
5042 pthread_mutex_unlock(&relayd_net_seq_idx_lock);
5043
5044 DBG("Command subsystem initialized");
5045 }
LTTng 2.0 tools and control repository
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